bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal management strategies for gallium oxide vertical trench-fin MOSFETs
Authors: Montgomery Robert H. , Zhang Yuewei , Yuan Chao , Kim Samuel , Shi Jingjing , Itoh Takeki , Mauze Akhil , Kumar Satish , Speck James , Graham Samuel
Published: February 2021

Trench-fin MOSFETs, with their near-surface heat generation and the higher-surface area afforded by their geometry for thermal management, represent a promising solution to the thermal problems frequently encountered in lateral β-Ga2O3 devices. Here, we investigate potential thermal-management strategies for a vertical β-Ga2O3 trench-fin MOSFET through parametric analysis, offering recommendations on how best to design a device for maximal current density and excellent thermal performance. Primarily, by using a thermally conductive dielectric over the MOSFET structure, significant improvements to device power density may be achieved, aided by thermal spreading. Additionally, we find that by bonding thermal spreaders to its topside can yield significant improvements in thermal performance.
Energy band engineering toward hardened electronics in ionizing radiation environments via quantum gettering
Authors: Goodman Kevin , Morgan Timothy , Ghosh Pijush Kanti , Cooper Robert , McHenry Samuel , Titus Jeff , Kuchuk Andrian V. , Halstead Matthew , Ware Morgan
Published: February 2021

Ionizing radiation has the potential to cause operational disruptions and destroy microelectronic devices. This paper introduces and demonstrates a method of hardening microelectronic devices for sustained use in applications where exposure to ionizing radiation exists. By incorporating quantum structures below active regions of devices, gettering of charges created by ionizing radiation becomes possible. The gettering of electrons and holes forces recombination of carriers, thus eliminating photocurrent surges and trap filling which would otherwise disrupt device operation. Experimental results discussed here show a reduction in photocurrent of over two orders of magnitude when utilizing energy band engineering to create quantum structures for charge gettering. In this work, a nitride-based high electron mobility two-dimensional electron gas demonstrates the method. However, the theory utilized pertains not only to nitride-based devices, but transfers to other materials as well.
Developing microscopy based microfluidic SLS assay for on-chip hemoglobin estimation
Authors: Arcot Lokanathan , Kandaswamy Srinivasan , Modali Anil , Gorthi Sai Siva , Rai Dastidar Tathagato
Published: February 2021

Point-of-care (POC) biochemical assay is a highly important biochemical assay to estimate hemoglobin in the blood. High reagent volumes and complex-expensive optical setup requirements pose serious challenges when it comes to adopting conventional biochemical assays such as the Sodium Lauryl Sulfate (SLS) method into a POC device. Here, we report a modified SLS assay on a microfluidic platform, wherein the quantification is achieved using a simple microscopy-based imaging setup. Assay parameters, including SLS reagent-to-blood volume ratio, total reaction volume, the concentration of sodium dodecyl sulfate, and microfluidic chamber design, were optimized in order to achieve quantitation capability across a clinical range of hemoglobin using a path length suitable for the microfluidic platform. Besides quantitative correlation with a clinically accepted-validated standard method, the spectral absorption characteristics of the hemoglobin–SLS reagent mixture in the newly developed assay were compared with those of conventional SLS assays. The finalized chip design, including the reagent, cost 0.136 USD. The microfluidic chip in combination with an automated microscope was able to achieve a Pearson correlation of 0.99 in a validation study comparing the newly developed method and a commercially available hematology analyzer, with a turnaround time of 10 min, including incubation time. The clinical performance was ascertained, and the method achieved a sensitivity of 92.3% and a specificity of 53.8%. Overall, an automated microscopy-based biochemical assay was developed to estimate hemoglobin in whole-blood, using microfluidics technology, wherein the detector was a conventional camera associated with microscopy.
The impact of flow displacement patterns on hydraulic tortuosity for unsaturated flow
Authors: Guo Xiaokang , Wang Xiaodong
Published: February 2021

Hydraulic tortuosity is one of the key parameters used to characterize the fluid transport properties of porous media. One of the existing debates on hydraulic tortuosity is whether it is an intrinsic property or a correction factor to match the experimental data with a particular model. In this study, a series of immiscible displacement simulations with different capillary numbers and contact angles were established by using the phase field method based on three-dimensional micro-computed tomography images of porous media. Then, the vector-based tortuosity method based on the flow velocity field is used to predict the dynamic evolution of hydraulic tortuosity of unsaturated porous media. Interestingly, the transient hydraulic tortuosity at different flow displacement patterns shows different dynamic evolutions where the quasi-steady-state hydraulic tortuosity is related to both the fluid saturation and the characteristics of the trapped voids in the porous media. These phenomena can be explained by the complex and interesting pore-scale displacement events, including viscous self-correcting smoothing, noncooperative Haines jumps, capillary self-correcting smoothing, and corner flow.
Depletion of lubricant impregnated in a cavity of lubricant-infused surface
Authors: Kim Hae Nyeok , Kim Seung Joong , Choi Woorak , Sung Hyung Jin , Lee Sang Joon
Published: February 2021

A lubricant-infused surface (LIS) has been widely studied due to its potential in various industrial fields. However, the outermost lubricant layer of LIS is highly vulnerable to external shear force, which gradually degrades the slippery property. In this study, the shear flow-induced depletion of lubricant impregnated in a single cavity was experimentally investigated. The lubricant-filled three-dimensional cavity was exposed to a laminar channel flow. Temporal variations in the interfacial menisci inside the cavity were directly observed. The result showed that the depletion rate of lubricant is gradually decreased and eventually reaches a quasi-steady state after a long lapse of time. A large-scale vortex is formed near the lubricant meniscus and largely weakens the shear stress exerted on the meniscus. The formation of a large-scale vortex dramatically slows down the depletion rate of the impregnated lubricant. In addition, the effect of cavity geometry on the depletion of the lubricant impregnated in a biomimetic LIS was examined. The results revealed that a cavity with a smaller opening ratio (r/R) has better sustainability and less lubricant depletion. The present results would provide valuable insight into the design of a robust LIS system for effective and sustainable drag reduction and other applications.
Photoinduced trapping of charge at sulfur vacancies and copper ions in photorefractive Sn2P2S6 crystals
Authors: Gustafson T. D. , Golden E. M. , Scherrer E. M. , Giles N. C. , Grabar A. A. , Basun S. A. , Evans D. R. , Slagle J. E. , Halliburton L. E.
Published: February 2021

Electron paramagnetic resonance (EPR) is used to monitor photoinduced changes in the charge states of sulfur vacancies and Cu ions in tin hypothiodiphosphate. A Sn2P2S6 crystal containing Cu+ (3d10) ions at Sn2+ sites was grown by the chemical vapor transport method. Doubly ionized sulfur vacancies (VS2+) are also present in the as-grown crystal (where they serve as charge compensators for the Cu+ ions). For temperatures below 70 K, exposure to 532 or 633 nm laser light produces stable Cu2+ (3d9) ions, as electrons move from Cu+ ions to sulfur vacancies. A g matrix and a 63,65Cu hyperfine matrix are obtained from the angular dependence of the Cu2+ EPR spectrum. Paramagnetic singly ionized (VS+) and nonparamagnetic neutral (VS0) charge states of the sulfur vacancies, with one and two trapped electrons, respectively, are formed during the illumination. Above 70 K, the neutral vacancies (VS0) are thermally unstable and convert to VS+ vacancies by releasing an electron to the conduction band. These released electrons move back to Cu2+ ions and restore Cu+ ions. Analysis of isothermal decay curves acquired by monitoring the intensity of the Cu2+ EPR spectrum between 74 and 82 K, after removing the light, gives an activation energy of 194 meV for the release of an electron from a VS0 vacancy. Warming above 120 K destroys the VS+ vacancies and the remaining Cu2+ ions. The photoinduced EPR spectrum from a small concentration of unintentionally present Ni+ ions at Sn2+ sites is observed near 40 K in the Sn2P2S6 crystal.
Interference caused by electromagnetic interactions
Authors: Kolokolov A.A.
Published: February 2021

We consider interference fluxes of energy, momentum and angular momentum, describing the interaction of electric charges with constant and variable electromagnetic fields. Absorption and stimulated emission of atoms in the field of free and evanescent waves are described. It is shown that in the case of interaction with reactive fields, the momentum of an atom during absorption and stimulated emission does not change. A wave derivation of Planck’s formula based on the interference of the fields of classical thermal radiation and quantum zero-point oscillations is presented.
Optical fibre with an offset core for SBS suppression
Authors: Khudyakov M.M. , Alekseev V.V. , Lipatov D.S. , Guryanov A.N. , Temyanko V. , Bubnov M.M. , Likhachev M.E.
Published: February 2021

To raise the stimulated Brillouin scattering (SBS) threshold, we have fabricated an optical fibre having a core heavily doped with germanium oxide and displaced from the fibre axis. A method has been proposed for broadening the SBS gain spectrum of the fibre by winding it onto a small-diameter spool, and a broadening of the spectrum by 5.4 dB has been demonstrated, which indicates an increase in SBS threshold by 4.1 dB.
Spectral diagnostics of an optical discharge propagating along a hollow-core optical fibre
Authors: Bufetov I.A. , Kolyadin A.N. , Yatsenko Yu.P. , Kosolapov A.F.
Published: February 2021

The results of spectral diagnostics of an optical discharge (OD) plasma propagating through a hollow-core revolver fibre under the action of repetitively pulsed laser radiation are presented. The revolver fibre is made of silica glass, with a diameter of the hollow core being 20 μm. The peak values of the laser radiation intensity reach 1012 W cm−2at an average Nd : YAG laser power of about 2 W. The time-averaged spectrum of the OD plasma in the visible range has the form of a continuum and is close to the blackbody spectrum with a temperature of 13.3 – 17 kK. The form of the spectrum does not depend on the gas filling of the fibre core (air or argon). In the UV part of the spectrum, lines of neutral silicon are observed, which are indicative of the partial evaporation of the reflecting cladding of the fibre.
Microstructured optical fibres with a wide single-mode range
Authors: Denisov A.N. , Semjonov S.L.
Published: February 2021

We have proposed a new design of microstructured optical fibres (MOFs), containing three rings of identical circular holes around a core, with different separations between the rings. The properties of the MOFs have been analysed numerically using the finite element method (FEM), and the leakage loss in the spectral range 0.40 – 2.65 μm has been calculated for the fundamental and higher order modes at various parameters of the MOFs. We have demonstrated the presence of several local maxima in the spectral dependences of the leakage loss for higher order modes and examined the physical mechanism responsible for the formation of the maxima and the variation of their position with MOF parameters. It has been shown that the proposed MOF design allows for single-mode operation in the range 0.77 – 2.3 μm.
Cross-correlation of phase fluctuations measured with a point source and an incoherent luminous object
Authors: Botygina N.N. , Emaleev O.N. , Konyaev P.A. , Lukin V.P.
Published: February 2021

A high degree of cross-correlation of radiation wavefront aberrations, measured from a point reference source and from an extended object (a system of several luminous points), has been for the first time revealed based on simultaneous measurements of phase fluctuations in optical waves propagating in a turbulent atmosphere. The experimental data are consistent with analytical calculations. The high degree of cross-correlation (above 0.97) of measured phase fluctuations proves that an extended incoherent source can be used as a reference source to ensure the operation of an adaptive focusing system.
Zero ac Stark frequency shift of an atom trapped in pulsed laser light*
Authors: Afanasiev A.E. , Balykin V.I.
Published: February 2021

We report a theoretical analysis of the spectral properties of atoms localised in an optical pulsed trap. It is shown that this analysis can be carried out using the correlation coefficient calculated from the averaged dynamics of atomic excitation by resonant probe laser light in the presence of a nonresonant pulsed field. It follows from calculations that at a laser pulse duration of 8 ps, atoms can be trapped at a zero shift in the D2line transition frequency of the Rb atom, caused by the ac Stark effect. This configuration can be used to build optical frequency standards without the need for localising laser radiation at the ‘magic’ wavelength.
Laser adaptive vector-phase hydroacoustic measuring system
Authors: Romashko R.V. , Kulchin Yu.N. , Storozhenko D.V. , Bezruk M.N. , Dzyuba V.P.
Published: February 2021

We have developed and experimentally implemented an adaptive laser vector-phase hydroacoustic measuring system, which allows one to determine the total acoustic intensity vector. A receiving element of the measuring system comprises six spatially separated fibre-optic coil-type sensors. Signals from the sensors are phase demodulated by using a six-channel adaptive holographic interferometer based on dynamic holograms multiplexed in a photorefractive CdTe crystal. Performance of the developed measuring system has been experimentally tested by determining the bearing and localisation of a source of a weak hydroacoustic field.
LACC1 deficiency links juvenile arthritis with autophagy and metabolism in macrophages
Authors: Omarjee Ommar , Mathieu Anne-Laure , Quiniou Gaëlle , Moreews Marion , Ainouze Michelle , Frachette Cécile , Melki Isabelle , Dumaine Cécile , Gerfaud-Valentin Mathieu , Duquesne Agnès , Kallinich Tilmann , Tahir Turanli Eda , Malcus Christophe , Viel Sébastien , Pescarmona Rémi , Georgin-Lavialle Sophie , Jamilloux Yvan , Larbre Jean-Paul , Sarrabay Guillaume , Magnotti Flora , Rice Gillian I. , Bleicher Francoise , Reboulet Jonathan , Merabet Samir , Henry Thomas , Crow Yanick J. , Faure Mathias , Walzer Thierry , Belot Alexandre
Published: February 2021

Juvenile idiopathic arthritis is the most common chronic rheumatic disease in children, and its etiology remains poorly understood. Here, we explored four families with early-onset arthritis carrying homozygous loss-of-expression mutations in LACC1. To understand the link between LACC1 and inflammation, we performed a functional study of LACC1 in human immune cells. We showed that LACC1 was primarily expressed in macrophages upon mTOR signaling. We found that LACC1 deficiency had no obvious impact on inflammasome activation, type I interferon response, or NF-κB regulation. Using bimolecular fluorescence complementation and biochemical assays, we showed that autophagy-inducing proteins, RACK1 and AMPK, interacted with LACC1. Autophagy blockade in macrophages was associated with LACC1 cleavage and degradation. Moreover, LACC1 deficiency reduced autophagy flux in primary macrophages. This was associated with a defect in the accumulation of lipid droplets and mitochondrial respiration, suggesting that LACC1-dependent autophagy fuels macrophage bioenergetics metabolism. Altogether, LACC1 deficiency defines a novel form of genetically inherited juvenile arthritis associated with impaired autophagy in macrophages.
How Dissent on Gender Bias in Academia Affects Science and Society: Learning from the Case of Climate Change Denial
Authors: Leuschner Anna , Fernández Pinto Manuela
Published: February 2021

Gender bias is a recalcitrant problem in academia and society. However, dissent has been created on this issue. We focus on dissenting studies by Stephen J. Ceci and Wendy M. Williams, arguing that they reach conclusions that are unwarranted on the basis of the available evidence and that they ignore fundamental objections to their methodological decisions. Drawing on discussions from other contexts, particularly on manufactured dissent concerning anthropogenic climate change, we conclude that dissent on gender bias substantially contributes to (a) the exacerbation of biases in society and (b) an increasing number of attacks on researchers, making it both epistemically and socially problematic.
Hidden structure in the spectra of strongly correlated electrons in 1D
Authors: Quinn Eoin
Published: February 2021

We identify a structure in the spectra of 1D lattice models of interacting electrons, characterised by an anomalous gapped branch of elementary excitations. Focussing on a family of Bethe ansatz solvable models, where all excitations are stable against decay, we make a four-way classification of the energy spectrum along with a model belonging to each class. We find in particular that the anomalous excitation branch may switch between the spin and charge symmetry sectors without a change in the ground state. Instead it changes its nature by becoming inaccessible to the ground state.
Features of the fine structure of asymmetric TE and TM modes
Authors: Egorov Yu A , Bretsko M V , Akimova Ya E , Volyar A V
Published: February 2021

This work is devoted to a new section of singular optics supplying a fractional topological charge on the axis. The peculiarity of this type of beams is structural instability. With a small external perturbation, these beams form optical arrays. Such optical vortices can be connected and, as it were, form an integral picture, or decay during propagation due to the fact that each of the vortices receives an additional phase swell. These studies were based on an experimental study and theoretical calculation of beams with a vector structure. And transporting optical vortices with a topological fractional charge, which is evidence of the formation of asymmetric TM (transverse magnetic) and TE (transverse electric) modes in free space. Some features of their vector “thin” structures have been studied in free space.
Development of optical imaging formation system for research of magnetic track parameters from moving object
Authors: Logunov S E , Davydov V V , Yu Rud V
Published: February 2021

The necessity of the magnetic track research from the moving object is substantiated. An optical system has been developed to detect a magnetic track at sea depth from the moving magnetic object. A method of processing and decoding optical images formed using a ferrofluid cell and laser radiation is proposed. The results of experimental studies are presented.
Improved 3D imaging of phase shifting digital holographic microscope by compensation for wavefront distortion
Authors: Cazac V
Published: February 2021

This paper is focused on improving the performance of quantitative phase imaging via phase-shifting digital holographic microscope. The development of the interferometric techniques is important for technology and biomedicine, since the surface and structure of samples can be monitored in real-time by non-destructive investigations. The novelty of the optical arrangement is that in the reference beam of the digital holographic microscope a liquid crystal variable retarder is introduced. Thus, it became possible to actively control the polarization state of light for realizing the necessary phase-shifts. In addition, a spatial light modulator is integrated in the optical setup to produce computer-controlled compensation of the spatial distortion. An ad hoc hologram processing technique was developed to execute the numerical correction of the physical phase-shifting errors. Topographical investigations of phase masks recorded on carbazol-based azopolymers provided the experimental testing of the achieved accuracy in phase reconstruction.
Modeling the image obtained by a system of vortex harmonic lenses
Authors: Khokhlov A S , Skidanov R V
Published: February 2021

The possibility of obtaining images using a system based on vortex diffraction lenses is considered. A system of two vortex harmonic lenses was simulated. In the system the total intensity distribution was calculated using the Fresnel transform. The width of the point spread function, which is 66 μm, is obtained. The influence of spatial filters on the result of this system is considered.
Tools for promoting a scientific article: Computer Optics journal case study
Authors: Kudryashov D V
Published: February 2021

The author analyzes the main tools for promoting scientific articles that are used most often by the editorial board of the Computer Optics journal to promote the publication in international scientometric databases and popularize the ideas of science. It is noted that the use of these tools allowed the publication to increase significantly the “portfolio” of articles, the number of articles published per year, including the articles in English, increase significantly the citation of journal articles in other scientific publications, as well as expand the geographical spread of authors.
Computer Information System multi-criteria optimization conditions of the complex chemical processes
Authors: Koledina K F , Koledin S N
Published: February 2021

An information-computing system for multi-criteria optimization of complex chemical processes has been developed. Considered sensing algorithm for solving the problem of multicriteria optimization. Information and computing system combines subsystems for solving individual computing problems. Each subsystem is designed for separate calculations-direct kinetic task, calculation of the inverse kinetic problem, multi-criteria optimization of the reaction conditions. For the catalytic reaction of the benzylalkyl ethers synthesis, using the developed information-computational system, the problem of optimizing the conditions has been solved. Based on the kinetic model, the optimal values of temperature and reaction time are determined. The values of the parameters for assessing the quality of the Pareto approximation are calculated.
Modeling of thermoelectric processes in a power MOSFET transistor with a structural defect
Authors: Sergeev V A , Hodakov A M , Kulikov A A
Published: February 2021

The results of thermal modeling of the temperature distribution in the structures of a high-power MOSFET transistor with macrodefects of an electrophysical nature are presented. It is shown that the presence of a defect in the structure of the transistor leads to an increase in the maximum temperature of the channel overheating and an increase in the inhomogeneity of the temperature distribution over the area of the active region of the crystal. The influence of the location of the defect on the value of the maximum overheating of the structure and the gate-source voltage is considered. The developed thermal model can serve as the basis for creating methods for diagnosing MOSFET transistors by thermoelectric characteristics and identifying defective products.
Software complex for modeling and optimization of chemical processes kinetics
Authors: Koledina K F , Almakaev R R , Koledin S N
Published: February 2021

A program is designed to optimize chemical reactions, allowing to carry out modeling and optimization of catalytic reactions has been developed. Implemented export and import of the reaction model and calculation of the direct kinetic problem. As an object of study, the catalytic reaction of the synthesis of benzyl butyl ether is considered. A mathematical reaction model is given and the concentrations of all reaction components are calculated.
Analytical and numerical modelling of the programmable percolation route formation when planning two-phase operations
Authors: Mostovoi Y A , Berdnikov V A
Published: February 2021

A swarm of robots, as a system of relatively simple interconnected managed objects, performs a common task simultaneously and in a distributed manner. When planning swarm operations associated with the creation in the service area through the front strip of the zones of the trust instrument - payload objects swarm, there is a problem of transmitting a signal from one robot to another for operational rearrangement of the swarm, as at the time of planning the exact purpose of the swarm operation has not yet been determined, or is a secret, or is determined by a number of random circumstances. The execution of the swarm operation is advisable to carry out in two phases, and the first phase to start even before the resolution of these uncertainties by creating a basic random network with a small concentration of robots in it. In the second phase of the operation, a programmable percolation route is formed by local rearrangement of the robots, which provides target coverage of the target equipment of the swarm objects of a certain service zone. In this case, you can significantly reduce the time of the operation. The corresponding analytical dependences were obtained.
Determination of heat exchange coefficient in heat conductivity problems with asymmetric boundary conditions
Authors: Trubitsyn K V , Mikheeva G V , Klebleev R M , Stefanyuk E V
Published: February 2021

This paper depicts an approximate analytical solution of the non-stationary heat conduction problem for an infinite plate under asymmetric boundary conditions of the third kind according to the heat balance integral method. The solution is a simple, engineering-friendly product of exponential and coordinate functions. The coordinate functions are found by the method of undetermined coefficients so that the asymmetric boundary conditions of the third kind meet the main criteria primarily. Satisfactory accuracy of the obtained solution for engineering use is provided by residual orthogonality condition abidance of the differential equation to the coordinate function obtained in this research. This method allows for errors by no more than 1% in the second approximation, in the range 1.0 < Fo < ∞ for Bi = 0 and Bi2 = 0.1. The heat transfer coefficient was determined a plate surface using the named solution along with data on the temperature change at a fixed plate spot, thus solving the inverse heat conductivity problem.
Comparative analysis of simulation options for the real geometry of the surfaces of gas turbine engine parts
Authors: Grachev I A , Bolotov M A , Pechenin V A , Kudashov E V , Kharin K E
Published: February 2021

Geometric deviations of parts surfaces inevitably occur during parts manufacture. It is known that the accumulated defects of parts surfaces and assembly units impact their functional characteristics throughout the entire product life cycle. Often, assembly simulation and dimensional ties analysis of products are performed by using the nominal geometry of parts without taking into account geometric deviations of the shape and location of parts surfaces. The accuracy of dimensional analysis without taking into account geometric deviations of the shape and location of parts surfaces is not sufficient to solve technological problems in digital production. The purpose of this article is the study of the influence of methods and models for constructing the real geometry on the accuracy of its reproduction. The subject of the research is the assembly unit of the rotor of a low-pressure turbine of an aircraft engine. The article considers three methods for constructing the real geometry, which are used to realize assembly virtual simulation. Comparative results of assembly simulation with the use of considered methods of real geometry constructing are presented, as well as their influence on the controlled assembly parameters is estimated.
Mathematical modeling of the process of interaction of sulfur dioxide with pyrolyzed polyacrylonitrile
Authors: Kakorina O A , Zaporotskova I V , Kakorin I A
Published: February 2021

The paper presents a study of the interaction of sulfur dioxide with a polymer-pyrolyzed polyacrylonitrile (PPAN). The possibility of using PPAN as an element of an electronic sensor device for recording the presence and identification of sulfur dioxide in the atmosphere is shown. The results of the established geometric and electron-energy characteristics of the polymer interacting with gas are described. Theoretical calculations were performed using the molecular cluster model and the quantum-chemical MNDO method.
Synergetic control algorithms for a multidimensional biomedical model under conditions of nonrandom and random disturbances using kernel regression
Authors: Kolesnikova S I , Avramyonok V A
Published: February 2021

The purpose is to investigate the applicability of the principles of the synergetic control theory to a primitive object with the initial description in the form of a system of nonlinear differential equations with a delay. In terms of intensionality, control will be here understood as the rule of intake of the substance (agent) into a living organism, which serve as antidotes to a disease, in the form of a pair of variables (time of the substance administration and amount of the administered substance). Based on a new algorithm of a discrete nonlinear analytical synthesis, three systems of control over such an object are designed for the following cases: 1) a control object is functioning under completely determined conditions; 2) a control object is affected by the deterministic unknown constrained disturbances via the control variable; 3) presence of an additive random noise on any variable. The results of a comparative numerical modeling of the designed control systems are presented, which function without any preliminary filtration of the random variable measurements and with a filtration by a kernel regression algorithm. The results can be used in the decision support systems.
Digital model of polymer molecules
Authors: Zaitsev S A , Semenov M E , Meleshenko P A , Tikhomirov S G , Chernyaev A P
Published: February 2021

The article is devoted to the construction and analysis of a digital model of polymer molecules. In this regard, the pseudo-random value generator (the Mersenne Vortex) from the C++ library of the C++11 standard was investigated. A method for spatial modelling of a polymer chain with free and fixed valence angles is developed and described. A software for building polymer molecules with given parameters is implemented within C++. A program for visualization of polymer structures is implemented in C#. Fractal dimensions for polymer chains with different stochastic properties were calculated. The basis for the further development of the software for simulation of radiolysis of polymers has been introduced.
Higher-order coefficients of the Williams series expansion for near crack-tip fields and their extraction from FEM experiments and digital photoelasticity method
Authors: Stepanova L V
Published: February 2021

Multi-parameter stress field near the Mode I crack tip in an isotropic linear elastic material is presented. The coefficients of the Williams series expansion of the stress field in the vicinity of the Mode I crack in the isotropic linear elastic material are obtained by the digital photoelasticity technique and by finite element analysis. The main objective of this study is to determine first fifteen coefficients with good accuracy and to compare the numerical results with the analytical solution for the infinite plate with the central crack. It is shown that the coefficients of the higher-order terms of the Williams series expansion are extracted with good accuracy. Comparison of the coefficients of the Williams series known from the theoretical solution for an infinite plate with the central crack and the coefficients extracted from the photoelasticity method and from finite element analysis is given. The FEM analysis is performed for a series of cracked specimens with a small crack and for a series of cracked specimens considered in the phototelasticity experiments. It is shown significant importance of higher-order terms in the Williams series expansion.
Modeling of soil dumping based on a modified Upwind Leapfrog difference scheme
Authors: Sukhinov A I , Chistyakov A E , Kuznetsova I Y , Protsenko E A , Atayan A M
Published: February 2021

The difference scheme is developed for the diffusion-convection problem numerical solution at large grid Peclet numbers. The scheme based on linear combination of the Upwind and Standard Leapfrog difference schemes (LCUSLDS) with weight coefficients obtained by minimizing the approximation error at small Courant numbers. The proposed approach takes into account the function of cell fullness, which allows to increase the accuracy of modeling on the area with complex geometry. The proposed modification of the Upwind Leapfrog difference scheme for the diffusion-convection problem numerical solution has better accuracy compared to other schemes considered in the article for grid values of Peclet numbers in the range 2 ≤ Pe ≤ 20. The problem of substances transport between two coaxial cylinders for large and small values of grid Peclet numbers is considered to test the proposed difference scheme. This movement of the water medium in hydrodynamics is called the Couette-Taylor flow. The steady fluid flow between two infinitely long coaxial circular cylinders is considered.
Sphalerons from the minimal 331 model and baryogenesis
Authors: Boubakir A , Aissaoui H , Mebarki N
Published: February 2021

The sphaleron energy and rate are investigated within the minimal 331 model. It is shown, that the constraint leading to the first order phase transition is satisfied for both spontaneous symmetry breaking vacuums of the model. A comparison with the economical model study is also made.
Ultra high energy cosmic rays
Authors: Attallah R.
Published: February 2021

Ultra high energy cosmic rays are the highest-energy particles ever observed in nature. Although known for more than half a century, their origin is still baffling scientists. They are most likely linked to some of the most violent phenomena in the universe but the nature of their sources remains a mystery, and so does the physical mechanism to accelerate particles to extreme energies. Here we review the different aspects of ultrahigh energy cosmic rays, emphasizing the key achievements over the past decade in our understanding of their origin. We also give a brief account of upcoming experiments and the prospects of progress in this field of research.
Dynamical study of ellipsoidal universes
Authors: Abdelali M L , Mebarki N
Published: February 2021

A Universe containing uniform magnetic fields, strings, or domain walls is shown to have an ellipsoidal expansion. This case is motivated from observational cosmology, especially the anomaly concerning the low quadrupole amplitude compared to the best-fit ΛCDM prediction in WMAP data. It is shown that a Universe with eccentricity at decoupling of order 10−2 can reduce the quadrupole amplitude without affecting higher multipoles of the angular power spectrum of the temperature anisotropy. The evolution of ellipsoidal Universes is studied using dynamical system techniques for the first time. The determined critical points vary between saddle and past attractors depending on dark energy state equation parameter w
Λ, with no future attractors. Numerical integrations of this dynamical system done using several initial conditions are showing new important results. For instance, a tendency for high expansion differences between planar and perpendicular axes is observed which contradicts previous assumptions on the evolution behaviour of ellipsoid Universes.
TCAD simulation of small-pitch 3D sensors for pixel detector upgrades at High Luminosity LHC
Authors: Boughedda A , Lakhdara M , Latreche S , Mendicino R , Dalla Betta G F
Published: February 2021

Applications at the High Luminosity LHC (HL-LHC) have required the development of a new generation of 3D pixel sensors with increased pixel granularity, extreme radiation hardness and low material budget. To this purpose, new 3D pixels have small pitch (e.g., 50×50 or 25×100 μm2) and reduced active thickness (∼100 μm). Owing to the small inter-electrode spacing (∼28 μm in the most aggressive designs). These 3D pixels are expected to be radiation hard even after irradiation at the hadron fluences. Indeed, they are of interest for the innermost tracking layers of ATLAS and CMS (∼2×1016 neq cm−2), and beyond. In order to estimate the charge collection efficiency (CCE) after irradiation, TCAD simulations can be conveniently used, providing useful information for the optimization of sensor design and fabrication technology. Within the AIDA-2020 project, with reference to the new single-sided 3D technology from FBK (Trento, Italy), we have simulated the CCE of pixel sensors with different inter-electrode spacing irradiated at different fluences. For these simulations, a 2D domain was used, consisting of a horizontal slice taken at half the depth of a 3D sensor. Simulations consider the hit of a minimum ionizing particle, described by the Heavy Ion model at different points within the active area. In addition, bulk radiation damage is accounted by using advanced deep-level trap models. This paper reports a comprehensive description of the simulation results based on a radiation model validated by comparison to experimental results from n-in-p strip detectors at 248 K and 900 V bias.
Explaining B decays anomalies in SUSY models
Authors: Boubaa Dris , Khalil Shaaban , Moretti Stefano
Published: February 2021

Recent measurements of certain B decays indicate deviations from Standard Model (SM) predictions. We show that Supersymmetric effects can increase the Branching Ratios (BRs) of both B → Dτντ
and B → D*τντ
with respect to the SM rates, thereby approaching their newest experimentally measured values.
Lepton flavor universality violation in a 331 model in b → sl
+
l
− processes
Authors: Lebbal S , Mebarki N , Mimouni J
Published: February 2021

Lepton Flavor Universality Violation (LFUV) in b → sl
+
l
− processes is investigated in the context of a 331 model. It is shown that in order to explain the experimentally observed deviations from the Standard Model in these FCNC transitions, a non-minimal version of the model has to be considered. We investigate the ability of this model in accommodating the model-independent scenarios currently favored by global fits.
Real time ultrasoft fermion self energy at next to-leading order in hot QED
Authors: Bouakaz Karima , Abada Abdessamad
Published: February 2021

Subsequent studies of the behavior of the gluon and quark damping rates in the imaginary-time formalism have indicated that there are difficulties in the infrared sector [1, 2, 3, 4, 5, 6, 7]. To look further into the infrared behavior, we propose to calculate the next-to-leading order dispersion relations for slow-moving Fermions at high-temperature quantum electrodynamics (QED) in real-time formalism. We determine a compact analytic expression for the complete next-to-leading contribution to the retarded fermion self-energy with ultrasoft momentum in the framework of hard-thermal-loop (HTL)-summed perturbation of massless QED at high temperature. The calculation is done using real-time formalism. The next-to-leading order fermion self-energy is written in terms of three and four HTL-dressed vertex functions. The real part and the opposite of the imaginary part of the retarded fermion self-energy are related to the next-to-leading order contributions of energy and damping rate respectively.
Compiling single-qubit braiding gate for Fibonacci anyons topological quantum computation
Authors: Rouabah M T , Belaloui N E , Tounsi A
Published: February 2021

Topological quantum computation is an implementation of a quantum computer in a way that radically reduces decoherence. Topological qubits are encoded in the topological evolution of two-dimensional quasi-particles called anyons and universal set of quantum gates can be constructed by braiding these anyons yielding to a topologically protected circuit model. In the present study we remind the basics of this emerging quantum computation scheme and illustrate how a topological qubit built with three Fibonacci anyons might be adopted to achieve leakage free braiding gate by exchanging the anyons composing it. A single-qubit braiding gate that approximates the Hadamard quantum gate to a certain accuracy is numerically implemented using a brute force search method. The algorithms utilized for that purpose are explained and the numerical programs are publicly shared for reproduction and further use.
Experimental Study Via Dynamic Prediction Model on High Pressure Hydraulic Slotting and High Efficiency Gas Drainage Technology under Complex Geological Conditions
Authors: Li Chengcheng
Published: February 2021

In view of the difficult problem of dynamic disaster prevention and control in deep high gas, high stress and low permeability coal seam, the change law of drilling stress after seam cutting through drilling and bedding drilling is revealed by using numerical simulation method. The high-pressure hydraulic slotting method is used in Xinji Mining Area to carry out pressure relief and permeability increase test on coal seams. The test results are as follows: the slotting radius reaches 2.5m, and the net amount of gas extraction is 4.5 times higher than that of ordinary drilling holes, so as to realize efficient gas extraction in coal seams and reduce the risk of coal seam outburst. The technology of high-pressure hydraulic slotting, pressure relief and permeability enhancement can be used as a supplementary means for the prevention and control of coal seam dynamic disasters in deep mines.
Architecture and Design of Oracle Scheduler
Authors: Liu Jimin
Published: February 2021

Oracle scheduler focuses on the automatic management, maintenance and monitoring of Oracle database jobs. Through it, many routine database tasks can be automatically executed, and human intervention can be reduced, so as to improve the efficiency of system operation and implement more flexible and complex task management. This paper introduces the concept and classification of Oracle scheduler, analyzes each component of Oracle scheduler, explains its overall architecture and tasks of different components, summarizes the problems needing attention in design according to design experience, and illustrates its application through the creation of Oracle scheduler object instance, job scheduling and evaluation of execution frequency.
An Intelligent Obstacle Avoidance Method in Unmanned Driving
Authors: Li Jinze , Liu Qinrui , Dong Hui , Wu Maowei
Published: February 2021

This paper proposes an intelligent obstacle avoidance method in unmanned driving. This method first establishes a simplified model for the obstacle avoidance problem in unmanned driving, and constrains the car from kinematics, physics, travelable area, and critical collision. Then list the equations and uses the direct collocation method to discrete the equation. The problem is turned into a nonlinear programming problem.
Exploration & Research on Distance Education System Based on Blockchain Technology
Authors: Liu Xiaogang
Published: February 2021

In this paper, it mainly explores and studies the distance education system based on blockchain technology according to the characteristics of blockchain technology, such as “decentralization, de-trust, non-tampering and traceability”, etc. First of all, it designed a multi-layer logical structure; Second, it proposed an improved DPoS consensus mechanism; Third, it analyzed the generation steps of the blockchain in the system and the functional process of the consensus mechanism. As a result, by using the distance education system based on blockchain technology, the distance education centers distributed all over China can not only strengthen the sharing of teaching resources and improve the management efficiency, but also better improve the safety and transparency of their teaching, scientific research and management.
Research on Efficient Retrieval Technology of Optical Characteristics of Image Resources in Digital Library
Authors: Zhao Guotao , Ding Jie , Li Honglai , Xu Fang
Published: February 2021

In order to improve the intelligence of digital library image resources, this paper proposes an efficient retrieval technology of digital library image resources based on deep learning and semantic feature extraction, which uses infrared and radio frequency transverse scanning technology to scan the front cover and back cover of digital library image resources, and divides the text and image regions of scanned digital library image resources infrared and radio frequency images. In the infrared and radio frequency transmission space, the collected scanned image resources of digital library are subjected to semantic diversification feature decomposition and feature separation, and the binary semantic ontology information features of digital library image resources are extracted. Combined with the image semantic feature extraction method, the convergence control in the process of extracting the structural features of digital library image resources is realized, and the digital library image resources are retrieved based on the extracted library resource information feature components. Simulation results show that this method has higher precision and shorter retrieval time, which improves the retrieval efficiency of digital library.
Research on Optimization of Multi-AGV Path Based on Genetic Algorithm Considering Charge Utilization
Authors: Wang Jianjun , Pan Junnan , Huo Jikun , Wang Ran , Li Li , Nian Tiantian
Published: February 2021

The rapid development of e-commerce and artificial intelligence technology has led to the rapid development of unmanned warehousing automation technology in the logistics industry. Unmanned warehousing and automated guided vehicle (AGV) equipment in unmanned warehousing have also increased. Since the AGV needs to be charged, based on the traditional simple path optimization, if the sorting efficiency of logistics needs to be further improved, the charging problem of the AGV needs to be considered. This paper constructs a multi-AGV path optimization model in an unmanned storage environment based on the charging utilization rate. The model takes the shortest path and the highest charging utilization rate as the dual goals, and selects the genetic algorithm as the method to solve the model, which is verified by simulation experiments. The proposed model and algorithm have certain validity and feasibility.
Early Warning about Coal Mine Safety Based on Improved PNN-DS Evidence Theory
Authors: Wang Yuanbin , Zhou Chong
Published: February 2021

This paper establishes a two-level information fusion model based on improved probabilistic neural network and DS evidence theory to achieve the purpose of early warning of coal mine safety risk levels and apply the principle of information fusion to safety early warning problems. Firstly, this paper improves the traditional probabilistic neural network is improved in this paper. Then, input the sample data the sample data is input into the improved probabilistic neural network to obtain the basic probability assignment. Finally, the output of the neural network is fused by DS evidence theory. The historical data of a coal mine work face are trained and tested by MATLAB. The results show that the model established in this paper has a higher prediction accuracy, and realizes the purpose of early warning of coal mine safety risk level better, which has is meaningful and significant for the safety management of coal mine.