125 research outputs found

    Mann-whitney criterion

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    In the work, a practical problem is solved by Mann-Whitney test. Mann-Whitney test is a statistical criterion used to evaluate differences between two independent samples in terms of any sign of measured quantitatively; it allows to detect differences in the value of the parameter between small samples. This criterion is widely used in psychology for data analysis

    Loffe-Regel' crossover and boson peaks in disordered solid solutions and similar anomalies in heterogeneous crystalline structures

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    Low-frequency features of the phonon spectra of disordered solid solutions and heterogeneous crystalline structures are analyzed at the microscopic level. It is shown that boson-peak type excitations can arise in disordered solid solutions whose sites have only translational degrees of freedom. Thus it is established that such excitations appear mainly because of the additional positional dispersion of sound waves which is due to the disordering. The influence of boson-peak excitations on the low-temperature specific heat is investigated. It is found that in a number of cases the specific heat is more sensitive to excitations of this kind than the low-frequency density of states is. It is shown that anomalies similar to Ioffe-Regel' crossover and boson peaks can also arise in disordered heterogeneous crystalline structures with a complicated lattice

    Synthesis-Analysis of the Use of Cavitation Technologies

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    Анализ литературных источников в области использования кавитационных технологий показал, что эффекты кавитации используются в широком спектре промышленных технологий. В данной работе приведены основные результаты работ по кавитационной обработке различных жидких композиций, многокомпонентных сред в последние десятилетия. Представленный обзор позволяет сделать вывод об актуальности использования кавитационных технологий в различных областях техники и технологии для решения важных практических задач и, как следствие, необходимости их всестороннего изученияAn analysis of literature sources in the field of the use of cavitation technologies has shown that the effects of cavitation are used in a wide range of industrial technologies. This paper presents the main results of work on the cavitation treatment of various liquid compositions, multicomponent media in recent decades. The presented review allows us to conclude that the use of cavitation technologies in various fields of engineering and technology is relevant for solving important practical problems and, as a result, the need for their comprehensive stud
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