Mathematical model and software for investigation of internal ballistic processes in high-speed projectile installations

This paper describes a software package that allows to explore the interior ballistics processes occurring in a shot scheme with bulk charges using propellant pasty substances at various loading schemes, etc. As a mathematical model, a model of a polydisperse mixture of non-deformable particles and a carrier gas phase is used in the quasi-one-dimensional approximation. Writing the equations of the mathematical model allows to use it to describe a broad class of interior ballistics processes. Features of the using approach are illustrated by calculating the ignition period for the charge of tubular propellant

Experimental hyperthermia: expression of proteins involved in the regulation of ovarian corpus luteum apoptosis in the acute and recovery periods

Background.Heat shock effects can initiate apoptosis of oocytes and corpus luteum cells in mammalian ovaries. During folliculogenesis, follicular apoptosis is regulated by Bcl-2 and BAX proteins which are key effectors of granular cell death. Mechanisms of disruption of the ovarian corpus luteum development under heat stress remain largely unclear.Aim of the research: to identify the expression features of anti-apoptotic Bad and proapoptotic Bcl-2 proteins in the rat ovarian luteocytes in the acute (by day 3) and recovery (by days 7 and 14) periods after a single exposure of experimental hyperthermia (EH) (rectal temperature 43.5 °C).Materials and methods. The expression of Bad and Bcl-2 was determined immunohistochemically using an indirect two-stage streptavidin-biotin method.Results. On day 3 after EH, the expression areas of both Bad and Bcl-2 increased 2-fold, but the ratio of Bcl-2/Bad areas did not change, indicating that the intensity of apoptosis along the mitochondrial pathway in luteocytes in the acute period was  maintained within physiological values. On day  7, the Bad and Bcl-2 expression areas remained at the level of day 3, but the Bcl-2/Bad index decreased, indicating the activation of the apoptosis internal pathway in the ovarian corpus luteum cells. By day 14, the protein expression areas decreased (Bad – by 1.7 times, Bcl-2 – by 3.2 times) compared to the acute period, and the Bcl-2/Bad index decreased by 2 times compared to the control and the acute period group.Conclusion. The observed predominance of proapoptotic Bad protein over antiapoptotic Bcl-2 in luteocytes on day 14 after EH indicates the anti-apoptotic protection violation, which leads to the apoptosis mitochondrial pathway activation of  the latter. A decrease in Bcl-2 expression can be regarded as a manifestation of the defective luteocytes removal mechanism and the body’s desire to normalize the ovarian-uterine cycle disrupted by high temperature exposure

Protection, transient stability and fault ride-through issues in distribution networks with dispersed generation

This paper describes the transient stability analysis of a 10 kV distribution network with wind generators, microturbines and CHP plants. The network being modeled in Matlab/Simulink takes into account detailed dynamic models of the generators. Fault simulations at various locations are investigated. For the studied cases, the critical clearing times are calculated. Some network parameters which influence transient stability are also observed. The compliance of DG protection to stability criteria requirements is further studied. The ride-through capability of the DG units is also investigated through transient stability analysis and the equivalent CCT-voltage dip curves are derived. It is concluded that during fault DG unit availability can be increased through modification of undervoltage protection requirements

Electronic structure and luminescence properties of Ca2Ge7O16:Dy3+

The present report represents an overview of the results of a combined experimental-computational study of electronic structure, thermoluminescence (TL) and afterglow properties of Ca2Ge7O16:Dy3+ synthesized for the first time. Afterglow curves of Ca2Ge7O16:Dy3+ at 575 nm showing persistent luminescence have been described in Becquerel law. The TL measurements reveal at least one TL band at 326 K and two luminescence bands at 475 and 535 nm. Persistent luminescence in Ca2Ge7O16:Dy3+ originates from relatively shallow charge traps with high probability of charge carriers recapture. The model of energy processes, configurations of traps and luminescence centers has been proposed with the aid of ab initio calculations performed using the LCAO approximation and several hybrid functionals

Synthesis and Luminescent Properties of Bismuth Titanates Bi1.6HoxTi2O7 – δ and Bi1.6Mg0.1HoxTi2O7 – δ

Abstract: Pyrochlores Bi1.6HoxTi2O7 – δ and Bi1.6Mg0.1Ho xTi2O7 – δ, where x = 0, 0.01, 0.05, and 0.1, and Bi1.5HoxTi2O7 – δ, where x = 0.25 and 0.5, have been synthesized and their structural, optical, and luminescence properties have been studied. As a result of analyzing the data obtained experimentally and the available theoretical data, it is shown that the intrinsic luminescence of the samples is due to the O2p ↔ Bi6p and Bi6s ↔ Bi6p electron transitions and the impurity luminescence is due to the f–f transitions in Ho3+ and the O2p → Ho3+ charge transfer. © 2019, Pleiades Publishing, Ltd.Russian Foundation for Basic Research, RFBR: 19-03-00642The reported study was funded by RFBR according to the research project 19-03-00642

Synthesis and characterization of semiconducting carbazole thin films

The main goal of this study is characteristics determination of synthesized or-ganic compounds for designing electronic components as organics diodes and transis-tors