THE COMPUTER SIMULATION OF THE MOLECULAR STRUCTURE OF SELENIUM ELECTROPHOTOGRAPHIC LAYER

The modern selenium electrophotographic photosensor is a multilayer system in which different properties of various layers are attained by changes in the material molecular structure without any changes in its chemical composition. The models of the selenium molecular structure at different distances from the surface of the electrophotographic layer are considered. The changes of the bond length, the bond angle and the dihedral angle distributions are analysed for various parts of the layer. The correlation between the form of the third peak of RDF and the short range order parameters of selenium is defined

Prediction of sanding in subsurface hydrocarbon reservoirs.

Sand production in oil and gas wells can occur if the fluid velocity exceeds a certain value. Due to drilling operations, the mechanical stresses can exceed the load bearing capacity of the rock. As the local stresses exceed certain level, a certain amount of rock is fractured into sand. Then, the sand is carried by the fluid through the wellbore depending on the flow rate. The amount of the solids can be less than a few grams per cubic meter of reservoir fluid or an essential amount. In the later case erosion of the rock and removing sufficient quantities of rock can occur. This can produce subsurface cavities which collapse and destroy the well. When sanding is unavoidable it is necessary to estimate the characteristics of the process. Our aim was to generate a simple one-dimensional local model, which predicts the volume of sanding, the radius and the porosity of the yielded zone. Such model will help the company in the development of complex 3D models

Development of the energy efficient residential low-rise house concept for the Ural region

In the article the problem of energy-efficient construction in Russia is considered. The energy-saving technologies and renewable energy sources acceptable in construction in the Ural region analysis is carried out. Main reasons of the irrational consumption of thermal energy are highlighted and the strategy of the energy-efficient construction development in the Urals is described. As a result of the research, a conceptual project of an individual residential house was developed. © Published under licence by IOP Publishing Ltd

“Green” Synthesis of Sucrose Octaacetate and Characterization of Its Physicochemical Properties and Antimicrobial Activity

Sucrose octaacetate (octa-O-acetylsucrose) has been synthesized by esterification of sucrose with acetic anhydride using ultrasound-assisted irradiation. This sucrose ester is a white, water-insoluble substance with a bitter taste. The FT-IR and NMR spectra confirmed acetylation and revealed the hydrophobic incorporation in sucrose molecule. Furthermore, the foamability, foam stability, emulsification and antimicrobial properties of octa-O-acetylsucrose were evaluated. Foams and 50 % (oil/water) model emulsions were prepared with 2 % (w/w) octa-O-acetylsucrose. The obtained results demonstrate the formation of emulsions and foams with high stability (50–70 %). The antimicrobial activity of octa-O-acetylsucrose was evaluated against seventeen microorganisms (Gram-positive and Gram-negative bacteria, yeasts, and fungi). Octa-O-acetylsucrose inhibited the growth of fungi Penicillium sp., Rhizopus sp. and Fusarium moniliforme at 5 mg cm–3, and yeasts Candida albicans at 1 mg cm–3. Inhibition against Gram-positive and Gram-negative bacteria was not observed. The obtained results demonstrate the potential applications of octa-O-acetylsucrose as a foaming agent, oil-in-water emulsion stabilizer, and antifungal substance in pharmaceutical and cosmetic preparations. This work is licensed under a Creative Commons Attribution 4.0 International License

Linear magnetoresistance in compensated graphene bilayer

We report a nonsaturating linear magnetoresistance in charge-compensated bilayer graphene in a temperature range from 1.5 to 150 K. The observed linear magnetoresistance disappears away from charge neutrality ruling out the traditional explanation of the effect in terms of the classical random resistor network model. We show that experimental results qualitatively agree with a phenomenological two-fluid model taking into account electron-hole recombination and finite-size sample geometry

Structural, transport and microwave properties of 123/sapphire films: Thickness effect

The effect of thickness and growth conditions on the structure and microwave properties has been investigated for the 123/sapphire films. It has been shown that in the conditions of epitaxial growth the Al atoms do not diffuse from substrate into the film and the films with thickness up to 100 nm exhibit the excellent direct current (DC) properties. The increase of thickness of GdBaCuO films causes the formation of extended line-mesh defects and the increase of the surface resistance (R(sub S)). The low value of surface resistance R(sub S)(75 GHz, 77K) = 20 mOhm has been obtained for the two layer YBaCuO/CdBaCuO/sapphire films

Strategies for energy saving in the sphere of construction and operation of buildings and structures

The operational energy consumption of existing residential and public buildings in Russia is about 3 times higher than in industrialized countries with similar climatic characteristics. Active controversy, energy-saving programs, theoretical developments, experimental facilities implemented in the last 10–15 years, have not yet had a practical effect on the energy intensity of cities and settlements, but have created realistic prerequisites for reducing the energy consumption of buildings and structures.Эксплуатационное энергопотребление существующих жилых и общественных зданий в России примерно в 3 раза превышает аналогичные показатели в технически развитых странах со сходными природно-климатическими характеристиками. Активная полемика, энергосберегающие программы, теоретические разработки, экспериментальные объекты, осуществляемые в последние 10–15 лет, пока не оказали практического влияния на энергоемкость городов и поселений, но создали реалистичные предпосылки для снижения энергопотребления зданий и сооружений

COMPARATIVE ANALYSIS OF THE USING THE HOT WATER SUPPLY AND HEATING SYSTEMS ENERGY EFFICIENT SOLUTIONS IN THE URAL CONDITIONS

Renewable and inexhaustible sources attract more and more attention every year. We analyzed two solutions for hot water supply and heating based on inexhaustible energy sources. An analysis of the use of solar collectors and heat pumps in the Urals has been made; a comparison of the payback periods has been presented.С каждым годом возобновляемые и неисчерпаемые источники энергии привлекают к себе все больше внимания. В данной работе проанализированы два решения систем горячего водоснабжения и отопления зданий на основе неисчерпаемых источников энергии. Произведен анализ их применения на территории Урала, представлено сравнение сроков их окупаемости