200 research outputs found
A powerful computational crystallography method to study ice polymorphism
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
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
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
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
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
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
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
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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