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  • Wuppertal : Wuppertal Institut für Klima, Umwelt, Energie  (1,294)
  • Uppsala
  • Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
  • English  (1,782)
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  • 1
    Call number: M 96.0114
    In: Rapporter och meddelanden / Sveriges Geologiska Undersökning
    Type of Medium: Monograph available for loan
    Pages: 30 S.
    ISBN: 9171585273
    ISSN: 0349-2176
    Series Statement: Rapporter och meddelanden / Sveriges Geologiska Undersökning nr. 76
    Classification:
    Regional Geology
    Language: English
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  • 2
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-83/30
    In: CRREL Report, 83-30
    Description / Table of Contents: Ice sheets are formed and retained in several ways in nature, and an understanding of these factors is needed before most structures can be successfully applied. Many ice sheet retention structures float and are somewhat flexible; others are fixed and rigid or semirigid. An example of the former is the Lake Erie ice boom and of the latter, the Montreal ice control structure. Ice sheet retention technology is changing. The use of timber cribs is gradually but not totally giving way to sheet steel pilings and concrete cells. New structures and applications are being tried but with caution. Ice-hydraulic analyses are helpful in predicting the effects of structures and channel modifications on ice cover formation and retention. Often, varying the flow rate in a particular system at the proper time will make the difference between whether a structure will or will not retain ice. The structure, however, invariably adds reliability to the sheet ice retention process.
    Type of Medium: Series available for loan
    Pages: iv, 39 Seiten , Illustrationen , 1 Beilage
    Series Statement: CRREL Report 83-30
    Language: English
    Note: Contents Abstract Preface Introduction Natural ice sheets Choosing an ice control structure Flexible structures Ice booms Frazil collector lines Fence booms Rigid or semirigid structures Pier-mounted booms Stone groins Artificial islands Removable gravity structures Timber cribs Weirs Pilings and dolphins Structures built for other purposes Hydroelectric dams Wicket dams Light piers and towers Bridge piers Breakwaters Ice control not using Structures Channel improvements Ice sheet tying Ice sheet bridges Conclusions Literature cited Appendix A: Ice control structure
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  • 3
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-82/31
    In: CRREL Report, 82-31
    Description / Table of Contents: Information on sea ice conditions in the Bering Strait and the icefoot formation around Fairway Rock, located in the strait, is presented. Cross-sectional profiles of Fairway Rock and the relief of the icefoot are given along with theoretical analyses of the possible forces active during icefoot formation. It is shown that the ice cover most likely fails in flexure as opposed to crushing or buckling, as the former requires less force. Field observations reveal that the Fairway Rock icefoot is massive, with ridges up to 15 m high, a seaward face only 20 degrees from vertical, and interior ridge slopes averaging 33 degrees. The icefoot is believed to be grounded and its width ranges from less than 10 to over 100 m.
    Type of Medium: Series available for loan
    Pages: 44 Seiten , Illustrationen
    Series Statement: CRREL Report 82-31
    Language: English
    Note: CONTENTS Abstract Preface Introduction Bering Strait Field reconnaissance Estimation of ice forces on Fairway Rock 1. Creep deformation 2. Crushing failure 3. Flexural failure 4. Forces required to form floating or grounded pressure ridges along therock or to pile ice on the beaches 5. Buckling failure Driving forces Angle of internal friction of sea ice Summary Literature cited Appendix A: April 1982 field observations at Fairway Rock
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  • 4
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-82/32
    In: CRREL Report, 82-32
    Description / Table of Contents: Low-frequency (10 Hz) volcanic earthquakes originate at a wide range of depths and occur before, during, and after magmatic eruptions. The characteristics of these earthquakes suggest that they are not typical tectonic events. Physically analogous processes occur in hydraulic fracturing of rock formations, low-frequency icequakes in temperate glaciers, and autoresonance in hydroelectric power stations. We propose that unsteady fluid flow in volcanic conduits is the common source mechanism of low-frequency volcanic earthquakes (tremor). The fluid dynamic source mechanism explains low-frequency earthquakes of arbitrary duration, magnitude, and depth of origin, as unsteady flow is independent of physical properties of the fluid and conduit. Fluid transients occur in both low-viscosity gases and high-viscosity liquids. A fluid transient analysis can be formulated as generally as is warranted by knowledge of the composition and physical properties of the fluid, material properties, geometry and roughness of the conduit, and boundary conditions. To demonstrate the analytical potential of the fluid dynamic theory, we consider a single-phase fluid, a melt of Mount Hood andeside at 1250 deg C, in which significant pressure and velocity variations occur only in the longitudinal direction.
    Type of Medium: Series available for loan
    Pages: 15 Seiten , Illustrationen
    Series Statement: CRREL Report 82-32
    Language: English
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  • 5
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-82/34
    In: CRREL Report, 82-34
    Description / Table of Contents: The ice discharge through an opening in an ice control structure was documented to be a function of the floe size, ice type, ice floe conditions and vessel direction. The model data for the average ice discharge per vessel transit scaled to prototype values compared favorably with data taken at the St. Marys River ice control structure (ICS). The model results of the force measurements were also consistent with data taken at the St. Marys ICS. The dynamic loading conditions were independent of vessel direction. The dynamic loading to the structure using 3 types of ice (plastic, natural and urea-doped) showed a considerable difference in their means and standard deviations. The urea-doped ice was evaluated for dynamic loading conditions, and reasonable peak values of 3 to 5 times the mean load at each measuring position were recorded, independent of vessel direction. It appears that synthetic random ice floes may be used in model studies where ice discharge through an opening in a structure needs to be documented. This study shows the synthetic random ice floe discharge to fall reasonably within the values obtained for natural ice discharge for both rafted and non-rafted ice fields above the ICS. However, the question of whether synthetic ice can be used for analyzing force distributions and dynamic force loading criteria cannot be fully answered at this time because the load distributions of the synthetic and natural floes appear to differ.
    Type of Medium: Series available for loan
    Pages: 68 Seiten , Illustrationen
    Series Statement: CRREL Report 82-34
    Language: English
    Note: CONTENTS Abstract Preface Introduction Scope of work Ice discharge from Lake Huron into St. Clair River Water velocity profiles at Port Huron Ice conditions Physical model Basis for selection Description Instrumentation Model ice control structure Open water calibration Open water tests Experimental procedures and techniques Ice cover calibration Ice control structure orientation Analysis of ice discharge due to ship transits Natural ice Synthetic ice Forces on the ice control structure Static measurements Dynamic force measurements Potential additional shear stresses Anticipated ice conditions with ICS Conclusions Literature cited Appendix A. Application of model results Appendix B. Suggested additional studies Appendix C. Derivation of ice discharge
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  • 6
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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.
    Type of Medium: Series available for loan
    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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  • 7
    Call number: ZSP-201-83/22
    In: CRREL Report, 83-22
    Description / Table of Contents: A new experimental method for measuring the soil-water diffusivity of frozen soil under isothermal conditions is introduced. The theoretical justification of the method is presented and the feasibility of the method is demonstrated by experiments conducted using marine-deposited clay. The measured values of the soil-water diffusivity are found comparable to reported experimental data.
    Type of Medium: Series available for loan
    Pages: 13 Seiten , Illustrationen
    Series Statement: CRREL Report 83-22
    Language: English
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  • 8
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    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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  • 9
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    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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  • 10
    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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  • 11
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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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  • 12
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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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.
    Type of Medium: Series available for loan
    Pages: iii, 16 Seiten , Illustrationen
    Series Statement: CRREL Report 83-6
    Language: English
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  • 13
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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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.
    Type of Medium: Series available for loan
    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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  • 14
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-83/2
    In: CRREL Report, 83-2
    Description / Table of Contents: A numerical model of rime ice accretion on an arbitrary two-dimensional airfoil is presented. The physics of the model are described and results are presented that demonstrate, by comparison with other theoretical data and experimental data, that the model predictions are believable. Results are also presented that illustrate the capability of the model to handle time-dependent rime ice accretion, taking into account the feedback between the ice accretion and the airflow and droplet trajectory fields.
    Type of Medium: Series available for loan
    Pages: vi, 81 Seiten , Illustrationen
    Series Statement: CRREL Report 83-2
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Methodology Potential flow around an arbitrary airfoil Incompressible velocity field Droplet trajectory equation Computational procedure for trajectories Determining the point of impact Calculation of collision efficiencies Accreting an ice layer Determining the accuracy of the flow field Determining the accuracy of the trajectories Results and discussion Comparing results with and without the history term Collision efficiency of NACA 0015 airfoil at 8° attack angle Time-dependent accretion on NACA 0015 airfoil at 8° attack angle Time-dependent accretion on NACA 0015 airfoil at 0° attack angle Conclusions and recommendations Literature cited Appendix A : Sample input Appendix B: Sample output Appendix C : Program listing
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  • 15
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-83/1
    In: CRREL Report, 83-1
    Description / Table of Contents: Roof snow load case studies gathered throughout the United States over a three-year period are analyzed. The objective of the analysis is to determine a relationship between the snow load on the ground and the corresponding uniform snow load on flat and sloped roofs. The main parameters considered are the thermal characteristics of the roof, the roof slope and the exposure of the structure. Exposure has the strongest effect on the ratio of ground to roof snow loads. Comparisons are made with existing and proposed building codes and standards.
    Type of Medium: Series available for loan
    Pages: iv, 47 Seiten , Illustrationen
    Series Statement: CRREL Report 83-1
    Language: English
    Note: CONTENTS Abstract Preface Metric conversion table Introduction Data base Conversion factor Ground load effects Exposure effects Thermal effects Slope effects Expected value relationship Comparison with existing codes and standards Comparison with relationships proposed in new ANSI standard Summary and conclusions Literature cited Appendix A. Roof snow load case history reports Appendix B. Roofs in the snow load case study data base Appendix C. Ground and roof snow load data Appendix D. Conversion factors from the 1982 ANSI standard
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  • 16
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-84/3
    In: CRREL Report, 84-3
    Description / Table of Contents: The results of resistance tests in level ice and broken ice channels are presented for two models of the WTGB 140-fticebreaker at scales of 1:10 and 1:24, respectively. No scale effect on the resistance in level ice could be detected between the two models. From the test results an empirical predictor equation for the full scale ice resistance is derived. Predicted resistance is compared against, and found to be 25 to 40% larger than, available full-scale values estimated from thrust measurements during full-scale trials of the Great Lakes icebreaker Katmai Bay.
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    Pages: v, 25 Seiten , Illustrationen
    Series Statement: CRREL Report 84-3
    Language: English
    Note: COTENTS Abstract Preface Nomenclature Introduction Model characteristics and test conditions Ice-hull coefficient of friction Measurements of ice properties Experimental procedures Data acquisition system Test program and procedures for 1:10 model Test program and procedures for 1:24 model Analysis of test results Comparison of test results between 1:10 and 1:24 models Analysis of tests in broken or brash-filled ice channels Analysis of tests in level ice Full-scale prediction of level ice resistance Conclusions Literature cited
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  • 17
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    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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  • 18
    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.
    Type of Medium: Series available for loan
    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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  • 19
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    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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  • 20
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-84/8
    In: CRREL Report, 84-8
    Description / Table of Contents: This report describes the equipment and procedures that were used for acquiring, preparing and testing samples of multi-year sea ice. Techniques and procedures are discussed for testing ice samples in compression and tension at constant strain rates and constant loads, as well as in a conventional triaxial cell. A detailed account is given of the application and measurement of forces and dispiacements on the ice test specimens under these different loading conditions.
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    Pages: iv, 43 Seiten , Illustrationen
    Series Statement: CRREL Report 84-8
    Language: English
    Note: CONTENTS Abstract Preface Introduction Test material and test specimens Test material Required dimensions for test specimens Acquisition and preparation of specimens Field core sampling Specimen preparation in the laboratory Application of forces and displacements to uniaxial specimens Compression Tension Squareness imperfections Loading devices Universal testing machine Gas actuator for constant load Weight-and-pulley system for constant tension Equipment for triaxial tests Measurement of force and displacement Force Displacement Readouts and recorders Literature cited Appendix A: Phenolic-resin end caps Appendix B: Compliant platens Appendix C: Theoretical factor for converting overall strain to gauge-length strain indumbbell specimens Appci dix D: Items developed but not used in Phase I Appendix E: Use of the Brazil test
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  • 21
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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.
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    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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  • 22
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    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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  • 23
    Call number: ZSP-201-85/15
    In: CRREL Report, 85-15
    Description / Table of Contents: A method for the analysis of TNT, RDX and HMX explosives in soils and sediments has been developed. It consists of methanol extraction followed by reversed-phase high performance liquid chromatography using 10% acetonitrile/40% methanol/50% water as the eluant. This method was used to study the effect of various drying techniques upon the recovery of TNT, RDX, and HMX from soil and sediment samples contaminated with high (%) and low (micron g/g) levels of these explosives. For highly contaminated samples, complete recovery of TNT and RDX was obtained using freeze drying while air drying at room temperature resulted in greater than 90% recovery for both explosives. Other techniques, such as oven drying at 105 C, oven drying at 45 C, microwave oven drying, and drying under infrared lamps, all resulted in greater losses, with TNT and RDX recoveries ranging from 76 to 90%. Drying losses were not due to simple volatilization containing low levels of TNT, RDX and HMX, recoveries of all three explosives were quantitative for all the above drying techniques.
    Type of Medium: Series available for loan
    Pages: iii, 15 Seiten , Illustrationen
    Series Statement: CRREL Report 85-15
    Language: English
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  • 24
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-86/7
    In: CRREL Report, 86-7
    Description / Table of Contents: Nitrogen control in the form of ammonia removal or conversion is required, or will be required, for a significant number of military wastewater treatment systems. This reportpresents a summary of engineering criteria for those processes in most common use at military facilities in the cold regions. These processes include: trickling filters, treatmentponds, rotating biological contactors (RBC) and activated sludge. A design example is presented for each case. All four processes can achieve significant levels of ammonia removalor conversion. If ammonia discharge limits are 0.5 mg/L or less it may be necessary to use the activated sludge process. Trickling filters or RBC units are recommended for higher(〉 1 mgIL) discharge limits. Pond systems are suitable for seasonal ammonia removal incold climates.
    Type of Medium: Series available for loan
    Pages: iv, 29 Seiten , Illustrationen
    Series Statement: CRREL Report 86-7
    Language: English
    Note: CONTENTS Abstract Preface Introduction Background and theory Trickling filters Introduction Design procedure Design example Winter operations Pond systems Introduction Design procedure Design example Winter operations Rotating biological contactors Introduction Design procedure Design example Winter operations Activated sludge systems Introduction Design procedure Design example Winter operations Comparison of alternatives Conclusions Literature cited
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  • 25
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    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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  • 26
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-88/2
    In: CRREL Report, 88-2
    Description / Table of Contents: While many materials undergo phase change at a fixed temperature, soil systems exhibit a definite zone of phase change. The variation of unfrozen water with temperature causes a soil system to freeze of thaw over a finite temperature range. Exact and approximate solutions are given for conduction phase change of plane layers of soil with unfrozen water contents that vary linearly and quadratically with temperature. The temperature and phase change depths were found to vary significantly from those predicted for the constant-temperature or Neumann problem. The thermal conductivity and specific heat of the soil within the mushy zone varied as a function of unfrozen water content. It was found that the effect of specific heat is negligible, while the effect of variable thermal conductivity can be accounted for by a proper choice of thermal properties used in the constant-thermal-property solution.
    Type of Medium: Series available for loan
    Pages: v, 30 Seiten , Illustrationen
    Series Statement: CRREL Report 88-2
    Language: English
    Note: CONTENTS Abstract Nomenclature Preface Introduction Basic equations Two-zone problems Linear unfrozen water function Quadratic unfrozen water function Three-zone problems Linear unfrozen water function Quadratic unfrozen water function Conclusions Literature cited Appendix A: Derivation of the mushy zone equation Appendix B: Solution of the two-zone problem with a linear t and variable thermal properties
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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-201-88/11
    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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  • 28
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-88/5
    In: CRREL Report, 88-5
    Description / Table of Contents: This report describes the structural analysis of multi-year sea ice samples that were tested in the second 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 considered, based on the extensive field sampling that was done in the program. The effect of sample orientation on the results is also discussed.
    Type of Medium: Series available for loan
    Pages: iii, 32 Seiten , Illustrationen
    Series Statement: CRREL Report 88-5
    Language: English
    Note: CONTENTS Abstract Preface Introduction Sample analysis Continuous multi-year ridge core Tested multi-year ridge ice samples Unconfined constant-strain-rate compression tests Confined constant-strain-rate compression tests Uniaxial constant-strain-rate tension tests Discussion Conclusion Literature cited Appendix A: Multi-year ridge sample data
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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-201-85/22
    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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  • 30
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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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  • 31
    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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  • 32
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    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.
    Type of Medium: Series available for loan
    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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  • 33
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-92/17
    In: CRREL Report, 92-17
    Description / Table of Contents: The CRREL Instrumented Vehicle (CIV), shear annulus, direct shear, andtriaxial compression devices were used to characterize the strength ofthawed and thawing soil. These strength values can be used in simpletraction models to predict the tractive performance of vehicles. Strength was evaluated in terms of the parameters c' and Φ' based on the Mohr-Coulomb failure criterion. It is proposed here that an instrumented vehicle is best suited for terrain characterization for mobility studies because the conditions created by a tire slipping on a soil surface are exactly duplicated. The c' and Φ' values from the shear annulus were found to overpredict traction because of the low normal stress applied by the annulus and the curved nature of the failure envelope. Of all the tests, the direct shear test yielded the highest Φ' value, most likely because the test was run at a slow deformation rate under drained conditions. The triaxial test results were the most similar to those from the vehicle. All test methods show Φ' increasingwith soil moisture up to the liquid limit of the soil and then decreasing. As measured with the vehicle, was also found to be strongly influenced by the thaw depth.
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    Pages: 17 Seiten , Illustrationen
    Series Statement: CRREL Report 92-17
    Language: English
    Note: CONTENTS Introduction Objective Background Strength measurement techniques Triaxial compression Direct shear Shear annulus device CRREL Instrumented Vehicle Discussion Comparison of methods Influence of soil conditions Traction prediction Conclusions References Abstract
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  • 34
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    Call number: ZSP-201-93/3
    In: CRREL Report, 93-3
    Description / Table of Contents: Results are presented of a study to determine appropriate methods of flow modification for mitigating ice jam formation in navigable rivers. Based on a review of alternative methods for flow modification, it is concluded that for many rivers, especially large ones, the most appropriate method involves controlled ice-cover formation through the regulation of river flow. Flow discharge and stages would be regulated by controlling the flow releases from reservoirs and flow stages at river dams, such that optimal flow conditions prevail for rapid formation, and subsequent maintenance, of an accumulation ice cover over river reaches in which potentially large amounts of frazil ice may grow. Accumulation covers would be formed of frazil ice pans and floes and, if appropriate, broken ice conveyed from upstream. Existing dams, augmented where needed by navigable ice booms, could serve as retention structures for the development of accumulation covers. A preliminary indication of the feasibility of this method for controlling ice-cover formation on stage-regulated pools of the Ohio River is assessed through the use of a numerical model that simulates ice-cover formation from frazil ice. It is found that this approach holds promise for mitigating jam occurrence, although its implementation necessarily entails management of flow through major portions of the Ohio River. The results of the study are, to a limited extent, generalized to other rivers.
    Type of Medium: Series available for loan
    Pages: v, 58 Seiten , Illustrationen
    Series Statement: CRREL Report 93-3
    Language: English
    Note: CONTENTS Preface Nomenclature Introduction Background Scope of the study Control of river ice formation Control methods Controlled ice-cover formation for the upper Ohio River Numerical simulation of ice-cover formation Flow profile Water temperature variation Frazil ice growth Ice-cover progression Thermal growth of ice cover Numerical results Illustration of simulated ice-:over formation Ice-cover formation in the Hannibal and Montgomery pools Generalized results Conclusions and recommendations Literature cited Appendix A: Expression for coefficients Appendix B: Listing of computer program
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  • 35
    Call number: ZSP-201-94/12
    In: CRREL Report, 94-12
    Description / Table of Contents: Subsurface radar was used to profile ice and snow conditions on the Ross Ice Shelf at McMurdo Station, Antarctica, during mid-January 1993. Deconvolution and migration were often used to improve vertical resolution and spatial imaging. Profiles at a pulse center frequency of 400 MHz along the 3.2-km-long Pegasus ice runway show many low-density horizons above 9 m depth that are up to 30 m long. They are associated with air bubbles included during refreezing of meltwater and are interpreted as layers between a few and tens of centimeters thick. There is a strong reflecting horizon at about 9 m depth that is probably from brine intrusion as it is continuous with the intrusion into the snow to the east. Diffraction asymptotes give a dielectric constant near 3.2 for material above the brine level, a value that implies near-solid ice. Profiles at 100 MHz along the road between Pegasus runway and Williams Field in the accumulation zone show snow features such as layer deformation and intrusive brine layers that both abruptly and gradually change in depth. A single profile at a relic solid waste dump at Williams Field detected buried debris and ice within the upper 7 m. A survey of a suspected fuel spill shows some local disturbances near the center, but no excavation was done to verify the findings. Profiles traversing the sewage sumps at Williams Field outline the extent of the sewage deposition, and give depths to contaminated snow that closely agree with observation. Despite variability in dielectric properties, single-layer migration effectively improves the resolution of subsurface conditions. Recommendations are made for future surveys.
    Type of Medium: Series available for loan
    Pages: iv, 29 Seiten , Illustrationen
    Series Statement: CRREL Report 94-12
    Language: English
    Note: CONTENTS Preface Introduction Radar equipment General operation Antennas Waveforms and phase polarity Antenna directivity Field procedures and data processing Field procedures Data recording Data processing Site location Results Pegasus runway Access road from Williams Field to Pegasus runway Williams Field Summary and conclusions Literature cited Appendix A: Airborne profile of a portion of the access road Abstract
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  • 36
    Call number: ZSP-201-93/11
    In: CRREL Report, 93-11
    Description / Table of Contents: A laboratory study of the behavior of snow under shock wave loading and unloading conditions was conducted using a 200-mm-diameter gas gun to generate loading waves in snow samples with initial densities of 100 to 520 kg m-3 at temperatures of -2 to -23 deg C. Stress levels were 2 to 40 MPa. The response of snow to shock wave loading was measured as a function of distance from the impact plane using embedded stress gauges. Large impedance differences between snow and the stress gauges produced complex stress histories. A finite element model, along with a simple analytical model of the experiment, was used to interpret the stress histories. Snow deformation was not affected by initial temperature, but was found to be rate dependent. The initial density of the snow determined its pressure-deformation path. The pressure needed to compact snow to a specific final density increases with decreasing initial density. The release moduli increased nonlinearly from 50 MPa at a snow pressure of about 15 MPa to 2700 MPa at a snow pressure of about 40 MPa.
    Type of Medium: Series available for loan
    Pages: iii, 150 Seiten , Illustrationen
    Series Statement: CRREL Report 93-11
    Language: English
    Note: CONTENTS Preface Introduction Experimental equipment and methods Gas gun Snow target assembly Data acquisition Experimental procedure Measured data Stress histories Snow characterization Data analysis Recommendations Experimental methods Experimental needs Summary Literature cited Appendix A : Stress-time data plots Appendix B: Tabulated stress-time data Abstract
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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-201-76/41
    In: CRREL Report, 76-41
    Description / Table of Contents: Eight Geoceiver stations were established and suitably marked along or near the crestiline of the Greenland ice sheet during GISP field operations from 1971 to 1975. At one of these stations, DYE-3, repeated Geoceiver positions indicate an ice velocity of 12.7 m.yr on an azimuth of approximately 60 degrees. Data from the International Greenland Glaciological Expedition (EGIG) surveys show that ice flow in the vicinity of Crete is radiating outward from a dome to the south. Two independent calculations of the state of equilibrium at Crete indicate ice sheet thinning rates of 0.25 to 0.37 m/yr, while direct measurement of elevation change by EGIG indicates an ice sheet thickening rate of difference of 0.06 m/yr. Resolution of these differences must await further geophysical work and deep drilling in the ice sheet.
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    Pages: iii, 13 Seiten , Illustrationen
    Series Statement: CRREL Report 76-41
    Language: English
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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-201-76/44
    In: CRREL Report, 76-44
    Description / Table of Contents: The deformation of wet snow is explained in terms of the thermodynamics of the three phases of water. When deformation by particle rearrangement is fully developed, deformation can occur most rapidly by melting at the particle contacts. The rate of deformation is highly sensitive to the liquid water content, ionic impurity content, particle contact area, and stress level. A model of the hydrostatic deformation of wet snow is constructed, and examples of the deformation of wet snow are given for a variety of conditions. These results are in agreement with existing experimental evidence. The model accurately simulates the transient nature of the deformation and the effect of water content on the quasi-stable density of wet snow subjected to a constant stress.
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    Pages: iv, 9 Seiten , Illustrationen
    Series Statement: CRREL Report 76-44
    Language: English
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  • 39
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    Call number: ZSP-201-76/32
    In: CRREL Report, 76-31
    Description / Table of Contents: Four large grounded multi-year shear ridge formations were found in the grounded ice subzone of the fast ice zone near the Harrison Bay/Prudhoe Bay area of Alaska. A 166-m-long cross section of one of these formations was obtained by leveling and sonar measurements. These measurements revealed that the maximum ridge height was 12.6 m and that the formation was grounded in 17-18 m of water. The salinity, temperature, brine volume and density of the ice were determined on samples obtained by coring. The physical characteristics of the formations as observed in satellite, SLAR and aerial imagery indicate that these formations have not moved between the time of their formation in the fall of 1974 and August of 1976. Evidence of significant aeolian debris discoloring the ice is discussed.
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    Pages: iv, 27 Seiten , Illustrationen
    Series Statement: CRREL Report 76-32
    Language: English
    Note: Contents Abstract Preface Introduction Background Fast ice study area Results and discussion Literature cited
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  • 40
    Call number: ZSP-201-76/31
    In: CRREL Report, 76-31
    Description / Table of Contents: Sections in the Connecticut River where ice jam potential is high were identified through the use of low-altitude black and white photographs taken during low-flow, ice-free conditions. The hydraulics and mechanics of ice jam initiation were investigated in the river reach where these sections were identified. Certain areas were found in the river that had a high susceptibility to ice clogging, but this high potential decreased with increasing discharge because of the improved surface conveyance of the ice through the reach. The stability of ice floes was established along the channel, but the floes generally became unstable as the flow increased. This was calculated by using a Froude number criterion. Grounding locations for ice became evident when the critical Froude number was zero for a given thickness and water depth. No single factor was determined to be responsible for initiating the ice jams in the Connecticut River at Windsor. Apparently there existed a multitude of interacting conditions: surface constrictions, possible high backwater conditions from the Brattleboro Dam, a solid ice cover in the backwater of the Brattleboro Dam that prevented ice transport from the Windsor area, deep pools followed by shallow depth sections upstream of bridge piers, a greater ice thickness accumulation of fragmented floes than would result if a uniform cover could be established in the same reach, and the diurnal fluctuation of river stage casued by the release of water at Wilder Dam.
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    Pages: vi, 39 Seiten , Illustrationen
    Series Statement: CRREL Report 76-31
    Language: English
    Note: CONTENTS Abstract Preface Summary Conversion factors: U.S. customary to metric units of measurement Introduction Testsite Aerial photography Channel morphology — Interpretation of aerial photographs Ground surveys Hydraulic analysis Analysis of ice jam locations Winter field observations Conclusions Literature cited Appendix: Locations and plots of cross sections from Sumner Falls to Chase Island, Connecticut River
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  • 41
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    Call number: ZSP-201-76/42
    In: CRREL Report, 76-42
    Description / Table of Contents: A study of arching of mixed, square fragmented ice floes at an opening in an ice boom is documented, using results from a model study in which two sizes of plastic blocks represented real ice. A power function, relating the upstream ice concentration to the ratio of a characteristic block dimension to the gap opening, is found adequate to distinguish between arching and nonarching events for block mixtures of two component sizes. It is demonstrated that when the respective total areas of the two block components are nearly equal, a minimum ice concentration initiates an arch across the opening. As the mixture of two sizes of blocks approaches a uniform (one-sized) mixture, a higher concentration of ice is needed to initiate the arch. When the ratio of the block dimension to the gap opening is equal to or less than 0.10, arching of the fragmented ice is not possible, even when the upstream ice discharge exceeds the maximum discharge of ice through a gap opening. The distribution of fragmented ice areas is an important parameter in establishing the minimum size of opening at which an ice boom will retain its arching capability.
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    Pages: iv, 17 Seiten , Illustrationen
    Series Statement: CRREL Report 76-42
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  • 42
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    Call number: ZSP-201-76/43
    In: CRREL Report, 76-43
    Description / Table of Contents: Ice fog generated at the Eielson AFB power plant cooling pond contributes heavily to the total ice fog problem on the base. Several methods for ice fog suppression were studied and two techniques were tested experimentally. Experiments were also conducted to determine the magnitude of the various modes of heat transfer within the pond's microclimate. Values of evaporative and radiative heat loss during ice fog are presented. Ice cover is shown to be an effective ice fog suppression technique. Monomolecular films are also shown to be effective and offer some unique advantages, such as ease of application and low overall cost. The heat normally lost to evaporation must be dissipated by other means during suppression. With the ice cover technique this is accomplished by melting the ice cover. During suppression with monomolecular films, the heat must be dissipated by increasing radiative and convective losses. The simplicity of application of monomolecular films, along with their lower cost, combine to make this technique attractive; however, the lower pond temperatures and increased suppression effectiveness weigh heavily in favor of the ice-cover technique.
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    Pages: viii, 86 Seiten , Illustrationen
    Series Statement: CRREL Report 76-43
    Language: English
    Note: CONTENTS Abstract Preface List of symbols Conversion factors: U.S. customary to metric units of measurement Introduction Section I. Ice fog Section II. Evaporation Bowen's equation Evaporation equation Evaporation measurements during ice fog conditions Evaporation measurements at Eielson Power Plant cooling pond Data analysis Section Ill. Radiation during ice fog Brunt's equation Ångström equation Elsasser's equation Cloud cover Reflection Field experimental results Analysis of experimental results Radiation equations for ice fog Transmissivity of ice fog Radiation model Wind effect Summary Section IV. Convection Convective heat transfer theory Rotem and Claassen equation Kay's approach Russian approach Analysis Heat budget at the surface Conclusions Section V. Ice fog suppression techniques Fans Injection wells Latent heat storage Monomolecular films Use of heated water from the cooling pond Section VI. Latent heat storage experiments Freezing rates Cooling pond Ice building Ice growth rate -maximum system limitation Evaporation heat loss -maximum Realistic growth rate Ice building techniques Ice volume measurements Melting experiments Ice fog suppression considerations Experimental results Section VII. Recommendations and conclusions Hexadecanol studies Injection well suppression Latent heat storage suppression Comparison of approaches Measurements of evaporation Measurements of radiation loss Convective heat losses Ice fog suppression Selected bibliography Appendix A. Convective heat transfer coefficient from water to ice and from ice to air
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  • 43
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    Call number: ZSP-201-79/11
    In: CRREL Report, 79-11
    Description / Table of Contents: A theory of the optical properties of snow in the 2-20 region of the infrared has been developed. Using this theory it is possible to predict the absorption and scattering coefficients and the emissivity of snow, as a function of the snow parameters of grain size and density, for densities between 0.17 and 0.4 g/cm3. The absorption and scattering coefficients are linearly related to the density and inversely related to the average grain size. The emissivity is independent of grain size and exhibits only a weak dependence upon density.
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    Pages: iii, 9 Seiten , Illustrationen
    Series Statement: CRREL Report 79-11
    Language: English
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  • 44
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    Call number: ZSP-201-79/10
    In: CRREL Report, 79-10
    Description / Table of Contents: Ice cores from Byrd Station and Little America V have been used to test an ultrasonic technique for evaluating crystal anisotropy in the Antarctic Ice Sheet. P-wave velocities measured parallel and perpendicular to the vertical axes of cores from the 2164-m-thick ice sheet at Byrd Station have yielded results in excellent agreement with the observed c-axis fabric profile and with the in-situ P-wave velocity profile measured parallel to the bore hole axis. Velocity differences in excess of 140 m/s for core samples from deeper than 1300 m attest to the strong single pole clustering of crystallographic c-axes about the vertical, especially in the zone from 1300-1800 m. Such oriented structure is compatible only with strong horizontal shearing in this zone. The existence in an ice sheet of widespread shearing several hundred meters above its bed raises serious questions as to the validity of current concepts of the flow of large ice masses that tend to gloss over or ignore crystal alignments of this magnitude.
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    Pages: IV, 16 Seiten , Illustrationen
    Series Statement: CRREL Report 79-10
    Language: English
    Note: CONTENTS Abstract Preface Introduction Laboratory measurements Sample sources Ultrasonic velocity measurements Effects of inclined drilling at Byrd Station Results Byrd Station Little America V Summary and conclusions Literature cited
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  • 45
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-79/12
    In: CRREL Report, 79-12
    Description / Table of Contents: An analysis of a point source bubbler system used to induce local melting of an ice cover is presented. The analysis leads to a numerical simulation programmed in FORTRAN which may be used to predict the effectiveness of such systems. An example application is presented using a typical record of average daily air temperatures. The FORTRAN program for the point source simulation as well as a FORTRAN program for line source systems are included in the Appendix.
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    Pages: iii, 12 Seiten , Illustrationen
    Series Statement: CRREL Report 79-12
    Language: English
    Note: CONTENTS Abstract Preface Introduction Outline of analysis Plume analysis Heat transfer analysis Temperature of impinging plume Heat transfer coefficient Melting of the ice cover Simulation example Thermal reserve analysis Literature cited Appendix
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  • 46
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    Call number: ZSP-201-79/13
    In: CRREL Report, 79-13
    Description / Table of Contents: Heat transfer in turbulent flow was measured in a rectangular channel with a width of 0.254 m and a flow depth of 0.0254 m. Correlations between the Nusselt and Reynolds numbers are given for a range of 3020 Re 22360. A Prandtl number range of 9.90 or = Pr or = 12.28 for water was used in the tests. The results are compared with those of other investigations and show that some well-known correlations underpredict the heat transfer by about 35%.
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    Pages: ii, 5 Seiten , Illustrationen
    Series Statement: CRREL Report 79-13
    Language: English
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  • 47
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    Call number: ZSP-201-79/14
    In: CRREL Report, 79-14
    Description / Table of Contents: Solid ice growth rates due to the presence of frazil slush beneath the ice cover have been shown to be greater than the so-called static growth. The frazil slush reduces the effective heat of ice solidification and the frazil particles freeze into the interstitial water. Numerical schemes are presented which clearly show the effect of frazil ice porosity on ice cover growth rates and the numerical model using air temperature as the major input is compared with field data on ice thickness in a small river laden with frazil ice beneath its cover.
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    Pages: ii, 4 Seiten , Illustrationen
    Series Statement: CRREL Report 79-14
    Language: English
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  • 48
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-79/15
    In: CRREL Report, 79-15
    Description / Table of Contents: This report discusses the application of several modern geophysical techniques to groundwater exploration in areas in permafrost. These methods utilize the principles of magnetic induction and radiowave surface impedance in the 10- to 400-kHz band, the techniques of impulse and side-looking radar in the 50- to 10,000-MHz band, and also some optical techniques using imagery obtained from a satellite. Low frequency case studies demonstrate the use of the techniques for detecting free water under an ice cover in shallow, almost completely frozen lake basins, and thaw zones within lake beds, stream channels, and in permafrost in general. The radar studies demonstrate the use of these techniques for determining depth of free water and ice cover thickness on lakes and rivers
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    Pages: iv, 30 Seiten , Illustrationen
    Series Statement: CRREL Report 79-15
    Language: English
    Note: CONTENTS Abstract Preface Introduction Part I. Low frequency resistivity methods Resistivity of earth materials Theory and description of techniques Surface impedance technique Airborne radiowave technique Magnetic induction technique Case studies Location of thaw zones beneath lakes and rivers Location of permeable materials in unfrozen ground Delineating permafrost boundaries Part II. High frequency dielectric methods Dielectric properties of earth materials Theory and description of equIpment Profiling radar Imaging radar Case studies Radar profile of a river channel Impulse radar profile of a freshwater lake SLAR imagery of Arctic lakes Literature cited Appendix A: Satellite imagery for subsurface water exploration
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  • 49
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-79/22
    In: CRREL Report, 79-22
    Description / Table of Contents: Field observations at 60 Sites located in the fast or near-fast ice along a 1200-km stretch of the north coast of Alaska between Bering Strait and Barter Island have shown that the great majority of the ice samples (95%) exhibit striking c-axis alignments within the horizontal plane. Such alignments were usually well developed by the time the ice was 50 cm thick and in some cases when the ice was 20 cm thick. In all cases the degree of preferred orientation increased with depth in the ice. Representative standard deviations around a mean direction in the horizontal plane are commonly less than ± 10° for samples collected near the bottom of the ice. The general patterns of the alignments support a correlation between the preferred c-axis direction and the current direction at the ice/water interface. A comparison between c-axis alignments and spot current measurements made at 42 locations shows that the most frequent current direction coincides with the mean c-axis direction. Such alignments are believed to be the result of geometric selection with the most favored orientation being that in which the current flows normal to the (0001) plates of ice that compose the dendritic sea ice/sea water interface.
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    Pages: v, 21 Seiten , Illustrationen
    Series Statement: CRREL Report 79-22
    Language: English
    Note: CONTENTS Abstract Preface Summary Introduction Techniques and sampling Observations Crystal alignments “Odd” sites Causes Conclusions Literature cited Appendix A: Current observations
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  • 50
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-79/9
    In: CRREL Report, 79-9
    Description / Table of Contents: Sedimentation at the terminus of the Matanuska Glacier has been found to be primarily subaerial in a 100- to 300-m wide, ice-cored zone paralleling the edge of the active ice. Certain physical and chemical characteristics of the ice and debris of the superglacial, englacial and basal zones of the glacier indicate the debris of the basal zone, the primary source of sediment, is entrained during freeze-on of meltwater, probably surficially derived, to the glacier sole. Till formation results from the melting of buried ice of the basal zone. Melt-out till inherits the texture and particle orientations of basal ice debris; other properties are not as well preserved. Most deposits result from resedimentation of till and debris by sediment gravity flows, meltwater sheet and rill flow, slump, spall, and ice ablation. Depositional processes are interrelated in the process of backwasting of ice-cored slopes. Sediment flows are the primary process of resedimentation. Their physical characteristics, multiple mechanisms of flow and deposition, and characteristics of their deposits vary with the water content of the flow mass. Deposits of each process are distinguished from one another by detailed analysis of their internal organization, geometry and dimensions, and the presence of other internal and related external features. Genetic facies are defined by these characteristics. The interrelationship of processes develops a composite depositional sequence defined in terms of genetic facies associations; an upper, resedimented facies association, a middile, till facies association, and a lower, subglacial-resedimental facies association. The lateral and vertical distribution of genetic facies within the associations is mainly nonrepetitive.
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    Pages: X, 112 Seiten , Illustrationen , 1 Beilage
    Series Statement: CRREL Report 79-9
    Language: English
    Note: CONTENTS Abstract Preface Summary Chapter 1. Introduction Field site Historical background Chapter 2. Characteristics of the debris and ice Characteristics of the facies and subfacies Basal zone Characteristics of the debris Discussion Chapter 3. Oxygen isotope analysis Sampling and analysis Results Discussion Chapter 4. Depositional processes—till formation Methods of analysis Environmental setting Till formation Chapter 5. Depositional processes—resedimentation Sediment flows Other resedimentation processes Resedimentation process relationships Chapter 6. Process distribution, sediment dispersal and depositional patterns Physical characteristics Sediment dispersal Sedimentary facies Patterns of terminus sedimentation Chapter 7. Conclusions Literature cited
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  • 51
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-79/21
    In: CRREL Report, 79-21
    Description / Table of Contents: The report studies the question of whether Great Lakes freighters could move effectively through ice-clogged channels with the aid of tows provided by warping or kedging systems. Ten operational concepts are outlined, and their advantages and disadvantages are noted. The crushing resistance of floating brash ice is then analyzed. The neutral, active and passive states of stress for laterally confined brash ice are considered, and the resistance to horizontal thrusting by a smooth vertical wall is calculated for cohesionless brash ice, and for ice in which there is finite cohesion between the ice fragments. The thickening of the ice cover in the vicinity of a "pusher", and the formation of pressure ridges, are analyzed in order to estimate the amount of pile-up that can occur against a ship hull. The analysis then moves on to consideration of ship resistance by brash ice, taking into account crushing resistance at the bow, tangential friction at the bow, and hull friction aft of the bow section. Comparisons are made between thrust from the ship’s screws and the calculated ice resistance. The next section of the report estimates the force requirements for a warping or kedging system in terms of thrust augmentation for existing vessels. Tow cable requirements are given, and estimates are made for cable anchors and for anchorage of underwater structures. The force and power requirements for winches and windlasses are given, the practical problems involved in the pickup or transfer of cables are mentioned, and the report concludes with a brief appraisal. The conclusion is that a simple warping tug system is appropriate for a full scale experiment, a chain ferry with auxiliary barge seems attractive for an operational system, and a chain ferry plow may be an efficient way to clear ice from channels.
    Type of Medium: Series available for loan
    Pages: iv, 21 Seiten , Illustrationen
    Series Statement: CRREL Report 79-21
    Language: English
    Note: CONTENTS Abstract Preface Introduction Operational concepts A. Warping tug system B. Chain ferry system C. Chain ferry with auxiliary barge D. Ski tow system E. Dual winch warping system F. Simple kedging G. Trailing-line system H. Above-surface dual winch system I. Pulley systems J. Chain ferry plow Crushing resistance of fragmented ice covers Resistance to ship passage by broken ice Crushing resistance at the bow Tangential friction at the bow Hull friction aft of the bow section Total ship resistance from brash ice Comparison of ship thrust and ice resistance Force requirements for a warping or kedging system Tow cable requirements Anchors and anchorages Force and power requirements for winches and windlasses Pickup or transfer of cable General appraisal Literature cited
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  • 52
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-82/12
    In: CRREL Report, 82-12
    Description / Table of Contents: From a high-quality set of velocity, temperature, and humidity profiles collected upwind and downwind of a step change in surface roughness, temperature, and moisture, we have calculated upwind and downwind values of the heat fluxes and friction velocity. The surface change is from smooth to rough; upwind, the sensible heat flux is upward and the latent heat flux is zero; downwind, the surface is well-watered so that the latent heat flux is upward while the sensible heat flux is downward. The downwind latent heat flux in this fetch-limited flow obeys NL=0.08 Rx 0.76 where NL is the latent heat Nusselt number and Rx is the fetch Reynolds number, a parameter for characterizing fetch-limited flows. Because this relation is virtually the same as one found to describe the sensible heat and condensate fluxes over arctic leads, we conclude that the Nusselt numbers nondimensionalizing scalar fluxes are the same for a given fetch Reynolds number when boundary conditions are similar.
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    Pages: vii, 18 Seiten , Illustrationen
    Series Statement: CRREL Report 82-12
    Language: English
    Note: CONTENTS Abstract Preface List of symbols Introduction Upwind: flux gradient method Downwind: integral method ResulIts Energy budget Latent heat flux Surface stress Downwind humidity profiles Discussion Conclusions Literature cited
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  • 53
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    Call number: ZSP-201-82/10
    In: CRREL Report, 82-10
    Description / Table of Contents: Dielectric measurements have been performed on silt and sand samples from permafrost areas using Time Domain Reflectometry. The sample temperatures were varied from +25 °C to -25 °C, and volumetric water content was varied between oven-dry and 0.55 gH2O/cm3. The data were processed for frequencies between 0.1 and 5.0 GHz. The results show a constant K' and a low K' for frequencies up to 1 GHz. A frequency dependence seen on the data above 2 GHz is probably the result of unfrozen, adsorbed water. At moisture levels near saturation at all temperatures, these soils have excellent propagation characteristics for ground-probing radar operating below 0.3 GHz. Massive ice should be easily detectable in permafrost within a few degrees of 0 °C.
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    Pages: 7 Seiten , Illustrationen
    Series Statement: CRREL Report 82-10
    Language: English
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  • 54
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    Call number: ZSP-201-82/9
    In: CRREL Report, 82-9
    Description / Table of Contents: This study deals with the distribution of forces along the converging boundaries of the Port Huron, Michigan, region where unconsolidated ice in Lake Huron is held against wind and water stresses. An experimental basin was built to induce uniform shear stress on the model ice cover by flowing water beneath the ice. The boundary segments, which held the ice cover in the region, were instrumented to measure force in the normal and tangential directions. The distribution of normal forces along the boundary was compared with as distribution derived by using a theoretical model. An ice control structure (ICS) was installed in the basin and experiments were conducted to measure the forces on the ICS and the ice release through the opening in the ICS during simulated ship passages. The experimental results are presented in a nondimensional form. In addition, the force per unit length on the ICS and the area of ice released through its opening were estimated for the expected wind conditions at the Port Huron site.
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    Pages: v, 27 Seiten , Illustrationen
    Series Statement: CRREL Report 82-9
    Language: English
    Note: CONTENTS Abstract Preface List of symbols Introduction Theoretical models Case 1 Case 2 Case 3 Experimental program Experimental facility Scaling factors Experimental results Analysis of wind data for lower Lake Huron Summary and conclusions Release of ice through the opening of an ICS Ice forces on the ice control structure Ice forces on ice control structure from a large unconsolidated ice cover Literature cited Appendix A. Equation for the stress resultants and velocities of the ice cover Appendix B. Monthly summary of wind data at Port Huron
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  • 55
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-82/7
    In: CRREL Report, 82-7
    In: Charged dislocation in ice, II.
    Description / Table of Contents: The contribution of electrically charged dislocation motion to dielectric relaxation was studied theoretically. Experimentally obtained data on charge density, dislocation density, and segment length and distribution described in Part I of this series were used to calculate dielectric relaxation spectra. The results indicate that the charged dislocation process can produce the observed audio frequency dielectric relaxation as well as the distribution of spectra.
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    Pages: iii, 15 Seiten , Illustrationen
    Series Statement: CRREL Report 82-7
    Language: English
    Note: CONTENTS Abstract Preface Introduction Theoretical development of dielectric relaxation due to charged dislocations Numerical calculations for distributed segment length Discussion Conclusions Literature cited Appendix A. Mosotti type catastrophe by charged dislocation processes
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  • 56
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    Call number: ZSP-201-82/8
    In: CRREL Report, 82-8
    Description / Table of Contents: A detailed analysis of methods for calculating the thermal conductivity of soils is presented, and trends in the predic­tions of these methods are compared. The influence of changes in the moisture content on the calculated thermal con­ductivity of a soil (at constant dry density) is shown, as is the sensitivity of this calculated value to changes in dry den­sity or in the soil solids’ thermal conductivity. The methods are evaluated to determine the extent of agreement of their predictions with measured values obtained on soils of known composition and properties. The deviations of the predicted values are determined for soils that are unfrozen or frozen, coarse or fine, unsaturated, saturated or dry. The applicability of each of the methods under various conditions is determined and recommendations are made as to the best method for each condition.
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    Pages: vi, 90 Seiten , Illustrationen
    Series Statement: CRREL Report 82-8
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Analysis of methods for calculating thermal conductivity Introduction Influence of moisture content on thermal conductivity Influence of dry density on thermal conductivity Influence of soil solids’ thermal conductivity Comparison of the various methods Evaluation of methods for calculating thermal conductivity Soils data used for evaluation Computer program Applicability of the methods Discussion and conclusions Applicability to unfrozen soils Applicability to frozen soils Applicability to saturated soils Effect of soil mineral composition Applicability to dry soils Summary of applicability of methods Literature cited Appendix A: Properties of some test soils Appendix B: Comparison of thermal conductivity values computed by the various methods and of their deviations from the values measured
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  • 57
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-79/27
    In: CRREL Report, 79-27
    Description / Table of Contents: Some Bessel function identities found by solving problems of the deflection of a floating ice plate by two different methods are rigorously proved. The master formulas from which all the identities are derived are in a Fourier reciprocal relationship, connecting a Hankel function to an exponential function. Many new formulas can be derived from the master formulas. The analytical method presented here now opens the way to study a hitherto impossible type of problem--the deflection of floating elastic plates of various shapes and boundary conditions.
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    Pages: ii, 13 Seiten , Illustrationen
    Series Statement: CRREL Report 79-27
    Language: English
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  • 58
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    Call number: ZSP-201-79/28
    In: CRREL Report, 79-28
    Description / Table of Contents: Transmission and scanning electron micrographs of Umiat bentonite revealed thin, mica-like grains with irregular shapes. Most of the bentonite showed electron diffraction ring patterns, but some showed hexagonal net patterns as well as ring patterns. The lengths of the unit cells were calculated to be 5.18 A along the a-axis and 8.97 A along the b-axis. Semiquantitative analyses were made using an energy dispersive spectrometer. Common elements such as Si, Ti, Al, Fe, Mg, Na and K were determined. The molecular ratio of SiO2:Al2O3 was calculated to be 492:100 for the bulk sample, indicating that Umiat bentonite is similar in most respects to Wyoming bentonite, and is classified as a mont-morillonite. The microstructure of frozen Umiat bentonite was observed at a specimen temperature of -100 C using a scanning electron microscope equipped with a cold stage. Frozen bentonite and segregated ice patterns formed from wet bentonite were examined using an X-ray map and Si X-ray line scan. Sublimation processes of ice in the frozen bentonite were observed at specimen temperatures of -60 and -80 C. After sublimation of the ice the bentonite displayed a honeycomb structure. It was concluded that the freezing-sublimation cycle in frozen soil increases the permeability of water vapor due to the three-dimensional structure of the coagulated clay formed by freezing.
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    Pages: iii, 14 Seiten , Illustrationen
    Series Statement: CRREL Report 79-28
    Language: English
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  • 59
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    Call number: ZSP-201-79/29
    In: CRREL Report, 79-29
    Description / Table of Contents: An analytical study of the propagation of shock waves in snow was carried out to evaluate the response of medium density snow to high rates of loading. One solution was developed for steady shock waves; this resulted in calculation of pressure jump, density jump and stress wave speed. Correlation with available experimental data was found to be good. Nonsteady shock waves were also considered in order to evaluate wave attenuation rates in snow. Very few data were available to compare with the analytical results, so no definite conclusions on the part of the study could be made. The results show, however, that shock waves that produce plastic deformation attenuate at extremely high rates and that differences in pressure between two waves are quickly eliminated within a short distance. Calculations were also made to evaluate the effect of wave frequency on attenuation rates. The results show that, for plastic waves, frequency is not a predominant factor for determining attenuation rates.
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    Pages: v, 14 Seiten , Illustrationen
    Series Statement: CRREL Report 79-29
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature I. Introduction II. A constitutive law for snow and balance principles III. Compatibility laws and jump equations for stress waves IV. Steady shock waves in snow V. Comparison of steady-wave theory with experimental results VI. A numerical solution to the nonsteady wave problem VII. Jump equations for nonsteady shock waves VIII. Reduced jump equations Discussion and conclusions Literature cited
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  • 60
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    Call number: ZSP-201-79/25
    In: CRREL Report, 79-25
    In: Charged dislocation in ice, I.
    Description / Table of Contents: The motion of dislocations in single crystal ice under an electric field was observed by using X-ray topographic methods. Electric charge density on these dislocations was deduced from the amplitude and length of the dislocation segment under the known AC electrical field. The most likely linear charge density was about +5x10^-11 c/m, although considerable variation is possible depending on the effective field acting on the dislocation lines.
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    Pages: iii, 12 Seiten , Illustrationen
    Series Statement: CRREL Report 79-25
    Language: English
    Note: CONTENTS Abstract Preface Introduction Theory Experimental apparatus and procedure Results Discussion Concluding remarks Selected bibliography Appendix A. Mosotti type field on core of cylindrical cavity
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  • 61
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    Call number: ZSP-201-79/26
    In: CRREL Report, 79-26
    Description / Table of Contents: A 19-year record of the annual closing and opening dates of operation of the Lake Champlain ferry at Grand Isle, Vermont, which are controlled by the lake's ice cover, was made available to CRREL. These navigation records accurately approximated the freeze-over and breakup dates for the ferry crossing area between Gordon Landing, Vermont, and Cumberland Head, New York. When compared statistically with water temperature and climatological data for the same years at nearby Lake Champlain locations, the dates allowed accurate predictions of ice formation. From nearby air temperature records, cumulative freezing degree-day (deg C) curves were plotted for each year of record, and ice formation dates and standard deviations were predicted with considerable accuracy. Several methods of predicting ice formation on Lake Champlain were attempted. The most accurate approach used a combination of water temperatures and freezing degree-days. The influence of wind speed on ice cover formation and prediction are also discussed in the report.
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    Pages: v, 21 Seiten , Illustrationen
    Series Statement: CRREL Report 79-26
    Language: English
    Note: CONTENTS Abstract Preface Introduction Data tabulation and collection Air temperatures 11-reezing degree-days Water temperatures Closing and opening dates Results Air temperature Freezing degree-days Water temperatures Analysis: Attempted methods of predicting ice formation Predicting air temperatures 8Summer water temperatures Fall water temperatures and freezing degree-days Wind speed influence on closing of the lake Water temperature vs surface air temperature analysis Prediction of ice-out dates Conclusions Literature cited Appendix A. Freezing degree-day curves with ice notations and watertemperature notations Appendix B. Summary
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  • 62
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    Call number: ZSP-201-79/24
    In: CRREL Report, 79-24
    Description / Table of Contents: By using a new thermocoring technique, a hole was successfully drilled through the 416-m thickness of the Ross Ice Shelf at J-9 Camp. This report provides a description of the drill and an account of this drilling project. A provisional examination of the core shows the ice shelf to consist of 410 m of snow and glacial ice underlain by 6 m of sea ice formed by direct freezing of sea water to the bottom of the Ross Ice Shelf.
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    Pages: ii, 12 Seiten , Illustrationen
    Series Statement: CRREL Report 79-24
    Language: English
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  • 63
    Call number: ZSP-201-79/23
    In: CRREL Report, 79-23
    Description / Table of Contents: The performance of surface impedance and magnetic induction electromagnetic subsurface exploration techniques was studied seasonally at various sites in Alaska where permafrost and massive ground ice occurred. The surface impedance method, which uses radiowaves in the LF and VLF bands, and the magnetic induction method, which uses low-frequency magnetic induction fields, distinguish subsurface materials by the electrical resistivity of the materials. The methods used have greatest sensitivity within about 20 m of the surface and are, therefore, most applicable for shallow subsurface investigations. The selection of study sites was based on anticipated contrasts in electrical resistivity between ground ice and adjacent earth materials. A magnetic induction instrument, using a separation of 3.66-m between the transmitter and receiver antennas, in general was able to detect near-surface zones of massive ice and to provide data regarding permafrost distribution in both the Fairbanks and Prudhoe Bay areas. At this antenna separation, the depth of magnetic field penetration was sufficient to include mainly the zone containing maximum contrasts in resistivity between ground ice and other earth materials. In the Fairbanks area, contrasts, in this zone were greatest in late winter when the seasonally thawed surface layer was completely frozen. When thawed, this layer usually becomes more conductive and often masks the deeper resistivity contrasts. In the Prudhoe Bay area, maximum ground resistivity contrasts were detected in late summer when shallow subsurface temperatures had risen sufficiently to permit resistivity contrasts between the massive ice and the ice-rich ground to appear.
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    Pages: v, 24 Seiten , Illustrationen
    Series Statement: CRREL Report 79-23
    Language: English
    Note: CONTENTS Abstract Preface Introduction Background Obiectives and procedures Ground electrical resistivity in permafrost regions Electromagnetic techniques General Magnetic induction method Surface impedance fradiowave method Direct current method General description of field sites Results Site 1 CRREL permafrost station, Fairbanks, Alaska Site 2 Planned road cut for Steese Highway near Fox, Alaska Site 3 Relic floodplain near Fairbanks, Alaska Site 4 Pingos, Prudhoe Bay, Alaska Site 5 Ice wedges, Prudhoe Bay, Alaska Comparisons between the surface impedance and magnetic induction methods Conclusions and recommendations Literature cited Appendix A. Discussion of the depth of sensitivity of the magnetic induction method using two- and three-layer apparent resistivity curves
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  • 64
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    Call number: ZSP-201-83/31
    In: CRREL Report, 83-31
    Description / Table of Contents: A mathematical model is described that is used to determine the maximum ice conveyance capacity of a river channel. Based upon this model, computer programs were developed that enable the ice discharge to be calculated for steady-state flow conditions. For rivers that have uniform flow, the maximum ice-conveying capacity can be described with a simple function expressed in terms of the size of the ice fragments, channel geometry, and the flow of water in the river. For nonuniform flows, the computer program determines the elevation profile of the surface layer in addition to other flow characteristics, such as the velocity and surface concentration of the ice fragments. The location along this surface profile where the ice conveyance capacity becomes less than the upstream supply is determined and is considered to be the position where a surface ice jam or ice bridge will be formed.
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    Pages: iv, 21 Seiten , Illustrationen
    Series Statement: CRREL Report 83-31
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Constitutive relationships Equations of motion Uniform flow Nonuniform flow Ice transport: Uniform flow Symmetric channel Asymmetric channel Ice transport: Nonuniform flow Further considerations Basis for model improvement Conclusions Literature cited
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  • 65
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    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.
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    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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  • 66
    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.
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    Pages: ii, 8 Seiten , Illustrationen
    Series Statement: CRREL Report 83-32
    Language: English
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  • 67
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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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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  • 68
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    Call number: ZSP-201-83/33
    In: CRREL Report, 83-33
    Description / Table of Contents: A thermodynamic model has been developed that for the first time describes the entire creep process, including primary, secondary, and tertiary creep, and failure for both constant stress (CSR) tests (σ= const.) and constant strain rate (CSR) tests (ϵ = const.), in the form of a unified constitutive equation and unified failure criteria. Deformation and failure areconsidered as a single thermoactivated process in which the dominant role belongs to the change of entropy. Failure occurs when the entropy change is zero. At that moment the strain rates in CS tests reach the minima and stress in CSR tests reaches the maximum (peak) values. Families of creep (ϵ vs τ) and stress-strain (σ vs ϵ) curves, obtained from uni-axial compression CS and CSR tests of frozen soil, respectively (both presented in dimensionless coordinates), are plotted as straight lines and are superposed, confirming the unity of the deformation and failure process and the validity of the model. A method is developed for determining the parameters of the model, so that creep deformation and the stress-strain relationship of ductile materials such as soils can be predicted based upon information obtained from either type of test.
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    Pages: v, 25 Seiten , Illustrationen
    Series Statement: CRREL Report 83-33
    Language: English
    Note: CONTENTS Abstract Nomenclature Introduction Principal relationships Constitutive equation Failure criteria Secondary creep: Flow equations Creep at constant stress (σ = Const.) Creep model Creep strain (σ = Const.) Creep at constant strain rate (ϵ = Const.) Stress-strain relationship Stress/strain/strain rate at failure Test data Preliminary analysis Constant stress tests (σ = Const.) Constant strain rate tests (ϵ = Const.) The principle of superposition Thermodynamic equation of creep Conclusions Literature cited
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  • 69
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    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
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    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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  • 70
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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.
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    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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  • 71
    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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  • 72
    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
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    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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  • 73
    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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  • 74
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-87/13
    In: CRREL Report, 87-13
    Description / Table of Contents: Thermodynamic properties of electrolyte solutions change rapidly below 25C, but these properties are seldom measured over the low temperature range (below 0C), even though some salt solutions can remain unfrozen to -50C. The heat capacities of concentrated solutions (0.5-0.6 molal) of NaC-H2O were measured from 25C to -40C as part of a study to provide thermodynamic data of salt solutions for use in cold regions chemical and geophysical studies. A differential scanning calorimeter was used to measure specific heat capacity from cooling scans as a function of temperature and concentration. The heat capacity data were fit to the equations of Pitzer and coworkers to obtain activity and osmotic coefficients of NaC and H2O, respectively, below o C. Supercooling of the solutions was encouraged by using a fast scan rate (10d2/minute) so that specific heat could be measured to lower temperatures than would be possible if the solutions were allowed to equilibrate with the solid phases. The solubility of ice was calculated and compared to the experiment freezing point of NaC solutions.
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    Pages: ii, 16 Seiten , Illustrationen
    Series Statement: CRREL Report 87-13
    Language: English
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  • 75
    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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  • 76
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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.
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    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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  • 77
    Call number: ZSP-201-85/16
    In: CRREL Report, 85-16
    Description / Table of Contents: This report presents the results of the second 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 2, 62 constant-strain-rate uniaxial compression tests were performed on horizontal and vertical ice samples from multi-year pressure ridges to examine the effect of sample orientation on ice strength. Also conducted were 36 constant-strain-rate tension tests, 55 conventional triaxial tests and 35 constant-load compression tests on multi-year pressure ridge samples to provide data for developing ice yield criteria and constitutive laws. Data are presented on the strength, failure strain and modulus of multi-year sea ice under different loading conditions. The effects of ice temperature, porosity, structure, strain rate, confining pressure and sample orientation on the mechanical properties of multi-year sea ice are examined.
    Type of Medium: Series available for loan
    Pages: vi, 89 Seiten , Illustrationen
    Series Statement: CRREL Report 85-16
    Language: English
    Note: CONTENTS Abstract Preface Introduction Field sampling program Site selection and description Coring procedures Core logging procedures Shipping and storage of ice samples Ice description Salinity and density Structure Constant-strain-rate compression tests Test variables Uniaxial compressive strength Strength and structure Strength and porosity Residual compressive strength Failure strain Initial tangent modulus Constant-strain-rate uniaxial tension tests Test variables Uniaxial tensile strength Failure strains Initial tangent modulus Constant-strain-rate triaxial tests Equipment Test variables Synthane end caps Triaxial strength Failure strains Initial tangent modulus Effect of sinthane end caps on results Constant-load compression tests Test variables Test results Conclusions Literature cited Appendix A: Ice structure profile of ridge C core Appendix H: Test data Appendix C: Static determination of Young's modulus in sea ice
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  • 78
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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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  • 79
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    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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  • 80
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-85/19
    In: CRREL Report, 85-19
    Description / Table of Contents: Ground-probing radar can be an effective tool for exploring the top 10 to 20 m of ground, especially in cold regions where the freezing of water decreases signal absorption. However, the large electrical variability of the surface, combined with the short wavelengths used, can often cause severe ground clutter that can mask a desired, deeper return. In this study a model facility was constructed consisting of a metallic reflector covered by sand. Troughs of saturated sand were emplaced at the surface to vary surface electrical properties and to act as a noise source to interfere with the bottom reflections. Antenna polarization and height, and signal stacking in both static (antennas stationary) and dynamic (antennas moving) modes were then investigated as methods for reducing the surface clutter. Polarization parallel to the profile direction (perpendicular to the troughs' axes) gave profiles superior to the perpendicular case because of the directional sensitivity of the antenna radiation. Dynamic stacking greatly improved the signal-to-noise ratio because noise sources were averaged as the antennas moved, while the desired reflector, buried at constant depth, was enhanced. Raising the antennas above the surface also reduced noise because the surface area over which reflections were integrated increased. All three noise reduction techniques could be effective in surveys for reflectors at nearly constant depth such as groundwater tables or ice/water interfaces if the lateral variation in undesired ground propertiesis sufficiently random.
    Type of Medium: Series available for loan
    Pages: iv, 23 Seiten , Illustrationen
    Series Statement: CRREL Report 85-19
    Language: English
    Note: CONTENTS Abstract Preface Introduction Objective and procedures Materials and methods Subsurface radar Model facility Results Isolated disturbances-surface and raised analog profiles Multiple disturbances Discussion and conclusions Literature cited
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  • 81
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-91/12
    In: CRREL Report, 91-12
    Description / Table of Contents: Field trials using a man-portable Geonics, Ltd., EM31 electromagnetic induction sounding instrument, with a plug-in data processing module, for the remote measurement of sea ice thickness, are discussed. The processing module was made by Flow Research Inc., to directly measure sea ice thickness and show the result in a numerical display. The EM31-processing module system was capable of estimating ice thickness within 10% of the true value for ice from about 0.7 to 3.5 m thick, the oldest undeformed ice in the study area. However, since seawater under the Arctic pack ice has a relatively uniform conductivity (2.5 + or - 0.05 S/m), a simplified method, which can be used for estimating sea ice thickness using jet an EM31 instrument, is discussed. It uses only the EM31's conductivity measurement, is easy to put into use and does not rely on theoretically derived look-up tables or phasor diagrams, which may not be accurate for the conditions of the area.
    Type of Medium: Series available for loan
    Pages: iv, 23 Seiten , Illustrationen
    Series Statement: CRREL Report 91-12
    Language: English
    Note: CONTENTS Preface Introduction EM 31 Sounding concepts Previous EMI studies Beaufort Sea field trials EM 31 Conductivity reading versus sea ice thickness General comments Literature cited Abstract
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  • 82
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-89/25
    In: CRREL Report, 89-25
    Description / Table of Contents: This study provides a detailed chemical and structural profile of first-year and multiyear Arctic sea ice. Ice cores were collected during April- May 1986 and 1987 near Prudhoe Bay, Alaska. Concentrations of Cl, Br, SO4, Na, Ca, K, Mg, PO4, SiO4, NO3, NO2 and NH4 were determined for samples chosen on the basis of structural ice type. Chemical and statistical analyses indicate that finer-grained structures incorporate more impurities and that major ion chemistry is controlled almost entirely by salinity. Mg is enriched in the ice indicating precipitation is occurring at temperatures higher than previously reported. K is depleted in the ice suggesting preferrential drainage. Ratios of the major ions are the same for first-year and multiyear ice and are similar to that of seawater indicating that as the ice ages no significant changes occur in ice chemistry. Nutrient concentrations in the ice are enriched with respect to the underlying water, indicating that biological activity occurs in the ice and processes other than the overall salinity effect and brine drainage are affecting nutrient concentrations within the ice.
    Type of Medium: Series available for loan
    Pages: vi, 144 Seiten , Illustrationen
    Series Statement: CRREL Report 89-25
    Language: English
    Note: CONTENTS Abstract Preface Introduction Background Formation, growth, and structure of sea ice Oceanic frazil production Multiyear ice Equilibrium growth Summer ice decay Annual layering Salinity distribution in sea ice Chemistry of sea ice Study area description Objectives Methodology Sample collection Blanks Chemical analyses Thin sections Data reduction Results and discussion First-year ice Multiyear ice Comparison of first-year and multiyear ice Summary Conclusions Future work References Appendix A: Concentration of chemical species in sea ice as reported in the literature Appendix B: Ice and water data Appendix C: Linear regression data
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  • 83
    Call number: ZSP-201-90/9
    In: CRREL Report, 90-9
    Description / Table of Contents: In 1986, a mobility model was developed for predicting the traction and motion resistance of both wheeled and tracked vehicles on shallow snow, and a winter field season was dedicated to gathering mobility data for a diverse family of vehicles (including four on wheels and three tracked) to validate the model. The original version of the model, SSM 1.0, used the Mohr-Coulomb shear failure equation from soil mechanics to predict gross traction. This required input of the snow strength parameters c and ȹ. Motion resistance is predicted by calculating the amount of work done by the tire in compacting snow and only requires snow depth and density values as input snow properties. Some effort was expended in determining an easy and reliable method of obtaining snow strength established from past instrumented vehicle test results. Historically, shear annulus apparati have been used to obtain Mohr-Coulomb strength parameters. A comparison of snow strength obtained via these three methods (shear annulus, instrumented vehicle, calculated from initial density using the relationship in SSM 1.0) for individual snow covers showed no agreement. SSM 1.0 assumed that snow strength parameters for mobility prediction were a function of initial snow density; however, traction is developed in the compacted snow under the driving element, whose strength properties bore little relation to those of the initial snow. It appears that the shear strength of the compacted snow is essentially a constant for all of the vehicles and snow covers tested here. Based on this finding, a new traction algorithm was developed, resulting in the creation of a second generation model, SSM 2.0. This algorithm predicts gross traction, on the average for the vehicles tested, within 7% of the measured value. Motion resistance prediction remains unchanged in SSM 2.0. This quantity is still not predicted with a desirable level of accuracy.
    Type of Medium: Series available for loan
    Pages: v, 72 Seiten , Illustrationen
    Series Statement: CRREL Report 90-9
    Language: English
    Note: CONTENTS Preface Nomenclature Introduction Background Field experiments Test location and test sites Test vehicles Test procedures Results CIV traction and motion resistance Wheels/trackcs vehicles traction and motion resistance Shear annulus device Accuracy and limitations of data Snow conditons Analysis Determination of snow strength parameters Traction analysis Traction model predictions Resistance analysis Resistance model predictions Conclusions and recommendations Literature cited Appendix A: Shallow snow mobility model, version 1.0 Appendix B: Test vehicle data Appendix C : Selected test data Appendix D : Snow data Appendix E: Shallow snow mobility model code, version 2.0 Abstract
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  • 84
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-91/5
    In: CRREL Report, 91-5
    Description / Table of Contents: An analysis of the National Science Foundation's surface vehicle fleet in Antarctica is reported on here. Surface vehicle needs have been determined through interviews of vehicle users, managers and maintainers, and from direct on-site observation. An ideal grouping of vehicle categories is proposed that will address current needs and provide flexibility for the future. Ultimately, recommendations for streamlining and modernizing the NSF Antarctic vehicle fleet are made. Cargo transportation over snow was identified as being in a crisis state. Personnel movement functions for all but traversing are performed adequately at this time, although there is much room for improvement. Brands and models must be selected for some categories of recommended vehicle types. This will naturally follow a more in-depth analysis of candidates and discussions with NSF vehicle managers. A purchasing plan, including a time table, budget, and desired sequence of replacement, must then be formulated and executed.
    Type of Medium: Series available for loan
    Pages: v, 71 Seiten , Illustrationen
    Series Statement: CRREL Report 91-5
    Language: English
    Note: CONTENTS Preface Executive summary Introduction Regional divisions Zone A - rock and ice roads Zone B - local ice Zone C - traverse Zone D - ice edge Zone E - remote field site Zone F - inland station Current transportation needs in Antarctica Future transportation needs Transportation analysis Personnel transport Cargo transport Summary of analysis Recommendations for changes to U.S. vehicle fleet Conclusions and summary of findings Literature cited Appendix A: Age distribution of NSF surface vehicles Abstract
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  • 85
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-76/26
    In: CRREL Report, 76-26
    Description / Table of Contents: Debris over a 44-mile stretch of the Chena River was studied. The study area extended from the first bridge on the Chena Hot Springs Road to the Chena River Flood Control damsite. The purpose of the study was to assess the potential danger to the Chena River Flood Control Dam outlet structure. Debris was catalogued, log jams were measured, and sources of debris were studied. The average size of logs was determined, as well as the number of logs present on the river. The authors concluded that a serious debris problem existed and would remain serious for the foreseeable future. Recommendations for debris handling were made.
    Type of Medium: Series available for loan
    Pages: iv, 17 Seiten , Illustrationen
    Series Statement: CRREL Report 76-26
    Language: English
    Note: Contents Abstract Preface Summary Introduction Origin of debris Volume, magnitude Types of debris Hazards of the debris Recommended measures to counteract log jamming Conclusions and recommendations Future work Epilogue Selected bibliography Appendix: Additional photographs of Chena River debris
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  • 86
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-76/25
    In: CRREL Report, 76-25
    Description / Table of Contents: The primary objective of this investigation was to compile baseline information pertaining to the ocean circulation, especially the extent and patterns of tidal currents and tidal flushing, in Cook Inlet, Alaska, utilizing aircraft and satellite imagery with corroborative ground truth data. LANDSAT-1 and NOAA-2 and -3 imagery provided repetitive, synoptic views of surface currents, water mass migration and sediment distribution during different seasons and tides. Color, color infrared and thermal infrared imagery acquired on 22 July 1972 with the NASA NP-3A aircraft were used to analyze currents, mixing patterns and sediment dispersion in selected areas. Temperature(C), salinity (0/00) and suspended sediment concentration (mg/l) data and hand-held photography were utilized as ground truth information in the interpretation of the aircraft and satellite imagery. Coriolis effect, semidiurnal tides and the Alaska current govern the estuary circulation. Clear, oceanic water enters the inlet on the southeast during flood tide, progresses northward along the east shore with minor lateral mixing, and remains a distinct water mass to the latitude of Kasilof-Ninilchik. South of the forelands, mixing with turbid inlet water becomes extensive. Turbid water moves south primarily along the north shore during ebb tide and a shear zone between the two water masses forms in mid-inlet south of Kalgin Island. Currents adjacent to and north of the forelands are complicated by tidal action, coastal configuration and bottom effects. Turbulence is greatest throughout the water column along the south shore and stratification is more pronounced in Kamishak and Kachemak Bays, especially when fresh water runoff is high.
    Type of Medium: Series available for loan
    Pages: ix, 92 Seiten , Illustrationen
    Series Statement: CRREL Report 76-25
    Language: English
    Note: CONTENTS Abstract Preface Summary Conversion factors: U.S. customary to metric (SI) units of measurement. Introduction Background Objectives Project history Approach Aircraft imagery LANDSAT-1 imagery NOAA-2 and -3 satellite imagery Ground truth data Imagery and ground truth data analysis Physical and cultural setting Geography Geology Climate Hydrology Local industry and population density Sources of estuarine pollution Results and discussion Coastal configuration Bathymetry Tides Asymmetry of tidal flow/duration across inlet Suspended sediment distribution and circulation Sea ice Tidal flushing characteristics Summary and conclusions Applications Recommendations Literature cited Appendix A. RS-14 infrared scanner imagery
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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-201-76/27
    In: CRREL Report, 76-27
    Description / Table of Contents: In Part I a physically based model was used to predict daily snowmelt on 2000 m sq plots in the Subarctic. The plots had a range of aspects and inclinations in boreal forest and on the tundra. The energy balance, computed for each of the plots, was compensated for differences in radiative and turbulent energy fluxes caused by varied slope geometry and vegetative cover. The turbulent energy fluxes were also corrected for the effects of the stable stratification of the air over the snow surface. The predictions of the model were compared with daily melts derived from runoff measured on the snowmelt plots. The results show that the method is a good predictor of daily amounts of snowmelt, although some uncertainties are introduced by changes in the snow surface during the melt period. In Part II, a physically based model of the movement of water through snowpacks was used to calculate hydrographs generated by diurnal waves of snowmelt on the tundra and in the boreal forest of subarctic Labrador. The model was tested against measured hydrographs from hillside plots that sampled a range of aspect, gradient, length, vegetative cover, and snow depth and density. The model yielded good results, particularly in the prediction of peak runoff rates, though there was a slight overestimate of the lag time. A comparison of predictions against field measurements indicated that, given the ranges over which each of the controls is likely to vary, the two most critical factors controlling the hydrograph are the snow depth and the melt rate, which must be predicted precisely for short intervals of time. Permeability of the snowpack is another important control, but it can be estimated closely from published values.
    Type of Medium: Series available for loan
    Pages: ix, 40 Seiten , Illustrationen
    Series Statement: CRREL Report 76-27
    Language: English
    Note: Contents: Abstract Preface Summary Notation Scope of the study Part I. Energy balance computations Introduction The experimental sites Instrumentation Theoretical Radiation heat flow Hr Sensible heat flux Hc and latent heat flux He The application of the heat flow model Results and discussion Conclusions and recommendations Part II. Comparison of water runoff computations and measurements Introduction The runoff model The unsaturated zone The saturated layer The field study Instrumentation of the plots Descriptive hydrology Application of the runoff model The unsaturated zone The saturated zone Discussion and conclusions Comparison of predicted and observed hydrographs Factors affecting results Literature cited
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  • 88
    Call number: ZSP-201-76/35
    In: CRREL Report, 76-35
    Description / Table of Contents: Crystalline textures and fabrics of ice cores from the 2164-m-thick ice sheet at Byrd Station, Antarctica, reveal the existence of an anisotropic ice sheet. A gradual but persistent increase in the c-axis preferred orientation of the ice crystals was observed between the surface and 1200m. This progressive growth of an oriented crystal fabric is accompanied by a 20-fold increase in crystal sized between 56 and 600m, followed by virtually no change in crystal size between 6000 and 1200m. A broad vertical clustering of c-axes develops by 1200m. Between 1200 and 1300 m the structure transforms into a fine-grained mosaic of crystals with their basal glide planes now oriented substantially within the horizontal. This highly oriented fine-grained structure, which persists to 1800m, is compatible only with a strong horizontal shear deformation in this part of the ice sheet. Rapid transformation from single- to multiple-maximum fabrics occurs below 1800m. This transformation, accompanied by the growth of very large crystals, is attributed to the overriding effect of relatively high temperatures in the bottom layers of old ice at Byrd Station rather than to a significant decrease in stress. The zone of single-maximum fabrics between 1200 and 1800 m also contains numerous layers of volcanic dust. Fabrics of the very fine-grained ice associated with these dust bands indicate the bands are actively associated with shearing in the ice sheet. Some slipping of ice along the bedrock seems likely at Byrd Station, since the basal ice is at the pressure melting point and liquid water is known to exist at the ice/rock interface.
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    Pages: v, 30 Seiten , Illustrationen
    Series Statement: CRREL Report 76-35
    Language: English
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  • 89
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-95/7
    In: CRREL Report, 95-7
    Description / Table of Contents: Before vehicle mobility in snow can be reliably predicted, a complete understanding of motion resistance in snow is required. This report examines several aspects of wheeled vehicle motion resistance using results obtained with the CRREL instrumented vehicle. Resistances of leading and trailing tires are examined. Limited data are presented for undercarriage drag, and third and fourth wheel passes in the same rut are initially analyzed, as is how snow deforms around a wheel. For the CRREL instrumented vehicle, a trailing tire has a resistance coefficient of about 0.017 for snow depths less than about 22cm. For deeper snow, the disruption of the snowpack caused by a preceding wheel causes snow to fall into the rut, resulting in higher trailing tire coefficients. For larger vehicles, which in some cases have trailing tires carrying larger loads than preceding tires, the trailing tire coefficients are on the order of 0.048 and 0.025 for second and third trailing wheels respectively. Since there are no trailing tire data available for these larger vehicles, these values are based on nonlinear regression analysis, which includes a prediction of the leading tire resistance. The results and observations of this study are applied in a reanalysis of the towed resistance data obtained during the U.S. Army's Wheels vs. Tracks study. An improved algorithm is presented for predicting wheeled vehicle motion resistance caused by snow.
    Type of Medium: Series available for loan
    Pages: v, 39 Seiten , Illustrationen
    Series Statement: CRREL Report 95-7
    Language: English
    Note: CONTENTS Page Preface Nomenclature Introduction Experimental procedure Results and analysis Leading tire resistance Trailing tire resistance Deep snow Undercarriage drag Multiple passes Shallow snow resistance model Summary Literature cited Appendix A: Snow data Appendix B: Observations of snow deformation by a wheel Appendix C: Wheeled vehicle motion resistance data Abstract
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  • 90
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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-201-95/11
    In: CRREL Report, 95-11
    Description / Table of Contents: A pavement joint seal prevents the passage of liquids into the pavement base and the intrusion of solids into the joint. The primary mechanical requirements of a pavement seal are that it respond elastically or viscoelastically to any movement of the joint without failure and that it withstand indentation of hard objects like rocks. Because pavement joint movements and seal deformations can be large, elastomeric sealants are often used to form seals. Winter conditions are recognized as the most critical for a seal because of the possibility that failure stresses will be reached as the joint opens to a maximum and the material stiffens in response to the temperature reduction. This report reviews the specific problems and requirements that cold climates create for the performance of elastomeric seals. Emphasis is placed on the material response behavior that can lead to failure of a seal. In an attempt to clarity the mechanics of sealant and seal performance associated with low-temperature pavement applications and to address the issue of low-temperature stiffening That should be a dominant factor in the selection of a sealant, this report presents background information on the formulation and mechanical properties of elastomeric seal materials and the structural behavior of field-molded joint and crack seals.
    Type of Medium: Series available for loan
    Pages: iv, 20 Seiten , Illustrationen
    Series Statement: CRREL Report 95-11
    Language: English
    Note: CONTENTS Page Preface Introduction Elastomers and sealant formulations Mechanical behavior of sealants Phenomenological behavior of rubbers and elastomers Hyperelastic constitutive model Examples of sealant behavior Mechanical response of seals Basic structural geometry and loading configurations of seals Conventional performance testing for studying the load and deformation response of joint and crack seals Response of seals to joint movements Summary and recommendations Literature cited Abstract
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  • 91
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-76/46
    In: CRREL Report, 76-46
    Description / Table of Contents: The topological properties of 10 stream networks having moderate to well developed trellis drainage patterns have been compared with those expected in a topologically random population. Magnitude 4 subnetworks show a systematic departure from expectation which can be related to geological controls. A link type classification system was developed and a series of equations describing the probability of occurrence of link types in topologically random populations derived. Analysis of the link structure in the channel networks showed small but persistent deviations from expectation in the well developed trellis pattern streams. The general conclusion is that the topologically random model is a very useful standard with which to compare real channel networks.
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    Pages: vi, 54 Seiten , Illustrationen
    Series Statement: CRREL Report 76-46
    Language: English
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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-201-77/1
    In: CRREL Report, 77-1
    Description / Table of Contents: Studies of the growth history and structural characteristics of winter ice covers on two New Hampshire lakes are described. These investigations included measurements of ice cover thickness, characterization of the stratigraphic and crystalline structure of the ice, identification and classification of major ice types and measurements of electrolytic conductivity. The formation of cracks and flaws in the ice and their effects on the mechanical properties of the ice were also investigated. A method of correlating ice growth with surface wind and temperature measurement is described and the interrelationships of the various physical and mechanical properties of temperate lake ice covers are discussed.
    Type of Medium: Series available for loan
    Pages: v, 29 Seiten , Illustrationen
    Series Statement: CRREL Report 77-1
    Language: English
    Note: CONTENTS Abstract Preface Summary Introduction Study areas Study methods Winter freeze-up Composition of ice cover Freezing degree day records and applications Evaluation of ice growth coefficient α Growth history and entrapped bubble stratigraphy Mechanical properties Electrolytic conductivity Literature cited
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  • 93
    Call number: ZSP-201-76/33
    In: CRREL Report, 76-33
    In: Detecting structural heat losses with mobile infrared thermography / R.H. Munis, S.J. Marshall and M.A. Bush, Part IV
    Description / Table of Contents: During the winter of 1973-74 a mobile infrared thermography system was used to survey campus buildings at Dartmouth College, Hanover, New Hampshire. Both qualitative and quantitative data are presented regarding heat flow through a small area of a wall of one brick dormitory building before and after installation of aluminum reflectors between radiators and the wall. These data were used to estimate annual cost savings for 22 buildings of similar construction having aluminum reflectors installed behind 1100 radiators. The data were then compared with the actual savings which were calculated from condensate meter data. The discrepancy between estimated and actual annual cost savings is explained in detail along with all assumptions required for these calculations.
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    Pages: iii, 14 Seiten , Illustrationen
    Series Statement: CRREL Report 76-33
    Language: English
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  • 94
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-76/34
    In: CRREL Report, 76-34
    Description / Table of Contents: Some physical characteristics of two grounded floebergs (fragments of multi-year pressure ridges) near Prudhoe Bay, Alaska, are described. Cross-sectional profiles of the sails and keels of both floebergs were obtained. A sail to keel ratio of 1 to 3.38 obtained with one floeberg was found to be in good agreement with previous investigations. A survey of the sea floor for evidence of scoring induced during grounding yielded a maximum depth of gouging of 1.1m. Additional studies included investigations of the internal structure of the floebergs, and a brief examination of the organic and sedimentary debris found entrained within the floebergs. The grounding of ice on the continental shelves of the Arctic is of considerable interest to those concerned with the development and impact of development of these continental shelves. The field study reported here provides information useful in assessing the nature and characteristics of interactions between floebergs and the sea bed on which they are grounded.
    Type of Medium: Series available for loan
    Pages: iii, 13 Seiten , Illustrationen
    Series Statement: CRREL Report 76-34
    Language: English
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  • 95
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    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-95/14
    In: CRREL Report, 95-14
    Description / Table of Contents: Current protocols for decontaminating devices used to sample groundwater for organic contaminants are re­viewed. Most of the methods given by regulatory agencies provide little scientific evidence that justify the recommended protocols. In addition, only a few studies that actually compared various decontamination proto­cols could be found in the open literature, and those studies were limited in their scope. Various approaches for decontamination and criteria that are important in determining how effectively a surface could be decontami­nated are discussed.
    Type of Medium: Series available for loan
    Pages: iii, 15 Seiten , Illustrationen
    Series Statement: CRREL Report 95-14
    Language: English
    Note: CONTENTS Preface Introduction Sorption and desorption of organic contaminants Decontamination methods Aqueous cleaning methods Cleaning or rinsing with organic solvents Chemical neutralization methods Current protocols to decontaminate groundwater sampling devices Variations in methodology Special instructions for cleaning pumps Effectiveness of various decontamination methods Low-temperature considerations Conclusions Literature cited
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  • 96
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    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-76/36
    In: CRREL Report, 76-36
    Description / Table of Contents: In the past decade, various workers have investigated the use of high-frequency electromagnetic radiation for breaking and excavating rock and frozen ground. This report reviews the high-frequency dielectric properties of these materials, the physics of heating, and the existing literature on these subjects. The high-frequency dielectric properties of rocks and soils, and the absorption of energy by these materials, are mainly determined by their liquid water contents. Computer modeling was used to calculate absorption energy as a function of distance behind irradiated faces of earth materials. The resulting computations showed that most energy is absorbed in the first few centimeters of frozen ground and weak soils. However, in hard rocks of low water content, electromagnetic waves penetrate more deeply, and significant amounts of energy are also absorbed tens of centimeters behind the irradiated faces. Test results showed that electromagnetic rock breakage is feasible only for excavations in hard rock; test results from the use of electromagnetic radiation for excavating tunnels in weak rocks and frozen ground are not promising.
    Type of Medium: Series available for loan
    Pages: iii, 23 Seiten , Illustrationen
    Series Statement: CRREL Report 76-36
    Language: English
    Note: CONTENTS Preface Introduction Sorption and desorption of organic contaminants Decontamination methods Aqueous cleaning methods Cleaning or rinsing with organic solvents Chemical neutralization methods Current protocols to decontaminate groundwater sampling devices Variations in methodology Special instructions for cleaning pumps Effectiveness of various decontamination methods Low-temperature considerations Conclusions Literature cited
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  • 97
    Call number: ZSP-201-76/37
    In: CRREL Report, 76-37
    Description / Table of Contents: Geophysical studies were conducted during September and October of 1975 in northern Maine to locate rock types suitable for construction purposes for the proposed Dickey-Lincoln School Dam Project. Simultaneous airborne magnetometer and VLF electrical resistivity surveys were performed over an area of approximately 920 km2 surrounding the confluence of the St. John and Allagash rivers. The resulting data were used to construct contour maps of apparent resistivity and of total magnetic intensity above the earth's background magnetic field. During the same time period, ground and multi-elevation surveys were performed over a special test sector of known geology. The ground and airborne study in the test sector aided in interpretation of the data by revealing a strong correlation between igneous geology, resistivity, and magnetic intensity. Lack of a similar correlation between resistivity and magnetic data in the remainder of the survey area suggested an absence of additional areas of igneous rocks. The multi-elevation survey of the test area indicated that changes in flight altitude, necessitated by the topographic relief encountered, would not seriously affect the regional resistivity patterns. Although there was no strong evidence of igneous rocks outside the test sector, suitable rock types may exist within the Dss geologic unit (cyclically bedded gray slate and sandstone) in the central part of the main survey area, where most of the high resistivity contours occur.
    Type of Medium: Series available for loan
    Pages: v, 24 Seiten , Illustrationen
    Series Statement: CRREL Report 76-37
    Language: English
    Note: CONTENTS Abstract Preface Summary Introduction Measurement techniques employed Ground Airborne Magnetometer survey Results Ground control study VLF survey Bedrock geology and resistivity Aeromagnetic survey results Conclusions Literature cited Appendix A. Theory of electromagnetic resistivity surveying Appendix B. Magnetic surveying
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  • 98
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-76/40
    In: CRREL Report, 76-40
    Description / Table of Contents: Several original methods were developed to photograph artifacts in transparent materials such as ice. The artifacts, occurring in the surface, bulk, and interface, were generally 0.01 mm to 70 mm in size. Sample preparation, illumination, focusing and other technical problems are discussed in detail. Several sample photographs are included.
    Type of Medium: Series available for loan
    Pages: v, 36 Seiten , Illustrationen
    Series Statement: CRREL Report 76-40
    Language: English
    Note: CONTENTS Abstract Preface Summary Introduction Equipment The microscope system The camera system Tools for preparation of sample Laboratory procedure Categorizing artifact Choosing setup Preparing sample llluminating sample Photographing artifact Results Literature cited Selected bibliography Appendix. Reference information for photomacrographic and photo-micrographic applications
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  • 99
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-76/38
    In: CRREL Report, 76-38
    Description / Table of Contents: Current methods for evaluation of the moisture absorption of plastic insulations (ASTM-C-272-53 and ASTM-C-355-64) due to vapor pressure gradients or immersion rely on short time periods to predict long term performance. This procedure may not provide accurate information on performance since in practice insulations may absorb more moisture than these tests indicate. A series of tests were conducted on extruded polystyrene roof insulation that had been in place, exposed to environmental moisture and pressure gradients, for a maximum of 36 months. Results indicate that moisture absorption of 1.5% by volume can be expected in the field.
    Type of Medium: Series available for loan
    Pages: iv, 21 Seiten , Illustrationen
    Series Statement: CRREL Report 76-38
    Language: English
    Note: CONTENTS Abstract Preface Conversion factors: U.S. customary to metric (SI) units of measurement Introduction Principal features of a protected membrane roof system Reported advantages of a protected membrane roof system Study sites Stevens Hall, University of Alaska, Fairbanks Building 41 5, University of Alaska, Fairbanks Building 1053, Ft. Wainwright, Alaska Gruening Building, University of Alaska, Fairbanks Consortium Library and K Building, University of Alaska, Anchorage CRREL Laboratory, Hanover, New Hampshire Resources Building, University of Alaska, Fairbanks Insulation properties Sampling Results Bulksamples Sliced samples Conclusions and recommendations Literature cited Appendix A. Moisture contents Appendix B. Photographs
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  • 100
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-79/19
    In: CRREL Report, 79-19
    Description / Table of Contents: The critical velocities of loads moving over floating ice plates have been determined by several authors. In all these analyses it was assumed that the in-plane force field in the ice cover is zero. However, due to constrained thermal strains, in-plane forces do occur in the field. The purpose of the present paper is to determine their effect upon the critical velocities of the moving loads. It is shown that a uniform compression force field reduces the critical velocity, whereas a tension force field has the opposite effect.
    Type of Medium: Series available for loan
    Pages: ii, 12 Seiten , Illustrationen
    Series Statement: CRREL Report 79-19
    Language: English
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