scholarly journals A Comparison of Ice Fabrics and Textures at Camp Century, Greenland and Byrd Station, Antarctica

1982 ◽  
Vol 3 ◽  
pp. 118-124 ◽  
Author(s):  
Susan L. Herron ◽  
Chester C. Langway
Keyword(s):  
Short Interval ◽  
Ice Cores ◽  
Remarkable Similarity ◽  
Single Maximum ◽  
Crystal Orientations ◽  
Degree Of Orientation ◽  
Break Up ◽  
Ice Fabrics ◽  
High Degree

A comparison of the crystalline texture and fabric of the two deep cores to bedrock from Camp Century, Greenland, and Byrd station, Antarctica, reveals striking similarities. Each core exhibits a fabric profile which progresses from depositional fabrics at shallow depths through multi-maxima transitional stages into single maximum distributions. The major difference between the two cores occurs near the base where the Camp Century fabrics maintain a high degree of orientation while the Byrd station fabrics break up into a diamond pattern. The most remarkable similarity between the two profiles occurs at the glacial-interglacial transition where crystal sizes decrease and crystal orientations strengthen significantly over a very short interval. Similar changes occur in other deep ice cores, thus indicating the possibility that the late Wisconsin ice has a unique crystallographic signature.

scholarly journals A Comparison of Ice Fabrics and Textures at Camp Century, Greenland and Byrd Station, Antarctica

1982 ◽  
Vol 3 ◽  
pp. 118-124 ◽  
Author(s):  
Susan L. Herron ◽  
Chester C. Langway
Keyword(s):  
Short Interval ◽  
Ice Cores ◽  
Remarkable Similarity ◽  
Single Maximum ◽  
Crystal Orientations ◽  
Degree Of Orientation ◽  
Break Up ◽  
Ice Fabrics ◽  
High Degree

A comparison of the crystalline texture and fabric of the two deep cores to bedrock from Camp Century, Greenland, and Byrd station, Antarctica, reveals striking similarities. Each core exhibits a fabric profile which progresses from depositional fabrics at shallow depths through multi-maxima transitional stages into single maximum distributions. The major difference between the two cores occurs near the base where the Camp Century fabrics maintain a high degree of orientation while the Byrd station fabrics break up into a diamond pattern. The most remarkable similarity between the two profiles occurs at the glacial-interglacial transition where crystal sizes decrease and crystal orientations strengthen significantly over a very short interval. Similar changes occur in other deep ice cores, thus indicating the possibility that the late Wisconsin ice has a unique crystallographic signature.

scholarly journals Social Roles as Viewed by Speakers of Non-Cognate Languages.

2020 ◽  
Vol 3 (4) ◽  
pp. 71-83
Author(s):  
Olga Leonidovna Byessonova ◽  
◽  
Keyword(s):  
Native Speakers ◽  
Social Roles ◽  
Men And Women ◽  
Professional Activities ◽  
Male Roles ◽  
The Family ◽  
Degree Of Orientation ◽  
Native Speakers Of English ◽  
The Public Sphere ◽  
High Degree

Introduction. The article addresses the reflection of ideas about gender social roles in the conceptual and linguistic worldview of men and women. Materials and methods. The analysis is based on the material of the linguistic experi-ment conducted with native speakers of such English and Ukrainian. Results. The results of the experiment reveal the differences in the perception by the native speakers of English and Ukrainian of gender social roles. As the analysis of the material shows, in the Ukrainian society, the public sphere is associated to a greater de-gree with the professional activities of men and women, and there is a high degree of orientation of women towards motherhood. In English, outside the family, mainly male roles are defined, and the roles of women are mainly family and are in the sphere of personal, emotional ties. Discussion and Conclusions. The analysis of social roles shows that the Ukrainian lin-guistic community, to a greater extent than the English-speaking, is characterized by an orientation towards the traditional patriarchal family, in which a woman is the keeper of the hearth, the organizer of male consumption, and the man is the owner and head of the family. The results obtained in the course of the experiment enable to establish a systemic cor-relation between the language structure and the social structure, to establish correla-tions between the language phenomena and the gender of the communicants.

scholarly journals The orientation of iron–sulphur clusters in membrane multilayers prepared from aerobically-grown Escherichia coli K12 and a cytochrome-deficient mutant

1980 ◽  
Vol 190 (2) ◽  
pp. 385-393 ◽  
Author(s):  
Haywood Blum ◽  
Robert K. Poole ◽  
Tomoko Ohnishi
Keyword(s):  
Magnetic Field ◽  
Escherichia Coli ◽  
Cytoplasmic Membrane ◽  
Deficient Mutant ◽  
E Coli ◽  
Membrane Particles ◽  
Degree Of Orientation ◽  
High Degree ◽  
Cytochrome Content ◽  
The Magnetic Field

1. Membrane particles prepared from ultrasonically-disrupted, aerobically-grown Escherichia coli were centrifuged on to a plastic film that was supported perpendicular to the centrifugal field to yield oriented membrane multilayers. In such preparations, there is a high degree of orientation of the planes of the membranes such that they lie parallel to each other and to the supporting film. 2. When dithionite- or succinate-reduced multilayers are rotated in the magnetic field of an e.p.r. spectrometer, about an axis lying in the membrane plane, angular-dependent signals from an iron–sulphur cluster at gx=1.92, gy=1.93 and gz=2.02 are seen. The g=1.93 signal has maximal amplitude when the plane of the multilayer is perpendicular to the magnetic field. Conversely, the g=2.02 signal is maximal when the plane of the multilayer is parallel with the magnetic field. 3. Computer simulations of the experimental data show that the cluster lies in the cytoplasmic membrane with the gy axis perpendicular to the membrane plane and with the gx and gz axes lying in the membrane plane. 4. In partially-oxidized multilayers, a signal resembling the mitochondrial high-potential iron–sulphur protein (Hipip) is seen whose gz=2.02 axis may be deduced as lying perpendicular to the membrane plane. 5. Appropriate choice of sample temperature and receiver gain reveals two further signals in partially-reduced multilayers: a g=2.09 signal arises from a cluster with its gz axis in the membrane plane, whereas a g=2.04 signal is from a cluster with the gz axis lying along the membrane normal. 6. Membrane particles from a glucose-grown, haem-deficient mutant contain dramatically-lowered levels of cytochromes and exhibit, in addition to the iron–sulphur clusters seen in the parental strain, a major signal at g=1.90. 7. Only the latter may be demonstrated to be oriented in multilayer preparations from the mutant. 8. Comparisons are drawn between the orientations of the iron–sulphur proteins in the cytoplasmic membrane of E. coli and those in mitochondrial membranes. The effects of diminished cytochrome content on the properties of the iron–sulphur proteins are discussed.

scholarly journals Late Quaternary Rock Glaciers, Mount Kenya, Kenya

1980 ◽  
Vol 25 (93) ◽  
pp. 492-497 ◽  
Author(s):  
W. C. Mahaney
Keyword(s):  
Late Quaternary ◽  
Short Interval ◽  
Morphological Characteristics ◽  
Ice Cores ◽  
Rock Glacier ◽  
Glacier Surface ◽  
Side Rock ◽  
Differential Movement ◽  
Probable Presence ◽  
Rock Glaciers

AbstractRock glaciers in Teleki Valley on Mount Kenya exist above 4 000 m below steep valley walls where they are supplied with debris from avalanche couloirs. These valley-side rock glaciers consist of three or four lobes of rubble bounded by transverse furrows resulting from differential movement. No ice cores were observed in these rubble sheets, but “drunken forest” stands of Senecio keniodendron indicate the probable presence of interstitial ice resulting either from the metamorphism of snow buried under rockfall and slide-rock debris, or from freezing of water beneath the rock mantle. A geological survey of Mount Kenya in 1976 revealed that rock glaciers are anomalous in the Mount Kenya Afroalpine zone above 3 300 m. Analysis of weathering rinds indicates that several rock-glacier lobes were built up over a short interval of time at or near the end of the last glacial maximum (Würm). Oversteepened fronts on the westernmost lobes may have resulted from re-activation coinciding with the advance of glaciers during late Holocene time (<1 000 B.P.). Soils mantle 20% of the rock-glacier surface and have morphological characteristics comparable with soils forming on moraines of late Würm age in upper Teleki, Hausberg, and Mackinder Valleys.

scholarly journals Ice Fabrics and Petrography, Meserve Glacier, Antarctica

1974 ◽  
Vol 13 (68) ◽  
pp. 285-306 ◽  
Author(s):  
P.W. Anderton
Keyword(s):  
Steady State ◽  
Stress Level ◽  
Optic Axis ◽  
Near Surface ◽  
Fine Grained ◽  
Basal Ice ◽  
Single Maximum ◽  
Fabric Analysis ◽  
Rock Interface ◽  
Ice Fabrics

Results of petrographic and fabric analysis of fine-grained cold ice from the tongue of Meserve Glacier, Antarctica, are described. Most of the basal ice is remarkably uniform in texture and shows an optic-axis fabric with a single strong maximum, which is consistent with the steady-state conditions of flow. Within 0.5 m of the ice–rock interface, irregularities in the bed cause flow perturbations which are correlated with recrystallization and changes in fabric of the ice. Optic-axis fabrics in the basal ice show close symmetry relationships with dimensional fabric and deformation symmetry. Grain-size of the ice increases towards the surface of the glacier and the single maximum of the optic-axis fabric undergoes a rotation about the flow vector. In the near surface, where strain-rates are relatively much lower, the optic-axis fabric symmetry is not closely related to either deformation symmetry or the dimensional fabric. Syntectonic recrystallization of ice throughout the glacier tongue characteristically produces a strong single-maximum fabric, the orientation of which in relation to the stress field is apparently determined by stress level. Under steady-state conditions of flow, the strength of the maximum also appears to be a function of stress level.

scholarly journals Structural characteristics of congelation and platelet ice and their role in the development of antarctic land-fast sea ice

1993 ◽  
Vol 39 (132) ◽  
pp. 223-238 ◽  
Author(s):  
M. O. Jeffries ◽  
W. F. Weeks ◽  
R. Shaw ◽  
K. Morris
Keyword(s):  
Growth Rates ◽  
Ice Cores ◽  
Current Control ◽  
Water Current ◽  
Minor Amount ◽  
Mcmurdo Sound ◽  
Ice Growth ◽  
Fast Ice ◽  
Ice Fabrics ◽  
Platelet Ice

AbstractIce cores were obtained in January 1990 from the land-fast ice in McMurdo Sound for a study of variations in texture, fabric, sub-structure, composition and development. Two primary ice types were observed, congelation and platelet, with a minor amount of frazil ice. Congelation ice growth precedes platelet-ice accretion. Congelation-ice fabrics show frequent moderate to strong alignments, a phenomenon believed to be due to water-current control of selective ice-crystal growth. Platelet ice originates at the base of the congelation ice, initially as a porous latticework of tabular ice crystals which subsequently consolidate by congelation of the interstitial water. Interstitial congelation-ice fabrics generally have little or no alignment, indicating the reduced effect of currents within the platelet latticework prior to solidification. Platelet-crystal textures range from small, wavy-edged forms to large, blade-like forms. Platelet-crystal fabrics indicate that, in addition to being randomly oriented, the platelet latticeworks commonly include many crystals with their flat (0001) faces oriented both parallel and normal to the base of the overlying ice. Plate-width data suggest that the interstitial congelation ice-growth rates remain similar to those of the overlying congelation ice. This effective increase in growth rates probably happens because the latticework of accumulating platelets ahead of the freezing interface ensures that the water within the platelet layer is at the freezing point and less heat has to be removed from platelet-rich water than from platelet-free water for a given thickness of congelation ice to grow. The negative oceanic heat flux associated with platelet-ice formation in McMurdo Sound explains why McMurdo Sound fast ice is thicker than Ross Sea pack ice, and also why it reaches a greater thickness than Arctic fast ice grown in a similar polar marine climate. Plate widths in the McMurdo Sound congelation ice suggest, however, that it grows no faster than Arctic congelation ice.

Anisotropy in Thermal, Electrical and Mechanical Properties of Spin-Coated Polymer Dielectrics

1994 ◽  
Vol 338 ◽  
Author(s):  
Sue Ann Bidstrup ◽  
Thomas C. Hodge ◽  
Linda Lin ◽  
Paul A. Kohl ◽  
J.B. Lee ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Three Dimensional ◽  
Interlayer Dielectrics ◽  
Polymer Dielectrics ◽  
Degree Of Orientation ◽  
High Degree ◽  
Interconnection Structure

ABSTRACTIn MCM-D applications, interlayer dielectrics separate and insulate metal conductors to form a three-dimensional interconnection structure. Due to the three-dimensional nature of these structures, the thermal, electrical and mechanical properties of the dielectricmaterials must be known for all orientations in order to correctly design and simulate devices. The most commonly used polymer in microelectronics, polyimide, exists in formulations which have been shown to have a high degree of orientation and exhibit anisotropicproperties.

scholarly journals Orientation Mapping of Extruded Polymeric Composites by Polarized Micro-Raman Spectroscopy

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Xiaoyun Chen ◽  
M. Anne Leugers ◽  
Tim Kirch ◽  
Jamie Stanley
Keyword(s):  
Raman Spectroscopy ◽  
Molecular Orientation ◽  
Polymeric Composite ◽  
Surface Region ◽  
Process Conditions ◽  
Entire Cross Section ◽  
Micro Raman Spectroscopy ◽  
Orientation Mapping ◽  
Degree Of Orientation ◽  
High Degree

Molecular orientation has a strong influence on polymeric composite materials’ mechanical properties. In this paper we describe the use of polarized micro-Raman spectroscopy as a powerful tool to map out the molecular orientation of a uniaxially oriented polypropylene- (PP-) based composite material. Initial samples exhibited a high degree of surface fibrillation upon cutting. Raman spectroscopy was used to characterize the degree of orientation in the skin and guide the development of the posttreatment process to optimize the skin relaxation while maintaining the high degree of orientation in the rest of the board. The PP oriented polymer composite (OPC) was oriented through an extrusion process and its surface was then treated to achieve relaxation. Micro-Raman analysis at the surface region demonstrated the surface orientation relaxation, and the results provide an effective way to correlate the extent of relaxation and process conditions. Larger scale orientation mapping was also carried out over the entire cross-section (12.7 cm × 2.54 cm). The results agree well with prior expectation of the molecular orientation based on the extrusion and subsequent quenching process. The methodologies described here can be readily applied to other polymeric systems.

Excitation and inhibition in orientation selectivity of cat visual cortex neurons revealed by whole-cell recordings in vivo

1993 ◽  
Vol 10 (6) ◽  
pp. 1151-1155 ◽  
Author(s):  
M. Volgushev ◽  
Xing Pei ◽  
T. R. Vidyasagar ◽  
O. D. Creutzfeldt
Keyword(s):  
Striate Cortex ◽  
Cortical Cell ◽  
Orientation Selectivity ◽  
Cortical Cells ◽  
Whole Cell ◽  
Degree Of Orientation ◽  
Visual Cortex Neurons ◽  
High Degree ◽  
Whole Cell Recordings

AbstractOne striking transformation in response properties that occurs in the geniculo-cortical pathway is the appearance of a high degree of orientation selectivity in the cortex. This property may be conceived as arising purely from the excitatory inputs to the cell, as being structured largely by the inhibition a cortical cell receives or could be due to a combination of the two. We have studied the contributions of excitatory and inhibitory inputs to cortical cells' orientation selectivity by analyzing the postsynaptic potentials evoked in cat striate neurones by flashing stimuli of different orientations. We made these recordings using the in vivo whole-cell technique (Xing Pei et al., 1991), which provides more stable and reliable results than classical intracellular recording methods. Our results show that the cat striate cortex exhibits a variety of mechanisms to achieve orientation selectivity. Orientation selectivity of a particular cell can be created by excitatory, by inhibitory, or by a combination of both mechanisms.

scholarly journals Fabric measurement along the NEEM ice core, Greenland, and comparison with GRIP and NGRIP ice cores

2014 ◽  
Vol 8 (1) ◽  
pp. 307-335 ◽  
Author(s):  
M. Montagnat ◽  
N. Azuma ◽  
D. Dahl-Jensen ◽  
J. Eichler ◽  
S. Fujita ◽  
...  
Keyword(s):  
Ice Core ◽  
Ice Cores ◽  
Deformation Pattern ◽  
Bottom Part ◽  
Single Maximum ◽  
Shear Component ◽  
Climatic Transition ◽  
The Difference ◽  
The Impact ◽  
Good Agreement

Abstract. Fabric (distribution of crystallographic orientations) profile along the full NEEM ice core, Greenland, is presented in this work. Data were measured in the field by an Automatic Ice Texture Analyzer every 10 m, from 33 m down to 2461 m depth. The fabric evolves from a slightly anisotropic fabric at the top, toward a strong single maximum at about 2300 m, which is typical of a deformation pattern mostly driven by uniaxial compression and simple shearing. A sharp increase in the fabric strengthening is observed at the Holocene to Wisconsin climatic transition. A similar strengthening, toward an anisotropic single maximum-type fabric, has been observed in several ice cores from Greenland and Antarctica, and can be attributed to a positive feedback between changes in ice viscosity at the climatic transition, and the impact of a shear component of stress. Centimeter scale abrupt texture (fabric and microstructure) variations are observed in the bottom part of the core. Their positions are in good agreement with the folding hypothesis used for a climatic reconstruction by Dahl-Jensen et al. (2013). Comparison is made to two others ice cores drilled along the same ridge; the GRIP ice core drilled at the summit of the ice sheet, and the NorthGRIP ice core, drilled 325 km to the NNW of the summit along the ridge, and 365 km upstream from NEEM. The fabric profile clearly reflects the increase in shear deformation when moving NW along the ridge from GRIP to NorthGRIP and NEEM. The difference in fabric profiles between NEEM and NorthGRIP also evidences a stronger lateral extension associated with a sharper ridge at NorthGRIP.

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