132 research outputs found

    Analysis of the Efficiency PETSc and PETIGA Libraries in Solving the Problem of Crystal Growth

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    We present an analysis of high performance computational method for solving the problem of crystal grows. The method uses PETSc and PETIGA C-language based libraries and supports parallel computing. The evolution of calculation process was studied in series of special computations are obtained on innovative mobile cluster platform, which provides exclusive system tuning abilities. The results of research confirm the high efficiency of the proposed algorithm on multi-core computer systems and allow us to recommend the use of PETSc and PETIGA for solving high order differential equations

    Comparative analysis of oxidative metabolism indicators at acute alcohol and acute surrogate alcohol intoxication

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    High level of population alcoholization is the cause of many cases of acute alcohol and alcoholic surrogate intoxication. The number of alcohol intoxication cases in Kazakhstan in 2014 amounted to 13891 (80.3 per 100 000 people), the number of fatal intoxication cases amounted to 882 (5.1 per 100 000 people). The problem of alcoholization in Russia remains urgent as well: according to the statistics of 2014,152 551 cases of acute intoxication of chemical etiology were registered, 33.9 % of cases occurred due to alcohol intoxication. Alcoholic beverages in the course of their biotransformation to acetic acid can form oxygen free radicals in particular superoxide anion as a byproduct of acetic aldehyde oxidation reaction. Studies on oxidative metabolism of ethanol intoxication are currently being conducted. At the same time, the state of oxidative metabolism during alcoholic surrogate intoxication was not practically investigated. Evaluation of oxidative metabolism depending on the severity of alcohol or its surrogate intoxication is of special interest. The aim was to compare oxidative metabolism indicators among patients with acute alcohol and alcoholic surrogate intoxication of different severity. The object of the study was blood of 62 people with diagnosed moderate or severe degrees of acute alcohol and alcoholic surrogate intoxication. Indicators of oxidative metabolism in erythrocytes and blood plasma were estimated. Significant differences were found in product concentration of protein oxidation containing bityrosine crosslinks in blood plasma under increase of alcohol intoxication degree

    The effectiveness of parallelizing an algorithm of the PFC equation solution using PetIGA library

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    The paper presents an algorithm for solving the equation of Phase Field Crystal (PFC) in a hyperbolic statement that allows to describe the phase transitions of metastable or unstable state at the nuclear density scale, described by a differential equation of the sixth order with respect to the space variable and the second order with respect to the time variable. The algorithm is based on the method of isogeometric analysis (IGA) and is implemented by PetIGA library. The resulting code allows parallel computations, which significantly speeds up the process of solving a problem. The effectiveness of used instruments during the calculations on high-performance computing clusters is evaluated. An analysis of the effectiveness of the current algorithm is carried out for heterogeneous computer systems

    Landscape science: a Russian geographical tradition

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    The Russian geographical tradition of landscape science (landshaftovedenie) is analyzed with particular reference to its initiator, Lev Semenovich Berg (1876-1950). The differences between prevailing Russian and Western concepts of landscape in geography are discussed, and their common origins in German geographical thought in the late nineteenth and early twentieth centuries are delineated. It is argued that the principal differences are accounted for by a number of factors, of which Russia's own distinctive tradition in environmental science deriving from the work of V. V. Dokuchaev (1846-1903), the activities of certain key individuals (such as Berg and C. O. Sauer), and the very different social and political circumstances in different parts of the world appear to be the most significant. At the same time it is noted that neither in Russia nor in the West have geographers succeeded in specifying an agreed and unproblematic understanding of landscape, or more broadly in promoting a common geographical conception of human-environment relationships. In light of such uncertainties, the latter part of the article argues for closer international links between the variant landscape traditions in geography as an important contribution to the quest for sustainability

    Prospects in Analytical Atomic Spectrometry

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    Tendencies in five main branches of atomic spectrometry (absorption, emission, mass, fluorescence and ionization spectrometry) are considered. The first three techniques are the most widespread and universal, with the best sensitivity attributed to atomic mass spectrometry. In the direct elemental analysis of solid samples, the leading roles are now conquered by laser-induced breakdown and laser ablation mass spectrometry, and the related techniques with transfer of the laser ablation products into inductively-coupled plasma. Advances in design of diode lasers and optical parametric oscillators promote developments in fluorescence and ionization spectrometry and also in absorption techniques where uses of optical cavities for increased effective absorption pathlength are expected to expand. Prospects for analytical instrumentation are seen in higher productivity, portability, miniaturization, incorporation of advanced software, automated sample preparation and transition to the multifunctional modular architecture. Steady progress and growth in applications of plasma- and laser-based methods are observed. An interest towards the absolute (standardless) analysis has revived, particularly in the emission spectrometry.Comment: Proofread copy with an added full reference list of 279 citations. A pdf version of the final published review may be requested from Alexander Bol'shakov <[email protected]
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