200 research outputs found

    A powerful computational crystallography method to study ice polymorphism

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    Classical Molecular Dynamics (MD) simulations are employed as a tool to investigate structural properties of ice crystals under several temperature and pressure conditions. All ice crystal phases are analyzed by means of a computational protocol based on a clustering approach following standard MD simulations. The MD simulations are performed by using a recently published classical interaction potential for oxygen and hydrogen in bulk water, derived from neutron scattering data, able to successfully describe complex phenomena such as proton hopping and bond formation/breaking. The present study demonstrates the ability of the interaction potential model to well describe most ice structures found in the phase diagram of water and to estimate the relative stability of sixteen known phases through a cluster analysis of simulated powder diagrams of polymorphs obtained from MD simulations. The proposed computational protocol is suited for automated crystal structure identification.Comment: RevTex 4.1, 7 figures - to be published in the Journal of Chemical Physic

    Cultural and national features of the language representation of the concept “money” in the Russian and French advertisement print texts

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    The article is devoted to the problem of cultural and national features of the language representation of the concept “money" in the Russian and French languages. The paper deals with the comparative analysis of advertisement print texts containing the various lexical units of the concept “money". The representation of the given concept confirms considerable differences of peripheral layers caused by a national and cultural, social and economic backgroundyesBelgorod State Universit

    Influence of platelets rich plasma (PRP) on the regeneration of skin conditions allergic dermatitis

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    Introduction: Modern approach to the problem of skin diseases characterized by the influence on the regeneration of tissues at the cellular level, leading to restoration of structure and function of the body as a whole. Aim: to examine the effects of PRP on regenerative properties of skin conditions allergic dermatitis. Materials and methods: Experiments were performed on female mice ICR, aged 3-4 months. PRP received by treating peripheral blood Machinery Smart Prep (Harvester Corp.). Animals were divided into two groups. The first group in plot area for 10 days rubbed potassium dichromate, then locally, intradermal injected into the alfected area PRP dose of 0.1 ml twice at intervals of 7 days. The second group of animals rubbed dichromate of potassium, during the same periodand then watched the self-healing skin. Animal deduced from the experiment on the 17th, 31st and 45th day. Conducted pathologic study involved skin using different methods of coloring material. Results: Macroscopically, visible damages to skin were not observed at the animals of the first group. The skin was covered with hair. In the morphological study of the skin revealed the preservation of its layer structure, satisfactory vascularization of the zone lesions, expressed basal layer, the structure of hair is not changed. Macroscopically, the skin of the animals from the second group was thin, with varying degrees of proliferation of connective tissue. Microscopically we detected acanthosis, small spongiosis, without bubbles, leukocyte infiltration of various degrees of severity, extension of epidermal outgrowths, areas of parakeratosis and phenomenon of acantholysis. Blood vessels had a small caliber. Conclusions: PRP promotes high quality and rapid reparative regeneration of skin, which helps preserve the morphological properties of tissue. The positive effect correction caused by several factors (cytokines and other biologically active substances), which enhance chemotaxis and proliferation of cellular elements in the lesion focus, and participate in the processes of adaptation

    Improving the efficiency of using resource base of liquid hydrocarbons in Jurassic deposits of Western Siberia

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    Under conditions of the same type of oil deposits with hard-to-recover reserves in Jurassic terrigenous reservoirs of the West Siberian oil and gas province, a study was made about the influence of the geological structure features of objects and water flooding technologies on the response degree of production wells to water injection. Response degree of the wells was determined by analyzing the time series of production rates and injection volumes of injection wells with the calculation of inter-correlation function (ICF) values. It was believed that with ICF values in a given injection period of more than 0.5, production well responds to the injection. Factors that have a prevailing effect on water flooding success have been identified. Among them: effective oil-saturated thickness of the formation in production wells; relative amplitude of the self polarization of the formation in both production and injection wells; grittiness coefficient of the formation in injection wells; monthly volume of water injection and distance between wells. Methodological approach is proposed based on the application of the proposed empirical parameter of water flooding success, which involves the use of indirect data in conditions of limited information about the processes occurring in the formation at justification and selection of production wells for transferring them to injection during focal flooding; drilling of additional production and injection wells – compaction of the well grid; shutdown of injection and production wells; use of a transit wells stock; use of cyclic, non-stationary flooding in order to change the direction of filtration flows; determining the design of dual-purpose L-shaped wells (determining length of the horizontal part); limitation of flow rate in highly flooded wells with a high degree of interaction; determination of decompression zones (without injection of indicators), stagnant zones for drilling sidetracks, improving the location of production and injection wells, transferring wells from other horizons; choosing the purpose of the wells during implementation of the selective water flooding system in order to increase the efficiency of using the resource base of liquid hydrocarbons

    SIGMA and XTE observations of the soft X-ray transient XTEJ1755-324

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    We present observations of the X-ray transient XTEJ1755-324 performed during summer 1997 with the XTE satellite and with the SIGMA hard X-ray telescope onboard the GRANAT observatory. The source was first detected in soft X-rays with XTE on July 25 1997 with a rather soft X-ray spectrum and its outburst was monitored in soft X-rays up to November 1997. On September 16 it was first detected in hard X-rays by the French soft gamma ray telescope SIGMA during a Galactic Center observation. The flux was stronger on September 16 and 17 reaching a level of about 110 mCrab in the 40-80 keV energy band. On the same days the photon index of the spectrum was determined to be alpha =-2.3 +/- 0.9 (1 sigma error) while the 40-150 keV luminosity was about 8 x 10^{36} erg/s for a distance of 8.5 kpc. SIGMA and XTE results on this source indicate that this source had an ultrasoft-like state during its main outburst and a harder secondary outburst in September. These characteristics make the source similar to X-Nova Muscae 1991, a well known black hole candidate.Comment: 19 pages LaTeX, 6 Postscript figures included, Accepted by Astrophysical Journa

    Совершенствование механизмов субсидирования региональных перевозок в России

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    The article describes the results of research and verification of amounts of required budgetary funds for regional transportation subsidization in Russia.Излагаются результаты исследования и обоснования размеров необходимых бюджетных средств для субсидирования региональных авиаперевозок в России

    The improvement of management of housing and communal services

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    В статье рассмотрено функционирование современной системы муниципального управления жилищно-коммунальным хозяйством в России.The article describes the functioning of a modern system of municipal management of housing and communal services in Russia

    Вплив легувальної добавки на теплофізичні та реологічні властивості полімерної композиції, що не містить галогенів, для ізоляції та оболонок кабелів

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    Introduction. The demand for halogen-free fire-resistant compositions for the manufacture of fire-retardant wires and cables is constantly growing. Problem. Therefore, the creation and further processing of these materials is an urgent problem. Goal. The aim of the article is to study the effect of the doping additive on the thermophysical and rheological properties of halogen-free compositions for power cables with voltage 1 kV with the determination of both the temperatures of phase and structural transformations of polymer compositions. Methodology. Experiments investigating the phase transformations were carried out with the help device of thermogravimetric analysis and differential scanning calorimetry TGA/DSC 1/1100 SF of METTLER TOLEDO company. Rheological studies of polymeric materials were conducted by using the method of capillary viscosimetry in the device IIRT–AM. Results. The influence of the doping additive on the formation of the supramolecular structure of the filled polymer compositions for cable products was determined, that resulted in the temperature increase of the decomposition beginning by 11 °С and the end of decomposition by 7 °С. Originality. The effect of a doping additive on reducing the effective melt viscosity of a polymer composition from 6·104 to 1·104 Pa·s with increasing shear rate has been shown for the first time. The shear rate of the polymer composition containing the doping additive increases from 0.5 to 20 s–1 with increasing shear stress. Practical value. The research results provide an opportunity to reasonably approach the development of effective technological processes for the manufacture of the insulation and sheaths of power cables from halogen-free polymer compositions.Попит на вогнестійкі композиції, що не містять галогенів, для виготовлення пожежобезпечних проводів та кабелів безперервно зростає. Тому розробка цих матеріалів є актуальною проблемою. Метою статті є дослідження впливу легувальної добавки на теплофізичні та реологічні властивості композицій. Теплофізичні властивості визначено з використанням приладу TGA/DSC 1/1100 SF компанії METTLER TOLEDO. Реологічні дослідження полімерних матеріалів проведено методом капілярної віскозиметрії на приладі ИИРТ-АМ. Визначено вплив легувальної добавки на формування надмолекулярної структури наповнених полімерних композицій. Встановлено зниження ефективної в’язкості розплаву полімерної композиції в 6 разів зі зростанням швидкості зсуву в 40 разів при зміненні температури від 150 до 190 °С. Швидкість зсуву полімерної композиції з легувальною добавкою зростає в 40 разів з підвищенням напруження зсуву в 9 разів. Результати досліджень дають можливість обґрунтовано підходити до розроблення ефективних технологічних процесів виготовлення ізоляції та оболонок силових кабелів
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