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Representation of three-dimensional mass distribution of the Earth's interior by biorthogonal series and its use for studying internal structure of the planet

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Geodesy and Geodynamics 2024年第3期15卷 264-275页

作者： Mykhailo Fys Mariana Yurkiv Andrii Brydun Andrii Sohor Department of Cartography and Geospatial Modelling Lviv Polytechnic National UniversityLviv 79013Ukraine

This paper utilizes the mathematical concept of approximation within an ellipsoid from a single viewpoint to present the spatial mass distribution function of the Earth's interior and its internal *** primary focus lies in constructing the volume distribution of masses in the planet's interior, with the expansion coefficients being linear combinations of the Stokes constants. Several possible approaches are suggested for determining accurately these coefficients employing three-dimensional(biorthogonal)polynomials. By expressing the mass distribution function of the Earth's interior and its internal potential as a series, an algorithm is introduced for the calculation of gravitational energy. It allows us to estimate fluctuations in gravitational energy. The implementation of this algorithm offers the means of establishing the extent to which the Earth deviates from a state of hydrostatic equilibrium as a celestial *** to the aforementioned method, calculations have been conducted to validate its effectiveness and reliability. This example is given as an illustration of a given method for studying the internal structure of planets.

关键词： Mass distribution function Potential Stokes constants Biorthogonal polynomials

Beneficial use of mussel shell as a bioadditive for TPU green composites by the valorization of an aqueous waste

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Waste Disposal and Sustainable Energy 2024年第1期6卷 123-137页

作者： SedefŞişmanoğlu Yasin Kanbur Carmen-Mihaela Popescu Diana Kindzera Ümit Tayfun Department of Chemistry Karabuk University78050KarabukTurkey Petru Poni Institute of Macromolecular Chemistry of the Romanian Academy 700487IasiRomania Department of Chemical Engineering Lviv Polytechnic National UniversityLviv79013Ukraine Department of Basic Sciences Bartin University74110BartinTurkey

Scientific studies have focused on environmentally friendly solutions as effective as the reuse of crop products owing to plastic-waste problems in recent *** issue is the main driving force for upcoming academic research attempts in waste valorization-related ***,we integrated an aqua-waste,mussel shell(MS),as a bioadditive form into green thermoplastic polyurethane(TPU)green *** of the MS surface was performed to achieve strong adhesion between composite *** surface functionalities of MS powders were evaluated via infrared spectroscopy and scanning electron microscopy(SEM)*** samples were prepared by melt-compounding followed by injection molding *** was confirmed by morphological analysis that relatively better adhesion between the phases was achieved for composites involving surface-modified MS compared to unmodified *** strength and Young’s modulus of surface-modified MS-filled composites were found to be higher than those of unmodified MS,whereas the elongation at break shifted to lower values with MS *** shore hardness of TPU was remarkably improved after being incorporated with silane-treated MS(AS-MS).Stearic acid-treated MS(ST-MS)additions resulted in an enhancement in the thermal stability of the ***-mechanical analysis showed that the storage moduli of composites were higher than those of unfilled ***-MS additions led to an increase in the characteristic glass transition temperature of *** flow index(MFI)of neat TPU was highly improved after MS loading regardless of modification *** to the wear test,surface modification of MS displayed a positive effect on the wear resistance of *** the water absorption data of the composites were evaluated,the TPU/AS-MS composite yielded the lowest water *** silane layer on MS inclusion promoted water repellency of composites due to the hydrophobicity of *** results of the biodegradation

关键词： Aqua-waste Polyurethane Mussel shell Green composites Sustainability Waste valorization

Thermogravimetric,kinetic study and gas emissions analysis of the thermal decomposition of waste-derived fuels

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Journal of Environmental Sciences 2024年第3期137卷 155-171页

作者： Vadim V.Dorokhov Galina S.Nyashina Pavel A.Strizhak Heat and Mass Transfer Laboratory National Research Tomsk Polytechnic University30 Lenin AvenueTomsk 634050Russia

A wide range of wastes can potentially be used to generate thermal and electrical *** co-combustion of several types of waste as part of water-containing waste-derived fuels is a promising method for their *** this research,we use thermogravimetric analysis and differential scanning calorimetry to study the thermal behavior and kinetics of coal slime,biomass,waste oils,and blends on their *** also analyze the concentrations of gaseous *** results show that biomass,oils,and coal slime significantly affect each other in the course of their co-combustion when added to slurry *** preparation of coal-water slurry based on slime and water reduced the ignition and burnout temperature by up to 16%.Adding biomass and waste oils additionally stimulated the slurry ignition and burnout,which occurred at lower *** to dry coal slime,threshold ignition temperatures and burnout temperatures decreased by 6%–9%and 17%–25%,***,the use of biomass and waste oils as part of slurries inhibited NOхand SO_(2)emission by 2.75 *** to the kinetic analysis,added biomass and waste turbine oil provide a 28%–51%reduction in the activation energy as compared to a coal-water slurry without additives.

关键词： Coal-water slurry Water-containing composite fuels Combustion Emission Kinetic TGA-DSC

Phase Transition in a Dense Swarm of Self-Propelled Bots

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Fluid Dynamics & Materials Processing 2024年第8期20卷 1785-1798页

作者： Dmitry Bratsun Kirill Kostarev Applied Physics Department Perm National Research Polytechnic UniversityPerm614990Russia

Swarms of self-organizing bots are becoming important elements in various technical systems,which include the control of bacterial cyborgs in biomedical applications,technologies for creating new metamaterials with internal structure,self-assembly processes of complex supramolecular structures in disordered media,*** this work,we theoretically study the effect of sudden fluidization of a dense group of bots,each of which is a source of heat and follows a simple algorithm to move in the direction of the gradient of the global temperature *** show that,under certain conditions,an aggregate of self-propelled bots can fluidize,which leads to a second-order phase *** bots’program,which forces them to search for the temperature field maximum,acts as an effective buoyancy *** a consequence,one can observe a sudden macroscopic circulation of bots from the edge of the group to its center and back again,which resembles classical Rayleigh-Benard thermal *** the continuum approximation,we have developed a mathematical model of the phenomenon,which reduces to the equation of a self-gravitating porous disk saturated with an incompressible fluid that generates *** derive governing equations in the Darcy-Boussinesq approximation and formulate a nonlinear boundary value *** exact solution to the linearized problem for infinitesimal perturbations of the base state is obtained,and the critical values of the control parameter for the onset of the bot circulation are *** we apply weakly nonlinear analysis using the method of multiple time *** found that as the number of bots increases,the swarm exhibits increasingly complex patterns of circulation.

关键词： Active matter collective behavior self-organization convection

Modeling the Physical Parameters of Solenoids for MEMS Applications

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Journal of Applied Mathematics and Physics 2024年第5期12卷 1819-1834页

作者： Mykhaylo Andriychuk Bohdan Karkulovskyi Yarko Kuleshnyk Department of Computer Design System Lviv Polytechnic National University Lviv Ukraine Department of Numerical Methods of Mathematical Physics Pidstryhach Institute for Applied Problems of Mechanics and Mathematics NASU Lviv Ukraine

The paper is devoted to study of the electrical parameters of the motion parts of the MEMS such as solenoids. The analytical background is given in order to describe the influence of the electrical field components on the forces, which are result of interaction of the electromagnetic (EM) field components with the parts of motion devices of MEMS. The given analytical formulas open the ability to calculate the self-inductance of the microsolenoids of the different kind, as well as the stored energy of such motion devices, that could be used for the modeling and optimization of parameters of running devices of MEMS such as actuators, sensors etc.

关键词： EM Description Motion Microdevice Microsolenoid Stored Energy Computational Data

Influence of Methane-Hydrogen Mixture Characteristics on Compressor Vibrations

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Fluid Dynamics & Materials Processing 2024年第5期20卷 1031-1043页

作者： Vladimir Ya.Modorskii Ivan E.Cherepanov High Performance Computing Center Perm National Research Polytechnic UniversityPerm614990Russia

A transition to clean hydrogen energy will not be possible until the issues related to its production, transportation,storage, etc., are adequately resolved. Currently, however, it is possible to use methane-hydrogen *** gas can be transported using a pipeline system with the required pressure being maintained by gascompression stations. This method, however, is affected by some problems too. Compressors emergency stopscan be induced by vibrations because in some cases, mechanical methods are not able to reduce the vibrationamplitude. As an example, it is known that a gas-dynamic flow effect in labyrinth seals can lead to increasedvibrations. This paper presents the numerical simulation of rotor oscillations taking into account a gas-dynamicload. The influence of a transported mixture on the oscillatory process is investigated. Mixtures consisting ofmethane and hydrogen in various proportions and an air mixture are considered. The results are discussed forvarious operating pressures and include the rotor motion trajectories and oscillation frequency spectra obtainednumerically. It is shown that the gas mixture composition has a significant effect on the oscillations and theiroccurrence. Hydrogen as a working fluid reduces the vibration amplitude. Operating a compressor with hydrogenleads to a decrease in the resonant frequency, bringing it closer to the operating one. However, the operatingpressure at which maximum oscillations are observed depends slightly on the gas mixture composition.

关键词： Seal stabilities vibration FSI CFD multiphase flows hydrogen

Insights into sensitizing and eliciting capacity of gastric and gastrointestinal digestion products of shrimp(Penaeus vannamei)proteins in BALB/c mice

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Food Science and Human Wellness 2024年第1期13卷 339-348页

作者： Yao Liu Songyi Lin Kexin Liu Shan Wang Wang Li Na Sun national Engineering Research Center of Seafood School of Food Science and TechnologyDalian Polytechnic UniversityDalian 116034China Collaborative Innovation Center of Seafood Deep Processing Dalian Polytechnic UniversityDalian 116034China

Shrimp(Penaeus vannamei)proteins have been shown an allergenic potential;however,little information is available on the sensitizing and eliciting capacity of shrimp protein digestion *** this study,a BALB/c mice model was used to explore the allergenicity of shrimp protein sample(SPS)and their gastric and gastrointestinal digestion products(GDS/GIDS).As compared with the SPS groups,the GDS/GIDS groups caused lower specific immunoglobulins(Ig E/Ig G1)levels(P<0.05),but higher than the control groups,indicating that the digestion products sensitized the ***,spleen index,mouse mast cell protease-1(m MCP-1)concentration and proportion of degranulated mast cells were significantly reduced in the GDS/GIDS groups(P<0.05);simultaneously,allergic symptoms,vascular permeability and histopathological changes of tissues were ***,the allergenicity of digestion products cannot be eliminated and still cause systemic allergic reactions in *** study showed that the digestion products of shrimp still had high sensitizing and eliciting capacity.

关键词： Penaeus vannamei Allergenicity Digestion BALB/c mice model

Numerical Analysis of Permeability of Functionally Graded Scaffolds

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Fluid Dynamics & Materials Processing 2024年第7期20卷 1463-1479页

作者： Dmitry Bratsun Natalia Elenskaya Ramil Siraev Mikhail Tashkinov Laboratory of Mechanics of Biocompatible Materials and Devices Perm National Research Polytechnic UniversityPerm614990Russia

In this work,we numerically study the hydrodynamic permeability of new-generation artificial porous materials used as scaffolds for cell growth in a perfusion *** consider two popular solid matrix designs based on triply periodic minimal surfaces,the Schwarz P(primitive)and D(diamond)surfaces,which enable the creation of materials with controlled porosity *** latter property is crucial for regulating the shear stress field in the pores of the scaffold,which makes it possible to control the intensity of cell *** permeability of functionally graded materials is studied within the framework of both a microscopic approach based on the Navier-Stokes equation and an averaged description of the liquid filtration through a porous medium based on the equations of the Darcy or Forchheimer *** calculate the permeability coefficients for both types of solid matrices formed by Schwarz surfaces,study their properties concerning forward and reverse fluid flows,and determine the ranges of Reynolds number for which the description within the Darcy or Forchheimer model is ***,we obtain a shear stress field that varies along the sample,demonstrating the ability to tune spatially the rate of tissue growth.

关键词： Porous media ﬁltration models scaffolds functionally graded materials

Selective nano-buckling improves the performance of graphene logic transistors

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national Science Review 2024年第2期11卷 95-96页

作者： Tong Yang Ming Yang Department of Applied Physics The Hong Kong Polytechnic University Research Centre for Nanoscience and Nanotechnology The Hong Kong Polytechnic University

The massive integration of silicon-based transistors into modern electronic devices greatly increases power consumption and heat generation/dissipation[1]. In this concern, transistors based on atomically-thin graphene that exhibit high electric and thermoelectric conductivities with negligible contact resistance,

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