411 research outputs found
Геофизические исследования скважин для выявления коллекторов и определения их фильтрационно-емкостных свойств на Вынгаяхинском газо-нефтяном месторождении (Тюменская область)
Объектом исследования является месторождение Вынгаяхинское. Цель работы – проектирование комплекса геофизических методов исследования скважин с целью изучения пластов- коллекторов Вынгаяхинского месторождения (ЯНАО). В процессе исследования проводились сбор и анализ геофизических материалов для обоснования оптимального комплекса. В результате исследования предложен комплекс ГИС для выявления и исследования нефтенасыщенных коллекторов. Область применения: предназначаемый комплекс ГИС может применяться на любых месторождениях нефти с терригенно-поровым типом коллекторов. Экономическая значимость работы определяется необходимостью исследований для подсчетов запасов.The object of this study is to deposit Vyngayakhinskoye. The purpose of the work - design of geophysical methods for wells to examine plastov- collectors Vyngayakhinskoye deposit (Yamalo-Nenets District). The study carried out collection and analysis of geophysical data to support the optimum combination. The study proposed a set of GIS for the detection and investigation of oil-saturated reservoir.
Scope: intended complex GIS can be used on any oil fields with terrigenous pore type reservoirs. The economic significance of the work is determined by the necessity of research for calculation of reserves
Сложность алгоритмов криптографической системы Эль–Гамаля и ихэффективность
Objective. - Electrical remodeling as well as atrial contractile dysfunction after the conversion of atrial fibrillation (AF) to sinus rhythm (SR) are mainly caused by a reduction of the inward L-type Ca2+ current (ICaL). We investigated whether the expression of L-type Ca2+-channel subunits was reduced in atrial myocardium of AF patients. Methods. - Right atrial appendages were obtained from patients undergoing coronary artery bypass graft surgery (CAD, n = 35) or mitral valve surgery (MVD, n = 37). Seventeen of the CAD patients and 18 of the MVD patients were in chronic (>3 months) AF, whereas the others were in SR. The protein expression of the L-type Ca2+-channel subunits {alpha}1C and {beta}2 was quantified by western blot analysis. Furthermore, we measured the density of dihydropyridine (DHP)-binding sites of the L-type Ca2+ channel using 3H-PN220-100 as radioligand. Results. - Surprisingly, the {alpha}1C and the {beta}2-subunit expression was not altered in atrial myocardium of AF patients. Also, the DHP-binding site density was unchanged. Conclusion. - The protein expression of the L-type Ca2+-channel subunits {alpha}1C or {beta}2 is not reduced in atrial myocardium of AF patients. Therefore, the reduced ICaL might be due to downregulation of other accessory subunits ({alpha}2{delta}), expression of aberrant subunits, changes in channel trafficking or alterations in channel function
Effective interactions between star polymers and colloidal particles
Using monomer-resolved Molecular Dynamics simulations and theoretical
arguments based on the radial dependence of the osmotic pressure in the
interior of a star, we systematically investigate the effective interactions
between hard, colloidal particles and star polymers in a good solvent. The
relevant parameters are the size ratio q between the stars and the colloids, as
well as the number of polymeric arms f (functionality) attached to the common
center of the star. By covering a wide range of q's ranging from zero (star
against a flat wall) up to about 0.75, we establish analytical forms for the
star-colloid interaction which are in excellent agreement with simulation
results. A modified expression for the star-star interaction for low
functionalities, f < 10 is also introduced.Comment: 37 pages, 14 figures, preprint-versio
Estimate of the Prevalence of Transmitted Drug Resistance (TDR) and Acquired Drug Resistance (ADR) in a HIV Resistance Study of the German ClinSurv-HIV Cohort
Estimate of the Prevalence of Transmitted Drug Resistance (TDR) and Acquired Drug Resistance (ADR) in a HIV Resistance Study of the German ClinSurv-HIV Cohort
Research of the Additional Losses Occurring in Optical Fiber at its Multiple Bends in the Range Waves 1310nm, 1550nm and 1625nm Long
Article is devoted to research of the additional losses occurring in the optical fiber at its multiple bends in the range waves of 1310 nanometers, 1550 nanometers and 1625 nanometers long. Article is directed on creation of the external factors methods which allow to estimate and eliminate negative influence. The automated way of calculation of losses at a bend is developed. Results of scientific researches are used by engineers of "Kazaktelekom" AS for practical definition of losses service conditions. For modeling the Wolfram|Alpha environment - the knowledge base and a set of computing algorithms was chosen. The greatest losses are noted on wavelength 1310nm and 1625nm. All dependences are nonlinear. Losses with each following excess are multiplicative
Soft Interaction Between Dissolved Dendrimers: Theory and Experiment
Using small-angle neutron scattering and liquid integral equation theory, we
relate the structure factor of flexible dendrimers of 4th generation to their
average shape. The shape is measured as a radial density profile of monomers
belonging to a single dendrimer. From that, we derive an effective interaction
of Gaussian form between pairs of dendrimers and compute the structure factor
using the hypernetted chain approximation. Excellent agreement with the
corresponding experimental results is obtained, without the use of adjustable
parameters. The present analysis thus strongly supports the previous finding
that flexible dendrimers of low generation present fluctuating structures akin
to star polymers.Comment: 20 pages, 4 figures, submitted to Macromolecules on July 24, 200
Polydisperse star polymer solutions
We analyze the effect of polydispersity in the arm number on the effective
interactions, structural correlations and the phase behavior of star polymers
in a good solvent. The effective interaction potential between two star
polymers with different arm numbers is derived using scaling theory. The
resulting expression is tested against monomer-resolved molecular dynamics
simulations. We find that the theoretical pair potential is in agreement with
the simulation data in a much wider polydispersity range than other proposed
potentials. We then use this pair potential as an input in a many-body theory
to investigate polydispersity effects on the structural correlations and the
phase diagram of dense star polymer solutions. In particular we find that a
polydispersity of 10%, which is typical in experimental samples, does not
significantly alter previous findings for the phase diagram of monodisperse
solutions.Comment: 14 pages, 7 figure
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