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Defence Technology（防务技术） 2019年第2期15卷 227-232页

作者： A.Manash p.kumar Department of Mechanical Engineering VVIT Department of Mechanical Engineering K N Modi Engineering and Technology

In the present investigation an effort has been made to understand the thermal decomposition and burn rate characteristics of Ap as oxidizer and pVC and HTpB as fuel binder in composite solid propellant. The burning rate study has been carried out at ambient and different pressures of 2.068 Mpa, 4.760 Mpa,6.895 Mpa. The mechanism of thermal decomposition of each composition have also been determined by NETZSCH simultaneous thermal analyser, comprising differential scanning calorimeter(DSC) and thermo-gravimetric analyser(TGA). An effort has been made to study the burn rate and decomposition of fuel binder and oxidizer in presence of Fe_2O_3 and also their overall impact on combustion of propellant.

关键词： Thermal decomposition Burn rate Thermo-gravimetric analysis Ap pVC HTpB Fe2O3

Rare alleles from tolerant cultivars are useful for generating salt-tolerant rice

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Molecular plant 2023年第2期16卷 306-307页

作者： pannaga Krishnamurthy prakash p.kumar Department of Biological Sciences and Research Centre on Sustainable Urban Farming National University of Singapore14 Science Drive 4Singapore 117543Singapore

Salinity is a major environmental stress limiting crop *** gloomy forecast that by 2025 about 50%of farmland will be severely affected by salinity,coupled with the constantly increasing demand for food,drives home the urgent need to generate salt-tolerant crop plants for ensuring world food *** tolerance is a complex phenomenon regulated by the interplay of multiple genes and factors.

关键词： cultivar farmland alleles

Numerical solution of generalized DpL model using wavelet method during thermal therapy applications

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International Journal of Biomathematics 2019年第3期12卷 169-190页

作者： p.kumar K.N.Rai Department of Mathematics H. R. College Amnour (A Constituent Unit of J. P. University) Saran-841401 India Department of Mathematical Sciences IIT (BHU) Varanasi India

In this paper, generalized dual-phase-lag (DpL) model has been studied for the numerical analysis of spatial variation of temperature within living biological tissues during thermal therapy applications. A new hybrid numerical scheme based on finite difference scheme and Chebyshev wavelet Galerkin method are used to solve the generalized DpL model with constant heat flux boundary condition. Multi-resolution and multi-scale computational property of Chebyshev wavelet in the present case localizes small scale variations of solution and fast switching of functional bases. Our study demonstrates that due to presence of coupling factor (convection–perfusion), generalized DpL model predicts lower temperature than classical DpL and pennes model at the tumor position. Higher values of phase lag times results in lower temperature at the tumor position. But, in case of variation of phase lag time due to temperature gradient, the nature of temperature profile also depends on the spatial coordinate. The effect of the blood temperature, porosity and interfacial convective heat transfer on temperature distribution has been investigated. It is found that larger values of porosity and interfacial convective heat transfer results in lower temperature at the tumor position. Also, both porosity and interfacial convective heat transfer are pronounced more at higher values. The whole analysis is presented in dimensionless form.

关键词： Chebyshev wavelet Galerkin method Generalized DpL model Nonequilibrium bioheat transfer Thermal therapy

Regulation of Seed Germination:The Involvement of Multiple Forces Exerted via Gibberellic Acid Signaling

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Molecular plant 2019年第10期12卷 24-26页

作者： pratibha Ravindran prakash p.kumar Department of Bioiogical Sciences National University of Singapore Singapore 117543Singapore

Seed germination is a key step in the life cycle of all seed plants, and it is of immense significance in *** is controlled by multiple environmental cues such as light and moisture,and endogenous factors,especially *** acid (GA)has long been identified as a critical hormone in the regulation of seed germination by countering the inhibition imposed by abscisic acid (ABA)(Holdsworth et al.,2008;Lee et al.,2010).

关键词： life plants Gibberellic acid

RISC assembly and post-transcriptional gene regulation in Hepatocellular Carcinoma

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Genes & Diseases 2020年第2期7卷 199-204页

作者： prasanna K.Santhekadur Divya p.kumar Department of Biochemistry Center of Excellence in Molecular Biology&Regenerative MedicineJSS Medical CollegeJSS Academy of Higher Education and ResearchMysoreIndia

RNA-induced silencing complex(RISC)is one of the basic eukaryotic cellular machinery which plays a pivotal role in post-transcriptional gene *** of miRNAs and their role in gene regulation have changed the course of modern *** method of gene silencing using small interfering RNAs and miRNAs has become major tool in molecular biology and genetic *** Carcinoma(HCC)is a very common malignancy of liver in developing countries and due to various risk factors;the prevalence of this disease is rapidly increasing throughout the *** exists an imbalance in interplay between oncogenes and tumor suppressor genes and their regulation plays a major role in HCC growth,development and *** regulatory function of RISC and miRNAs make them a very important mediators of cancer signaling in ***,targeting the RISC complex for HCC therapy is the need of the time.

关键词： Inflammation miRNA Oncogenes Regulation Tumor suppressor genes

Experimental studies and phase field modeling of microstructure evolution during solidification with electromagnetic stirring

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中国有色金属学会会刊：英文版 2010年第S3期20卷 774-780页

作者： p.GERALD TENNYSON p.kumar H.LAKSHMI G.pHANIkumar p.DUTTA Department of Metallurgical and Materials Engineering Indian Institute of Technology National Facility for Semisolid Forming Department of Mechanical EngineeringIndian Institute of Science

Thixocasting requires manufacturing of billets with non-dendritic *** alloy A356 billets were produced by rheocasting in a mould placed inside a linear electromagnetic *** heat treatment was used to produce a transition from rosette to globular *** current and the duration of stirring were explored as control *** induction heating of the billet during stirring was quantified using experimentally determined thermal *** effect of processing parameters on the dendrite fragmentation was *** computational modeling of the process was performed using phase-field modeling of alloy solidification in order to gain insight into the process of morphological changes of a solid during this process.A non-isothermal alloy solidification model was used for *** morphological evolution under such imposed thermal cycles was simulated and compared with experimentally determined *** scaling using the thermosolutal diffusion distances was used to overcome computational difficulties in quantitative comparison at system *** results were interpreted in the light of existing theories of microstructure refinement and globularisation.

关键词： electromagnetic stirring non-dendritic phase field modeling microstructure

Induction reheating of A356.2 aluminum alloy and thixocasting as automobile component

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中国有色金属学会会刊：英文版 2010年第S3期20卷 961-967页

作者： H.LAKSHMI M.C.VINAY kumar RAGHUNATH p.kumar V.RAMANARAYANAN K.S.S.MURTHY p.DUTTA National Facility for Semisolid Forming Department of Mechanical EngineeringIndian Institute of Science Department of Electrical Engineering Indian Institute of Science

The development work for producing an automobile component by thixocasting using A356.2 alloy was *** the first step,the alloy was electromagnetically stirred and solidified to produce a billet with non-dendritic *** microstructure depended on several process parameters such as stirring intensity,stirring frequency,cooling rate,and melt initial *** a series of computational studies and controlled experiments,a set of process parameters were identified to produce the best *** of a billet with non-dendritic microstructure to a semisolid temperature was the next step for thixo-casting of the *** reheating process was characterized for various reheating cycles using a vertical-type reheating *** induction heating cycle was optimized to obtain a near-uniform temperature distribution in radial as well as axial direction of the billet,and the heating was continued until the liquid fraction reached about 50%.These parameters were determined with the help of a computational fluid dynamics(CFD) model of die filling and solidification of the semisolid *** heated billets were subsequently thixo-cast into automobile components using a real-time controlled die casting *** results show that the castings are near net shape,free from porosity,good surface finish and have superior mechanical properties compared to those produced by conventional die casting processes using the same alloy.

关键词： aluminum alloy thixo-casting electromagnetic stirring induction reheating process parameters

IMpEDANCE SpECTROSCOpY AND AC CONDUCTIVITY STUDIES OF FERROELECTRIC(K_(0.5)Na_(0.5))NbO_(3)CERAMICS

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Journal of Advanced Dielectrics 2011年第3期1卷 351-356页

作者： p.pALEI p.kumar National Institute of Technology Rourkela 769008 India

Lead free(K_(0.5)Na_(0.5))NbO_(3)(KNN)ceramics were prepared by conventional solid state reaction *** single perovskite phase formation,calcination temperature was optimized at 850℃for 6h,whereas for dense morphology the sintering of the ceramic was carried out at 1120℃for 4h.X-ray diffraction XRD analysis confirmed the formation of single phase with orthorhombic structure at room *** analysis and AC conductivity studies of the KNN sample was carried out in the temperature range of 703-773 *** study showed the increase in conducting behavior at higher *** temperature dependence of AC conductivity indicated that the conduction process is due to doubly ionized oxygen vacancies in the higher temperature region.

关键词： perovskite sintering AC conductivity impedance oxygen vacancies

Hepatotoxic Alterations Induced by Subchronic Exposure of Rats to Formulated Fenvalerate (20% EC) by Nose Only Inhalation

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Biomedical and Environmental Sciences 2004年第3期17卷 309-314页

作者： U.MANI A.K.pRASAD V.SURESHkumar p.kumar KEWAL LAL B.K.MAJI K.K.DUTTA Inhalation Toxicology Laboratory and Animal House Industrial Toxicology Research Centre M. G. Marg P. Box. No.80 Lucknow-226 001 IndiaInhalation Toxicology Laboratory and Animal House Industrial Toxicology Research Centre M. G. Marg P. Box. No.80 Lucknow-226 001 IndiaInhalation Toxicology Laboratory and Animal House Industrial Toxicology Research Centre M. G. Marg P. Box. No.80 Lucknow-226 001 India Inhalation Toxicology Laboratory and Animal House Industrial Toxicology Research Centre M. G. Marg P. Box. No.80 Lucknow-226 001 IndiaInhalation Toxicology Laboratory and Animal House Industrial Toxicology Research Centre M. G. Marg P. Box. No.80 Lucknow-226 001 India

Objective Fenvalerate (20% EC) is a synthetic pyrethroid, which is commonly used in India by farmers for the protection of many food and vegetable crops against a wide variety of insects. However, its inhalation toxicity data is very limited in the literature due to the fact that the exposure levels associated with these effects were usually not reported. Hence, inhalation exposure was carried out to investigate the hepatotoxic effects. Method Adult male rats were exposed to fen for 4 h/day, 5 days a week for 90 days by using Flow past Nose Only Inhalation Chamber. Sham treated control rats were exposed to compressed air in the inhalation chamber for the same period. Results The results indicated hepatomegaly, increased activities of serum clinical enzymes (indicative of liver damage/dysfunction) along with pronounced histopathological damage of liver. Conclusion The hepatotoxic potential of formulated Fen (20% EC) in rats exposed by nose only inhalation is being reported for the first time and warrant adequate safety measures for human beings exposed to this insecticide, particularly by inhalation route.

关键词： Fenvalerate Rat Inhalation Hepatotoxicity

Nonionic surfactant vesicular systems for effective drug delivery—an overview

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Acta pharmaceutica Sinica B 2011年第4期1卷 208-219页

作者： Gannu p.kumar pogaku Rajeshwarrao Department of pharmaceutics Talla Padmavathi College of PharmacyWarangal 506002India

Vesicular systems are a novel means of drug delivery that can enhance bioavailability of encapsulated drug and provide therapeutic activity in a controlled manner for a prolonged period of *** were the first such system but they suffer from a number of drawbacks including high cost and lack of stability at various *** are a nonionic surfactant vesicular system,which can be easily and reliably made in the *** factors affect noisome formation such as the method of manufacture,nature of surfactant and encapsulated drug,temperature at which the lipids are hydrated and the critical packing *** review describes all aspects of niosomes including their different compositions,the various methods of preparation,the effect of changing manufacturing parameters,methods of characterization,factors that affect their stability,their use by various routes of administration,their therapeutic applications and the most important *** review also provides detailed information of the various types of niosomes that provide effective drug delivery.

关键词： Niosomes Nonionic surfactants Transferosomes Discomes Elastic niosomes proniosomes