scholarly journals Analysis of permafrost effect on water exchange processes

2021 ◽  
Vol 44 (2) ◽  
pp. 184-190
Author(s):  
V. V. Shepelev
Keyword(s):  
Solid State ◽  
Active Layer ◽  
Natural Water ◽  
Water Exchange ◽  
Water Cycle ◽  
Climate Fluctuations ◽  
Individual Consideration ◽  
Water Saturated ◽  
Exchange Function

The article focuses on the importance of studying the water exchange role of the permafrost, which currently occupies a quarter of the Earth's land and is 1.5 km deep in some regions, as well as assessing the permafrost impact on the formation of surface and ground water resources and regime. First of all, the permafrost water exchange function is associated with the freezing of water-saturated rocks and thawing of ice-saturated ones. The author gives individual consideration to the water exchange role of the active layer and the effect of the permafrost long-term dynamics on water exchange direction and scale. The water exchange function of the active layer appears due to the seasonal phase transitions of groundwater from a liquid to a solid state and back. Thus, the volume of water formed by the thawing of underground ice accumulated in the active layer in winter has been estimated about 4·1012 m3. In this regard, it is proposed to give cryohydrogenic part associated with the seasonal transitions of groundwater from the liquid to solid state and back in the active layer of the cryolithozone independent consideration within the hydrological (climatic) cycle of the natural water circulation. It is most certain that the permafrost water exchange function is more significant being associated with longterm permafrost development dynamics under the influence of periodic dramatic climate fluctuations. Thus, during the Holocene climatic optimum about 4.5·1015 m3 of underground ice was converted to the liquid phase. The intensity of water formed from the melting of this amount of ice inflowing its surface and underground reservoirs has been estimated about 820 km3 per year. This fact considered, the author proposes to consider the cryolithogenic part separately in the geological cycle of the natural water cycle.

scholarly journals Understanding solid-state processing of pharmaceutical cocrystals via milling: Role of tablet excipients

2021 ◽  
Vol 601 ◽  
pp. 120514 ◽  
Author(s):  
Rahamatullah Shaikh ◽  
Saeed Shirazian ◽  
Sarah Guerin ◽  
Eoin Sheehan ◽  
Damien Thompson ◽  
...  
Keyword(s):  
Solid State ◽  
Pharmaceutical Cocrystals ◽  
Tablet Excipients ◽  
State Processing

The Role of Protons and Formation Cu(NH3)2+ During Ammonia-Assisted Solid-State Ion Exchange of Copper(I) Oxide into Zeolites

2018 ◽  
Vol 62 (1-4) ◽  
pp. 100-107 ◽  
Author(s):  
Peter N. R. Vennestrøm ◽  
Lars F. Lundegaard ◽  
Christoffer Tyrsted ◽  
Dmitriy A. Bokarev ◽  
Alina I. Mytareva ◽  
...  
Keyword(s):  
Solid State ◽  
Ion Exchange

Role of solid-state structure in propene hydrogenation with nickel catalysts

1990 ◽  
Vol 86 (4) ◽  
pp. 739 ◽  
Author(s):  
Giovanni Carturan ◽  
Stefano Enzo ◽  
Renzo Ganzerla ◽  
Maurizio Lenarda ◽  
Roberto Zanoni
Keyword(s):  
Solid State ◽  
Nickel Catalysts ◽  
State Structure ◽  
Solid State Structure

scholarly journals Electrochemiluminescence Study of Europium (III) Complex with Coumarin3-Carboxylic Acid

2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
Stefan Lis ◽  
Krzysztof Staninski ◽  
Tomasz Grzyb
Keyword(s):  
Aqueous Solution ◽  
Spectral Analysis ◽  
Energy Transfer ◽  
Solid State ◽  
Carboxylic Acid ◽  
Elemental Analysis ◽  
Aluminium Electrode ◽  
The Eu

The europium (III) complex of coumarin-3-carboxylic acid (C3CA) has been prepared and characterized on the basis of elemental analysis, IR, and emission (photoluminescence and electrochemiluminescence) spectroscopy. The synthesised complex having a formula Eu was photophysically characterized in solution and in the solid state. Electrochemiluminescence, ECL, of the system containing the Eu(III)/C3CA complex was studied using an oxide-covered aluminium electrode. The goal of these studies was to show the possibility of the use of electrochemical excitation of the Eu(III) ion in aqueous solution for emission generation. The generated ECL emission was very weak, and therefore its measurements and spectral analysis were carried out with the use of cut-off filters method. The studies proved a predominate role of the ligand-to-metal energy transfer (LMET) in the generated ECL.

Pressure cycles and the water economy of insects

1988 ◽  
Vol 318 (1190) ◽  
pp. 377-407 ◽  
Keyword(s):  
Body Temperature ◽  
Water Exchange ◽  
Vapour Phase ◽  
The Body ◽  
Tracheal System ◽  
Water Economy ◽  
Insect Wings ◽  
Pressure Cycle ◽  
Respiratory Gases

Water exchange between insects and their environment via the vapour phase includes influx and efflux components. The pressure cycle theory postulates that insects (and some other arthropods) can regulate the relative rates of influx and efflux of water vapour by modulating hydrostatic pressures at a vapour-liquid interface by compressing or expanding a sealed, gas-filled cavity. Some such cavities, like the tracheal system, could be compressed by elevated pressure in all or part of the haemocoele. Others, perhaps including the muscular rectum of flea prepupae, could be compressed by intrinsic muscles. Maddrell Insect Physiol . 8, 199 (1971)) suggested a pressure cycle mechanism of this kind to account for rectal uptake of water vapour in Thermobia but did not find it compatible with quantitative information then available. Newer evidence conforms better with the proposed mechanism. Cyclical pressure changes are of widespread occurrence in insects and have sometimes been shown to depend on water status. Evidence is reviewed for the role of the tracheal system as an avenue for net exchange of water between the insect and its environment. Because water and respiratory gases share common pathways, most published findings fail to distinguish between the conventional view that the tracheal system has evolved as a site for distribution and exchange of respiratory gases and that any water exchange occurring in it is generally incidental and nonadaptive, and the theory proposed here. The pressure cycle theory offers a supplementary explanation not incompatible with evidence so far available. The relative importance of water economy and respiratory exchange in the functioning of compressible cavities such as the tracheal system remains to be explored. Some further implications of the pressure cycle theory are discussed. Consideration is given to the possible involvement of vapour-phase transport in the internal redistribution of water within the body. It is suggested that some insect wings may constitute internal vapour-liquid exchange sites, where water can move from the body fluids to the intratracheal gas. Ambient and body temperature must influence rates of vapour-liquid mass transfer. If elevated body temperature promotes evaporative discharge of the metabolic water burden that has been shown to accumulate during flight in some large insects, their minimum threshold thoracic temperature for sustained flight may relate to the maintenance of water balance. The role of water economy in the early evolution of insect wings is considered. Pressure cycles might help to maintain water balance in surface-breathing insects living in fresh and saline waters, but the turbulence of the surface of the open sea might prevent truly marine forms from using this mechanism.

Investigation of the role of anions in hydrotalcite for quasi-solid state dye-sensitized solar cells application

2013 ◽  
Vol 1 (13) ◽  
pp. 4345 ◽  
Author(s):  
Xiu Wang ◽  
Ran Deng ◽  
Sneha A. Kulkarni ◽  
Xiaoyan Wang ◽  
Stevin Snellius Pramana ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solid State ◽  
Dye Sensitized Solar Cells ◽  
Dye Sensitized ◽  
Sensitized Solar Cells

scholarly journals Suppressing Void Formation in All-Solid-State Batteries: The Role of Interfacial Adhesion on Alkali Metal Vacancy Transport

2021 ◽  
Author(s):  
Ieuan Seymour ◽  
Ainara Aguadero
Keyword(s):  
Solid State ◽  
Interfacial Adhesion ◽  
Void Formation ◽  
Rechargeable Batteries ◽  
Metal Anode ◽  
Solid State Batteries ◽  
Promising Solution ◽  
Metal Vacancy ◽  
All Solid State Batteries

All-solid-state batteries containing a solid electrolyte and a lithium (Li) or sodium (Na) metal anode are a promising solution to simultaneously increase the energy density and safety of rechargeable batteries....

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