Kooperativer Bibliotheksverbund

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Format: XII, 510 S. : , zahlr. Ill. und graph. Darst.

Content: Work at Dept. of Physics, Hokkaido University, Japan. Comprehensive work on the nature of snow. Different shapes of snow crystals are described and classified.

Language: English

Keywords: Schneekristall ; Schnee

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Format: XII, 510 S. 4"

Language: Undetermined

Keywords: Niederschlag ; Meteorologie ; Physik

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Format: 68p , 19cm

Edition: 初版

Original writing title: どんぐり

Original writing title: ドングリ

Original writing person/organisation: 寺田, 寅彦

ISBN: 9784909992505

Series Statement: Tōkōsha hon no tomoshibi

Content: 科学者として活躍しながら、随筆家としても数々の名筆を残した寺田寅彦と中谷宇吉郎。寺田の「どんぐり」「コーヒー哲学序説」、中谷の「「団栗」のことなど」の3編を収録した、味わい深い随筆の世界へと誘う一冊。

Content: どんぐり コーヒー哲学序説 / 寺田寅彦著 -- 『団栗』のことなど / 中谷宇吉郎著

Note: 装幀: 野田和浩

Language: Japanese

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Format: vi, 32 Seiten , Illustrationen

Series Statement: Research report / Cold Regions Research and Engineering Laboratory 89

Content: Abstract: Experiments were carried out near Thule, Greenland, on the correlation between the physical properties and internal structure of snow. About 150 snow samples obtained to 26 m depth were measured for elastic modulus, air permeability, unconfined compressive strength, static compression and creep. The observed density profile curve deviated from the theoretical curve at a depth of 10 m. and density of 0.52 g/cm^3, a value almost equivalent to the limiting density obtainable by simple mechanical packing. Therefore, further densification must proceed through plastic flow in grains. A similar critical depth was observed in the vertical distribution of Young's modulus. A positive correlation was found between Young's modulus and density, and an inverse correlation between average grain diameter and Young's modulus or density. There were reciprocal correlations between air permeability and density or unconfined compressive strength, and between the number of grains and their average diameters. Kozeny's constant of Greenland snow was obtained from air permeability values and the length of peripheries of cross sections of grains. To demonstrate the change of internal structure of snow due to densification, static compression tests of snow cylinders were conducted, and thin sections of snow texture were compared before and after compression. Creep curves of snow cylinders were analyzed using Nutting's formula and are discussed in connection with change of internal structure. Basal slip, buckling, cell or sub-grain formation, recrystallization and grain boundary migration occurring during plastic deformation of snow texture were observed by static compression of thin section snow under the microscope.

Note: CONTENTS Preface Nomenclature Introduction Experimental methods Density profile and densification Internal structure in typical samples Average grain size obtained from thin section Two-dimensional porosity, total pore periphery and tortuosity Vertical distribution of Young's modulus Air permeability and its structlU'al dependence Porosity dependence Grain size dependence Kozeny's constant for Greenland snow Correlation between air permeability and tortuosity of grains Unconfined compressive strength Static compression and creep in snow under high stresses Microscopic observation of the change in snow textlU'e under compression Literature cited Abstract

In: Research report / Cold Regions Research and Engineering Laboratory, 89

Language: English

Keywords: Forschungsbericht

URL: https://hdl.handle.net/11681/5874

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Format: v, 29, A4 Seiten , Illustrationen

Series Statement: Research report / Cold Regions Research and Engineering Laboratory 46

Content: Summary: The results of studies in the summer of 1957 on ice samples taken from the ice tunnel at TUTO, core samples obtained by drilling in the ice cap at Site 2, and snow samples, using the transverse vibration method and a new portable meter, are reported. Young's modulus was determined from the resonance frequency of flexural vibrations of samples cut in the form of rectangular bars; the loss factor was measured from damping; and the coefficient of viscosity calculated using the Maxwell model. The modulus of elasticity of samples of a density from 0.917 - 0.90 g/cm^3 (tunnel ice) decreased sharply with slight deviations of the density from that of pure ice. At densities from 0.90 - 0.50 g/cm^3 (deep-pit and drill-core samples) the relation between the modulus of elasticity and density was linear, while in the density range from 0.50-0.25 g/cm^3 (surface snow) the modulus of elasticity decreased exponentially. The viscosity-density relation of the samples was similar to that of elasticity vs density. Young's modulus increased slightly with decreasing temperature, while viscosity increased exponentially. The activation energy was calculated as 18.7 kcal/mol for old ice-cap ice, 13.9 kcal/mol for tunnel ice with elongated bubbles, and 13.5 kcal/mol for super-imposed ice.

Note: CONTENTS Preface Summary Introduction Principle of measuring the visco-elastic nature of snow and ice by the vibration method Experimental method for determination of visco-elastic properties of snow and ice Visco-elastic properties of tunnel ice Elastic properties of snow samples from the deep pit Elastic properties of core samples obtained by drilling Elastic properties of snow near the ice-cap surface Vertical variation of Young's modulus near the surface Wind-packed snow Peter snow Relation between Young's modulus and density of snow Relation between Young's modulus and density over the range from surface snow to ice Supplementary experiments on the elastic nature of snow and ice at Site 2 Anisotropy of Peter snow Age hardening Temperature dependence of Young's modulus of core ice Viscosity measurement of snow and ice in Greenland Further experiments on the elastic nature of tunnel ice Temperature dependence of Young's modulus Frequency dependence of Young's modulus Further experiments on the viscous nature of tunnel ice Temperature dependence of loss factor Activation energy Frequency dependence of loss factor and viscosity Relation between viscosity and density Conclusions References Appendix: Experimental data

In: Research report / Cold Regions Research and Engineering Laboratory, 46

Language: English

Keywords: Forschungsbericht

URL: https://hdl.handle.net/11681/2726

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Format: 163 S. : Ill., graph. Darst.

Series Statement: Mitteilungen der Deutschen Akademie der Luftfahrtforschung 2,1

Note: MAB0014.001: MOP 15017

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Format: 1 online resource(xii,510p.) : , illustrations.

Edition: Electronic reproduction. : Harvard University Press, 1954. Mode of access: World Wide Web.

Edition: System requirements: Web browser.

Edition: Access may be restricted to users at subscribing institutions.

ISBN: 9780674182769

Note: Frontmatter -- , Preface -- , Acknowledgments -- , Contents -- , Introduction -- , CHAPTER 1 Observation of Snow Crystals -- , CHAPTER 2 General Classification of Snow Crystals and Their Frequency of Occurrence -- , CHAPTER 3 Physical Properties of Snow Crystals -- , CHAPTER 4 Artificial Production of Frost Crystals -- , CHAPTER 5 Artificial Production of Snow Crystals -- , CHAPTER 6 Investigations on Artificial Snow -- , CHAPTER 7 Comparison of Natural and Artificial Snow Crystals -- , CHAPTER 8 Recent Researches on the Formation of Snow Crystals -- , APPENDIX CLASSIFICATION OF SNOW CRYSTALS FOR PRACTICAL PURPOSES -- , BIBLIOGRAPHY AND REFERENCES -- , Plates -- , INDEX OF NAMES -- , INDEX OF SUBJECTS. , Also available in print edition. , In English.

Additional Edition: ISBN 9780674182752

Language: English

DOI: 10.4159/harvard.9780674182769

URL: https://doi.org/10.4159/harvard.9780674182769