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  • Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory  (183)
  • English  (183)
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  • 1985-1989  (53)
  • 1980-1984  (130)
  • 1955-1959
  • 1
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-83/29
    In: CRREL Report, 83-29
    Description / Table of Contents: A literature review indicated that the effects or permafrost on streambank erodibility and stability are not yet understood because systematic and quantitative measurements are seriously lacking. Consequently, general controversy exists as to whether perennially frozen ground inhibits lateral erosion and bankline recession, or whether it increases bank recession rates. Perennially frozen streambanks erode because of modification of the bank's thermal regime by exposure to air and water, and because of various erosional processes. Factors that determine rates and locations of erosion include physical, thermal and structural properties of bank sediments, stream hydraulics and climate. Thermal and physical modification of streambanks may also induce accelerated erosion within permafrost terrain removed from the immediate river environment. Bankline or bluffline recession rates are highly variable, ranging from less than 1 m/year to over 30 m/year and, exceptionally, to over 60 m/year. Long-term observations of the physical and thermal erosion processes and systematic ground surveys and measurements of bankline-bluffline recession rates are needed.
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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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  • 2
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    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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  • 3
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-82/33
    In: CRREL Report, 82-33
    Description / Table of Contents: Arctic sea ice is freckled with melt ponds during the ablation season; Antarctic sea ice has few, if any. On the basis of a simple surface heat budget, we investigate the meteorological conditions necessary for the onset of surface melting in an attempt to explain these observations. The low relative humidity associated with the relatively dry winds off the continent and an effective radiation parameter smaller than that characteristic of the Arctic are primarily responsible for the absence of melt features in the Antarctic. Together these require a surface-layer air temperature above 0 C before Antarctic sea ice can melt. A ratio of the bulk transfer coefficients C sub H/C sub E less than 1 also contributes to the dissimilarity in Arctic and Antarctic ablation seasons. The effects of wind speed and of the sea-ice roughness on the absolute values of C sub H and C sub E seem to moderate regional differences, but final assessment of this hypothesis awaits better data, especially from the Antarctic.
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    Pages: 16 Seiten , Illustrationen
    Series Statement: CRREL Report 82-33
    Language: English
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  • 4
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    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.
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    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-201-83/9
    In: CRREL Report, 83-9
    Description / Table of Contents: Recent observations of shore ice pile-up and ride-up along the coast of the Alaska Beaufort Sea are presented. Information is given to show that sea ice movement on shore has overridden steep coastal bluffs and has thrust inland over 150 m, gouging into and pushing up mounds of beach sand, gravel, boulders and peat and, inland, the tundra material. The resulting ice scar morphology was found to remain for tens of years. Onshore ice movements up to 20 m are relatively common, but those over 100 m are very infrequent. Spring is a dangerous time, when sea ice melts away from the shore, allowing ice to move freely. Under this condition, driving stresses of less than 100 kPa can push thick sea ice onto the land.
    Type of Medium: Series available for loan
    Pages: v, 59 Seiten , Illustrationen
    Series Statement: CRREL Report 83-9
    Language: English
    Note: Contents Abstract Preface Introduction Winter 1979-80 observations Winter 1980-81 and summer 1981 observations Winter 1981-82 and summer 1982 observations Old ice ride-up features Discussion Literature cited Appendix A. The boulder rampart and rock littered shore west of Konganevik Pt. Appendix B. Site location maps
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  • 6
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    Call number: ZSP-201-82/43
    In: CRREL Report, 82-43
    Description / Table of Contents: The radar signatures of ice wedges and wedge-like structures have been investigated for a variety of soil conditions. The radar used for this study emitted short sinusoidal pulses of about 10-ns duration with an approximate center frequency of 150 MHz. Most of the ice wedges existed at depths of about 1 m in a variety of silty and sandy soils with both frozen and thawed active layers. The position of the wedges was usually identified from corresponding surface features. An artificial ice wedge in coarse-grained alluvium was also profiled as well as wedge-like structures of fine silt in a coarse-grained glacial outwash. All wedges and wedge-like structures produced a hyperbolic reflection profile except when an active layer of thawed, saturated silt was present which eliminated returns from the wedges. The peaks of the hyper-bolas were sometimes masked by reflections from the permafrost table or other material interfaces, and multiple hyperbolas occurred at some sites. The dielectric constant of the host medium was often calculated from the linear portions of the hyperbolas and the results were verified by laboratory time domain reflectometry measurements per-formed on field samples. In some cases, hyperbolic profiles originated at several meters depth suggesting that deep ice wedges could be detected in areas of cold permafrost.
    Type of Medium: Series available for loan
    Pages: iv, 19 Seiten , Illustrationen
    Series Statement: CRREL Report 82-43
    Language: English
    Note: CONTENTS Abstract Preface Introduction Background Objectives and procedures Equipment used Radar TDR Definitions Massive ice Results Artificial wedge: Norwich, Vermont Ice wedges in sand: Fish Creek, Alaska Ice wedges: Prudhoe Bay, Alaska Ice wedges under thawed fine-grained soils: North Slope, Alaska Wedge-like soil structures: Ft. Greely, Alaska TDR measurements Summary and concluding remarks Literature cited Appendix A: Brief discussion of dispersion
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  • 7
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-82/41
    In: CRREL Report, 82-41
    Description / Table of Contents: Many of the important factors influencing the choice of appropriate aquifer test procedures are presented. The concepts of bias, accuracy and spatial variabil­ity are explained. The definitions of a number of aquifer parameters are devel­oped from basic principles demonstrating the underlying assumptions and limita­tions. The parameters considered are: piezometric head, hydraulic conductiv­ity/intrinsic permeability, flow direction, specific discharge magnitude, transmissivity, volumetric flow rate, total porosity, effective porosity, aver­age linear velocity, storage coefficient, specific yield, dispersion coefficient-aquifer dispersivity. For each parameter several techniques are described, evaluated and ranked in terms of perceived potential accuracy, simplicity and value to contaminant transport studies. It must be stressed, however, that the evaluations are based principally upon theoretical grounds, and not upon actual conduct of the described procedures.
    Type of Medium: Series available for loan
    Pages: iv, 111 Seiten , Illustrationen
    Series Statement: CRREL Report 82-41
    Language: English
    Note: CONTENTS Abstrac Preface Introduction Purpose Scope Concept of accuracy Test selection Definition of parameters Piezometric head Use of piezometers Hydraulic conductivity Flow direction Specific discharge magnitude Transmissivity Volumetric flow rate Porosity Average linear velocity Storage coefficient-specific yield Aquifer dispersivity Parameter estimation techniques Piezometric head Hydraulic conductivity Direction and magnitude of specific discharge vector Transmissivity Volumetric flow rate Total porosity Average linear velocity Storage coefficient Specific yield Effective porosity Aquifer dispersivity-dispersion coefficients Conclusions Literature cited
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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-201-82/40
    In: CRREL Report, 82-40
    Description / Table of Contents: The use of explosives to break floating ice sheets is described, and test data are used to develop design curves that predict explosives effects as ice thickness, charge size, and charge depth vary. Application of the curves to practical problems is illustrated by numerical examples. The general features of underwater explosions are reviewed and related to ice blasting. Quasi-static plate theory is considered, and is judged to be inapplicable to explosive cratering of ice plates. The specific energy for optimized ice blasting is found to compare quite favorably with the specific energy of icebreaking ships. All available field data for ice blasting are tabulated in appendices, together with details of the re­gression analyses from which the design curves are generated.
    Type of Medium: Series available for loan
    Pages: iv, 68 Seiten , Illustrationen
    Series Statement: CRREL Report 82-40
    Language: English
    Note: CONTENTS Abstract Preface Introduction General behavior of underwater explosions Regression analysis for ice-blasting data General features of the regression curves Use of the regression curves as design curves for ice blasting Row charges and pattern charges Response of floating ice sheets to underwater explosions Specific energy and “powder factor” Summary and conclusions Literature cited Appendix A: Basic data on ice blasting Appendix B: Scaled input data Appendix C: Initial regression analysis using complete polynomial Appendix D: Regression analysis with two coefficients of the original poly­nomial deleted
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  • 9
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    Call number: ZSP-201-83/18
    In: CRREL Report, 83-18
    Description / Table of Contents: An evaluation of an impulse radar system for detecting cavities under concrete pavement is discussed, and field results are presented. It was found that a dual antenna mode of surveying was ideal for void detection. In this mode one antenna operated in a transceive mode and a second, offset from the first, operated in a receive-only mode. This arrangement allowed a refraction-type profile survey to be performed, which enabled subpavement voids to be easily detected. Field trails were held at Plattsburgh Air Force Base, where 28 cavities were detected and mapped. Drilling of holes verified that a cavity existed and allowed cavity depth to be measured. The cavities varied from 1.5 in. to 23 in, depth and were up to 20 ft. long.
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    Pages: 49 Seiten , Illustrationen
    Series Statement: CRREL Report 83-18
    Language: English
    Note: CONTENTS Abstract Preface Introduction Plattsburgh Air Force Base Radar sounding system Survey procedure Cavity inspection Radar cavity detection test Radar profile results Falling-weight deflectometer tests Discussion and conclusions Literature cited
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  • 10
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-85/5
    In: CRREL Report, 85-5
    Description / Table of Contents: A dynamic-thermodynamic sea ice model is extended to include a full thermodynamic code and a complete multilevel ice thickness distribution. The variable thickness formulation includes a more realistic parameterization of ice ridging than used in previous models. Seasonal simulations have been performed using this model and the results have been analyzed with particular emphasis on examination of the ridge buildup results off the Canadian Archipelago and off the North Slope. This report presents a complete description of this model and discusses progress made on examining and testing the variable thickness extensions.
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    Pages: vi, 60 Seiten , Illustrationen
    Series Statement: CRREL Report 85-5
    Language: English
    Note: CONTENTS Abstract Preface Summary Introduction Description of the model Ice thickness equations Heat budget and oceanic boundary layer Analytic examination of the ridge redistribution process Theoretical framework Some specific redistributors Comparison to ridge morphological data Ice strength for different redistributors Numerical simulation results Basin-wide ice thickness and velocity characteristics Ice edge evolution and sensitivity Ice thickness characteristics off the Canadian Archipelago Comparison of observed and simulated ice drift Mass balance characteristics Concluding remarks Literature cited Appendix A: Mechanical redistributor Appendix B: Heat budget code Appendix C: Thickness finite difference code
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  • 11
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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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  • 12
    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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  • 13
    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.
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    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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  • 14
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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.
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    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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  • 15
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    Call number: ZSP-201-85/18
    In: CRREL Report, 85-18
    Description / Table of Contents: Concern over the environmental fate of explosives has brought about the development of sensitive analytical methods for measuring them in groundwater. In turn this concern has been extended to validating the sampling procedures for groundwater. This report addresses the potential effects of residual drilling muds on the analysis for explosive contaminants (TNT, DNT, RDX, and HMX) in monitoring wells. The approach was to determine sorption isotherms for each contaminant. Sorption appeared to be independent of solids concentration. Linear isotherms were obtained for RDX and HMX over a range of analytic concentrations; therefore, a single constant can be used to estimate the amount sorbed when the solution concentration is known. Isotherms for TNT and DNT were not linear, however. Scatchard analysis suggested that the isotherms for these analytes could be resolved into two predominant components: a linear component above a certain sorbed quantity and a Langmuir-type component below this quantity. The experimental data were fitted by regression analysis using the appropriate model. The equations developed can be used to predict the sorbed fraction (analytical bias) for any combination of solids and analyte concentration. The amounts of bentonite found in some existing wells do not appear to be sufficient to cause significant bias in analyses for these explosive contaminants.
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    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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  • 16
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    Call number: ZSP-201-84/17
    In: CRREL Report, 84-17
    Description / Table of Contents: VHF-band radiowave short pulses were transmitted within the permafrost tunnel at Fox, Alaska, over distances between 2.2 and 10.5 m. The propagation medium was a frozen silt containing both disseminated and massive ice with temperatures varying from -7°C near the transmitter to probably -2 C near the center of the tunnel overburden. The short pulses underwent practically no dispersion in the coldest zones but did disperse and refract through the warmer overburden, as suggested by calculations of the effective dielectric constant. Most significantly the measured frequency content decreased as the effective dielectric constant increased. The results indicate that deep, cross-borehole pulse transmissions over distances greater than 10 m might be possible, especially when the ground is no warmer than -4°C. The information thus pined could be used for identifying major subsurface variations, including ground ice features.
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    Pages: ii, 14 Seiten , Illustrationen
    Series Statement: CRREL Report 84-17
    Language: English
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  • 17
    Call number: ZSP-201-84/16
    In: CRREL Report, 84-16
    Description / Table of Contents: Phase composition curves are presented for a typical saline silt from Lanzhou, P.R.C., and compared to some silts from Alaska. The unfrozen water content of the Chinese silt is much higher than that of the Alaskan silts due to the large amount of soluble salts present in the silts from China, which are not present in silt from interior Alaska. When the salt is removed, the unfrozen water content is then similar for both the Chinese and Alaskan silt. Here we introduce a technique for correcting the unfrozen water content of partially frozen soils due to high salt concentrations. We calculate the equivalent molality of the salts in the unfrozen water at various temperatures from a measurement of the electrical conductivity of the extract from saturated paste.
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    Pages: iii, 25 Seiten , Illustrationen
    Series Statement: CRREL Report 84-16
    Language: English
    Note: Contents Abstract Preface Introduction Background Materials Sample preparation Nuclear magnetic resonance Specific surface area Electrical conductivity Results and discussion Summary Literature cited Appendix A: Unfrozen water content vs temperature data for Lanzhou silt
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  • 18
    Call number: ZSP-201-86/3
    In: CRREL Report, 86-3
    Description / Table of Contents: Experiments to study the melting of a horizontal ice sheet with a flow of water above it were conducted in a 35 m long refrigerated flume with a cross section of 1.2x1.2 m. Water depth, temperature, and velocity were varied as well as the temperature and initial surface profile of the ice sheet. The heat transfer regimes were found to consist of forced turbulent flow at high Reynolds numbers with a transition to free convection heat transfer. There was no convincing evidence of a forced laminar regime. The data were correlated for each of the regimes, with the Reynolds number, Re, or the Grashof number combined with the Reynolds number as Gr/Re to the 2.5 power used to characterize the different kinds of heat transfer. For water flowing over a horizontal ice sheet, the melting heat flux, for low flow velocities, was not found to drop below the value for the free convection case-488.5 W/sq m-as long as the water temperature exceeds 3.4 C. This is significant since the free convection melt values far exceed those for laminar forced convection. At the low flow velocities, the melting flux was not dependent upon the fluid temperature until the water temperature dropped below 3.4 C, when q sub c = 135.7 (Delta T). In general, the heat transfer was found to significantly exceed that of non-melting systems for the same regimes. This was attributed to increased free stream turbulence, thermal instability due to the density maximum of water near 4 C, and the turbulent eddies associated with the generation of a wavy ice surface during the melting.
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    Pages: vii, 85 Seiten , Illustrationen
    Series Statement: CRREL Report 86-3
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Non-melting heat transfer relations for horizontal surfaces Heat transfer for melting horizontal ice sheets Instrument setup, data acquisition and test procedures General Instrumentation Data acquisition Computer software Test procedures Data output from computer Equations used for data analysis Control volume and melting surface Control of variables Error analysis Experimental results and discussion Wave formation Temperature and velocity profiles in open channel flow Correlation of data Summary Literature cited Appendix A: Conversion equations for data acquisition equipment Appendix B: Computer code for data acquisition and analysis Appendix C: Typical test output Appendix D: Thermal properties of water and ice Appendix E: Error analysis Appendix F: Summary of test conditions Appendix G: Experimental data and calculated quantities, with inlet length
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  • 19
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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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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  • 20
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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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  • 21
    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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  • 22
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    Call number: ZSP-201-87/10
    In: CRREL Report, 87-10
    Description / Table of Contents: Uniaxial constant-stress and constant-strain-rate compression tests were conducted on more than 200 remolded, saturated, frozen specimens of Fairbanks silt under various conditions. A series of curves of stress vs strain rate for various temperatures of strain rates ranging from about 6x10-2 to 10-8s-1show a close strength correspondence between the constant-stress and-costant strain-rate tests. All of these "complete" stress vs strain rate curves could not be described by a single power law or exponential equation, indicating that different deformation mechanisms are dominant within different ranges of strainrate Two critical strain rates for distinguishing between the different deformation mechanisms were ob-served to be near 10- 3 and 10-6 s-1 for the medium-dense frozen Fairbanks silt. The former indicates the transition from ductile failure to moderate brittle fracture as strain rate increases, while the latter indicates the transition from dislocation creep to glide creep (by the authors' definition). Based on the change in flow law, two fundamental creeps were classified: short-term creep, which is governed by glide creep, and long-term creep, which is governed by dislocation creep. The failure criterion of frozen silt has a general form of em x tm = Ef, where m depends only on density, and tm is in minutes if m is not 1. The failure strain Ef was not sensitive to temperature and strain rate over a certain range of strain rates, but it was very sensitive to density. Assur's creep model (1980) for ice was used to fit the creep data in this study. It works well for short-term creep but does not fit as well for long-term creep. The rate process theory was applied to the creep data. A very high value of experimental activation energy was obtained for lower stresses, and a very high value of apparent activation energy was observed for higher temperatures. The peak compressive strength was very sensitive to temperature and strain rate but relatively insensitive to density. While the initial tangent modulus is not-sensitive to strain rate, it increases with decreasing temperature and density.
    Type of Medium: Series available for loan
    Pages: vi, 75 Seiten , Illustrationen
    Series Statement: CRREL Report 87-10
    Language: English
    Note: CONTENTS Abstract Preface Introduction Review of previous work Specimen preparation Material Molding Testing procedure and apparatus Test results Definition of strain and stress Definition of creep failure Definition of failure in constant-strain-rate tests Definition of initial yield strength Determination of initial tangent modulus and 50% peak strength modulus Creep behavior General nature of the creep process and the failure mode Minimum creep rate Time to creep failure Relationship between t, and tm Creep failure strain and failure criterion Creep model and prediction of creep strain Strength behavior General stress-strain behavior and failure mode Peak compressive strength Initial yield strength Failure strain Initial yield strain Initial tangent modulus 50% peak strength modulus Correspondence between constant-stress tests and constant-strain-rate tests Conclusions Literature cited Appendix A: Unfrozen water content data Appendix B: Physical properties of samples tested
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  • 23
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    Call number: ZSP-201-89/19
    In: CRREL Report, 89-19
    Description / Table of Contents: Recent efforts to improve airborne electromagnetic induction- measurement technology and to downsize the related helicopter-towed antenna assembly from about 7.5 m long to about 3.5 m long for use in airborne measurement of sea ice thickness are discussed, as are the results from arctic field testing. Also outlined are the system noise and drift problems encountered during arctic field evaluation, problems that adversely affected the quality of the sounding data. The sea ice sounding results indicate that it should be possible to determine thickness to within 5% for ice floes with moderate relief but that, because of sounding footprint size and current model algorithm constraints, steepsided pressure ridge keels cannot be well defined. The findings also indicate that routine sea ice thickness profiling from an airborne platform is close at hand with further system improvement, as is the apparent capability to determine the conductivity of the sea ice, from which an assessment of sea ice strength can be made.
    Type of Medium: Series available for loan
    Pages: iii, 54 Seiten , Illustrationen
    Series Statement: CRREL Report 89-19
    Language: English
    Note: CONTENTS Abstract Preface Introduction Pre-field-deployment activities Software development System optimization Improvements of the calibration procedure Real-time processing Small bird design and implementation Other improvements Field activities Snow, ice and seawater data AEM surveys Calibration AEM data processing Post-survey results Processing problem Ground truth data Floe freeboard vs thickness analysis AEM sounding results Concluding remarks Literature cited Appendix A: Blowup of Figure 28
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  • 24
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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.
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    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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  • 25
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    Call number: ZSP-201-80/27
    In: CRREL Report, 80-27
    Description / Table of Contents: No general, analytical solution exists for phase change around a cylinder, thus, approximate methods have been evaluated. The heat balance integral technique applied to the cylinder gave excellent results when compared to published numerical solutions. Graphical solutions are given for phase change about a cylinder for ranges of the Stefan number, superheat parameter, and property value ratios for typical soils. An approximate, general solution has been derived which is reasonably accurate and can be used for any values of the above-mentioned parameters. The effective thermal diffusivity method has been shown to be useful for practical problems of phase change.
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    Pages: v, 18 Seiten , Illustrationen
    Series Statement: CRREL Report 80-27
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Zero superheat Constant phase change rate Zero sensible heat Finite sensible heat Finite superheat Quasi-steady solution Heat balance integral solution Approximate methods Conclusions Literature cited
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  • 26
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    Call number: ZSP-201-80/25
    In: CRREL Report, 80-25
    Description / Table of Contents: Two new types of load cells for attachment to bridge piers and direct measurement of ice forces were developed and tested with one type being installed on a pier of the Yukon River Bridge northwest of Fairbanks, Alaska. Both types of load cells used beams supported by base plates and carried nose plates that were loaded by the ice. The loads were imposed at the beams at locations differing from the support reactions so that the loads developed moments in the beams. By instrumenting them with strain gauges, the loads could be measured. Details of the design of the load cells, the means of calculating the loads and experience obtained with load cells are discussed.
    Type of Medium: Series available for loan
    Pages: iii, 17 Seiten , Illustrationen
    Series Statement: CRREL Report 80-25
    Language: English
    Note: CONTENTS Preface Conversion factors Introduction Estimates and field measurements of ice forces on structures General Indirect estimates Direct measurements Small-scale and laboratory studies Instrumentation plan for measuring ice loads on the Yukon River Bridge Load cell development The single reaction beam system Performance of a single reaction beam load cell The double reation beam load cell Reaction beam design Stress in the beam Deflection Axial tensile stress in the reaction beam Measurement techniques Conclusions Literature cited Appendix A. Finding load magnitude and location with a single reaction beam device Appendix B. Finding load magnitude and location on a double reaction beam device
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  • 27
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    Call number: ZSP-201-80/26
    In: CRREL Report, 80-26
    Description / Table of Contents: A vital concern to the survivability of hardened underground structures in rock is the relative displacement induced along geologic discontinuities by nearby explosions. Such displacement, commonly termed block motion, can occur along faults, joints, bedding planes and other structural weaknesses in rock. This report documents all occurrences of block motion observed during the development of DIHEST, a series of shallow-buried high explosive experiments designed to simulate the direct induced ground motions from a nuclear surface burst. Instances of block motion are described, along with pertinent details of the explosive arrays, geology and ground motion fields. The influence of these and other factors on the direction and magnitude of block motion is discussed.
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    Pages: vi, 62 Seiten , Illustrationen
    Series Statement: CRREL Report 80-26
    Language: English
    Note: CONTENTS Abstract Preface Conversion factors Introduction STARMET Test description Test results PLANEWAVE II Test description Test results DATEX II Test description Test results HANDEC II Test description Test results ROCKTEST II Test description Test results Summary and discussion Literature cited
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  • 28
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    Call number: ZSP-201-80/24
    In: CRREL Report, 80-24
    Description / Table of Contents: The fluid shear stress applied to the underside of a simulated floating ice cover was measured in a laboratory flume. The measured values were compared with values of the shear stress computed from the von Karman-Prandtl velocity distribution fitted to the velocity profiles measured beneath the cover. For the lower velocity runs (approx 0.079 m/s) the measured and computed values of the shear stress were in close agreement. At the high velocity flows (approx 0.137 m/s) the measured values were roughly one-half those calculated from the velocity distribution. As the underside of the cover became increasingly rougher, the position of maximum velocity moved closer to the bottom of the channel. It was shown that the Darcy friction coefficient is exponentially related to a normalized ice cover thickness, which suggests that it is measure of the roughness of a fragmented ice cover.
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    Pages: iv, 11 Seiten , Illustrationen
    Series Statement: CRREL Report 80-24
    Language: English
    Note: CONTENTS Abstract Preface List of symbols Introduction Experimental apparatus Experimental procedures Analysis of forces Experimental results Analysis of data Conclusions Literature cited
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  • 29
    Call number: ZSP-201-80/20
    In: CRREL Report, 80-20
    Description / Table of Contents: Results of impulse radar studies of sea ice give support to the concept of a sea ice model in which the ice bottom is composed of an array of lossy parallel plate waveguides. The fundametal relation between the average bulk brine volume of sea ice and its electrical and strength properties is discussed as is the remote detection of under-ice current alignment. It was found that 1) the average effective bulk dielectric constant is dependent upon the average bulk brine volume of the sea ice; 2) sea ice anisotropy, arising from a bottom structure of crystal platelets with a preferred c-axis horizontal alignment, can be detected by radio echo sounding measurements made not only on the ice surface but also from an airborne platform; 3) the effective coefficient of reflection from the seaiIce bottom decreases with increasing average effective bulk dielectric constant of the ice, decreases with increasing bulk brine volume, and is typically one to two orders of magnitude lower dhan the coefficient of reflection from the ice surface; and 4) the losses In sea ice increase with increasing average bulk brine volume.
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    Pages: v, 18 Seiten , Illustrationen
    Series Statement: CRREL Report 80-24
    Language: English
    Note: CONTENTS Abstract Preface Introduction Field program Results and discussion Conclusions Literature cited Appendix: Data analysis procedures
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  • 30
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    Call number: ZSP-201-80/18
    In: CRREL Report, 80-18
    Description / Table of Contents: The use of ice as a structural material is common practice for certain applications in cold regions. Techniques such as surface flooding or water spraying are used to accelerate ice growth rates, thereby lengthening the winter construction season. This report examines the heat and mass transfer rates from freely falling water drops in cold air. Design equations which predict the amount of supercooling of the drops as a function of outdoor ambient temperature, drop size and distance of fall are given
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    Pages: v, 14 Seiten , Illustrationen
    Series Statement: CRREL Report 80-18
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Velocity problem Heat and mass transfer problem - A single drop Heat and mass transfer - A system of drops Literature cited Appendix A: FORTRAN IV program to calculate final drop temperature, air temperatureand humidity
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  • 31
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    Call number: ZSP-201-80/8
    In: CRREL Report, 80-8
    Description / Table of Contents: This report presents the results of the tests on the new U.S. Coast Guard 140-ft icebreaker Katmai Bay (WTGB-101) in the level plate ice and brash ice in Whitefish Bay and the St. Marys River. The results indicate that the vessel can penetrate 22 in. of level freshwater ice with 2-3 in. of snow cover. It can also penetrate up to 48 in. of brash ice in a continuous mode and at least 30 in. of plate ice by backing and ramming. The installed bubbler system decreased the required power of the vessel from 10 to 30% in brash ice and 25 to 35% in level ice. The low friction coating appears to be effective in decreasing the friction factor when it remains intact; when it peels off it appears to make conditions worse than plain paint. An average dynamic friction factor of 0.15 could be used over the entire hull for these tests.
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    Pages: iv, 28 Seiten , Illustrationen
    Series Statement: CRREL Report 80-8
    Language: English
    Note: CONTENTS Abstract Preface Metric conversion table Introduction Roughness and friction measurements Level plate ice performance Brash ice performance Ramming icebreaking performance Analysis of the data Propulsion efficiency in ice Regression analysis Conclusions and recommendations Literature cited
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  • 32
    Call number: ZSP-201-80/10
    In: CRREL Report, 80-10
    Description / Table of Contents: A mathematical model of coupled heat and moisture flow in soils has been developed. The model includes algorithms for phase change of soil moisture and frost heave and permits several types of boundary and initial conditions. The finite element method of weighted residual (Galerkin procedure) was chosen to simulate the spatial regime and the Crank-Nicholson method was used for the time domain portion of the model. To facilitate evaluation of the model, the heat and moisture fluxes were essentially decoupled; moisture flux was then simulated accurately, as were heat flux and frost heave in a laboratory test. Comparison of the simulated and experimental data illustrates the importance of unsaturated hydraulic conductivity. It is one parameter which is difficult to measure and for which only a few laboratory test results are available. Therefore, unsaturated hydraulic conductivities calculated in the computer model may be a significant source of error in calculations of frost heave. The algorithm incorporating effects of surcharge and overburden was inconclusively evaluated. Time-dependent frost penetration and frost heave in laboratory specimens were closely simulated with the model. After 10 days of simulation, the computed frost heave was about 2.3 cm vs 2.0 cm and 2.8 cm in two tests. Frost penetration was computed as 15 cm and was measured at 12.0 cm and 12.2 cm in the two laboratory samples after 10 days.
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    Pages: v, 49 Seiten , Illustrationen
    Series Statement: CRREL Report 80-10
    Language: English
    Note: CONTENTS Abstract Preface Introduction One-dimensional equations of simultaneous heat and moisture flux Moisture transport Heat transport Phase change Coupling effects Frost heave algorithm Development of computer model Finite difference vs finite element method Finite element formulation Time domain solution Evaluation of the mathematical model Heat flux Moisture flux Numerical dispersion Frost heave of homogeneous laboratory samples Conclusions Recommended studies to refine the model Literature cited Appendix A. Work plan, staffing and instrumentation requirements for correlating results oflaboratory frost susceptibility tests with field performance Appendix B. Proposed investigation of thaw weakening of subgrade soil and granular unboundbase course Appendix C. Derivation of finite element system matrices
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  • 33
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    Call number: ZSP-201-81/13
    In: CRREL Report, 81-13
    Description / Table of Contents: Electrical properties of frozen ground were measured using radio frequency interferometry (RFI) in the very high frequency (VHF) radiowave band. Ice-rich organic silts and sands and gravels of variable ice content were investigated during early April of both 1979 and 1980. Frequencies between 10 and 150 MHz were used with best results obtained between 40 and 100 MHz. Surface impedance and magnetic induction techniques were also used to obtain an independent measure of low frequency resistivity and to obtain a separate control on vertical inhomogeneity. Soil samples were tested for organic and water content. The dielectric constants determined for the ice-rich organic silts ranged from 4.0 to 5.5 while those for the sands and gravels were about 5.1. Dielectric loss was due to d.c. conduction and was very low for the silts but significant for the sands and gravels. The higher values for the sands and gravels were most likely due to the higher concentrations of salt that are reported to exist in the old beach ridges in this region. All the RFI measurements are believed to be indicative of only the first few meters of the ground although the radiowaves could penetrate to tens of meters.
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    Pages: iv, 18 Seiten , Illustrationen
    Series Statement: CRREL Report 81-13
    Language: English
    Note: CONTENTS Abstract Preface Introduction Background Objectives and procedures Theory and instrumentation Radio frequency interferometry Case 1: Homogeneous ground model Case 2: Two-layer ground model RFI instrumentation Low frequency methods Point Barrow sites Results and discussion Site 1: Tundra Site 2: Beach ridge Site 3: Marsh Conclusions Literature cited Appendix A: Discussion of low-frequency geophysical methods
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  • 34
    Call number: ZSP-201-81/15
    In: CRREL Report, 81-15
    Description / Table of Contents: This report analyzes the results of a field study previously reported by Scrivner et al. (1969) for the National Cooperative Highway Research Program. These authors studied the seasonal pavement deflection characteristics of 24 test sites on roads in service in regions with freezing indexes ranging from 100 F-days to 2100 F-days. They used the Dynaflect cyclic pavement loading device to determine the pavement system response. Of specific interest to my analysis was the increased pavement deflection after freezing and thawing and the time to recovery of normal deflection characteristics. These characteristics were related to soil and climatic factors using statistical techniques. The most significant observations of this statistical analysis are: (1) that the freezing index is not a significant parameter in determining the percent increase in pavement deflection during thawing, and (2) that the recovery time is inversely proportional to the depth of freezing. As was expected, the most significant variable affecting the increase in pavement deflection was the frost susceptibility classification. This observation reinforces the necessity for careful selection of soil materials used in pavement systems.
    Type of Medium: Series available for loan
    Pages: v, 10 Seiten , Ilustrationen
    Series Statement: CRREL Report 81-15
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Description of test site Test results Method of analysis Results of analysis Change in resilient deflection due to thawing, A Recovery time after onset of thawing, t20 Discussion of results Change in resilient deflection due to thawing, A. Recovery time after thawing, t20 Conclusions Literature cited ILLUSTRATIONS Figure Pavement deflection and frost penetration vs time Data points and regression line for A and t2 0 versus F Data points and regression line for A and t2 0 versus W Data points and regression line for A and t2 0 versus I Data points and regression line for A and t20 versus N Data points and regression line for A and t20 versus D Data points and regression line for t20 versus A Permeability vs void ratio for the Toledo Penn 7 material TABLES Properties of test sections Test results from Scrivner et al Results of regression analysis
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  • 35
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    Call number: ZSP-201-81/18
    In: CRREL Report, 81-18
    Description / Table of Contents: During the growing seasons of 1977, 1978, and 1979, revegetation techniques were studied on the Chena River Lakes Project, a flood control dam and levee near Fairbanks, Alaska, to find an optimal treatment for establishing permanent vegetation cover on the gravel structures. The treatments tested on plots at the dam andor levee involved three main variables 1 vegetation grass and clover seed andor willow cuttings, 2 mulch, mulch blanket, andor sludge, and 3 substrate gravel or fine-grained soil over the gravel base. The mulches were hay, wood-cellulose-fiber, peat moss, and Conwed Hydro Mulch 2000, which is a wood-cellulose-fiber mulch with a polysaccharide tackifier. A constant rate of fertilizer was applied to all plots except the control. A section of each plot was refertilized again in their third growing season to compare annual and biannual fertilization. The high fertilization rate produced above-average growth. Fescue, brome, and foxtail were the most productive species on the dam, while alsike cover was the most productive on the wetter levee site. When grass seed and willow cuttings were planted at the same time, willow survival and growth were reduced. Fertilization is required for at least two years to produce an acceptable permanent vegetation cover, although fine- grained soil or sludge reduces the amount of fertilizer needed in the second year. Third-year fertilization may not be necessary since the benefits of the second fertilization continue for at least two years. A sludge treatment refertilized during its second growing season produces the highest biomass recorded in this study.
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    Pages: ix, 59 Seiten , Illustrationen
    Series Statement: CRREL Report 81-18
    Language: English
    Note: CONTENTS Abstract Preface Abbreviations Conversion factors Summary Introduction Background Site characterization Climate Purpose Materials and methods General Moose Creek Dam site Tanana Levee site Sampling and measurement Abiotic controls on vegetation Meteorological data Soil moisture as a limiting factor Soil chemical analysis Vegetation growth and survival Moose Creek Dam site Tanana Levee site Biomass by species Roof penetration Seedling density of invading woody species Weeds Supplemental observations Sediment loss Sludge and runoff-water composition Cost analysis Conclusions Literature cited Appendix A: 1977 grass growth on 1977 dam treatments Appendix B: 1978 grass growth on 1977 dam treatments Appendix C: 1979 grass growth on 1977 dam treatments Appendix D: Grass growth on 1978 dam treatments Appendix E: 1977, 1978, and 1979 survival of willow treatments Appendix F: Grass growth on Tanana levee treatments Appendix C: Chemical analysis of sludge and runoff water
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  • 36
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    Call number: ZSP-201-84/2
    In: CRREL Report, 84-2
    Description / Table of Contents: Investigations of the in situ complex dielectric constant of sea ice were made using time-domain spectroscopy. It was found that (1) for sea ice with a preferred horizontal crystal c-axis alignment, the anisotropy of polarizing properties of the ice increased with depth, (2) brine inclusion conductivity increased with decreasing temperature down to about -8 C, at which point the conductivity decreased with decreasing temperature, (3) the DC conductivity of sea ice increased with increasing brine volume, (4) the real part of the complex dielectric constant is strongly dependent upon brine volume but less dependent upon the brine inclusion orientation, (5) the imaginary part of the complex dielectric constant was strongly dependent upon brine inclusion orientation but much less dependent upon brine volume. Because the electromagnetic (EM) properties of sea ice are dependent upon the physical state of the ice, which is continually changing, it appears that only trends in the relationships between the EM properties of natural sea ice and its brine volume and brine inclusion microstructure can be established.
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    Pages: vi, 38 Seiten , Illustrationen , 1 Beilage
    Series Statement: CRREL Report 84-2
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Dielectric properties of sea ice Time-domain spectroscopy measurement Laboratory measurements Field measurements Analysis of ladder data Conductivity of brine and sea ice Complex dielectric constant of brine and sea ice Discussion and conclusions Literature cited
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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-201-84/4
    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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  • 38
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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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  • 39
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-84/5
    In: CRREL Report, 84-5
    Description / Table of Contents: Diatom species composition and relative abundances were determined for ice cores obtained from Weddell Sea pack ice during the October-November 1981 Weddell Polynya Expedition (WEPOLEX). Ice thickness and salinity indicate that the ice was less than one year old. The predominant ice type (70%) was frazil, which has the capacity to mechanically incorporate biological material through nucleation and scavenging. Diatoms were found throughout the length of the cores. Species showed down-core fluctuations in abundance that appeared to be correlated with changes in ice type. Pennate forms were more abundant than centrics, the average ratio being 16:1. Diatom frustules with intact organic material were more abundant (5 billion cells/liter). Differences in species abundances are attributed initially to incorporation of algal cells from a temporally changing water column and subsequently to diatom reproduction within the ice. Scanning electron micrographs illustrating the morphologic characteristics of the predominant species are included.
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    Pages: iv, 46 Seiten , Illustrationen
    Series Statement: CRREL Report 84-5
    Language: English
    Note: Contents Abstract Preface Introduction Materials and methods Results Discussion Conclusions Literature cited Appendix A: Taxonomic terms Appendix B: Differences in species composition and abundance in duplicate samples examined under optical and inverted light microscopes Appendix C: Morphologic descriptions and SEM micrographs
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  • 40
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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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  • 41
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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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
    Type of Medium: Series available for loan
    Pages: iv, 22 Seiten , Illustrationen
    Series Statement: CRREL Report 84-7
    Language: English
    Note: CONTENTS Abstract Preface Introduction Experiments Test flume facility Experimental apparatus Experimental procedure Results Plastic versus freshwater ice Shoreline forces Boom forces Average shear stress under ice cover Internal forces Discussion Data scatter Summary and conclusions Literature cited Appendix A: Experimental results
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  • 42
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-82/30
    In: CRREL Report, 82-30
    Description / Table of Contents: Equations are developed that can be used to determine the amount of gas present in sea ice from measurements of the bulk ice density, salinity and temperature in the temperature range o f-2 to -30°C. Conversely these relationships can be used to give the density of sea ice as a function of its temperature and salinity, considering both the presence of gas and of solid salts in the ice. Equations are also given that allow the calculation of the gas and brine volumes in the ice at temperatures other than that at which the bulk density was determined.
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    Pages: 13 Seiten , Illustrationen
    Series Statement: CRREL Report 82-30
    Language: English
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  • 43
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-83/8
    In: CRREL Report, 83-8
    Description / Table of Contents: In the course of model tests with urea-doped ice in the CRREL Ice Engineering Facility test basin, the growth process and the physical and mechanical properties of the model ice were investigated. The parameters which were varied were: urea concentration in the tank water, air temperature during growth, growth duration, and tempering time. Uniformity of ice thickness and ice mechanical properties over the whole tank area were found to be satisfactory. The structure of the urea-doped ice was found to be similar to that of the ice except for a relatively thick incubation layer over a dendritic bottom layer. Empirical relationships were established between: ice thickness and negative degree-hours; mechanical properties and growth temperature, urea concentration, and ice thickness; and reduction in mechanical properties and tempting time. The results of the study are presented in charts which permit reliable scheduling of model tests with required ice thickness and ice flexural strength.
    Type of Medium: Series available for loan
    Pages: vii, 53 Seiten , Illustrationen
    Series Statement: CRREL Report 83-8
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Experimental facility and procedures Ice test basin Ice growth procedure Measurements Ice growth and structure Ice thickness distribution Ice growth during freeze-up Ice growth during warm-up Structure of urea-doped ice Mechanical properties of urea-doped ice Introductory remarks Model of a two-layer elastic material Properties of urea-doped ice during freeze-up Properties of urea-doped ice during warm-up Applications to test program scheduling Summary and conclusions Literature cited Appendix A: Results of ice thickness measurements for various growth conditions Appendix B: Properties of untempered ice Appendix C: Properties of tempered ice
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  • 44
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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.
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    Pages: iii, 16 Seiten , Illustrationen
    Series Statement: CRREL Report 83-6
    Language: English
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  • 45
    Call number: ZSP-201-86/13
    In: CRREL Report, 86-13
    Description / Table of Contents: Stress-deformation data for six granular soils ranging from sandy silt to dense-graded crushedstone were obtained from in-situ tests and laboratory tests. Surface deflections were measured in the in-situ tests, with repeated-load plate-bearing and falling-weight deflectometer equipment, when the six granular soils were frozen, thawed, and at various stages of recovery from thaw weakening. The measured deflections were used to judge the validity of procedures developed for laboratory triaxial tests to determine nonlinear resilient moduli of specimens in the frozen, thawed, and recovering states. The validity of the nonlinear resilient moduli, expressed as functions of externally applied stress and moisture tension, was confirmed by using the expressions tocalculate surface deflections that were found to compare well with deflections measured in the in-situ tests. The tests on specimens at various stages of recovery are especially significant because they show a strong dependence of the resilient modulus on moisture tension, leading to the conclusion that predictions or in-situ measurements of moisture tension can be used to evaluate expected seasonal variation in the resilient modulus of granular soils.
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    Pages: iv, 148 Seiten , Illustrationen
    Series Statement: CRREL Report 86-13
    Language: English
    Note: CONTENTS Abstract Preface Introduction Test sections Installing instruments and sampling Laboratory tests Asphalt concrete Base, subbase and subgrade soils Data analysis for base, subbase and subgrade soils Field tests Analysis of plate loading tests Analytical approach Results Discussion Conclusions Literature cited Appendix A: Field data Appendix B: Ground temperatures, moisture tension, water table and freezing iso-therms prevailing during plate loading tests Appendix C: Measured surface deflections compared with deflections calculated by NELAPAV Appendix D: Resilient moduli and supporting data calculated by NELAPA V at radius 0.0, taxiways A and B.
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  • 46
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-85/1
    In: CRREL Report, 85-1
    Description / Table of Contents: An expensive drill has been modified to provide researchers with the ability to auger an open hole or to acquire continuous, undisturbed 76-mm-diam core samples of a variety of perennially frozen materials that are suitable for chemical and petrographic analysis. It was developed by field testing in support of research from 1980 to 1983. Operation of the drill is based mainly on using a minimum of power to cut through frozen ground with tungsten carbide cutters on a CRREL coring auger. The ice content, temperature and grain size of the frozen sediments are important variables determining the sampling depth. Perennially frozen sediments with temperatures in the range of -0.5 C to -8.5 C have been continuously cored with this drill. Drilling and sampling are most efficiently conducted when ambient air temperatures are below freezing and the active layer is frozen. The self-contained lightweight drill is readily transportable off-road by helicopter or tracked vehicle, or by towing over roads. It is locally self-mobile by use of a winch. Total cost of the drill and modifications is estimated at approximately $10,000.
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    Pages: v, 34 Seiten , Illustrationen
    Series Statement: CRREL Report 85-1
    Language: English
    Note: CONTENTS Abstract Preface Introduction Background on development Drill development and configuration Equipment Modifications Operations Assembly and disassembly Field transport and movement Typical operating procedures Effect of material properties, weather and water Depth and hole completion time Summary Literature cited
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  • 47
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-84/33
    In: CRREL Report, 84-33
    Description / Table of Contents: A small-scale experimental study was conducted to characterize the magnitude and nature of ice forces during continuous crushing of ice against a rigid, vertical, cylindrical structure. The diameter of the structure was varied from 50 to 500 mm, the relative velocity from 10 to 210 mm/s, and the ice thickness from 50 to 80 mm. The ice tended to fail repetitively, with the frequency of failure termed the characteristic frequency. The characteristic frequency varied linearly with velocity and to a small extent with structure diameter. The size of the damage zone was 10 to 50% of the ice thickness, with an average value of 30%. The maximum and mean normalized ice forces were strongly dependent on the aspect ratio (structure diameter/ice thickness). The forces increased significantly with decreasing aspect ratio, but were constant for large aspect ratios. The maximum normalized forces appeared to be independent of strain rate. The effect of velocity on the normalized ice forces depended on structure diameter. The mean effective pressure or specific energy of ice crushing depended on both aspect ratio and ice-structure relative velocity. The energy required to crush the ice for the one failure cycle was obtained from the ice force records for each test, and was compared to the energy calculated from an idealized sawtooth shape for the force record, the maximum force, velocity and characteristic frequency data. Originator - supplied keywords included: Cold regions, Cold regions construction, Cylindrical test structures, Ice, Ice crushing, Ice forces, and Test facilities.
    Type of Medium: Series available for loan
    Pages: vi, 47 Seiten , Illustrationen
    Series Statement: CRREL Report 84-33
    Language: English
    Note: Contents Abstract Preface Nomenclature Introduction Test objectives Experimental setup and procedures Facilities Test fixture Data acquisiton system Ice sheets Measurement of ice properties Daily test summary Experimental results and discussion Observations Ice force records Frequency of ice force variations Discussion Maximum crushing forces Mean effective pressure or specific energy of ice in crushing Failure energy of ice Ratio of maximum force to mean force Summary and conclusions Literature cited Appendix A: Data for continuous crushing tests
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  • 48
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-85/3
    In: CRREL Report, 85-3
    Description / Table of Contents: In the past all theoretical analyses for rapidly sheared granular flows assumed that the granular solids are either disks or spheres and are uniform in size. However, natural materials that create these granular flows are in general irregular in shape and have various spectra of sizes. The stress and rate of energy dissipation levels in granular flows are significantly influenced by the size distribution. In part 1 of this report series (AD-A154 045), the formulation of the constitutive equations considering a two-size granular mixture is presented, where the ratio of the two sizes is nearly one. In part 2, the constitutive equations for a two-size mixture are extended to include a general size ratio. In addition, a complete spectrum of size distribution is incorporated, which allows the quantification of the size distribution effect in the most general way. In analyzing the stresses, intergranular collision is assumed to be the major dynamic activity at the microscopic level. Because of the present limited knowledge of testing shape effects, the analysis is confined to the flow of either disks or spheres. The result of this work provides necessary information for a more realistic analysis of natural and industrial granular flow. Keywords: Granular flow, and Particle size distribution.
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    Pages: vi, 29 Seiten , Illustrationen
    Series Statement: CRREL Report 85-3
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Constitutive equations for a two-size mixture Limiting case of the two-size mixture Complete spectrum analysis for spheres and disks Conclusion Literature cited Appendix A: Derivation of collision frequency between neighboring spheres that follow the mean shear flow without fluctuations
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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-201-83/12
    In: CRREL Report, 83-12
    Description / Table of Contents: This paper documents the development and verification of two finite difference models that solve the general two-dimensional form of the heat conduction equation, using the alternative-direction implicit method. Both can handle convective, constant flux, specified temperature and semi-infinite boundaries. The conducting medium may be composed of many materials. The first program, ADI, solves for the case where no change of state occurs. ADIPC solves for case where a freeze/thaw change of phase may occur, using the apparent heat capacity method. Both models are verified by comparison to analytical results.
    Type of Medium: Series available for loan
    Pages: 74 Seiten , Illustrationen
    Series Statement: CRREL Report 83-12
    Language: English
    Note: CONTENTS Abstract Preface Introduction Finite differences applied to heat transfer Heat conduction equation Boundary conditions Phase change Computer program ADDATA, the data subroutine TRIDIG, the matrix solver ISOTHM, the isotherm finider ADI, main program ADEPC, main program Verification of ADI Comparison of ADI with analytical results Comparison of ADI with experimental results Verification of ADIPC Comparison of ADIPC with analytical results-the Neumann solution Comparison of ADIPC with analytical results-two-dimensional phase change verification User instruction for ADI User instruction for ADIPC Conclusions Literature cited Appendix A. Program INFSUM and sample input and output for program ADI Appendix B. Program ADIPC and sample input and output
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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-201-85/10
    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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  • 51
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    Call number: ZSP-201-84/18
    In: CRREL Report, 84-18
    Description / Table of Contents: This report investigates the influences of turbulence and water temperature on frazil ice formation. The rate and thequantity of frazil ice formed in a specified volume of supercooled water increase with both increasing turbulence inten-sitv and decreasing water temperature. The influence of turbulence intensity on the rate of frazil ice formation, how-ever. is more pronounced for larger initial supercooling. The turbulence characteristics of a flow affect the rate offrazil ice formation by governing the temperature to which the flow can be supercooled, by influencing heat transferfrom the frazil ice to surrounding water, and by promoting collision nucleation, particle and floc rupture and increasingthe number of nucleation sites. larger frazil ice particles formed in water supercooled to lower temperatures. The par-ticles usually were disks, with diameters several orders greater than their thickness. Particle size generally decreased with increasing turbulence intensity. This report develops an analytical model, in which the rate of frazil ice formation isrelated to temperature rise of a turbulent volume of water from the release of latent heat of fusion of liquid water toice. Experiments conducted in a turbulence jar with a heated, vertically oscillating grid served both to guide and tocalibrate thanalytical'model as well as to afford insights into frazil ice formation. The formation of frazil ice wasstudied for Vemperatures of supercooled water ranging from -0.9° to -0.050°C.
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    Pages: vi, 50 Seiten , Illustrationen
    Series Statement: CRREL Report 84-18
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Background Scope of study Literature review Introduction Incipient formation of frazil ice Particle size and evolution of frazil ice Influences of turbulence and water temperature on the rate of frazil ice formation Conclusions Analytical model Introduction Elements of heat transfer Elements of turbulence Experimentation Experimental apparatus Experimental procedure Results Introduction Nucleation of frazil ice Influences of turbulence on frazil ice formation Water temperature Influences of water temperature and turbulence on the concentration of frazil ice Frazil ice particle shape and size Conclusions Literature cited Appendix A: Preliminary frazil ice experiments Flume experiments Couette-flow Appendix B: Listing of computer program for calculation of frazil ice formation Appendix C: Water temperature rise attributable to frazil ice formation as computed usingthe analytical model .
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  • 52
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-84/12
    In: CRREL Report, 84-12
    Description / Table of Contents: Icing on stationary structures such as oil rigs is becoming an increasingly serious problem as offshore drilling operations in the subpolar regions become more common. Little information exists on this subject. Extensive observations have been made of icing on the upper structures of moving ships, but the complexity of this problem makes analysis of the results very difficult. Even the generation of water drops in this case involves many factors, such as windspeed, wave direction relative to the bearing of the ship, and size and free-board of the ship. On stationary structures, however, the problem is much simpler, since the major factor in drop generation is whitecaps produced by wind, and no motion of the structure is involved. In the present study, a theoretical calculation was made by combining the data available on the generation of drops by wind with data on the proportion of ice frozen from the collected water. The rate of ice accumulation on stationary structures was calculated using published data. The results were compared with icing measured on board ships. Although the general trend of this calculation indicated parallelism with the onboard measurements, the measured ice accumulation rate on ships needed a 5 to 8 m/s higher windspeed to correspond with the calculated rate for stationary structures.
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    Pages: ii, 13 Seiten , Illustrationen
    Series Statement: CRREL Report 84-12
    Language: English
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  • 53
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    Call number: ZSP-201-84/15
    In: CRREL Report, 84-15
    Description / Table of Contents: Measurements of meltwater pH from annual layers of South Pole firn and ice samples ranging in age from 40 to 2000 years B.P. show that precipitation at this remote site has a higher natural acidity than that expected from atmospheric equilibrium with CO2. The average pH of deaerated (CO2-free) samples was 5.64 + or - 0.08, while air-equilibrated samples averaged 5.37 + or - 0.008, a pH that is about a factor of two more acidic than the expected background pH of 5.65. The observed 'excess' acidity can be accounted for by natural SO4(2)- and NO(3)- levels in the samples probably originating from non-anthropogenic H2SO4 and HNO3. Because of the presence of these naturally occurring acids in South Pole precipitation, a pH of 5.4 is considered a more representative baseline reference pH for acid precipitation studies.
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    Pages: ii, 12 Seiten , Illustrationen
    Series Statement: CRREL Report 84-15
    Language: English
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  • 54
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-86/2
    In: CRREL Report, 86-2
    Description / Table of Contents: The behavior of reinforced and unreinforced concrete beams was studied under impact loading at low temperatures, and the results were compared to the behavior of reinforcing steel (rebar) in Charpy-V impact tests. Transition temperatures as low as -30°C were obtained for the rebars in the Charpy-V tests whereas no brittle failures occured in the rebars in the reinforced concrete beams at the temperature as low as -63°C, even in beams whe're the rebars were Intentionally notched. The impact strength of unreinforced concrete increases considerably at lower temperatures, thus reducing cracking of reinforcedconcrete structures and significantly increasing the safety of lightly reinforced structures.
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    Pages: iii, 25 Seiten , Illustrationen
    Series Statement: CRREL Report 86-2
    Language: English
    Note: Abstract Preface Introduction Tests Test specimens Test methods Results Impact strength of beanms Ductility of beams Effect of notched bars Elastic deflection of beams Impact tests on rebars Conclusions and summary Literature cited Appendix A: Beam crack patterns Appendix B: Photomicrographs of failure surfaces of some steels
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  • 55
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    Call number: ZSP-201-86/8
    In: CRREL Report, 86-8
    Description / Table of Contents: In this work, numerical computations of heat transfer for freezing a shaft wall have been conducted. Both fixed mesh and deforming mesh finite-element methods are used. In the fixed mesh method, latent heat effects are accounted for through a δ function in the apparent heat capacity. In the deforming mesh method, an automatic mesh-generation technique with transfinite mappings is used, and in this method two different approaches are taken to evaluate the movement of the interface. The freeze-pipes are considered as point sources with irregular distribution. The advancement of the inner and outer boundaries of the frozen wall is found to be in agreement with the previously computed results
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    Pages: iii, 31 Seiten , Illustrationen
    Series Statement: CRREL Report 86-8
    Language: English
    Note: CONTENTS Abstract Preface Introduction Basic finite-element formulas Description of problem Finite-element equation-fixed mesh Finite-element equation-deforming mesh Transfinite mapping technique Computations and conclusions Literature cited Appendix A : Point heat sources Appendix B: Evaluation of the integral including latent heat (fixed mesh) Appendix C: Specification of [K] -deforming mesh Appendix D: Specifying δΤ/δn and the direction of mj for method I Appendix E: Procedures of method 2 Appendix F: Explanation of programs
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  • 56
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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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  • 57
    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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  • 58
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    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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  • 59
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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.
    Type of Medium: Series available for loan
    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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  • 60
    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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  • 61
    Call number: ZSP-201-87/3
    In: CRREL Report, 87-3
    Description / Table of Contents: This report describes the structural analysis of multi-year sea ice samples that were tested in the first phase of a program designed to obtain a comprehensive understanding of the mechanical properties of multi-year sea ice from the Alaskan Beaufort Sea. Each test specimen is classified into one of three major ice texture categories: granular, columnar, or a mixture of columnar and granular ice. The crystallographic orientation, percent columnar ice, and grain size are then evaluated for the granular and/or columnar ice in the sample. Test results are interpreted with respect to these parameters. The overall composition of multi-year ridges is also considered, based on the extensive field sampling that was done in the program
    Type of Medium: Series available for loan
    Pages: iii, 40 Seiten , Illustrationen
    Series Statement: CRREL Report 87-3
    Language: English
    Note: CONTENTS Abstract Preface Introduction Sample analysis Continuous multi-year ridge core Tested multi-year ridge ice samples Tested multi-year floe ice samples Ice description Uniaxial constant-strain-rate compression tests Uniaxial constant-load compression tests Uniaxial constant-strain-rate tension tests Triaxial constant-strain-rate compression test Conclusions Literature cited Appendix A: Multi-year ridge sample data Appendix B: Multi-year floe sample data
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  • 62
    Call number: ZSP-201-82/15
    In: CRREL Report, 82-15
    Description / Table of Contents: An experiment is described that demonstrates the balance between the ice and the unfrozen water in a frozen soil as water is removed. Nuclear magnetic resonance (NMR) is used to monitor the unfrozen water content as the soil is dehydrated by a molecular sieve material. Our results show that the unfrozen water content of a Morin clay soil remains constant until the total water content has been reduced to the point where no ice remains in the system. Once the ice is depleted, the unfrozen water content determined by NMR corresponds to the total water content of the soil determined by the weight of water removed by the molecular sieve material. Thus the validity of utilizing NMR in determining unfrozen water contents vs temperature is established.
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    Pages: 8 Seiten , Illustrationen
    Series Statement: CRREL Report 82-15
    Language: English
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  • 63
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-87/20
    In: CRREL Report, 87-20
    Description / Table of Contents: The structure and salinity characteristics of saline ice slabs removed from ice sheets grown in an outdoor pool have been studied and related to the complex relative dielectric permittivity measured with free-space transmission techniques at 4.80 and 9.50 GHz. The saline ice closely simulated arctic sea ice in its structural and salinity characteristics, which were regularly monitored in a number of ice sheets grown during the winters of 1983-84 and 1984-85. In-situ transmission measurements at similar frequencies were also made on the ice sheets themselves using antennas located above and beneath the ice. The slab measurements were made during warming from -29° to -2°C on slabs grown during the winter of 1983-84 (4.75 GHz) and during a warming and cooling cycle over a slightly larger temperature range on slabs grown during the winter of 1984-85 (4.80 and 9.50 GHz).
    Type of Medium: Series available for loan
    Pages: v, 41 Seiten , Illustrationen
    Series Statement: CRREL Report 87-20
    Language: English
    Note: CONTENTS Abstract Preface Part I - Structural properties Introduction Experimental setup Analytical techniques Results and discussion 1983-84 experiments 1984-85 experiments Conclusions and recommendations Part Il - Microwave properties Introduction Measurement techniques Results 1983-84 experiments 1984-85 experiments 1984-85 in-situ experiments Discussion Comparison of data Analytical modeling Summary and conclusions Literature cited Appendix A: Dielectric mixing model of sea ice
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  • 64
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-87/21
    In: CRREL Report, 87-21
    Description / Table of Contents: The author measured time series of longitudinal (u) and vertical (w) velocity and temperature (t) and humidity (q) fluctuations with fast-responding sensors in the near-neutrally stable surface layer over a snow-covered field. These series yielded individual spectra and u-w, w-t, w-q and t-q cospectra, phase spectra and coherence spectra for nondimensional frequencies (fz/U) from roughly 0.001 to 10. With the exception of the u-w cospectra, all the spectra and cospectra displayed the expected dependence on frequency in an inertial or inertial-convective subrange. All, however, contained significantly more energy at low frequency than the Kansas neutral-stability spectra and cospectra. This excess low-frequency energy and the erratic behavior of the u-w cospectra imply that forested hills bordering the site on two sides were producing disturbances in the flow field at scales roughly equal to the height of the hills, 100 m. The phase and coherence spectra suggest that internal gravity waves were also frequently present, since the atmospheric boundary layer generally had slightly stable stratification. Consequently, at this complex site, turbulence alone determines the spectra and cospectra at high frequency; at low frequency the spectra and cospectra reflect a combination of topographically generated turbulence and internal waves. From the measured temperature and humidity spectra and the t-q cospectra, the author computed refractive index spectra for light of 0.55-micrometer and millimeter wavelengths. The refractive index spectra had shapes like the other scalar spectra: excess energy at low frequency and an inertial-convective subrange at high frequency.
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    Pages: v, 50 Seiten , Illustrationen
    Series Statement: CRREL Report 87-21
    Language: English
    Note: CONTENTS Abstract Preface Introduction Measurements Spectra u and w velocity spectra Temperature and humidity spectra Inertial-dissipation estimates Cospectra u-w cospectra w-t and w-q cospectra t-q cospectra Refractive index spectra Conclusions Literature cited
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  • 65
    Call number: ZSP-201-88/1
    In: CRREL Report, 88-1
    Description / Table of Contents: The Cornish-Windsor bridge is the longest covered bridge in the United States and has significant historical value. At a large peak flow, dynamic ice breakup of the Connecticut River can threaten the bridge and cause flood damage in the town of Windsor, Vermont. Throughout the 1985-86 winter we regularly monitored ice conditions, including a midwinter dynamic ice breakup on 27 January. We conducted controlled release tests over the operating range of the turbines at Wilder Dam upstream during both open water and ice cover conditions. These data and observations were analyzed in light of more than 60 years of temperature and discharge records. Our analysis indicates that river regulation presents alternatives for ice management that would minimize the probability of bridge damage and flooding during breakup. The flow can be regulated early in the winter to promote the growth of a stable ice cover, minimizing the total ice production in the reach. In the weeks prior to breakup, sustained releases and above-freezing air temperatures cause melting, weakening and gradual breakup of the ice, greatly reducing the flooding potential. Also, it is possible to produce a controlled ice breakup prior to an imminent natural event at lower stage and discharge. All of these ice control alternatives have associated power production costs.
    Type of Medium: Series available for loan
    Pages: iii, 21 Seiten , Illustrationen
    Series Statement: CRREL Report 88-1
    Language: English
    Note: CONTENTS Abstract Preface Introduction Background Analysis of historical data Field observations Controlled release tests January 1986 ice breakup Connecticut River ice control Minimizing ice production Hydrothermal melting Controlled ice breakup Conclusions Literature cited Appendix A: Detailed ice breakup chronology
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  • 66
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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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  • 67
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-88/15
    In: CRREL Report, 88-15
    Description / Table of Contents: The main points covered are: (1)modeling criteria for ships in ice, which must take into account the presence of a solid boundary at the water surface; (2) types of model ice used in various tanks-saline ice, urea-doped ice, EG/AD/S ice and synthetic ice; (3) techniques for growing model ice sheets, and achieving and monitoring the required ice properties; (4) limitations of both model ice and property measurement techniques; (5) model testing procedures for EHP and SHP tests and their limitations; (6) comparison between model test results and available full-scale trials data; (7) existing empirical and analytical or semi-analytical algorithms for predicting ship performance in level ice; (8) current research at CRREL and other research facilities to improve modeling techniques and data interpretation; and (9) novel bow designs for ice-transiting vessels.
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    Pages: v, 39 Seiten , Illustrationen
    Series Statement: CRREL Report 88-15
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction General considerations Ice properties Modulus, E Characteristic length, Ic Flexural strength, σf Com pressive strength, σc Shear strength, σs Poisson's ratio, ϑ Fracture toughness, Kic Density, ρi Ice-hull friction factor, fi Model ice Synthetic ice Columnar saline ice Columnar carbamide ice Fine-grained ice EG/AD/S model ice Model test procedures Ice growth and monitoring EHP tests SHP test Test data analysis--comparison with full scale Analysis of test results Comparison with full-scale data Analytical and empirical predictors Empirical predictors Analytical and semi-analytical schemes Current research efforts in ice modeling International cooperative research Ice testing CRREL research on ship-ice interaction Novel icebreaking bow designs Conclusions and final remarks Literature cited
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  • 68
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-88/13
    In: CRREL Report, 88-13
    Description / Table of Contents: In many sea ice engineering problems the ice sheet has been assumed to be a homogeneous plate whose mechanical properties are estimated from the bulk salinity and average temperature of the ice sheet. Typically no regard has been given to the vertical variation of ice properties in the ice sheet or to the time of ice formation. This paper first reviews some of the mechanical properties of sea ice, including the ice tensile, flexural and shear strengths, as well as the ice modulus. Equations for these properties are given as functions of the ice brine volume, which can be determined from the ice salinity and temperature. Next a numerical, finite difference model is developed to predict the salinity and temperature profiles of a growing ice sheet. In this model ice temperatures are calculated by performing an energy balance of the heat fluxes at the ice surface. The conductive heat flux is used to calculate the rate of ice growth and ice thickness by applying the Stefan ice growth equation. Ice salinities are determined by considering the amount of initial salt entrapment at the ice/water interface and the subsequent brine drainage due to brine expulsion and gravity drainage. Ice salinity and temperature profiles are generated using climatological data for the Central Arctic basin. The predicted salinity and temperature profiles are combined with the mechanical property data to provide mechanical property profiles for first-year sea ice of different thicknesses, grown at different times of the winter. The predicted profiles give composite plate properties that are significantly different from bulk properties obtained by assuming homogeneous plates. In addition the failure strength profiles give maximum strength in the interior of the sheet as contrasted with the usual assumption of maximum strength at the cold, upper ice surface. Surprisingly the mechanical property profiles are only a function of the ice thickness, independent of the time of ice formation.
    Type of Medium: Series available for loan
    Pages: v, 63 Seiten , Illustrationen
    Series Statement: CRREL Report 88-13
    Language: English
    Note: CONTENTS Abstract Preface Introduction Structure Composition Mechanical properties Strength Elastic constants The temperature-salinity model Temperature profiles Salinity profiles Composite plate properties Results Conclusions Literature cited Appendix A: Details of the equations for ice surface temperature and conductive heat flux Appendix B: Calculated profile and bulk properties of an ice sheet of varying thickness Appendix C: Calculated profile and bulk properties of 30- and 91-cm-thick ice sheets
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  • 69
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    Call number: ZSP-201-88/18
    In: CRREL Report, 88-18
    Description / Table of Contents: The results of a laboratory testing program, carried out to compare two independent methods for determining the unfrozen water content of soils, are described. With the time domain reflectometry method, the unfrozen water content is inferred from a calibration curve of apparent dielectric constant vs volumetric water content, determined by experiment. Previously, precise calibration of the TDR technique was hindered by the lack of a reference comparison method, which nuclear magnetic resonance now offers. This has provided a much greater scope for calibration, including a wide range of soil types and temperature (unfrozen water content). The results of the testing program yielded a relationship between dielectric constant and volumetric unfrozen water content that is largely unaffected by soil type, although a subtle but apparent dependency on the texture of the soil was noted. It is suggested that this effect originates from the lower valued dielectric constant for absorbed soil water. In spite of this, the general equation presented may be considered adequate for most practical purposes. The standard error of estimate is 0.015 cc/cc, although this may be reduced by calibrating for individual soils. Brief guidelines on system and probe design are offered to help ensure that use of the TDR method will give results consistent with the relationship presented.
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    Pages: ii, 16 Seiten , Illustrationen
    Series Statement: CRREL Report 88-18
    Language: English
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  • 70
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    Call number: ZSP-201-88/20
    In: CRREL Report, 88-20
    Description / Table of Contents: This study develops design criteria for a new sludge dewatering unit operation called a sludge freezing bed. This bed uses natural freeze-thaw to condition the sludge. The total depth of sludge that can be frozen, thawed and dewatered by this process in a year is the main criterion needed for design. Laboratory tests assessed the dewaterability of freeze-thaw conditioned water treatment plant sludge and both anaerobically and aerobically digested wastewater sludges at various depths. Mathematical models for predicting the design depth were developed; values for the input parameters to the models were obtained from the literature or from laboratory and pilot-scale experiments. The dewaterability tests indicated that the depth of sludge that can be applied is not limited by drainability. Up to 2.0 m of each sludge drained in minutes after freeze-thaw conditioning. Except for the aerobically digested sludge, the solids content after drainage is high enough to permit mechanical removal. The physical and thermal characteristics of frozen sludge were found to be equivalent to those of ice. An analysis of the freezing and thawing models reveals that the design of a freezing bed will depend on the duration and intensity of the freezing and thawing seasons.
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    Pages: v, 58 Seiten , Illustrationen
    Series Statement: CRREL Report 88-20
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Background Purpose Scope Literature review Fundamentals of freeze separation Applications of freeze separation technology Conclusions Concept development Background Site visits Final concept Dewaterability studies Sludge characteristics Specific resistance and capillary suction time Filtrate quality Drainage tests Drying tests Development of design models Basic energy balance relationship Development of freezing model Development of thawing model Other models Evaluation of sludge input parameters Frozen sludge density, ϱf Layer thickness, ϵ Settled solids fraction, θ Thermal conductivities, Kfs, Kss Latent heat of fusion, L Absorptance, α Freezing point, Tf Summary Evaluation of climatic input parameters Ambient air temperatures, Taf, Tat Insolation, I Convection coefficient, hc Use of models for design Freezing design depth Thawing design depth Validation Example Conclusions anid recommendations Literature cited Appendix A: Sludge freezing at the Salem, New Hampshire, Wastewater Treatment Plant
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  • 71
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-89/14
    In: CRREL Report, 89-14
    Description / Table of Contents: The effects of runner material and surface conditions on the friction between runners and ice were studied. A model sled was pushed over a 6-m-long ice sheet and the reduction of speed of the sliding sled was measured. The friction calculated by the reduction of speed between two gates indicated that smooth runners showed lower friction at around -1°C than at around -10°C, as expected, but the friction of rough runners showed little temperature dependence. The lower thermally conductive runners showed lower friction than higher thermally conductive smooth runners as the theory predicted, but such effects were obscured on rougher runners.
    Type of Medium: Series available for loan
    Pages: iii, 23 Seiten , Illustrationen
    Series Statement: CRREL Report 89-14
    Language: English
    Note: CONTENTS Preface Introduction Apparatus and procedures General approach Sled design Sled propulsion Ice sheet preparation Experimental procedure Results General remarks Effect of runner temperature Effect of runner surface Effect of ice surface conditions Effect of velocity Effect of runner materials Observations of replicate surfaces Statistical analysis Discussion Molecular interactions Mechanical deformations Thermal energy dissipation Hydrodynamidc processes Comparison of energy loss mechanisms Summary and conclusions Literature cited
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  • 72
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-88/14
    In: CRREL Report, 88-14
    Description / Table of Contents: An experimental study covering a mass flow rate ranging from 1.62 to 67.45 g/cm2-s and snow density varying from 0.377 to 0.472 g/cm3 has been conducted. Pressure drops ranging from 0.012 to 2.868 gf/cm2 were recorded. A plot of the friction factor fp vs Rep (defined as the classical Reynolds number Re for fluid flow through conduits) showed a good representation of all the experimental data. The least-squares analysis resulted in an expression of f sub p = 118/Rep to the 1.095 power for snow, in comparison with the expression f sub p = 64/Rep developed for fluid flow through porous media of randomly packed metallic and nonmetallic materials of spherical and nonspherical shapes.
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    Pages: iv, 18 Seiten , Illustrationen
    Series Statement: CRREL Report 88-14
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Experimental setup and procedure Experimental results Discussion and conclusions Literature cited
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  • 73
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-89/2
    In: CRREL Report, 89-2
    Description / Table of Contents: A brash ice jam in the South Channel of the St. Clair River was profiled in February 1987 using a helicopter-borne short-pulse radar operating in the UHF band near 500 MHz. During the same time, measurements of the brash ice depth and water temperature were made from a Coast Guard icebreaker. The returned radar pulses consisted of a strong coherent reflection from the water surface, preceded (and followed) by incoherent returns from the brash ice. The measured waveform time delays were then converted to mean freeboard height of the brash ice pieces above the water surface. Given the mean freeboard height, an estimate of the total brash ice thickness was made. This estimate was greater than the range of the direct shipboard measurements. The difference is believed due to differences between ice porosity above and below the water line, to melting within the ice and to partial submergence of some of the surface pieces. It is concluded that this technique could be used for mapping relative brash ice depth if the complexities of automating waveform analysis could be overcome.
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    Pages: iv, 25 Seiten , Illustrationen
    Series Statement: CRREL Report 89-2
    Language: English
    Note: CONTENTS Abstract Preface Introduction Objectives and procedures Equipment Radar Brash ice probe Temperature measurements St. Clair River ice conditions Results and discussion Thickness and temperature Size distribution Radar survey Discussion of errors Porosity Phase state of the ice Partial submergence of individual pieces Spectra of reflected energy Conclusions and recommendations Literature cited Appendix A: Laboratory verification of surface scattering from a simulated ice jam Appendix B: Display of digitized and processed data
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  • 74
    Call number: ZSP-201-89/10
    In: CRREL Report, 89-10
    Description / Table of Contents: In early fall 1984, a questionnaire was sent to over 325 general aviation airports in cold regions. The results from over 200 responses were compiled and evaluated and over 20 airport managers were contacted for additional details. Site visits were made to 36 airports to obtain additional information. The most common pavement problems identified in the study were associated with non-traffic-related phenomena and include 1) pre-existing cracks reflecting through asphalt concrete overlays (in two years less), 2) thermal cracking, and 3) longitudinal cracking (at a construction joint). Most of the airports experienced 1) water pumping up through cracks and joints in the pavements during spring thaw, or 2) additional roughness due to differential frost heave in the winter, or both problems. Many airport managers reported that debris was generated at cracks during the winter and spring. Many pavement problems can be traced to the evolutionary history of general aviation airports and the lack of consideration for site drainage. Based on the recognition of these problems, several future research programs are identified.
    Type of Medium: Series available for loan
    Pages: v, 147 Seiten , Illustrationen
    Series Statement: CRREL Report 89-10
    Language: English
    Note: CONTENTS Abstract Preface Introduction Statement of the problem Purpose and scope Background - the physical environment and airport pavements Physical environment of study area Comparison of highway and general aviation airport pavements Types of pavements and surface treatments Pavement distress and condition rating Surveys of airport pavement distress Airport pavement performance problems in cold regions Cracking Distortion and pavement faulting Disintegration Inadequate skid resistance Improper maintenance Stripping Statement of research needs Basis for statement of research needs Performance of overlays Recycling/reconstructing airport pavements Drainage of airport pavement structures Eliminating/accommodating differential frost heave Evaluation of adequacy of design procedures Maintenance products and performance Control of transverse cracking Additives for asphalt concrete Performance documentation Wildlife conservation vs aircraft safety Literature cited Appendix A: Questionnaire and listing of airports contacted Appendix B: Summary listing of questionnaire responses Appendix C: Narrative summary of site visits
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  • 75
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-89/21
    In: CRREL Report, 89-21
    Description / Table of Contents: The physical characteristics of blue ice ablation areas in Antarctica are described and some representative ablation rates are given. The possibilities for using blue-ice areas as airfields are outlined and exploratory surveys are mentioned. Site details are given for icefields at Mount Howe, Mill Glacier, Patriot Hills, Rosser Ridge, Mount Lechner, S1 near Casey station, and on the Ross Ice Shelf near McMurdo station. The surface roughness of blue ice is discussed, microrelief surveys are presented for Mount Howe and Patriot Hills, and spectral analyses are used to develop relations between bump height and wavelength. U.S. military specifications for the roughness limits of various types of runways are summarized and graphical comparisons are made with the roughness analyses for Mount Howe and Patriot Hills. Special machines for smoothing ice runways are discussed and design specifications are developed. Some notes on ground facilities and ground transport are included. Appendices give discussions of weather patterns in the Transantarctic Mountains and methodology for making spectral analyses of surface roughness. It is concluded that glacier-ice airfields for conventional transport aircraft can be developed at low cost in Antarctica. Recommendations for further work are offered.
    Type of Medium: Series available for loan
    Pages: v, 105 Seiten , Illustrationen
    Series Statement: CRREL Report 89-21
    Language: English
    Note: CONTENTS Abstract Preface Introduction Blue-ice areas Blue-ice areas as airfield sites The formation of blue-ice areas Ablation rates at blue-ice areas Exploratory surveys at blue-ice areas Mount Howe Mill Glacier / Plunket Point Patriot Hills Rosser Ridge Mount Lechner The S-1 site near Casey station The McMurdo "Pegasus Site" Surface roughness of blue ice Analysis and characterization of surface roughness Surface preparation to reduce ice roughness Ground facilities Ground transport Conclusions and recommendations Literature cited and selected references Appendix A: Survey data for Patriot Hills, Mount Howe and Mill Glacier Appendix B: Analysis of surface roughness at blue-ice sites Appendix C: Meteorological conditions to be expected in summer in the Trans-antarctic Mountains
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  • 76
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-80/9
    In: CRREL Report, 80-9
    Description / Table of Contents: Explosive cratering tests were conducted in seasonally frozen and thawed gravel at Ft. Richardson near Anchorage, Alaska, and in seasonallly frozen and thawed silt overlying permafrost and in silt permafrost at Ft. Wainwright near Fairbanks, Alaska. Explosive charge weights ranged from 26 to 3120 lb and charge burial depths ranged from about 3 to 40 ft. The cube root of the charge weight scaling was used to determine maximum scaled crater dimensions and optimum scaled depth of burial of the charge. Test results for frozen and thawed gravel were essentially the same because of the low moisture content and the relatively shallow depth of freezing (5 to 6 ft). The optimum depth of burial of the charge for maximizing the apparent radius and depth and the true radius was about 1.8 times the cube root of the charge weight for both the frozen and thawed conditions. In seasonally frozen silt overlying a talik and silt permafrost the maximum scaled crater dimensions and optimum scaled burial depths of the charge were smaller than for the thawed condition except for the true crater dimensions. The channeling of energy in the talik produces maximum crater dimensions and an optimum burial depth for the true crater that is larger than for the thawed condition. The results for the homogeneous silt permafrost were very similar to the frozen gravel results with much smaller maximum crater dimensions and smaller optimum charge burial depths than for the thawed silt overlying permafrost.
    Type of Medium: Series available for loan
    Pages: v, 21 Seiten , Illustrationen
    Series Statement: CRREL Report 80-9
    Language: English
    Note: CONTENTS Abstract Preface Metric conversion table Introduction Test sites Test procedures and materials Analysis of test data Mobility tests Conclusions Literature cited
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  • 77
    Call number: ZSP-201-80/19
    In: CRREL Report, 80-19
    Description / Table of Contents: During the period 1975-1978 the Federal Highway Administration sponsored a series of environmental engineering in­vestigations along the Yukon River to Prudhoe Bay Haul Road. In 1976 the Department of Energy joined these in­vestigations with a series of ecological projects which continue to the present. Both agencies research efforts were con­ducted on a cooperative basis with CRREL’s in-house research program. The objectives of the research focused on 1) an evaluation of the performance of the road, 2) an assessment of changes in the environment associated with the road, 3) documentation of flora and vegetation along the 577-km-long transect, 4) methodologies for revegetation and restoration, and 5) an assessment of biological parameters as indicators of environmental integrity. In support of these objectives, specific studies were undertaken that investigated the climate along the road, thaw and subsidence beneath and adjacent to the road, drainage and side slope performance, distribution and properties of road dust, vegetation distribution, vegetation disturbance and recovery, occurrence of weeds and weedy species, erosion and its control, revegetation and restoration, and construction of the fuel gas line. This report presents background, information on the region, detailed results of the road thaw subsidence and dust investigations, and summaries of revegetation, fuel gas line, vegetation distribution, soil, and weed studies.
    Type of Medium: Series available for loan
    Pages: xv, 187 Seiten , Illustrationen
    Series Statement: CRREL Report 80-19
    Language: English
    Note: CONTENTS Abstract Preface Summary Introduction Chapter 1. The road and its environment Introduction General physiography Regional climate Surficial and bedrock geology Permafrost and ground ice General biota Vegetation Floristic survey Vegetation mapping Soils and mapping Chapter 2. Roadbed performance and associated investigations Roadbed investigations Roadbed performance Performance of drainage features Performance of sideslopes Conclusions from road, drainage and sideslope performance studies Fuel gas line construction Chapter 3. Distribution and properties of road dust along the northern portion of the Haul Road Introduction Methods Results of wind direction and velocity measurements Dust load and distribution Particle size analyses of dust Chemical composition properties of dust and related samples Soil cation composition Dust impacts on vegetation Discussion and conclusions Chapter 4. Revegetation and restoration investigations Introduction Revegetation approaches Alyeska erosion control and revegetation program Weeds and weedy plants Performance of revegetation Alyeska willow cutting program CRREL restoration experiments Conclusions Revegetation recommendations General report recommendations Literature cited Appendix A: General environmental guidelines applicable to subarctic and arctic road construction Appendix B: University-based studies along the Yukon River-Prudhoe Bay Haul Road Appendix C: CRREL maps of Haul Road showing locations of all study Sites Appendix D: Additional Haul Road cross-sectional profiles Appendix E: Clay mineralogy of road-related materials Appendix F: List of reports in the Joint State/Federal Fish and Wildlife Ad­visory Team series
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  • 78
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-80/13
    In: CRREL Report, 80-13
    Description / Table of Contents: Specimens prepared from various types of ice without introducing excessive defects were tested at temperatures ranging from -2° to -190°C. These tests indicated slightly higher Charpy values at lower temperatures and in more highly dispersed material concentrations. Three modes of fracture occurred during testing. Depending on the temperature and the material composition, either of the first two modes, normal fracture or multiple fracture, will appear and will show a normal frequency distribution of Charpy values in each type of ice. The third mode, fracture from both ends,which frequently occurred in the NH4F doped ice, gave Charpy values two to five times higher than the mean value for normal fracture. It can, therefore, be concluded that certain types of doping can alter the mode of fracture, through which drastic modifications of impact resistance my be possible.
    Type of Medium: Series available for loan
    Pages: iii, 13 Seiten , Illustrationen
    Series Statement: CRREL Report 80-13
    Language: English
    Note: Contents Abstract Preface lntroduction Experimental Sample preparation Testing procedure Results General features Commercial Ice Notched commercial ice Sanded commercial ice Pure ice Single crystal ice Snow-ice Colloidal alumina-dispersed ice Colloidal silica.dispersed ice NH4F doped ice HF doped ice Discussion Literature cited
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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-201-80/16
    In: CRREL Report, 80-16
    Description / Table of Contents: Eight species of loricate choanoflagellates (Acanthoccidae), Acanthoecopsis spiculifera, Bicosta spinifera, Bicosta antennigera, Callicantha simplex, Calliacantha multispina aff., Crinolina aperta, Diaphanoeca multionnulata, and Parvicorbicula socialis, were observed in samples obtained from the Weddell Sea during the austral summer, 1977. D. multiannulata was described for the first time from these samples; the other organisms have either been described previously or are being described at this time. The distribution of most species within the Weddell Sea was widespread. The distributional, environmental, and morphological range of A. spiculifera, B. spinifera, C. aperta, and P. socialis was expanded. Habitats in which choanoflagellates were found included the water column, the edges of ice floes, ponds on ice floes, and the interiors of ice floes. The presence of choanoflagellates within the ice indicates that there may be a closely coupled trophic relationship with the other two biological components of the ice community, the ice algae and the bacteria. The presence in the ice of seven species with both a caudal appendage and anterior projections suggests a positive relationship between this lorica configuration and the ice habitat. Mechanisms of variance of transverse costal diameters between genera may be useful to the taxonomy and phylogeny of this family.
    Type of Medium: Series available for loan
    Pages: vi, 26 Seiten , Illustrationen
    Series Statement: CRREL Report 80-16
    Language: English
    Note: CONTENTS Introduction Literature review Objectives Materials and methods Results Observations Distribution and environmental tolerances Discussion Morphology Distribution Habitat Summary Conclusions Recommendations for future work Literature cited Appendix A Type descriptions of Acanthoecidae collected from the Weddell Sea
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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-201-80/17
    In: CRREL Report, 80-17
    Description / Table of Contents: Construction pads made of snow were used to build two sections of the Trans Alaska Pipeline and a small gas pipeline during the winter of 1975-76. Construction during the winter has become increasingly common in the Arctic. Surface travel and the use of heavy construction equipment on the unprotected tundra have been severely restricted, even during the winter, so the use of temporary winter roads and construction pads built of snow and ice has been advocated and is being adopted. The three snow construction pads mentioned above were the first snow roads and construction pads used on a large scale in Alaska. Snow roads and construction pads have two objectives: to protect the underlying vegetation and upper layers of the ground, and to provide a hard, smooth surface for travel and the operation of equipment. Several types have been built, and a brief discussion is given of their history and classification systems. The three snow construction pads used in construction of the Trans-Alaska Pipeline and the small gas pipeline in 1975-76 were visited and observed while in use. The Globe Creek snow pad, about 50 miles north of Fairbanks, was built primarily of manufactured snow hauled to the site and watered. With very high densities this pad withstood heavy traffic and use by heavy construction equipment except on one steep slope. There, the use of tracked vehicles and vehicles without front wheel drive disaggregated the snow on and near the surface so that vehicles without front wheel drive were unable to climb the hill. The Toolik snow pad, just north of the Brooks Range, was built of compacted snow and proved capable of supporting the heaviest traffic and construction equipment. The fuel gasline snow pad ran from the northern Brooks Range to the Arctic Coast and also proved capable of supporting the necessary traffic. Both the Toolik snow pad and the fuel gasline snow pad failed in very early May because of unseasonably warm and clear weather before the associated construction projects were completed. However, the three snow pads must be considered successful. Common problems were the lack of snow, slopes, unseasonably warm spring weather, and inexperience on the part of contractors and construction personnel.
    Type of Medium: Series available for loan
    Pages: v, 28 Seiten , Illustrationen
    Series Statement: CRREL Report 80-17
    Language: English
    Note: CONTENTS Abstract Preface Introduction History of snow and ice roads Classification of snow and ice roads Snow pads used by Alyeska during the winter of 1975-1976 The Globe Creek snow pad The Toolik snow pad The gasline snow pad Summary and conclusions Literature cited
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  • 81
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-80/11
    In: CRREL Report, 80-11
    Description / Table of Contents: Four types of roof leaks occurred at a new school building in Chevak, Alaska: 1) blowing snow entered the roof through eave vents and then melted, 2) slush and ice in roof valleys caused meltwater to overflow the valley flash­ing and run into the building, 3) water entered at a roof/wall intersection and 4) in many areas water entered through gaps in the sloping plywood deck. Sealing the eave vents made it impossible for blowing snow to enter the roof at the eaves. Electric heat tapes eliminated the valley icing problem. Missing flashing was responsible for the roof/wall intersection leaks. The absence of a vapor barrier in the roof was the cause of many leaks. We recom­mended that the roof be repaired from the exterior by removing component elements down to the plywood deck,installing an adhered continuous vapor barrier and reassembling the roof. An alternative roof cladding of compos­ition shingles was discussed as was conversion to a “cold roof.” The roof was repaired and modified following our recommendations, and problems appear to have been solved.
    Type of Medium: Series available for loan
    Pages: iv, 12 Seiten , Illustrationen
    Series Statement: CRREL Report 80-11
    Language: English
    Note: CONTENTS Abstract Preface Conversion factors Introduction Description of school Roof problems Snow infiltration leaks Valley leaks Intersection leaks Condensation leaks Tests to verify the cause of condensation leaks Eliminating the condensation leaks Recommendations for eliminating condensation leaks Repairing existing roof An alternative roof cladding The "cold roof" alternative Repairs and modifications Summary and conclusions
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  • 82
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    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-81/16
    In: CRREL Report, 81-16
    Description / Table of Contents: An air-transportable shelter designed and built at CRREL for use in cold regions underwent testing in Hanover, New Hampshire, and Ft. Greely, Alaska. The shelter demonstrated some of its capabilities for mobility by being towed for more than 60 miles behind various vehicles and by being transported on a C-130 cargo airplane, a CH-47 helicopter, and a trailer truck. The shelter proved to be very easy for a crew of two to four to set up in all weather conditions including -40 F cold. However, the gasoline-powered generator, which was a source for space heat as well as electricity, functioned very poorly. Overall, the prototype successfully demonstrated qualities of self-reliance, ease of operation and thermal efficiency.
    Type of Medium: Series available for loan
    Pages: v, 20 Seiten , Illustrationen
    Series Statement: CRREL Report 81-16
    Language: English
    Note: CONTENTS Abstract Preface Metric conversion factors Summary Introduction Description of shelter Test procedures and results Mobility Ease of erecting and striking Therinal efficiency and performance Heat output Electrical system Habitation Safety features Water system Shelter reliability Structure Performance of other shelters Conclusions Future studies Literature cited
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  • 83
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    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-81/17
    In: CRREL Report, 81-17
    Description / Table of Contents: Environmental conditions are described for the continental shelf of the western Arctic, and for the shelf of Labrador and Newfoundland. Special emphasis is given to the gouging of bottom sediments by ice pressure ridges and icebergs, and an approach to systematic risk analysis is outlined. Protection os subsea pipelines and cables by trenching and direct embedment is discussed, touching on burial depth, degree of protection, and environmental impact. Conventional land techniques can be adapted for trenching across the beach and through the shallows, but in deeper water special equipment is required. The devices discussed include hydraulic dredges, submarine dredges, plows, rippers, water jets, disc saws and wheel ditchers, ladder trenchers and chain saws, routers and slot millers, ladder dredges, vibratory and percussive machines, and blasting systems. Consideration is given to the relative merits of working with seabed vehicles, or alternatively with direct surface support from vessels or from the sea ice
    Type of Medium: Series available for loan
    Pages: 38 Seiten , Illustrationen
    Series Statement: CRREL Report 81-17
    Language: English
    Note: CONTENTS Abstract Preface Introduction The western Arctic of North America The continental shelf of Newfoundland and Labrador Burial depth for pipes and cables Degree of protection offered by burial Environmental impact Trenching the beach and the shallows in the western Arctic Trenching beyond the shallows Suction, or hydraulic, dredging Bottom-t raveling cutterhead dredges Plows Rippers Water jets Subsea disc saws and wheel ditchers Subsea ladder trenchers and chain saws Subsea routers and slot millers Bucket ladder trenchers Vibratory and percussive devices Hard rock excavation under water Control and monitoring of subsea machines Vessels and vehicles Trenching from the sea ice Costs of subsea trenching Reference Appendix: Description of waters off Alaska and Newfoundland
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  • 84
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-81/9
    In: CRREL Report, 81-9
    Description / Table of Contents: Abstract: The calculation of the largest horizontal force a relatively thin floating ice plate may exert on a structure requires the knowledge of the buckling load for this floating plate. In the published literature on the stability of continuously supported beams and plates, it is usually assumed that this buckling force corresponds to the lowest bifurcation force Pcr. However, recent studies indicate that, generally, this is not the case, and this report clarifies the situation for floating ice plates. This problem is first studied on a simple model that exhibits the buckling mechanism of a floating ice plate but is amenable to an exact nonlinear analysis. This study shows that, depending on the ratio of the rigidities of the "liquid" and "plate," the post-buckling branch may rise or drop away from the bifurcation point. Thus, Pcr may or may not be the actual buckling load. It is also shown that when lift-off of "plate" from the "liquid" takes place the actual buckling load may drop substantially. This study is followed by an analysis of a floating compressed semi-infinite plate with a straight free edge, assuming that there is no lift-off. It is found that for this case there always exists a buckling load that is lower than Pcr. According to the obtained results, the value Pcr should be used with caution as a buckling load for floating ice plates. It is suggested that the buckling load be determined using the postbuckling equilibrium branch of the plate, taking into consideration the possibility of lift-off of the ice cover from the liquid base.
    Type of Medium: Series available for loan
    Pages: 7 Seiten , Illustrationen
    Series Statement: CRREL Report 81-9
    Language: English
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  • 85
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-81/10
    In: CRREL Report, 81-10
    Description / Table of Contents: Abstract: This treatise thoroughly reviews the subjects of density, thermal expansion and compressibility of ice; snow density change attributed to destructive, constructive and melt metamorphism; and the physics of regelation and the effects on penetration rate of both the thermal properties of the wire and stress level. Heat capacity, latent heat of fusion and thermal conductivity of ice and snow over a wide range of temperatures were analyzed with regression techniques. In the case of snow, the effect of density was also evaluated. The contribution of vapor diffusion to heat transfer through snow under both natural and forced convective conditions was assessed. Expressions representing specific and latent heat of sea ice in terms of sea ice salinity and temperature were given. Theoretical models were given that can predict the thermal conductivities of fresh bubbly ice and sea ice in terms of salinity, temperature and fractional air content.
    Type of Medium: Series available for loan
    Pages: 27 Seiten , Illustrationen
    Series Statement: CRREL Report 81-10
    Language: English
    Note: CONTENTS Abstract Preface Nomenclature Introduction Density, thermal expansion and compressibility of ice Density Thermal expansion Compressibility Density changes in snow Compaction Destructive metamorphism Constructive metamorphism Melt metamorphism Regelation Thermal properties of snow and fresh-water ice Heat capacity of snow and ice Latent heat Thermal conductivity of ice Thermal conductivity of snow Effective thermal diffusivity Heat transfer by water vapor diffusion in snow Heat and vapor transfer with forced convection Thermal properties of sea ice Specific heat of sea ice Heat of fusion of sea ice when 0° 〉 θ 〉 -8.2°C Density and thermal conductivity of sea ice Composition and air bubble content of sea ice above -8.2°C Thermal conductivity model for sea ice Thermal diffusivity of sea ice Method of determining thermal diffusivity Summary Literature cited
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  • 86
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-82/23
    In: CRREL Report, 82-23
    Description / Table of Contents: A direct filtration, water treatment pilot plant was operated on the Kenai River at Soldotna, Alaska, during the summer of 1980. The purpose of the pilot plant operations was to determine the feasibility of the direct filtration process for removal of glacial silt. The major criterion used to determine feasibility was production of water containing less than 1.0 NTU of turbidity. For the range of raw water turbidities encountered (22-34 NTU), the pilot plant testing indicated that direct filtration was feasible and could be considered as an alternative to conventional waiter treatment plants containing sedimentation tanks.
    Type of Medium: Series available for loan
    Pages: 26 Seiten , Illustrationen
    Series Statement: CRREL Report 82-23
    Language: English
    Note: CONTENTS Abstract Preface Conversion factors: U.S. customary to metric Introduction Glacial characteristics Water treatment Materials and methods Experimental design Pilot plant intake Hydrocyclone Chemical addition system Flocculation system Filtration system Pilot plant operations Coagulant chemical preparations Flow measurement Sampling Results and discussion Kenai River w ater quality Evaluation of pilot plant testing Performance of pilot plant elements Physical and chem ical variables Conclusions Recommendations Literature cited
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  • 87
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-82/24
    In: CRREL Report, 82-24
    Description / Table of Contents: Velocity data derived from petroleum industry seismic records from Harrison Bay show that high-velocity material ( or = 2 km/s) interpreted to be ice-bonded permafrost is common. In the eastern part of the bay, the depth to high velocity material increases and velocity decreases in an orderly manner with increasing distance from shore until the layer is no longer apparent. The western part of the bay is less orderly, possibly reflecting a different geological and thermal history. This western part may be an inundated section of the low coastal plain characterized by the region north of Teshekpuk Lake, and could have contained deep thaw lakes, creating low velocity zones. Along some seismic lines, the high-velocity material extends approximately 25 km offshore. Two anomalies have been found which could be associated with rapidly degrading permafrost. One is strong attenuation, which was interpreted as an indication of gas in the shallow deposits. The other is the presence of considerable seismic noise, including identifiable small seismic events. The origin of this noise has not been positively established, and it is proposed that it may indicate that some movement is occurring in the sediments due to thaw.
    Type of Medium: Series available for loan
    Pages: 65 Seiten , Illustrationen
    Series Statement: CRREL Report 82-24
    Language: English
    Note: CONTENTS Abstract Preface Introduction Methods Reading records Refractions Reflections Rayleigh waves Spatial resolution Anomalies Results and discussion Seismic velocity distribution Attenuation Low-level natural seismicity Summary Literature cited Appendix A: Error estimates Appendix B: Velocity profiles Appendix C: Seismic cross sections
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  • 88
    Call number: ZSP-201-82/26
    In: CRREL Report, 82-26
    Description / Table of Contents: The Caribou-Poker Creeks Research Watershed is a small (101.5-sq km) drainage basin located 48 km northwest of Fairbanks, Alaska. Elevations within the watershed range from 210 to 826 m, and approximately 28% of its area is underlain by permafrost. Climatic differences between the watershed and Fairbanks are primarily due to the higher elevation of the watershed. Generally the watershed climatic sites are warmer in winter and cooler in summer than Fairbanks. Within the watershed the greatest temperature contrasts exist in winter, when the valley-bottom sites are beneath the regional air temperature inversion, and the higher sites are above it. From May through September the total precipitation averages 270 mm, 1.47 times that received at Fairbanks. The annual precipitation is about 1.7 times that of Fairbanks. The historical precipitation record at Fairbanks indicates that summer precipitation was below the long-term normal in eight of the eleven years of watershed measurements (1969-1980); no climatic extremes occurred during this period. An analysis of annual streamflow data showed an inconsistency of baseflow recessions from year to year. The runoff-rainfall ratio for individual summer storms averaged 0.35 for Caribou Creek. Comparisons of spot discharge measurements of predominantly permafrost and non-permafrost subwatersheds showed that permafrost-dominated watersheds have a much flashier response to precipitation than non-permafrost watersheds. A comparison of the annual flow distribution of the watershed indicated that Caribou Creek has lower summer and higher winter discharges per unit area than the Chena or Salcha Rivers.
    Type of Medium: Series available for loan
    Pages: 42 Seiten , Illustrationen
    Series Statement: CRREL Report 82-26
    Language: English
    Note: CONTENTS Abstract Preface Introduction Setting Geology and soils Vegetation Climate Air temperature Precipitation Hydrology Annual and monthly runoff Individual storms Baseflow recessions Spatial flow variability Temporal flow variability Summary and conclusions Literature cited Appendix A: Station histories
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  • 89
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-82/27
    In: CRREL Report, 82-27
    Description / Table of Contents: Recommendations for economical thicknesses for building insulation result from a study of fuel and construction costs of 12 military installations in Alaska. A comparison between the insulation thickness that a building owner might choose today and what he might choose in 20 years indicates a trend for much thicker insulation in the future. An analysis of how much more expensive a building built today with the thickness that would be appropriate 20 years hence indicates only a small penalty in life-cycle costs for the additional insulation. Therefore, a minimum of R-32 walls and R-62 attics is recommended for most of Alaska.
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    Pages: 54 Seiten , Illustrationen
    Series Statement: CRREL Report 82-27
    Language: English
    Note: CONTENTS Abstract Preface Conversion factors Summary Introduction Determining economic thicknesses for insulation Background Analysis method for new construction Analysis method for reinsulating existing construction Sensitivity and longevity of the results Sensitivity Longevity Recommendations Saving money vs. saving energy Energy economics conservation Building energy performance standards Conclusion Literature cited Appendix A: Heating system costs Appendix B: Present worth factors Appendix C: Base case and incremental thermal properties Appendix D: LCC comparison graphs for wall and roof systems Appendix E: Cost penalties for energy conservatism Appendix F: Graphic aid for figuring energy savings thermal improvements
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  • 90
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    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-84/8
    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.
    Type of Medium: Series available for loan
    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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  • 91
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    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-82/34
    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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  • 92
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    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-82/42
    In: CRREL Report, 82-42
    Description / Table of Contents: A high-resolution impulse radar profiling system was evaluated for 1) detecting the existence of sea ice which coring has revealed to exist on the bottom of the Ross Ice Shelf at Site J-9, 2) detecting the preferred horizontal c-axis azi-muthal direction of the sea ice crystals, using the voltage amplitude of the radar reflection from the sea ice bottom, and 3) determining the direction of the currents under an Antarctic ice shelf. A field program was conducted consisting of a surface radar survey on the Ross Ice Shelf at Site J-9 and surface and airborne radar profiling on the McMurdo Ice Shelf. The CRREL impulse radar system, operating at a center frequency of either 80 MHz or 20 MHz, was unable to detect the shelf bottom at Site J-9, which drilling revealed to be 416 m below the snow surface. The radar system was used to profile the McMurdo Ice Shelf both from the snow surface and from the air; a shelf thickness of about 275 m was easily detected. Theoretical considerations indicate that the bulk conductivity of the ice shelf at Site J1-9 was higher than originally anticipated, and this limited the radar sounding depth to about 405 m when operating at a frequency of 20 MHz.
    Type of Medium: Series available for loan
    Pages: iv, 19 Seiten , Illustrationen
    Series Statement: CRREL Report 82-42
    Language: English
    Note: CONTENTS Abstract Introduction Profiling system Theoretical considerations Field program Discussion Literature cited
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  • 93
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-84/11
    In: CRREL Report, 84-11
    Description / Table of Contents: Data obtained from two sets of data buoys either air-dropped or deployed by ship onto the Weddell Sea pack ice during the period from Dec 1978 to Nov 1980 are presented. The buoy data include position, pressure and temperature information and to date represent the most complete combined weather and pack ice drift records for the ice-covered Southern Ocean regions. The buoys tended to drift north initially and then to turn east generally between latitudes 62°S and 64°S. Buoy 1433 turned east farther south at approximately 67°S but at about the same time as buoy 0527, implying that the westerly wind belt was farther south than usual in 1979. The range of air pressures-from about 950 mb to about 1020 mb is typical of the circumpolar low pressure trough in the Southern Hemisphere. All buoys were equipped with an internal or compartment temperature sensor. The 1980 buoys also contained an external air temperature sensor in a ventilated, shielded can at 1-m height. Although differences of 10°C or more between recorded air and compartment temperatures are common, the correlation between the two measured temperatures is generally very good. The compartment temperatures are higher probably because the buoy is radiationally heated. We found that subtracting 3°C from the average daily compartment temperature yielded a good estimate of the average air temperature for any given day. This technique can be used to construct average daily air temperature records for the 1979 buoys which only contained the internal or compartment temperature sensor.
    Type of Medium: Series available for loan
    Pages: v, 21 Seiten , Illustrationen
    Series Statement: CRREL Report 84-11
    Language: English
    Note: CONTENTS Abstract Preface Introduction Methods and instrumentation Results Drift tracks Pressure data Temperature data Discussion Conclusions Literature cited
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  • 94
    Call number: ZSP-201-84/9
    In: CRREL Report, 84-9
    Description / Table of Contents: This report presents the results of the first phase of a test program designed to obtain a comprehensive understanding of the mechanical properties of multi-year sea ice from the Alaskan Beaufort Sea. In Phase I, 222 constant-strain-rate uni-axial compression tests were performed on ice samples from ten multi-year pressure ridges to examine the magnitude and variation of ice strength within and between pressure ridges. A limited number of constant-strain-rate compression and tension tests, constant-load compression tests, and conventional triaxial tests were also performed on ice samples from a multi-year floe to provide preliminary data for developing ice yield criteria and constitutive laws for multi-year sea ice. Data are presented on the strength, failure strain, and modulus of multi-year sea ice under different loading conditions. The statistical variation of ice strength within and between pressure ridges is examined, as well as the effects of ice temperature, porosity, structure, strain rate and confining pressure on the mechanical properties of multi-year sea ice.
    Type of Medium: Series available for loan
    Pages: v, 107 Seiten , Illustrationen
    Series Statement: CRREL Report 84-9
    Language: English
    Note: CONTENTS Abstract Preface Introduction Field Sampling Site selection and description Ice sampling procedures Shipping and storage of ice samples Testing Techniques Multi-year Pressure Ridge Tests Ice description Sampling scheme and test variables Uniaxial compressive strength Residual compressive strength Failure strains Initial tangent modulus Statistical Variations in Ice Strength Differences in strength above and below level ice Sources of the variation in strength Shape of the strength histograms Multi-year Floe Ice Tests Ice description Uniaxial compressive strength Constant-load compression tests Constant-strain-rate tension tests Triaxial tests Conclusions Literature Cited Appendix A: Structural profile of a multi-year pressure ridge core Appendix B: Ridge uniaxial compression test data Appendix C: Structural profile of the continuous multi-year floe core Appendix D: Multi-year floe test data
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  • 95
    Call number: ZSP-201-86/12
    In: CRREL Report, 86-12
    Description / Table of Contents: Stress-deformation data for six granular soils ranging from sandy silt to dense-graded crushed stone were obtained from in-situ tests and laboratory tests. Surface deflections were measured in the in-situ tests, with repeated-load plate-bearing and falling-weight deflectometer equipment, when the six granular soils were frozen, thawed, and at various stages of recovery from thaw weakening. The measured deflections were used to judge the validity of procedures developed for laboratory triaxial tests to determine nonlinear resilient moduli of specimens in the frozen, thawed, and recovering states. The validity of the nonlinear resilient moduli, expressed as functions of externally applied stress and moisture tension, was confirmed by using the expressions to calculate surface deflections that were found to compare well with deflections measured in the in-situ tests. The tests on specimens at various stages of recovery are especially significant because they show a strong dependence of the resilient modulus on moisture tension, leading to the conclusion that predictions or in-situ measurements of moisture tension can be used to evaluate expected seasonal variation in the resilient modulus of granular soils.
    Type of Medium: Series available for loan
    Pages: v, 70 Seiten , Illustrationen
    Series Statement: CRREL Report 86-12
    Language: English
    Note: CONTENTS Abstract Preface Introduction Sampling of test section Laboratory tests Asphalt concrete Natural subgrade material Test soils Field tests Analysis of field-loading tests Discussion Conclusions Literature cited Appendix A: Field data Appendix 8: Ground temperatures prevailing during plate-loading tests Appendix C: Measured surface deflections compared with deflections calculated by NELAPAV Appendix D: Resilient moduli and supporting data calculated by NELAPAV
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  • 96
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-84/26
    In: CRREL Report, 84-26
    Description / Table of Contents: Observations of shore ice pile-up and ride-up along the Alaska Beaufort Sea coast in 1983 and 1984 are presented. New information on historical accounts of onshore ice movement, uncovered since publication of Part I in this series, is reported. An account is given of ice overtopping a concrete caisson exploration island in the Canadian Beaufort Sea.
    Type of Medium: Series available for loan
    Pages: iii, 33 Seiten , Illustrationen
    Series Statement: CRREL Report 84-26
    Language: English
    Note: CONTENTS Abstract Preface Introduction Observations Discussion Literature cited Appendix A: Site location maps
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  • 97
    Call number: ZSP-201-82/39
    In: CRREL Report, 82-39
    Description / Table of Contents: Observations of a 4.4-m-high brine step in the McMurdo Ice Shelf, Antarctica, show that it has migrated about 1.2 km in 4 years. The present brine wave is overriding an older brine-soaked layer. This migration is proof of the dynamic nature of the step, which is the leading edge of a brine wave that originated at the shelf edge after a major break-out of the McMurdo Ice Shelf. The inland boundary of brine penetration is characterized by a series of descending steps that are believed to represent terminal positions of separate intrusions of brine of similar origin. The inland boundary of brine percolation is probably controlled largely by the depth at which brine encounters the firn/ ice transition (43 m). However, this boundary is not fixed by permeability considerations alone, since measurable movement of brine is still occurring at the inland boundary. Freeze-fractionation of the seawater as it migrates throught the ice shelf preferentially precipitates virtually all sodium sulfate, and concomitant removal of water by freezing in the pore spaces of the infiltrated firm produces residual brines approximately six times more concentrated than the original seawater.
    Type of Medium: Series available for loan
    Pages: v, 35 Seiten , Illustrationen
    Series Statement: CRREL Report 82-39
    Language: English
    Note: CONTENTS Abstract Preface Introduction Objectives Analytical techniques Radio echo profiling Core drilling Results and discussion Brine infiltration survey Brine layer steps Brine infiltration characteristics Brine infiltration mechanisms at inland boundary Confirmation of brine depths by drilling Density and temperature profiles Ice shelf freeboard Brine upwelling Brine chemistry Conclusions Literature cited
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  • 98
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    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-82/38
    In: CRREL Report, 82-38
    Description / Table of Contents: Extreme cold causes heavy buildup of frost, ice and condensation on many windows. It also increases the incentive for improving the airtightness of windows against heat loss. Our study shows that tightening specifications for Alaskan windows to permit only 30% of the air leakage allowed by current American airtightness standards is economically attractive. We also recommend triple glazing in much of Alaska to avoid window icing in homes and barracks. We base our conclusions on a two-year field study of Alaskan military bases that included recording humidity and temperature data, observing moisture accumulation on windows and measuring airtightness with a fan pressurization device.
    Type of Medium: Series available for loan
    Pages: v, 26 Seiten , Illustrationen
    Series Statement: CRREL Report 82-38
    Language: English
    Note: Contents Abstract Preface Nomenclature Introduction Previous work in cold weather window performance Investigation Data acquisition and analysis Modeling the window thermal regime Moisture and ice observations Airtightness testing and analysis Annual heat loss from air leakage Results and conclusions Moisture on windows Airtightness Airtightness economics Recommendations for windows in extreme cold Airtightness Multiple glazing Literature cited Appendix A: Moisture levels and airtightness Appendix B: Dewpoint data Appendix C: Sample observations of icing
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  • 99
    Call number: ZSP-201-82/37
    In: CRREL Report, 82-37
    Description / Table of Contents: This report presents a Landsat-derived land cover map of the northwest portion of the Arctic National Wildlife Refuge, Alaska. The report is divided into two parts. The first is devoted to the land cover map with detailed descriptions of the mapping methods and legend. The second part is a description of the study area. The classification system used for the maps is an improvement over existing methods of describing tundra vegetation. It is a comprehensive method of nomenclature that consistently applies the same criteria for all vegetation units. It is applicable for large- and small-scale mapping and is suitable for describing vegetation complexes, which are common in the patterned-ground terrain of the Alaskan Arctic. The system is applicable to Landsat-derived land cover classifications. The description of the study area focuses on five primary terrain types: flat thaw-lake plains, hilly coastal plains, foothills, mountainous terrain, and river flood plains. Topography, landforms, soils and vegetation are described for each terrain type. The report also contains area summaries for the Landsat-derived map categories. The area summaries are generated for the five terrain types and for the 89 townships within the study areas. Two land cover maps at 1:250,000 are included.
    Type of Medium: Series available for loan
    Pages: 68 Seiten , Illustrationen, 2 Karten
    Series Statement: CRREL Report 82-37
    Language: English
    Note: CONTENTS Abstract Preface Foreword Introduction A land cover map of the ANWR study area Legend development Mapping method Results Discussion Description of the ANWR study area General description Description of specific terrain types Conclusions Literature cited Appendix A: Descriptions of Landsat land cover categories for ANWR Appendix B: Area summaries Appendix C: Aproximate equivalent units in several systems of land cover, wetland and vegetation classifications used in northern Alaska Appendix D: Soil taxonomy Appendix E: Summary of principal Landsat land cover categories within the terrain types of the ANWR study area
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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-201-82/36
    In: CRREL Report, 82-36
    Description / Table of Contents: Camp construction and drilling activities in 1950 at the East Oumalik drill site in northern Alaska caused extensive degradation of ice-rich, perennially frozen silt and irreversible modification of the upland terrain. In a study of the long-term degradational effects at this site, the near-surface geology was defined by drilling and coring 76 holes (maximum depth of 34 m) in disturbed and undisturbed areas and by laboratory analyses of these cores. Terrain disturbances, including bulldozed roads and excavations, camp structures and off-road vehicle trails, were found to have severely disrupted the site's thermal regime. This led to a thickening of the active layer, melting of the ground ice, thaw subsidence and thaw consolidation of the sediments. Slumps, sediment gravity flows and collapse of materials on slopes bounding thaw depressions expanded the degradation laterally, with thermal and hydraulic erosion removing materials as the depressions widened and deepened with time. Degradational processes became less active after thawed sediments thickened sufficiently to slow the increase in the depth of thaw and permit slope stabilization. The site's terrain is now irregular and hummocky with numerous depressions. Seasonal thaw depths are deeper in disturbed areas than in undisturbed areas and reflect the new moisture conditions and morphology. The severity of disturbance is much greater at East Oumalik than at another old drill site, Fish Creek. The difference results primarily from differences in the physical properties of the sediments, including the quantity and distribution of ground ice.
    Type of Medium: Series available for loan
    Pages: 42 Seiten , Illustrationen
    Series Statement: CRREL Report 82-36
    Language: English
    Note: CONTENTS Abstract Preface Summary Introduction Methodology Geologic setting Camp construction and occupation Types of disturbance Degradational processes and the effective area of impact Areal effects of disturbance Topography Groundwater, surface water and drainage Sediment properties and near-surface stratigraphy Surficial processes Depth of thaw Comparison to Fish Creek Discussion and conclusions Literature cited
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