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  • 1985-1989  (62)
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  • 1
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-84/4
    In: CRREL Report, 84-4
    Description / Table of Contents: Ice problems developed in the Sault Ste. Marie, Michigan, portion of the St. Marys River because of winter navigation. Passing ships and natural influences moved ice from Soo Harbor into Little Rapids Cut in sufficient quantities to jam, cause high water in the harbor, and prevent further ship passage. After physical model and engineering studies, two ice booms with a total span of 1375 ft (419 m) with a 250-ft (76-m) navigation opening between were installed at the head of Little Rapids Cut in 1975. A modest field study program on the booms was conducted for the ensuring four winters to determine ice and boom interaction and the effects of ship passages on the system. Forces on some anchors were recorded and supplemental data were taken by local personnel. Several reports have been written about the booms' early operations. This paper presents four-year summary of the main effects of the booms on ice and ship interaction and vice versa. Throughout the four winter seasons, the small quantities of ice lost over and between the booms were manageable. Ships usually passed through the boom without influencing the boom force levels, but at time they brought about large changes. One boom needed strengthening, and artificial islands were added for upstream ice stability. Coast Guard icebreakers were also a necessary part of winter navigation in this area.
    Type of Medium: Series available for loan
    Pages: iv, 18 Seiten , Illustrationen
    Series Statement: CRREL Report 84-4
    Language: English
    Note: CONTENTS Abstract Preface Introduction St. Marys River Ice problems Remedial measures Field studies Highlights, trends, and major findings Modifications to boom Maximum forces Ship traffic Characteristics Effect of boom forces Effect on ice Conclusion Literature cited Appendix A: Ice boom forces
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  • 2
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-84/7
    In: CRREL Report, 84-7
    Description / Table of Contents: Experiments were conducted in CRREL's refrigerated flume facility to examine the two-dimensional force distribution of a floating, fragmented ice cover restrained by a boom in a simulated river channel. To determine the force distribution, a vertically walled channel, instrumented for measuring normal and tangential forces, and an instrumented restraining boom were installed in a 40.0- by 1.3-m flume. Two sizes of polyethylene blocks and two similar sizes of fresh-water ice blocks were tested using water velocities ranging from 10 to 30 cm/s. The forces measured at the instrumented boom leveled off with increasing cover length. The contribution of the increasing shear forces developed along theshorelines to this leveling off in the data was clearly evident. The shear coefficients of the polyethylene blocks averaged 0.43, and the freshwater ice averaged 0.044. The normal force measured along the instrumented shoreline could not be related simply by a K coefficient to the longitudinal force; another expression was required, with a term being a function of the cover thickness and independent of the undercover shear stress or cover length. By adding this term, good agreement was then found between the measured and predicted values of the boom forces and the shoreline normal and shear forces
    Type of Medium: Series available for loan
    Pages: iv, 22 Seiten , Illustrationen
    Series Statement: CRREL Report 84-7
    Language: English
    Note: CONTENTS Abstract Preface Introduction Experiments Test flume facility Experimental apparatus Experimental procedure Results Plastic versus freshwater ice Shoreline forces Boom forces Average shear stress under ice cover Internal forces Discussion Data scatter Summary and conclusions Literature cited Appendix A: Experimental results
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  • 3
    Call number: ZSP-201-86/13
    In: CRREL Report, 86-13
    Description / Table of Contents: Stress-deformation data for six granular soils ranging from sandy silt to dense-graded crushedstone were obtained from in-situ tests and laboratory tests. Surface deflections were measured in the in-situ tests, with repeated-load plate-bearing and falling-weight deflectometer equipment, when the six granular soils were frozen, thawed, and at various stages of recovery from thaw weakening. The measured deflections were used to judge the validity of procedures developed for laboratory triaxial tests to determine nonlinear resilient moduli of specimens in the frozen, thawed, and recovering states. The validity of the nonlinear resilient moduli, expressed as functions of externally applied stress and moisture tension, was confirmed by using the expressions tocalculate surface deflections that were found to compare well with deflections measured in the in-situ tests. The tests on specimens at various stages of recovery are especially significant because they show a strong dependence of the resilient modulus on moisture tension, leading to the conclusion that predictions or in-situ measurements of moisture tension can be used to evaluate expected seasonal variation in the resilient modulus of granular soils.
    Type of Medium: Series available for loan
    Pages: iv, 148 Seiten , Illustrationen
    Series Statement: CRREL Report 86-13
    Language: English
    Note: CONTENTS Abstract Preface Introduction Test sections Installing instruments and sampling Laboratory tests Asphalt concrete Base, subbase and subgrade soils Data analysis for base, subbase and subgrade soils Field tests Analysis of plate loading tests Analytical approach Results Discussion Conclusions Literature cited Appendix A: Field data Appendix B: Ground temperatures, moisture tension, water table and freezing iso-therms prevailing during plate loading tests Appendix C: Measured surface deflections compared with deflections calculated by NELAPAV Appendix D: Resilient moduli and supporting data calculated by NELAPA V at radius 0.0, taxiways A and B.
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  • 4
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-84/33
    In: CRREL Report, 84-33
    Description / Table of Contents: A small-scale experimental study was conducted to characterize the magnitude and nature of ice forces during continuous crushing of ice against a rigid, vertical, cylindrical structure. The diameter of the structure was varied from 50 to 500 mm, the relative velocity from 10 to 210 mm/s, and the ice thickness from 50 to 80 mm. The ice tended to fail repetitively, with the frequency of failure termed the characteristic frequency. The characteristic frequency varied linearly with velocity and to a small extent with structure diameter. The size of the damage zone was 10 to 50% of the ice thickness, with an average value of 30%. The maximum and mean normalized ice forces were strongly dependent on the aspect ratio (structure diameter/ice thickness). The forces increased significantly with decreasing aspect ratio, but were constant for large aspect ratios. The maximum normalized forces appeared to be independent of strain rate. The effect of velocity on the normalized ice forces depended on structure diameter. The mean effective pressure or specific energy of ice crushing depended on both aspect ratio and ice-structure relative velocity. The energy required to crush the ice for the one failure cycle was obtained from the ice force records for each test, and was compared to the energy calculated from an idealized sawtooth shape for the force record, the maximum force, velocity and characteristic frequency data. Originator - supplied keywords included: Cold regions, Cold regions construction, Cylindrical test structures, Ice, Ice crushing, Ice forces, and Test facilities.
    Type of Medium: Series available for loan
    Pages: vi, 47 Seiten , Illustrationen
    Series Statement: CRREL Report 84-33
    Language: English
    Note: Contents Abstract Preface Nomenclature Introduction Test objectives Experimental setup and procedures Facilities Test fixture Data acquisiton system Ice sheets Measurement of ice properties Daily test summary Experimental results and discussion Observations Ice force records Frequency of ice force variations Discussion Maximum crushing forces Mean effective pressure or specific energy of ice in crushing Failure energy of ice Ratio of maximum force to mean force Summary and conclusions Literature cited Appendix A: Data for continuous crushing tests
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  • 5
    Call number: ZSP-SCAR-570-10
    In: National Antarctic Research Report to SCAR, 10
    Type of Medium: Series available for loan
    Pages: 61 Seiten
    ISSN: 0179-0072
    Series Statement: National Antarctic Research Report to SCAR 10
    Language: English
    Note: Contents: Membership of the National Committee on Antarctic Research in the Federal Republic of Germany. - Members of Permanent Working Groups and Groups of Specialists of SCAR. - Introduction. - Stations. - I. Record of Activities (past and ongoing), April 1987 - October 1988. - II. Planned Activities, October 1988 - October 1989. - References. - Addenda to Former Reports. - Index of Activities.
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  • 6
    Call number: ZSP-SCAR-570-9
    In: National Antarctic Research Report to SCAR, No. 9
    Type of Medium: Series available for loan
    Pages: 34 Seiten
    ISSN: 0179-0072
    Series Statement: National Antarctic Research Report to SCAR 9
    Language: English
    Note: Contents: Membership of the National Committee on Antarctic Research in the Federal Republic of Germany. - Members of Permanent Working Groups and Groups of Specialists of SCAR. - Introduction. - Stations. - I. Record of Activities (past and ongoing), April 1986 - October 1987. - II. Planned Activities, October 1987 - October 1988. - References. - Addenda to Former Reports. - Index of Activities.
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  • 7
    Call number: ZSP-SCAR-570-6
    In: Antarctic Research Report to SCAR, No. 6
    Type of Medium: Series available for loan
    Pages: 38 Seiten
    ISSN: 0179-0072
    Series Statement: National Antarctic Research Report to SCAR 6
    Language: English
    Note: Contents: Membership of the National Committee on Antarctic Research in the Federal Republic of Germany. - Introduction. - Stations. - I. Record of Activities (past and ongoing), April 83-October 84. - II. Planned Activities, October 84-October 85. - References.
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  • 8
    Call number: ZSP-SCAR-570-3
    In: National Antarctic Research Report to SCAR, No. 3
    Type of Medium: Series available for loan
    Pages: 16 Seiten
    ISSN: 0179-0072
    Series Statement: National Antarctic Research Report to SCAR 3
    Language: English
    Note: Contents: Membership of the National Committee on Antarctic Research in the Federal Republic of Germany. - Introduction. - Stations. - I. Record of Activities (past and ongoing), April 80-October 81. - II. Planned Activities, October 81-October 82. - References.
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  • 9
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-87/15
    In: CRREL Report, 87-15
    Description / Table of Contents: Constant strain-rate tension tests were conducted on remolded saturated frozen Fairbanks silt at various temperatures, strain rates, and densities. It was found that the critical strain rate of the ductile-brittle transition is not temperature-dependent at temperatures down to -5°C, but varies with density. The peak tensile strength decreases considerable with decreasing strain rate for ductile failure, but it decreases slightly with increasing strain rate for brittle fracture. The failure strain remains almost constant at temperatures lower than about -2°C, but it varies with density and strain rate at -5°C. The initial tangent modulus is independent of strain rate and increases with decreasing temperature and density.
    Type of Medium: Series available for loan
    Pages: v, 29 Seiten , Illustrationen
    Series Statement: CRREL Report 87-15
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Testing Material Specimen preparation Testing procedure and apparatus Results Discussion Peak tensile strength, σm Failure tensile strain, ϵf Initial tangent modulus and 50% peak strength modulus Discussion of test techniques Conclusions Literature cited Appendix A: Physical properties of Fairbanks silt specimens Appendix B: Unfrozen water content data of Fairbanks silt with three typical water contents
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  • 10
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-87/21
    In: CRREL Report, 87-21
    Description / Table of Contents: The author measured time series of longitudinal (u) and vertical (w) velocity and temperature (t) and humidity (q) fluctuations with fast-responding sensors in the near-neutrally stable surface layer over a snow-covered field. These series yielded individual spectra and u-w, w-t, w-q and t-q cospectra, phase spectra and coherence spectra for nondimensional frequencies (fz/U) from roughly 0.001 to 10. With the exception of the u-w cospectra, all the spectra and cospectra displayed the expected dependence on frequency in an inertial or inertial-convective subrange. All, however, contained significantly more energy at low frequency than the Kansas neutral-stability spectra and cospectra. This excess low-frequency energy and the erratic behavior of the u-w cospectra imply that forested hills bordering the site on two sides were producing disturbances in the flow field at scales roughly equal to the height of the hills, 100 m. The phase and coherence spectra suggest that internal gravity waves were also frequently present, since the atmospheric boundary layer generally had slightly stable stratification. Consequently, at this complex site, turbulence alone determines the spectra and cospectra at high frequency; at low frequency the spectra and cospectra reflect a combination of topographically generated turbulence and internal waves. From the measured temperature and humidity spectra and the t-q cospectra, the author computed refractive index spectra for light of 0.55-micrometer and millimeter wavelengths. The refractive index spectra had shapes like the other scalar spectra: excess energy at low frequency and an inertial-convective subrange at high frequency.
    Type of Medium: Series available for loan
    Pages: v, 50 Seiten , Illustrationen
    Series Statement: CRREL Report 87-21
    Language: English
    Note: CONTENTS Abstract Preface Introduction Measurements Spectra u and w velocity spectra Temperature and humidity spectra Inertial-dissipation estimates Cospectra u-w cospectra w-t and w-q cospectra t-q cospectra Refractive index spectra Conclusions Literature cited
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  • 11
    Call number: ZSP-SCAR-570-7
    In: National Antarctic Research Report to SCAR, No. 7
    Type of Medium: Series available for loan
    Pages: 37 Seiten , 2 Beilagen
    ISSN: 0179-0072
    Series Statement: National Antarctic Research Report to SCAR 7
    Language: English
    Note: 1 Kartenbeilage unter dem Titel: Neuschwabenland (West) 〈1 : 2.000.000〉, Bildflugroutenübersicht Antarktis-Expediton 1983/84 = Aerial Survey Route Map. - 2. Ausgabe. - Frankfurt am Main : Institut für Angewandte Geodäsie (IfAG), 1985. , 1 Beilage unter dem Titel: Supplement to National Antarctic Research Report to SCAR, No. 7 (July 1985) , Contents: Membership of the National Committee on Antarctic Research in the Federal Republic of Germany. - Members of Permanent Working Groups and Groups of Specialists of SCAR. - Introduction. - Stations. - I. Record of Activities (past and ongoing), April 84-October 85. - II. Planned Activities, October 1985 - October 1986. - References. - Addenda to Former Reports. - Index of Activities.
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  • 12
    Call number: ZSP-SCAR-570-4
    In: National Antarctic Research Report to SCAR, No. 4
    Type of Medium: Series available for loan
    Pages: 24 Seiten
    ISSN: 0179-0072
    Series Statement: National Antarctic Research Report to SCAR 4
    Language: English
    Note: Contents: Membership of the National Committee on Antarctic Research in the Federal Republic of Germany. - Introduction. - Stations. - I. Record of Activities (past and ongoing), April 81-October 82. - II. Planned Activities, October 82-October 83. - References.
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  • 13
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-82/43
    In: CRREL Report, 82-43
    Description / Table of Contents: The radar signatures of ice wedges and wedge-like structures have been investigated for a variety of soil conditions. The radar used for this study emitted short sinusoidal pulses of about 10-ns duration with an approximate center frequency of 150 MHz. Most of the ice wedges existed at depths of about 1 m in a variety of silty and sandy soils with both frozen and thawed active layers. The position of the wedges was usually identified from corresponding surface features. An artificial ice wedge in coarse-grained alluvium was also profiled as well as wedge-like structures of fine silt in a coarse-grained glacial outwash. All wedges and wedge-like structures produced a hyperbolic reflection profile except when an active layer of thawed, saturated silt was present which eliminated returns from the wedges. The peaks of the hyper-bolas were sometimes masked by reflections from the permafrost table or other material interfaces, and multiple hyperbolas occurred at some sites. The dielectric constant of the host medium was often calculated from the linear portions of the hyperbolas and the results were verified by laboratory time domain reflectometry measurements per-formed on field samples. In some cases, hyperbolic profiles originated at several meters depth suggesting that deep ice wedges could be detected in areas of cold permafrost.
    Type of Medium: Series available for loan
    Pages: iv, 19 Seiten , Illustrationen
    Series Statement: CRREL Report 82-43
    Language: English
    Note: CONTENTS Abstract Preface Introduction Background Objectives and procedures Equipment used Radar TDR Definitions Massive ice Results Artificial wedge: Norwich, Vermont Ice wedges in sand: Fish Creek, Alaska Ice wedges: Prudhoe Bay, Alaska Ice wedges under thawed fine-grained soils: North Slope, Alaska Wedge-like soil structures: Ft. Greely, Alaska TDR measurements Summary and concluding remarks Literature cited Appendix A: Brief discussion of dispersion
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  • 14
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-83/11
    In: CRREL Report, 83-11
    Description / Table of Contents: Investigations of ground radar performance over thawed and seasonally frozen silts, and sands and gravels containing artificial and natural reflectors were carried out in Alaska. The radar emitted 5-10 ns pulses, the center frequency of which was approximately 150 MHz. The artificial reflectors were metal sheets and discs and the natural reflectors were the groundwater table and interfaces between frozen and thawed material. The water table was profiled at three sites where the subsurface material was coarse-grained alluvium. Dielectric constants of 16 to 18 were measured for the thawed silts, 6 to 7 for the frozen silts and 3 to 9 for the sands and gravels. Signal penetration in the thawed high moisture content silts may be achieved only by use of a lower frequency radar, whereas in the sands and gravels greater depths may be detected with more sophisticated signal processing.
    Type of Medium: Series available for loan
    Pages: 16 Seiten , Illustrationen
    Series Statement: CRREL Report 83-11
    Language: English
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  • 15
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-83/17
    In: CRREL Report, 83-17
    Description / Table of Contents: A sea ice model was applied to the East Greenland Sea to examine a 60-day ice advance period beginning 1 October 1979. This investigation compares model results using driving geostrophic wind fields derived from three sources. Winds calculated from sea-level pressures obtained from the National Weather Service's operational analysis system resulted in strong velocities concentrated in a narrow band adjacent to the Greenland coast, with moderate velocities elsewhere. The model showed excessive ice transport and thickness build-ups in the coastal region. The extreme pressure gradient parallel to the coast resulted partially from a pressure reduction procedure that was applied to the terrain-following sigma coordinate system to obtain sea-level pressures. Additional sea-level pressure fields were obtained from an independent optimal interpolation analysis that merged FGGE buoys drifting in the Arctic basin with high latitude land stations and from manual digitization of the NWS hand-analyzed Northern Hemisphere Surface Charts. Modeling results using winds from both of these fields agreed favorably.
    Type of Medium: Series available for loan
    Pages: 19 Seiten , Illustrationen
    Series Statement: CRREL Report 83-17
    Language: English
    Note: CONTENTS Abstract Preface Introduction Description of study Model results The problem Conclusions Literature cited
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  • 16
    Call number: ZSP-201-83/24
    In: CRREL Report, 83-24
    Description / Table of Contents: Secondary recovery of oil at Prudhoe Bay, Alaska, will involve transporting large quantities of seawater in elevated pipelines across tundra for injection into oil-bearing rock strata. The possibility of a pipeline rupture raises questions concerning the effects of seawater on tundra vegetation and soils. To evaluate the relative sensitivities of different plant communities to seawater, eight sites representing the range of vegetation types along the pipeline route were treated with single, saturating applications of seawater during the summer of 1980. Within a month of the treatment 30 of 37 taxa of shrubs and forbs in the experimental plots developed clear symptoms of stress, while none of the 14 graminoid taxa showed apparent adverse affects. Live vascular plant cover was thus reduced by 89 and 91% in the two dry sites and by 54, 74 and 83% in the three moist sites, respectively. Live(green) bryophyte cover was markedly reduced in the moist experimental sites in 1981. Bryophytes in all but one of the wet-site experimental plots were apparently unaffected by the seawater treatment. Two species of foliose lichens treated with seawater showed marked deterioration in 1981. All other lichen taxa were apparently unaffected by the seawater treatment. The absorption and retention of salts by the soil is inversely related to the soil moisture regime. In the wet sites, conductivities approached prespill levels within about 30 days. In such sites, spills at the experimental volumes are quickly diluted and the salts flushed from the soil. In the dry sites, on the other hand, salts are retained in the soil, apparently concentrating at or near the seasonal thaw line.
    Type of Medium: Series available for loan
    Pages: 43 Seiten , Illustrationen
    Series Statement: CRREL Report 83-24
    Language: English
    Note: CONTENTS Abstract Preface Introduction Methods Site selection and preparation Prespill assessment Seawater application Postspill assessment Enzyme assay and analysis of soil flora Results and discussion Soil-solution conductivities Vascular plant response Cryptogam response Site factors and plant response Soil flora and extracellular soil enzymes Limitations of this study Summary and conclusions Literature cited Appendix: Plant taxa included in this study
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  • 17
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    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-83/29
    In: CRREL Report, 83-29
    Description / Table of Contents: A literature review indicated that the effects or permafrost on streambank erodibility and stability are not yet understood because systematic and quantitative measurements are seriously lacking. Consequently, general controversy exists as to whether perennially frozen ground inhibits lateral erosion and bankline recession, or whether it increases bank recession rates. Perennially frozen streambanks erode because of modification of the bank's thermal regime by exposure to air and water, and because of various erosional processes. Factors that determine rates and locations of erosion include physical, thermal and structural properties of bank sediments, stream hydraulics and climate. Thermal and physical modification of streambanks may also induce accelerated erosion within permafrost terrain removed from the immediate river environment. Bankline or bluffline recession rates are highly variable, ranging from less than 1 m/year to over 30 m/year and, exceptionally, to over 60 m/year. Long-term observations of the physical and thermal erosion processes and systematic ground surveys and measurements of bankline-bluffline recession rates are needed.
    Type of Medium: Series available for loan
    Pages: iv, 26 Seiten , Illustrationen
    Series Statement: CRREL Report 83-29
    Language: English
    Note: CONTENTS Abstract Preface Introduction Stream bank erosional processes Permafrost and related factors Permafrost and erosion General Erosional processes Bank zone processes Bluff zone processes Factors affecting perm afrost erodibility Exposure to currents and wind waves Texture and stratigraphy Ice content, distribution and type Slope aspect Coriolis force Timing and depth of thaw Water level and temperature Vegetation Ice and snow cover Groundwater Rates and timing of erosion and recession Overall effects of permafrost Recommendations for research Literature cited Appendix A : Processes of stream bank modifications
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  • 18
    Call number: ZSP-201-86/3
    In: CRREL Report, 86-3
    Description / Table of Contents: Experiments to study the melting of a horizontal ice sheet with a flow of water above it were conducted in a 35 m long refrigerated flume with a cross section of 1.2x1.2 m. Water depth, temperature, and velocity were varied as well as the temperature and initial surface profile of the ice sheet. The heat transfer regimes were found to consist of forced turbulent flow at high Reynolds numbers with a transition to free convection heat transfer. There was no convincing evidence of a forced laminar regime. The data were correlated for each of the regimes, with the Reynolds number, Re, or the Grashof number combined with the Reynolds number as Gr/Re to the 2.5 power used to characterize the different kinds of heat transfer. For water flowing over a horizontal ice sheet, the melting heat flux, for low flow velocities, was not found to drop below the value for the free convection case-488.5 W/sq m-as long as the water temperature exceeds 3.4 C. This is significant since the free convection melt values far exceed those for laminar forced convection. At the low flow velocities, the melting flux was not dependent upon the fluid temperature until the water temperature dropped below 3.4 C, when q sub c = 135.7 (Delta T). In general, the heat transfer was found to significantly exceed that of non-melting systems for the same regimes. This was attributed to increased free stream turbulence, thermal instability due to the density maximum of water near 4 C, and the turbulent eddies associated with the generation of a wavy ice surface during the melting.
    Type of Medium: Series available for loan
    Pages: vii, 85 Seiten , Illustrationen
    Series Statement: CRREL Report 86-3
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Non-melting heat transfer relations for horizontal surfaces Heat transfer for melting horizontal ice sheets Instrument setup, data acquisition and test procedures General Instrumentation Data acquisition Computer software Test procedures Data output from computer Equations used for data analysis Control volume and melting surface Control of variables Error analysis Experimental results and discussion Wave formation Temperature and velocity profiles in open channel flow Correlation of data Summary Literature cited Appendix A: Conversion equations for data acquisition equipment Appendix B: Computer code for data acquisition and analysis Appendix C: Typical test output Appendix D: Thermal properties of water and ice Appendix E: Error analysis Appendix F: Summary of test conditions Appendix G: Experimental data and calculated quantities, with inlet length
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  • 19
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-86/9
    In: CRREL Report, 86-9
    Description / Table of Contents: The bulk aerodynamic transfer coefficients for sensible (C sub H) and latent (C sub E) heat over snow and sea ice surfaces are necessary for accurately modeling the surface energy budget but are very difficult to measure. This report therefore presents a theory that predicts C sub H and C sub E as functions of the wind speed and a surface roughness parameter. The crux of the model is establishing the interfacial sublayer profiles of the scalars, temperature and water vapor, over aerodynamically smooth and rough surfaces. These interfacial sublayer profiles are delivered from surface-renewal model in which turbulent eddies continually sweep down to the surface, transfer scalar contaminants across the interface by molecular diffusion, and then burst away. Matching the interfacial sublayer profiles with the usual semilogarithmic inertial sublayer profiles yields the roughness lengths for temperature and water vapor. With these and a model for the drag coefficient over snow and sea ice based on actual measurements, the transfer coefficients are predicted. C sub E is always a few percent larger than C and H. Both decrease monotonically with increasing wind speed for speeds above 1 m/s, both increase at all winds speeds as the surface gets rougher. Both, nevertheless, are almost between 0.0010 and 0.0015.
    Type of Medium: Series available for loan
    Pages: vi, 26 Seiten , Illustrationen
    Series Statement: CRREL Report 86-9
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Aerodynamically rough surface Aerodynamically smooth surface Scalar transfer coefficients Conclusions Literature cited
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  • 20
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-86/8
    In: CRREL Report, 86-8
    Description / Table of Contents: In this work, numerical computations of heat transfer for freezing a shaft wall have been conducted. Both fixed mesh and deforming mesh finite-element methods are used. In the fixed mesh method, latent heat effects are accounted for through a δ function in the apparent heat capacity. In the deforming mesh method, an automatic mesh-generation technique with transfinite mappings is used, and in this method two different approaches are taken to evaluate the movement of the interface. The freeze-pipes are considered as point sources with irregular distribution. The advancement of the inner and outer boundaries of the frozen wall is found to be in agreement with the previously computed results
    Type of Medium: Series available for loan
    Pages: iii, 31 Seiten , Illustrationen
    Series Statement: CRREL Report 86-8
    Language: English
    Note: CONTENTS Abstract Preface Introduction Basic finite-element formulas Description of problem Finite-element equation-fixed mesh Finite-element equation-deforming mesh Transfinite mapping technique Computations and conclusions Literature cited Appendix A : Point heat sources Appendix B: Evaluation of the integral including latent heat (fixed mesh) Appendix C: Specification of [K] -deforming mesh Appendix D: Specifying δΤ/δn and the direction of mj for method I Appendix E: Procedures of method 2 Appendix F: Explanation of programs
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  • 21
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-84/32
    In: CRREL Report, 84-32
    Description / Table of Contents: Orwell Lake, in west-central Minnesota, is a flood-control, water-management reservoir first impounded in 1953. Subsequent erosion of the shoreline and a lack of knowledge of slope erosion processes in this region prompted this study to identify and quantify the processes there. The processes were measured at selected sites between June 1980 and June 1983. Erosion of the banks is primarily caused by three processes: rain, frost thaw, and waves. The first two processes tend to move sediment to the base of the steep slopes, forming 4 relatively gentle surface of accumulation. Wave action then tends to move this sediment into the lake. Analysis of the data collected over three years has confirmed that wave action is the dominant erosion process, providing almost 77% of the erosion during the 1981-82 study year. During the 1981 high pool level, 2,089 Mg of sediment, mostly colluvium, was removed from the lower slopes by wave action striking the 1.62 km of eroding shoreline. More than 4,300 Mg was eroded by waves accompanying the higher pool levels of 1982., During years in which the pool level does not exceed 325.5 m in elevation, the colluvium slope builds up at the expense of the steeper slope. But during successive years with higher pool levels, the resulting thin colluvium is quickly eroded. Erosion of the primary sediment, a compact till, then occurs, forming the S typical nearly vertical banks. In winter the upland surface adjacent to the lake freezes to a depth of between 1 and 2 m, depending on the surface temperature, the mow cover, and the distance from exposed banks. In late winter soil aggregates, released by the sublimation of interstitial ice within the banks, begin to accumulate at the base of the slopes, often veneering snowbanks there. Once thaw begins, slab failure of bank sediment is followed by mudflows and earthflows. Thaw failure at Orwell Lake in the winter of 1981-82 accounted for over 20% of the erosion; in the spring of 1982, 824 Mg was eroded by this process and 746 Mg the following spring. Such slope failure is most intense along north-facing banks and considerably less intense on south-facing banks, where more effective desiccation and sublimation reduce the soil moisture content. Summer rainfall is responsible for the remaining 3% of the total erosion, amounting to 102 Mg in 1981 and 208 Mg in 1982. Because the banks are steep and relatively short, rainwash is infrequent; rainsplash is the most consistent process during the summer, but the infrequent storms during which rainwash occurscause greater total erosion. Erosion by rain has increased in each of the past three summers, largely because of increased precipitation. Infrequent massive slope failures (slumps) have occurred at the east end of the lake where a buried clay rich unit is stratigraphically and topographically positioned to favor such failures. Drought years followed by heavy spring rains probably will result in additional slope failures of this type at the east end. Unless changes are made, the banks at Orwell Lake will continue to recede. Restriction of the pool level to less than 325.5-m elevation is the least expensive solution to the problem.
    Type of Medium: Series available for loan
    Pages: ix, 110 Seiten , Illustrationen
    Series Statement: CRREL Report 84-32
    Language: English
    Note: CONTENTS Abstract Preface Summary Chapter 1. Introduction Location Purpose of study Previous work Chapter 2. Methodology Geology Overland erosion Wave erosion Frost penetration and heave Thaw failure Bank recession Ground water Soil moisture Chapter 3. Results Geology Geotechnical properties Overland erosion Wave erosion Freeze-thaw phenomena Ground water fluctuations Other slope failures Chapter 4. Discussion Overland erosion Wave erosion Thaw failure Universal soil loss equation Chapter 5. Summary and conclusions Techniques Erosion processes at Orwell lake Bank recession Literature cited Appendix A1: Average cumulative change of surface at erosion stations #2-12, 1980-81 Appendix A2: Cumulative net changes at overland erosion stations #1-12, 1980-81 Appendix A3: Cumulative net changes at overland erosion stations #1 -12, 198 1-82 Appendix A4: Cumulative average erosion at overland erosion stations #1-12, 1980-81 Appendix AS: Cumulative average erosion at overland erosion stations #1-12, 1981-82 Appendix A6: Cumulative average erosion at overland erosion stations #1 -1 2A, 1982 Appendix B: Dimensions of erosion sections, Orwell Lake, Minnesota Appendix C: Piezometer installation data, Orwell Lake, Minneso
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  • 22
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-82/24
    In: CRREL Report, 82-24
    Description / Table of Contents: Velocity data derived from petroleum industry seismic records from Harrison Bay show that high-velocity material ( or = 2 km/s) interpreted to be ice-bonded permafrost is common. In the eastern part of the bay, the depth to high velocity material increases and velocity decreases in an orderly manner with increasing distance from shore until the layer is no longer apparent. The western part of the bay is less orderly, possibly reflecting a different geological and thermal history. This western part may be an inundated section of the low coastal plain characterized by the region north of Teshekpuk Lake, and could have contained deep thaw lakes, creating low velocity zones. Along some seismic lines, the high-velocity material extends approximately 25 km offshore. Two anomalies have been found which could be associated with rapidly degrading permafrost. One is strong attenuation, which was interpreted as an indication of gas in the shallow deposits. The other is the presence of considerable seismic noise, including identifiable small seismic events. The origin of this noise has not been positively established, and it is proposed that it may indicate that some movement is occurring in the sediments due to thaw.
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    Pages: 65 Seiten , Illustrationen
    Series Statement: CRREL Report 82-24
    Language: English
    Note: CONTENTS Abstract Preface Introduction Methods Reading records Refractions Reflections Rayleigh waves Spatial resolution Anomalies Results and discussion Seismic velocity distribution Attenuation Low-level natural seismicity Summary Literature cited Appendix A: Error estimates Appendix B: Velocity profiles Appendix C: Seismic cross sections
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  • 23
    Call number: ZSP-201-82/26
    In: CRREL Report, 82-26
    Description / Table of Contents: The Caribou-Poker Creeks Research Watershed is a small (101.5-sq km) drainage basin located 48 km northwest of Fairbanks, Alaska. Elevations within the watershed range from 210 to 826 m, and approximately 28% of its area is underlain by permafrost. Climatic differences between the watershed and Fairbanks are primarily due to the higher elevation of the watershed. Generally the watershed climatic sites are warmer in winter and cooler in summer than Fairbanks. Within the watershed the greatest temperature contrasts exist in winter, when the valley-bottom sites are beneath the regional air temperature inversion, and the higher sites are above it. From May through September the total precipitation averages 270 mm, 1.47 times that received at Fairbanks. The annual precipitation is about 1.7 times that of Fairbanks. The historical precipitation record at Fairbanks indicates that summer precipitation was below the long-term normal in eight of the eleven years of watershed measurements (1969-1980); no climatic extremes occurred during this period. An analysis of annual streamflow data showed an inconsistency of baseflow recessions from year to year. The runoff-rainfall ratio for individual summer storms averaged 0.35 for Caribou Creek. Comparisons of spot discharge measurements of predominantly permafrost and non-permafrost subwatersheds showed that permafrost-dominated watersheds have a much flashier response to precipitation than non-permafrost watersheds. A comparison of the annual flow distribution of the watershed indicated that Caribou Creek has lower summer and higher winter discharges per unit area than the Chena or Salcha Rivers.
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    Pages: 42 Seiten , Illustrationen
    Series Statement: CRREL Report 82-26
    Language: English
    Note: CONTENTS Abstract Preface Introduction Setting Geology and soils Vegetation Climate Air temperature Precipitation Hydrology Annual and monthly runoff Individual storms Baseflow recessions Spatial flow variability Temporal flow variability Summary and conclusions Literature cited Appendix A: Station histories
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  • 24
    Call number: ZSP-201-87/17
    In: CRREL Report, 87-17
    Description / Table of Contents: The ability to map frazil ice deposits and water channels beneath an ice-covered river in central Alaska using the magnetic induction conductivity (MI) technique has been assessed. The study was performed during the first week of March of 1986 on the Tanana River near Fairbanks and employed a commercially available instrument operating at a fixed frequency with a fixed antenna (coil) spacing and orientation. Comparisons of the MI data with theoretical models based upon physical data measured along three cross sections of the river demonstrate the sensitivity of the MI technique to frazil ice deposits. The conductivity generally derived for the frazil ice deposits encountered is very low (approx. .00063 s/m) when compared with the measured value for water (approx. 0.011 S/m), and is similar to the calculated values for gravel and sandy gravel bed sediments. In all three cross sections, maxima in the apparent conductivity profiles correlated with frazil ice deposits. Difficulties, possibly due to adverse effects of cold weather upon instrument calibration, affected the quantitative performance of the instrument on one cross section, although the interpretation of the data (locations of open channels vs frazil deposits) was qualitatively unaffected.
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    Pages: iii, 17 Seiten , Illustrationen
    Series Statement: CRREL Report 87-17
    Language: English
    Note: CONTENTS Abstract Preface Introduction Magnetic induction conductivity method Site description and survey methods Cross section field data and modeling results X6 X3A X4 Conclusions and recommendations Literature cited Appendix A: Discussion of errors Appendix B: Modeling data
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  • 25
    Call number: ZSP-201-88/1
    In: CRREL Report, 88-1
    Description / Table of Contents: The Cornish-Windsor bridge is the longest covered bridge in the United States and has significant historical value. At a large peak flow, dynamic ice breakup of the Connecticut River can threaten the bridge and cause flood damage in the town of Windsor, Vermont. Throughout the 1985-86 winter we regularly monitored ice conditions, including a midwinter dynamic ice breakup on 27 January. We conducted controlled release tests over the operating range of the turbines at Wilder Dam upstream during both open water and ice cover conditions. These data and observations were analyzed in light of more than 60 years of temperature and discharge records. Our analysis indicates that river regulation presents alternatives for ice management that would minimize the probability of bridge damage and flooding during breakup. The flow can be regulated early in the winter to promote the growth of a stable ice cover, minimizing the total ice production in the reach. In the weeks prior to breakup, sustained releases and above-freezing air temperatures cause melting, weakening and gradual breakup of the ice, greatly reducing the flooding potential. Also, it is possible to produce a controlled ice breakup prior to an imminent natural event at lower stage and discharge. All of these ice control alternatives have associated power production costs.
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    Pages: iii, 21 Seiten , Illustrationen
    Series Statement: CRREL Report 88-1
    Language: English
    Note: CONTENTS Abstract Preface Introduction Background Analysis of historical data Field observations Controlled release tests January 1986 ice breakup Connecticut River ice control Minimizing ice production Hydrothermal melting Controlled ice breakup Conclusions Literature cited Appendix A: Detailed ice breakup chronology
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  • 26
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-87/19
    In: CRREL Report, 87-19
    Description / Table of Contents: The approximate heat balance integral method (HBIM) is extended to the case of a medium with variable properties such as snow. The case of linear variation of thermal conductivity was investigated. An alternative heat balance integral method (AHBIM) was developed. Both constant surface temperature and surface heat flux were considered. A comparison was made of the temperature distribution from the HBIM, AHBIM and an analytical method for the case of constant surface temperature. In general, results agree quite well with the analytical method for small values of dimensionless time τ, but the difference becomes more pronounced as τ increases. It was found that the AHBIM with a quadratic temperature profile gave a somewhat better result, especially when the value of the dimensionless distance η is small. For a specific property function of E(η) = eη, closed form solutions were obtained. The results, when compared with those from HBIM, AHBIM and the analytical method were found to agree exceptionally well with the analytical method, especially for large values of τ.
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    Pages: iv, 26 Seiten , Illustrationen
    Series Statement: CRREL Report 87-19
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Mathematical analysis Constant surface temperature Constant surface heat flux Comparison with exact solution Alternative method Conclusions and comments Literature cited Appendix A: Derivation of equation 25 Appendix B: Derivations of equations 37 and 40 Appendix C: Derivation of equations 37a and 40
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  • 27
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-87/22
    In: CRREL Report, 87-22
    Description / Table of Contents: This review discusses problems associated with the anomalous temperature-density relations of water. It covers a) onset of convection, b) temperature structure and natural convective heat transfer, and c) laminar forced convective heat transfer in the water/ice system. The onset of convection in a water/ice system was found to dependent on thermal boundary conditions, not a constant value as in the classical fluids that have a monotonic temperature-density relationship. The water/ice system also exhibits a unique temperature distribution in the melt layer immediately after the critical Rayleigh number is exceeded and soon after it establishes a more or less constant temperature region progressively deepening as the melt layer grows. The constant temperature is approximately 3.2°C for water layers formed from above but varies for melt layers from below. The heat flux across the water/ice interface was found to be a weak power function and to increase linearly with temperature for melted layers from above and below, respectively.
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    Pages: vi, 43 Seiten , Illustrationen
    Series Statement: CRREL Report 87-22
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Analytical studies on the onset of convection in a horizontal water layer Experimental studies on the onset of convection in a circular horizontal melt layer Temperature structure and heat transfer In a horizontal layer In a circular horizontal melt layer pHeat transfer studies in nonplanar geometries Forced convective heat transfer over a melting surface Discussion and conclusions Onset of convection Temperature structure and natural convective heat transfer Laminar forced convective heat transfer Literature cited
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  • 28
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-88/14
    In: CRREL Report, 88-14
    Description / Table of Contents: An experimental study covering a mass flow rate ranging from 1.62 to 67.45 g/cm2-s and snow density varying from 0.377 to 0.472 g/cm3 has been conducted. Pressure drops ranging from 0.012 to 2.868 gf/cm2 were recorded. A plot of the friction factor fp vs Rep (defined as the classical Reynolds number Re for fluid flow through conduits) showed a good representation of all the experimental data. The least-squares analysis resulted in an expression of f sub p = 118/Rep to the 1.095 power for snow, in comparison with the expression f sub p = 64/Rep developed for fluid flow through porous media of randomly packed metallic and nonmetallic materials of spherical and nonspherical shapes.
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    Pages: iv, 18 Seiten , Illustrationen
    Series Statement: CRREL Report 88-14
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Experimental setup and procedure Experimental results Discussion and conclusions Literature cited
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  • 29
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-88/18
    In: CRREL Report, 88-18
    Description / Table of Contents: The results of a laboratory testing program, carried out to compare two independent methods for determining the unfrozen water content of soils, are described. With the time domain reflectometry method, the unfrozen water content is inferred from a calibration curve of apparent dielectric constant vs volumetric water content, determined by experiment. Previously, precise calibration of the TDR technique was hindered by the lack of a reference comparison method, which nuclear magnetic resonance now offers. This has provided a much greater scope for calibration, including a wide range of soil types and temperature (unfrozen water content). The results of the testing program yielded a relationship between dielectric constant and volumetric unfrozen water content that is largely unaffected by soil type, although a subtle but apparent dependency on the texture of the soil was noted. It is suggested that this effect originates from the lower valued dielectric constant for absorbed soil water. In spite of this, the general equation presented may be considered adequate for most practical purposes. The standard error of estimate is 0.015 cc/cc, although this may be reduced by calibrating for individual soils. Brief guidelines on system and probe design are offered to help ensure that use of the TDR method will give results consistent with the relationship presented.
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    Pages: ii, 16 Seiten , Illustrationen
    Series Statement: CRREL Report 88-18
    Language: English
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  • 30
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-83/4
    In: CRREL Report, 83-4
    Description / Table of Contents: Measurements and analysis of seasonal ice growth and decay on Post Pond, New Hampshire, for the period 1973-1982 are presented. Observations included ice thickness measurements, examination of the various ice types contributing to the ice cover, and measurements of meteorological parameters for correlation with and modeling of the ice growth process. The overall nature of ice growth and decay (ice loss) on the Post Pond has been ascertained, the seasonal variability in the timing of freeze-up and ice-out and the duration of the ice cover have been determined, and the relationship of ice growth to freezing-degree-day (deg C) records evaluated on the basis of a Stefan conduction equation modified to deal with ice sheets covered with or free of snow. Ice growth occurs predominantly by the direct freezing of lake water, but snow ice may compose as much as 50% of the ice cover in winters with higher than average snowfall. Freeze-up leading to the establishment of a stable ice cover occurs during the 4-week period from the end of November to the end of December. Maximum seasonal ice thicknesses were from 45 to 67 cm and are generally attained during the first two weeks of March; ice-out, marking the final disappearance of ice from Post Pond, usually occurs by the third week of April. The overall rate of the ice loss is three to four times that of ice growth, and is dominated initially by melting from the top. As much as 50% of the ice may be lost in this way before the onset of any bottom melting. Final dissipation of the ice cover is usually expedited by candling resulting from preferential melting and disintegration of the ice at crystal boundaries.
    Type of Medium: Series available for loan
    Pages: iv, 30 Seiten , Illustrationen
    Series Statement: CRREL Report 83-4
    Language: English
    Note: CONTENTS Abstract Preface Introduction Location of study Study methods Ice thickness Ice-cover composition Surface air temperatures Freeze-up and ice-out characteristics Results and discussion Ice-growth record Freezing-degree-day records Ice-growth predictions Summary and conclusions Literature cited Appendix A: Ice-growth records Appendix B: Measured and computed ice-growth curves
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  • 31
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-84/17
    In: CRREL Report, 84-17
    Description / Table of Contents: VHF-band radiowave short pulses were transmitted within the permafrost tunnel at Fox, Alaska, over distances between 2.2 and 10.5 m. The propagation medium was a frozen silt containing both disseminated and massive ice with temperatures varying from -7°C near the transmitter to probably -2 C near the center of the tunnel overburden. The short pulses underwent practically no dispersion in the coldest zones but did disperse and refract through the warmer overburden, as suggested by calculations of the effective dielectric constant. Most significantly the measured frequency content decreased as the effective dielectric constant increased. The results indicate that deep, cross-borehole pulse transmissions over distances greater than 10 m might be possible, especially when the ground is no warmer than -4°C. The information thus pined could be used for identifying major subsurface variations, including ground ice features.
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    Pages: ii, 14 Seiten , Illustrationen
    Series Statement: CRREL Report 84-17
    Language: English
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  • 32
    Call number: ZSP-201-84/16
    In: CRREL Report, 84-16
    Description / Table of Contents: Phase composition curves are presented for a typical saline silt from Lanzhou, P.R.C., and compared to some silts from Alaska. The unfrozen water content of the Chinese silt is much higher than that of the Alaskan silts due to the large amount of soluble salts present in the silts from China, which are not present in silt from interior Alaska. When the salt is removed, the unfrozen water content is then similar for both the Chinese and Alaskan silt. Here we introduce a technique for correcting the unfrozen water content of partially frozen soils due to high salt concentrations. We calculate the equivalent molality of the salts in the unfrozen water at various temperatures from a measurement of the electrical conductivity of the extract from saturated paste.
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    Pages: iii, 25 Seiten , Illustrationen
    Series Statement: CRREL Report 84-16
    Language: English
    Note: Contents Abstract Preface Introduction Background Materials Sample preparation Nuclear magnetic resonance Specific surface area Electrical conductivity Results and discussion Summary Literature cited Appendix A: Unfrozen water content vs temperature data for Lanzhou silt
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  • 33
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-84/11
    In: CRREL Report, 84-11
    Description / Table of Contents: Data obtained from two sets of data buoys either air-dropped or deployed by ship onto the Weddell Sea pack ice during the period from Dec 1978 to Nov 1980 are presented. The buoy data include position, pressure and temperature information and to date represent the most complete combined weather and pack ice drift records for the ice-covered Southern Ocean regions. The buoys tended to drift north initially and then to turn east generally between latitudes 62°S and 64°S. Buoy 1433 turned east farther south at approximately 67°S but at about the same time as buoy 0527, implying that the westerly wind belt was farther south than usual in 1979. The range of air pressures-from about 950 mb to about 1020 mb is typical of the circumpolar low pressure trough in the Southern Hemisphere. All buoys were equipped with an internal or compartment temperature sensor. The 1980 buoys also contained an external air temperature sensor in a ventilated, shielded can at 1-m height. Although differences of 10°C or more between recorded air and compartment temperatures are common, the correlation between the two measured temperatures is generally very good. The compartment temperatures are higher probably because the buoy is radiationally heated. We found that subtracting 3°C from the average daily compartment temperature yielded a good estimate of the average air temperature for any given day. This technique can be used to construct average daily air temperature records for the 1979 buoys which only contained the internal or compartment temperature sensor.
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    Pages: v, 21 Seiten , Illustrationen
    Series Statement: CRREL Report 84-11
    Language: English
    Note: CONTENTS Abstract Preface Introduction Methods and instrumentation Results Drift tracks Pressure data Temperature data Discussion Conclusions Literature cited
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  • 34
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-88/11
    In: CRREL Report, 88-11
    Description / Table of Contents: This study assesses the effects of atmospheric icing on broadcast transmission reflections on two mountains- Mount Mansfield in northern Vermont and Mount Washington in New Hampshire. Experience and theory suggest that antenna ice accretions produce large signal reflections. Correlations between reflection coefficients and ice accretions on Rosemount ice detectors adjacent to antennas were low and occasionally negative. The unexpected correlations may be due to factors not measured, such as antenna tuning, ice type and ice location on the antenna system. Other confounding factors may include ice detector performance and methods used to compute antenna ice accretions from the ice detectors.
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    Pages: iii, 19 Seiten , Illustrationen
    Series Statement: CRREL Report 88-11
    Language: English
    Note: CONTENTS Abstract Preface Introduction Data sources Study location and icing conditions Icing data Antenna reflection data Data preparation Analyses Conclusions Literature cited
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  • 35
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    Call number: ZSP-201-88/13
    In: CRREL Report, 88-13
    Description / Table of Contents: In many sea ice engineering problems the ice sheet has been assumed to be a homogeneous plate whose mechanical properties are estimated from the bulk salinity and average temperature of the ice sheet. Typically no regard has been given to the vertical variation of ice properties in the ice sheet or to the time of ice formation. This paper first reviews some of the mechanical properties of sea ice, including the ice tensile, flexural and shear strengths, as well as the ice modulus. Equations for these properties are given as functions of the ice brine volume, which can be determined from the ice salinity and temperature. Next a numerical, finite difference model is developed to predict the salinity and temperature profiles of a growing ice sheet. In this model ice temperatures are calculated by performing an energy balance of the heat fluxes at the ice surface. The conductive heat flux is used to calculate the rate of ice growth and ice thickness by applying the Stefan ice growth equation. Ice salinities are determined by considering the amount of initial salt entrapment at the ice/water interface and the subsequent brine drainage due to brine expulsion and gravity drainage. Ice salinity and temperature profiles are generated using climatological data for the Central Arctic basin. The predicted salinity and temperature profiles are combined with the mechanical property data to provide mechanical property profiles for first-year sea ice of different thicknesses, grown at different times of the winter. The predicted profiles give composite plate properties that are significantly different from bulk properties obtained by assuming homogeneous plates. In addition the failure strength profiles give maximum strength in the interior of the sheet as contrasted with the usual assumption of maximum strength at the cold, upper ice surface. Surprisingly the mechanical property profiles are only a function of the ice thickness, independent of the time of ice formation.
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    Pages: v, 63 Seiten , Illustrationen
    Series Statement: CRREL Report 88-13
    Language: English
    Note: CONTENTS Abstract Preface Introduction Structure Composition Mechanical properties Strength Elastic constants The temperature-salinity model Temperature profiles Salinity profiles Composite plate properties Results Conclusions Literature cited Appendix A: Details of the equations for ice surface temperature and conductive heat flux Appendix B: Calculated profile and bulk properties of an ice sheet of varying thickness Appendix C: Calculated profile and bulk properties of 30- and 91-cm-thick ice sheets
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  • 36
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    Call number: ZSP-201-88/16
    In: CRREL Report, 88-16
    Description / Table of Contents: Unfrozen water content as a function of temperature was measured in the laboratory using nuclear magnetic resonance (NMR) for a Windsor sandy loam soil. The data were related to previously measured soil moisture retention data through the modified Clapeyron equation with suitable adjustment for surface tension. The results show the usefulness of extending the soil freezing curve to temperatures only slightly below freezing and the soil water curve to very great suction.
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    Pages: iii, 42 Seiten , Illustrationen
    Series Statement: CRREL Report 88-16
    Language: English
    Note: CONTENTS Abstract Preface Introduction Soil variable ø SWC and SFC similarity Mathematical representation of SWC and SFC data NMR measurement of unfrozen water content Characterization of SWC Discussion Conclusions Literature cited Appendix A: Soil freezing curve data Appendix B: Error analysis Appendix C: Soil water curve data
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  • 37
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-89/2
    In: CRREL Report, 89-2
    Description / Table of Contents: A brash ice jam in the South Channel of the St. Clair River was profiled in February 1987 using a helicopter-borne short-pulse radar operating in the UHF band near 500 MHz. During the same time, measurements of the brash ice depth and water temperature were made from a Coast Guard icebreaker. The returned radar pulses consisted of a strong coherent reflection from the water surface, preceded (and followed) by incoherent returns from the brash ice. The measured waveform time delays were then converted to mean freeboard height of the brash ice pieces above the water surface. Given the mean freeboard height, an estimate of the total brash ice thickness was made. This estimate was greater than the range of the direct shipboard measurements. The difference is believed due to differences between ice porosity above and below the water line, to melting within the ice and to partial submergence of some of the surface pieces. It is concluded that this technique could be used for mapping relative brash ice depth if the complexities of automating waveform analysis could be overcome.
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    Pages: iv, 25 Seiten , Illustrationen
    Series Statement: CRREL Report 89-2
    Language: English
    Note: CONTENTS Abstract Preface Introduction Objectives and procedures Equipment Radar Brash ice probe Temperature measurements St. Clair River ice conditions Results and discussion Thickness and temperature Size distribution Radar survey Discussion of errors Porosity Phase state of the ice Partial submergence of individual pieces Spectra of reflected energy Conclusions and recommendations Literature cited Appendix A: Laboratory verification of surface scattering from a simulated ice jam Appendix B: Display of digitized and processed data
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  • 38
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-80/18
    In: CRREL Report, 80-18
    Description / Table of Contents: The use of ice as a structural material is common practice for certain applications in cold regions. Techniques such as surface flooding or water spraying are used to accelerate ice growth rates, thereby lengthening the winter construction season. This report examines the heat and mass transfer rates from freely falling water drops in cold air. Design equations which predict the amount of supercooling of the drops as a function of outdoor ambient temperature, drop size and distance of fall are given
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    Pages: v, 14 Seiten , Illustrationen
    Series Statement: CRREL Report 80-18
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Velocity problem Heat and mass transfer problem - A single drop Heat and mass transfer - A system of drops Literature cited Appendix A: FORTRAN IV program to calculate final drop temperature, air temperatureand humidity
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  • 39
    Call number: ZSP-201-80/19
    In: CRREL Report, 80-19
    Description / Table of Contents: During the period 1975-1978 the Federal Highway Administration sponsored a series of environmental engineering in­vestigations along the Yukon River to Prudhoe Bay Haul Road. In 1976 the Department of Energy joined these in­vestigations with a series of ecological projects which continue to the present. Both agencies research efforts were con­ducted on a cooperative basis with CRREL’s in-house research program. The objectives of the research focused on 1) an evaluation of the performance of the road, 2) an assessment of changes in the environment associated with the road, 3) documentation of flora and vegetation along the 577-km-long transect, 4) methodologies for revegetation and restoration, and 5) an assessment of biological parameters as indicators of environmental integrity. In support of these objectives, specific studies were undertaken that investigated the climate along the road, thaw and subsidence beneath and adjacent to the road, drainage and side slope performance, distribution and properties of road dust, vegetation distribution, vegetation disturbance and recovery, occurrence of weeds and weedy species, erosion and its control, revegetation and restoration, and construction of the fuel gas line. This report presents background, information on the region, detailed results of the road thaw subsidence and dust investigations, and summaries of revegetation, fuel gas line, vegetation distribution, soil, and weed studies.
    Type of Medium: Series available for loan
    Pages: xv, 187 Seiten , Illustrationen
    Series Statement: CRREL Report 80-19
    Language: English
    Note: CONTENTS Abstract Preface Summary Introduction Chapter 1. The road and its environment Introduction General physiography Regional climate Surficial and bedrock geology Permafrost and ground ice General biota Vegetation Floristic survey Vegetation mapping Soils and mapping Chapter 2. Roadbed performance and associated investigations Roadbed investigations Roadbed performance Performance of drainage features Performance of sideslopes Conclusions from road, drainage and sideslope performance studies Fuel gas line construction Chapter 3. Distribution and properties of road dust along the northern portion of the Haul Road Introduction Methods Results of wind direction and velocity measurements Dust load and distribution Particle size analyses of dust Chemical composition properties of dust and related samples Soil cation composition Dust impacts on vegetation Discussion and conclusions Chapter 4. Revegetation and restoration investigations Introduction Revegetation approaches Alyeska erosion control and revegetation program Weeds and weedy plants Performance of revegetation Alyeska willow cutting program CRREL restoration experiments Conclusions Revegetation recommendations General report recommendations Literature cited Appendix A: General environmental guidelines applicable to subarctic and arctic road construction Appendix B: University-based studies along the Yukon River-Prudhoe Bay Haul Road Appendix C: CRREL maps of Haul Road showing locations of all study Sites Appendix D: Additional Haul Road cross-sectional profiles Appendix E: Clay mineralogy of road-related materials Appendix F: List of reports in the Joint State/Federal Fish and Wildlife Ad­visory Team series
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  • 40
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-80/17
    In: CRREL Report, 80-17
    Description / Table of Contents: Construction pads made of snow were used to build two sections of the Trans Alaska Pipeline and a small gas pipeline during the winter of 1975-76. Construction during the winter has become increasingly common in the Arctic. Surface travel and the use of heavy construction equipment on the unprotected tundra have been severely restricted, even during the winter, so the use of temporary winter roads and construction pads built of snow and ice has been advocated and is being adopted. The three snow construction pads mentioned above were the first snow roads and construction pads used on a large scale in Alaska. Snow roads and construction pads have two objectives: to protect the underlying vegetation and upper layers of the ground, and to provide a hard, smooth surface for travel and the operation of equipment. Several types have been built, and a brief discussion is given of their history and classification systems. The three snow construction pads used in construction of the Trans-Alaska Pipeline and the small gas pipeline in 1975-76 were visited and observed while in use. The Globe Creek snow pad, about 50 miles north of Fairbanks, was built primarily of manufactured snow hauled to the site and watered. With very high densities this pad withstood heavy traffic and use by heavy construction equipment except on one steep slope. There, the use of tracked vehicles and vehicles without front wheel drive disaggregated the snow on and near the surface so that vehicles without front wheel drive were unable to climb the hill. The Toolik snow pad, just north of the Brooks Range, was built of compacted snow and proved capable of supporting the heaviest traffic and construction equipment. The fuel gasline snow pad ran from the northern Brooks Range to the Arctic Coast and also proved capable of supporting the necessary traffic. Both the Toolik snow pad and the fuel gasline snow pad failed in very early May because of unseasonably warm and clear weather before the associated construction projects were completed. However, the three snow pads must be considered successful. Common problems were the lack of snow, slopes, unseasonably warm spring weather, and inexperience on the part of contractors and construction personnel.
    Type of Medium: Series available for loan
    Pages: v, 28 Seiten , Illustrationen
    Series Statement: CRREL Report 80-17
    Language: English
    Note: CONTENTS Abstract Preface Introduction History of snow and ice roads Classification of snow and ice roads Snow pads used by Alyeska during the winter of 1975-1976 The Globe Creek snow pad The Toolik snow pad The gasline snow pad Summary and conclusions Literature cited
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  • 41
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-81/19
    In: CRREL Report, 81-19
    Description / Table of Contents: Field observations support the interpretation that differences in the strength of radar returns from the ice covers of lakes on the North Slope of Alaska can be used to determine where the lake is frozen completely to the bottom. An ice/frozen soil interface is indicated by a weak return and an ice/ water interface by a strong return. The immediate value of this result is that SLAR (side-looking airborne radar) imagery can now be used to prepare maps of large areas of the North Slope showing where the lakes are shallower or deeper than 1.7m (the approximate draft of the lake ice at the time of the SLAR flights). The bathymetry of these shallow lakes is largely unknown and is not obvious from their sizes or outlines. Such information could be very useful, for example in finding suitable year-round water supplies.
    Type of Medium: Series available for loan
    Pages: iii, 17 Seiten , Illustrationen
    Series Statement: CRREL Report 81-19
    Language: English
    Note: CONTENTS Abstract Preface Introduction The experiment Results Maps of completely frozen North Slope lakes Literature cited
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  • 42
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-81/20
    In: CRREL Report, 81-20
    Description / Table of Contents: A historical review of research is presented to establish the state- of-the-art for analyzing the behavior of vehicles in shallow snow. From this review, the most comprehensive and promising model is put together to establish a first-cut performance prediction model for vehicles operating in shallow snow, slush, ice and thawing soils.
    Type of Medium: Series available for loan
    Pages: iv, 21 Seiten , Illustrationen
    Series Statement: CRREL Report 81-20
    Language: English
    Note: CONTENTS Abstract Preface List of symbols Introduction Historical review Model selection Traction Resistance Slush and thawing soils Ice, hard-packed snow, packed snow River and lake ice Model use Conclusions Literature cited
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  • 43
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-81/18
    In: CRREL Report, 81-18
    Description / Table of Contents: During the growing seasons of 1977, 1978, and 1979, revegetation techniques were studied on the Chena River Lakes Project, a flood control dam and levee near Fairbanks, Alaska, to find an optimal treatment for establishing permanent vegetation cover on the gravel structures. The treatments tested on plots at the dam andor levee involved three main variables 1 vegetation grass and clover seed andor willow cuttings, 2 mulch, mulch blanket, andor sludge, and 3 substrate gravel or fine-grained soil over the gravel base. The mulches were hay, wood-cellulose-fiber, peat moss, and Conwed Hydro Mulch 2000, which is a wood-cellulose-fiber mulch with a polysaccharide tackifier. A constant rate of fertilizer was applied to all plots except the control. A section of each plot was refertilized again in their third growing season to compare annual and biannual fertilization. The high fertilization rate produced above-average growth. Fescue, brome, and foxtail were the most productive species on the dam, while alsike cover was the most productive on the wetter levee site. When grass seed and willow cuttings were planted at the same time, willow survival and growth were reduced. Fertilization is required for at least two years to produce an acceptable permanent vegetation cover, although fine- grained soil or sludge reduces the amount of fertilizer needed in the second year. Third-year fertilization may not be necessary since the benefits of the second fertilization continue for at least two years. A sludge treatment refertilized during its second growing season produces the highest biomass recorded in this study.
    Type of Medium: Series available for loan
    Pages: ix, 59 Seiten , Illustrationen
    Series Statement: CRREL Report 81-18
    Language: English
    Note: CONTENTS Abstract Preface Abbreviations Conversion factors Summary Introduction Background Site characterization Climate Purpose Materials and methods General Moose Creek Dam site Tanana Levee site Sampling and measurement Abiotic controls on vegetation Meteorological data Soil moisture as a limiting factor Soil chemical analysis Vegetation growth and survival Moose Creek Dam site Tanana Levee site Biomass by species Roof penetration Seedling density of invading woody species Weeds Supplemental observations Sediment loss Sludge and runoff-water composition Cost analysis Conclusions Literature cited Appendix A: 1977 grass growth on 1977 dam treatments Appendix B: 1978 grass growth on 1977 dam treatments Appendix C: 1979 grass growth on 1977 dam treatments Appendix D: Grass growth on 1978 dam treatments Appendix E: 1977, 1978, and 1979 survival of willow treatments Appendix F: Grass growth on Tanana levee treatments Appendix C: Chemical analysis of sludge and runoff water
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  • 44
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-81/21
    In: CRREL Report, 81-21
    Description / Table of Contents: The reflection of solar radiation by a snow cover in situ and the apparent influence of selected substrates were examined in wavelength bands centered at 0.81, 1.04, 1.10, 1.30, 1.50 and 1.80 micrometers. Substrates included winter wheat, timothy, corn, alfalfa, grass, concrete and subsurface layers of 'crusty' snow and ice. Reasonable qualitative agreement between measurements and theoretical predictions was demonstrated, with indications of quantitative agreement in the definition of a 'semi-infinite depth' of snow cover. It was concluded that ultimate quantitative agreement between theory and measurement will require that an 'optically effective grain size' be defined in terms of physically measuarable dimensions or meteorologically predictable characteristics of the ice crystals composing the snowpack.
    Type of Medium: Series available for loan
    Pages: iii, 17 Seiten , Illustrationen
    Series Statement: CRREL Report 81-21
    Language: English
    Note: CONTENTS Abstract Preface Introduction Experimental method Substrate preparation Experimental configuration Radiometric measurements Snow characterization Reflectance standards Data analysis Reflectance measurements Snow replica analysis Discussion of results Comparative reflectance of various substrates under snow Ablation of a snow cover Reflectance from a very light, fresh snow cover Measurements at angles other than vertical Reflectance from substrates Concluding observations Literature cited
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  • 45
    Call number: ZSP-201-80/5
    In: CRREL Report, 80-5
    Description / Table of Contents: This research comprised laboratory testing to determine the properties of asphalt-aggregate mixtures containing three grades of asphalt cements, and analyses to project the performance of pavements containing each of the asphalts, in resisting thermally induced distress and traffic-associated distress. From the results it is concluded that only the softest asphalt cement tested (AC 2.5) would perform satisfactorily in a cold climatic zone. The moderately soft (AC 5) and moderately hard (AC 20) asphalt cements showed little susceptibility to thermal cracking in a moderate and a warm climatic zone, respectively. The AC 2.5 and AC 5 asphalts are not recommended for use in warm climates, however, owing to increased susceptibility to rutting under traffic.
    Type of Medium: Series available for loan
    Pages: vi, 55 Seiten , Illustrationen
    Series Statement: CRREL Report 80-5
    Language: English
    Note: CONTENTS Abstract Preface Introduction Research setting Objectives Materials, mixture designs, and tests Materials Mixture design tests Brazil test Resilient modulus test Data analysis Marshall tests Asphalt grade Compactive effort Aggregate type Data analysis Brazil tests Indirect tensile strength Tensile strain Vertical deformation Summary of Brazil test results Data analysis-resilIient modulus. Comparison of mixture susceptibility to temperature cracking General asphalt concrete stiffness Thermal cracking. Influence of asphalt cement properties Summary Comparison of mixture susceptibility to traftic-load-associated distress Stress/strain analysis Fatigue damage analysis Rutting analysis Strength correlations Marshall stability and indirect tensile strength Indirect tensile strength and resilient modulus Summary Summary and conclusions Recapitulation of investigations Summary of results Conclusions Literature cited Appendix A: Asphalt adggregate mixture properties by Marshall method Appendix B: Equations for calculating specimen properties from Brazil tests Appendix C: Calculated displacements, strains and stresses
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  • 46
    Call number: ZSP-201-80/4
    In: CRREL Report, 80-4
    Description / Table of Contents: The primary objectives of this study were to 1) prepare a map from Landsat imagery of the Upper Susitna River Basin drainage network, lakes, glaciers and snowfields, 2) identify possible faults and lineaments within the upper basin and within a 100-km radius of the proposed Devil Canyon and Watana dam sites as observed on Landsat imagery, and 3) prepare a Landsat-derived map showing the distribution of surficial geologic materials and poorly drained areas. The EROS Digital Image Enhancement System (EDIES) provided computer- enhanced images of Landsat-1 scene 5470-19560. The EDIES false color composite of this scene was used as the base for mapping drainage network, lakes, glaciers and snowfields, six surficial geologic materials units and poorly drained areas. We used some single-band and other color composites of Landsat images during interpretation. All the above maps were prepared by photointerpretation of Landsat images without using computer analysis, aerial photographs, field data, or published reports. These other data sources were used only after the mapping was completed to compare and verify the information interpreted and delineations mapped from the Landsat images. Four Landsat-1 MSS band 7 winter scenes were used in the photomosaic prepared for the lineament mapping. We mapped only those lineaments related to reported regional tectonics, although there were many more lineaments evident on the Landsat photomosaic.
    Type of Medium: Series available for loan
    Pages: iii, 41 Seiten , Illustrationen
    Series Statement: CRREL Report 80-4
    Language: English
    Note: CONTENTS Abstract Preface Summary Objectives Conclusions Introduction Background Previous cooperative investigations Project rationale and coordination Approach Landsat imagery Interpretation techniques Part I. Use of Landsat imagery in mapping the drainage network, lakes, glaciers and snowfields (Lawrence W. Gatto) Objective Methods Results Conclusions Part II. Use of Landsat imagery in mapping and evaluating geologiclineaments and possible faults (Carolyn J. Merry) Objective Geologic structure Methods Results Conclusions Part Ill. Use of Landsat imagery in mapping surficial materials Section A. Landsat mapping (Harlan L. McKim) Objective Methods Results Section B. Field evaluation (Daniel E. Lawson) Objectives Methods Results Discussion Section C. Conclusions (Daniel E. Lawson and Harlan L. McKim) Literature cited Glossary
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  • 47
    Call number: ZSP-201-81/15
    In: CRREL Report, 81-15
    Description / Table of Contents: This report analyzes the results of a field study previously reported by Scrivner et al. (1969) for the National Cooperative Highway Research Program. These authors studied the seasonal pavement deflection characteristics of 24 test sites on roads in service in regions with freezing indexes ranging from 100 F-days to 2100 F-days. They used the Dynaflect cyclic pavement loading device to determine the pavement system response. Of specific interest to my analysis was the increased pavement deflection after freezing and thawing and the time to recovery of normal deflection characteristics. These characteristics were related to soil and climatic factors using statistical techniques. The most significant observations of this statistical analysis are: (1) that the freezing index is not a significant parameter in determining the percent increase in pavement deflection during thawing, and (2) that the recovery time is inversely proportional to the depth of freezing. As was expected, the most significant variable affecting the increase in pavement deflection was the frost susceptibility classification. This observation reinforces the necessity for careful selection of soil materials used in pavement systems.
    Type of Medium: Series available for loan
    Pages: v, 10 Seiten , Ilustrationen
    Series Statement: CRREL Report 81-15
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Description of test site Test results Method of analysis Results of analysis Change in resilient deflection due to thawing, A Recovery time after onset of thawing, t20 Discussion of results Change in resilient deflection due to thawing, A. Recovery time after thawing, t20 Conclusions Literature cited ILLUSTRATIONS Figure Pavement deflection and frost penetration vs time Data points and regression line for A and t2 0 versus F Data points and regression line for A and t2 0 versus W Data points and regression line for A and t2 0 versus I Data points and regression line for A and t20 versus N Data points and regression line for A and t20 versus D Data points and regression line for t20 versus A Permeability vs void ratio for the Toledo Penn 7 material TABLES Properties of test sections Test results from Scrivner et al Results of regression analysis
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  • 48
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-81/16
    In: CRREL Report, 81-16
    Description / Table of Contents: An air-transportable shelter designed and built at CRREL for use in cold regions underwent testing in Hanover, New Hampshire, and Ft. Greely, Alaska. The shelter demonstrated some of its capabilities for mobility by being towed for more than 60 miles behind various vehicles and by being transported on a C-130 cargo airplane, a CH-47 helicopter, and a trailer truck. The shelter proved to be very easy for a crew of two to four to set up in all weather conditions including -40 F cold. However, the gasoline-powered generator, which was a source for space heat as well as electricity, functioned very poorly. Overall, the prototype successfully demonstrated qualities of self-reliance, ease of operation and thermal efficiency.
    Type of Medium: Series available for loan
    Pages: v, 20 Seiten , Illustrationen
    Series Statement: CRREL Report 81-16
    Language: English
    Note: CONTENTS Abstract Preface Metric conversion factors Summary Introduction Description of shelter Test procedures and results Mobility Ease of erecting and striking Therinal efficiency and performance Heat output Electrical system Habitation Safety features Water system Shelter reliability Structure Performance of other shelters Conclusions Future studies Literature cited
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  • 49
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-81/17
    In: CRREL Report, 81-17
    Description / Table of Contents: Environmental conditions are described for the continental shelf of the western Arctic, and for the shelf of Labrador and Newfoundland. Special emphasis is given to the gouging of bottom sediments by ice pressure ridges and icebergs, and an approach to systematic risk analysis is outlined. Protection os subsea pipelines and cables by trenching and direct embedment is discussed, touching on burial depth, degree of protection, and environmental impact. Conventional land techniques can be adapted for trenching across the beach and through the shallows, but in deeper water special equipment is required. The devices discussed include hydraulic dredges, submarine dredges, plows, rippers, water jets, disc saws and wheel ditchers, ladder trenchers and chain saws, routers and slot millers, ladder dredges, vibratory and percussive machines, and blasting systems. Consideration is given to the relative merits of working with seabed vehicles, or alternatively with direct surface support from vessels or from the sea ice
    Type of Medium: Series available for loan
    Pages: 38 Seiten , Illustrationen
    Series Statement: CRREL Report 81-17
    Language: English
    Note: CONTENTS Abstract Preface Introduction The western Arctic of North America The continental shelf of Newfoundland and Labrador Burial depth for pipes and cables Degree of protection offered by burial Environmental impact Trenching the beach and the shallows in the western Arctic Trenching beyond the shallows Suction, or hydraulic, dredging Bottom-t raveling cutterhead dredges Plows Rippers Water jets Subsea disc saws and wheel ditchers Subsea ladder trenchers and chain saws Subsea routers and slot millers Bucket ladder trenchers Vibratory and percussive devices Hard rock excavation under water Control and monitoring of subsea machines Vessels and vehicles Trenching from the sea ice Costs of subsea trenching Reference Appendix: Description of waters off Alaska and Newfoundland
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  • 50
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-81/3
    In: CRREL Report, 81- 3
    Description / Table of Contents: Abstract: A 1:24 scale hydraulic model study of water intake under frazil ice conditions is presented. The intake, located 9 m below the surface of the St. Lawrence River in Massena, New York,has a through flow of 0.14 m^3/s. The model study, conducted in the refrigerated flume facility of the U.S. Army Cold Regions Research and Engineering Laboratory, investigated methods of minimizing the frazil ice blockage on the intake. Two protective structures were modeled and the relative benefits of each are presented. The additional cross-sectional area provided by the protective structures lowered the vertical velocity component of the intake water to 0.0027 m/s. At this velocity the buoyant force acting on the frazil ice particle is larger than the downward drag force, causing the particle to rise. The results demonstrate that under certain low flow conditions a protective structure can minimize frazil ice blockage problems.
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    Pages: 11 Seiten , Illustrationen
    Series Statement: CRREL Report 81-03
    Language: English
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  • 51
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-81/2
    In: CRREL Report, 81-2
    Description / Table of Contents: Abstract: Many hyperbolic reflections have been observed on marine seismic records obtained during oil exploration in the Beaufort Sea, and on USGS seismic sub-bottom profiles from the Prudhoe Bay vicinity. A hyperbolic projection system was designed to rapidly measure seismic velocities from the curves on the records. The velocities observed were approximately the velocity of sound in water. The hyperbolic signals also showed dispersion properties similar to acoustic normal modes in shallow water. These observations indicate that the signals responsible for the hyperbolic reflections propagate as normal modes within the water layer, with very limited penetration of the seabed. Determinations of the dominant frequency of these signals indicate that the penetration into the seabed has a characteristic attenuation depth (skin depth) of about 1.5 m for the sub-bottom profiles and 12 m for the marine records. It therefore appears that some hyperbolic reflections may be generated by variations in materials that occur near the seabed. There is some evidence of linearity of the anomalies, possibly related to sediment-filled or open ice gouges, or other changes in material properties at shallow depths.
    Type of Medium: Series available for loan
    Pages: iv, 16 Seiten , Illustrationen
    Series Statement: CRREL Report 81-2
    Language: English
    Note: CONTENTS Abstract Preface Introduction Methods of analysis Marine seismic records Seismic sub-bottom profiles Results and discussion Distribution of hyperbolic reflections Hyperbolas on oil exploration records Hyperbolas on sub-bottom profiles Conclusions Literature cited Appendix A: Hyperbola projector
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  • 52
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-81/12
    In: CRREL Report, 81-12
    Description / Table of Contents: Revegetation techniques along the trans-Alaska pipeline as employed by Alyeska Pipeline Service Company during the 1975-1978 summers were observed. Objectives included determining the success of treatments, identifying problem areas, and noticing long-term implications. Observations and photographs at 60 sites located along the trans-Alaska pipeline indicated frequent occurrence of successful revegetation as well as frequent problems, such as erosion, slope instability, poor scheduling of seed application, occurrence of weed species, failure to optimally reuse topsoil and fine-grained soil, and low rates of native species reinvation. Alyeska's visual impact engineering was observed to be very successful, as shown by high first-season survival. However, a related program for establishing willow cuttings was unsuccessful in 1977 but appeared very promising in 1978 largely due to improved management and more favorable growing conditions. Terrain disturbances due to the construction of the fuel gas line, snowpads, and oil spills were examined to identify and describe related environmental impacts on natural vegetation. Proper construction and use of snowpads minimized the extent and severity of disturbance. Crude oil spills, although damaging to vegetation did not cause total kill of vegetation, and certain types of spills may have only short-term effects. Results of restoration research by CRREL along the trans-Alaska pipeline are discussed.
    Type of Medium: Series available for loan
    Pages: 115 Seiten , Illustrationen
    Series Statement: CRREL Report 81-12
    Language: English
    Note: CONTENTS Abstract Preface Summary Introduction Revegetation procedures 1975-1978 construction seasons Willow cutting program Visual impact engineering program Selected terrain disturbances Fuel gas line and snowpads Island Lake and oil line snowpads Oil spills and revegetation CRREL restoration sites Conclusions Recommendations Literature cited Appendix A: List of sites observed during 1975 Appendix B: Annotated photographs of permanent revegetation observation sites-1975-1978 Appendix C: Photographic record of fuel gas line observation sites
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  • 53
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-81/13
    In: CRREL Report, 81-13
    Description / Table of Contents: Electrical properties of frozen ground were measured using radio frequency interferometry (RFI) in the very high frequency (VHF) radiowave band. Ice-rich organic silts and sands and gravels of variable ice content were investigated during early April of both 1979 and 1980. Frequencies between 10 and 150 MHz were used with best results obtained between 40 and 100 MHz. Surface impedance and magnetic induction techniques were also used to obtain an independent measure of low frequency resistivity and to obtain a separate control on vertical inhomogeneity. Soil samples were tested for organic and water content. The dielectric constants determined for the ice-rich organic silts ranged from 4.0 to 5.5 while those for the sands and gravels were about 5.1. Dielectric loss was due to d.c. conduction and was very low for the silts but significant for the sands and gravels. The higher values for the sands and gravels were most likely due to the higher concentrations of salt that are reported to exist in the old beach ridges in this region. All the RFI measurements are believed to be indicative of only the first few meters of the ground although the radiowaves could penetrate to tens of meters.
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    Pages: iv, 18 Seiten , Illustrationen
    Series Statement: CRREL Report 81-13
    Language: English
    Note: CONTENTS Abstract Preface Introduction Background Objectives and procedures Theory and instrumentation Radio frequency interferometry Case 1: Homogeneous ground model Case 2: Two-layer ground model RFI instrumentation Low frequency methods Point Barrow sites Results and discussion Site 1: Tundra Site 2: Beach ridge Site 3: Marsh Conclusions Literature cited Appendix A: Discussion of low-frequency geophysical methods
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  • 54
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-86/2
    In: CRREL Report, 86-2
    Description / Table of Contents: The behavior of reinforced and unreinforced concrete beams was studied under impact loading at low temperatures, and the results were compared to the behavior of reinforcing steel (rebar) in Charpy-V impact tests. Transition temperatures as low as -30°C were obtained for the rebars in the Charpy-V tests whereas no brittle failures occured in the rebars in the reinforced concrete beams at the temperature as low as -63°C, even in beams whe're the rebars were Intentionally notched. The impact strength of unreinforced concrete increases considerably at lower temperatures, thus reducing cracking of reinforcedconcrete structures and significantly increasing the safety of lightly reinforced structures.
    Type of Medium: Series available for loan
    Pages: iii, 25 Seiten , Illustrationen
    Series Statement: CRREL Report 86-2
    Language: English
    Note: Abstract Preface Introduction Tests Test specimens Test methods Results Impact strength of beanms Ductility of beams Effect of notched bars Elastic deflection of beams Impact tests on rebars Conclusions and summary Literature cited Appendix A: Beam crack patterns Appendix B: Photomicrographs of failure surfaces of some steels
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  • 55
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-86/5
    In: CRREL Report, 86-5
    Description / Table of Contents: This work presents the results of a study to examine the effects of grain size of internal microfractures in polycrystalline ice. Laboratory-prepared specimens were tested under uniaxial, constant-load creep conditions at -5 C. Grain size ranged from 1.5 to 6.0 mm. This range of grain size, under an initial creep stress of 2.0 MPa, led to a significant change in the character of deformation. The finest-grained material displayed no internal cracking and typically experienced strains of 10 to the minus 2nd power at the minimum creep rate epsilon. The coarse-grained material experienced severe cracking and a drop in the strain at epsilon min to approximately 4x10 to the minus 3rd power. Extensive post-test optical analysis allowed estimation of the size distribution and number of microcracks in the tested material. These data led to the development of a relationship between the average crack size and the average grain size. Additionally, the crack size distribution, when normalized to the grain diameter, was very similar for all specimens tested. The results indicate that the average crack size is approximately one-half the average grain diameter over the stated grain size range. A dislocation pileup model is found to adequately predict the onset of internal cracking. The work employed acoustic emission techniques to monitor the fracturing rate occurred. Other topics covered in this report include creep behavior, crack healing, the effect of stress level on fracture size and the orientation of cracked grains. Theoretical aspects of the grain size effect on material behavior are also given.
    Type of Medium: Series available for loan
    Pages: v, 79 Seiten , Illustrationen
    Series Statement: CRREL Report 86-5
    Language: English
    Note: CONTENTS Abstract Preface Background Present research in perspective Explanations of the grain-size dependency Grain size effects on the ductile to brittle transition Nucleation mechanisms and modeling Characteristic size of nucleated crack Cracking in ice Detection of internal fracturing by acoustic emission techniques Test methods Specimen preparation Creep testing apparatus Crack length and crack density measurements Crack healing measurements Thin section photographs Grain size determination Acquisition of acoustic emission data Presentation of results Specimen characteristics Microcrack measurements Creep behavior Crack healing Slip plane length distribution Acoustic emission observations Grain orientation Analysis and discussion Thick section observations The grain size vs crack size relationship Crack nucleation condition Crack density and specimen strain Creep behavior Normalized crack length Location of cracks Acoustic emission activity Summary and conclusions Suggestions for future work Literature cited Appendix A: Crack length histograms Appendix B: Crystal orientations
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  • 56
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    Call number: ZSP-201-86/10
    In: CRREL Report, 86-10
    Description / Table of Contents: Icing of a four-bladed rotor was studied under natural conditions at the top of Mt. Washington, N.H. The rotor had two cylindrical blades and two airfoil blades. The results were compared with studies conducted in icing wind tunnels. Considerable differences in icing regimes were observed. For instance, with comparable liquid water content and wind speed the wet-to-dry growth regime transition temperature was up to 10 C higher under natural conditions than in the wind tunnel studies. Results of other studies made under natural conditions were close to those of the present study, indicating that wind tunnel conditions are significantly different from natural conditions. Close examination of the conditions indicated that supersaturation of water vapor existing in most of the wind tunnel studies is the most probable cause of the differences.
    Type of Medium: Series available for loan
    Pages: v, 68 Seiten , Illustrationen
    Series Statement: CRREL Report 86-10
    Language: English
    Note: CONTENTS Abstract Preface Introduction Site weather Site selection Equipment Rotor Data logger Rotoscope Laser profile camera Thin section preparation Run procedure Sample collection and shutdown Dry runs and static runs Results and discussion Wet-to-dry growth regime transition Stagnation line icing rate Icing rate on cylindrical and airfoil blades Liquid water content vs stagnation line icing rate Droplet capture efficiency index Temperature rise Morphological and crystallographic aspects Summary and conclusion Literature cited Appendix A: Chronology of events .. Appendix B: Narrative description of icing runs Appendix C: Weather summary sheets for test days Appendix D: Signal conditioner circuit diagram and sample printout
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  • 57
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    Call number: ZSP-201-87/20
    In: CRREL Report, 87-20
    Description / Table of Contents: The structure and salinity characteristics of saline ice slabs removed from ice sheets grown in an outdoor pool have been studied and related to the complex relative dielectric permittivity measured with free-space transmission techniques at 4.80 and 9.50 GHz. The saline ice closely simulated arctic sea ice in its structural and salinity characteristics, which were regularly monitored in a number of ice sheets grown during the winters of 1983-84 and 1984-85. In-situ transmission measurements at similar frequencies were also made on the ice sheets themselves using antennas located above and beneath the ice. The slab measurements were made during warming from -29° to -2°C on slabs grown during the winter of 1983-84 (4.75 GHz) and during a warming and cooling cycle over a slightly larger temperature range on slabs grown during the winter of 1984-85 (4.80 and 9.50 GHz).
    Type of Medium: Series available for loan
    Pages: v, 41 Seiten , Illustrationen
    Series Statement: CRREL Report 87-20
    Language: English
    Note: CONTENTS Abstract Preface Part I - Structural properties Introduction Experimental setup Analytical techniques Results and discussion 1983-84 experiments 1984-85 experiments Conclusions and recommendations Part Il - Microwave properties Introduction Measurement techniques Results 1983-84 experiments 1984-85 experiments 1984-85 in-situ experiments Discussion Comparison of data Analytical modeling Summary and conclusions Literature cited Appendix A: Dielectric mixing model of sea ice
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  • 58
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    Call number: ZSP-201-83/18
    In: CRREL Report, 83-18
    Description / Table of Contents: An evaluation of an impulse radar system for detecting cavities under concrete pavement is discussed, and field results are presented. It was found that a dual antenna mode of surveying was ideal for void detection. In this mode one antenna operated in a transceive mode and a second, offset from the first, operated in a receive-only mode. This arrangement allowed a refraction-type profile survey to be performed, which enabled subpavement voids to be easily detected. Field trails were held at Plattsburgh Air Force Base, where 28 cavities were detected and mapped. Drilling of holes verified that a cavity existed and allowed cavity depth to be measured. The cavities varied from 1.5 in. to 23 in, depth and were up to 20 ft. long.
    Type of Medium: Series available for loan
    Pages: 49 Seiten , Illustrationen
    Series Statement: CRREL Report 83-18
    Language: English
    Note: CONTENTS Abstract Preface Introduction Plattsburgh Air Force Base Radar sounding system Survey procedure Cavity inspection Radar cavity detection test Radar profile results Falling-weight deflectometer tests Discussion and conclusions Literature cited
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  • 59
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    Call number: ZSP-201-83/13
    In: CRREL Report, 83-13
    Description / Table of Contents: A review on past experimental and theoretical work indicates a need for additional experimentation to characterize the response of snow to inelastic pressure waves. Pressure data from previously conducted explosion tests are analyzed to estimate the elastic limit of snow of 400 -kg/cu m density to be about 36 kPa. This pressure corresponds to a scaled distance of 1.6 m/cu.rt.kg for charges fired beneath the surface of the snow, and to a scaled distance of 1.2 m/cu.rt.kg for charges fired in the air. The effects of a snow cover on the method of clearing a minefield by using an explosive charge fired in the air above the snow surface are also discussed and recommendations are given for further work in this area. Explosive pressure data are used to estimate the maximum effective scaled radius for detonating buried mines at shallow depth to be 0.8 m/cu.rt.kg. Fuel-air explosive will increase this effective radius significantly because of the increase in the size of the source region.
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    Pages: 33 Seiten , Illustrationen
    Series Statement: CRREL Report 83-13
    Language: English
    Note: CONTENTS Abstract Preface List of symbols Introduction Objectives Background Problems in describing the response of snow to an applied stress Methods of determining the dynamic behavior of materials Review of previous studies on snow Experimental measurements on snow Summary of snow experiments Theoretical studies Confirmation of the theory Discussion Applications Recommendations Summary Literature cited Appendix A. Selected data from Wisotski and Snyder (1966) Appendix B. Pressure data from Livingston (1964)
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  • 60
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    Call number: ZSP-201-84/18
    In: CRREL Report, 84-18
    Description / Table of Contents: This report investigates the influences of turbulence and water temperature on frazil ice formation. The rate and thequantity of frazil ice formed in a specified volume of supercooled water increase with both increasing turbulence inten-sitv and decreasing water temperature. The influence of turbulence intensity on the rate of frazil ice formation, how-ever. is more pronounced for larger initial supercooling. The turbulence characteristics of a flow affect the rate offrazil ice formation by governing the temperature to which the flow can be supercooled, by influencing heat transferfrom the frazil ice to surrounding water, and by promoting collision nucleation, particle and floc rupture and increasingthe number of nucleation sites. larger frazil ice particles formed in water supercooled to lower temperatures. The par-ticles usually were disks, with diameters several orders greater than their thickness. Particle size generally decreased with increasing turbulence intensity. This report develops an analytical model, in which the rate of frazil ice formation isrelated to temperature rise of a turbulent volume of water from the release of latent heat of fusion of liquid water toice. Experiments conducted in a turbulence jar with a heated, vertically oscillating grid served both to guide and tocalibrate thanalytical'model as well as to afford insights into frazil ice formation. The formation of frazil ice wasstudied for Vemperatures of supercooled water ranging from -0.9° to -0.050°C.
    Type of Medium: Series available for loan
    Pages: vi, 50 Seiten , Illustrationen
    Series Statement: CRREL Report 84-18
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Background Scope of study Literature review Introduction Incipient formation of frazil ice Particle size and evolution of frazil ice Influences of turbulence and water temperature on the rate of frazil ice formation Conclusions Analytical model Introduction Elements of heat transfer Elements of turbulence Experimentation Experimental apparatus Experimental procedure Results Introduction Nucleation of frazil ice Influences of turbulence on frazil ice formation Water temperature Influences of water temperature and turbulence on the concentration of frazil ice Frazil ice particle shape and size Conclusions Literature cited Appendix A: Preliminary frazil ice experiments Flume experiments Couette-flow Appendix B: Listing of computer program for calculation of frazil ice formation Appendix C: Water temperature rise attributable to frazil ice formation as computed usingthe analytical model .
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  • 61
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    Call number: ZSP-201-82/23
    In: CRREL Report, 82-23
    Description / Table of Contents: A direct filtration, water treatment pilot plant was operated on the Kenai River at Soldotna, Alaska, during the summer of 1980. The purpose of the pilot plant operations was to determine the feasibility of the direct filtration process for removal of glacial silt. The major criterion used to determine feasibility was production of water containing less than 1.0 NTU of turbidity. For the range of raw water turbidities encountered (22-34 NTU), the pilot plant testing indicated that direct filtration was feasible and could be considered as an alternative to conventional waiter treatment plants containing sedimentation tanks.
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    Pages: 26 Seiten , Illustrationen
    Series Statement: CRREL Report 82-23
    Language: English
    Note: CONTENTS Abstract Preface Conversion factors: U.S. customary to metric Introduction Glacial characteristics Water treatment Materials and methods Experimental design Pilot plant intake Hydrocyclone Chemical addition system Flocculation system Filtration system Pilot plant operations Coagulant chemical preparations Flow measurement Sampling Results and discussion Kenai River w ater quality Evaluation of pilot plant testing Performance of pilot plant elements Physical and chem ical variables Conclusions Recommendations Literature cited
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  • 62
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    Call number: ZSP-201-85/18
    In: CRREL Report, 85-18
    Description / Table of Contents: Concern over the environmental fate of explosives has brought about the development of sensitive analytical methods for measuring them in groundwater. In turn this concern has been extended to validating the sampling procedures for groundwater. This report addresses the potential effects of residual drilling muds on the analysis for explosive contaminants (TNT, DNT, RDX, and HMX) in monitoring wells. The approach was to determine sorption isotherms for each contaminant. Sorption appeared to be independent of solids concentration. Linear isotherms were obtained for RDX and HMX over a range of analytic concentrations; therefore, a single constant can be used to estimate the amount sorbed when the solution concentration is known. Isotherms for TNT and DNT were not linear, however. Scatchard analysis suggested that the isotherms for these analytes could be resolved into two predominant components: a linear component above a certain sorbed quantity and a Langmuir-type component below this quantity. The experimental data were fitted by regression analysis using the appropriate model. The equations developed can be used to predict the sorbed fraction (analytical bias) for any combination of solids and analyte concentration. The amounts of bentonite found in some existing wells do not appear to be sufficient to cause significant bias in analyses for these explosive contaminants.
    Type of Medium: Series available for loan
    Pages: iv, 40 Seiten , Illustrationen
    Series Statement: CRREL Report 85-18
    Language: English
    Note: CONTENTS Abstract Preface Introduction Materials and methods Bentonite and water samples Sorbate solutions Sorption isotherms HPLC analysis Analyte standards Water solubilities Octanol-water partition coefficients Sorption isotherms Freundlich Langmuir BET Scatchard Gibbs Linear Polynomial Results and discussion TNT DNT RDX and HMX Effect of drilling muds on analysis SEM and EDXA analysis of bentonite wells Other studies Summary Literature cited Appendix A : Results for TNT Appendix B: Results for DNT Appendix C: Results for RDX Appendix D : Results for HMX Appendix E: Characteristics of Quik-Gel, Aqua-Gel and well water
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  • 63
    Call number: ZSP-980-70
    In: 2nd Working Meeting "Radioisotope Application and Radiation Processing in Industry", Part 2, 50 to 97
    In: ZfI-Mitteilungen, Nr. 70
    Type of Medium: Series available for loan
    Pages: 355 Seiten , Illustrationen
    ISSN: 0323-8776
    Series Statement: ZfI-Mitteilungen 70
    Language: English
    Note: Contents of Part 2 Hecht, K. Gerber, R. Otto: Studies on the drying of paints by means of 14C-labelled compounds K. Wagner, F. Brutschin, I. Ritter, T. Gritsch, H. Zimmermann, H. Borchert: Investigations by the aid of radioisotope methods on the technology of the production of carbon and silicon carbide materials K. Gloe, P. Mühl: Determination of metal extraction process parameters using tracer technique W. Migdał, W. Łada, K. Malec-Czechowska: Studies on liquid-liquid extraction of noble metals using radiotracers L. Petryka, K. Przewłocki: Radiotracer investigations of benefication copper ore in the industrial flotation process Z. Bazaniak, J. Palige: Determination of Cu recovery degree from slags in shaft process by means of radiotracers R. Burek, J .K. Zurawicz: On the optimization of concentration measurements in heterogeneous materials based on β-backscatter measurements B. Heinrich: Analysis of carbon content in crude brown coal by inelastic scattering of neutrons and the method of time correlated associated particles P. Urbańaki, D. Wagner, M. Jankowska, E. Kowalska: Determination of calcium and iron and measurements of ash content in the brown coal H.-W. Thümmel: Some considerations relating to the prediction of the efficiency of radiometric methods for the continuous ash content determination of coal L. Wawrzonek: Monitor of ash content of coal with X-ray source I. Pavlicsek, V. Stenger, A. Veres: Apparatus for gamma activation analysis I. Végvári, I. Juhász: Determination of PbO content of lead-glass samples on the ground of gamma-absorption E. Schöntube, H.-J. Große: Aerosol ionization gas analysis as a monitoring for waste halothane in the atmosphere of operating theatre S. Mothes, P. Popp, G. Oppermann, W.-D. Herberg: Measurement of fluorocarbons with the ECD P. Popp, E. Schöntube, G. Oppermann: The usability of radiation ionization detectors for the determination of N2O concentrations in the air of operating theatres P. Popp, G. Arnold, G. Oppermann: A hydrocarbon-sensitized argon ionization detector for the detection of inorganic compounds R. Szepke, W. Lisieski, J. Harasimczuk: Automatic dust monitor AMIZ G. Vormum: Sealed sources - problems of design, measurement and quality control L. Gąsiorowski: New trends in developments of ratioisotope gauges in Poland G. Brunner: Direct chemical information from special radio tracers as well as from outer X-ray excitation J. Hirling: Experience and future trend in industrial application of nuclear methods in Hungary I. N. Ivanov, O. K. Nikolaenko, Yu. V. Phecktistov, V. L. Chulkin: Use of short-lived nuclides in activation analysis Kl.-P. Rudolph, J. Flachowsky, A. Lange: Trace element determination in semiconducter selenium by neutron activation analysis (NAA) W. Lisieski, J. Mirowicz: Some industrial applications of instruments with neutron sources R. Dybczyński, H. Maleszewaka, S. Sterliński, Z. Szopa, M. Wasek: Some problems in neutron activation determination of gold and silver in ores and concentrates of copper industry L. Jankowski: Cost-benefit aspects of radioisotope application in industry B. Manouchev, T. Boschkova, L. Tsankov, V. Gurev, I. Kojucharov, G. Grozev: On the possibilities of the direct gamma-spectremetry in natural waters P. Morgenstern, D. Müller, W. Riedel: A parallel grid proportional scintillation counter for the X-ray region from 3 to 20 keV with regard to high count rates N. A. Anders, V. S. Isaev, V. I. Filatov, B. E. Kolesnikov, D. Müller, P. Morgenstern, W. Riedel, V. P. Varvaritsa: X-ray fluroescence analyzer of light elements with proportional scintillation counter D. Müller, P. Morgenstern, W. Riedel, W. Warwariza, B. E. Kolesnikow, N. A. Anders, W. J. Filatov: General considerations concerning the use of the X-ray analyzer "RALE" in industry
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  • 64
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    Call number: ZSP-201-83/9
    In: CRREL Report, 83-9
    Description / Table of Contents: Recent observations of shore ice pile-up and ride-up along the coast of the Alaska Beaufort Sea are presented. Information is given to show that sea ice movement on shore has overridden steep coastal bluffs and has thrust inland over 150 m, gouging into and pushing up mounds of beach sand, gravel, boulders and peat and, inland, the tundra material. The resulting ice scar morphology was found to remain for tens of years. Onshore ice movements up to 20 m are relatively common, but those over 100 m are very infrequent. Spring is a dangerous time, when sea ice melts away from the shore, allowing ice to move freely. Under this condition, driving stresses of less than 100 kPa can push thick sea ice onto the land.
    Type of Medium: Series available for loan
    Pages: v, 59 Seiten , Illustrationen
    Series Statement: CRREL Report 83-9
    Language: English
    Note: Contents Abstract Preface Introduction Winter 1979-80 observations Winter 1980-81 and summer 1981 observations Winter 1981-82 and summer 1982 observations Old ice ride-up features Discussion Literature cited Appendix A. The boulder rampart and rock littered shore west of Konganevik Pt. Appendix B. Site location maps
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  • 65
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    Call number: ZSP-201-83/6
    In: CRREL Report, 83-6
    Description / Table of Contents: During the austral summers of 1976-77 and 1978-79, several ice cores were taken from the McMurdo Ice Shelf brine zone to investigate its thermal, physical and chemical properties. This brine zone consists of a series of super-imposed brine layers (waves) that originate at the seaward edge of the ice shelf and migrate at various rates, depending upon their age and position in the ice shelf. The brine in these layers becomes increasingly concentrated as the waves migrate inland through the permeable ice shelf firn. Chemical analyses of brine samples from the youngest (uppermost) brine wave show that it contains sea salts in normal seawater proportions. Further inland, deeper and older brine layers, though highly saline (S 〉 200 ‰), are severely depleted in SO2-4 with the SO2-4/Na+ ratio being an order of magnitude less than that of normal seawater. Analyses of Na+, K+, Ca2+, Mg2+, SO2-4 and CI-, together with solubility and temperature considerations, show that the sulfate depletion is due to selective precipitation of mirabilite, Na2SO4*10H2O. The location of the inland boundary of brine penetration is closely related to the depth at which the brine en-counters the firn/ice transition. However, a small but measurable migration of brine is still occurring in otherwise impermeable ice; this is attributed to eutectic dissolution of the ice by concentrated brine as it moves into deeper and warmer parts of the McMurdo Ice Shelf.
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    Pages: iii, 16 Seiten , Illustrationen
    Series Statement: CRREL Report 83-6
    Language: English
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  • 66
    Call number: ZSP-201-83/7
    In: CRREL Report, 83-7
    Description / Table of Contents: Peak power generation with hydropower creates tailwater flow conditions characterized by high and low flows with abrupt transitions between these states. Flows occurring in tailwaters typically form sharp-fronted, large-amplitude waves of relatively short period. An understanding of the mechanics of downstream propagation of these waves is important both for direct application in studies of the tailwater and because of the similarity of these waves to those following a dam break. An analysis of the dynamic equations of open channel flow is used to quantify the relative importance of flow wave convection, diffusion and dispersion in rivers. The relative importance of each process is re­lated to the relative magnitude of terms in the dynamic equations, providing a physical basis for model formulation. A one-dimensional diffusion wave flow routing model, modified for tailwaters, simulates the important physical pro­cesses affecting the flow and is straightforward to apply. The model is based upon a numerical solution of the kine­matic wave equation. The “modified equation,” Hirt, and von Neumann analyses are used to gain insight into the stability and dissipative and dispersive behavior of the numerical solution, and results of these analyses are compared. A set of linear routings is used to demonstrate the dissipative and dispersive behavior predicted by the analyses and to verify the accuracy of an expression that quantifies the numerical diffusion of the model. The analyses provide a basis for selection of numerical parameters for model applications. The capability and accuracy of the model are enhanced when physical wave diffusion is balanced by numerical diffusion in the model. Maintaining the diffusion balance re­quires that the time derivative weighting parameter 0 be variable and in some instances negative. Though some amount of phase error is introduced, negative 0 values have no adverse effect upon model stability. Field studies were con­ducted to demonstrate the benefits of careful model development and analysis, and to verify the diffusion wave model for rapidly varying tailwater flow. The bed slope and roughness characteristics of the field study reaches (below Apalachia and Norris Dams) differ greatly, spanning those of a large number of rivers of practical interest. The accurate simulation of flow in both of these tailwaters attests to the soundness of both the physical basis of the model and the numerical solution technique. The field studies confirm, for the extreme case of rapidly varying flow in a mildly sloped river, that inertia has a negligible effect upon unsteady flow waves at low Froude numbers. Additionally, these studies verify that diffusion of short-period waves in rivers is generally significant.
    Type of Medium: Series available for loan
    Pages: vi, 41 Seiten , Illustrationen
    Series Statement: CRREL Report 83-7
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Physical diffusion and dispersion in open channel flow Modeling approach Description of the diffusion wave flow routing model Analysis of the numerical model Modified equation and Hirt analyses of diffusion wave model von Neumann analysis of the diffusion wave model Linear case studies Accuracy considerations of the numerical solution Field studies Apalachia Dam tailwater Norris Dam tailwater Conclusions Literature cited
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  • 67
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    Call number: ZSP-201-83/5
    In: CRREL Report, 83-5
    Description / Table of Contents: This report presents the results of dynamic ice-structure interaction model tests conducted at the CRREL Ice Engineering Facility. A flexible, single-pile, bottom-founded offshore structure was simulated by a test pile with about a one-to-ten scale ratio. Urea (instead of sodium chloride) was used as dopant to scale down the ice properties, resulting in good model ice properties. Six ice fields were frozen and 18 tests carried out. In all cases distinctive dynamic ice structure interaction vibrations appeared, from which abundant data were collected. In tests with linear ice velocity sweep, sawtooth-shaped ice force fluctuations occurred first. With increasing velocity the natural modes of the test pile were excited, and shifts from one mode to another occurred. The maximum ice force values appeared mostly with low loading rates, but high forces appeared random'y at high ice velocities. As a general trend, ice force maximums, averages and standard deviations decreased with increasing ice velocities. The aspect ratio effect of the ice force in continuous crushing follows the same dependence as in static loadings. The frequency of observed ice forces is strongly dominated by the natural modes of the structure. Dynamically unstable natural modes tend to make the developing ice force frequencies the same as the natural frequencies. Otherwise the resulting frequency depends directly on structural stiffness and ice velocity and inversely on the ice force range. During vibrations the displacement rates of the structure overcome the velocity of ice, making low loading rates and hence high ice forces possible. During crushing, ice induces both positive and negative damping.
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    Pages: iv, 53 Seiten , Illustrationen
    Series Statement: CRREL Report 83-5
    Language: English
    Note: CONTENTS Abstract Preface Introduction Test arrangements Ice properties Crushing patterns Maximum ice force vs velocity Dynamic aspect ratio effect and crushing strength Measured ice force frequencies Calculated ice force frequencies Accelerations, velocities and displacements Damping Ice-induced negative damping Limit cycles Buckling load Conclusions Literature cited
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  • 68
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    Call number: ZSP-201-82/13
    In: CRREL Report, 82-13
    Description / Table of Contents: Frost heave is analyzed for the common case in which some ice penetrates the soil. In this situation, heave is due to the accumulation of soil-free ice just within the frozen zone, behind a frozen fringe of finite thickness. Heat and mass transport within and across that fringe are crucial processes in the dynamics of heave. This analysis concentrates on activity within the fringe, also connecting that activity to heat and mass flows in the more frozen and unfrozen zones. Each component in a set of governing differential equations is developed from rational physics and thermodynamics, using previous experimental work. It is assumed that the soil ice grows through interconnected interstices; hence it constitutes and can move as a rigid body. When the assumption is translated into mathematical terms, it completes the governing equations. The model resulting from these considerations is a one-dimensional finite element computer program that solves the equations for arbitrary initial and boundary conditions. The model is used to simulate the heave history of a hypothetical soil column frozen unidirectionally and subjected to a surcharge. The results are gratifying in that they predict qualitatively the characteristics of numerous laboratory observations. Some questions about the completeness of the theory remain, and strict verification of the model awaits further experimentation and better parameter identification.
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    Pages: iii, 11 Seiten , Illustrationen
    Series Statement: CRREL Report 82-13
    Language: English
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  • 69
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    Call number: ZSP-201-82/11
    In: CRREL Report, 82-11
    Description / Table of Contents: The purpose of this investigation was to provide data to be used in evaluating the effects of winter navigation on pro­cesses that cause bank erosion. The specific objectives were to document bank conditions and erosion sites along the rivers, to monitor and compare the amounts of winter and summer bank recession and change, and to estimate the amount of recession that occurred prior to winter navigation. Shoreline conditions and bank recession were documented during field surveys each spring and fall. Bank changes were evaluated by comparison to observations from a previous survey. Aerial photointerpretation was done to estimate the amount of bank recession that occurred prior to winter navigation. Three hundred forty-five miles of river shoreline were surveyed. Banks were eroding along 21.5 miles (6.2%). The common types of bank failures were soil falls (sloughing) and block sliding and slumping. The erosion along approxi­mately 15 miles (70%) of the 21.5 miles was occurring along reaches not bordering winter navigation channels.
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    Pages: v, 75 Seiten , Illustrationen
    Series Statement: CRREL Report 82-11
    Language: English
    Note: CONTENTS Abstract Preface Introduction Previous investigations Approach Shoreline conditions Bank changes Bank recession before winter navigation St. Marys River Bank changes Bank recession before winter navigation St. Clair River Bank changes Bank recession before winter navigation Detroit River Bank changes Bank recession before winter navigation St. Lawrence River Bank changes Historical bank recession Summary and conclusions Literature cited Appendix A: St. Marys River Appendix B: St. Clair River Appendix C: Detroit River Appendix D: St. Lawrence River
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  • 70
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    Call number: ZSP-201-82/40
    In: CRREL Report, 82-40
    Description / Table of Contents: The use of explosives to break floating ice sheets is described, and test data are used to develop design curves that predict explosives effects as ice thickness, charge size, and charge depth vary. Application of the curves to practical problems is illustrated by numerical examples. The general features of underwater explosions are reviewed and related to ice blasting. Quasi-static plate theory is considered, and is judged to be inapplicable to explosive cratering of ice plates. The specific energy for optimized ice blasting is found to compare quite favorably with the specific energy of icebreaking ships. All available field data for ice blasting are tabulated in appendices, together with details of the re­gression analyses from which the design curves are generated.
    Type of Medium: Series available for loan
    Pages: iv, 68 Seiten , Illustrationen
    Series Statement: CRREL Report 82-40
    Language: English
    Note: CONTENTS Abstract Preface Introduction General behavior of underwater explosions Regression analysis for ice-blasting data General features of the regression curves Use of the regression curves as design curves for ice blasting Row charges and pattern charges Response of floating ice sheets to underwater explosions Specific energy and “powder factor” Summary and conclusions Literature cited Appendix A: Basic data on ice blasting Appendix B: Scaled input data Appendix C: Initial regression analysis using complete polynomial Appendix D: Regression analysis with two coefficients of the original poly­nomial deleted
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  • 71
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-83/16
    In: CRREL Report, 83-16
    Description / Table of Contents: The presence of snow on the ground can impose limitations on the mobility of wheeled and tracked vehicles. Snow depth and density are the two most easily measured snow properties that can be related to mobility over snow. Existing models of snowpack accumulation and ablation processes and models of internal snowpack structure were examined to determine if a model of the snowpack can be developed for use in predicting the snow parameters that affect mobility. Simple models, such as temperature index models, do not provide sufficient snowpack details, and the more detailed models require too many measured inputs. Components of the various models were selected from a basis of a snowpack model for predicting snow properties related to mobility over snow. Methods of obtaining the input data from some components are suggested, and areas where more development is needed are described.
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    Pages: 34 Seiten , Illustrationen
    Series Statement: CRREL Report 83-16
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Conversion of metric units Introduction Review of existing models Accumulation models Ablation models Using existing models for studying mobility Proposed snowpack model for mobility studies Model components Implementation of the model Developing input data Conclusions Literature cited
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  • 72
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-83/23
    In: CRREL Report, 83-23
    Description / Table of Contents: The problems associated with measuring stresses in ice are reviewed. Theory and laboratory test results are then presented for a stiff cylindrical sensor made of steel that is designed to measure ice stresses in a biaxial stress field. Loading tests on freshwater and saline ice blocks containing the biaxial ice stress sensor indicate that the sensor has a resolution of 20 kPa and an accuracy of better than 15% under a variety of uniaxial and biaxial loading conditions. Principal stress directions can also be determined within 5 degrees. The biaxial ice stress sensor is not significantly affected by variations in the ice elastic modulus, ice creep or differential thermal expansion between the ice and gauge. The sensor also has a low temperature sensitivity (5 kPa/deg C).
    Type of Medium: Series available for loan
    Pages: 38 Seiten , Illustrationen
    Series Statement: CRREL Report 83-23
    Language: English
    Note: CONTENTS Abstract Preface Introduction Previous work Stress measurements Design considerations Stress sensors Biaxial ice stress sensor Biaxial stress sensor theory Gauge deformation Stresses associated with cylindrical sensors Determination of ice stresses Gauge calibration Evaluation of the biaxial ice stress sensor Temperature sensitivity Biaxial loading test equipment Biaxial loading test results Differential thermal expansion Long-term drift Discussion of test results Conclusions Literature cited
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  • 73
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    Call number: ZSP-201-83/26
    In: CRREL Report, 83-26
    Description / Table of Contents: Ice accreted on high-speed rotors operating in supercooled fog can be thrown off by centrifugal force, creating severe unbalance and dangerous projectiles. A simple force balance analysis indicates that the strength of accreted ice and its adhesive strength can be obtained by measuring the thickness of the accretion, the location of the separation, the rotor speed, and the density. Such an analysis was applied to field and laboratory observations of self-shedding events. The results agree reasonably well with other observations.
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    Pages: 13 Seiten , Illustrationen
    Series Statement: CRREL Report 83-26
    Language: English
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  • 74
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-84/6
    In: CRREL Report, 84-6
    Description / Table of Contents: An expression relating aerosol growth to cold environmental conditions was developed. This was accomplished by solving the diffusion equation with the method of Laplace transformation. The series solution was expressed in terms of the dimensionless parameters K (ratio of vapor density over droplet surface to droplet density), ω (ratio of environmental vapor density at time zero to vapor density over droplet surface), and dimensionless time τ (ratio of product of diffusion coefficient D and time t to square of initial radius of condensation nucleus). To take into account the variation of the vapor density over the surface of an acidic condensation nucleus due to the continuous dilution of the droplet, the solution was obtained by assuming various levels of constant vapor concentration. The final expression [R/R sub o - 1 = 2.4917 x 10 to the minus 18th power) exp(0.0737 θ) (P sub RHS/25) x (100-P sub RHS) τ to the 0.9890 powder] can be used to compute the value of R once the values of initial radius R sub o, relative humidity P sub RH, percent of relative humidity at the droplet surface P sub RHS, and environmental temperature θ are given.
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    Pages: vi, 28 Seiten , Illustrationen
    Series Statement: CRREL Report 84-6
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature General background The problem Method of solution Results and discussion Conclusions Literature cited Appendix: Evaluation of rn's in equation 25
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  • 75
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-84/5
    In: CRREL Report, 84-5
    Description / Table of Contents: Diatom species composition and relative abundances were determined for ice cores obtained from Weddell Sea pack ice during the October-November 1981 Weddell Polynya Expedition (WEPOLEX). Ice thickness and salinity indicate that the ice was less than one year old. The predominant ice type (70%) was frazil, which has the capacity to mechanically incorporate biological material through nucleation and scavenging. Diatoms were found throughout the length of the cores. Species showed down-core fluctuations in abundance that appeared to be correlated with changes in ice type. Pennate forms were more abundant than centrics, the average ratio being 16:1. Diatom frustules with intact organic material were more abundant (5 billion cells/liter). Differences in species abundances are attributed initially to incorporation of algal cells from a temporally changing water column and subsequently to diatom reproduction within the ice. Scanning electron micrographs illustrating the morphologic characteristics of the predominant species are included.
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    Pages: iv, 46 Seiten , Illustrationen
    Series Statement: CRREL Report 84-5
    Language: English
    Note: Contents Abstract Preface Introduction Materials and methods Results Discussion Conclusions Literature cited Appendix A: Taxonomic terms Appendix B: Differences in species composition and abundance in duplicate samples examined under optical and inverted light microscopes Appendix C: Morphologic descriptions and SEM micrographs
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  • 76
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-89/21
    In: CRREL Report, 89-21
    Description / Table of Contents: The physical characteristics of blue ice ablation areas in Antarctica are described and some representative ablation rates are given. The possibilities for using blue-ice areas as airfields are outlined and exploratory surveys are mentioned. Site details are given for icefields at Mount Howe, Mill Glacier, Patriot Hills, Rosser Ridge, Mount Lechner, S1 near Casey station, and on the Ross Ice Shelf near McMurdo station. The surface roughness of blue ice is discussed, microrelief surveys are presented for Mount Howe and Patriot Hills, and spectral analyses are used to develop relations between bump height and wavelength. U.S. military specifications for the roughness limits of various types of runways are summarized and graphical comparisons are made with the roughness analyses for Mount Howe and Patriot Hills. Special machines for smoothing ice runways are discussed and design specifications are developed. Some notes on ground facilities and ground transport are included. Appendices give discussions of weather patterns in the Transantarctic Mountains and methodology for making spectral analyses of surface roughness. It is concluded that glacier-ice airfields for conventional transport aircraft can be developed at low cost in Antarctica. Recommendations for further work are offered.
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    Pages: v, 105 Seiten , Illustrationen
    Series Statement: CRREL Report 89-21
    Language: English
    Note: CONTENTS Abstract Preface Introduction Blue-ice areas Blue-ice areas as airfield sites The formation of blue-ice areas Ablation rates at blue-ice areas Exploratory surveys at blue-ice areas Mount Howe Mill Glacier / Plunket Point Patriot Hills Rosser Ridge Mount Lechner The S-1 site near Casey station The McMurdo "Pegasus Site" Surface roughness of blue ice Analysis and characterization of surface roughness Surface preparation to reduce ice roughness Ground facilities Ground transport Conclusions and recommendations Literature cited and selected references Appendix A: Survey data for Patriot Hills, Mount Howe and Mill Glacier Appendix B: Analysis of surface roughness at blue-ice sites Appendix C: Meteorological conditions to be expected in summer in the Trans-antarctic Mountains
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  • 77
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-80/8
    In: CRREL Report, 80-8
    Description / Table of Contents: This report presents the results of the tests on the new U.S. Coast Guard 140-ft icebreaker Katmai Bay (WTGB-101) in the level plate ice and brash ice in Whitefish Bay and the St. Marys River. The results indicate that the vessel can penetrate 22 in. of level freshwater ice with 2-3 in. of snow cover. It can also penetrate up to 48 in. of brash ice in a continuous mode and at least 30 in. of plate ice by backing and ramming. The installed bubbler system decreased the required power of the vessel from 10 to 30% in brash ice and 25 to 35% in level ice. The low friction coating appears to be effective in decreasing the friction factor when it remains intact; when it peels off it appears to make conditions worse than plain paint. An average dynamic friction factor of 0.15 could be used over the entire hull for these tests.
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    Pages: iv, 28 Seiten , Illustrationen
    Series Statement: CRREL Report 80-8
    Language: English
    Note: CONTENTS Abstract Preface Metric conversion table Introduction Roughness and friction measurements Level plate ice performance Brash ice performance Ramming icebreaking performance Analysis of the data Propulsion efficiency in ice Regression analysis Conclusions and recommendations Literature cited
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  • 78
    Call number: ZSP-201-80/10
    In: CRREL Report, 80-10
    Description / Table of Contents: A mathematical model of coupled heat and moisture flow in soils has been developed. The model includes algorithms for phase change of soil moisture and frost heave and permits several types of boundary and initial conditions. The finite element method of weighted residual (Galerkin procedure) was chosen to simulate the spatial regime and the Crank-Nicholson method was used for the time domain portion of the model. To facilitate evaluation of the model, the heat and moisture fluxes were essentially decoupled; moisture flux was then simulated accurately, as were heat flux and frost heave in a laboratory test. Comparison of the simulated and experimental data illustrates the importance of unsaturated hydraulic conductivity. It is one parameter which is difficult to measure and for which only a few laboratory test results are available. Therefore, unsaturated hydraulic conductivities calculated in the computer model may be a significant source of error in calculations of frost heave. The algorithm incorporating effects of surcharge and overburden was inconclusively evaluated. Time-dependent frost penetration and frost heave in laboratory specimens were closely simulated with the model. After 10 days of simulation, the computed frost heave was about 2.3 cm vs 2.0 cm and 2.8 cm in two tests. Frost penetration was computed as 15 cm and was measured at 12.0 cm and 12.2 cm in the two laboratory samples after 10 days.
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    Pages: v, 49 Seiten , Illustrationen
    Series Statement: CRREL Report 80-10
    Language: English
    Note: CONTENTS Abstract Preface Introduction One-dimensional equations of simultaneous heat and moisture flux Moisture transport Heat transport Phase change Coupling effects Frost heave algorithm Development of computer model Finite difference vs finite element method Finite element formulation Time domain solution Evaluation of the mathematical model Heat flux Moisture flux Numerical dispersion Frost heave of homogeneous laboratory samples Conclusions Recommended studies to refine the model Literature cited Appendix A. Work plan, staffing and instrumentation requirements for correlating results oflaboratory frost susceptibility tests with field performance Appendix B. Proposed investigation of thaw weakening of subgrade soil and granular unboundbase course Appendix C. Derivation of finite element system matrices
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  • 79
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-81/10
    In: CRREL Report, 81-10
    Description / Table of Contents: Abstract: This treatise thoroughly reviews the subjects of density, thermal expansion and compressibility of ice; snow density change attributed to destructive, constructive and melt metamorphism; and the physics of regelation and the effects on penetration rate of both the thermal properties of the wire and stress level. Heat capacity, latent heat of fusion and thermal conductivity of ice and snow over a wide range of temperatures were analyzed with regression techniques. In the case of snow, the effect of density was also evaluated. The contribution of vapor diffusion to heat transfer through snow under both natural and forced convective conditions was assessed. Expressions representing specific and latent heat of sea ice in terms of sea ice salinity and temperature were given. Theoretical models were given that can predict the thermal conductivities of fresh bubbly ice and sea ice in terms of salinity, temperature and fractional air content.
    Type of Medium: Series available for loan
    Pages: 27 Seiten , Illustrationen
    Series Statement: CRREL Report 81-10
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Density, thermal expansion and compressibility of ice Density Thermal expansion Compressibility Density changes in snow Compaction Destructive metamorphism Constructive metamorphism Melt metamorphism Regelation Thermal properties of snow and fresh-water ice Heat capacity of snow and ice Latent heat Thermal conductivity of ice Thermal conductivity of snow Effective thermal diffusivity Heat transfer by water vapor diffusion in snow Heat and vapor transfer with forced convection Thermal properties of sea ice Specific heat of sea ice Heat of fusion of sea ice when 0° 〉 θ 〉 -8.2°C Density and thermal conductivity of sea ice Composition and air bubble content of sea ice above -8.2°C Thermal conductivity model for sea ice Thermal diffusivity of sea ice Method of determining thermal diffusivity Summary Literature cited
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  • 80
    Call number: ZSP-201-86/11
    In: CRREL Report, 86-11
    Description / Table of Contents: This initial study of the ice-covered Tanana River, near Fairbanks, Alaska, attempted to 1) establish field methods for systematic and repetitive quantitative analyses of an ice-covered river's regime, 2) evaluate the instruments and equipment for sampling, and 3) obtain the initial data of a long-term study of ice cover effects on the morphology, hydraulics and sediment transport of a braided river. A methodology was established, and detailed measurements and samplings, including profiling by geophysical techniques, were conducted along cross sections of the river. A small, portable rotary drill rig equipped with a 356-mm (14-in.) ice auger was used to cut large diameter holes in the ice cover for through-the-ice measurements. Portable heat sources and a heated shelter were required to continuously thaw and dry equipment for the repetitive measurements. Measurements included ice cover thickness, water level, water depth, temperature, flow velocity, suspended load and bed load, frazil ice distribution and bed material composition. Remotely gathered data included apparent resistivity and subsurface radar profiling. The various techniques, sampling gear and problems encountered during use in the subfreezing cold are described in detail in this report.
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    Pages: v, 49 Seiten , Illustrationen
    Series Statement: CRREL Report 86-11
    Language: English
    Note: CONTENTS Abstract Preface Introduction Study objectives and field locale Study site Equipment Vehicles Drilling equipment Sampling equipment Geophysical equipment Shelter and icing control Surveying equipment Miscellaneous equipment Field techniques and methodology Logistics Drilling procedures Data collection Geophysical analyses Experiences summary Morphology, transport and hydraulic data Mid-winter physical characteristics Hydraulic characteristics Sediment transport Late winter physical characteristics Seasonal morphology Geophysical data interpretation Spatial morphology Frazil ice characteristics Discussion and conclusions Recommendations Equipment Research Literature cited
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  • 81
    Call number: ZSP-201-86/18
    In: CRREL Report, 86-18
    Description / Table of Contents: Findings from a six-year yield and laboratory program of frost action research in four principal areas are summarized. Research on the first topic, frost susceptibility index tests, led to selection of the Corps of Engineers frost design soil classification system as a useful method at the simplest level of testing. At a much more complex level, a new freezing test combined with a CBR test after thawing is recommended as an index of susceptibility to both frost heave and thaw weakening. Under the second topic, a soil column and dual gamma system were developed and applied to obtain soil data used in improving and validating a mathematical model of frost heave, the objective of the third research topic. The model was effectively improved, a probabilistic component was added, and it was successfully tested against field and laboratory measurements of frost heave. A thaw consolidation algorithm was added, which was shown to be useful in predicting the seasonal variation in resilient modulus of granular soils, the objective of the fourth topic. A laboratory testing procedure was developed for assessing the resilient modulus of thawed soil at various stages of the recovery process, as a function of the applied stress and the soil moisture tension, which increases as the soil gradually desaturates during recovery. The procedure was validated by means of appropriate analyses of deflections measured on pavements by a falling-weight deflectometer. Frameworks for implementing findings from the principal research topics are outlined. Keywords: Airfields, Freezing thawing, Frost heave, Frozen soil, Resilient modulus, Roads.
    Type of Medium: Series available for loan
    Pages: v, 52 Seiten , Illustrationen
    Series Statement: CRREL Report 86-18
    Language: English
    Note: Contents Abstract Preface Introduction Field test sites Frost-susceptibility index testing Index tests selected Laboratory test results Conclusions Soil column and dual gamma system Design features Test results Mathematical model of frost heave and thaw settlement Model development Numerical approach Probabilistic concepts Model verification Discussion Seasonal variation in the resilient modulus of granular soils Characterization by laboratory testing Field verification Summary of predictive approach Simulating frost heave and pavement deflection Method of evaluation Results and discussion Summary of findings Frost-susceptibility index tests Soil column and dual gamma system Mathematical model of frost heave and thaw settlement Seasonal variation in resilient modulus of granular soils Implementation of research findings Corps of engineers frost design soil classification system New laboratory freeze-thaw test Frost-heave model Repeated-load triaxial test on frozen and thawed soil Evaluation of seasonal variation of resilient modulus Literature cited
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  • 82
    Call number: ZSP-201-87/6
    In: CRREL Report, 87-6
    Description / Table of Contents: Two-phase dielectric mixing model results are presented showing the electromagnetic properties of sea ice versus depth. The modeled data are compared with field measurements and show comparable results. It is also shown how the model data can be used in support of impulse radar and airborne electromagnetic(AEM) remote sensing of sea ice. Examples of the remote measurement of sea ice thickness using impulse radar operating in the 80- to 300-MHz frequency band and low-frequency (500 to 30,000 Hz) sounding techniques are presented and discussed. Keywords: Polar regions; Radar pulses.
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    Pages: vii, 55 Seiten , Illustrationen
    Series Statement: CRREL Report 87-6
    Language: English
    Note: Contents Abstract Preface Nomenclature Introduction Sea ice growth and structure Model sea ice Brine salinity Seawater and model brine conductivity Complex dielectric constant of brine Electromagnetic properties of model sea ice at 100 MHz Electromagnetic properties of model sea ice at 100 and 500 MHz and 1 and 5 GHz Example of impulse radar sea ice profiling results Example of frequency-domain electromagnetic sea ice thickness sounding Concluding remarks Literature cited
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  • 83
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-87/10
    In: CRREL Report, 87-10
    Description / Table of Contents: Uniaxial constant-stress and constant-strain-rate compression tests were conducted on more than 200 remolded, saturated, frozen specimens of Fairbanks silt under various conditions. A series of curves of stress vs strain rate for various temperatures of strain rates ranging from about 6x10-2 to 10-8s-1show a close strength correspondence between the constant-stress and-costant strain-rate tests. All of these "complete" stress vs strain rate curves could not be described by a single power law or exponential equation, indicating that different deformation mechanisms are dominant within different ranges of strainrate Two critical strain rates for distinguishing between the different deformation mechanisms were ob-served to be near 10- 3 and 10-6 s-1 for the medium-dense frozen Fairbanks silt. The former indicates the transition from ductile failure to moderate brittle fracture as strain rate increases, while the latter indicates the transition from dislocation creep to glide creep (by the authors' definition). Based on the change in flow law, two fundamental creeps were classified: short-term creep, which is governed by glide creep, and long-term creep, which is governed by dislocation creep. The failure criterion of frozen silt has a general form of em x tm = Ef, where m depends only on density, and tm is in minutes if m is not 1. The failure strain Ef was not sensitive to temperature and strain rate over a certain range of strain rates, but it was very sensitive to density. Assur's creep model (1980) for ice was used to fit the creep data in this study. It works well for short-term creep but does not fit as well for long-term creep. The rate process theory was applied to the creep data. A very high value of experimental activation energy was obtained for lower stresses, and a very high value of apparent activation energy was observed for higher temperatures. The peak compressive strength was very sensitive to temperature and strain rate but relatively insensitive to density. While the initial tangent modulus is not-sensitive to strain rate, it increases with decreasing temperature and density.
    Type of Medium: Series available for loan
    Pages: vi, 75 Seiten , Illustrationen
    Series Statement: CRREL Report 87-10
    Language: English
    Note: CONTENTS Abstract Preface Introduction Review of previous work Specimen preparation Material Molding Testing procedure and apparatus Test results Definition of strain and stress Definition of creep failure Definition of failure in constant-strain-rate tests Definition of initial yield strength Determination of initial tangent modulus and 50% peak strength modulus Creep behavior General nature of the creep process and the failure mode Minimum creep rate Time to creep failure Relationship between t, and tm Creep failure strain and failure criterion Creep model and prediction of creep strain Strength behavior General stress-strain behavior and failure mode Peak compressive strength Initial yield strength Failure strain Initial yield strain Initial tangent modulus 50% peak strength modulus Correspondence between constant-stress tests and constant-strain-rate tests Conclusions Literature cited Appendix A: Unfrozen water content data Appendix B: Physical properties of samples tested
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  • 84
    Call number: ZSP-201-87/14
    In: CRREL Report, 87-14
    Description / Table of Contents: During February and March 1980 the physical properties of Weddell Sea pack ice were investigated via core drilling of 66 floes located along the transect of 600 nautical miles from 64°S to 74°S latitude at roughly 40°W longitude. These studies revealed widespread frazil ice in amounts not known to exist in Arctic sea ice of comparable age and thickness. It is estimated from structure studies of 62 of the 66 floes that 54% of the total ice production of the Weddell Sea is generated as frazil. The disposition and exceptional thickness of the frazil show that mechanisms other than surface turbulence effects are involved and imply that the circulation and structure of the water in the upper levels of the Weddell Sea are significantly different from those in the Arctic basin. Salinities of both first-year and multi-year floes are notably higher than those of their Arctic counterparts because summer surface melting is rare or absent in the Weddell Sea; in the Arctic, downward percolating meltwater flushes through the ice and lowers its salinity. Fluorescence was evaluated as a means of revealing biological activity in Weddell Sea pack ice. It proved useful as an index of combined living and dead material in the ice, but measurements failed to establish any consistent relationship between fluorescence and salinity as suggested be earlier work in the Weddell Sea.
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    Pages: iv, 80 Seiten , Illustrationen
    Series Statement: CRREL Report 87-14
    Language: English
    Note: CONTENTS Preface Introduction Sea ice structure and classification Logistics and field operations Analytical techniques Crystalline structure Fluorescence Results Salinity Crystalline structure Fluorescence Description of selected floes Conclusions Literature cited Appendix A: Floe descriptions
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  • 85
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-82/38
    In: CRREL Report, 82-38
    Description / Table of Contents: Extreme cold causes heavy buildup of frost, ice and condensation on many windows. It also increases the incentive for improving the airtightness of windows against heat loss. Our study shows that tightening specifications for Alaskan windows to permit only 30% of the air leakage allowed by current American airtightness standards is economically attractive. We also recommend triple glazing in much of Alaska to avoid window icing in homes and barracks. We base our conclusions on a two-year field study of Alaskan military bases that included recording humidity and temperature data, observing moisture accumulation on windows and measuring airtightness with a fan pressurization device.
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    Pages: v, 26 Seiten , Illustrationen
    Series Statement: CRREL Report 82-38
    Language: English
    Note: Contents Abstract Preface Nomenclature Introduction Previous work in cold weather window performance Investigation Data acquisition and analysis Modeling the window thermal regime Moisture and ice observations Airtightness testing and analysis Annual heat loss from air leakage Results and conclusions Moisture on windows Airtightness Airtightness economics Recommendations for windows in extreme cold Airtightness Multiple glazing Literature cited Appendix A: Moisture levels and airtightness Appendix B: Dewpoint data Appendix C: Sample observations of icing
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  • 86
    Call number: ZSP-201-82/39
    In: CRREL Report, 82-39
    Description / Table of Contents: Observations of a 4.4-m-high brine step in the McMurdo Ice Shelf, Antarctica, show that it has migrated about 1.2 km in 4 years. The present brine wave is overriding an older brine-soaked layer. This migration is proof of the dynamic nature of the step, which is the leading edge of a brine wave that originated at the shelf edge after a major break-out of the McMurdo Ice Shelf. The inland boundary of brine penetration is characterized by a series of descending steps that are believed to represent terminal positions of separate intrusions of brine of similar origin. The inland boundary of brine percolation is probably controlled largely by the depth at which brine encounters the firn/ ice transition (43 m). However, this boundary is not fixed by permeability considerations alone, since measurable movement of brine is still occurring at the inland boundary. Freeze-fractionation of the seawater as it migrates throught the ice shelf preferentially precipitates virtually all sodium sulfate, and concomitant removal of water by freezing in the pore spaces of the infiltrated firm produces residual brines approximately six times more concentrated than the original seawater.
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    Pages: v, 35 Seiten , Illustrationen
    Series Statement: CRREL Report 82-39
    Language: English
    Note: CONTENTS Abstract Preface Introduction Objectives Analytical techniques Radio echo profiling Core drilling Results and discussion Brine infiltration survey Brine layer steps Brine infiltration characteristics Brine infiltration mechanisms at inland boundary Confirmation of brine depths by drilling Density and temperature profiles Ice shelf freeboard Brine upwelling Brine chemistry Conclusions Literature cited
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  • 87
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-82/36
    In: CRREL Report, 82-36
    Description / Table of Contents: Camp construction and drilling activities in 1950 at the East Oumalik drill site in northern Alaska caused extensive degradation of ice-rich, perennially frozen silt and irreversible modification of the upland terrain. In a study of the long-term degradational effects at this site, the near-surface geology was defined by drilling and coring 76 holes (maximum depth of 34 m) in disturbed and undisturbed areas and by laboratory analyses of these cores. Terrain disturbances, including bulldozed roads and excavations, camp structures and off-road vehicle trails, were found to have severely disrupted the site's thermal regime. This led to a thickening of the active layer, melting of the ground ice, thaw subsidence and thaw consolidation of the sediments. Slumps, sediment gravity flows and collapse of materials on slopes bounding thaw depressions expanded the degradation laterally, with thermal and hydraulic erosion removing materials as the depressions widened and deepened with time. Degradational processes became less active after thawed sediments thickened sufficiently to slow the increase in the depth of thaw and permit slope stabilization. The site's terrain is now irregular and hummocky with numerous depressions. Seasonal thaw depths are deeper in disturbed areas than in undisturbed areas and reflect the new moisture conditions and morphology. The severity of disturbance is much greater at East Oumalik than at another old drill site, Fish Creek. The difference results primarily from differences in the physical properties of the sediments, including the quantity and distribution of ground ice.
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    Pages: 42 Seiten , Illustrationen
    Series Statement: CRREL Report 82-36
    Language: English
    Note: CONTENTS Abstract Preface Summary Introduction Methodology Geologic setting Camp construction and occupation Types of disturbance Degradational processes and the effective area of impact Areal effects of disturbance Topography Groundwater, surface water and drainage Sediment properties and near-surface stratigraphy Surficial processes Depth of thaw Comparison to Fish Creek Discussion and conclusions Literature cited
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  • 88
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-84/15
    In: CRREL Report, 84-15
    Description / Table of Contents: Measurements of meltwater pH from annual layers of South Pole firn and ice samples ranging in age from 40 to 2000 years B.P. show that precipitation at this remote site has a higher natural acidity than that expected from atmospheric equilibrium with CO2. The average pH of deaerated (CO2-free) samples was 5.64 + or - 0.08, while air-equilibrated samples averaged 5.37 + or - 0.008, a pH that is about a factor of two more acidic than the expected background pH of 5.65. The observed 'excess' acidity can be accounted for by natural SO4(2)- and NO(3)- levels in the samples probably originating from non-anthropogenic H2SO4 and HNO3. Because of the presence of these naturally occurring acids in South Pole precipitation, a pH of 5.4 is considered a more representative baseline reference pH for acid precipitation studies.
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    Pages: ii, 12 Seiten , Illustrationen
    Series Statement: CRREL Report 84-15
    Language: English
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  • 89
    Call number: ZSP-201-84/9
    In: CRREL Report, 84-9
    Description / Table of Contents: This report presents the results of the first phase of a test program designed to obtain a comprehensive understanding of the mechanical properties of multi-year sea ice from the Alaskan Beaufort Sea. In Phase I, 222 constant-strain-rate uni-axial compression tests were performed on ice samples from ten multi-year pressure ridges to examine the magnitude and variation of ice strength within and between pressure ridges. A limited number of constant-strain-rate compression and tension tests, constant-load compression tests, and conventional triaxial tests were also performed on ice samples from a multi-year floe to provide preliminary data for developing ice yield criteria and constitutive laws for multi-year sea ice. Data are presented on the strength, failure strain, and modulus of multi-year sea ice under different loading conditions. The statistical variation of ice strength within and between pressure ridges is examined, as well as the effects of ice temperature, porosity, structure, strain rate and confining pressure on the mechanical properties of multi-year sea ice.
    Type of Medium: Series available for loan
    Pages: v, 107 Seiten , Illustrationen
    Series Statement: CRREL Report 84-9
    Language: English
    Note: CONTENTS Abstract Preface Introduction Field Sampling Site selection and description Ice sampling procedures Shipping and storage of ice samples Testing Techniques Multi-year Pressure Ridge Tests Ice description Sampling scheme and test variables Uniaxial compressive strength Residual compressive strength Failure strains Initial tangent modulus Statistical Variations in Ice Strength Differences in strength above and below level ice Sources of the variation in strength Shape of the strength histograms Multi-year Floe Ice Tests Ice description Uniaxial compressive strength Constant-load compression tests Constant-strain-rate tension tests Triaxial tests Conclusions Literature Cited Appendix A: Structural profile of a multi-year pressure ridge core Appendix B: Ridge uniaxial compression test data Appendix C: Structural profile of the continuous multi-year floe core Appendix D: Multi-year floe test data
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  • 90
    Call number: ZSP-201-83/32
    In: CRREL Report, 83-32
    Description / Table of Contents: Ice forces on a bridge pier in the Ottauquechee River, in Quechee, Vermont, were measured by installing fourpanels-each capable of measuring forces in the normal and tangential direction - on both sides of a vertical V-shaped pier nose. The measured forces are presented for a short period during an ice run. After the ice run, the thickness and sizes of the ice floes were measured and the compressive strength of the ice was determined in the laboratory from the ice samples collected along the river banks. The water level measurements made at several locations along theriver are also presented for the period of the ice run.
    Type of Medium: Series available for loan
    Pages: ii, 8 Seiten , Illustrationen
    Series Statement: CRREL Report 83-32
    Language: English
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  • 91
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-85/9
    In: CRREL Report, 85-9
    Description / Table of Contents: Large temperature gradients applied to a snow cover drive water vapor upwards and result in rapid recrystallization of snow crystals. The same temperature gradients create gradients of air density that can cause flows of air through the snow cover. The formalism necessary to describe these flows I developed heroin an effort to include the convection of vapor in the understanding of snow metamorphism. The theory of convection through porous media is extended here to include the transport of water vapor, which is important because of its latent heat. Results are presented in terms of a Lewis number, defined as the ratio of thermal to mass diffusivities. For Lewis numbers greater than 1.0 phase change intensifies convection, and for Lewis numbers less than 1.0 phase change retards convection. Two boundary conditions of special interest in the study of snow, a constant heat flux bottom and a permeable top are investigated. Their influence on the transfer of heat is quantified, and it is found that heat transfer can be described as a linear function of the driving force for convection. Convection in sloped layers is quantified, and explained in a physically consistent manner. The effect of a permeable top on convection at low Rayleigh numbers is derived. Experiments are performed to measure the effects of convection on heat transfer through glass beads and snow. The model results using constant flux boundary conditions are confirmed by the experiments. Experiments show that convection can occur in snow, and that convection behaves in a manner consistent with our theoretical understanding of the phenomenon. Some uncertainty exists about the permeability and thermal conductivity of snow and hence it is uncertain if thermal convection would occur for a given temperature gradient, density and thickness. Also, for a given convective intensity, there is much uncertainty about how much the rate of snow metamorphism is increased.
    Type of Medium: Series available for loan
    Pages: vi, 70 Seiten , Illustrationen
    Series Statement: CRREL Report 85-9
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Snow metamorphism Mass transfer by diffusion in snow Heat transfer Background-porous media Structure of thermal convection Rayleigh number Onset problem Heat transfer attributable to thermal convection Layering and slope effects Studies of convection through snow Modeling Equation of motion Energy equation Finite difference methods Numerical solution Verification of the model Modeling results Effects of constant flux and permeable boundaries on convection in horizontal layers Effects of phase change on convection Convection in sloped layers Experiments Introduction Experimental apparatus Experimental results and discussion Glass beads Snow Applications and conclusions Onset of Benard convection in seasonal snow covers Applications to snow metamorphism Summary Recommendations Literature cited Appendix A: Derivation of fmite difference formulae Appendix B: Computer programs Appendix C: Sample calculations
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  • 92
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-85/10
    In: CRREL Report, 85-10
    Description / Table of Contents: Various methods of generating synthetic seismograms are reviewed and examples of recent applicatiors of the methods are cited. Body waves, surface waves, and normal modes are considered. The analytical methods reviewed include geometric ray theory, generalized ray theory (Cagniard-de Hoop method), asymptotic ray theory, reflectivity method, fullwave theory, and hybrid methods combining ray theory and mode theory. Two numerical methods, those of finite differences and finite elements, and a hybrid method combining finite differences with asymptotic ray theory are described Limitations on the application or validity of the various methods are stated.
    Type of Medium: Series available for loan
    Pages: v, 48 Seiten , Illustrationen
    Series Statement: CRREL Report 85-10
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Section 1. Introduction Section 2. Wave propagation in the earth Section 3. Body waves: ray theory and wave theory Geometric ray theory Wave theory Section 4. Surface waves Section 5. Normal modes Section 6. Finite-difference method Section 7. Finite-element method Section 8. Hybrid methods Section 9. Conclusion Literature cited
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  • 93
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-85/17
    In: CRREL Report, 85-17
    Description / Table of Contents: This report presents the results of tests of the ice friction coefficient carried out during the May 1984 expedition of the F.S. Polarstern off the coast of Labrador. The test surfaces were Inerta-160-coated steel plates and bare steel plates, hand roughened and sandblasted. The main findings of the studies were: 1) columnar and granularpea ice showed no significant differences in friction coefficient; 2) for columnar ice was independent of ice crystal orientation with respect to test surface; 3) was Independent of normal pressure applied on ice sample; 4) initially decreased with increasing relative velocity between the Ice sample and the test surface and reached a steady value at higher speeds; 5) Uk increased with increasing surface roughness; 6) a wetting surface exhibited a higher friction coefficient than a non-wetting surface of the same or even higher roughness average.
    Type of Medium: Series available for loan
    Pages: iv, 26 Seiten , Illustrationen
    Series Statement: CRREL Report 85-17
    Language: English
    Note: CONTENTS Abstract Preface Introduction Test procedure Test apparatus Test surfaces Ice samples Test program Results and discussion Effect of wear of ice sample Effect of normal pressure Effect of velocity, crystal orientation and surface conditions Results summary Comparison with laboratory study Recommendations on test apparatus Literature cited Appendix A : Test results
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  • 94
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-85/22
    In: CRREL Report, 85-22
    Description / Table of Contents: Tests in level ice on an idealized icebreaker bow in the shape of a simple wedge were conducted in the test basin. The horizontal and vertical forces on the wedge were measured, and floe size distribution in the wake of the wedge was observed. From the force measurements, the ice wedge/hull friction factor was calculated and found to be in general agreement with the friction factor measured in separate friction tests. The ice floe length and ice floe area measured in the current study were found to follow log-normal probability distributions defined by the length average L and area average A and corresponding standard deviations SL and SA. The results of these tests and other tests conducted at another facility showed that the ratios A/h2 and L/h (A =average floe area, L averagefloe length, h = ice thickness) were, for the same type of model ice, directly proportional to the parameter y/-yh. (a = ice bending strength, tj7= specific weight of water) and a/y, respectively, and independent of the velocity and ice strain modulus or ice characteristic* length. However, the coefficients of proportionality appear to depend upon the type of model ice used in the tests. The ratios Si/A were independent of o/yh but varied with the bow shape and the type of ice. The available field data are not sufficient for meaningful comparison with the laboratory results.
    Type of Medium: Series available for loan
    Pages: iv, 53 Seiten , Illustrationen
    Series Statement: CRREL Report 85-22
    Language: English
    Note: CONTENTS Abstract Preface Introduction Experimental set-up and conditions Results of wedge resistance measurements Results of floe size measurements Statistical analysis of data Comparison between model and full-scale data Conclusions and recommendations Literature cited Appendix A: Wedge tests-floe size measurements Appendix B: Wedge tests-histograms of floe length and floe area Appendix C: Cumulative frequency distributions for floe length and floe area
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  • 95
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-86/17
    In: CRREL Report, 86-17
    Description / Table of Contents: Rime icing and freezing precipitation are of concern to the radio and television broadcasting industry. This report contains the results of a study seeking to document the severity and extent of transmitter tower icing and related problems in the northeastern United States. Information was obtained via mail questionnaire and telephone interviews with 85 station owners and engineers concerning 118 different stations. Results show that television and FM broadcasters are seriously impacted by tower icing; however, AM operators are usually not affected by expected New England icing levels. Combined annual costs for icing protection and icing-related repairs averaged $121, $402 and $3066 for AM, FM and TV stations respectively. None of the AM stations polled employ any icing protection in the three northern states averaged 80%, indicating a significant concern for icing in that region. In contrast, the percentage of FM stations with icing protection was 63.5% for the southern New England states. The usage of guyed versus non-guyed towers was a poor indicator of icing costs. However, the factors of increasing mast height and mast top elevation are significant to increasing costs.
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    Pages: iv, 52 Seiten , Illustrationen
    Series Statement: CRREL Report 86-17
    Language: English
    Note: Contents Abstract Preface Introduction Background Types of accretions Problems caused by icing Prevention and shedding methods Results The survey Data presentation Discussion Survey response distribution Effect of icing protection on parameter averages Effect of tower type on parameter averages Moderate and more severe icing locations Relationship of climate, geography and topography to icing severity Total annual costs Conclusions Literature cited Appendix A: Tower icing survey Appendix B: Station summaries
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  • 96
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    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-87/4
    In: CRREL Report, 87-4
    Description / Table of Contents: In this report we present results of measurements of the crystalline structure and salinity characteristics of sea ice in Hebron Fiord and vicinity, Labrador. Structurally, the fiord ice was entirely first year and composed predominantly of congelation, columnar-type crystals. At most of the sampling sites the ice exhibited moderately to strongly aligned c-axes consistent with the inferred direction of near surface currents in the fiord. Generally diminished values of bulk salinity at five separate locations reflect the warm ice conditions encountered at the time of sampling (late May) and the effect of meltwater flushing in promoting loss of brine, vertically, from the ice sheet. Observations outside Hebron Fiord indicated the presence of only minor amounts of multiyear ice during the latter part of May.
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    Pages: iii, 25 Seiten , Illustrationen
    Series Statement: CRREL Report 87-4
    Language: English
    Note: Contents: Abstract Preface Introduction Sampling procedure Analytical techniques Salinities Crystal structure Results Salinity Crystal structure Brine layer spacing Incidental temperatures Conclusions Literature cited Appendix A: Vertical and horizontal thin section photographs of sea ice from various sites
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  • 97
    Call number: ZSP-201-87/2
    In: CRREL Report, 87-2
    Description / Table of Contents: This is the third in a series of four reports on the laboratory and field testing of a number of road and airfield subgrades, covering the laboratory repeated-load triaxial testing of five soils in the frozen and thawed states and analysis of the resulting resilient modulus measurements. The laboratory testing procedures allow simulation of the gradual increase in stiffnessfound in frost-susceptible soils after thawing. The resilient modulus is expressed in a nonlinear model in terms of the applied stresses, the soil moisture tension level (for unfrozen soil), the unfrozen water content (for frozen soil) and the dry density. The resilient modulus is about 10 GPa for the frozen material at temperatures in the range of -5° to -8° C. The decrease in modulus with increasing temperature was well-modeled in terms of the unfrozen water content. Upon thaw, the modulus dropped to about 100 MPa and generally increased with increasing confining stress and decreased with increasing principal stress ratio. The modulus also increased with the soil moisture tension level. The resilient Poisson's ratio did not appear to be a systematic function of any of the test variables.
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    Pages: iii, 36 Seiten , Illustrationen
    Series Statement: CRREL Report 87-2
    Language: English
    Note: CONTENTS Abstract Preface Introduction Test sections and materials Specimen preparation Test soils Asphalt concrete Laboratory testing Soil testing Waveforms of applied stress Asphalt concrete Data reduction and analysis Soil Asphalt concrete Results and discussion General Resilient modulus Summary Conclusions Literature cited Appendix A: Soil moisture tension versus water content for several test soils Appendix B: Tabulated results for all tests on frozen and thawed soils
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  • 98
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-86/14
    In: CRREL Report, 86-14
    Description / Table of Contents: Three methods for determining the frost susceptibility of soils are evaluated in this report. These methods are the U.S. Army Corps of Engineers frost design soil classification system, a moisture-tension/hydraulic-conductivity test, and a laboratory freeze-thaw test. The Corps method, which is based on particle size, soil classification, and a laboratory freezing test, was found to be useful for identifying frost-susceptibility. The moisture-hydraulic-conductivity test was found to be unacceptable because it required too much time and its results correlated poorly with field observations. The freeze-thaw test was determined to be the most accurate of the methods studied, including the freeze test that is a part of the Corps method. The freeze-thaw test is thoroughly described. It includes indexes of both frost-heave susceptibility (heave rate) and thaw-weakening susceptibility (CBR after thawing). It also accounts for the effects of freeze-thaw cycling and is completely automated to improve the repeatability of the test results. It is suggested that the freeze-thaw test considered as a replacement for the Corps freezing test.
    Type of Medium: Series available for loan
    Pages: v, 56 Seiten , Illustrationen
    Series Statement: CRREL Report 86-14
    Language: English
    Note: Contents Abstract Preface Introduction Description of the selected sites Corps of engineers frost design soil classification system Moisture-tension/hydraulic-conductivity tests Freezing test Validation Description of test sites and materials Sample preparation Results and analysis of laboratory tests Corps of engineers frost design soil classification system Moisture-tension/hydraulic-conductivity test Freezing test Discussion Conclusions Recommendations Literature cited Appendix A: Summary of frost-susceptibility tests on natural soil
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  • 99
    Call number: ZSP-201-87/3
    In: CRREL Report, 87-3
    Description / Table of Contents: This report describes the structural analysis of multi-year sea ice samples that were tested in the first phase of a program designed to obtain a comprehensive understanding of the mechanical properties of multi-year sea ice from the Alaskan Beaufort Sea. Each test specimen is classified into one of three major ice texture categories: granular, columnar, or a mixture of columnar and granular ice. The crystallographic orientation, percent columnar ice, and grain size are then evaluated for the granular and/or columnar ice in the sample. Test results are interpreted with respect to these parameters. The overall composition of multi-year ridges is also considered, based on the extensive field sampling that was done in the program
    Type of Medium: Series available for loan
    Pages: iii, 40 Seiten , Illustrationen
    Series Statement: CRREL Report 87-3
    Language: English
    Note: CONTENTS Abstract Preface Introduction Sample analysis Continuous multi-year ridge core Tested multi-year ridge ice samples Tested multi-year floe ice samples Ice description Uniaxial constant-strain-rate compression tests Uniaxial constant-load compression tests Uniaxial constant-strain-rate tension tests Triaxial constant-strain-rate compression test Conclusions Literature cited Appendix A: Multi-year ridge sample data Appendix B: Multi-year floe sample data
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  • 100
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-88/20
    In: CRREL Report, 88-20
    Description / Table of Contents: This study develops design criteria for a new sludge dewatering unit operation called a sludge freezing bed. This bed uses natural freeze-thaw to condition the sludge. The total depth of sludge that can be frozen, thawed and dewatered by this process in a year is the main criterion needed for design. Laboratory tests assessed the dewaterability of freeze-thaw conditioned water treatment plant sludge and both anaerobically and aerobically digested wastewater sludges at various depths. Mathematical models for predicting the design depth were developed; values for the input parameters to the models were obtained from the literature or from laboratory and pilot-scale experiments. The dewaterability tests indicated that the depth of sludge that can be applied is not limited by drainability. Up to 2.0 m of each sludge drained in minutes after freeze-thaw conditioning. Except for the aerobically digested sludge, the solids content after drainage is high enough to permit mechanical removal. The physical and thermal characteristics of frozen sludge were found to be equivalent to those of ice. An analysis of the freezing and thawing models reveals that the design of a freezing bed will depend on the duration and intensity of the freezing and thawing seasons.
    Type of Medium: Series available for loan
    Pages: v, 58 Seiten , Illustrationen
    Series Statement: CRREL Report 88-20
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Background Purpose Scope Literature review Fundamentals of freeze separation Applications of freeze separation technology Conclusions Concept development Background Site visits Final concept Dewaterability studies Sludge characteristics Specific resistance and capillary suction time Filtrate quality Drainage tests Drying tests Development of design models Basic energy balance relationship Development of freezing model Development of thawing model Other models Evaluation of sludge input parameters Frozen sludge density, ϱf Layer thickness, ϵ Settled solids fraction, θ Thermal conductivities, Kfs, Kss Latent heat of fusion, L Absorptance, α Freezing point, Tf Summary Evaluation of climatic input parameters Ambient air temperatures, Taf, Tat Insolation, I Convection coefficient, hc Use of models for design Freezing design depth Thawing design depth Validation Example Conclusions anid recommendations Literature cited Appendix A: Sludge freezing at the Salem, New Hampshire, Wastewater Treatment Plant
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