Study of the Stressed State Near the Crack That Initiates at the Inclusion Under Longitudinal Shift Wave Influence

The purpose of this paper is to study the stress state near the crack that initiates at the inclusion when subjected to a longitudinal shear wave. The formulated problem is reduced to a system of singular integro-differential equations with fixed singularities with respect to the unknown voltage surges and displacements on the surface of a defect. To solve this system, a similar collocation method is used. There have been shown dependences of the change in the dimensionless values of the stress intensity factors (SIF) on the dimensionless value of the wave number in the case of wave propagation at different angles.Метою цієї роботи є дослідження напруженого стану біля тріщини, що відходить від включення під впливом хвилі поздовжнього зсуву. Сформульована задача приведена до системи сингулярних інтегро-диференціальних рівнянь з нерухомими особливостями відносно невідомих стрибків напружень і переміщень на поверхні дефекту. Для розв’язання цієї системи використовується аналогічний колокаційний метод. Показано залежності зміни безрозмірних значень коефіцієнтів інтенсивності напружень (КІН) від безрозмірного значення хвильового числа у випадку поширення хвилі під різними кутами.Целью данной работы является исследование напряженного состояния возле трещины, которая отходит от включения при воздействии волной продольного сдвига. Сформулированная задача приведена к системе сингулярных интегро-дифференциальных уравнений с неподвижными особенностями относительно неизвестных скачков напряжений и перемещений на поверхности дефекта. Для решения этой системы используется аналогичный коллокационный метод. Показаны зависимости изменения безразмерных значений коэффициентов интенсивности напряжений (КИН) от безразмерного значения волнового числа в случае распространения волны под разными углами

Verification of Two-Parametric Fitting Method for Determination of Electron Beam Characteristics

Computer simulation of radiation processing allows correctly to schedule and control the performance of work on radiation processing installations. In particular, for radiation technology using electron beams (EBs) in the calculations it is required the values of energy characteristics of the electron irradiation. The paper [1] describes a method for the twoparametric fitting of semi-empirical model (PFSEM method) to the results of measuring the depth dependence of the absorbed dose for electron radiation performed by dosimetric wedge

Assessment of the strength reliability of high-temperature heat exchangers with long service life at the design stage

The article describes a method for assessing the strength reliability of high-temperature heat exchangers with service life of several tens of thousands of hours at the design stage, when there is not enough statistical data on the operating time of elements and material properties. The method shows, how to determine the missing coefficients of variation for calculating reliability and build the function of the probability of failure-free operation, considering the change of the properties of the structural material over time. The method of visualizing the distribution of zones, both satisfying and not satisfying reliability criteria at the nodes of any finite element model, is also described

Verification of Two-Parametric Fitting Method for Determination of Electron Beam Characteristics

Computer simulation of radiation processing allows correctly to schedule and control the performance of work on radiation processing installations. In particular, for radiation technology using electron beams (EBs) in the calculations it is required the values of energy characteristics of the electron irradiation. The paper [1] describes a method for the twoparametric fitting of semi-empirical model (PFSEM method) to the results of measuring the depth dependence of the absorbed dose for electron radiation performed by dosimetric wedge

Computer Simulations of the Band Structure and Density of States of the Linear Chains of NaCl Ions

The authors thank Eugene Kotomin and V. Kuzovkov for fruitful discussions and valuable suggestions. A.I.P thanks A.Moskina for the technical assistance in preparation of the manuscript. A.I.P also gratefully acknowledges a project LZP-2018/1-0214 from the Latvian Council of Science for partial support.The paper presents the results of first-principles computer simulations of the band structure, the density of states, and the total energy of NaCl (NaCl, Na2Cl2, Na3Cl3, Na4Cl4, Na6Cl6) linear chains of atoms. Modelling of the specified characteristics is realised in the computer code Atomistix ToolKit combined with Virtual NanoLab. The total energy depends on the number of ions in the nanoobject under study, but practically does not depend on the geometric arrangement of ions.Latvian Council of Science LZP-2018/1-0214; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART

Measurement of xF3xF_3 and F2F_2 Structure Functions in Low Q2Q^2 Region with the IHEP-JINR Neutrino Detector

The isoscalar structure functions $xF_3$ and $F_2$ are measured as functions of $x$ averaged over all $Q^2$ permissible for the range of 6 to 28 GeV of incident neutrino (anti-neutrino) energy at the IHEP-JINR Neutrino Detector. The QCD analysis of $xF_3$ structure function provides $\Lambda_{\bar{MS}}^{(4)} = (411 \pm 200)$ MeV under the assumption of QCD validity in the region of low $Q^2$. The corresponding value of the strong interaction constant $\alpha_S (M_Z) = 0.123^{+0.010}_{-0.013}$ agrees with the recent result of the CCFR collaboration and with the combined LEP/SLC result.Comment: 11 pages, 1 Postscript figure, LaTeX. Talk given at the 7th International Workshop on Deep Inelastic Scattering and QCD (DIS 99), Zeuthen, Germany, 19-23 Apr 199

Quasicondensate and superfluid fraction in the 2D charged-boson gas at finite temperature

The Bogoliubov - de Gennes equations are solved for the Coulomb Bose gas describing a fluid of charged bosons at finite temperature. The approach is applicable in the weak coupling regime and the extent of its quantitative usefulness is tested in the three-dimensional fluid, for which diffusion Monte Carlo data are available on the condensate fraction at zero temperature. The one-body density matrix is then evaluated by the same approach for the two-dimensional fluid with e^2/r interactions, to demonstrate the presence of a quasi-condensate from its power-law decay with increasing distance and to evaluate the superfluid fraction as a function of temperature at weak coupling.Comment: 9 pages, 2 figure

Measurement of ϕ\phi(1020) meson leptonic width with CMD-2 detector at VEPP-2M Collider

The $\phi$(1020) meson leptonic width has been determined from the combined analysis of 4 major decay modes of the resonance ($\phi\to K^+ K^-,K^0_LK^0_S,\pi^+\pi^-\pi^0,\eta\gamma$) studied with the CMD-2 detector at the VEPP-2M $e^+e^-$ collider. The following value has been obtained: $\Gamma(\phi\to e^+e^-) = 1.235\pm 0.006\pm 0.022$ keV. The $\phi(1020)$ meson parameters in four main decay channels have been also recalculated: $B(\phi\to K^+K^-) = 0.493\pm 0.003\pm 0.007$, $B(\phi\to K_LK_S) = 0.336\pm 0.002\pm 0.006$, $B(\phi\to\pi^+\pi^-\pi^0) = 0.155\pm 0.002\pm 0.005$, $B(\phi\to\eta\gamma) = 0.0138\pm 0.0002\pm 0.0002$.Comment: 14 pages, 3 figure

GAS DYNAMIC DESIGN OF SUBSONIC NOZZLE IN TURBOFAN ENGINE

This paper is done to research gas-dynemic condition of jet pipe. For this purpose engine Trent 1000 was chosen as prototipe. After calculation we get such parameters as velocitys, streamlines, Mach number and others. Resultsanalisyshasshownthatconstructionshould be changet in order to reach needed parameters