crystalline water
Recently Published Documents


TOTAL DOCUMENTS

94
(FIVE YEARS 21)

H-INDEX

18
(FIVE YEARS 1)

2021 ◽  
Vol 43 (5) ◽  
pp. 19-34
Author(s):  
V. M. Shestopalov ◽  
L. I. Petrenko ◽  
I. M. Romanyuk

Global warming, which has been observed in the world and Ukraine in particular in recent decades, may lead to a decrease in surface and groundwater. In addition, the high level of groundwater pollution and the policy of water purification is a matter of concern. Thus, the question of finding additional and alternative sources of drinking water today is highly urgent. A significant percentage of prospecting works of the last century was devoted to discovering the groundwater fields in fractured crystalline rocks of the Ukrainian Shield. As a rule, the productivity of wells of these formations did not have high flow rates, so even now, mostly the aquifers in sedimentary deposits have been exploited. The low productivity of most wells in water-bearing fractured rocks is associated with the unknown degree of fracturing of the crystalline massif: it is difficult to determine the pathways of groundwater inflow into the fracture system and, accordingly, it is not easy to justify the exploitable groundwater reserves. In this paper, using the groundwater flow model of the Zhashkiv groundwater deposit, it is considered an increase of the productivity of water intake wells in the water-bearing crystalline rocks due to the increasing degree of their fracturing by an explosion. Thus, in hydrogeology, this technique is known when trying to increase the permeability in the near-borehole space, but as a method of artificial recharge of aquiferous crystalline rocks is used very rarely. The paper also examines typical water intakes conditions in fractured crystalline water-bearing rocks, which can be recommended for increasing their productivity by the blasting method. The results indicate that an artificial increase in fracturing degree can have a significant effect on increasing the productivity of water intakes. The basic methods of using explosives, as an example of an artificial increase in fracturing degree, in solving hydrogeological problems and the mechanisms of fractures’ formation during the action of blasting are considered.


2021 ◽  
pp. 27-29
Author(s):  
Takashiro Akitsu ◽  
Shintaro Suda ◽  
Natsuki Katsuumi

We faced an example of re-reporting of the crystal structure, which was studied from another perspective. With the development of data-driven science, the efficiency of all researchers may be improved if the rules of data "reuse", which are different from "novelty", are established. In this context, the crystal structure of a copper(II) complex with 2,6-pyridine dicarboxylic acid, C14H8O8CuN2.H2O (monohydrate), was re-determined by us again. It has a different number of crystalline water molecules in a crystal of the same copper(II) complex previously reported (trihydrate). Interestingly, both crystal structures have been reported again and again by many researchers for a long time. What’s novelty for each report?


Author(s):  
yu chen ◽  
yuan yan ◽  
gang sun ◽  
wei liu ◽  
ming ma ◽  
...  

Abstract The major obstacle prohibiting the practical application of Sn-based anodes is drastic volume variation during cycling processes. Here, polyacrylonitrile (PAN) was acted as carbon source, stannic chloride pentahydrate (SnCl4.5H2O) and antimony chloride (SbCl3) were used as SnSb precursors. SnSb/C nanofibers were prepared via simple electrospinning, deep cryogenic treatment, and carbonization, its applied in anode materials for Lithium ion Batteries (LIBs) to achieve excellent cycle performance(115.5% capacity retention for 100 cycles). The improvement of electrochemical performance is mainly attributed to the synergistic effect of deep cryogenic treated special SnSb/C nanofibers precursor. In the deep cryogenic treatment process, the crystalline water in the precursor has a pore forming effect, the porous nanofiber structure leads to the phenomenon of capacity increase. The above results indicate that comprehensive consideration of deep cryogenic treatment and nanofiber precursors is a new idea to enhance the electrochemical performance of LIBs anode materials.


2021 ◽  
Vol 887 ◽  
pp. 446-452
Author(s):  
Igor V. Bessonov ◽  
L.K. Bogomolova ◽  
Alexey D. Zhukov ◽  
E.A. Zinoveva

Systems of floor insulation on the ground, isolation of roads and shallow foundations suggest the use of heat-insulating products resistant to moisture, the minerals contained in it, having low heat conductivity and water absorption and relatively high strength for compressive loads.The aim of the research was to study the possibility of using mineral substances containing crystalline water as a dispersed component. Firstly, such compounds as a reinforcing component increase the strength characteristics of products. Secondly, being flame retardants, they contribute to increasing the fire safety of materials and building systems in which these materials are used. To achieve this goal, two particular tasks were set: determination of the optimal consumption of mineral modifying additives; assessment of exploitative stability of the received products. It was found that the introduction of a mineral modifying additive can significantly increase the compressive strength by 10% deformation of samples from extruded polystyrene foam. The exploitative stability of products with a mineral additive varies slightly and depends on its consumption and uniform distribution in the product matrix. The effect of additive consumption on the change in the thermal conductivity of products has not been established. A nomogram has been built which allows one to evaluate the properties of products and determine the optimal consumption of a modifying additive.Systems of using products from modified extruded polystyrene foam in monolithic foundations with insulation for buildings erected on problem soils are considered.


2021 ◽  
pp. 632-645
Author(s):  
Aurèle Germain ◽  
Marta Corno ◽  
Piero Ugliengo

AbstractInterstellar Grains (IGs) spread in the Interstellar Medium (ISM) host a multitude of chemical reactions that could lead to the production of interstellar Complex Organic Molecules (iCOMs), relevant in the context of prebiotic chemistry. These IGs are composed of a silicate-based core covered by several layers of amorphous water ice, known as a grain mantle. Molecules from the ISM gas-phase can be adsorbed at the grain surfaces, diffuse and react to give iCOMs and ultimately desorbed back to the gas phase. Thus, the study of the Binding Energy (BE) of these molecules at the water ice grain surface is important to understand the molecular composition of the ISM and its evolution in time. In this paper, we propose to use a recently developed semiempirical quantum approach, named GFN-xTB, and more precisely the GFN2 method, to compute the BE of several molecular species at the crystalline water ice slab model. This method is very cheap in term of computing power and time and was already showed in a previous work to be very accurate with small water clusters. To support our proposition, we decided to use, as a benchmark, the recent work published by some of us in which a crystalline model of proton-ordered water ice (P-ice) was adopted to predict the BEs of 21 molecules relevant in the ISM. The relatively good results obtained confirm GFN2 as the method of choice to model adsorption processes occurring at the icy grains in the ISM. The only notable exception was for the CO molecule, in which both structure and BE are badly predicted by GFN2, a real pity due to the relevance of CO in astrochemistry.


CrystEngComm ◽  
2021 ◽  
Author(s):  
Ryuhei Okura ◽  
Hiromasa Uchiyama ◽  
Kazunori Kadota ◽  
Yuichi Tozuka

The structural transition behaviors of the hydration and dehydration of mequitazine glycolate (MQZ-GLC) after exposure to heat and relative humidity have yet not been clarified, although our previous study demonstrated...


2020 ◽  
Vol 117 (45) ◽  
pp. 27786-27787
Author(s):  
Jacek Wierzchos ◽  
Octavio Artieda ◽  
Carmen Ascaso ◽  
Fernando Nieto García ◽  
Petr Vítek ◽  
...  

2020 ◽  
Vol 59 (52) ◽  
pp. 23461-23465 ◽  
Author(s):  
Ryusuke Watanabe ◽  
Takeshi Sakamoto ◽  
Kosuke Yamazoe ◽  
Jun Miyawaki ◽  
Takashi Kato ◽  
...  

2020 ◽  
Vol 132 (52) ◽  
pp. 23667-23671
Author(s):  
Ryusuke Watanabe ◽  
Takeshi Sakamoto ◽  
Kosuke Yamazoe ◽  
Jun Miyawaki ◽  
Takashi Kato ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document