ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 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-201-78/2
    In: CRREL Report, 78-2
    Description / Table of Contents: Many of the technical questions relating to iceberg transport are given brief, but quantitative, consideration. These include iceberg genesis and properties, the mechanical stability of icebergs at sea, towing forces and tug characteristics, drag coefficients, ablation rates, and handling and processing the iceberg at both the pick-up site and at the final destination. In particular the paper attempts to make technical information on glaciological and ice engineering aspects of the problem more readily available to the interested planner or engineer. Specific conclusions include: (1) No unprotected iceberg, no matter how long or wide, would be likely to survive the ablation caused by a long trip to low latitudes. (2) Icebergs that have a horizontal dimension exceeding 2 km may well be prone to breakup by long wavelength swells. (3) To avoid the dangers associated with an iceberg capsizing, the width of a 200-m thick iceberg should always be more than 300 m. (4) For towing efficiency the length/width ratio of a towed iceberg should be appreciably greater than unity. (5) For a pilot project, the selected iceberg would have to be quite small, if for no other reason than the practical availability of tug power.
    Type of Medium: Series available for loan
    Pages: v, 31 Seiten , Illustrationen
    Series Statement: CRREL Report 78-2
    Language: English
    Note: CONTENTS Abstract Preface Introduction Sources and properties of tabular icebergs Sources Characteristics of ice shelves near the ice front Characteristics of tabular icebergs Towing Geophysical and engineering considerations Tug characteristics Handling and processing Cutting and boring with thermal devices Penetration with electrothermal devices Electrothermal cutting Making vertical cuts by pre-split blasting Primary fragmentation by blasting Primary fragmentation by mechanical sawing Comminuting ice with machines Slurry pipelines Conclusion Literature cited
    Location: AWI Archive
    Branch Library: AWI Library
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 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-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
    Location: AWI Archive
    Branch Library: AWI Library
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-201-78/13
    In: CRREL Report, 78-13
    Description / Table of Contents: Field observations of the growth fabrics of the fast and near-fast ice along the coasts of the Beaufort and Chukchi Seas show that, at depths of more than 60 cm below the upper ice surface, the sea ice crystals show striking alignments within the horizontal plane. At one site this alignment was well developed at a depth of 15 cm and in all cases the degree of preferred orientation increased with depth, with the strongest orientations occurring at the bottom of the ice sheet. In general the c-axes of the crystals were aligned roughly E-W parallel to the coast. In the vicinity of islands the alignment roughly paralleled the outlines of the islands and in narrow passes between islands the alignment paralleled the channel. Our observations, as well as similar observations made in the Kara Sea by Cherepanov, can be explained if it is assumed that the c-axes of the crystals are aligned parallel to the 'long-term' current direction at the sea ice/sea water interface. The alignments are believed to be the result of geometric selection among the growing crystals, with the most favored orientation being that in which the current flows normal to the (0001) plates of ice that make up the dendritic ice/water interface characteristics of sea ice. It is hypothesized that current flow in this direction reduces the thickness of the solute boundary layer as well as the salinity in the liquid at the interface. This lowered salinity allows crystals in the favored orientation to extend farther into the melt than neighboring crystals with less favored orientations. In addition the current tends to induce a continuous flux of supercooled seawater against the sides of the crystals that extend ahead of the interface.
    Type of Medium: Series available for loan
    Pages: v, 29 Seiten , Illustrationen
    Series Statement: CRREL Report 78-13
    Language: English
    Note: CONTENTS Abstract Preface Introduction Locale and techniques Observations Vertical variations in crystal orientation Regional variations in crystal orientation Summary of observations Causes Initial ice skim Earth’s magnetic field Currents Conclusions and consequences Literature cited
    Location: AWI Archive
    Branch Library: AWI Library
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Corps of Engineers, Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-202-276
    In: Research report
    Description / Table of Contents: CONTENTS: Introduction. - Test site. - Test procedures. - Equipment. - Unconfined compression tests. - Ring tensile tests. - Test results. - Unconfined compression tests. - Ring tensile tests. - Discussion. - Literature cited. - Appendix A. Calculation of the effect of nonaxial loading of unconfined compression specimens. - Appendix B. Camp Century unconfined compressive strength data at -25C. - Appendix C. Camp Century ring-tensile strength data at -25C. - Appendix D. Unconfined compressive strength of Camp Century vertical snow samples 8.25 in. length, 3.0 in. diam at -25C. - Abstract.
    Description / Table of Contents: The unconfined compressive strengths [Sigma]c and the ring-tensile strengths [Sigma]T of snow and ice specimens from the Inclined Drift at Camp Century, Greenland, were determined. The specimen densities varied over essentially the complete natural density range of polar snow and ice (0.340 to 0.890 g/cm^3). The specimens were loaded rapidly to failure with times varying between 0.2 and 1.4 sec. During loading, head speeds varied between 5.1 and 23.6 cm/min, although during individual tests they were constant. Even the low density specimens failed in the brittle mode. Although a plot of [Sigma]T vs [Gamma] is linear, [Sigma]c vs [Gamma] is clearly nonlinear. This nonlinearity may result from either changes in the level of the internal stress concentrations associated with the voids in the snow or from changes in the ratio (bulk porosity/effective porosity of the failure surface) with density. Both tangent and secant moduli are linear functions of [Gamma]. There is no pronounced change in [Sigma]c with changes in strain rate. A significant increase in [Sigma]T, [Sigma]c and the modulus values was noted at bulk densities greater than 0.830 g/cm^3. This increase is presumably caused by the close-off of the air passages.
    Type of Medium: Series available for loan
    Pages: 35 Seiten , Illustrationen, graphische Darstellungen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory, CRREL, US Army Material Command 276
    Language: English
    Branch Library: AWI Library
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Call number: SR 90.0001(1046-O)
    In: U.S. Geological Survey bulletin
    Type of Medium: Series available for loan
    Pages: IV S., S. 385-413 + 1 pl.
    Series Statement: U.S. Geological Survey bulletin 1046-O
    Language: English
    Location: Lower compact magazine
    Branch Library: GFZ Library
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Call number: 92-0099
    Branch Library: AWI Library
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 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-202-80
    In: Research report / Cold Regions Research and Engineering Laboratory, 80
    Description / Table of Contents: From the Introduction: During the last few years, there has been an increased interest in developing a rational explanation for the rather considerable variation in such bulk properties of sea ice as its strength, density, thermal conductivity, latent heat of melting, and coefficient of thermal expansion. Of these properties, sea-ice strength has received by far the most attention for practical reasons.
    Type of Medium: Series available for loan
    Pages: iv, 30, A6, B10, C2, D5 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 80
    Language: English
    Note: CONTENTS Preface Summary Introduction Experimentation Method of growing salt ice Strength test procedures Bulk properties of salt ice Phase relations Density and air content Strength results Strength of fresh-water ice Strength of NaCl ice as a function of brine volume Strength of NaCl· 2H2O ice as a function of the relative volume of solid salt Effect of thermal history on salt-ice strength Phase hysteresis Geometric hysteresis Effect of short-term cooling on the strength of fresh-water and NaCl·2H2O ice Effect of the volume of inclosed air on the strength of salt ice Conclusions NaCl ice Sea ice References Appendix A: Volume of brine and NaCl· 2H2O in NaCl ice as a function of salinity and temperature Appendix B: Ring test results Normal test sequences Appendix C: Ring test results Hysteresis test sequences Appendix .b: Ring test results Thermal history test sequences
    Location: AWI Archive
    Branch Library: AWI Library
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 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
    Location: AWI Reading room
    Branch Library: AWI Library
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Series available for loan
    Series available for loan
    Hanover, NH : U.S. Army Cold Regions Research and Engineering Laboratory
    Associated volumes
    Call number: ZSP-202-117
    In: Research report / Cold Regions Research and Engineering Laboratory, 117
    Description / Table of Contents: Summary: An experiment was designed to investigate operator-variance in the determination of the plastic limit of cohesive soils, independent of sample preparation and hydration time. A standard sample was prepared by dry-mixing commercial clay, "Grundite", with a pure silt. After the sample was hydrated for 3 weeks, five random samples were taken and five replicates performed on each sample. Analysis of variance (AOV) shows that there is no reason to doubt that the sample is homogeneous at the 0.05 level of significance. Random samples were then distributed to five zones of operators, where a zone is defined as a group of operators with similar backgrounds and engineering interests. Two operators from each group performed five replicates. The AOV model used in the analysis is mixed with the upper level fixed and the two lower levels random. The estimated "within" and "between" operator variances are 0. 45 and 4. 18 respectively. The estimated "between zones" contribution to the total sum of squares is negative. No correlation was found between an operator's internal variance and his deviation from the grand mean. On the basis of this experiment, no reason-exists to doubt that an "untrained" operator can obtain results comparable to those of professional operators. The major factor contributing to the total sample variance is the inconsistency between the individual operators who, although able to duplicate their own determinations, do not call the same end point. To minimize between operator variance, a readily prepared standard sample is suggested with which any operator can calibrate his plastic limit determinations against the expected national average.
    Type of Medium: Series available for loan
    Pages: iv, 8 Seiten , Illustrationen
    Series Statement: Research report / Cold Regions Research and Engineering Laboratory 117
    Language: English
    Note: CONTENTS Preface Summary ­Introduction Sample preparation Sample homogeneity Distribution of samples Analysis Conclusions and suggested standardization References
    Location: AWI Archive
    Branch Library: AWI Library
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Call number: ZSP-201-83/21
    In: CRREL Report, 83-21
    Description / Table of Contents: The probability density function of the gouge depths into the sediment is represented by a simple negative exponential over four decades of gouge frequency. The exceedance probability function is, therefore, e to the -lambda d, where d is the gouge depth in meters and lambda is a constant. The value of lambda shows a general decrease with increasing water depth, from 9/m in shallow water to less than 3/m in water 30 to 35 m deep. The deepest gouge observed was 3.6 m, from a sample of 20,354 gouges that have depths greater than or equal to 0.2 m. The dominant gouge orientations are usually unimodal and reasonably clustered, with the most frequent alignments roughly parallel to the general trend to the coastline. The value of N(bar) sub 1, the mean number of gouges (deeper than 0.2 m) per kilometer measured normal to the trend of the gouges, varies from 0.2 for protected lagoons to 80 in water between 20 and 38 m deep in unprotected offshore regions. The distribution of the spacings between gouges as measured along a sampling track is a negative exponential. The form of the frequency distribution of N sub 1 varies with water depth and is exponential for lagoons and shallow offshore areas, previously skewed for 10 to 20 m depths off the barrier islands, and near-normal for deeper water. As a Poisson distribution gives a reasonable fit to the N sub 1 distributions for all water depths, it is suggested that gouging can be taken as approximating a Poisson process in both space and time. The distributions of the largest values per kilometer of gouge depths, gouge widths, and the heights of the lateral embankment of sediments plowed from the gouges are also investigated.
    Type of Medium: Series available for loan
    Pages: 40 Seiten , Illustrationen, 1 Karte
    Series Statement: CRREL Report 83-21
    Language: English
    Note: CONTENTS Abstract Preface Introduction Background and environmental setting Data collection and terminology Data analysis Gouge depths Gouge orientation Gouge frequency Extreme value analysis Applications to offshore design Gouge depth Extreme value statistics Burial depths Conclusion Literature cited Appendix A: Detailed bathymetric map of the Alaskan portion of the Beaufort Sea
    Location: AWI Archive
    Branch Library: AWI Library
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...