bluuebunny/crossref_metadata_2025 huggingface dataset:
Local structure of amorphous (GeTe)-=SUB=-x-=/SUB=-(Sb-=SUB=-2-=/SUB=-Te-=SUB=-3-=/SUB=-) films
Authors: Marchenko A.V.  , Terukov E.I.  , Nasredinov F. S.  , Petrushin Yu. A.  , Seregin P. P.
Published: March 2023

By the method of Messbauer spectroscopy on the isotope 119Sn, it was shown that tetravalent germanium atoms in amorphous films (GeTe)x(Sb2Te3) (where x=0.5, 1, 2, 3) form a tetrahedral system of chemical bonds, and in their local environment there are mainly tellurium atoms. In crystalline films (GeTe)x(Sb2Te3) is divalent hexoordinated germanium at positions 4 b of the NaCl type crystal lattice. By the meth-od of Messbauer spectroscopy on 121Sb and 125Te atoms, it was shown that the amorphization of (GeTe)x(Sb2Te3) films does not change the lo-cal environment of antimony and tellurium atoms Keywords: amorphous films, phase memory, Messbauer spectroscopy.
Dyakonov Surface Waves at the Boundary of Anisotropic Biaxial Crystals
Authors: Zakharchenko M. V.  , Glinskii G. F.
Published: March 2023

A general approach to analysis of Dyakonov surface waves at the interfaces of anisotropic biaxial crystals is proposed, taking into account arbitrary spatial orientation of the media tensors principal axes. This approach is based on the operator representation of macroscopic Maxwell equations corresponding to the quantum-mechanical equations for photon states in an inhomogeneous anisotropic media. Surface wave dispersion law is investigated in the most general case. It is established that the interface eigenmode dispersion is closely related to the dispersion of bulk waves in the partnering media, which is a specific feature of Dyakonov waves. The electromagnetic field spatial distribution is investigated in the direction orthogonal to the boundary plane. The surface wave angular existence domain is determined. It's dependencies on the rotation angles of the media optical axes are studied as well. Keywords: electromagnetic surface waves, interface photon states, anisotropic media, biaxial materials.
Quantum magnetometer based on cross-relaxation resonances in ensembles of NV-centers in diamond
Authors: Akhmedzhanov R. A.  , Gushchin L. A.  , Zelensky I. V.  , Kupaev A.V.  , Nizov V. A.  , Nizov N. A.  , Sobgayda D. A.
Published: March 2023

We create a working model of a magnetometer of a new type that is based on using cross-relaxation resonances in ensembles of NV-centers in diamond. This type of magnetometer does not require microwave radiation. For a sensor made out of a 300 micron diamond we demonstrate the magnetic field sensitivity of around 18 nT/Hz1/2. Keywords: cross-relaxation, NV-center, quantum magnetometer.
About the force of electrostatic interaction between two spheroidal macroparticles in the Poisson-Boltzmann model
Authors: Grashchenkov S. I.
Published: March 2023

Electrostatic interaction of two charged spheroidal macroparticles is analyzed within the linearized Poisson-Botzmann model.Interparticle forces are calculated through finite-element method in the regimes of weak and moderate screening with constant surface potentials in the absence of external field. Keywords: linearized Poisson-Botzmann model, two charged macroparticles, spheroidal macroparticles, colloidal particles, dusty plasmas.
Advanced Hall Magnetometer with improved performance
Authors: Kh. R. Rostami
Published: March 2023

A sharp jump in the magnetic response near the first critical twins magnetic field Hic1 was generated under the combined action of a constant biased and a local oscillating damped magnetic fields on the surface of the YBa2Cu3O7-x epitaxial film. The possibility of increasing due to this jump the sensitivity of a standard Hall magnetometer from ~2.5·10-3 Gs/Hz1/2 to ~8·10-7 Gs/Hz1/2 in the frequency range ~1 kHz has been demonstrated. The range of the measured magnetic fields of the magnetometer was extended to the region of weak fields ~(8·10-7-2.5·10-3) Oe, while maintaining the accuracy and linearity of the order of ~0.01%. To increase the sensitivity, linearity and noise sustainability the beginning of the operating point of the magnetometer was shifted to the twins values Hic1. The increased spatial resolution of the magnetometer, determined by the linear dimensions of the YBa2Cu3O7-x film twins, was provided by an increase in the total magnetic field directed perpendicular to the film surfaces and the Hall transducer and reached ~300 nm. Keywords: the twin high temperature superconductor, the density jump of the trapped magnetic flux, biased magnetic field, oscillating damped local magnetic bias field, two-stage Hall magnetometer.
Residual stresses at the interface between carrier tape and YSZ layer in manufacture of 2G HTS wires
Authors: Irodova A. V.  , Golovkova E. A.  , Kondratiev O. A.  , Kruglov V. S.  , Krylov V. E.  , Tikhomirov S. A.  , Shavkin S. V.
Published: March 2023

Using X-ray diffraction, there were determined the residual stresses on the surface of the AISI 310S stainless steel carrier tape used in manufacture of the second generation high temperature superconducting (2G HTS) wires at the National Research Center "Kurchatov Institute", from delivery to deposition of the main buffer layer YSZ between the tape and the superconducting layer, and the residual stress in the buffer layer YSZ itself. The compressive stress of -0.8 GPa induced by rolling was found on the surface of the tape as-delivered. During processing, it varies from -0.5 to -1.1 GPa. At each stage, its depth distribution was found down to 10 μm, and the residual stresses caused by processing were determined. The residual stress in the YSZ layer deposited using the ABAD technology is compressive and amounts to -3.29 GPa. The layer has a defective single-crystal structure in type to radiation swelling with the unstressed lattice period of 5.1820 Angstrem, 0.9% larger than in ordinary crystal. The results obtained are in agreement with the data of the earlier neutron diffraction study of residual stresses inside the carrier tape. Keywords: residual stress, 2G HTS wires, AISI 310S tape, YSZ layer, YSZ crystal structure, X-ray diffraction.
Fourier analysis of modes of microstructured optical fibers
Authors: Sotsky A B.  , Ponkratov D. V.  , Sotskaya L. I.
Published: March 2023

An vectorial mode solver for microstructured optical fibers based on the representation of the longitudinal components of the mode fields at the interfaces of media in the fiber cross section by Fourier series in angular variables is formulated. The coefficients of the series are found from a homogeneous algebraic system solved by the reduction method. The matrix elements of the system are determined on the basis of the Green's theorem, which is considered in the internal and external regions of the fiber cross section and the inclusions that form the microstructure. The elements are represented by regular integrals, i.e. difficulties associated with the singularities of the Green's functions are absent. The applicability of the approach is limited only by the requirement that the contours of the inclusions and the outer boundary of the fiber are described by single-valued functions of the angular variables. In the special case of a circular dielectric waveguide, the method gives an exact analytical solution of the waveguide problem. Estimates are obtained for the internal convergence of the method in computing the modes of a dielectric elliptical waveguide and microstructural fibers with elliptical inclusions. It is established that the attenuation coefficients of the modes caused by radiation leakage from the fiber core are significantly affected by both the internal microstructure and the outer fiber boundary. Keywords: microstructured fiber, Green's theorem, Fourier series, internal convergence, leaky modes.
Modeling of optical concentrators for the upgraded camera of the TAIGA-IACT Cherenkov gamma-ray telescope
Authors: Antonov A. S.  , Bogdanov A. A.  , Krassiltchikov A. M.  , Kholupenko E. E.
Published: March 2023

A quantitative simulation of a system of optical concentrators based on Winston's hexagonal cones, intended for the registration camera of the TAIGA-IACT Cherenkov gamma-ray telescope, has been performed. The data on the transmission of the cones are obtained; the distributions of the photon flux intensity in the plane of the detector are given. On the basis of the results obtained, an optimal configuration of optical concentrators is proposed, taking into account the design features of the mount, mirror and TAIGA-IACT camera, as well as the features of its new detector units. Keywords: Cherenkov gamma-ray telescope, TAIGA-IACT, Winston cone, numerical simulation.
On the origin of chains of cavities in the rotating flow between cylinders
Authors: Amromin E.L.
Published: March 2023

Cavitation between rotating and immobile cylinders appears in the form of a regular chain of bubbles. The bubble sizes are practically equal, as well as the distances between the bubbles and their azimuthal locations. Though such a form of cavitation has been observed in numerous experiments (in particular, in the experiments with bearings), its nature was not clarified. The presented analysis shows that breakdown of the flow axial symmetry due to displacement of the axis of one of cylinders leads to the regular wave-similar three-dimensional flow perturbations. Their "wavelength" is predetermined by the minimal gap between cylinders. Though the flow between cylinders is not curl-free, these perturbations can be determined with the use of a velocity potential. Keywords: Cavitation, circular cylinders, misaligned cylinders, non-viscous flow.
Shock-wave polymorphic transition in porous graphite
Authors: Kinelovskii S. A.
Published: March 2023

For the polymorphic transformation of porous graphite in the shock, the previously proposed model linking the process of graphite phase transition with a change in the elastic energy of a substance has been tested. It is shown that the model plausibly describes the experimental results outside the transition zone in a fairly wide range of changes in the porosity of samples with their different initial structure. It is discussed how the model under consideration changes the currently existing ideas about the thermodynamics of the polymorphic transition of matter in a shock wave. Keywords: polymorphism, shock wave, porosity, graphite, diamond, phase transition.
Optimization of mass separators
Authors: Lukashevich V.V.
Published: March 2023

The optimization of separator masses in this paper is based on the realization of the linearity of the system under study and the consequences of Liouville's theorem. The properties of several mass separators with an ion energy of 30 keV and a beam emittance of 4 mm·mrad are considered. Focusing is provided by an aberration-free lens and a magnetic corrector. Phase diagrams along the beam path are in the form of parallelograms, which indicates the absence of geometric aberrations. For each of the separators, the resolution calculated in the linear approximation coincides with the simulation results. It is shown that a mass separator based on a magnet with a rotation angle of 54.7o has a resolution of about 5000, and a separator based on two magnets with a rotation angle of 45o and 90o, respectively, has a resolution of 14 000-15 000. Keywords: ion optics, emittance, lenses, phase diagram, aberrations.
Highly sensitive express nonlinear optical diagnostics of the crystalline state of heterostructures such as sphalerite
Authors: Stupak M. F.  , Mikhailov N. N.  , Dvoretsky S. A.  , Makarov S. N.  , Yelesin A. G.  , Verhoglyad A. G.
Published: March 2023

The characteristics of a highly sensitive express bench for nonlinear optical diagnosis of crystalline structures such as sphalerite by generation of the second harmonica are presented. The analysis of the possibilities of quantitative and qualitative characterization of the features of the crystalline parameters of the layers of heteroepitaxial structures CdxHg1-xTe on substrates from GaAs with orientation (013) was carried out. The results were obtained by deviations of orientation in layers from the orientation of the substrate, which arose during the epitaxy, to determine the existence of stresses. The high sensitivity of the bench revealed the presence/absence of micro-particles with a disordered crystalline structure. Experimental results of reversible modification of the "in situ" crystalline state of CdxHg1-xTe structures with short-term local radiation exposure of high power laser radiation are given. New experimental data have been presented showing that the components of the nonlineaic susceptibility tensor chixyz(ω) of the crystalline structure of CdxHg1-xTe depend on composition and are an order of magnitude larger than similar components of tensor in CdTe and GaAs. Keywords: sphalerite crystals, second harmonica, azimuth angular dependence, tensor of nonlinear susceptibility, tensions, microparticle, radiation heating, heterostructures CdxHg1-xTe.
Ultrafast laser-induced control of magnetic anisotropy in nanostructures
Authors: Kalashnikova A. M.  , Khokhlov N. E.  , Shelukhin L. A.  , Scherbakov A. V.
Published: March 2023

Employing short laser pulses with a duration below 100 fs for changing magnetic state of magnetically-ordered media has developed into a distinct branch of magnetism femtomagnetism which aims at controlling magnetization at ultimately short timescales. Among plethora of femtomagnetic phenomena, there is a class related to impact of femtosecond pulses on magnetic anisotropy of materials and nanostructures which defines orientation of magnetization, magnetic resonance frequencies and spin waves propagation. We present a review of main experimental results obtained in this field. We consider basic mechanisms responsible for a laser-induced change of various anisotropy types: magnetocrystalline, magnetoelastic, interfacial, shape anisotropy, and discuss specifics of these processes in magnetic metals and dielectrics. We consider several examples and describe features of magnetic anisotropy changes resulting from ultrafast laser-induced heating, impact of laser-induced dynamic and quasistatic strains and resonant excitation of electronic states. We also discuss perspectives of employing various mechanisms of laser-induced magnetic anisotropy change for enabling processes prospective for developing devices. We consider precessional magnetization switching for opto-magnetic information recording, generation of high-frequency strongly localized magnetic excitations and fields for magnetic nanotomography and hybrid magnonics, as well as controlling spin waves propagation for optically-reconfigurable magnonics. We further discuss opportunities which open up in studies of ultrafast magnetic anisotropy changes because of using short laser pulses in infrared and terahertz ranges. Keywords: magnetic anisotropy, femtosecond laser pulses, femtomagnetism, picosecond acoustics, magnetization precession, spin waves, magnetization switching, magnon-phonon coupling.
Investigation of the mechanism of switching a short vacuum gap using an auxiliary spark discharce
Authors: Davydov S. G.  , Dolgov A. N.  , Kozlov A. A.  , Yakubov R. Kh.
Published: March 2023

The ionization of a rarefied gas in a short gap by a stream of short-wave radiation and fast electrons from the plasma of an auxiliary spark discharge along the dielectric surface is detected, sufficient to initiate an arc discharge in the gap. The density of the ionizing flow of particles and radiation determines the delay time of the switching gap in relation to the start of the auxiliary discharge. With an increase in the initial concentration of free electrons in the main discharge gap, the transition time to an arc discharge is reduced, due to the development of instabilities. Keywords: plasma, arc discharge, spark discharge, ionization, instability.
Modified theory of coupled waves and a numerical method for the analysis of Bragg mirrors with an arbitrary refractive index profil
Authors: Masterov R. A.  , Karpov S. Yu.
Published: March 2023

An analytical and effective numerical approach to the analysis of the optical characteristics of Bragg mirrors with an arbitrary refractive index profile is developed. Analytical expressions obtained using the modified theory of coupled waves for the coefficients of reflection / transmission of light from through the BM with high accuracy predict its main characteristics at both low and high contrast of the refractive index. The hybrid numerical method includes the numerical calculation of the transfer matrix for one period of the knowledge base and its analytical multiplication for an arbitrary number of periods. The developed methods are applied to the analysis of the properties of practically important BMs made on the basis of sprayed pairs of Ta2O5/SiO2 dielectrics, Group III nitrides and arsenides. The characteristics of the knowledge base with smooth (gradient) interfaces are considered in detail. Keywords: vertically emitting lasers, reflection coefficient, reflection bandwidth.
Investigation of the characteristics of the InGaAs/InAlGaAs superlattice for 1300 nm range vertical-cavity surface-emitting lasers
Authors: Blokhin S.A.  , Babichev A. V.  , Gladyshev A. G.  , Karachinsky L. Ya.  , Novikov I. I.  , Blokhin A.A.  , Bobrov M. A.  , Maleev N.A.  , Kuzmenkov A.G.  , Nadtochiy A.M.  , Nevedomskiy V. N.  , Andryushkin V.V.  , Rochas S. S.  , Denisov D. V.  , Voropaev K. O.  , Zhumaeva I.O.  , Ustinov V. M.  , Egorov А. Yu.  , Bougrov V.E.
Published: March 2023

X-ray structural analysis and photoluminescence spectroscopy techniques were used to study heterostructures based on InGaAs/InAlGaAs superlattice for active regions of 1300 nm range lasers grown by molecular beam epitaxy. It is shown that the grown heterostructures have a high crystal quality. The perpendicular lattice mismatch of the average crystal lattice constant of the InGaAs/InAlGaAs superlattice with respect to the crystal lattice constant of the InP substrate is estimated at ~+0.01%. An analysis of the photoluminescence spectra made it possible to conclude that the contribution of Auger recombination is insignificant in the studied range of excitation power density. Studies of vertical-cavity surface-emitting lasers with an active region based on the InGaAs/InAlGaAs superlattice made it possible to estimate the gain coefficient at a level of 650 cm-1 for the standard logarithmic approximation of the dependence of the gain on the current density. The transparency current density of the laser was 400-630 A/cm2, which is comparable to the record low values for the case of highly strained InGaAs-GaAs and InGaAsN-GaAs quantum wells in the spectral ranges of 1300 nm, respectively. Keywords: superlattice, vertical-cavity surface-emitting laser, optical gain.
Electrical stimulation of human dermal fibroblasts on conducting matrix
Authors: Kolbe K. A.  , Shishov M. A.  , Sapurina I. Yu.  , Smirnova N. V.  , Kodolova-Chukhontseva V. V.  , Dresvyanina E. N.  , Kamalov A. M.  , Yudin V.E
Published: March 2023

Conducting composite based on biocompatible chitosan and single wall carbon nanotubes was used as a matrix for electrical stimulation of human fibroblasts. Parameters of ionic and electronic currents passing through the matrix upon applying cyclic potentials (±100 mV) were studied; the scaffold demonstrated high stability in the course of prolonged electric cycling. It was shown that preliminary electrical stimulation facilitated proliferative activity of human dermal fibroblasts in comparison to that of intact cells. Keywords: chitosan/carbon nanotube composite, electrical stimulation, dermal fibroblasts.
The results of measuring the emissivity of a number of metals of the copper subgroup at transition temperatures through the melting point
Authors: Kosenkov D. V.  , Sagadeev V. V.
Published: March 2023

The emissivity of copper, silver and gold has been experimentally determined in the temperature range, including the solid-liquid phase transition. The measurement error ranged from 5 to 8%. Keywords: experimental cell, thermal radiation, phase transition, the metal under study.
Peculiarities of breakdown and current development in a pulsed open" discharge
Authors: Bokhan P. A.  , Glubokov N.A.  , Gugin P.P.  , Zakrevsky D.E.  , Lavrukhin M.A.
Published: March 2023

We present the results of a study of the breakdown characteristics of a planar "open" discharge in helium when excited by pulses with nanosecond rising edge. It is demonstrated that the development of the discharge is characterized by considerably larger values of the reduced electric field strength than in the avalanche discharge. A similarity criterion was obtained for discharges with a predominance of the photoemission mechanism of electron generation, according to which the rate of discharge development is proportional to the square of the working gas pressure. Keywords: nanosecond gas discharge, breakdown, delay time, similarity condition.
Investigation of the features of electronic spectrum of quantum dots in narrow-gap semiconductors
Authors: Kabanov V. F.  , Mikhailov A. I.  , Gavrikov M. V.
Published: March 2023

Samples with quantum dots (QDs) of narrow-gap semiconductors of the A3B5 group (indium antimonide) and the A2B6 group (mercury selenide) have been studied. The absorption spectra of the investigated QDs are analyzed and the correspondence of the maxima in the spectral characteristics to the model representations of the calculated electronic energy spectrum for this materials is assessed. It is concluded that used model representations requires refinement, primarily due to the fact that studied objects are nanocrystals with complex geometry. Keywords: quantum dots, indium antimonide, mercury selenide, electronic energy spectrum.
Phase transitions Co-C nanocomposite at heating
Authors: Spivak L. V.  , Sosunov A. V.  , Shchepina N. E.
Published: March 2023

Differential scanning calorimetry was used to study the Co-C nanocomposite, which is an array of ultrathin carbon nanocages encapsulated cobalt nanoparticles. The activation energy of the α-> β transformation of the nanocomposite and the value of its endothermic effect have been estimated. Thermal effect is much greater than those values that correspond to the observation conditions for α->β transformations in massive cobalt samples. The idea was put forward that transitional transformation is assumed by a non-diffusion, massive mechanism. Keywords: phase transitions, carbon nanocages, cobalt, activation energy.
Numerical and experimental study of the effect of gas blowing/suction through a perforated surface on the boundary layer at a supersonic Mach number
Authors: Polivanov P. A.
Published: March 2023

In this paper a numerical and experimental study of the effect of blowing/suction through a perforated surface on a turbulent boundary layer at a Mach number M=1.4 was carried out. Most of the calculations were performed by Reynolds-averaged Navier-Stokes equations with the kappa-ω SST turbulence model. The calculated geometry completely repeated the experimental one including the perforated surface. The numerical data were compared with experimental measurements obtained by the PIV method. Analysis of the data made it possible to find the limits of applicability of the numerical method for the flow under study. Keywords: supersonic flow, gas blowing/suction through a perforated surface, boundary layer, turbulence model kappa-ω SST, PIV method.
Effect of annealing temperature on the kinetics of aluminum-induced crystallization of amorphous silicon suboxide thin films
Authors: Merkulova I. E.  , Zamchiy A. O.  , Lunev N. A.  , Konstantinov V. O.  , Baranov E. A.
Published: March 2023

In this work, the kinetics of aluminum-induced crystallization (AIC) of non-stoichiometric silicon oxide a-SiO0.25 was investigated for the case of annealing at temperatures of 370, 385 and 400oC, as a result of which thin films of polycrystalline silicon were obtained. It is shown that, at low annealing temperatures, the surface morphology of the crystalline material is represented by dendritic structures corresponding to the growth model with diffusion-limited aggregation. In addition, with increasing annealing temperature, the nucleation density increases from 3 to 53 mm-2. From the Arrhenius plot, the activation energy of the a-SiO0.25 AIC was obtained for the first time and appeared to be 3.7± 0.4 eV. Keywords: aluminum-induced crystallization, silicon suboxide thin films, polycrystalline silicon, activation energy.
Critical analysis of the work "Experiment to create a radio communication channel in the marine environment"
Authors: Simunin M. M.
Published: March 2023

The article "Experiment to create a radio communication channel in the marine environment" (authors: A.K. Tomilin, A.F. Lukin, A.N. Gulkov) published in Journal "Technical Physics Letters" (2021, vol. 47, Issue 11) is analyzed from the standpoint of classical physics. The organization of the experiment in the mentioned publication, interpretation of its results, and theory underlying the work are criticized. The proposed material is a methodological commentary and is intended to form consistent approaches to be used in studying and interpreting further works on creation of radio communication channels. Keywords: Radio communication in the marine environment, electromagnetic waves, methodological notes
Features of the keyhole evolution during deep penetration of metals by laser radiation
Authors: Seidgazov R. D.  , Mirzade F. Kh.
Published: March 2023

The paper presents the results of fast detection of the keyhole formation in titanium under point exposure to laser radiation. The fact has been established that the keyhole evolution ends with a collapse even before the cessation of the action (switching off) of the continuous laser radiation. Keywords: deep penetration, keyhole, collapse, laser radiation.
Mushroom mesa structure for InAlAs-InGaAs avalanche photodiodes
Authors: Maleev N.A.  , Kuzmenkov A.G.  , Kulagina M.M.  , Vasyl’ev A. P.  , Blokhin S. A.  , Troshkov S.I.  , Nashchekin A.V.  , Bobrov M. A.  , Blokhin A. A.  , Voropaev K.O.  , Bugrov V.E.  , Ustinov V.M.
Published: March 2023

Mushroom mesa structure for InAlAs/InGaAs avalanche photodiodes (APD) was proposed and investigated. APD heterostructrures were grown by molecular-beam epitaxy. Fabricated APDs with the sensitive area diameter of about 30 micron were passivated by SiN deposition and demonstrated avalanche breakdown voltage Vbr 70-80 V. At the applied bias of 0.9 Vbr, the dark current was 75-200 nA. The single-mode coupled APDs demonstrated responsivity at a gain of unity higher than 0.5A/W at 1550 nm. Keywords: avalanche photodiode, InAlAs/InGaAs, mesa structure, dark current.
Investigation of the photoelectric characteristics of GaAs solar cells with different InGaAs quantum dot array positioning in the i-region.
Authors: Salii R. A.  , Mintairov M. A.  , Mintairov S. A.  , Nakhimovich M. V.  , Shvarts M. Z.  , Kalyuzhnyy N. A.
Published: March 2023

The effect of positioning of the In0.8Ga0.2As quantum dots (QDs) array in the i-region of the solar cell (SC) on its photogenerated current and dark saturation currents, which determine the device operating voltage, have been investigated. It was found out that the indicated photoelectric characteristics depend on the location of the QD array relative to the electric field of the p-n junction. The displacement of the QD array to the boundary of the weakly doped base leads to a decrease in the photogenerated current. But at the same time, the voltage drop effect, which is well-known for nanoheterostructural SC, is minimal. Keywords: solar cells, quantum dots, dark saturation current
Capillary-wave warp-drive
Authors: Aleksandrov V. A.
Published: March 2023

The generation of surface water flow in channels with sources and resonators of capillary oscillations is detected and investigated. Moving devices with a capillary-wave accelerator of the surface fluid flow are demonstrated. The surface flow of liquid in the channel is generated due to the local deformation of the liquid surface by capillary vibrations and the formation of an excess liquid surface on average near the source and the transport of this surface by waves. Keywords: capillary oscillations and waves, surface liquid flow, channel.
Electrophysical and thermal parameters of the atmospheric pressure plasma jet in helium excited by sinusoidal and pulsed voltages
Authors: Gugin P.P.  , Zakrevsky D.E.  , Milakhina E.V.
Published: March 2023

Comparative studies of cold plasma jet of generation at atmospheric pressure in helium excited by sinusoidal and unipolar positive pulses voltage at 2-6 kV for medical applications were carried out. It has been shown that the achieved parameters are identical, but the absence of the effect of frequency self-organization of streamer breakdown leading to irregularity in streamer propagation under pulse excitation makes it preferable in biophysical experiments. A limiting factor for plasma jet exposure is the achievable target temperature, which can be reduced by limiting the current duration. Keywords: cold plasma jet, excitation by sinusoidal and pulsed voltage, temperature.
Association between xanthinoxidase activity andparameters of glucose homeostasis in patients with type 2 diabetes mellitus
Authors: Karachentsev Yu. , Cherniaieva A. , Mykytyuk M. , Sergienko L.
Published: March 2023

Background. The purpose of the study is to determine the associations between clinical and anthropometric parameters, glucose homeostasis and serum xanthinoxidase (XO) activity in patients with type 2 diabetes mellitus (T2DM) taking into account gender, glycemic control and serum XO activity. Materials and methods. One hundred and twenty-five T2DM patients aged 34 to 81 years were examined, with an average age of 58.9±9.4 years, disease duration from 1 month to 29 years (average of 8.9±6.6 years). The age of patients at the time of the disease manifestation in the general sample was from 29 to 71 years, on average 50.6±9.1 years. Results. The authors have found a nonlinear dependence of serum XO activity on fasting insulin concentration in patients with T2DM in the total sample, described by the multiplicative model (r=0.45; p=0.001). Serum XO activity in patients with T2DM in the general sample increases with adaptive increase in secretory activity of β-cells on an empty stomach according to the HOMA_β%. Serum ХO activity was highest in T2DM patients with low fasting insulin sensitivity (HOMA_S% < 50%). In addition, it has been determined that the serum ХО activity in the subjects is nonlinearly associated with the QUICKI (r=–0.35; p=0.016) and Caro indices (r=–0.40; p=0.007). We have found a nonlinear dependence of serum XO activity on fasting insulin (r=0.50; p=0.08), HOMA_β% (r=–0.53; p=0.06), HOMA_S% (r=–0.48; p=0.09), HOMA-IR (r=–0.48; p=0.09) in men with optimal glycemic control (HbA1c < 7.5%) at the trend level and Caro (r=–0.64; p=0.02). In women of this group, there was a nonlinear dependence of serum XO activity on fasting insulin (r=0.56; p=0.004), HOMA_β% (r=0.56; p=0.003), HOMA_S% (r=–0.54; p=0.005), HOMA-IR (r=0.54; p=0.005), QUICKI (r=–0.50; p=0.01) and Caro (r=–0.61; p=0.003). Conclusions. In patients with T2DM, the serum uric acid is linearly associated with the level of serum XO activity, which determines 34% of its variability. In patients with T2DM, regardless of the state of glycemic control, serum XO activity is nonlinearly associated with parameters characterizing the state of glucose homeostasis (fasting insulin, HOMA_S%, HOMA_β%, QUICKI and Caro indices). Predictors of high serum XO activity in patients with T2DM are the level of postprandial blood glucose (t=–3.53; p=0.004) and serum uric acid (t=4.73; p=0.0005).
Involvement of the vitamin D receptor gene in the development of idiopathic short stature
Authors: Bolshova O.V. , Ryznychuk M.O. , Kvachenyuk D.A.
Published: March 2023

Background. The vitamin D receptor (VDR) gene is localized in the chromosome 12 (region 12q13). Its polymorphic variants BsmI and FokI are the most promising in clinical and diagnostic terms. During normal ontogenesis, the VDR gene affects the total bone content in the body and its resulting length determined by the development of the skeleton. The aim of the study was to assess genotypic features in children with idiopathic short stature. Materials and methods. Determination of the BsmI polymorphism in the VDR gene (rs1544410) was performed by polymerase chain reaction followed by analysis of the length of restriction fragments when detected by agarose gel electrophoresis in 18 prepubertal children with idiopathic short stature. Results. In the group of children with idiopathic short stature, the proportion of the GG genotype is four times higher than in the control group. In children of the G/A heterozygotes, the risk of idiopathic short stature is significantly high (odds ratio (OR)=6.00; 95% confidence interval (CI) 2.06–17.48; p<0.01); in the G/G variant, it is high but not significant (OR=4.54; 95% CI 0.70–29.31; p=0.11). Patients with the AA genotype were three times less than in the control group, indicating that the AA homozygotes have a threefold reduction in the risk of idiopathic short stature compared to an empirical risk. The frequency of the G allele in patients (qG=0.444) is almost three times higher than in the group of healthy individuals (qG=0.152), indicating that the carriage of the G allele of the rs1544410 BsmI polymorphic locus of the VDR gene is significantly associated with the risk of developing idiopathic short stature (OR=4.46; 95% CI 3.60–5.51; p<0.001). Conclusions. In children with the G/A and G/G genotypes, the risk of idiopathic short stature increases, and the presence of the A/A genotype is a protective polymorphism against idiopathic short stature. Carriage of the G allele of the rs1544410 BsmI polymorphic locus of the VDR gene is associated with the risk of idiopathic short stature, despite the almost perfect distribution of genotypes.
Hormonal imbalance in patients with chronic renal failure in the pre-dialysis and dialysis periods (part1)
Authors: Katerenchuk I.P. , Rustamyan S.T. , Talash V.V. , Yarmola T.I.
Published: March 2023

The review describes the problem of studying progressive changes of hormones concentrations (parathyroid hormone, insulin, somatotropin, prolactin) in patients with chronic renal failure on the pre-dialysis and dialysis stages. The pathogenetic relationships between kidney function deterioration and hormone concentrations as well as changes of their biological effects were evaluated. Parathyroid hormone is considered as an uraemic toxin, since its concentration in the blood begins to increase when the glomerular filtration rate decreases below 50 ml/min. All stages of chronic kidney disease are accompanied by disorders of calcium-phosphorus metabolism. Prolonged excess of parathyroid hormone leads to bone loss and to the progression to secondary hyperparathyroidism that is a frequent complication in patients with the later stages of chronic renal failure and, especially, in those on dialysis treatment. The elevation of insulin level in chronic renal failure is the consequence of progressive decrease in glomerular filtration rate and insulin excretion by proximal tubules. So, it results in insulin half-life prolongation. Long-term dialysis therapy eliminates factors that reduce the degradation of insulin by extrarenal tissues, which results in an improvement of their insulin sensitivity. Experimental and clinical studies have shown that an excess of somatotropin can adversely affect the kidneys that leads to glomerular hyperfiltration and the progression to glomerulosclerosis. The risk of possible side effects on kidneys should be taken into account when prescribing recombinant human insulin-like growth factor. The prolactin concentration is usually increased in chronic kidney disease due to reduced clearance and increased secretion. Hyperprolactinemia manifests as galactorrhea and hypogonadism. Dialysis therapy can’t normalize the increased concentration of prolactin. Modern options for pathogenetic treatment of endocrine disorders in patients with chronic renal failure are outlined in this article. It was found that kidneys play an important role in regulating hormones concentrations in the blood. Endocrine disorders are one of the most important components of the uraemic syndrome, which requires further clinical studies, aimed on the searching of better treatment strategies and prevention of hormonal imbalance on the pre-dialysis and dialysis stages of chronic kidney disease.
IN VITRO ASSESSMENT OF NATURAL HERBAL EXTRACTS FOR ANTIMICROBIAL ACTIVITY
Authors: CHALIVENDRA PALLAVI , GANJIKUNTA RAVINDRA KUMAR , RAO K. UMAMAHESWARA , PULLAKANAM RI PHANI TEJASWI
Published: March 2023

Objective: Herbal medicine is still the mainstay of about 75-80% of the whole population, and the major part of traditional therapy involves the use of plant extract and their active constituents against infectious pathogens. Objective: The study aimed to investigate in vitro antibacterial activity of extracts from some medicinal plants against the most common microbial pathogens including MDR bacteria.

Methods: The processing of plant materials was performed with the washing, drying and grinding of collected plant materials. The plant extracts were prepared by mixing 10 g of powder to 150 ml of ethanol solvent for 5 h at room temperature and sonicated for 15 min; for prepared test samples under laboratory conditions, the air-dried samples were mixed with the respective solvent (1:15 w/v) for 72 h at room temperature with occasional and then filtered through Whattman filter paper No.1. The obtained extract was freed from the solvent by evaporation under reduced pressure and then resuspended in the appropriate solvent to make the solution of known concentration of 10-50 mg/ml. The extract was stored at 4 °C in airtight glass bottle for the antibacterial assay using the Agar-well diffusion method. Ciprofloxacin was used as a control antibiotic.

Results: The growth of K. pneumoniae, Proteus mirabilis, P. aeruginosa and E. coli were inhibited better with the plant extract Tinospora cardifolia leaves than ciprofloxacin antibiotic. Coagulase-negative Staphylococci was inhibited greatly with Costus igneus leaf extract. The growth of Enterococcus faecalic was inhibited significantly with Tridax procumbens leaf extract than ciprofloxacin.

Conclusion: The present study indicates Tridax procumbens, T. cordifolia and Costus igneus methanolic leaf extracts were showed strong antimicrobial activity against all the tested cultures. They were rich in primary and secondary constituents. Most of the biologically active phytochemicals were present in methanolic extract. The tested plant extracts were more efficient than standard antibiotic ciprofloxacin used in the current study.
ISOLATION OF MULTI DRUG RESISTANT BACTERIA FROM BORE WATER SAMPLES IN AND AROUND VISAKHAPATNAM
Authors: SIRISHA TIRUVAIPATI , SASAPU SWAPNA , VIJAYALAKSHMI PAYALA , KUMARI PILLI HEMA PRAKASH
Published: March 2023

Objective: The aim of the present study was to determine the levels of groundwater contamination by isolating total coliforms, fecal coliforms, and bacterial pathogens.

Methods: A total of 32 water samples, comprising 5 samples from each GVMC urban area zone, Visakhapatnam were randomly collected from different areas. Evaluation of Total and fecal coliform counts was done by using multiple-tube fermentation technique and were reported as the most probable number (MPN) of organisms present per 100 ml of sample.

Results: The samples collected from the zones Yendada (zone I), Marripalem (zone IV), Chinna musidiwada (zone VI) showed the highest total and fecal coliform counts (MPN>180). Nearly 30 samples (94%) yielded bacterial isolates. Among the isolates Pseudomonas spp. showed highest susceptibility to cefepime and imipenem antibiotics. All the microorganisms isolated were multidrug resistant with a multidrug antibiotic resistant index more than 0.2.

Conclusion: These multidrug-resistant (MDR) organisms are considered as a major threat to the public health and should receive more attention.
MEMORY ENHANCING ACTIVITY OF MADHUCA LONGIFOLIA ETHANOLIC LEAF EXTRACT (FLAVONOID FRACTION) AND ITS HPTLC
Authors: KHARE PRAGATI , KHARE NOOPUR
Published: March 2023

Objective: The present study aimed at investigating the protective role of Madhuca longifolia ethanolic leaf extract flavonoid fraction against colchicine induced cognitive dysfunction and oxidative damage in swiss albino mice and to estimate the biochemical alterations in mice brain. HPTLC, total flavonoid and total phenols were also estimated in the study.

Methods: The analysis was conducted on a colchicine-induced model for 28 d. Morris water maze and passive avoidance paradigm were used for conducting behavioral experiments, while biochemical parameters such as nitric oxide and glutathione were also estimated. Swiss albino mice (48) were apportioned into eight sets, each consisting of six mice. ANOVA (one-way) was utilized and then followed by the Dunnett’s test and finally outcomes were analyzed.

Results: The total flavonoids content in Madhuca longifolia leaves was found to be (14.17±0.56 QE and 21.24±0.94 RE mg/g of dry material) and total phenolic compounds were 299.32±2.73 mg/g of dry material. Madhuca longifolia leaf extract indicated a substantial reduction in escape latency of mice in morris water maze. The transfer latency of mice in passive avoidance model showed a substantial increase.

Conclusion: The Madhuca longifolia leaf extract presented a substantial increase (P<0.001) in GSH intensities and a major decline (P<0.001) in total protein, NO and AChE. Madhuca longifolia has neuroprotective effect against memory damage caused by colchicine.
The Psychologist’s Role in the Process of Listening to Children Victims of Sexual Violence in Legal Proceedings
Authors: Pereira Lila Dara de Barros
Published: March 2023

This work presents a set of interpretations made by the psychologist regarding the procedure for listening to children who are victims of sexual violence in legal proceedings based on the Doctrine of Integral Protection of the child. Documental surveys were carried out on the procedures for taking special statements from children in legal proceedings. Under the light of Winnicott's theory of emotional development, based on academic experience and extension activities, a personalized and dynamic qualitative method of investigation, essentially constructive-interpretative, was used to interpret the listening procedures. The result demonstrates that the discussion of the theme is recent in the world and that the biggest obstacle to a consensus regarding a procedure that proposes the non-revictimization of child victims of sexual violence in legal proceedings is to understand and study the limits of psychological science and legal science with a view to the Doctrine of Integral Protection.
Improved Productivity and Efficient Manufacturing Using Injection Molding and 3D Printing: A Review
Authors: Samah Smith , Borse Durgesh Y. , Sulakhe Vishal N.
Published: March 2023

Abstract: With the use of injection molding and 3D printing, materials with complex shapes can be mass-produced with better productivity and quality working efficiency. Proper injection speed, temperature, pressure, and the right mold design are crucial in producing higher-quality products. In order to be competitive with regard to business and marketing in the manufacturing industries, engineers will need to boost productivity and maintain a high standard of quality with efficient manufacturing. This paper discusses the role of injection molding and 3D printing in improving productivity and enabling the efficient manufacturing of products. This study also makes an effort to review the various methods and procedures now in use for 3D printing and injection molding.
Multiple Disease Prediction System
Authors: Ture Tanmay , Sawant Amol , Singh Rohan , Patil Prof. Chetna
Published: March 2023

Abstract: There are number of hospitals in the world with advanced diagnostic equipment. But although having this equipment some patients cannot get proper treatments and may suffer to death. Main reason behind this is time, our medical systems lack time and it is not easy for them to manage time. With help of machine learning techniques we created project that identifies patients with major diseases like Heart disease, Kidney disease and Diabetes disease at early stage so that proper treatments can be given to them. We collected three datasets for three models from Kaggle [1], analyzed[2]them, cleaned them and choose best algorithm [3] for each dataset. We achieved 98.52% accuracy on heart disease prediction model [4], 98.73% accuracy on kidney disease prediction model [5], 80.55% accuracy on diabetes disease prediction model [6]. For all three models we used Random Forest algorithm [7] .At the end we created web application using Flask [8] for easy user interaction.
Судалгааны реакторыг дэмжих үндэсний дэд бүтцэд хийсэн урьчиилсан үнэлгээ
Authors: Г Цэмбэлмаа , Бя Мөнхбат , Н Норов
Published: March 2023

Энэ судалгааны ажлын зорилго нь Олон улсын Атомын Энергийн Агентлагийн арга зүйд тулгуурлан Монголын цөмийн анхны судалгааны реакторын төслийг дэмжих үндэсний цөмийн дэд бүтцийн зарми асуудалд өөрийн үнэлгээг хийж, Олон Улсын Атомын Энергийн Агентлагийн шаардлагуудтай харьцуулалт хийж цаашид хийгдэх шаардлагатай ажлуудын талаар зарим дүгнэлтүүдийг гаргасан.
Diagnostic approach to low back pain
Authors: RESORLU Hatice
Published: March 2023

Low back pain is an important cause of pain referrals in the primary care setting. Overall, 85% of initial admissions are considered to be nonspecific low back pain that resolves in a few weeks without the need for additional evaluation. Myofascial pain, lumbar disc herniation, spinal stenosis, facet joint and disc degeneration, and sacroiliac joint pathologies are common causes of mechanical low back pain. Non-mechanical low back pain includes infections of the vertebral corpus and disc, malignant tumors and metastases, and inflammatory diseases. Red flag symptoms suggestive of serious diseases should be evaluated in all patients with low back pain, and the diagnosis process should be accelerated in patients with these symptoms. The so-called "yellow flags" associated with chronic low back pain include psychosocial factors. In the diagnosis process, pain relief is observed in patients with non-specific low back pain without the need for imaging methods. Laboratory tests and imaging methods can be used to distinguish other causes of low back pain.