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Cross-sectional warping and precision of the first-order shear deformation theory for vibrations of transversely functionally graded curved beams

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Applied mathematics and mechanics(English Edition) 2023年第12期44卷 2109-2138页

作者： u.N.ARIBAS m.AYDIN m.ATAlAY m.h.OmuRTAG Department of Civil Engineering Istanbul Medipol UniversityIstanbul 34810Türkiye

The warping may become an important factor for the precise transverse vibrations of curved ***,the first aim of this study is to specify the structural design parameters where the influence of cross-sectional warping becomes great and the first-order shear deformation theory lacks the precision *** outof-plane vibrations of the first-order shear deformation theory are compared with the warping-included vibrations as the curvature and/or thickness increase for symmetric and asymmetric transversely-functionally graded(TFG)curved *** second aim is to determine the influence of design parameters on the *** circular/exact elliptical beams are formed via curved mixed finite elements(mFEs)based on the exact curvature and *** stress-free conditions are satisfied on three-dimensional(3D)constitutive *** variation of functionally graded(FG)material constituents is considered based on the power-law *** cross-sectional warping deformations are defined over a displacement-type FE *** warping-included mFEs(W-mFEs)provide satisfactory 3D structural characteristics with smaller degrees of freedom(DOFs)compared with the brick *** Newmark method is used for the forced vibrations.

关键词： mixed finite element(mFE) free vibration forced vibration warping exact elliptical beam functionally graded(FG)beam

Exact solutions for magnetohydrodynamic nanofluids flow and heat transfer over a permeable axisymmetric radially stretching/shrinking sheet

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Chinese Physics B 2024年第2期33卷 108-114页

作者： u.S.mahabaleshwar G.P.Vanitha l.m.Pérez Emad h.Aly I.Pop Department of Studies in mathematics Davangere UniversityShivagangothriDavangereIndia Departamento de F´ısica FACIUniversidad de Tarapac´aCasilla 7DAricaChile Department of mathematics Faculty of EducationAin Shams UniversityRoxyCairoEgypt Department of mathematics Babes-Bolyai University400084 Cluj-NapocaRomania

We report on the magnetohydrodynamic impact on the axisymmetric flow of Al_(2)O_(3)/Cu nanoparticles suspended in h_(2)O past a stretched/shrinked *** the use of partial differential equations and the corresponding thermophysical characteristics of nanoparticles,the physical flow process is *** resultant nonlinear system of partial differential equations is converted into a system of ordinary differential equations using the suitable similarity *** transformed differential equations are solved *** of the magnetic parameter,solid volume fraction and stretching/shrinking parameter on momentum and temperature distribution have been analyzed and interpreted *** skin friction and Nusselt number were also *** addition,existence of dual solution was deduced for the shrinking sheet and unique solution for the stretching ***,Al_(2)O_(3)/h_(2)O nanofluid flow has better thermal conductivity on comparing with Cu/h_(2)O ***,it was found that the first solutions of the stream are stable and physically realizable,whereas those of the second ones are unstable.

关键词： magnetohydrodynamic nanofluid stretching/shrinking sheet axisymmetric flow analytical solution suction/injection

Brownian motion and thermophoresis effects on unsteady stagnation point flow of Eyring-Powell nanofluid: a Galerkin approach

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Communications in Theoretical Physics 2020年第12期72卷 71-82页

作者： Z h Khan m usman T Zubair m hamid R u haq State Key laboratory of hydraulics and mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu610065China BIC-ESAT College of EngineeringPeking UniversityBeijing 100871China State Key laboratory for Turbulence and Complex Systems Department of Mechanics and Engineering SciencePeking UniversityBeijing 100871China Institute of Ocean Research Peking UniversityBeijing 100871China School of mathematical Sciences Peking UniversityBeijing 100871China Department of mechanics and Engineering Science Fudan UniversityShanghai 200433China Department of Electrical Engineering Bahria UniversityIslamabad CampusIslamabad 44000Pakistan

This article concerns the analysis of an unsteady stagnation point flow of Eyring–Powell nanofluid over a stretching *** influence of thermophoresis and Brownian motion is also considered in transport *** nonlinear ODE set is obtained from the governing nonlinear equations via suitable *** numerical experiments are performed using the Galerkin scheme.A tabular form comparison analysis of outcomes attained via the Galerkin approach and numerical scheme(RK-4)is available to show the credibility of the Galerkin *** numerical exploration is carried out for various governing parameters,namely,Brownian motion,steadiness,thermophoresis,stretching ratio,velocity slip,concentration slip,thermal slip,and fluid parameters,and hartmann,Prandtl and Schmidt *** velocity of fluid enhances with an increase in fluid and magnetic parameters for the case of opposing,but the behavior is reversed for assisting *** Brownian motion and thermophoresis parameters cause an increase in temperature for both cases(assisting and opposing).The Brownian motion parameter provides a drop-in concentration while an increase is noticed for the thermophoresis *** the outcomes and the behavior of emerging parameters are illustrated *** comparison analysis and graphical plots endorse the appropriateness of the Galerkin *** is concluded that said method could be extended to other problems of a complex nature.

关键词： Eyring-Powell fluid stagnation point flow Brownian motion and thermophoresis Galerkin method

Characterization of surface liquid segregation in SSm-hPDC aluminium alloys 7075,2024,6082 and A201

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中国有色金属学会会刊：英文版 2010年第S3期20卷 847-851页

作者： h.mllER u.A.CuRlE E.P.mASuKu materials Science and manufacturing Council for Scientific and Industrial Research(CSIR)PretoriaSouth Africa

The surface liquid segregation(SlS) phenomenon in semi-solid metal-high pressure die casting(SSm-hPDC) plates of 7075,2024,6082 and A201 was investigated by different *** profiles were determined by firstly measuring the chemical composition of the surface of the plates using a Thermo Quantris optical emission spectrometer(OES).material was then removed by a grinding process followed by measurement of the amount of material removed and chemical *** profiles of the main alloying elements were plotted for the cross-section of the plates in the as-cast and T6(after solution treatment) temper *** hardness profiles from the surface to the centre of the plates were *** samples of cross-sections of the castings were prepared and evaluated using a scanning electron *** results show that surface liquid segregation in SSm-hPDC alloys causes significant differences in properties between the surface and the bulk of these castings in both the F and T6 temper conditions.

关键词： semi-solid metal(SSm) forming alloy 7075 alloy 2024 alloy 6082 alloy A201 surface liquid segregation

In search of a pan-coronavirus vaccine:next-generation vaccine design and immune mechanisms

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Cellular & molecular Immunology 2024年第2期21卷 103-118页

作者： S.Cankat m.u.Demael l.Swadling Division of Infection and Immunity Institute of Immunity and TransplantationUniversity College LondonPears BuildingLondon NW32PPUK

members of the coronaviridae family are endemic to human populations and have caused several epidemics and pandemics in recent *** this review,we will discuss the feasibility of and progress toward the ultimate goal of creating a pan-coronavirus vaccine that can protect against infection and disease by all members of the coronavirus *** will detail the unmet clinical need associated with the continued transmission of SARS-CoV-2,mERS-CoV and the four seasonal coronaviruses(hCoV-OC43,Nl63,hKu1 and 229E)in humans and the potential for future zoonotic *** will highlight how first-generation SARS-CoV-2 vaccines and natural history studies have greatly increased our understanding of effective antiviral immunity to coronaviruses and have informed next-generation vaccine *** will then consider the ideal properties of a pan-coronavirus vaccine and propose a blueprint for the type of immunity that may offer ***,we will describe a subset of the diverse technologies and novel approaches being pursued with the goal of developing broadly or universally protective vaccines for coronaviruses.

关键词： Vaccine Coronavirus Cross-reactive immunity Cross-protection universal

Synthesis of crystalline perovskite-structured SrTiO_3 nanoparticles using an alkali hydrothermal process

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International Journal of minerals,metallurgy and materials 2016年第1期23卷 109-115页

作者： u.K.N.Din T.h.T.Aziz m.m.Salleh A.A.umar Institute of microengineering and Nanoelectronics (ImEN) Universiti Kebangsaan Malaysia

We report an experimental route for synthesizing perovskite-structured strontium titanate （SrTiO3） nanocubes using an alkali hydrothermal process at low temperatures without further heating. Furthermore, we studied the influence of heating time （at 180℃） on the crystallinity, morphology, and perovskite phase formation of SrTiO3. The SrTiO3 powder, which is formed via nanocube agglomeration, transforms into cubic particles with a particle size of 120--150 nm after 6 h of hydrothermal sintering. The crystallinity and percentage of the perovskite phase in the product increased with heating time. The cubic particles contained 31.24at% anatase TiO2 that originated fi＇om the precursor. By varying the weight ratio of anatase TiO2 used to react with the strontium salt precursor, we reduced the anatase-TiO2 content to 18.8at%. however, the average particle size increased when the anatase-TiO2 content decreased.

关键词： strontium titanate nanoparticles anatase hydrothermal synthesis

magnesium uptake and Palygorskite Transformation Abilities of Wheat and Oat

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Pedosphere 2012年第6期22卷 834-841页

作者： m.h.SAlEhI l.TAhAmTANI Department of Soil Science College of AgricultureShahrekord UniversityShahrekord(Iran)

Weathering of clay minerals is a source of nutrients to plants. Palygorskite is a mg-rich fibrous clay mineral that commonly occurs in the soils and sediments of arid regions. Although many studies have examined the environmental conditions required for the formation and stability of palygorskite, information on the transformation of this mineral in the root zone （or rhizosphere） of agricultural crops is limited. This study explored the possibility of palygorskite transformation in the rhizosphere of wheat and oat and compared the ability of these crops to extract structural mg from palygorskite. The crops were cultivated in pots consisting of a mixture of sand from hamadan region, Iran and Florida palygorskite, irrigated with distilled water, and treated with either complete or mg-free nutrient solutions. After 100 d, mg uptake by the crops was measured. Clay-sized particles in each pot were also separated from the sand and were analyzed through X-ray diffraction （XRD）. The X-ray pattern of the particles was compared with that of the pure palygorskite particles （before cultivation）. The results showed that palygorskite could provide sufficient mg for the growth of wheat in the pots supplied with mg-free nutrient solution. In spite of the magnesium uptake by both plants from the palygorskite structure, no detectable peaks indicating the transformation of pmygorskite were recognized by XRD. A decrease of 1.05 nm in peak intensity was more obvious for the pots containing palygorskite and irrigated with mg-free nutrient solution than for the pots irrigated with complete nutrient solution. Although the decrease in peak intensity was greater for oat than wheat, indicating greater palygorskite weathering by oat, mg uptake by oat was low, as evidenced by the deficiency symptoms observed.

关键词： clay minerals nutrient solution rhizosphere weathering X-ray diffraction

Spectrophotometric determination of tranexamic acid using vanillin

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药学学报 2009年第2期44卷 175-180页

作者： F.m.A. Rind m.G.h. laghari A.h. memon u.R. mughal E Almani N. memon m.Y. Khuhawar m.l. maheshwari Faculty of Pharmacy University of Sindh Jamshoro Pakistan Institute of Chemistry Faculty of Natural Sciences University of Sindh Jamshoro Pakistan

A new spectrophotometric method has been examined for the determination of the tranexamic acid (TA) by derivatization with vanillin (VAN). The molar absorptivity of TA was calculated 25 160 l·mol-1·cm-1 at λmax 354 nm and obeyed the Beer's law within 0.5-2.5 μg·ml-1. The color reaction was highly stable and did not show any change in absorbance up to 24 h. The method was applied for the analysis of TA from capsules, injections and tooth pastes. The amounts of TA found in capsules, injections and tooth pastes of various pharmaceutical companies were observed with 249.0-250.9 mg/capsule, 249.3-250.7 mg/injection and 0.048%-0.049% in tooth pastes with relative standard deviation (RSD) 0.2%-5.0% (n = 3).

关键词：分光方法氨甲环酸显色反应药物化学

Wavelet analysis of stagnation point flow of non-Newtonian nanofluid

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Applied mathematics and mechanics(English Edition) 2019年第8期40卷 1211-1226页

作者： m.hAmID m.uSmAN R.u.hAQ4 Z.h.KhAN Wei WANG School of mathematical Sciences Peking UniversityBeijing 100871China BIC-ESAT College of EngineeringPeking UniversityBeijing 100871China State Key laboratory for Turbulence and Complex Systems Department of Mechanics and Engineering SciencePeking UniversityBeijing 100871China Department of Electrical Engineering Bahria UniversityIslamabad 44000Pakistan State Key laboratory of hydraulics and mountain River Engineering College of Water Resource & HydropowerSichuan UniversityChengdu 610065China Key laboratory of Advanced Reactor Engineering and Safety Ministry of Education Tsinghua UniversityBeijing 100084China

The wavelet approach is introduced to study the influence of the natural convection stagnation point flow of the Williamson fluid in the presence of thermophysical and Brownian motion effects. The thermal radiation effects are considered along a permeable stretching surface. The nonlinear problem is simulated numerically by using a novel algorithm based upon the Chebyshev wavelets. It is noticed that the velocity of the Williamson fluid increases for assisting flow cases while decreases for opposing flow cases when the unsteadiness and suction parameters increase, and the magnetic effect on the velocity increases for opposing flow cases while decreases for assisting flow cases. When the thermal radiation parameter, the Dufour number, and Williamson’s fluid parameter increase, the temperature increases for both assisting and opposing flow cases. meanwhile, the temperature decreases when the Prandtl number increases. The concentration decreases when the Soret parameter increases, while increases when the Schmidt number increases. It is perceived that the assisting force decreases more than the opposing force. The findings endorse the credibility of the proposed algorithm, and could be extended to other nonlinear problems with complex nature.

关键词： Williamson nanofluid heat and mass transfer stagnation point flow assisting and opposing flow Chebyshev wavelet method