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Vibration suppression of magnetostrictive laminated beams resting on viscoelastic foundation

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Applied mathematics and mechanics(English Edition) 2020年第8期41卷 1269-1286页

作者： A.m.ZENKOUR H.d.EL-SHAHRANY department of mathematics Faculty of ScienceKing Abdulaziz UniversityJeddah 21589Saudi Arabia department of mathematics Faculty of ScienceKafrelsheikh UniversityKafrelsheikh 33516Egypt department of mathematics Faculty of ScienceBisha UniversityBisha 61922Saudi Arabia

The vibration suppression analysis of a simply-supported laminated composite beam with magnetostrictive layers resting on visco-Pasternak’s foundation is *** constant gain distributed controller of the velocity feedback is utilized for the purpose of vibration *** formulation of displacement field is proposed according to Euler-Bernoulli’s classical beam theory(ECBT),Timoshenko’s first-order beam theory(TFBT),Reddy’s third-order shear deformation beam theory,and the simple sinusoidal shear deformation beam ***’s principle is utilized to give the equations of motion and then to describe the vibration of the current *** on Navier’s approach,the solution of the dynamic system is *** effects of the material properties,the modes,the thickness ratios,the lamination schemes,the magnitudes of the feedback coefficient,the position of magnetostrictive layers at the structure,and the foundation modules are extensively studied and discussed.

关键词： vibration suppression laminated composite beam magnetostrictive material visco-Pasternak’s foundation

Enhancement of coercivity,permeability,and dielectric properties of Co_(0.2)Zn_(0.3)ni_(0.5)Eu_(x)Fe_(2-x)O_(4) ferrites for memory and high frequency devices

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Journal of Rare Earths 2024年第6期42卷 1128-1135,I0005页

作者： I.Sardar m.d.Hossain m.S.Sikder m.N.I.Khan m.R.Rahman Physics discipline Khulna UniversityKhulna9208Bangladesh department of Physics Khulna University of Engineering&TechnologyKhulna9203Bangladesh department ofComputer Science and Engineering Northern University of Business&Technology KhulnaKhulna9100Bangladesh material Science division Atomic Energy CentreDhaka1000Bangladesh

Spinel cubic ferrites have huge applications in me mory and high frequency *** the improvement of these modern devices,the magnetic coercivity,permeability,and dielectric properties of a ferrite are the important *** article focuses on improving the magnetic coercivity,magnetic permeability,and dielectric properties of Co_(0.2)Zn_(0.3)ni_(0.5)Eu_(x)Fe_(2-x)O_(4) ferrites,where x=0.00,0.06,and *** X-ray diffraction(XRd),Fourier transform infrared spectroscopy(FTIR),field emission scanning electron microscopy(FESEm),energy dispersive X-ray(EdX),vibrating sample magnetometer(VSm),and an impedance analyzer were used to characterize the structural,magnetic,and dielectric properties of the *** XRd patterns indicate the formation of spinel cubic structure of the samples with a secondary peak(EuFeO_(3))for Eu doped *** densities and porosities of the samples follow an inverse trend,where the doped samples’lattice parameters are increased with the increment of rare earth Eu *** FTIR analysis also proves the spinel cubic phase of the *** average grain size of the ferrites is obtained via FESEm images,and it is increased from 121 to 198 *** analysis confirms that doping of the Eu content also changes other hysteresis loop properties of Co_(0.2)Zn_(0.3)ni_(0.5)Eu_(x)Fe_(2-x)O_(4) ***,the coercivity of the Eu doped samples is greater than that of the mother alloy(x=0.00).The EdX study shows that there is no impurity contamination in the *** permeability and dielectric measurements show an improved quality factor of the Eu-doped samples with low magnetic and dielectric *** dependent resistivity and impedance analysis also show the improved *** the observed properties of the samples,all the investigated ferrites might be strong candidates for potential applications in memory devices,magnetic sensors,and high frequency applications.

关键词： Ferrites Raree arths Coercivity Permeability EdX Resistivity

Comparative analysis of different static mixers performance by CFd technique:An innovative mixer

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Chinese Journal of Chemical Engineering 2020年第3期28卷 672-684页

作者： m.m.Haddadi S.H.Hosseini d.Rashtchian martin Olazar Chemical and Petroleum Engineering department Sharif University of TechnologyTehranIran department of Chemical Engineering.Ilam University llam 69315-516Iran department of Chemical Engineering University of the Basque Country(UPV/EHU)Sarriena s/nLeioaSpain

The flow and mixing behavior of two miscible liquids has been studied in an innovative static mixer by using CFd,with Reynolds numbers ranging from 20 to *** performance of the new mixer is compared with those of Kenics,SmX,and Komax static *** pressure drop ratio(Z-factor),coefficient of variation(CoV),and extensional efficiency(α)features have been used to evaluate power consumption,distributive mixing,and dispersive mixing performances,respectively,in all *** model is firstly validated based on experimental data measured for the pressure drop ratio and the coefficient of *** results are consistent with measured data and those obtained by available correlations in the *** new mixer shows a superior mixing performance compared to the other mixers.

关键词： CFd New static mixer Coefficient of variation Pressure drop ratio

Tuning red-green-white up-conversion color in nano NaYF_4:Er/Yb phosphor

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Journal of Rare Earths 2011年第12期29卷 1152-1156页

作者： A.Bednarkiewicz d.Wawrzynczyk m.Nyk m.Samo Institute of Low Temperature and Structure Research Polish Academy of Sciences(PAN) Wrocaw 50-422 Poland 2.Institute of Physical and Theoretical Chemistry Department of ChemistryWrocaw University of Technology

The possibility of ttming between red, green and broadband white color of up-conversion was demonstrated in thermally 450 ℃ treated Yb/Er co-doped nano NaYF4 phosphor. The color variability was studied by means of power dependence of luminescence, which exhibited unusual behavior. Large hysteresis, as well as discrepancy from a power law indicated the important role the increased heating played during the up-conversion in nano-sized materials.

关键词： lanthanides up-conversion white up-conversion emission nanphosphors rare earths

Theoretical Studies on Interaction Between methanol and Functionalized Single-Walled Carbon Nanotubes

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Communications in Theoretical Physics 2011年第2期55卷 365-370页

作者： m.d.Ganji m.Goodarzi m.Nashtahosseini A.mommadi-nejad department of Chemistry Islamic Azad University Ghaemshahr Branch Mazandaran Iran department of Chemistry Islamic Azad University Arak Branch Young Researchs Club Iran department of Computer Engineering Olom Fonon University of Mazandaran Babol Iran

We study the adsorption of a methanol molecule on single-walled carbon nanotubes （SWCNTs） with various diameters and chiral angles by using the density functional theory based calculations. We find that methanol prefers to be adsorbed physically on the exterior surface of chiral nanotubes in comparison to the armchair and zigzag tubes with binding energy of about -2.76 kcal/mol, which is consistent with recent experimental and theoretical investigation results. We further consider the adsorption of methanol on the exterior surface and edge site of functionalized SWCNTs. The obtained results indicate that the binding energy of methanol is significantly increased for adsorption on the sidewall of functionalized nanotubes. It is also found that the adsorption of methanol at the edge site of both functionalized and pristine SWCNT is remarkably different （chemisoption process） in comparison to the exterior sidewall of the tubes. Furthermore, the electronic structures and mulliken charge population of the considered complexes at their ground state are discussed within the context.

关键词： Fuel cells methanol functionalized SWCNTs adsorption ab initio calculations

Coating particles using liquids and foams based on viscous formulations with industrial mixers: Batch operation

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Particuology 2020年第3期18卷 13-24页

作者： d.Kontziampasis m.S.manga d.W.York School of Chemical and Process Engineering Faculty of EngineeringUniversity of LeedsLS29JTLeedsW.YorkshireUK

Particle or powder coating with viscous liquids has been essential in industry for surface modification purposes to induce and enhance specific *** paper evaluates the performance of using foams (of different bubble diameters) versus liquids as a means of coating powder beds based on viscous liquid *** with viscous liquids present numerous industrial challenges and therefore preparing foam equivalents can render the liquid component weak enough (through pre shearing to form the foam),to allow it to break up and coat particles under the shear forces exerted in a mixing *** this study,two shear mixers are used;the first type consists of paddles in different configurations attached to a single rotating shaft,whilst the second type is a commercial twin screw mixer (TSm).The quality of coating achieved on the bulk powder bed using liquids and foams (stained with a dye) is assessed by image analysis to determine the homogeneity of the color *** addition,scanning electron microscopy provides a tool to further investigate the coating quality of individual particles from the bulk *** results show that large bubble (centimeter size) foams are much more effective at distributing within the fluidized powder bed compared to the starting viscous liquid and small bubble foams (submillimeter size).Furthermore,there is a maximum ratio of foam to powder beyond which agglomeration occurs and is insufficient to fully coat the *** of individual particles is achieved in the case of the TSm,whereas SEm proves that the single shaft paddle mixer crushes the particles and subsequently granulates them together to form granules of a size comparable to the size of coated particles seen after coating with the TSm.

关键词： Powder coating Viscous liquid Foam Image analysis Foam rheology Surface modification

The Influence of the Imperfectness of Contact Conditions on the Critical Velocity of the moving Load Acting in the Interior of the Cylinder Surrounded with Elastic medium

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Computers, materials & Continua 2018年第2期54卷 103-136页

作者： m.Ozisik m.A.mehdiyev S.d.Akbarov department of mathematical Engineering Yildiz Technical UniversityDavutpasa Campus34220Esenler-Istanbul-Turkey Institute of mathematics and mechanics of the National Academy of Sciences of Azerbaijan 37041BakuAzerbaijan department of mechanical Engineering Yildiz Technical UniversityYildiz Campus34349BesiktasIstanbulTurkey

The dynamics of the moving-with-constant-velocity internal pressure acting on the inner surface of the hollow circular cylinder surrounded by an infinite elastic medium is studied within the scope of the piecewise homogeneous body model by employing the exact field equations of the linear theory of *** is assumed that the internal pressure is point-located with respect to the cylinder axis and is axisymmetric in the circumferential ***,it is assumed that shear-spring type imperfect contact conditions on the interface between the cylinder and surrounding elastic medium are *** focus is on the influence of the mentioned imperfectness on the critical velocity of the moving load and this is the main contribution and difference of the present paper the related other *** other difference of the present work from the related other ones is the study of the response of the interface stresses to the load moving velocity,distribution of these stresses with respect to the axial coordinates and to the *** the same time,the present work contains detail analyses of the influence of problem parameters such as the ratio of modulus of elasticity,the ratio of the cylinder thickness to the cylinder radius,and the shear-spring type parameter which characterizes the degree of the contact imperfection on the values of the critical velocity and stress *** numerical results are presented and *** particular,it is established that the values of the critical velocity of the moving pressure decrease with the external radius of the cylinder under constant thickness of that.

关键词： moving internal pressure critical velocity circular hollow cylinder surrounded by elastic medium shear-spring type imperfection interface stresses

Investigation of fission fragments average spin based on four dimensional Langevin dynamical model

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Chinese Physics C 2017年第2期41卷 124-131页

作者： d.Naderi m.Salimi department of Physics Faculty of Basic Sciences Razi University P.O.Box 67149 Kermanshah Iran

We applied the four dimensional Langevin dynamical model to investigate the average spin of fission fragments. Elongation, neck thickness, asymmetry parameter, and the orientation degree of freedom（K coordinate）are the four dimensions of the dynamical model. We assume that the collective modes depend on the emission angle of the fragments, then different parameters related to the average spin of fission fragments are calculated *** angle dependence of average spin of fission fragments is investigated by calculating the spin at angles 90？and165？. Also, the obtained results based on the transition state model at scission point are presented. One can obtain better agreement between the results of the dynamical model and experimental data in comparison with the results of the transition state model.

关键词： Langevin equations average spin fission fragments

Geochemical evidences of trace metal anomalies for finding hydrocarbon microseepage in the petroliferous regions of the Tatipaka and Pasarlapudi areas of Krishna Godavari Basin,India

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Petroleum Science 2013年第1期10卷 19-29页

作者： Rasheed m A Lakshmi m Rao P L S Kalpana m S dayal A m Patil d J microbiology Laboratory Petroleum Geochemistry Group National Geophysical Research Institute (Council of Scientific and Industrial Research)

The long-term seepage of hydrocarbons, either as macroseepage or microseepage, can set up near-surface oxidation reduction zones that favor the development of a diverse array of chemical and mineralogical changes. The bacterial oxidation of light hydrocarbons can directly or indirectly bring about significant changes in the values of pH and Eh of the surrounding environment, thereby also changing the stability fields of the different mineral species present in that environment. The paper reports the role of hydrocarbon microseepage in surface alterations of trace metal concentrations. In this study trace metal alterations were mapped that appear to be associated with hydrocarbon microseepages in the oil/ gas fields. A total of 50 soil samples were collected near oil and gas fields of the Tatipaka and Pasarlapudi areas of the Krishna Godavari Basin, Andhra Pradesh. The soil samples were collected from a depth of 2-2.5 m. The paper reports the chemical alterations associated with trace metals in soils that are related to hydrocarbon microseepages above some of the major oil and gas fields of this petroliferous region. Trace metals, such as scandium （Sc）, vanadium （V）, chromium （Cr）, cobalt （Co）, nickel （ni）, copper （Cu）, zinc （Zn）, barium （Ba） and strontium （Sr）, in soil samples were analyzed using inductively coupled plasma- mass spectrometry （ICP-mS）. The concentrations of Sc （8 to 40 mg/kg）, V （197 to 489 mg/kg）, Cr （106 to 287 mg/kg）, Co （31 to 52 mg/kg）, ni （65 to 110 mg/kg）, Cu （88 to 131 mg/kg）, Zn （88 to 471 mg/kg）, Ba （263 to 3,091 mg/kg） and Sr （119 to 218 mg/kg） were obtained. It was observed that the concentrations of trace elements were tremendously increased when they were compared with their normal concentrations in soils. The analysis of adsorbed soil gas showed the presence of high concentrations of YC2＋（C2H6, C3H8 and n-C4H10） ranging from 7 to 222 μg/kg respectively. Integrated studies of trace elements over adsorbed light gaseous hydrocarbons （2C2

关键词： Hydrocarbons microseepage trace metal alterations adsorbed soil gas Krishna Godavari Basin