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Memory response in a nonlocal micropolar double porous thermoelastic medium with variable conductivity under Moore-Gibson-Thompson thermoelasticity theory

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Journal of Ocean Engineering and Science 2023年第3期8卷 263-277页

作者： Shishir Gupta Rachaita Dutta Soumik Das Department of Mathematics and Computing Indian Institute of Technology(ISM)DhanbadJharkhand 826004India

The present study enlightens the two-dimensional analysis of the thermo-mechanical response for a mi-cropolar double porous thermoelastic material with voids(MDPTMWV)by virtue of Eringen’s theory of nonlocal ***-Gibson-Thompson(MGT)heat equation is introduced to the considered model in the context of memory-dependent derivative and variable *** employing the normal mode technique,the non-dimensional coupled governing equations of motion are solved to determine the an-alytical expressions of the displacements,temperature,void volume fractions,microrotation vector,force stress tensors,and equilibrated stress *** two-dimensional graphs are presented to demon-strate the influence of various parameters,such as kernel functions,thermal conductivity,and ***,different generalized thermoelasticity theories with variable conductivity are compared to visualize the variations in the distributions associated with the prior mentioned *** particu-lar cases are also discussed in the presence and absence of different parameters.

关键词： Memory-dependent derivative Eringen’s nonlocal elasticity theory Micropolar double porous thermoelastic material with voids Moore-Gibson-Thompson thermoelasicity Variable conductivity

One Step Synthesis and Growth Mechanism of Carbon Nanotubes

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Journal of Materials Science & Technology 2014年第2期30卷 112-116页

作者： Akshay Kumar K.Singh O.P.Pandey Sri Guru Granth Sahib World University School of Physics and Materials Science Thapar University

A simple one step, reproducible, synthesis route for carbon nanotubes was proposed. No external catalyst was used for the synthesis. These nanotubes were obtained after decomposition of acetone at 650 ℃ in a specially designed autoclave. The pressure generated due to decomposition of acetone played a vital role in the synthesis. The X-ray diffraction pattern and transmission electron microscopy of the sample showed that the diameter of nanotubes is in the range of 3-14 nm. The thermo gravimetric analysis showed 3% weight loss below 500 ℃; the content of amorphous carbon is very less. The growth mechanism of CNTs was also proposed in the present paper.

关键词： Nanostructures Chemical synthesis Electron diffraction Raman spectroscopy Defects

Influence of cobalt on performance of Cu-CeO2 catalysts for preferential oxidation of CO

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Journal of Rare Earths 2020年第9期38卷 941-950,I0001页

作者： Sachin Malwadkar Parthasarathi Bera C.V.V.Satyanarayana Catalysis Division CSIR-National Chemical LaboratoryPune 411008India Surface Engineering Division CSIR-National Aerospace LaboratoriesBengaluru 560017India

Copper and cobalt oxides supported on CeO2 were investigated for preferential oxidation of carbon monoxide(CO-PROX)in the presence of excess hydrogen and CO2.(Cuo)1-x(Co3 O4)x/3-(CeO2)2.5(x=0,0.25,0.50,0.75,0.85 and 1)catalysts were prepared by coprecipitation *** mixed oxide catalysts were characterized by several physicochemical techniques,such as BET surface area(SBET),X-ray diffraction(XRD),high resolution transmission electron microscopy(HRTEM),temperature programmed reduction(TPR)and X-ray photoelectron spectroscopy(XPS).XRD studies show the peaks related to CuO and Co3 O4 phases in copper and cobalt containing CeO2 *** average particle size of the CeO2 crystallites is in the range of 8-10 nm as evaluated from HRTEM *** studies demonstrate that Cu,Co and Ce in(cuO)1-x(Co3O4)x/3-(CeO2)2.5 catalysts are presented in+2 and+1,+3 and+2 and+4 and+3 oxidation states,*** catalyst with x=0.75 shows better activity and selectivity towards *** the catalyst with only copper(CuO-CeO2,x=0)shows good activity but reverse water gas shift(RWGS)reaction is noticed at high *** the other hand,RWGS reaction is suppressed on the cobalt containing CuO-ceO2 *** on CeO2 with x=1 shows hardly any activity for PRoX reaction at low *** methanation activity is observed on CuO-CeO2 or Co3O4-CeO2 *** contrast,combination of copper and cobalt on CeO2 shows methanation of CO where enhanced activity is observed with increasing in cobalt content.

关键词： CO-PROX Cu-CeO2 XRD XPS Methanation H2O addition

Peristaltic transport of rheological fluid:model for movement of food bolus through esophagus

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Applied Mathematics and Mechanics(English Edition) 2012年第3期33卷 315-332页

作者： J.C.MISRA S.MAITI Department of Mathematics Institute of Technical Education and ResearchSiksha 'O' Anusandhan UniversityBhubaneswar 751030India School of Medical Science and Technology & Center for Theoretical Studies Indian Institute of TechnologyKharagpur 721302India

Fluid mechanical peristaltic transport through esophagus is studied in the paper. A mathematical model has been developed to study the peristaltic transport of a rheological fluid for arbitrary wave shapes and tube lengths. The Ostwald-de Waele power law of a viscous fluid is considered here to depict the non-Newtonian behaviour of the fluid. The model is formulated and analyzed specifically to explore some important information concerning the movement of food bolus through esophagus. The analysis is carried out by using the lubrication theory. The study is particularly suitable for the cases where the Reynolds number is small. The esophagus is treated as a circular tube through which the transport of food bolus takes place by periodic contraction of the esophageal wall. Variation of different variables concerned with the transport phenomena such as pressure, flow velocities, particle trajectory, and reflux is investigated for a single wave as well as a train of periodic peristaltic waves. The locally variable pressure is seen to be highly sensitive to the flow index ＂n＂. The study clearly shows that continuous fluid transport for Newtonian/rheological fluids by wave train propagation is more effective than widely spaced single wave propagation in the case of peristaltic movement of food bolus in the esophagus.

关键词： non-Newtonian fluid food bolus esophagus peristaltic transport flow reversal single wave wave train particle trajectory

Negundoside,an irridiod glycoside from leaves of Vitex negundo,protects human liver cells against calcium-mediated toxicity induced by carbon tetrachloride

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World Journal of Gastroenterology 2008年第23期14卷 3693-3709页

作者： Sheikh A Tasduq Peerzada J Kaiser Bishan D Gupta Vijay K Gupta Rakesh K Johri Indian Institute of Integrative Medicine CSIRJammu-Tawi-180001Jammu and KashmirIndia

AIM： To evaluate the protective effect of 2′-p-hydroxy benzoylmussaenosidic acid [negundoside （NG）, against carbon tetrachloride （CCl4）-induced toxicity in HUH-7 cel Is.METHODS： CCI4 is a well characterized hepatotoxin, and inducer of cytochrome P450 2E1 （CYP2E1）-mediated oxidative stress. In addition, lipid peroxidation and accumulation of intracellular calcium are important steps in the pathway involved in CCl4 toxicity. Liver cells （HUH-7） were treated with CCI4, and the mechanism of the cytoprotective effect of NG was assessed. Silymarin, a known hepatoprotective drug, was used as control. RESULTS： NG protected HUH-7 cells against CCl4 toxicity and loss of viability without modulating CYP2E1 activity. Prevention of CCl4 toxicity was associated with a reduction in oxidative damage as reflected by decreased generation of reactive oxygen species （ROS）, a decrease in lipid peroxidation and accumulation of intracellular Ca^2＋ levels and maintenance of intracellular glutathione homeostasis. Decreased mitochondrial membrane potential （MMP）, induction of caspases mediated DNA fragmentation and cell cycle arrest, as a result of CCl4 treatment, were also blocked by NG. The protection afforded by NG seemed to be mediated by activation of cyclic adenosine monophosphate （cAMP） synthesis and inhibition of phospholipases （cPLA2）. CONCLUSION： NG exerts a protective effect on CYP2E1-dependent CCl4 toxicity via inhibition of lipid peroxidation, followed by an improved intracellular calcium homeostasis and inhibition of Ca^2＋-dependent proteases.

关键词： Negundoside Silymarin HUH-7 Carbon tetrachloride CYP 2E1 Oxidative stress Calcium Toxicity

High Linear Voltage Gain in QZNC Through Synchronizing Switching Circuits

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Intelligent Automation & Soft Computing 2023年第4期36卷 895-910页

作者： S.Harika R.Seyezhai A.Jawahar Department of EEE REC LabSSN College of EngineeringChennai603110Tamil NaduIndia Department of ECE SSN College of EngineeringChennai603110Tamil NaduIndia

The solar powered systems require high step-up converter for efﬁcient energy *** this,quasi-impedance network converter has been *** quasi-impedance network converter(QZNC)is of two types:type-1 and type-2 conﬁ*** the type-1 and type-2 QZNC conﬁgurations have drooping voltage gain proﬁle due to presence of high switching *** overcome this,a new quasi-impedance network converter synchronizing the switching circuit with low frequency noise has been *** this paper,the proposed QZNC con-ﬁguration utilizes the current controlling diode to prevent the output voltage ***,the suggested topology provides linear high voltage gain proﬁle,low load voltage ripple,and reduced impedance network stress and device ***-fore,the efﬁciency of proposed QZNC has been *** topology descrip-tion,working principle,parameter design and comparison with traditional converters are ***ﬁnally,both simulation and practical results are presented to conﬁrm the converter characteristics and *** the results,it has been found that the performance of the suggested topology is better as it achieves a higher efﬁciency of 81%and hence,it is suitable for high power applications.

关键词： Quasi impedance network converter(QZNC) voltage ripple network stress device stress and efﬁciency

Layered double hydroxide using hydrothermal treatment： morphology evolution, intercalation and release kinetics of diclofenac sodium

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Frontiers of Materials Science 2017年第4期11卷 395-409页

作者： Mathew JOY SrividhyaJ. IYENGAR Jui CHAKRABORTY Swapankumar GHOSH Project Management Division CSIR-Central Glass & Ceramic Research Institute Kolkata-700032 India Bioceramics & Coating Division CSIR-Central Glass & Ceramic Research Institute Kolkata-700032 India

The present work demonstrates the possibilities of hydrothermal trans- formation of Zn-AI layered double hydroxide （LDH） nanostructure by varying the synthetic conditions. The manipulation in washing step before hydrothermal treatment allows control over crystal morphologies, size and stability of their aqueous solutions. We examined the crystal growth process in the presence and the absence of extra ions during hydrothermal treatment and its dependence on the drug （diclofenac sodium （Dic- Na）） loading and release processes. Hexagonal plate-like crystals show sustained release with -90% of the drug from the matrix in a week, suggesting the applicability of LDH nanohybrids in sustained drug delivery systems. The fits to the release kinetics data indicated the drug release as a diffusion-controlled release process. LDH with rod-like morphology shows excellent colloidal stability in aqueous suspension, as studied by photon correlation spectroscopy.

关键词： layered double hydroxide crystal morphology hydrothermal treatment drug loading

Photochemical Transformations of Some 2-（5-Methylthiophen-2-yl）-3-[（naphthalen-2-yl）methoxy]-4H-chromen-4-ones Involving Type-II Process

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Chinese Journal of Chemistry 2011年第4期29卷 745-750页

作者： Kamboj, Ramesh C Kumar, Dinesh Sharma, Geeta Arora, Rita Department of Chemistry Kurukshetra University Kurukshetra 136119 India

Photo-irradiation of 2-（5-methylthiophen-2-yl）-3-[（naphthalen-2-yl）methoxy]-4H-chromen-4-ones yielded the fascinating angular tetracyclic products via cyclization involving both 2-thienyl ring and naphthylmethoxy group via 1,4-biradical generated in the Norrish type-II process. The stereochemical dispositions of the products were determined by MM2 energy minimized programme and spectroscopic analysis.

关键词： type-II reaction radicals thienylchromone sigmatropic rearrangement substituent effects

Viscosity and Diffusion Effects at the Boundary Surface of Viscous Fluid and Thermoelastic Diffusive Solid Medium

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Advances in Applied Mathematics and Mechanics 2011年第2期3卷 219-238页

作者： Rajneesh Kumar Tarun Kansal Department of Mathematics Kurukshetra UniversityKurukshetra-136119India

This paper concentrates on the wave motion at the interface of viscous compressible fluid half-space and homogeneous isotropic,generalized thermoelastic diffusive *** wave solutions in both the fluid and thermoelastic diffusive half-spaces have been investigated;and the complex dispersion equation of leaky Rayleigh wave motion have been *** phase velocity and attenuation coefficient of leaky Rayleigh waves have been computed from the complex dispersion equation by using the Muller’s *** amplitudes of displacements,temperature change and concentration have been *** effects of viscosity and diffusion on phase velocity and attenuation coefficient of leaky Rayleigh waves motion for different theories of thermoelastic diffusion have been depicted graphi*** magnitude of heat and mass diffusion flux vectors for different theories of thermoelastic diffusion have also been computed and represented graphically.

关键词： Viscous compressible fluid isotropic thermoelastic diffusion phase velocity attenuation coefficient.