scholarly journals Ice-covered ponds in the Untersee Oasis (East Antarctica): Distribution, chemical composition, and trajectory under a warming climate

2021 ◽  
Vol 53 (1) ◽  
pp. 324-339
Author(s):  
Benoit Faucher ◽  
Denis Lacelle ◽  
Nicole B. Marsh ◽  
David A. Fisher ◽  
Dale T. Andersen
Keyword(s):  
Chemical Composition ◽  
East Antarctica ◽  
Warming Climate

Chemical Composition, U–Th–Pb Age, and Geodynamic Setting of Metavolcanic Filla Series (Rauer Islands, East Antarctica)

Geotectonics ◽  
2020 ◽  
Vol 54 (3) ◽  
pp. 285-307
Author(s):  
E. V. Mikhalsky ◽  
N. L. Alexeev ◽  
I. A. Kamenev ◽  
A. N. Larionov ◽  
M. A. Gogolev ◽  
...  
Keyword(s):  
Chemical Composition ◽  
East Antarctica ◽  
Geodynamic Setting

Low-grade Sandow Group metasediments of the Denman Glacier area (East Antarctica): Chemical composition, age and provenance from U–Pb detrital zircon data, with some palaeotectonic implications

Polar Science ◽  
2020 ◽  
Vol 26 ◽  
pp. 100587
Author(s):  
E.V. Mikhalsky ◽  
D.A. Tkacheva ◽  
S.G. Skublov ◽  
G.L. Leitchenkov ◽  
N.V. Rodionov ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Detrital Zircon ◽  
East Antarctica ◽  
Low Grade ◽  
Glacier Area

scholarly journals CHEMICAL COMPOSITION CHANGE OF SUBSURFACE SNOW IN EAST ANTARCTICA WITH DISTANCE FROM THE COAST

2015 ◽  
Vol 52 (4) ◽  
pp. 129 ◽  
Author(s):  
L. P. Golobokova ◽  
T. V. Hodzher ◽  
Yu. A. Shibaev ◽  
V. A. Lipenkov ◽  
J.-R. Petit
Keyword(s):  
Chemical Composition ◽  
East Antarctica ◽  
Composition Change

scholarly journals Chemical composition of aerosol in the atmospheric surface layer of the East Antarctica coastal zone

2016 ◽  
Vol 56 (2) ◽  
pp. 177-188 ◽  
Author(s):  
L. P. Golobokova ◽  
V. V. Polkin ◽  
N. A. Onischuk ◽  
O. I. Khuriganova ◽  
A. B. Tikhomirov ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Coastal Zone ◽  
Atmospheric Aerosols ◽  
Enrichment Factors ◽  
East Antarctica ◽  
Chemical Components ◽  
Aerosol Composition ◽  
Wide Range ◽  
Fresh Snow ◽  
The Antarctic

Chemical composition of aerosol in the ground layer of the coastal zone in East Antarctica is analyzed in the article. The aerosol samples were taken in 2006–2015 during seasonal works of the Russian Antarctic Expeditions (RAE), namely, these were 52nd–53rd, 55th, and 58th–60th expeditions. Samples were taken in the 200‑km band of the sea-shore zone along routes of the research vessels (REV) «Akademik Fedorov» and «Akademik Treshnikov» as well as on territories of the Russian stations Molodezhnaya and Mirny. Although the results obtained did show the wide range of the aerosol concentrations and a certain variability of their chemical composition, some common features of the variability were revealed. Thus, during the period from 2006 to 2014 a decrease of average values of the sums were noted. Spatially, a tendency of decreasing of the ion concentrations was found in the direction from the station Novolazarevskaya to the Molodezhnaya one, but the concentrations increased from the Molodezhnaya to the station Mirny. The sum of ions of the aerosol in the above mentioned coastal zone was, on the average, equal to 2.44 μg/m3, and it was larger than that on the territory of the Antarctic stations Molodezhnaya (0,29 μg/m3) and Mirny (0,50 ág / m3). The main part to the sum of the aerosol ions on the Antarctic stations was contributed by Na+, Ca2+, Cl−, SO4 2−. The main ions in aerosol composition in the coastal zone are ions Na+ and Cl−. The dominant contribution of the sea salt and SO4 2− can be traced in not only the composition of atmospheric aerosols, but also in the chemical composition of the fresh snow in the coastal areas of East Antarctica: at the Indian station Maitri, on the Larsemann Hills, and in a boring located in 55.3 km from the station Progress (K = 1.4÷6.1). It was noted that values of the coefficient of enrichment K of these ions decreases as someone moves from a shore to inland. Estimation of contributions of the continental and maritime factors to formation of the aerosol chemical composition revealed higher enrichment ratios for K+, Ca2+, SO4 2− (K = 3.6÷13.0). This reflects not only influence of the natural sources, but the intensity of human activities on the Antarctic continent as well. The elemental composition of solid aerosols was also analyzed. The largest concentrations were determined for Zn, Al and Fe. The ratio of concentration of the elements in both the soluble and insoluble phases of the aerosol showed that 84.1% of the total amount of the elements was contained in a water-insoluble state. Fractional relation between the element concentrations changed in different phases from 16 to 98%. High enrichment of the aerosol particles by Zn, Cu, Cr, Ba, Pb, Ni,Se, As, Cd (the enrichment factors = 27÷26 445) had been revealed. The content of dominant chemical components (Na+, Cl−, Zn, Fe), factors and coefficients of the element enrichment in the aerosols as well as in fresh snow of the coastal zone of East Antarctica are indicative of the identity of sources where their composition is formed.

scholarly journals Spatial-temporal dynamics of chemical composition of surface snow in East Antarctic along the transect Station Progress-Station Vostok

2013 ◽  
Vol 7 (3) ◽  
pp. 2007-2028
Author(s):  
T. V. Khodzher ◽  
L. P. Golobokova ◽  
Y. A. Shibaev ◽  
V. Y. Lipenkov ◽  
J. R. Petit
Keyword(s):  
Chemical Composition ◽  
Snow Cover ◽  
Temporal Dynamics ◽  
Temporal Variations ◽  
East Antarctica ◽  
Chemical Components ◽  
Antarctic Snow ◽  
Russian Antarctic Expedition ◽  
Continental Origin ◽  
Deep Distribution

Abstract. This paper presents data on chemical composition of the Antarctic snow sampled during the 53rd Russian Antarctic Expedition (RAE, 2008) along the first tractor traverse (TT) from Station Progress to Station Vostok (East Antarctica). Snow samples were obtained from the cores drilled at 55.3, 253, 337, 369, 403, 441, 480, 519, 560, 618, 819, and 1276 km from Station Progress. Data on horizontal and deep distribution of chemical components in the snow provide evidence of spatial and temporal variations of conditions for the snow cover formation along the transect under study. Sea salt was the main source for chemical composition of snow cover near the ice edge. Concentrations of marine-derived components decreased further inland. A hypothesis was put forward that some ions in the snow cover of the central part of East Antarctica were likely to be of continental origin. Elevated concentrations of sulphate ions of continental origin were recorded in some profiles of the transect at a depth of 130–150 cm which was attributed to buried signals of the Pinatubo volcano eruption (1991).

Spatial and temporal variability of snow chemical composition and accumulation rate at Talos Dome site (East Antarctica)

2016 ◽  
Vol 550 ◽  
pp. 418-430 ◽  
Author(s):  
Laura Caiazzo ◽  
Silvia Becagli ◽  
Daniele Frosini ◽  
Fabio Giardi ◽  
Mirko Severi ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Temporal Variability ◽  
Accumulation Rate ◽  
East Antarctica ◽  
Spatial And Temporal Variability

The Origin of the Moon

1962 ◽  
Vol 14 ◽  
pp. 149-155 ◽  
Author(s):  
E. L. Ruskol
Keyword(s):  
Chemical Composition ◽  
Solar System ◽  
The Moon ◽  
The Earth ◽  
The Difference ◽  
Origin Of The Moon

The difference between average densities of the Moon and Earth was interpreted in the preceding report by Professor H. Urey as indicating a difference in their chemical composition. Therefore, Urey assumes the Moon's formation to have taken place far away from the Earth, under conditions differing substantially from the conditions of Earth's formation. In such a case, the Earth should have captured the Moon. As is admitted by Professor Urey himself, such a capture is a very improbable event. In addition, an assumption that the “lunar” dimensions were representative of protoplanetary bodies in the entire solar system encounters great difficulties.

On the Inhomogeneity of Chemical Composition over the Surface of 21 Per

1976 ◽  
Vol 32 ◽  
pp. 343-349
Author(s):  
Yu.V. Glagolevsky ◽  
K.I. Kozlova ◽  
V.S. Lebedev ◽  
N.S. Polosukhina
Keyword(s):  
Chemical Composition ◽  
Spectral Line ◽  
Variable Star ◽  
Radial Velocities ◽  
Crimean Astrophysical Observatory ◽  
Line Intensities ◽  
Magnetic Variable

SummaryThe magnetic variable star 21 Per has been studied from 4 and 8 Å/mm spectra obtained with the 2.6 - meter reflector of the Crimean Astrophysical Observatory. Spectral line intensities (Wλ) and radial velocities (Vr) have been measured.

Structural Studies on Mitotic Spindle Fibres

1978 ◽  
Vol 36 (3) ◽  
pp. 615-626
Author(s):  
J.R. Mcintosh
Keyword(s):  
Chemical Composition ◽  
Mitotic Spindle ◽  
Structural Studies ◽  
Mitotic Apparatus ◽  
Chemical Studies ◽  
Medical Interest ◽  
Spindle Fibres

The mitotic apparatus is a structure of obvious biological and medical interest, but it has proved to be a difficult cellular machine to understand. The chemical composition of the spindle is only slightly elucidated, largely because of the difficulties in preparing useful isolates of the structure. Chemical studies of the mitotic spindle have been reviewed elsewhere (Mcintosh, 1977), and will not be discussed further here. One would think that structural studies on the mitotic apparatus (MA) in situ would be straightforward, but even with this approach there is some disagreement in the results obtained with various methods and by different investigators. In this paper I will review briefly the approaches which have been used in structural studies of the MA, pointing out the strengths and problems of each approach. I will summarize the principal findings of the different methods, and identify what seem to be fruitful avenues for further work.

Effects of 5-5'-Diphenyl-2-thiohydantoin (DPTH) and Thyroxine on the Ultrastructure and Chemical Composition of Rat Liver

1971 ◽  
Vol 29 ◽  
pp. 570-571
Author(s):  
E. A. Elfont ◽  
R. B. Tobin ◽  
D. G. Colton ◽  
M. A. Mehlman
Keyword(s):  
Chemical Composition ◽  
Rat Liver ◽  
Future Study ◽  
Mode Of Action ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Effective Inhibitor ◽  
Biochemical Effects ◽  
Glycerophosphate Dehydrogenase ◽  
Stimulation Of

Summary5,-5'-diphenyl-2-thiohydantoin (DPTH) is an effective inhibitor of thyroxine (T4) stimulation of α-glycerophosphate dehydrogenase in rat liver mitochondria. Because this finding indicated a possible tool for future study of the mode of action of thyroxine, the ultrastructural and biochemical effects of DPTH and/or thyroxine on rat liver mere investigated.Rats were fed either standard or DPTH (0.06%) diet for 30 days before T4 (250 ug/kg/day) was injected. Injection of T4 occurred daily for 10 days prior to sacrifice. After removal of the liver and kidneys, part of the tissue was frozen at -50°C for later biocheailcal analyses, while the rest was prefixed in buffered 3.5X glutaraldehyde (390 mOs) and post-fixed in buffered 1Z OsO4 (376 mOs). Tissues were embedded in Araldlte 502 and the sections examined in a Zeiss EM 9S.Hepatocytes from hyperthyroid rats (Fig. 2) demonstrated enlarged and more numerous mitochondria than those of controls (Fig. 1). Glycogen was almost totally absent from the cytoplasm of the T4-treated rats.

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