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Radiation force and torque on a two-dimensional circular cross-section of a non-viscous eccentric layered compressible cylinder in acoustical standing waves

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Chinese Physics B 2021年第2期30卷 355-366页

作者： F g Mitri Santa Fe NM 87508USA

The purpose of this study is to develop an analytical formalism and derive series expansions for the time-averaged force and torque exerted on a compound coated compressible liquid-like cylinder,insonified by acoustic standing waves having an arbitrary angle of incidence in the polar(transverse)*** host medium of wave propagation and the eccentric liquid-like cylinder are *** computations illustrate the theoretical analysis with particular emphases on the eccentricity of the cylinder,the angle of incidence and the dimensionless size parameters of the inner and coating cylindrical fluid *** method to derive the acoustical scattering,and radiation force and torque components conjointly uses modal matching with the addition theorem,which adequately account for the multiple wave interaction effects between the layer and core fluid *** results demonstrate that longitudinal and lateral radiation force components ***,an axial radiation torque component is quantified and computed for the non-absorptive compound cylinder,arising from geometrical asymmetry considerations as the eccentricity *** computational results reveal the emergence of neutral,positive,and negative radiation force and torque depending on the size parameter of the cylinder,the eccentricity,and the angle of incidence of the insonifying ***,based on the law of energy conservation applied to scattering,numerical verification is accomplished by computing the extinction/scattering energy *** results may find some related applications in fluid dynamics,particle trapping,mixing and manipulation using acoustical standing waves.

关键词： radiation force radiation torque liquid compound cylinder multiple scattering acoustical standing waves

Acoustic radiation force and torque on a lossless eccentric layered fluid cylinder

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Chinese Physics B 2020年第11期29卷 140-145页

作者： F g Mitri Santa Fe NM 87508USA

Exact analytical equations and computations for the longitudinal and transverse acoustic radiation force and axial torque components for a lossless eccentric liquid cylinder submerged in a nonviscous fluid and insonified by plane waves progressive waves(of arbitrary incidence in the polar plane)are established and computed *** modal matching method and the translational addition theorem in cylindrical coordinates are used to derive exact mathematical expressions applicable to any inner and outer cylinder sizes without any approximations,and taking into account the interaction effects between the waves propagating in the layer and those scattered from the cylindrical *** results show that longitudinal and transverse radiation force components arise,in addition to the emergence of an axial radiation torque component acting on the non-absorptive compound cylinder due to geometrical asymmetry as the eccentricity *** computations demonstrate that the axial torque component,which arises due to a geometrical asymmetry,can be positive(causing counterclockwise rotation in the polar plane),negative(clockwise rotation)or neutral(rotation cancellation)depending on the size parameter of the cylinder and the amount of ***,verification and validation of the results have been accomplished from the standpoint of energy conservation law applied to scattering,and based on the reciprocity theorem.

关键词： acoustic radiation force acoustic radiation torque non-viscous liquid eccentric cylinder

New method for rekindling the explosive waves in Maxwellian space plasmas

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Plasma Science and Technology 2020年第12期22卷 48-58页

作者： g C DAS Kalikadas Road Byelane HazraparaCoochbehar-736101West BengalIndia

Our interest is to study the nonlinear wave phenomena in complex plasma constituents with Maxwellian electrons and ions. The main aim is to use a new method known as the(g′/g)method to exhibit the effects of dust charge fluctuations on the evolution of nonlinear waves. The coherent features of the shock and solitary waves along with the generation of high-energy waves have been amplified through the solution of the Korteweg–de Vries–Burgers equation,and the different natures of the waves were found successfully. Results are discussed graphically with the thoughtful choice of typical plasma parameters from different space plasma environments, exactly those found in cosmic dusty plasmas laden in ionospheric auroral region,radial spokes of Saturn's rings, planetary nebulae and solar F-corona region. All conclusions are in good accordance with the actual occurrences and could be of interest to further investigations of space. Moreover, the applicability of the present method is hoped to be a great enhancement by its use as ingenious mechanism used to evaluate the soliton dynamics and Burgers shock waves.

关键词： Maxwellian complex plasma nonlinear waves soliton and shock propagation (g′/g)method space plasmas

Nonlinear vibration analysis of laminated composite Mindlin micro/nano-plates resting on orthotropic Pasternak medium using DQM

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Applied Mathematics and Mechanics(English Edition) 2015年第8期36卷 1033-1044页

作者： A.g.ARANI g.S.JAFARI Faculty of Mechanical Engineering University of Kashan Institute of Nanoscience & Nanotechnology University of Kashan

The nonlocal nonlinear vibration analysis of embedded laminated micro- plates resting on an elastic matrix as an orthotropic Pasternak medium is investigated. The small size effects of micro/nano-plate are considered based on the Eringen nonlocal theory. Based on the orthotropic Mindlin plate theory along with the von Kármán geo- metric nonlinearity and Hamilton＇s principle, the governing equations are derived. The differential quadrature method （DQM） is applied for obtaining the nonlinear frequency of system. The effects of different parameters such as nonlocal parameters, elastic me- dia, aspect ratios, and boundary conditions are considered on the nonlinear vibration of the micro-plate. Results show that considering elastic medium increases the nonlinear frequency of system. F^lrthermore, the effect of boundary conditions becomes lower at higher nonlocal parameters.

关键词： nonlinear vibration laminated micro-plate orthotropic Pasternak medium,differential quadrature method

Quantum statistical properties of photon-added spin coherent states

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Chinese Physics B 2017年第11期26卷 206-209页

作者： g Honarasa Department of Physics Shiraz University of Technology

The photon-added spin coherent state as a new kind of coherent state has been defined by iterated actions of the proper raising operator on the ordinary spin coherent state. In this paper, the quantum statistical properties of photon-added spin coherent states such as photon number distribution, second-order correlation function and Wigner function are studied. It is found that the Wigner function shows the negativity in some regions and the second-order correlation function is less than unity. Therefore, the photon-added spin coherent state is a nonclassical state.

关键词： photon-added spin coherent states photon number distribution Wigner function

Dielectric behavior of Cu-Zn ferrites with Si additive

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Chinese Physics B 2014年第5期23卷 553-555页

作者： Uzma g Department of Physics University of Wah

Since ferrites are highly sensitive to the additives present in or added to them, extensive work, to improve the properties of basic ferrites, has been carded out on these aspects. The present paper reports the effects of composition, frequency, and temperature on the dielectric behavior of a series of CuxZn1-xFe2O4 ferdte samples prepared by the usual ceramic technique. In order to improve the properties of the samples, low cost Fe2O3 having 0.5 wt.% Si as an additive is selected to introduce into the system. The dielectric constant increases by increasing the Cu content, as the electron exchange of Cu^2＋〈=〉 Cu^＋ is responsible for the conduction and the polarization. However, the addition of Si could decrease the dielectric constant as it suppresses the ceramic grain growth and promotes the quality factor at higher frequencies. Dielectric constant ε′ and loss tangent tan δ of the mixed Cu-Zn ferrite decrease with increasing frequency, attributed to the Maxwell-Wagner polarization, which increases as the temperature increases.

关键词： Cu-Zn ferrite dielectric behavior Si additive

Experimental Investigation on the Performance of Armour grade Q&T Steel Joints Fabricated by Flux Cored Arc Welding with Low Hydrogen Ferritic Consumables

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Journal of Materials Science & Technology 2009年第5期25卷 583-591页

作者： g.Magudeeswaran V.Balasubramanian g.Madhusudhan Reddy g.gopalakrishnan Metal Joining Research Center(MJRC) Sri Ramakrishna Engineering CollegeN.G.G.O Colony-Post Centre for Materials Joining&Research(CEMAJOR) Department of Manufacturing EngineeringAnnamalai University Scientist-F Metal Joining SectionDefence Metallurgical Research Laboratory(DMRL)Kanchanbagh(P.O)

Quenched and Tempered （Q＆T） steels are widely used in the construction of military vehicles due to its high strength to weight ratio and high hardness. These steels are prone to hydrogen induced cracking （HIC） and softening in the heat affected zone （HAZ） after welding. The use of austenitic stainless steel （ASS） consumables to weld the above steel was the only available remedy to avoid HIC because of higher solubility for hydrogen in austenitic phase. Recent studies revealed that low hydrogen ferritic （LHF） steel consumables can also be used to weld Q＆T steels, which can give very low hydrogen levels in the weld deposits and required resistance against cold cracking. Hence, in this investigation an attempt has been made to study the performance of armour grade Q＆T steel joints fabricated by flux cored arc welding with LHF steel consumables. Two different consumables namely （i） austenitic stainless steel and （ii） low hydrogen ferritic steel have been used to fabricate the joints by flux cored arc welding （FCAW） process. The joints fabricated by LHF consumable exhibited superior transverse tensile properties due to the presence of ferrite microstructure in weld metal. The joints fabricated by ASS consumable showed higher impact toughness due to the presence of austenitic phase in weld metal microstructure. The HAZ softening in coarse grain heat affected zone （CgHAZ） is less in the joints fabricated using LHF consumable due to the lower heat input involved during fabrication compared to the joints fabricated using ASS consumables.

关键词： Quenched and tempered steel Flux cored arc welding process Low hydrogen ferritic steel Tensile properties

ZnO/CdS nanocomposites:Synthesis,structure and morphology

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Particuology 2012年第6期10卷 722-728页

作者： g.Murugadoss Department of Physics Annamalai UniversityAnnamalai Nagar 608 002TamilnaduIndia

Uncoated ZnO, CdS and ZnO/CdS nanocomposites were successtully synthestzecl cnemJcally in atmo-spheric air using a water-ethanol matrix. The as-obtained samples were characterized by X-ray diffraction, transmission electron microscopy （TEM）, UV-vis and photoluminescence （PL） spectropho-tometry. The luminescence measurements ofZnO/CdS nanocomposites showed narrow and enhanced PL emission in the blue region, PL quenching was observed in ZnO/CdS nanocomposites by increasing Cd and S concentrations.

关键词： NanocompositesSurface defectQuantum confinement TEM Photoluminescence

Some studies on transient behaviours of sheath formation in dusty plasma with the effect of adiabatically heated electrons and ions

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Plasma Science and Technology 2017年第9期19卷 35-40页

作者： g C DAS gyan Darshan Academy VIP RoadGuwahati-781022India

Based on quasipotential analysis, a plasma sheath is studied through the derivation of the Sagdeev potential equation in dusty plasma coexisting with adiabatically heated electrons and ions. Salient features as to the existence of sheaths are shown by solving the Sagdeev potential equation through the Runge–Kutta method, with appropriate consideration of adiabatically heated electrons and ions in the dynamical system. It has been shown that adiabatic heating of plasma sets a limit to the critical dust speed depending on the densities and Mach number, and it is believed that its role is very important to the sheath. One present problem is the contraction of the sheath region whereby dust grains levitated into the sheath lead to a crystallization similar to the formation of nebulons and are compressed to a larger chunk of the dust cloud by shrinking of the sheath. Our overall observations advance knowledge of sheath formation and are expected to be of interest in astroplasmas.

关键词： sheath heated dynamical Kutta Runge derivation shrinking coexisting grains compressed