bluuebunny/crossref_metadata_2025 huggingface dataset:
Manifestation of hydrodynamics in natural phenomena and technological processes
Authors: Mamas N. N. , Poltorak Ya. A. , Tretyakov V. E.
Published: November 2024

Hydrodynamics today plays an important role in understanding natural phenomena and technological processes. Mathematical description of fluid motion makes it possible to predict and analyze the behavior of liquids and gases under various conditions. Ideal liquids are convenient for mathematical calculations because they have viscosity. - Is an important aspect in analyzing the motion of fluids in nature and industry. Understanding the interaction of liquids and gases with solids is important not only for studying the properties of matter in depth, but also for practical applications in various branches of science and technology. Theoretical fluid dynamics is the foundation for understanding the laws of fluid and gas motion. Hydrodynamics is an integral part of modern engineering practice and research, ensuring the development of technologies in various fields and improving the quality of life of people around the world. When ensuring the efficient functioning of technical systems, optimizing production processes and increasing the overall productivity of enterprises, the introduction of hydrodynamic principles makes it possible to reduce energy consumption, improve equipment performance and increase the stability of production processes, which makes this science an integral part of industrial activity. Modern advances in fluid dynamics are expanding knowledge of the behavior of fluid media and gases, but also contribute to the development of innovative technologies and research methods Hydrodynamics plays a key role in scientific and technical research, influencing many aspects of everyday life and industrial development, as well as providing new knowledge and tools for modern technology and innovation.
The possibilities of using artificial neural networks in the task automated troubleshooting aircraft
Authors: Chub Vadim , Tsvetkova Olga
Published: November 2024

The widespread development and integration of information technologies leads to fundamental changes in almost all professional spheres of human activity. One of the most relevant directions in the development of this technology segment is the creation of intelligent tools that allow optimizing and rationalizing technological processes. The main purpose of the presented article is to perform an analysis regarding the possibility of using artificial neural networks as part of the task of automated troubleshooting of an aircraft. As a result of the work, the need to automate this task is actualized. The question is raised about the low efficiency of performing manual troubleshooting. The author confirms the need to develop completely new technologies to complete the search, which should be based on the use of intelligent technologies. In the framework of the work, the most appropriate and effective tools and methods are selected for the implementation of this module. Based on the results obtained, a universal algorithm is formed, it is also a methodology for developing a software module designed to automate the process of troubleshooting an aircraft. The key results were the obtaining of a scientific basis for the implementation of the proposed solution, as well as the systematization of the main possibilities and advantages of its use in practice. The materials of the work can be useful for modern researchers and engineers in the field of aviation, directing efforts to create universal intelligent systems for troubleshooting aircraft.
The future of robotic movement in virtual environment: Efficacy and profitability
Authors: Esmurzaeva Madina , Aygumov Timur , Tseeva Fatimat
Published: November 2024

One of the main goals of humanity is to move further with each generation and introduce new ways for comfort and development. At the moment, we have reached a level that was a fantasy a few centuries ago. New devices and technologies are introduced constantly, and most of them decay before reaching the market or the user. A new era of technological revolution is near, and therefore, we must be ready with the technology we have now. This article aims to illustrate that some technology can be used to prepare us for the future. By utilizing available technology to test and virtually advance emerging technologies, we can make their transition and establishment easier.
The use of AI in the food industry
Authors: Magomadov Sherip , Tokov Asker , Bakhareva Olga
Published: November 2024

One of the pending issues in the modern time is food security. Food safety is under a great threat with the unstable weather conditions, environmental disasters and overpopulation. Therefore, the main aim of the work is to illustrate that there are tools that can positively influence food industry. The so-called tool is artificial intelligence, which is well integrated in various industries. Food industry is no exception when it comes to artificial intelligence. Artificial intelligence is used in different areas in food industry to maximise the production rate, cut the overall time of the processes, reduce errors and waste and more. The work will briefly go through the basics of artificial intelligence. The work will examine the following areas: food inspection, classification and prediction of the parameters, quality control, food safety, navigation. At the end drawbacks of the technology will be covered.
Modeling the braking process for motorcycle with ABS
Authors: Mikhaltsevich Mikalai , Ziyaev Kamoliddin
Published: November 2024

The project introduces the braking system for motorcycle with ABS and simulation the braking process using the Tire Hardware-In-The- Loop Simulator (Tire HILS). The ABS system includes electronic and hydraulic control units and wheel velocity sensors. The original pre-extreme algorithm is used to ABS control. The mathematical description of the pre-extreme control method is presented. Mathematical model has been developed for this method of anti-lock braking system operation during curvilinear motorcycle driving. This model was developed considering the possibility of obtaining the necessary data for the operation of the ABS without developing a new sensors base.
Statistical evaluation of regenerative braking of trucks with energy efficient mechatronic transmission
Authors: Lobachev Ivan , Khlobystov Ilya , Potashnikov Maksim , Buzunov Nikolai , Kartashov Aleksander
Published: November 2024

The article assesses the capabilities of regenerative braking in terms of braking efficiency when studying the motion of a model of an energy-efficient electric vehicle with a mechatronic transmission using motion cycles recorded on real vehicles. Based on statistical data, a study of driving conditions was conducted, the required braking power and the required braking deceleration were calculated, and the obtained requirements were compared with the capabilities of the traction motors installed on the vehicle, taking into account the peak short-term characteristic. Based on the results of the work, a conclusion was made that the use of energy-efficient traction electric motors allows in 86% of cases to do without using the service braking system, providing the required level of deceleration according to the studied motion cycles, which fully corresponds to serial models of electric trucks.
Methodology for selecting an estimation of vehicle controllability and stability parameters
Authors: Proshin Dmitri , Molev Yuri , Belyaev Alexander , Makarov Vladimir
Published: November 2024

This paper presents the results of estimation of the controllability and stability of vehicles when driving on roads with a low coefficient of adhesion. The currently existing methods for determining these parameters are described, their main advantages and disadvantages are noted. Based on the analysis of statistical data on road accidents, a new parameter of controllability and stability has been proposed - the stability of the vehicle’s trajectory during braking when lateral forces act on it. Its permissible numerical values are determined and verification methods are proposed. The results obtained make it possible to improve road safety when operating a vehicle in difficult road conditions.
Analysis of the semileptonic Bc → D*sµ+µ- decay mode in the effective field theory approach
Authors: Yadav Ajay Kumar , Mohapatra Manas Kumar , Sahoo Suchismita
Published: November 2024

Discrepancies have been noted between experimental measurements and Standard Model predictions for various observables related to the B → (K, K∗, ϕ)ll processes. Recently, the Belle-II Collaboration observed a 2.8σ deviation from Standard Model predictions in the branching ratio of the B → Kνl ν¯l decay mode. In this context, we investigate the exclusive semileptonic Bc → D*sµ+µ- decay mode, mediated by b → s quark level transition, using Effective Field Theory formalism. We perform a global fit to the new parameters using existing experimental data on b → sµ+µ−. We then estimate the branching ratio and other observables such as forward-backward asymmetry, lepton polarisation asymmetry, and the lepton non-universality parameter of the Bc → D(*)sµ+µ- process. Although this process has not yet been detected experimentally, we offer predictions and discuss the observables for Bc → D*sµ+µ- in both the Standard Model and potential new physics scenarios.
Exploring Flavor Anomalies and Dark Matter in U(1)Le−Lµ model with a scalar Leptoquark
Authors: Mohapatra Manas Kumar , Singirala Shibaramkrishna , Panda Dhiren , Mohanta Rukmani
Published: November 2024

We explore U(1)Le −Lµ gauge extension of the Standard model with particle content enlarged by three neutral fermions, of which the lightest one contributes to dark matter content of the Universe. The scalar sector is enriched with a scalar leptoquark doublet to investigate flavor anomalies in B-meson sector, an additional inert scalar doublet to realize neutrino mass at one loop and a scalar singlet to spontaneously break the new U(1). We discuss dark matter relic density and direct detection cross section in scalar and gauge portals. New physics contribution for transition comes from penguin diagrams with Z′, leptquark and new fermions. We analyze the constraints on the model parameters from the established observables such as $$ P_{5}^\prime $$, Br(B → (K(∗), ϕ)µµ), and Br(Bs → µµ) processes. Utilizing the permissible parameter space consistent with both flavor and dark sectors, we discuss the impact on various observables such as branching ratio and Lepton polarisation asymmetry of the Λb → Λ∗ℓ+ℓ− decay channel.
Le traitement chirurgical des ulcères de cornée
Authors: Caillon Adrien , Douet Jean-Yves
Published: November 2024

L’ulcère cornéen est une des affections oculaires les plus fréquentes chez les carnivores domestiques. Le traitement est avant tout médical et adapté en fonction des caractéristiques de la perte de substance cornéenne. Le recours à la chirurgie est recommandé en cas d’ulcère cornéen profond (perte > 50 % de l’épaisseur cornéenne), de plaie cornéenne traumatique, d’ulcère à collagénases (lyse excessive du stroma cornéen avec risque de perforation) ou de nécessité de kératectomie (séquestre cornéen accompagnant un ulcère superficiel chronique chez le chat, etc.). L’objectif de la chirurgie est alors de préserver l’intégrité du globe tout en maximisant la transparence cornéenne après cicatrisation. Les principales options chirurgicales incluent la greffe de conjonctive, de cornée, de biomatériaux, la transposition cornéo-conjonctivale (TCC), l’utilisation de colle de cyanoacrylate ou encore le Cross-linking cornéen. Le choix du traitement sera basé sur une évaluation de la balance bénéfice/ risque de chaque technique faisant intervenir la sécurité de la technique chirurgicale (propriétés antimicrobiennes et anticollagénases des greffes de conjonctive par l’apport vasculaire) et l’opacité en résultant (TCC, greffes de cornée et de biomatériaux restaurant en général une meilleure transparence cornéenne).
La consultation d’acquisition d’un reptile
Authors: Palmero Audrey , Caminade Tristan
Published: November 2024

Cet article présente les aspects clés d’une consultation d’acquisition d’un reptile. Ce processus est crucial pour établir la confiance entre vétérinaires et clients et pour prévenir les maladies pouvant affecter significativement la qualité et la durée de vie des reptiles. Une discussion détaillée sur l’espace de vie, la température, l’humidité, l’éclairage et l’alimentation du patient reptile est essentielle avant tout examen clinique. La consultation aborde ainsi spécifiquement les besoins environnementaux et nutritionnels, identifie les erreurs courantes de zootechnie, tout en soulignant l’importance des mesures d’hygiène, de la quarantaine et des examens préventifs de dépistage.
Traitement médical des ulcères cornéens du chien et du chat
Authors: Meunier Valérie
Published: November 2024

Les ulcères de cornée sont des affections fréquentes chez les carnivores domestiques. Quel que soit leur degré de gravité, un traitement médical doit être instauré en première intention, associé ou non à un traitement chirurgical. Soulager la douleur par un traitement topique ou par voie générale est indispensable pour que l’animal accepte les autres traitements associés. Le port d’un carcan est évalué selon chaque cas. Un antibiotique topique large spectre doit être prescrit systématiquement et son efficacité évaluée au bout de quelques jours. Bien connaître le spectre microbien de chaque molécule permet de réorienter le traitement en fonction de l’évolution. Chez le chat, en cas d’ulcère herpétique, des traitements antiviraux seront associés. Les inhibiteurs enzymatiques sont nécessaires en cas de lyse bactérienne dans les ulcères profonds. Quant aux adjuvants de cicatrisation, ils peuvent se révéler efficaces et participer à la reconstruction cornéenne.
Communication interventriculaire chez une chèvre : cas clinique
Authors: Bouaicha Faten , Terrade Gauthier , Chabane Amel , Denis Marine , Reyes-Gomez Édouard , Ravary Bérangère
Published: November 2024

Une chevrette de 12 mois est présentée pour distension abdominale évoluant depuis 2 semaines et aboutissant à un décubitus sternal. L’examen physique et les examens complémentaires orientent le diagnostic vers une malformation cardiaque. L’examen nécropsique confirme la présence de 2 communications interventriculaires. Ce cas illustre qu’il faut suspecter une malformation cardiaque chez les caprins en cas de distension abdominale avec signe du flot, même si l’animal est déjà relativement âgé.
Counting the Unit Solutions of Certain Quartic Diagonal Congruence Modulo n
Authors: ZHAO Junyong , HU Shuangnian , YIN Qiuyu
Published: November 2024

Given a positive integer [see formula in PDF] and the residue class ring [see formula in PDF], we set [see formula in PDF] to be the group of units in[see formula in PDF], i.e., [see formula in PDF]. Let [see formula in PDF] be the number of solutions of[see formula in PDF] with [see formula in PDF]. In this note, we determine an explicit expression of [see formula in PDF]. This extends the results of Sun and Yang in 2014.
E-Total Coloring of Complete Bipartite Graphs K5,n (5≤n≤7 113) Which Are Vertex-Distinguished by Multiple Sets
Authors: GUO Yaqin , CHEN Xiang'en
Published: November 2024

In this study, using the method of contradiction and the pre-assignment of chromatic sets, we discuss the E-total coloring of complete bipartite graphs K5,n (5≤n≤7 113) which are vertex-distinguished by multiple sets. The vertex-distinguishing E-total chromatic numbers of this kind of graph are determined.
Schwere Komplikationen bei Lebendimpfungen
Authors: Gothe Florian
Published: November 2024

Lebendimpfstoffe erzeugen eine starke, lang-anhaltende Immunität und haben Millionen Menschenleben weltweit gerettet. Sehr selten jedoch können sich angeborene Störungen des Immunsystems nach einer Lebendimpfung manifestieren. Im vorliegenden Beitrag sollen anhand monogenetischer Immundefekte entscheidende Mechanismen der antiviralen Immunität diskutiert werden. Das Verständnis der jeweiligen pathophysiologischen Grundlagen erlaubt Rückschlüsse beispielsweise auf die Impfstoffentwicklung.
CT Coronary Angiogram in Diagnosing IgG4 of Coronary Arteries Presenting as Acute Coronary Syndrome: A Case Report with Literature Review
Authors: Choudhury Apratim Roy , Valakkada Jineesh , Ayappan Anoop , Sharma Smily
Published: November 2024

Immunoglobulin G4-related disease (IgG4 RD), first described in 2001, as a case of autoimmune pancreatitis, is a multisystemic condition, involving the salivary glands, bile ducts, pancreas, retroperitoneal organs, and mesentery and is associated with raised level of serum IgG4. Reports of coronary involvement by IgG4 RD are scarce and we could find only 16 case reports in the literature. Here, we present a case of a 61-year-old lady, with no known comorbidities, who presented with rapid progression of coronary artery stenosis. Initially, she presented with mild stenosis of left anterior descending which rapidly progressed to significant triple vessel disease in 3 months. Serological workup for antibodies was negative, except for raised serum IgG4 antibodies. She was managed effectively with steroids.
Molecular-dynamics calculation of thermodynamic properties and structure system of liquid argon nuclei
Authors: Protsenko S. P. , Skripov V. P.
Published: November 2024

A microheterogeneous system of argon is represented by a mathematical model consisting of droplets in a vapor, and the model is subjected to molecular-dynamic analysis. Phase equilibrium in the system is established; thermodynamic parameters are calculated; and a study is made of the form of the phase interface and the molecular structure of the model system.
Manifestations of 2 1/2-order transitions and Kohn singularities in the pressure dependence of the superconducting transition temperature
Authors: Makarov V. I.
Published: November 2024

A theory is suggested for the pressure behavior of Tc in superconductors which accounts for changes due to pressure not only in the energy spectrum of conduction electrons but also in the phonon spectrum and in the electron-phonon interaction function. It is shown that in a superconductor subjected to pressure ∂Tc/∂P may have two types of singularities: one type due to the 2 1/2-order transition and another due to Kohn singularity. The dependence of ∂Tc/∂P on the impurity concentration is a reliable indicator which can be used to distinguish between these two types of singularities experimentally.
Two-photon light absorption in antiferromagnetic crystals with spin-forbidden transitions
Authors: Bron R. Ya. , Dokashenko V. P. , Matyushkin É. V.
Published: November 2024

It is shown that the method of two-photon spectroscopy of crystals with spin-forbidden transitions enables us to measure the contribution to the intensity of light absorption from mechanisms which remove spin exclusion. The exchange interaction is proposed as the basic mechanism responsible for the removal of spin exclusion in antiferromagnetic compounds of manganese.
Sound absorption in metals with several groups of carriers
Authors: Tarasov Yu. V. , Usatenko O. V. , Yampol'skii V. A.
Published: November 2024

The deformational absorption coefficient for sound in a metal placed in a strong magnetic field H (kR ≪ 1, k⊥H, k is the sound wave vector and R is the radius of the electron orbits) is calculated on the assumption that the carrier Fermi surface consists of two isolated groups. It is shown that in different frequency intervals the absorption is governed either by the constant or by the varying part of the deformation potential.
Fluctuational character of phase transition development in liquid helium
Authors: Smirnov A. P.
Published: November 2024

The temperature dependences of the relative normal fluid density ρn/ρ of liquid helium at low temperatures and of the superfluid to normal-fluid density ratio ρs/ρn. at higher temperatures have been analyzed following the results of Ref. 2, similarly to the analysis of the superconducting transition in mercury threads. It is shown that the temperature range 0.8−4°K can be treated as a fluctuation­ smeared phase transition in liquid helium (to the superfluid stale) proceeding, similarly to superconductors, in three stages with characteristic temperatures Tc1 = 1·4°K and Tc0 = T1 = 2.172°K separating regions with exponential temperature dependences of ρn/ρ and ps/ρn.
Current-voltage characteristics of low-capacitance Josephson junctions
Authors: Zorin A. B. , Likharev K. K.
Published: November 2024

The current–voltage characteristics of a low-capacitance Josephson junction are calculated on the basis of the well developed theory of the Josephson effect in tunnel junctions. The possibility of applying this theory to a description of Josephson junctions with indirect conductivity is evaluated.
Magnetic susceptibility of lithium-magnesium alloys
Authors: Svechkarev I. V. , Sokoland O. M. , Kuz’micheva L. B.
Published: November 2024

The magnetic susceptibility of body-centered cubic lattice (bcc) solid solutions of lithium with magnesium is investigated. A model analysis is carried out of the susceptibility and its temperature dependence. Data are obtained about the behavior of the electron spectra parameters, the exchange enhancement properties of spin paramagnetism and the scattering of electrons in the lithium–magnesium system.
High-frequency AFMR branch in quasi-one-dimensional CsMnCl3·H2O and associated two-magon excitations
Authors: Anders A. G. , Zvyagin A. I. , Petutin A. I.
Published: November 2024

A study was made of microwave power absorption in a quasi-one-dimensional antiferromagnetic, CsMnCl3·H2O, at frequencies of 25–130 GHz and T = 1.46°K. Uniform antiferromagnetic resonance associated with excitation of the upper branches was investigated. The absorption spectrum exhibited features due to the low-dimensional magnetic structure of one crystal, viz., two-magnon subthreshold absorption involving magnons from the upper and lower branches of the spin-wave spectrum.
Thermodynamic properties of AuGa2 under pressure
Authors: Palistrant M. E. , Trifan A. T.
Published: November 2024

The pressure dependence of the critical temperture Tc, of the heat-capacity jump at T = Tc, of the order parameter Δ, and of the thermodynamic critical field Hc at T = 0 is analyzed here according to the model of topological changes in the Fermi surface (formation of a flat segment).
Thermal processes in superconductors carrying a load current
Authors: Shablo A. A.
Published: November 2024

Results are presented of an experimental study concerning the effect of thermal processes on the emergence of the resistive state while a current destroys the superconductivity. In film specimens having constrictions (bridges) and carrying a load current larger than critical the transition from natural convection to bubble boiling lowers the temperature of the specimen and produces a decreasing range along the current–voltage characteristic. The negative-differential-resistance range disappears either during measurements in superfluid helium or in the absence of a direct contact with helium.
Low-temperature heat capacity and dynamic properties of DNA as a quasi-one-dimensional system
Authors: Verkin B. I. , Sukharevski V. Ya. , Telezhenko Yu. V. , Alapina A. V. , Vorobyova N. Yu.
Published: November 2024

The heat capacity of DNA films was measured in the temperature range 4.2−400°K. The linear dependence it is observed to have in the range 4.2−180°K makes it possible to treat the dynamic properties of DNA within the framework of the theory of low-dimensional crystals. Experimental data are used to determine the “one-dimensional” Debye temperature θ1 = 560°K(ω0 = 7.6·1013 Hz) and the propagation velocity of elastic oscillations, u = 124 m/sec. A model is suggested for a qualitative analysis of the results.
Dislocation and domains in an antiferromagnet
Authors: Kovalev A. S. , Kosevich A. M.
Published: November 2024

It is shown that in an antiferromagnet with anisotropy of the “easy plane” type a dislocation perpendicular to the plane can generate magnetic stacking faults. If the magnetic anisotropy in the plane is neglected, then a disclination of the magnetic ordering is associated with the dislocation. With fourth-order anisotropy, two-90-degree domain walls terminate at the dislocation.
Electromagnetic properties of “dirty” superconductors in strong high-frequency fields
Authors: Genkin V. M.
Published: November 2024

The electromagnetic properties of “dirty” superconductors with nonmagnetic impurities are investigated theoretically in strong high-frequency fields. It is shown that the dissipative part of the conductivity σ1,(ω) in a strong field of frequency ω0 has a singularity of the form 1/ω for ω ≪ ω0< 2 Δ and is negative at zero temperature. The sign of σ1(ω) becomes positive with an increase in temperature. Both σ1(ω) at ω0 ≪ ω < 2 Δ and σ2(ω) at ω ≪ ω0)≪ 2 Δ, (T =0) are calculated.
Spin-phonon interaction in semi-infinite ferromagnet
Authors: Tarasenko V. V. , Kharitonov V. D.
Published: November 2024

The processes of interactions between surface magnons and phonons in a semi-infinite ferromagnet are investigated. An analysis is made of the processes of surface spin-wave scattering and annihilation involving phonon emission (or absorption). The attenuation factors for surface spin-wave attenuation as a result of spin-lattice interaction are found for temperature μM0≪T≪θC, θD and the mean lifetimes of surface magnons are determined. The mechanisms responsible for relaxation of surface spin waves in an ideal semi-infinite ferromagnet are discussed.
Scattering of impuritons at phonons in solid helium
Authors: Mikheev V. A. , Esel'son B. N. , Grigor'ev V. N. , Mikhin N. P.
Published: November 2024

NMR has been used to measure the difffusion coefficient for weak solid solutions of 3He in 4He having concentrations x of 3He at or below 0.1%, the temperature range being 0.4−1.3 °K and the molar volume 21.0 cm3/mole. The weakest solution, which contained about 6·10−3% 3He, showed a substantial increase in D on reducing the temperature from 1.3 to 0.7°K. The temperature-dependent component of D follows the law D ∝ T−9, which agrees with the predictions of the theory {A. F. Andreev and I. M. Lifshits, Zh. Eksp. Teor. Fiz. 56, 2057 (1969) [Sov. Phys. JETP 29, 1107 (1969)} for phonon-collision limited impuriton diffusion. Therefore, the previously observed {Grigor'ev et al, Pis'ma Zh. Eksp. Teor. Fiz. 18, 289 (1973) [JETP Lett. 18, 169 (1973)} quantum diffusion mechanism, which is related to impuriton-impuriton interaction, is thus accompanied by scattering of impuritons by phonons in solid helium. Comparison with the theory {V. A. Slusareva and M. A. Strzhemechnyi, in: Physics of Low Temperature [in Russian] issue 19, FTINT Ukr SSR, Kharkov (1972), p. 85} gives the width of the impuriton energy band as about 10−4°K.
On the theory of anisotropic ferromagnets
Authors: Gaididei Yu. B. , Loktev V. M.
Published: November 2024

The spectrum of a ferromagnet with single-ion anisotropy is investigated. Using a special representation of the spin operators, the spin-wave spectrum is calculated taking exact account of anisotropy. It is shown that one of the FMR frequencies vanishes long before the magnetic phase transition is reached. The behavior of the system is investigated in the neighborhood of the point where the frequency vanishes, and an expression is obtained for TC of crystals with an arbitrary anisotropy constant.
Slip localization during discontinuous strain of niobium single crystals at 4.2 °K
Authors: Baraz A. R. , Molotilov B. V.
Published: November 2024

High-purity niobium single crystals were studied under deformation in a liquid-helium environment. A method developed by the authors was used to show that locally the shear strain could reach several hundred per cent within catastrophic shear bands with linear dimensions of roughly 5–12 μm. On the basis of the high degree of plastic strain localization and the high level of maximum local heating in the adiabatic approximation (160−180°K) it is suggested that local heating plays a leading role in the mechanism of discontinuous shear.
The height of the self-trapping barrier
Authors: Rashba É. I.
Published: November 2024

In the case of a nonpolarization electron-phonon interaction, the transition to the self-trapped state involves overcoming a potential barrier. In the case of a strong electron-phonon interaction, the barrier lies in the macroscopic region, although the scale of the self-trapped states always is of the order of the lattice constant. A formula is presented for the height of the self-trapping barrier.
On the possibility of an experimental determination of the spatial distribution of the order parameter in helium by the method of the inverse problem in a spectral formulation
Authors: Nemirovskii S. K.
Published: November 2024

The possibility is discussed of an experimental determination of the dependence of the order parameter in He II in a gravitational field on the coordinate in a region where the correlation effects are strong. It is proposed to use an experiment on the observation of the reflection of second sound from the inhomogeneity in the velocity of second sound connected with the inhomogeneity of the order parameter. The boundary problem for the study of second sound is formulated. It is shown how the experimental data are connected with the data of the inverse problem of scattering theory. The estimates presented show the possibilities of the realization of the proposed method.
Linde's law in alloys of normal metals
Authors: Aleksandrov B. N. , Dukin V. V.
Published: November 2024

It has been established from experimental data on the effect of various impurities on residual resistivity ρ0 of 14 metallic hosts (Li, Cu, Ag, Au, Mg, Zn, Cd, Hg, Al, Ga, In, Ti, Sn, Pb) that, for elements belonging to one period, the law Δρ/c = αΔZ2+bΔZ + d = α(ΔZ—α)2+β is obeyed, where Δρ/c is the experimentally determined change in resistivity of the host metal upon solution of 1 at. % of an impurity, and ΔZ is the difference between the valences of host and impurity. Analysis of 40 parabolas showed that the above relationship is satisfied for impurities from all periods, except that of the host metal itself. In the latter case one finds the relationship Δρ/c = α AZ2 Thus, in no case is the well known Linde law (Δρ/c= αΔZ2 + d) observed, except in the case of period VI impurities in lead. It was found that the most frequent values of the coefficient α are 0.4±0.1 and 0.8±0.l, while for several host metals there is a tendency to increase in α with increase in the host valence. It is proposed that the most significant cause of the observed shift in the parabolas α, aside from distortion of the host lattice by the impurity upon solution, is structural differenes between the host and impurity ions. The nature of the dependence of Δρ/c on ΔZ is also considered for transition metals alloyed with normal metal impurities and the contrary case. Using empirical parabolic dependences of Δρ/c on ΔZ, values of Δρ/c are predicted for 55 impurity-host pairs for which experimental data are lacking.
Quantum size effect in bismuth-antimony alloy films
Authors: Bukhshtab E. I. , Nikitin Yu. V. , Komnik Yu. F.
Published: November 2024

The electrical resistivity ρ of single-crystal bismuth-antimony alloy films was measured in specimens of varying thickness L and fixed Sb concentration c and in specimens of varying composition and fixed thickness. At 4.2° K the value of ρ oscillates with variation of both the specimen thickness and composition. Both kinds of oscillatory dependences are due to the size quantization of the charge carrier spectrum of thin films. The ρ(c) oscillations in constant thickness specimens are associated with the change of the maximum momentum caused by changes in the bismuth-antimony alloy composition. From the results obtained, a plot of the composition dependence of the maximum momentum along the C3 axis can be derived.
Shock synthesis of superconducting Ta3Si
Authors: Pan V. M. , Popov A. G. , Alekseevskii V. P. , Kulik O. G. , Yarosh V. V.
Published: November 2024

As a result of the explosive compression of tetragonal tantalum silicide Ta3Si, a superconducting modification is obtained with Tc ≤ 8.6° K and, apparently, with the A15 structure.
Thermodynamic perturbation theory and quantum effects in liquid hydrogen. I. Equilibrium bulk properties of liquid para-hydrogen
Authors: Marinin V. S. , Pashkov V. V.
Published: November 2024

A modified version of thermodynamic perturbation theory is used to calculate equilibrium properties of liquid hydrogen (the compressibility factor, the heat capacity, and the sound velocity). The considerable contribution due to quantum effects is taken into account by using the quantum hard-sphere model as an unperturbed system. The properties of this system are calculated in the formalism of “modified” Ursell functions. The calculated thermodynamic quantities are in good agreement with experimental data in a wide range of states. Possibilities for further development of the suggested method are discussed.
Vortex pinning on grain boundaries in Pb-ln alloys
Authors: Vinnikov L. Ya. , Zharikov O. V. , Kopetskii Ch. V. , Moskvin S. I.
Published: November 2024

The critical current density J has been studied experimentally as a function of the external magnetic field H, the grain size d, the relative anisotropy α = ΔHc2/Hc2, and the Ginzburg-Landau parameter κ in a series of polycrystalline lead-indium alloys containing 1.4, 2.1, 5, 11.8, and 18 at.% In. The dependence of Jc on 1/d has been found to increase as α increases and κ decreases. The results warrant the conclusion that the anisotropy of the superconducting properties is the controlling factor for vortex pinning on grain boundaries. A comparison is made with the calculations of Dew-Hughes and Whitcomb2 [J. Phil. Mag. 26, 73 (1972)] and Shmidt {Zh. Eksp. Teor. Fiz. 68, 186 (1975) [Sov. Phys. JETP 41, 90(1975)}.
Navigating large scale ocean science in a Pacific small island developing state
Authors: Claassens L. , Hernández C. M. , Biondi P. , Jaskiel J. , Muller Karanassos C. , Mesengei M. , Nestor V. , Otto E. I. , Renguul H. , Rotjan R. D. , Sartori G. , Tatebe L.
Published: November 2024

Context In pursuit of protecting 30% of the ocean by 2030, large scale marine protected areas (LSMPAs) are rapidly increasing, especially in small island developing states (SIDS). Many SIDS have limited offshore research expertise or capacity to evaluate the efficacy of LSMPAs. The offshore Palau National Marine Sanctuary (PNMS) necessitated the Republic of Palau to develop its offshore research ability aimed at supporting science-based management. Owing to Palau’s important tuna fishery, investigating tuna reproductive biology in the PNMS was prioritized as a first step in evaluating the protective significance of the PNMS for tuna. Aims The aim of this study was to develop a useful and practical platform to conduct large scale ocean research within the context of SIDS. Methods A platform to conduct offshore research was developed. Reproductive histology and the presence and abundance of larvae were used to investigate tuna reproductive biology in the PNMS. Key results Most tunas sampled were mature, with 3 of the 59 sampled fish actively spawning. Twenty-two tuna larvae were collected across five offshore sites, and modeling results suggest larvae originated from these sites. Conclusions Findings suggest tuna spawn, to some extent, within the PNMS, and the PNMS provides local protection to tuna populations during this time. A research platform with five steps for developing, undertaking and understanding offshore research in SIDS was developed. Challenges and tips experienced are also detailed. Implications This platform can support the ever-increasing demand for offshore research in small island, large ocean states with limited resources and expertise.
Identification of a dengue 2 virus envelope protein receptor in
Aedes aegypti
critical for viral midgut infection
Authors: Kantor Asher M. , Talyuli Octavio A. C. , Reid William R. , Alvarenga Patricia Hessab , Booker Jasmine , Lin Jingyi , Franz Alexander W. E. , Barillas-Mury Carolina
Published: November 2024

The establishment of a productive dengue virus (DENV) infection in the midgut epithelial cells of
Aedes aegypti
is critical for the viral transmission cycle. The hypothesis that DENV virions interact directly with specific mosquito midgut proteins was explored. We found that DENV serotype 2 (DENV2) pretreated with trypsin interacted with a single 31 kDa protein, identified as AAEL011180 by protein mass spectrometry. This putative receptor is a highly conserved protein and has orthologs in culicine and anopheline mosquitoes. We confirmed that impairing the expression of AAEL011180 in the midgut of
Ae. aegypti
females abolished the interaction with DENV2, and the virus also bound to immobilized recombinant purified receptor. Furthermore, recombinant DENV2 surface E glycoprotein bound to recombinant AAEL011180 with high affinity (38.2 nM) in binding kinetic analysis using surface plasmon resonance. The gene for this DENV2 E protein receptor (EPrRec) was disrupted, but since the gene is essential in
Ae. aegypti,
only heterozygote knockout (ΔEPrRec
+/−
) females could be recovered. Further reducing EPrRec mRNA expression in the midgut of ΔEPrRec
+/−
females by systemic dsRNA injection significantly reduced the prevalence of DENV2 midgut infection. EPrRec also interacts with heat shock protein 70 cognate 3 (Hsc70-3), and silencing Hsc70-3 expression in ΔEPrRec females also reduced the prevalence of DENV2 midgut infection.
Recent developments in superjunction power devices
Authors: Ma Chao , Chen Weizhong , Liu Teng , Zhang Wentong , Zhang Bo
Published: November 2024

Superjunction (SJ) is one of the most innovative concepts in the field of power semiconductor devices and is often referred to as a "milestone" in power MOS. Its balanced charge field modulation mechanism breaks through the strong dependency between the doping concentration in the drift region and the breakdown voltage V
B in conventional devices. This results in a reduction of the trade-off relationship between specific on-resistance R
on,sp and V
B from the conventional R
on,sp∝V
B
2.5 to R
on,sp∝W∙V
B
1.32, and even to R
on,sp∝W·V
B
1.03. As the exponential term coefficient decreases, R
on,sp decreases with the cell width W, exhibiting a development pattern reminiscent of "Moore’s Law". This paper provides an overview of the latest research developments in SJ power semiconductor devices. Firstly, it introduces the minimum specific on-resistance R
on,min theory of SJ devices, along with its combination with special effects like 3-D depletion and tunneling, discussing the development of R
on,min theory in the wide bandgap SJ field. Subsequently, it discusses the latest advancements in silicon-based and wide bandgap SJ power devices. Finally, it introduces the homogenization field (HOF) and high-K voltage-sustaining layers derived from the concept of SJ charge balance. SJ has made significant progress in device performance, reliability, and integration, and in the future, it will continue to evolve through deeper integration with different materials, processes, and packaging technologies, enhancing the overall performance of semiconductor power devices.
Nanocomposite superstructure of zinc oxide mesocrystal/reduced graphene oxide with effective photoconductivity
Authors: Ahmad Ahmad A. , Al-Bataineh Qais M. , Migdadi Ahmad B.
Published: November 2024

Metal oxide mesocrystals are the alignment of metal oxide nanoparticles building blocks into the ordered superstructure, which have potentially tunable optical, electronic, and electrical properties suitable for practical applications. Herein, we report an effective method for synthesizing mesocrystal zinc oxide nanorods (ZnONRs). The crystal, surface, and internal structures of the zinc oxide mesocrystals were fully characterized. Mesocrystal zinc oxide nanorods/reduced graphene oxide (ZnONRs/rGO) nanocomposite superstructure were synthesized also using the hydrothermal method. The crystal, surface, chemical, and internal structures of the ZnONRs/rGO nanocomposite superstructure were also fully characterized. The optical absorption coefficient, bandgap energy, band structure, and electrical conductivity of the ZnONRs/rGO nanocomposite superstructure were investigated to understand its optoelectronic and electrical properties. Finally, the photoconductivity of the ZnONRs/rGO nanocomposite superstructure was explored to find the possibilities of using this nanocomposite superstructure for ultraviolet (UV) photodetection applications. Finally, we concluded that the ZnONRs/rGO nanocomposite superstructure has high UV sensitivity and is suitable for UV detector applications.
A new and highly precise forecasting method based on multiple input Convolutional Neural Networks and Generative Adversarial Networks for training data set augmentation
Authors: Boicea Adrian-Valentin , Vulpe-Grigoraşi Adrian
Published: November 2024

Forecasting is essential when it comes to power system operation. It is always equivalent with higher revenues and, implicitly, lower maintenance costs. That is why, it is the purpose of this work to introduce a new and highly precise wind power forecasting neural model based on a multiple input (multi-channel) Convolutional Neural Network (CNN) and a Generative Adversarial Network (GAN) for training data augmentation. The training of the CNN is conducted simultaneously with historical data related to both power generation and wind speeds.
Tri-band planar antenna for a small robotic vehicle
Authors: Richterova M , Virgala J , Popela M , Kuzel P
Published: November 2024

This paper describes the design, analysis of properties and fabrication of a tri-band antenna for a small robotic vehicle. The E-shaped tri-band antenna was chosen for its simplicity, practicality and universality. The design of the tri-band antenna and the simulation of its properties were implemented in the Matlab programming environment using the Antenna Toolbox extension. The designed tri-band antenna was fabricated, its properties were measured and the measured results are compared with the simulations for subsequent analysis.
Multimodal evaluations of electromagnetic hazards while using MRI systems
Authors: Karpowicz Jolanta
Published: November 2024

At the heart of evaluating electromagnetic hazards near magnetic resonance imaging (MRI) systems used in medical diagnostics is to reveal the range of space surrounding the system that is affected by static magnetic field (SMF) to an extent potentially causing: (a) movement-related disturbances in human balance, which may lead to direct safety hazards for affected workers or patients; (b) a projectile effect in heavy ferromagnetic objects, which may create lethal hazards for workers and patients, as well as serious damage to the MRI scanner; (c) a projectile effect in small ferromagnetic objects, which may cause non-lethal hazards for workers or patients, for example by cutting the skin of a person hit by an object, though this is usually not dangerous to the MRI equipment. Additionally, thermal and electrodynamic effects in humans and equipment affected by time-varying MRI emissions (gradient and radiofrequency fields) need evaluation and prevention. The characteristics of static and time-varying electromagnetic fields near MRI systems and a multimodal evaluation of related hazards are discussed based on results of long-term environmental studies – using an exposure-oriented evaluation applying exposure limits or action levels, as well as a space-oriented evaluation applying the concept of Functional Intervention Levels (FIL). The newly tested applicability of autonomous EMF data loggers when evaluating these electromagnetic hazards near MRI systems is also considered.
Electromagnetic exposure of population in three cities of Romania at four years difference, based on data recorded by the fixed national radiofrequency monitoring network
Authors: Deaconescu D B , Petrita T , Miclaus S
Published: November 2024

The blooming of wireless technologies and the deployment of the fifth generation (5G) of mobile communications have been accompanied by a significant increase in the risk perception related to human exposure to radio-frequency electromagnetic field (RF-EMF). Therefore, EMF monitoring has become necessary in areas with increased densification of the EMF sources. Present work made use of the raw data kindly provided by the National Authority for Management and Regulation in Communications (ANCOM) in Romania from the fixed EMF sensor network nationally deployed. We aimed to analyze the case of electric field level evolution after four years, in three cities. In each city a single monitoring station was chosen in the analysis. Database in the wide- and narrow-bandwidths covering the range (100 kHz – 7 GHz) was processed for whole years 2019 and 2023. Comparisons between locations and years were enabled by means of: a) descriptive statistics; b) time series analysis with Poincare plots for time-variability characterization; c) recurrence quantification analysis to emphasize the nonlinear dynamics of the exposure levels, respectively the recurring exposure levels dynamics. Similarities and dissimilarities were observed and discussed.
Chemical biosensor for detecting immunity against viral diseases (SARS-COV2)
Authors: Vlad-Alexandru Anitei , Munteanu Mihai
Published: November 2024

Due to the need of developing means of rapid testing for SARS COV 2 virus infection, a series of methods for fast investigation of individuals have been created. In this regard, this article proposes a colorimetric testing method for the infection, using a chemically modified paper support and an RGB analysis method to identify positive tests.
Impact of a MATLAB-controlled application on the autonomy of ischemic stroke patients in the hospital
Authors: Ivascu D. A. , Munteanu M.
Published: November 2024

This study explores the possibility of using a Matlab-controlled electromyographic system, based on a microcontroller, in monitoring and assisting patients with contralateral hemiplegia following an ischemic stroke, paralyzed on one side of the body and bedridden. The main aim is, by generating electrical signals based on the level of flexion of the patient’s healthy arm or clenching of the patient’s healthy fist, the system can control various devices and alert medical staff. The technology provides support and independence to patients in performing some of their daily activities.
Dynamic Forecasting of COVID-19 Spread Using ARMAX Models
Authors: Stancioi Cristina-Maria , Muresan Vlad , Abrudean Mihail , Stelian Munteanu Mihai , Sita Valentin
Published: November 2024

The COVID-19 pandemic, unprecedented in the last 100 years, struck with the massive impact it had on humanity in multiple ways, but from the medical perspective the unpredictability of the course of the disease and the wide spectrum of clinical manifestations, with extreme serious and lethal accents for a percentage of patients, was a massive reason for concern. Therefore, researchers are still trying to decipher the body’s immune response and the duration of protection against a new reinfection. Immunological memory is the basis of durable protective immunity after infections or vaccinations. Its duration after infection with coronavirus 2 (SARS-CoV-2) is still under study, but more and more data are coming to complete this puzzle. Accurately foreseeing the virus’s progress is critical for allocating medical resources, managing industry operations, and maintaining economic growth. To this goal, dependable and appropriate forecasting techniques based on strong mathematical models are required. This paper investigates the use of ARMAX (Autoregressive Moving Average with Exogenous Inputs) models to forecast epidemiological trends in COVID-19 outbreaks, with an emphasis on Romania.