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  • 1
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-202-108
    In: Research report / Cold Regions Research and Engineering Laboratory, 108
    Description / Table of Contents: Summary: The theory of snow densification is further developed on the basis of an exponential relation between viscosity and density. A linear relation between load-stress and strain rate is not valid for high stresses, and is replaced by a hyperbolic sine function. An empirical function is given for the temperature cycle correction. Two equations are derived for calculating depth-density curves with computers, and a simplified one for use with desk calculators. Instructions are given for determination of function parameters from field data. Four depth-density curves for Greenland and Antarctic locations are computed and graphed to show that the theory is useful.
    Type of Medium: Series available for loan
    Pages: iv, 18, A3, B5 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 108
    Language: English
    Note: CONTENTS Preface Summary Introduction Notation Stress analysis Analysis of densification process Non-Newtonian densification Equation for hyperbolic sine densification law Determination of parameters Discussion Glaciological engineering aspects References Appendix A: Example of calculation Appendix B: Snow density profiles
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  • 2
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-202-110
    In: Research report / Cold Regions Research and Engineering Laboratory, 110
    Description / Table of Contents: Summary: Nafe's (1957) presentation of reflection and transmission coefficients at a solid-solid interface was used to compute tables for the case of ice in contact with another solid at a plane interface. Energy ratios of all the combinations of reflected and refracted plane P and S waves were computed for 30 different cases of the second solid. A compressional velocity of 3.6 km/sec, a density of 0.9 g/cm^3, and a value of 1/3 for Poisson's ratio were assumed for the ice. For the other solid, the velocity ranged from 1.2 to 6.0 km/sec, the density from 1.5 to 3.0 g/cm^3, and Poisson's ratio from 0 to 1/3. The computations were carried out with an electronic computer, and the results are presented graphically.
    Type of Medium: Series available for loan
    Pages: iv, 17 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 110
    Language: English
    Note: CONTENTS Preface Summary Introduction Definitions Computation Results
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  • 3
    Call number: ZSP-202-111,1
    In: Research report / Cold Regions Research and Engineering Laboratory, 111,1
    Description / Table of Contents: Summary: Optical scintillation, visual resolution, and wind and temperature profiles were measured over snow, ice and frozen ground. The data were analyzed to determine relationships between (1) scintillation and visual resolution and (2) scintillation and meteorological and surface conditions. The experimental results included (1) estimates of the limit of visual resolution, (2) telephotometer measurements of the apparent fluctuations in brightness (scintillation) of an artificial light source, and (3) measurements of wind direction and of the vertical distributions of wind speed and temperature. The optical path was 543 m long and 1.5 m above uniform horizontal surfaces. All scintillation and meteorological data are given in an appendix. The principal results of the analysis showed that for turbulent flow in stable stratification over snow (1) visual resolution deteriorated systematically as scintillation increased in intensity and (2) scintilliation intensity increased with increase in vertical temperature gradient. Scintilliation was at a minimum in the absence of thermal stratification and at a maximum (in very stable thermal stratification) during the sudden transition from laminar to turbulent flow. For a given temperature gradient, scintilliation increased with increase in wind speed. When wind and temperature gradients were combined in terms of the Richardson number and related to scintilliation, the data obtained over snow indicated a critical Richardson number of about 0.35. Scintilliation power spectra for eight periods revealed characteristics that could be related to visual resolution, the Richardson number and the mean wind speed component normal to the optical path. NOTE: This file is large. Allow your browser several minutes to download the file.
    Type of Medium: Series available for loan
    Pages: iii, 32, A17, B44 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 111,1
    Language: English
    Note: CONTENTS Preface Page Summary Introduction The problem Previous work Plan of the investigation Conclusions Visual resolution and scintillation Visual resolution and wind, temperature, and surface conditions Visual resolution and height and length of optical path Results Measurements Analysis and discussion Visual resolution and scintillation relationships Scintillation and micrometeorological parameters Index of refraction fluctuations Scintillation and the temperature profile Scintillation and average wind speed Combined effects of wind speed and temperature gradient Scintillation and surface roughness Scintillation power spectra Scintillation and path length References Appendix A: Equipment and procedures Appendix B: Micrometeorological and scintillation data
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  • 4
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-202-109
    In: Research report / Cold Regions Research and Engineering Laboratory, 109
    Description / Table of Contents: Summary: The present paper contains a critical study of a number of foundation models suggested by various investigators, as well as a further development of some of the ideas involved. It is found that the model by Pasternak is the most natural extension of the Winkler foundation. It is also shown that the "non-solvability" of the problem of a finite bean or plate resting on a continuous foundation as posed by Wieghardt and further elaborated by Pflanz is not correct, and that problems of this type are solvable for any load distribution permissible in classical plate theory. The paper concludes with derivations of differential equations for plates resting on viscous and viscoelastic foundations, which may be used for solving problems involving compacted snow and permafrost bases.
    Type of Medium: Series available for loan
    Pages: iv, 15 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 109
    Language: English
    Note: CONTENTS Preface Summary Introduction The Hetényi foundation The Filonenko-Borodich foundation The Pasternak foundation Plates on a Pasternak foundation Visco-elastic Pasternak foundation Plates on visco-elastic foundations References Appendix A: Notation
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  • 5
    Call number: ZSP-202-111,2
    In: Research report / Cold Regions Research and Engineering Laboratory, 111,2
    Type of Medium: Series available for loan
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 111,2
    Language: English
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  • 6
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-202-112
    In: Research report / Cold Regions Research and Engineering Laboratory, 112
    Description / Table of Contents: Summary: The age hardening of artificially and naturally compacted snow has been investigated at the South Pole. Results show that the age-hardening process is greatly retarded at low temperatures. Artificially compacted samples of density 0.55 g/cm^3 attained a compressive strength of less than 3.0 kg/cm^2 after one year's aging at -49°C. Exposure to solar radiation accelerated the age hardening. Irradiated samples attained a strength of 6.0 kg/cm^2 after 100 hr, increasing to a virtual maximum of 8.0 kg/cm^2 at 600 hr. Compressive strengths increased witha decrease in snow-particle size and with an increasing angularity of the particles. Below 3 m the strength of naturally compacted snow was found to increase rapidly with an increase in density. Naturally compacted snow of density 0.55 g/cm^3 possessed considerably greater strength than any of the age-hardened samples of artificially compacted snow of the same density. Thin-section studies show that age hardening can be correlated with the formation and growth of intergranular bonds, and that bond growth falls off rapidly with decreasing temperature. In view of the low strength found in both naturally and artificially compacted snow at the South Pole, "cut-and-cover" undersnow camp construction may not prove practical at the South Pole.
    Type of Medium: Series available for loan
    Pages: v, 19, A6 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 112
    Language: English
    Note: CONTENTS Preface Summary Introduction Previous work Experimental methods Experimental results Series A Series B Series C Series D Series E Discussion Conclusions References Appendix A
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  • 7
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-202-99
    In: Research report / Cold Regions Research and Engineering Laboratory, 99
    Description / Table of Contents: Summary: A study of how age hardening affects the various mechanical properties of processed snow was made. A description of how the age hardening process is affected by the variables of density, temperature, grain size, and shape is given. An empirical equation relating creep rate to stress, age, and density was obtained. The study also shows that the various mechanical properties are related to age by an exponential function.
    Type of Medium: Series available for loan
    Pages: iv, 12 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 99
    Language: English
    Note: CONTENTS Preface Summary Introduction Experimental facilities Experimental in-place measurements Density and homogeneity of processed snow Ram hardness Temperature measurements Mechanical properties Unconfined compressive strength Stress-strain relationships in unconfined compress ion Creep in unconfined compression Tensile strength Discussion of results References
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  • 8
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-202-101
    In: Research report / Cold Regions Research and Engineering Laboratory, 101
    Description / Table of Contents: Partial Summary: This paper is a pilot study of interrelations between structural features readily observed in horizontal thin sections of sea ice under low magnification. The core studied was 31.4 cm in length and was collected from Elson Lagoon at Point Barrow, Alaska on 26 October 1960.
    Type of Medium: Series available for loan
    Pages: iv, 11 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 101
    Language: English
    Note: CONTENTS Preface Summary Introduction Petrographic characteristics Intercrystalline features Intracrystalline features References
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  • 9
    Call number: ZSP-202-100
    In: Research report / Cold Regions Research and Engineering Laboratory, 100
    Description / Table of Contents: From the Summary: During the summer of 1960, observations were made of ground fog on the Greenland Ice Cap and of sea fog in the Thule area in northwestern Greenland. A microscope-stage-fog impactor was designed, and its collection efficiency determined both empirically and by computation from the theoretical work of Langmuir and Blodgett (1946). The empirical efficiency was found to be considerably greater than the theoretical efficiency.
    Type of Medium: Series available for loan
    Pages: iv, 13 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 100
    Language: English
    Note: CONTENTS Preface Summary Introduction Method Design and operation of the impactor Collection efficiency Computation from theoretical values of Langmuir and Blodgett Empirical values Observations and results Fog on the ice cap Sea fog near Thule Discussion Conclusions References
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  • 10
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-202-103
    In: Research report / Cold Regions Research and Engineering Laboratory, 103
    Description / Table of Contents: Summary: The effect of air flow on the thermal conductivity of snow was investigated. Steady-state temperature measurements were made along the edge and axis of a cylindrical bed of snow to determine the effective axial thermal conductivity of snow. Unconsolidated snow samples were used, with densities ranging from 0.376 to 0.472 g/cm^3 and corresponding snow particle sizes of 0.065 to 0.219 cm nominal diameter; the mass flow rates employed ranged from approximately 10-40 x 10^-4g/cm^2 sec. Snow density and sample size apparently have opposite effects on the effective thermal conductivity because of the flow of fluid in snow. The test apparatus is described in detail and is illustrated. The results of the experiments are tabulated, and a least square equation is given which represents the results well.
    Type of Medium: Series available for loan
    Pages: iv, 14, A2 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 103
    Language: English
    Note: CONTENTS Preface Summary Introduction Theory Apparatus and experimental procedure Results and discussion References Appendix A: Sample calculations of a and ke
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