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  • Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory  (26)
  • Deutsches GeoForschungsZentrum GFZ  (22)
  • English  (48)
  • 1
    Call number: ZSP-202-315
    In: Research report
    Description / Table of Contents: CONTENTS: Preface. - Introduction. - Part 1:Mesoscale strain measurements on the Beaufort Sea pack ice. - Abstract. - Introduction. - Previous work. - Site location. - Results. - Correlation of synoptic aerial photography with measured strains. - Correlation of estimated wind stress and strain. - Conclusions. - Literature cited. - Part II: Structure of a multiyear pressure ridge. - Abstract. - Introduction. - Profiles. - Internal properties. - Largest ridge sail. - Conclusions. - Literature cited. - Part III: Top and bottom roughness of a multiyear ice floe. - Abstract. - Introduction. - Results. - Literature cited. - Part IV:Airphoto analysis of ice deformation in the Beaufort Sea Abstract. - Introduction. - Study area. - Method of analysis. - Ice deformations. - Net deformational changes. - Pressure ridge distribution. - Summary and conclusions. - Literature cited. - Part V: Data on morphological and physical characteristics of sea ice in the Beaufort Sea.
    Description / Table of Contents: Mesoscale strain measurements on the Beaufort Sea pack ice; Structure of a multiyear pressure ridge; Top and bottom roughness of a multiyear ice floe; Airphoto analysis of ice deformation in the Beaufort Sea; Data on morphological and physical characteristics of sea ice in the Beaufort Sea.
    Type of Medium: Series available for loan
    Pages: iii, 66 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory, CRREL, US Army Material Command 315
    Language: English
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  • 2
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-82/34
    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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  • 3
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-82/9
    In: CRREL Report, 82-9
    Description / Table of Contents: This study deals with the distribution of forces along the converging boundaries of the Port Huron, Michigan, region where unconsolidated ice in Lake Huron is held against wind and water stresses. An experimental basin was built to induce uniform shear stress on the model ice cover by flowing water beneath the ice. The boundary segments, which held the ice cover in the region, were instrumented to measure force in the normal and tangential directions. The distribution of normal forces along the boundary was compared with as distribution derived by using a theoretical model. An ice control structure (ICS) was installed in the basin and experiments were conducted to measure the forces on the ICS and the ice release through the opening in the ICS during simulated ship passages. The experimental results are presented in a nondimensional form. In addition, the force per unit length on the ICS and the area of ice released through its opening were estimated for the expected wind conditions at the Port Huron site.
    Type of Medium: Series available for loan
    Pages: v, 27 Seiten , Illustrationen
    Series Statement: CRREL Report 82-9
    Language: English
    Note: CONTENTS Abstract Preface List of symbols Introduction Theoretical models Case 1 Case 2 Case 3 Experimental program Experimental facility Scaling factors Experimental results Analysis of wind data for lower Lake Huron Summary and conclusions Release of ice through the opening of an ICS Ice forces on the ice control structure Ice forces on ice control structure from a large unconsolidated ice cover Literature cited Appendix A. Equation for the stress resultants and velocities of the ice cover Appendix B. Monthly summary of wind data at Port Huron
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  • 4
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-79/8
    In: CRREL Report, 79-8
    Description / Table of Contents: Sea ice ridging statistics obtained from a series of laser surface roughnessprofiles are examined. Each set of profiles consists of six 200-km-long flight tracks oriented approximately perpendicular to the coastline of the Chukchi and Beaufort Seas. The landward ends of the profiles were located at Point Lay, Wainwright, Barrow, Lonely, Cross Island and Barter Island. The flights were made in February, April, August, and December 1976, and one additional profile was obtained north of Cross Island during March 1978. It was found that although there is a systematic variation in mean ridge height (h) with season (with the highest values occurring in late winter), there is no systematic spatial variation in h at a given time. The number of ridges/km (micron) is also high during the late winter, with the highest values occurring in the Barter and Cross Island profiles . In most profiles, the ice 20 to 60 km from the coast is more highly deformed (higher micron values) than the ice either nearer the coast or farther seaward. The Wadhams model for the distribution of ridge heights gives better agreement with observed values in the higher ridge categories than does the Hibler model. Estimates of the spatial recurrence frequency of large pressure ridges are made by using the Wadhams model and also by using an extreme value approach. In the latter, the distribution of the lagest ridges per 20 km of laser track was found to be essentially normal
    Type of Medium: Series available for loan
    Pages: iv, 28 Seiten , Illustrationen
    Series Statement: CRREL Report 79-8
    Language: English
    Note: CONTENTS Abstract Preface Introduction Data collection and processing Analysis General Variations in ridging Ridge height distributions Occurrence of high ridges The tail of the distribution Extreme values Applications to offshore design Conclusions Literature cited Appendix A. Tabulated ice ridge data
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  • 5
    Call number: ZSP-201-76/18
    In: CRREL Report, 76-18
    Description / Table of Contents: Three surface elevation and ice thickness profiles obtained during the 1972 Arctic Ice Dynamics Joint Experiment on a multiyear ice floe were analyzed to obtain relationships between surface elevation, thickness and physical properties of the ice. It was found that for ice freeboards from 0.10 m to 1.05 m above sea level a linear relationship between ice density and freeboard could be postulated. The equation for the regression line is: Ice density = -194f' + 974 kg/cu m where f' is the ice freeboard plus snow depth in ice equivalent at the point in question. This statistical relationship is consistent with observed physical properties, which indicate that as the ice freeboard increases, ice salinity decreases and the higher freeboard or thicker ice therefore decreases in density. Using this variable density with freeboard relationship, a model was constructed to predict ice thickness, given ice freeboard and snow depth alone. This prediction is desirable, since snow depth and freeboard are relatively easy to obtain, whereas ice thickness can usually be obtained only by drilling through the ice. The model was compared with two other models. It was found that the variable density prediction model gave the best approximation to observed ice thickness, with a standard error between the measured and predicted value of about 0.4 m, compared with errors from 50 to 100% higher for the other two models.
    Type of Medium: Series available for loan
    Pages: v, 25 Seiten , Illustrationen
    Series Statement: CRREL Report 76-18
    Language: English
    Note: Contents Abstract Preface Summary Introduction Previous work Results Models for predicting thickness from ice freeboard Comparison between measured and predicted thicknesses Spectral behavior of measured and predicted profiles Comparisons of ice thickness using airborne laser profilometry Conclusions Literature cited Appendix A: Misgivings on isostatic imbalance as a mechanism for sea ice cracking
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  • 6
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-202-314
    In: Research report
    Description / Table of Contents: CONTENTS: Introduction. - Previous work. - Sea ice terrain model. - Traffic ability model. - Analytic calculation of DT/DSL. - Monte Carlo calculation. - Results of traffic ability computations. - Experimental traffic ability ratios using ridge overlays. - Regional variations in ridging intensity. - Additional traffic ability aspects of sea ice. - Shear zone and rubble fields. - Linear lead systems. - Conclusions. - Literature cited. - Appendix A. Distribution of the lateral extent of ridges. - Abstract.
    Description / Table of Contents: A sea ice terrain model, based upon previously tested height and spacing distributions for sea ice pressure ridging, is developed. Using this model, and additional information on pressure ridge extents, a trafficability model for vehicles traversing the pack ice is developed. Both analytic and Monte Carlo calculations of vehicle trafficability, measured in terms of the average ratio of the total distance traveled over a straight-line distance, are performed. The calculations include cul-de-sacs due to ridge intersections. The trafficability ratio is given as a function of ridge-height-clearance ability of the vehicle and of ridging parameters which may be obtained from laser profiles of the arctic pack ice. Results are in good agreement with simulated routes through sea ice terrain taken from aerial photo mosaics. Contour plots of ridging parameters taken from laser profilometry are also supplied. These plots, together with the trafficability model, supply mobility information for the whole of the western portion of the Arctic Basin.
    Type of Medium: Series available for loan
    Pages: iii, 21 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory, CRREL, US Army Material Command 314
    Language: English
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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-201-78/15
    In: CRREL Report, 78-15
    Description / Table of Contents: This report first discusses the general approach for calculating the horizontal forces an ice cover exerts on a structure. Ice force determination consists of two parts: (1) the analysis of the in-plane forces assuming that the ice cover remains intact and (2) the use of a failure criterion, since an ice force cannot be larger than the force capable of breaking up the ice cover. For an estimate of the largest ice force, an elastic plate analysis and a failure criterion are often sufficient. A review of the literature revealed that, in the majority of the analyses, it is assumed that the failure load is directly related to a 'crushing strength' of the ice cover. However, observations in the field and tests in the laboratory show that in some instances the ice cover fails by buckling. This report reviews the ice force analyses based on the buckling failure mechanism and points out their shortcomings. The report then presents a new method of analysis which is based on the buckling mechanism
    Type of Medium: Series available for loan
    Pages: iv, 13 Seiten , Illustrationen
    Series Statement: CRREL Report 78-15
    Language: English
    Note: CONTENTS Abstract Preface Introduction and statement of problem Review of relevant analyses and tests Determination of the largest ice force on an isolated structure Preliminary remarks The buckling analysis of a floating wedge Proposed method to determine 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-201-79/12
    In: CRREL Report, 79-12
    Description / Table of Contents: An analysis of a point source bubbler system used to induce local melting of an ice cover is presented. The analysis leads to a numerical simulation programmed in FORTRAN which may be used to predict the effectiveness of such systems. An example application is presented using a typical record of average daily air temperatures. The FORTRAN program for the point source simulation as well as a FORTRAN program for line source systems are included in the Appendix.
    Type of Medium: Series available for loan
    Pages: iii, 12 Seiten , Illustrationen
    Series Statement: CRREL Report 79-12
    Language: English
    Note: CONTENTS Abstract Preface Introduction Outline of analysis Plume analysis Heat transfer analysis Temperature of impinging plume Heat transfer coefficient Melting of the ice cover Simulation example Thermal reserve analysis Literature cited Appendix
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  • 9
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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    Call number: ZSP-201-79/19
    In: CRREL Report, 79-19
    Description / Table of Contents: The critical velocities of loads moving over floating ice plates have been determined by several authors. In all these analyses it was assumed that the in-plane force field in the ice cover is zero. However, due to constrained thermal strains, in-plane forces do occur in the field. The purpose of the present paper is to determine their effect upon the critical velocities of the moving loads. It is shown that a uniform compression force field reduces the critical velocity, whereas a tension force field has the opposite effect.
    Type of Medium: Series available for loan
    Pages: ii, 12 Seiten , Illustrationen
    Series Statement: CRREL Report 79-19
    Language: English
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  • 10
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    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
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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.
    Type of Medium: Series available for loan
    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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