bluuebunny/crossref_metadata_2025 huggingface dataset:
Vesicular nucleotide transporter is a molecular target of eicosapentaenoic acid for neuropathic and inflammatory pain treatment
Authors: Kato Yuri , Ohsugi Kengo , Fukuno Yuto , Iwatsuki Ken , Harada Yuika , Miyaji Takaaki
Published: July 2022

Eicosapentaenoic acid (EPA), an omega-3 (ω-3) polyunsaturated fatty acid, is an essential nutrient that exhibits antiinflammatory, neuroprotective, and cardiovascular-protective activities. Although EPA is used as a nutrient-based pharmaceutical agent or dietary supplement, its molecular target(s) is debatable. Here, we showed that EPA and its metabolites strongly and reversibly inhibit vesicular nucleotide transporter (VNUT), a key molecule for vesicular storage and release of adenosine triphosphate (ATP) in purinergic chemical transmission. In vitro analysis showed that EPA inhibits human VNUT-mediated ATP uptake at a half-maximal inhibitory concentration (IC
50
) of 67 nM, acting as an allosteric modulator through competition with Cl
−
. EPA impaired vesicular ATP release from neurons without affecting the vesicular release of other neurotransmitters. In vivo,

VNUT
−/−

mice showed a delay in the onset of neuropathic pain and resistance to both neuropathic and inflammatory pain. EPA potently attenuated neuropathic and inflammatory pain in wild-type mice but not in

VNUT
−/−

mice without affecting the basal nociception. The analgesic effect of EPA was canceled by the intrathecal injection of purinoceptor agonists and was stronger than that of existing drugs used for neuropathic pain treatment, with few side effects. Neuropathic pain impaired insulin sensitivity in previous studies, which was improved by EPA in the wild-type mice but not in the

VNUT
−/−

mice. Our results showed that VNUT is a molecular target of EPA that attenuates neuropathic and inflammatory pain and insulin resistance. EPA may represent a unique nutrient-based treatment and prevention strategy for neurological, immunological, and metabolic diseases by targeting purinergic chemical transmission.
Orchestrated translation specializes dinoflagellate metabolism three times per day
Authors: Bowazolo Carl , Song Bo , Dorion Sonia , Beauchemin Mathieu , Chevrier Samuel , Rivoal Jean , Morse David
Published: July 2022

Many cells specialize for different metabolic tasks at different times over their normal ZT cycle by changes in gene expression. However, in most cases, circadian gene expression has been assessed at the mRNA accumulation level, which may not faithfully reflect protein synthesis rates. Here, we use ribosome profiling in the dinoflagellate
Lingulodinium polyedra
to identify thousands of transcripts showing coordinated translation. All of the components in carbon fixation are concurrently regulated at ZT0, predicting the known rhythm of carbon fixation, and many enzymes involved in DNA replication are concurrently regulated at ZT12, also predicting the known rhythm in this process. Most of the enzymes in glycolysis and the TCA cycle are also regulated together, suggesting rhythms in these processes as well. Surprisingly, a third cluster of transcripts show peak translation at approximately ZT16, and these transcripts encode enzymes involved in transcription, translation, and amino acid biosynthesis. The latter has physiological consequences, as measured free amino acid levels increase at night and thus represent a previously undocumented rhythm in this model. Our results suggest that ribosome profiling may be a more accurate predictor of changed metabolic state than transcriptomics.
Proximity interactome analysis of Lassa polymerase reveals eRF3a/GSPT1 as a druggable target for host-directed antivirals
Authors: Fang Jingru , Pietzsch Colette , Witwit Haydar , Tsaprailis George , Crynen Gogce , Cho Kelvin Frank , Ting Alice Y. , Bukreyev Alexander , Saphire Erica Ollmann , de la Torre Juan Carlos
Published: July 2022

Completion of the Lassa virus (LASV) life cycle critically depends on the activities of the virally encoded, RNA-dependent RNA polymerase in replication and transcription of the viral RNA genome in the cytoplasm of infected cells. The contribution of cellular proteins to these processes remains unclear. Here, we applied proximity proteomics to define the interactome of LASV polymerase in cells under conditions that recreate LASV RNA synthesis. We engineered a LASV polymerase-biotin ligase (TurboID) fusion protein that retained polymerase activity and successfully biotinylated the proximal proteome, which allowed the identification of 42 high-confidence LASV polymerase interactors. We subsequently performed a small interfering RNA (siRNA) screen to identify those interactors that have functional roles in authentic LASV infection. As proof of principle, we characterized eukaryotic peptide chain release factor subunit 3a (eRF3a/GSPT1), which we found to be a proviral factor that physically associates with LASV polymerase. Targeted degradation of GSPT1 by a small-molecule drug candidate, CC-90009, resulted in strong inhibition of LASV infection in cultured cells. Our work demonstrates the feasibility of using proximity proteomics to illuminate and characterize yet-to-be-defined host-pathogen interactome, which can reveal new biology and uncover novel targets for the development of antivirals against highly pathogenic RNA viruses.
Collective interlayer pairing and pair superfluidity in vertically stacked layers of dipolar excitons
Authors: Zimmerman Michal , Rapaport Ronen , Gazit Snir
Published: July 2022

Layered bosonic dipolar fluids have been suggested to host a condensate of interlayer molecular bound states. However, experimental observation has remained elusive. Motivated by two recent experimental works [C. Hubertet al.,Phys. Rev. X9, 021026 (2019) and D. J. Choksyet al.,Phys. Rev. B103, 045126 (2021)], we theoretically study, using numerically exact quantum Monte Carlo calculations, the experimental signatures of collective interlayer pairing in vertically stacked indirect exciton (IX) layers. We find that IX energy shifts associated with each layer evolve nontrivially as a function of density imbalance following a nonmonotonic trend with a jump discontinuity at density balance, identified with the interlayer IX molecule gap. This behavior discriminates between the superfluidity of interlayer bound pairs and independent dipole condensation in distinct layers. Considering finite temperature and finite density imbalance conditions, we find a cascade of Berezinskii–Kosterlitz–Thouless (BKT) transitions, initially into a pair superfluid and only then, at lower temperatures, into complete superfluidity of both layers. Our results may provide a theoretical interpretation of existing experimental observations in GaAs double quantum well (DQW) bilayer structures. Furthermore, to optimize the visibility of pairing dynamics in future studies, we present an analysis suggesting realistic experimental settings in GaAs and transition metal dichalcogenide (TMD) bilayer DQW heterostructures where collective interlayer pairing and pair superfluidity can be clearly observed.
Disproportionate investment in Spiralin B production limits in-host growth and favors the vertical transmission of
Spiroplasma
insect endosymbionts
Authors: Masson Florent , Rommelaere Samuel , Schüpfer Fanny , Boquete Jean-Philippe , Lemaitre Bruno
Published: July 2022

Insects frequently harbor endosymbionts, which are bacteria housed within host tissues. These associations are stably maintained over evolutionary timescales through vertical transmission of endosymbionts from host mothers to their offspring. Some endosymbionts manipulate host reproduction to facilitate spread within natural populations. Consequently, such infections have major impacts on insect physiology and evolution. However, technical hurdles have limited our understanding of the molecular mechanisms underlying such insect–endosymbiont interactions. Here, we investigate the nutritional interactions between endosymbiotic partners using the tractable insect
Drosophila melanogaster
and its natural endosymbiont
Spiroplasma poulsonii
. Using a combination of functional assays, metabolomics, and proteomics, we show that the abundance and amino acid composition of a single
Spiroplasma
membrane lectin, Spiralin B (SpiB), dictates the amino acid requirements of the endosymbiont and determines its proliferation within host tissues. Ectopically increasing SpiB levels in host tissues disrupts localization of endosymbionts in the fly egg chambers and decreases vertical transmission. We find that SpiB is likely to be required by the endosymbiont to enter host oocytes, which may explain the massive investment of
S. poulsonii
in SpiB synthesis. SpiB both permits vertical transmission of the symbiont and limits its growth in nutrient-limiting conditions for the host; therefore, a single protein plays a pivotal role in ensuring durability of the interaction in a variable environment.
Tandem interaction enhancement
Authors: Nuzzo Elena
Published: July 2022

This chapter discusses the applicability of the construct of focus on form, one of Michael Long’s most prominent contributions to the field of instructed second language acquisition, in the very particular context of tandem learning. In tandem interactions, two partners learning each other’s language assume in turn the role of the native-speaker teacher. These low-structured learning environments would benefit from the implementation of focus-on-form pedagogical procedures including, but not limited to, corrective feedback. An external manipulation on the part of the tandem organizer, which I call ‘interaction enhancement’, is needed to push the partners to systematically and confidently apply focus-on-form techniques to their exchanges.
Immediate versus delayed oral negative feedback
Authors: Granena Gisela , Yilmaz Yucel
Published: July 2022

Long’s Interaction Hypothesis (1981, 1983) provides a theoretical framework for understanding how interaction can contribute to second language (L2) acquisition. Specifically, negative feedback provided during interaction is viewed as a feature that can facilitate L2 development by drawing learners’ attention to problematic forms (Long, 1996). Long’s influential hypotheses were originally formulated in the context of face-to-face conversational interaction and, therefore, negative feedback was understood as feedback that is provided immediately to the learner in oral conversation. However, negative feedback cannot always be provided immediately to L2 learners. In distance language learning settings where the L2 is learned online and where communication between learner and instructor may take place asynchronously, feedback cannot be provided during a communicative task and it is provided at a later time, for example, at the end of a teaching unit.
A controversial issue: Can mitochondria modulate cytosolic calcium and contraction of skeletal muscle fibers?
Authors: Reggiani Carlo , Marcucci Lorenzo
Published: July 2022

Mitochondria are characterized by a high capacity to accumulate calcium thanks to the electrochemical gradient created by the extrusion of protons in the respiratory chain. Thereby calcium can enter crossing the inner mitochondrial membrane via MCU complex, a high-capacity, low-affinity transport mechanism. Calcium uptake serves numerous purposes, among them the regulation of three dehydrogenases of the citric cycle, apoptosis via permeability transition, and, in some cell types, modulation of cytosolic calcium transients. This Review is focused on mitochondrial calcium uptake in skeletal muscle fibers and aims to reanalyze its functional impact. In particular, we ask whether mitochondrial calcium uptake is relevant for the control of cytosolic calcium transients and therefore of contractile performance. Recent data suggest that this may be the case, at least in particular conditions, as modified expression of MCU complex subunits or of proteins involved in mitochondrial dynamics and ablation of the main cytosolic calcium buffer, parvalbumin.
Bayesian analysis of nuclear polarizability corrections to the Lamb shift of muonic H-atoms and He-ions
Authors: Li Muli S S , Acharya B , Hernandez O J , Bacca S
Published: July 2022

The extraction of nuclear charge radii from spectroscopy experiments in muonic atoms is currently limited by the large uncertainties associated with the theoretical evaluation of the nuclear polarizability effects. To facilitate calculations, these polarizability corrections are conventionally expressed as an expansion in a dimensionless parameter η, which has been argued in previous literature to hold an approximate value of 0.33 in light-nuclear systems. In this work, we check this claim by doing a Bayesian analysis of the nuclear-polarizability corrections to the Lamb shift in μ
2H and μ
3H atoms and in μ
3He+ and μ
4He+ ions at various orders in the η-expansion. Our analysis supports the claim that η ≪ 1 in these systems and finds truncation uncertainties that are similar to the previous estimate, the only exception being the truncation uncertainties in the μ
3He+ ion, which are found to be larger.
The optimal placement of piezoelectric actuator and sensor for active structural noise control of plates
Authors: Wu Tao , Chen Zhaobo , Qu Jianjun , Yu Dong
Published: July 2022

The location optimization of actuators and sensors is a very important step when applying Active Structure Acoustic Control to practical engineering. A good actuator arrangement not only achieves a more effective control effect, but also reduces the required control energy, and a good sensor arrangement can help to collect more obvious and useful information. However, in some commonly used optimization programs, the influence of noise radiation is often ignored and only the controllability of structural vibration is concerned, which may cause the control force to control some modes with low noise radiation, but the modes that need to be controlled cannot be controlled. Therefore, this paper proposes a location optimization method of piezoelectric actuators and sensors in active noise control based on acoustic radiation, and formulates a new cost function, that is, the acoustic power is added as a weight function to the optimization criterion, so that the control energy can control these strong radiation modes as much as possible; at the same time, the Multi-Verse Optimizer algorithm is also improved, and through the optimization of the wormhole existence probability and travelling distance rate, the global search ability of the algorithm is improved to avoid the algorithm from entering the local in-depth development. In addition, the MVO algorithm suitable for continuous variables is discretized to adapt to the optimization problem in this paper.
The Visual Survey Group: A Decade of Hunting Exoplanets and Unusual Stellar Events with Space-based Telescopes
Authors: Kristiansen Martti H. K. , Rappaport Saul A. , Vanderburg Andrew M. , Jacobs Thomas L. , Martin Schwengeler Hans , Gagliano Robert , Terentev Ivan A. , LaCourse Daryll M. , Omohundro Mark R. , Schmitt Allan R. , Powell Brian P. , Kostov Veselin B.
Published: July 2022

This article presents the history of the Visual Survey Group (VSG)—a Professional-Amateur (Pro-Am) collaboration within the field of astronomy working on data from several space missions (Kepler, K2 and Transiting Exoplanet Survey Satellite). This paper covers the formation of the VSG, its survey-methods including the most common tools used and its discoveries made over the past decade. So far, the group has visually surveyed nearly 10 million light curves and authored 69 peer-reviewed papers which mainly focus on exoplanets and discoveries involving multistellar systems. The preferred manual search-method carried out by the VSG has revealed its strength by detecting numerous objects which were overlooked or discarded by automated search programs, uncovering some of the most rare stars in our galaxy, and leading to several serendipitous discoveries of unprecedented astrophysical phenomena. The main purpose of the VSG is to assist in the exploration of our local universe, and we therefore advocate continued crowd-sourced examination of time-domain data sets, and invite other research teams to reach out in order to establish collaborating projects.
A first order superfluid-Mott insulator transition for a Bose–Hubbard model in an emergent lattice
Authors: Chen Yu
Published: July 2022

The combination of strong correlation and emergent lattice can be achieved when quantum gases are confined in a superradiant Fabry–Perot cavity. In addition to the discoveries of exotic phases, such as density wave ordered Mott insulator and superfluid, a surprising kink structure is found in the slope of the cavity strength as a function of the pumping strength. In this article, we show that the appearance of such a kink is a manifestation of a liquid–vapour-like transition between two superfluids with different densities. The slopes in the immediate neighborhood of the kink become divergent at the liquid–vapour critical points and display a critical scaling law with a critical exponent 1 in the quantum critical region.
Amplitude and phase modulation of optical feedback in a-cut Nd:YVO4 laser with a birefringent external cavity
Authors: Deng Shiwei , Zhang Zhiyuan , Shen Hua , Han Jianping , Liu Weixin
Published: July 2022

Considering only the self-mixing interference taking place, the modulation effect of optical feedback in a single polarization a-cut Nd:YVO4 laser is presented. The output intensity of the laser with anisotropic gain medium is modulated with a wave plate (WP) in the external cavity. The rotation orientation and phase retardation of the WP regularly determinate the amplitude and phase of laser intensity fringe, because the feedback light component at the same polarization direction as the output laser can interact with the light field in the cavity. The corresponding theoretical model is established and the windowed Fourier transform method is utilized to quantitatively explain this phenomenon. By introducing the amplitude and phase modulation coefficients, comparisons of experimental results with simulation analysis show good consistency.
Fluorine-plasma treated AlGaN/GaN high electronic mobility transistors under off-state overdrive stress
Authors: Zhao Dongyan , Wang Yubo , Chen Yanning , Shao Jin , Fu Zhen , Liu Fang , Cao Yanrong , Zhao Faqiang , Zhong Mingchen , Zhang Yasong , Ma Maodan , Lv Hanghang , Wang Zhiheng , Lv Ling , Zheng Xuefeng , Ma Xiaohua
Published: July 2022

Influences of off-state overdrive stress on the fluorine-plasma treated AlGaN/GaN high-electronic mobility transistors (HEMTs) are experimentally investigated. It is observed that the reverse leakage current between the gate and source decreases after the off-state stress, whereas the current between the gate and drain increases. By analyzing those changes of the reverse currents based on the Frenkel–Poole model, we realize that the ionization of fluorine ions occurs during the off-state stress. Furthermore, threshold voltage degradation is also observed after the off-state stress, but the degradations of AlGaN/GaN HEMTs treated with different F-plasma RF powers are different. By comparing the differences between those devices, we find that the F-ions incorporated in the GaN buffer layer play an important role in averting degradation. Lastly, suggestions to obtain a more stable fluorine-plasma treated AlGaN/GaN HEMT are put forwarded.
Demonstration and modeling of unipolar-carrier-conduction GaN Schottky-pn junction diode with low turn-on voltage
Authors: Guo Lijian , Xu Weizong , Wei Qi , Liu Xinghua , Li Tianyi , Zhou Dong , Ren Fangfang , Chen Dunjun , Zhang Rong , Zheng Youdou , Lu Hai
Published: July 2022

By introducing a thin p-type layer between the Schottky metal and n-GaN layer, this work presents a Schottky-pn junction diode (SPND) configuration for the GaN rectifier fabrication. Specific unipolar carrier conduction characteristic is demonstrated by the verification of temperature-dependent current–voltage (I–V) tests and electroluminescence spectra. Meanwhile, apparently advantageous forward conduction properties as compared to the pn diode fabricated on the same wafer have been achieved, featuring a lower turn-on voltage of 0.82 V. Together with the analysis model established in the GaN SPND for a wide-range designable turn-on voltage, this work provides an alternative method to the GaN rectifier strategies besides the traditional solution.
Mathematical model and PID control of a hydraulic motor using on/off solenoid valve
Authors: Aborobaa A N , Ghamry K A , Saleh A , Mabrouk M H
Published: July 2022

Hydraulic motors have a high power capacity that makes them commonly used in different applications. These applications require precise control of hydraulic motors’ position, velocity, and force. Digital hydraulic valves are commonly used in hydraulic power systems. The high-speed on/off valves (HSVs) are digital valves usually used in flow or pressure control where high dynamic performance is required to improve the control accuracy. This paper aims to present an accurate method of controlling a hydraulic motor using HSV and PID control. A mathematical model of the whole system is presented. This model allows predicting the system response and refining the control gains to reach the desired response. The model parameters are obtained by experimental measurement, or typical values are used. The model is implemented using MATLAB and SIMULINK. Then it is validated experimentally using some tests. The designed control method is implemented on the motor using NI myRIO as a controller, which is coded by LabVIEW software
Nonparametric modeling of magnetorheological damper based on nonlinear black-box technique
Authors: Abdelhamed M , Ata W G , Salem A M
Published: July 2022

Magnetorheological (MR) dampers are considered the most confident actuators for controlling vibratory systems due to their great advantages like high controllable dynamic range, low power consumption, and fail-safe devices. In this paper, a new nonparametric technique is utilised to model the MR-damper dynamics using Non-Linear Autoregressive Models with Exogenous Inputs (NLARX) approach. The proposed model is constructed based on the measured displacement, velocity, and damping forces of the commercial MR damper under various command voltages. The results of the nonparametric model show that such a model can expect the nonlinear dynamics of the MR damper under a wide range of different operating conditions. Furthermore, the proposed model output is compared with a well-known parametric model namely as Modified Bouc-Wen (MBW) model for additional validation. The comparison shows that the generated model can accurately track the measured damping force characteristics, work done by the damper, and the force-velocity hysteresis. It is also shown that the improvement of the damping force of the proposed model is better than the corresponding damping force of the parametric model which clearly shows the robustness of the generated model. The proposed model improves the root mean square (RMS) values of the experimental damping force by about 93.57% compared to an improvement of about 77.36% of the simulated damping force from the MBW model.
Thrust termination of solid rocket motor
Authors: Abdelraouf A M , Mahmoud O K , Al-Sanabawy M A
Published: July 2022

Rocket motors are engines that create the necessary thrust for the rocket motion. There are different types of rocket motors based on the propellant state, such as solid propellant rocket motors, liquid propellant rocket motors, and hybrid propellant rocket motors. One of the biggest disadvantages of solid propellant rocket motors, in comparison to liquid and hybrid propellant rocket motors, is that they are extremely difficult to extinguish, necessitating the use of specific devices. This paper reviews various ways for thrust termination such as fluid injection, rapid increase in throat area, and sudden opening of an additional port at the forward section of the motor, which increases the depressurization rate (dp/dt) required for extinguishing. The rate of depressurization varies depending on propellant components, combustion pressure, and exhaust pressure, and may be investigated using experimental approaches. The change in the critical area for a motor can be predicted by using MATLAB code to ensure the complete extinguishing by decreasing the pressure under the deflagrationlimit with high depressurization rate.
Experimental studies on thermophysical properties of ethylene glycol/water-based MgO nanofluids
Authors: Gamal M , Radwan M S , Elgizawy I G , Shedid M H
Published: July 2022

In the present study, the aim is to experimentally measure the isobaric specific heat, viscosity and thermal conductivity of different magnesium oxide (MgO) nanoparticles concentrations dispersed in ethylene glycol/ water mixture with ratio 50:50 vol% as a base fluid. The experiments were performed on 20 nm particle size of MgO nanoparticles suspended in base fluid with different volume fractions from 0.25 to 1% and temperature range from 40 to 120°C. The data results detected that the specific heat capacity of nanofluids reduces as the nanoparticles volume fraction increases but increases as the temperature rises. For all volume concentrations, the dynamic viscosity declines non-linearly with rising temperature. The increase in viscosity related to the base fluid is slightly recognized at low nanoparticles concentrations, while this change is more sensible at higher volume concentrations. Generally, MgO nanofluids showing higher viscosities than the base fluid used. The thermal conductivity of examined nanofluids increases uniformly with increasing the nanofluid sample temperature and nanoparticles volume concentration.
Comparative analysis of optimization strategies by software complex “Metaheuristic nature-inspired methods of global optimization”
Authors: Panteleev A V , Belyakov I A , Kolessa A A
Published: July 2022

This article discusses the comparative efficiency analysis results of algorithms for finding a global extrema for multivariable functions with parallelepiped constraints. Three metaheuristic nature-inspired optimization algorithms such as Grey Wolf Optimizer (GWO), Whale Optimization Algorithm (WOA) and Perch School Search (PSS) are presented. For algorithms comparative analysis the software complex was created, which allows visualizing a process of obtaining the approximate solution of standard generally accepted benchmark problems. The different examples of optimization algorithms results are given. Benchmark functions structure provides fairly estimating of compared optimization methods. The purpose of the paper is collecting and subsequent analysis of statistical results of algorithms accuracy and convergence pattern. Statistical data analysis makes it possible to choose the most suitable optimization method and to formulate valid recommendations to pick parameters for the most efficient solution of arbitrary objective function optimization problem.
Computer simulation of the physical neutralization of drones in a Smart City
Authors: Tovarnov M S , Bykov N V , Vlasova N S , Fedulov V A , Pozharsky A A
Published: July 2022

We present a simple computer simulation model for the interaction of automatic guns with unarmed drones. Each drone is represented as a rigid body that consists of several simple bodies such as parallelepipeds, ellipsoids, etc. The simplified spatial trajectory of the drone is constructed using third-order Bezier curves. A relatively large group of unconnected drones may be simulated in a computationally fast way using this method. Automatic guns are agents that are shooting at drones with a single of burst fire relative to the ideal aiming point. We performed a simulation of the flight of several drones against several automatic guns for different conditions. As a result of this simulation, the spatial distribution of the drone hit probabilities, the special distribution of the fraction of defeated drones depending on the number of guns, and the influence of urban obstacles on the fraction of drones defeated are presented.
The use of modern computer technologies in the study of the Geometric Modeling course
Authors: Zakharov A A , Zakharova Yu V
Published: July 2022

The paper describes the educational discipline “Geometric modeling”, which is suitable for students of applied mathematics. The course covers spline representations and transfinite interpolation methods for modeling the shape of geometric objects, the methods for performing Boolean operations between objects and methods for visualizing the objects. Screenshots of some graphic windows of the developed visualization programs for supporting the implementation of individual assignments in the course are shown. The programs have web interfaces that use the WebGL graphics API in a browser, independent of an operating system, and are also available for smartphones and tablets. They provide graphical output for curves and surfaces in three-dimensional space, user interfaces for entering the initial data and interaction with geometric objects. Students only need to write their own calculation code for the programs in the JavaScript programming language. The interactive tools enable students to get practical skills in working with splines and visually analyze the impact of the input data on the final geometry. The individual assignments and programs are specially focused to stimulate students’ interests. The paper is addressed to teachers of the geometric modeling for mathematicians and computer scientists. It seems to be interesting to those who develop software interfaces for geometric modeling algorithms.
Fractal feedback control for Elastic computing based on the Container–Component model
Authors: Semenov A S
Published: July 2022

One of the most significant characteristics of cloud computing is elasticity, which refers to the autoscaling control of resources based on the demands of the application or service. The problem of setting parameters of elastic autoscaling is not trivial and its solution depends on the control model. The Container-Component model that exploits the properties of fractals is investigated for this purpose. The fractal dimension is proposed to characterize the auto-scalability of distributed computing, independent of the implementation. The control of the fractal complexity by means of fractal feedback is considered.
Utilization of parallel computing for mathematical modeling of high-enthalpy flows
Authors: Gribinenko D V , Molchanov A M , Siluyanova M V , Yanyshev D S
Published: July 2022

The complexity of problems in gas dynamics is increasing from year to year, which makes sequential computational codes more and more inadequate and brings the importance of creating their parallel implementations. The problem of building the parallel implementations is not simple, especially in case of parallelization of the existing sequential codes. In this paper we present a method of simulation of high-enthalpy flows and describe the peculiarities of its parallel implementation utilizing PETSc library, which gives a wide variety of tools to simplify creation of parallel codes. The results for calculation of OREX reentry module as well as analysis of scalability of the parallel code implementation are given.
Impact of electronic excitation on the state-to-state vibrational-chemical CO kinetics
Authors: Yu Melnik M , Kustova E V
Published: July 2022

Dissociation of carbon monoxide in shock heated flows is studied with emphasis to the phenomenon of dissociation induction. Different kinetic schemes are implemented, both neglecting and including electronic excitation; various vibrational and electronic state-resolved models of dissociation rate coefficients are assessed. Vibrational-electronic relaxation coupled to dissociation behind the shock front is simulated in the frame of the state-to-state approach for several test cases with varying initial pressure, temperature, mixture composition and shock velocity. It is found that dissociation delay may appear regardless taking into account electronic excitation; the incubation time is mainly governed by mixture composition and initial pressure. Electronic excitation noticeably influences the overall dissociation rate. Recommendations for using specific dissociation models are given for different test cases.
Numerical study of the separation of a turbulent boundary in rocket engine nozzles with an optimized supersonic part
Authors: Shustov S A , Ivanov I E , Kryukov I A
Published: July 2022

At present, propulsion systems are being developed for flights of aerospace vehicles both in the Earth’s atmosphere and beyond. At the stage of the propulsion system design, it is necessary to be able to reliably determine the energy and thrust characteristics of rocket engines in regimes with flow separation in the nozzle for a wide range of nozzle pressure ratio (NPR) (1 ≤ m ≤ 30, m = ph
/pa
, p—pressure, indices h and a refer, respectively, to the parameters of the external environment and at the nozzle exit) characterizing the flow in nozzles and jets. In this case, the nozzle, as a rule, has a thrust optimized contour (TOC) supersonic part. In this regard, we present some results of a numerical study of flows with separation of the turbulent boundary layer in the TOC nozzles of main rocket engines in the above range of the NPR based on the Reynolds Averaged Navier–Stokes (RANS) system of equations.
Influence of magnetic field on the amplitude of flutter type oscillations of dielectric plate
Authors: Baghdasaryan G Y , Panteleev A V , Mikilyan M A
Published: July 2022

Stability problem of an isotropic dielectric plate streamlined by a supersonic gas flow is considered, when the plate is immersed in a longitudinal magnetic field. On the basis of the piston theory, the theory of magnetoelasticity and Maxwell equations, the appropriate formula for aerodynamic pressure is obtained, which can be used as an extension of piston formula. Formula is obtained to calculate the critical speed of flowing stream. On the basis of this formula the influence of magnetic field on the critical speed is studied. The system of non-linear differential equations is obtained, Galerkin method is used and the piston theory aerodynamic model for supersonic flow are employed to obtain the results.
Marine heatwaves in global sea surface temperature records since 1850
Authors: von Kietzell Arno , Schurer Andrew , Hegerl Gabriele C
Published: July 2022

The adverse impacts of marine heatwaves (MHWs) on marine ecosystems and human activities are well-documented, yet observational studies tend to largely rely on recent records. Long-term records of MHWs can put the recent increase in frequency and intensity of MHWs in the context of past variability. We used long-term monthly sea surface temperature (SST) data and night marine air temperatures to characterise past MHW activity. A persistent increase in the global extent of MHWs is demonstrated, beginning around 1970. The average annual MHW extent post-2010 is estimated to be increased at least four fold compared to that pre-1970. A strong correlation between spatial variance of recorded average monthly SSTs and the average inverse number of monthly observations implies both frequency and amplitude of MHWs is overestimated when the number of monthly observations is low. Nevertheless, many identified early MHWs appear genuine, such as a multi-month event in the North Atlantic in 1851–1852. MHWs are also affected by poorer sampling during the world wars. The most extensive MHW years globally coincide with El Niño years, and MHW extent in the North Atlantic is correlated with the Atlantic Multidecadal Oscillation.
Detecting inhomogeneous chiral condensation from the bosonic two-point function in the (1 + 1)-dimensional Gross–Neveu model in the mean-field approximation*
Authors: Koenigstein Adrian , Pannullo Laurin , Rechenberger Stefan , Steil Martin J , Winstel Marc
Published: July 2022

The phase diagram of the (1 + 1)-dimensional Gross–Neveu model is reanalyzed for (non-)zero chemical potential and (non-)zero temperature within the mean-field approximation. By investigating the momentum dependence of the bosonic two-point function, the well-known second-order phase transition from the

Z

2

symmetric phase to the so-called inhomogeneous phase is detected. In the latter phase the chiral condensate is periodically varying in space and translational invariance is broken. This work is a proof of concept study that confirms that it is possible to correctly localize second-order phase transition lines between phases without condensation and phases of spatially inhomogeneous condensation via a stability analysis of the homogeneous phase. To complement other works relying on this technique, the stability analysis is explained in detail and its limitations and successes are discussed in context of the Gross–Neveu model. Additionally, we present explicit results for the bosonic wave-function renormalization in the mean-field approximation, which is extracted analytically from the bosonic two-point function. We find regions—a so-called moat regime—where the wave function renormalization is negative accompanying the inhomogeneous phase as expected.
Magnetic ring chains with vertex coupling of a preferred orientation
Authors: Baradaran Marzieh , Exner Pavel , Lipovský Jiří
Published: July 2022

We discuss spectral properties of a periodic quantum graph consisting of an array of rings coupled either tightly or loosely through connecting links, assuming that the vertex coupling is manifestly non-invariant with respect to the time reversal and a homogeneous magnetic field perpendicular to the graph plane is present. It is shown that the vertex parity determines the spectral behavior at high energies and the Band–Berkolaiko universality holds whenever the edges are incommensurate. The magnetic field influences the probability that an energy belongs to the spectrum in the tight-chain case, and also it can turn some spectral bands into infinitely degenerate eigenvalues.
Mining and environmental problems of Dalnegorsk, Primorye territory, and ways to solve them
Authors: Filatova M Yu , Krupskaya L T , Kocharyan Yu G , Leonenko A V , Romashkina E A
Published: July 2022

Intensive development of deposits in the Primorsky Territory has led to the accumulation of a large amount of waste from the processing of mineral raw materials, which has a negative impact on the environment. The environmental situation is aggravated by the fact that tailings, where processing waste is stored, located near settlements (for example, Dalnegorsk). The protection of the ecosphere is an urgent geoecological problem. Therefore, the purpose of the study was to study the mining and environmental problems of ensuring the environmental safety of the technogenic system. The methodological basis of the study was the teaching of Academician V.I. Vernadsky about the biosphere and noosphere and the main provisions of B.P. Kolesnikov and A.V. Motorin, set out in the program and methodology for the study of technogenic ecosystems. The scientific novelty of the study lies in the complex geoecological assessment of environmental objects using mathematical methods. The patterns of migration of heavy metal compounds and arsenic from tailings to the components of the ecosphere are revealed. Methods for reducing the negative impact of mountain systems on the environment are substantiated using the capabilities of biological systems, the novelty of which is confirmed by patents of the Russian Federation.
Benzo(a)pyrene in the atmosphere and its carcinogenic risks to the health of the population of Irkutsk region cities
Authors: Belykh L I , Maksimova M A
Published: July 2022

We studied increase in cancer incidence in the population and the dynamics of the carcinogenic benzo(a)pyrene content in the atmospheric air of cities in the Irkutsk Region. Sources of air pollution boilers and household furnaces, aluminum production, motor vehicles, forest fires were considered. Individual and population carcinogenic risks of benzo(a)pyrene for the health of the population in industrial, agricultural and South Baikal cities were assessed. We also could establish the tendency of increasing risks and the dependence of the incidence of malignant neoplasms in the population on the content of benzo(a)pyrene in the atmosphere. The conclusion was made about the need to assess pollution sources, about the development of a monitoring system for benzo(a)pyrene and its analogs - polycyclic aromatic hydrocarbons - in the environment.
To the Subject of Waste Disposal at the Site of Human Settlements
Authors: Khairullina L B , Starikova G V , Mamaeva N L , Bulgakova E V , Mikhailova M N
Published: July 2022

The developed waste management system in our country requires a radical and fundamental change from the final deposition to environmental technologies - recycling and disposal. The investigations represented in the paper perform the dynamics of changes in the methods of municipal waste handling in the Tyumen region. Over the period from 2010 to 2020, the population of the region went up 1.4 times and on January 1, 2020 increased to 1 537 416 people (excluding autonomous districts), and in Tyumen - 816.6 thousand people. With the rise of the population, the amount of generated wastes is also growing and accounts to about 2 million tons/year. The creation of industries for the treatment, disposal and waste processing is an urgent task for the development of the domestic economy, which is regulated by the legislative and regulatory legal acts of the Russian Federation and its subjects. One of the main reasons for the weakness in the implementation of waste treatment and further disposal processes is the lack of an organized effective system for the separate waste collection, as well as their subsequent treatment, disposal and waste processing on an industrial scale.
Prospects for the development of renewable energy for the energy supply of buildings in Russia
Authors: Alekhin V N , Sharovarova E P
Published: July 2022

The article considers the significance of the problem of renewable energy and energy saving technology development. The potential of solar and geothermal energy in the Russian Federation, the feasibility of using stable and inexhaustible renewable energy sources for implementation in buildings and structures are discussed. Construction, operation of buildings and structures consume up to half of all generated energy in the world. The efficiency of enclosing structures significantly affects the energy saving of buildings and generates up to 30% of heat losses. Using renewable energy technology in construction is effective with enclosing structures with high thermal insulation characteristics. Territories of the Russian Federation with decentralized energy supply, characterized by low consumer power, lack of access to power grids, lack of fuel, harsh climatic conditions, and low population density, have a high potential for the implementation of renewable energy sources (RES) into the buildings.
The effect of mineral fertilizers on reproduction of soil saprophytic bacteria
Authors: Sidorenko M L
Published: July 2022

The study of vital activity regulation of soil microorganisms is one of the general problems of soil microbiology. One of the factors influencing the existence and reproduction of bacteria in terrestrial ecosystems are fertilizers introduced into the soil. The effect of mineral fertilizers on the reproduction of bacterial complexes in soils of diverse types at different temperatures (4 ° C and 20 ° C) was studied. Mineral fertilizing promotes the active reproduction of saprophytic bacteria in calcaric cambisol (CCS) and distric cambisol soils (DCS). The variants with fertilizers can be arranged according to their effect on the reproduction of saprophytic bacteria in following order, regardless of the soil type: soil with nitric fertilizer > soil with phosphoric fertilizers > soil with potash fertilizer. Introduction of nitric or phosphoric fertilizers at 20 °C was more successful in CCS. It was found that application of mineral fertilizers positively affects the conservation and reproduction of bacteria in soils of diverse types. Prolonged application of mineral fertilizers reveals a positive effect on bacterial complexes, regardless of the soil type.
Applying best available techniques and best environmental practices to preserve ecosystem services
Authors: Morokishko V , Volosatova A , Ilina V , Vertyshev S , Malkov A
Published: July 2022

The study offers an analysis of two concepts used for reducing negative environmental impact: best available techniques and best environmental practices. The concept of best available techniques has been widely used for a long time and has proven to be an effective tool for implementing various regulatory mechanisms. Best environmental practices, on the other hand, have not been known for very long and their application is not yet widespread. Best environmental practices are only applied voluntarily; this fact distinguishes them from best available techniques which in most cases are regulated by legal acts. However, it would be a mistake to assume that best environmental practices are not particularly important within the framework of environmental regulation. On the contrary, their role is increasing, because any additional tools can not only help modernise industrial manufacturing processes, but also improve the image of the enterprise. The relevance of the study stems from the need to find solutions to preserve and restore ecosystem services. The concepts in question can serve as a framework for preventing further degradation of ecosystem services. The study has reviewed normative legal acts of the Russian Federation along with papers and monographs by researchers or experts in the field.
Using the hulls of industrial hemp in urban surface waste water treatment
Authors: Samodolova O , Ulrikh D
Published: July 2022

Environmental pollution is one of the most serious problems that cities around the world are facing. Despite strict governmental policies in environmental laws and attempts by various countries to convert to closed-loop economies, the water, air, and soil pollution remains a pressing issue. One possible solution to this problem is to use phytogenic waste as a raw material for the production of sorbents to treat waste water. Recycling phytogenic waste in this manner solves several problems simultaneously: disposal of several tons of industrial and agricultural waste; increasing the effectiveness of water treatment; reducing the costs of water treatment; creation and use of an environmentally-friendly material. The article presents a complex study on the possibilities of using phyto enic waste from hemp production (hemp hulls) as a sorbent for the treatment of surface waste water in urban territories. The current state of the hemp industry and the prospects for its development are examined. A microanalysis of the composition of hemp hulls has been conducted on a JEOL JSM-6460 LV electron scanning microscope. The sorption capacity of hemp hulls at varying conditions has been examined.