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  • Wissenschaftspark Albert Einstein  (140)
  • Bibliothek des Konservatismus
  • SKB Bad Freienwalde
  • Forschungsbericht  (140)
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  • 1
    UID:
    kobvindex_GFZ107347
    Format: 97 Seiten
    Series Statement: SIPRE report 10
    Note: MAB0014.001: ZSP-201-10 , Contents Foreword Synopsis Introduction Authority Purpose and scope SIPRE organization and activities Cryological problems and military end points Present state of knowledge General Introduction Terminology and classification Snow and ice Introduction Physical properties and geometry Density and water equivalent Water holding or storage capacity of snow Water transmission through snow Bound water Crystallography and metamorphism Porosity and permeability Mechanical properties Elasto-plastic properties Friction Strength Hardness Electromagnetic properties Dielectric constants Conductivity Magnetic properties Piezoelectric and pyroelectric effects Triboelectricity Freezing potential Thermodynamic properties Thermal properties Radiation Phase relations Engineering problems Snow and ice removal Snow compaction Snow draft control Trafficability Temporary structures Snow melt and runoff Maps Frozen ground and permafrost Introduction Frost action Theory of frost action Cyclic freezing and thawing Manifestations of frost actions Frost heave on freezing Reduction in load-carrying capacity on thawing Soil movements on slopes Ground properties affecting or affected by frost action Composition, grain size, and grain-size distribution Soil-moisture-movement properties Thermal properties Structure of unfrozen ground Structure of frozen ground Strength of frozen ground Freezing point Ground conditions affecting or affected by frost action Density Degree of saturation Interrelation of climate, position, vegetation, and soil Frost phenomena Climate Position Vegetation Engineering problems Excavation and replacement Subsurface drainage Base courses Insulation courses Surface icing and its control Trafficability Building foundations Maps Current related research Introduction Military cryological research in United States and Canada Non-military cryological research in the Western World Research needed Introduction Subjects for fundamental research Subjects for applied research
    In: SIPRE report, 10
    Language: English
    Keywords: Forschungsbericht
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  • 2
    UID:
    kobvindex_GFZ20190417101919
    Format: 44 Seiten , Illustrationen
    Series Statement: CRREL Report 82-31
    Content: 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.
    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
    In: CRREL Report, 82-31
    Language: English
    Keywords: Forschungsbericht
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  • 3
    UID:
    kobvindex_GFZ20200304155051
    Format: iv, 21 Seiten , Illustrationen
    Series Statement: CRREL Report 79-21
    Content: The report studies the question of whether Great Lakes freighters could move effectively through ice-clogged channels with the aid of tows provided by warping or kedging systems. Ten operational concepts are outlined, and their advantages and disadvantages are noted. The crushing resistance of floating brash ice is then analyzed. The neutral, active and passive states of stress for laterally confined brash ice are considered, and the resistance to horizontal thrusting by a smooth vertical wall is calculated for cohesionless brash ice, and for ice in which there is finite cohesion between the ice fragments. The thickening of the ice cover in the vicinity of a "pusher", and the formation of pressure ridges, are analyzed in order to estimate the amount of pile-up that can occur against a ship hull. The analysis then moves on to consideration of ship resistance by brash ice, taking into account crushing resistance at the bow, tangential friction at the bow, and hull friction aft of the bow section. Comparisons are made between thrust from the ship’s screws and the calculated ice resistance. The next section of the report estimates the force requirements for a warping or kedging system in terms of thrust augmentation for existing vessels. Tow cable requirements are given, and estimates are made for cable anchors and for anchorage of underwater structures. The force and power requirements for winches and windlasses are given, the practical problems involved in the pickup or transfer of cables are mentioned, and the report concludes with a brief appraisal. The conclusion is that a simple warping tug system is appropriate for a full scale experiment, a chain ferry with auxiliary barge seems attractive for an operational system, and a chain ferry plow may be an efficient way to clear ice from channels.
    Note: CONTENTS Abstract Preface Introduction Operational concepts A. Warping tug system B. Chain ferry system C. Chain ferry with auxiliary barge D. Ski tow system E. Dual winch warping system F. Simple kedging G. Trailing-line system H. Above-surface dual winch system I. Pulley systems J. Chain ferry plow Crushing resistance of fragmented ice covers Resistance to ship passage by broken ice Crushing resistance at the bow Tangential friction at the bow Hull friction aft of the bow section Total ship resistance from brash ice Comparison of ship thrust and ice resistance Force requirements for a warping or kedging system Tow cable requirements Anchors and anchorages Force and power requirements for winches and windlasses Pickup or transfer of cable General appraisal Literature cited
    In: CRREL Report, 79-21
    Language: English
    Keywords: Forschungsbericht
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  • 4
    UID:
    kobvindex_GFZ106417
    Format: xi, 85 Seiten , Illustrationen
    Series Statement: CRREL Report 77-7
    Content: The report deals with the cutting of rock and similar materials by parallel motion tools. It examines cutting forces and energy requirements, taking into consideration tool geometry, wear, operating conditions, and material properties. After an introductory discussion of terminology, some general principles are outlined, and relevant theoretical ideas on metal cutting and rock cutting are reviewed. The next section, which is the heart of the report, reviews experimental data on the magnitudes and directions of cutting forces. There is a graphical compilation of data, including some from obscure or unpublished sources. The variables covered include chipping depth, rake angle, relief angle, side rake, base angle, tool width, tool compliance, tool speed, tool wear, tool interactions, and material properties. The second major part of the report treats the energetics of cutting. It begins with a short discussion of relevant principles, and continues with a compilation and review of experimental data, covering the same independent variables as the force section. The report ends with a concise summary of general behavior for parallel motion tools.
    Note: MAB0014.001: ZSP-201-77/7 , CONTENTS Abstract Preface Foreword Introduction Terminology Principles of cutting Forces acting on a single cutter Theoretical Ideas on cutting Experimental data on cutting forces Effect of chipping depth on tool forces Effect of rake angle on tool forces Effect of relief angle on cutting forces Effect of side rake on tool forces Effect of base angle or face profile on tool forces Effect of rounding at the cutting edge Effect of tool width on cutting forces Tool compliance and force fluctuations Effect of tool speed on cutting forces Effect of rock properties on cutting forces Tool interaction and kerf spacing Effect of multiple pass cutting on tool forces Effect of tool wear on cutting forces Development of wear Energetics of cutting Energetics of parallel-motion tools Variation of specific energy with chipping depth for a single tool Effect of rake angle on specific energy Effect of relief angle on specific energy Effect of side rake on specific energy Effect of base angle or face profile on specific energy Effect of tip radius on specific energy Effect of tool width on specific energy Effect of tool speed on specific energy Variation of specific energy with rock properties Effect of kerf spacing on specific energy Effect of multiple pass cutting on specific energy Effect of tool wear on specific energy General summary Literature cited Appendix Α. Additional data for ice Appendix Β. Conversion factors: U.S. customary and metric units of measurement
    In: CRREL Report, 77-7
    In: Mechanics of cutting and boring, IV
    Language: English
    Keywords: Forschungsbericht
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  • 5
    UID:
    kobvindex_GFZ20201209134041
    Format: viii, 79 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 88
    Content: Summary: Four ground patterns were investigated by means of trenches cut in the outwash near Thule, Greenland: circular and linear depressions in unsorted material, polygonal troughs in unsorted material, sorted circles, and irregular mounds and depressions of low relief formed in unsorted finer grained material. Correlation is made between surface pattern, grain size and structure of the active layer, and type and distribution of ground ice for the patterns investigated. Classification of the active layer as disturbed, slightly disturbed, and undisturbed is based on the condition of primary depositional bedding and the presence or absence of vertical sorting. Other features of the active layer, depending upon its type, are an accumulation of fines at the bottom of the active layer and on top of stones, and a siliceous calcareous evaporite on the under surface and clean washed coarser particles beneath the larger stones. Fabric analysis of four kinds of ground ice is presented: ice wedge, relict ice, ice mass, and ice lens, as well as analysis of the contact of ice wedges with relict and mass ice. Practical applications, based on the conclusions, are given for the selection of foundation sites and the location of non-frost-susceptible building materials. NOTE: This is a very large file. Please give your browser several minutes to download the file.
    Note: CONTENTS Preface Summary Introduction Glossary Part 1 : Surface pattern, structure of the active layer, and type and distribution of ground ice in the permafrost Pattern type 1: Circular and linear depressions in unsorted outwash Circular depressions, area 1 Structure of the active layer Ground ice and its relation to surface morphology Linear depressions, area 5 Structure of the active layer Ground ice and its relation to surface morphology Pattern t ype 2 and 3: Polygonal troughs in unsorted outwash and sorted circles or centers of fines Area 3 Structure of the active layer Ground ice and its relation to surface morphology Area 4 Structure of the active layer Ground ice and its relat ion to surface morphology Pattern type 4: Mounds and depressions of low relief in unsorted outwash Area 4a Structure of the active layer Ground ice and its relatiop. to surface morphology Part 2: Ground ice studies Area 1 Lens ice History Appearance of the ice Fabric analysis Wedge ice History Appearance of the ice Fabric analysis Relict ice History Appearance of the ice Fabric analysis Contact between ice wedge and relict ice Ice sockets Area 5 Wedge ice Fabric analysis Relict ice Fabric analysis Area 3 Ice mass History Appearance of the ice Fabric analysis Ice wedge Fabric analysis Contact between ice mass and wedge Appearance of the ice Fabric analysis Summary and conclusions Pattern type 1: Linear and circular depressions in. unsorted outwash Pattern type 2: Polygonal troughs formed in unsorted outwash Pattern type 3: Sorted circles or centers of fines Pattern type 4: Mounds and depressions of low relief in fine-grained unsorted outwash Engineering applications References Appendix A: Associated studies Appendix B : Recommendations for further field and laboratory work Appendix C: Recommendations for field and laboratory techniques
    In: Research report / Cold Regions Research and Engineering Laboratory, 88
    Language: English
    Keywords: Forschungsbericht
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  • 6
    Book
    Book
    Hanover, New Hampshire : U.S. Army Material Command, Cold Regions Research & Engineering Laboratory
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    UID:
    kobvindex_GFZ070220191455
    Format: 16 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory, CRREL, US Army Material Command 145
    Content: An analysis is made of the time required to build up an ice-age ice sheet and of the time required to destroy such an ice sheet. The calculations are based on the approximation that the theory of perfect plasticity is valid. It is concluded that the time required to eliminate it. If it is assumed that the accumulation rate of an ice-age ice sheet lies of a large ic sheet is of the order of 15.000 to 30.00 years. Ablation rates of 1 to 2 meters/year lead to shrinkage times of the order of 2000 to 4000 years, provided ablation occurs over an appreciable area of the ice sheet.
    Note: Contents: Preface. - Summary. - Introduction. - Basis of theory. - Basic equations. - Ice sheets with only accumulation or ablation. - Growing ice sheets which contain only an accumulation zone. - Shrinking ice sheets which contain only an ablation zone. - Comments. - Ice sheet with both accumulation and ablation zones. - Growing ice sheets. - Shrinking ice sheets. - Conclusions. - References.
    In: Research report / Cold Regions Research and Engineering Laboratory, CRREL, US Army Material Command, 145
    Language: English
    Keywords: Forschungsbericht
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  • 7
    Book
    Book
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    UID:
    kobvindex_GFZ20190521145858
    Format: iv, 39 Seiten , Illustrationen , 1 Beilage
    Series Statement: CRREL Report 83-30
    Content: Ice sheets are formed and retained in several ways in nature, and an understanding of these factors is needed before most structures can be successfully applied. Many ice sheet retention structures float and are somewhat flexible; others are fixed and rigid or semirigid. An example of the former is the Lake Erie ice boom and of the latter, the Montreal ice control structure. Ice sheet retention technology is changing. The use of timber cribs is gradually but not totally giving way to sheet steel pilings and concrete cells. New structures and applications are being tried but with caution. Ice-hydraulic analyses are helpful in predicting the effects of structures and channel modifications on ice cover formation and retention. Often, varying the flow rate in a particular system at the proper time will make the difference between whether a structure will or will not retain ice. The structure, however, invariably adds reliability to the sheet ice retention process.
    Note: Contents Abstract Preface Introduction Natural ice sheets Choosing an ice control structure Flexible structures Ice booms Frazil collector lines Fence booms Rigid or semirigid structures Pier-mounted booms Stone groins Artificial islands Removable gravity structures Timber cribs Weirs Pilings and dolphins Structures built for other purposes Hydroelectric dams Wicket dams Light piers and towers Bridge piers Breakwaters Ice control not using Structures Channel improvements Ice sheet tying Ice sheet bridges Conclusions Literature cited Appendix A: Ice control structure
    In: CRREL Report, 83-30
    Language: English
    Keywords: Forschungsbericht
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  • 8
    Book
    Book
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    UID:
    kobvindex_GFZ20210210103940
    Format: 38 Seiten , Illustrationen
    Series Statement: CRREL Report 81-17
    Content: 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
    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
    In: CRREL Report, 81-17
    Language: English
    Keywords: Forschungsbericht
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  • 9
    UID:
    kobvindex_GFZ20201202153738
    Format: vi, 48, A4 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 66
    Content: Summary: A simple theory is proposed for crack formation and development by soil desiccation on the basis of laboratory experiments utilizing soil samples (Bloomington till) with max particle size of 1 mm diam. held in flat wooden containers. The crack pattern is more dependent on the thickness of the soil sample than on temperature or humidity. Some effect is caused also by differences in the bottom material of the containers. The area of cells made by crack patterns has a log normal size distribution. Total length of cracks decreases with increase in sample thickness. The number of sides of cells also depends on the thickness. Cracking was found to begin from the center of the soil layer and to propagate to the surface or bottom with non-uniform speed.
    Note: CONTENTS Preface Summary Introduction Soil material Soil Preparation of the soil material Containers Temperature and humidity of the air Moisture content and dry density of the soil Experimental procedures and results General procedures Definition of the characteristics of cracking of soil Cracking moisture content Size of cells made by cracking of the soil Length of cracks Number of sides of cells Development of cracks Additional experiments Interfacial fracture markings Method of auxilliary tests on physical properties of the soil Elastic constants of the soil Shrinkage of soil due to desiccation Tests of the adhesion between the soil and the bottom material Results of auxiliary tests Elastic constants of the soil Free shrinkage process of the soil due to desiccation Adhesion between the soil and glass or wood Mechanism of crack formation due to the desiccation of soil Geometric interpretation Mechanical interpretation Conclusions References Appendix: Table of experiments
    In: Research report / Cold Regions Research and Engineering Laboratory, 66
    Language: English
    Keywords: Forschungsbericht
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  • 10
    Book
    Book
    Wilmette, Ill. : Snow Ice and Permafrost Research Establishment, Corps of Engineers, U.S. Army
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    UID:
    kobvindex_GFZ20201111113738
    Format: vi, 92 Seiten , Illustrationen , 27 cm
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 27
    Content: Summary: The results of a study on the feasibility of mapping selected snow-cover characteristics for military purposes, taking into account both current synoptic and average conditions, are reported in detail. Problems associated with the construction of isolines for depicting individual or combination of snow-cover conditions are discussed; the need for other statistical parameters in addition to the means is stressed; and the adaptation of frequency and variability indices is suggested. The use of a regional technique, which identified areas somewhat homogenous or substantially different from adjacent areas, is investigated. Problems in mapping snow density are also considered as well as the possibility of estimating snow density from meteorological data. Three sets of codes for the systematic recording and transmission of data are proposed, including a code for ground observers, a simplified code for use where no instruments or trained personnel are available, and a code for aerial observations.
    Note: TABLE OF CONTENTS PREFACE LIST OF TABLES LIST OF ILLUSTRATIONS INTRODUCTION Chapter I. APPLICATION OF ISOLINES FOR DEPICTING ASPECTS OF THE SNOW COVER Visual Problems Use of a simplified base map Other solutions Substantive Problems Observational errors Sampling errors Bias error Effect of reliability of data on isolines Conclusion The ''reasoned distribution'' Effects of substantive problems Conclusion II. DEVELOPMENT OF OTHER MEASURES, INDICES, AND METHODS FOR DEPICTING SNOW COVER CONDITIONS Examples of Possible Normal Indices of Snow Cover Average snow depth at end of the maximum month Average monthly snow depths by superimposed or located line graphs Time aspects Snowfall Selected Statistical Parameters of a Particular Value Extreme values Frequency values Measures of variability Conclusion III. SNOW REGIONS: AN APPROACH TO MAPPING SNOW COVER Snow Region Concept Descriptions of Snow Regions 1. Pacific Coast and Coastal Valley Region 2. The Mountain Zone 3. Great Plains Region 4. The Mackenzie-Manitoba Region 5. Upper Ontario Region 6. Northern Great Lakes-St. Lawrence Region 7. Labrador Region 8. The Northern Arctic Region 9. Ungava-Baffinland Region Conclusions IV. CURRENT SNOW DATA MAPS Introduction Ground Observer's Code Suggested code for "Ground Observer's Snow Report" Comments Symbols for a comprehensive station model Air Observation Code Comments Station Model for Aircraft Snow Observations A Simplified Snow Observation Report . Introduction Proposed code and symbols for station model based on Simplified Snow Observation Report Conclusion Chapter V. MAPPING SNOW DENSITY Introduction Limitations of Data for Mapping Available data Reliability of the data Natural variations in density Snow Density Maps of Eastern Canada Statistical Investigation of Density: Eastern Canada Test for area differences Estimating regional trends in density: Orthogonal polynomials Regional density changes during the winter Conclusions: Statistical investigations Estimating Snow Density from Meteorological Data Relation of density to wind speed and temperature Application of Dmitrieva's equation Conclusion VI. CONCLUSION Snow Cover Maps: Small Scale Compilations of Various Aspects of Their Parameters Preparation of Synoptic Current Snow Data Maps Snow Density Research Investigation of Drift and Erosional Surfaces Initiation of Systematic Collection and Recording of Snow Data Internationally Research Reports Based on Existing Literature .
    In: Research report / Cold Regions Research and Engineering Laboratory, 27
    Language: English
    Keywords: Forschungsbericht
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