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Acta Mathematica Scientia 2015年第6期35卷 1437-1453页

作者： Ram U.verma Department of Mathematics Texas State University

First, a class of higher order exponential type hybrid （α,β, γ, η, p, h（.,.）, κ（., .）, w（.,., .）, ω（.,.,.）, θ）-invexities is introduced, second, some parametrically sufficient efficiency conditions based on the higher order exponential type hybrid invexities are established, and finally some parametrically sufficient efficiency results under the higher order exponential type hybrid （a,β, γ, ρ, h（.,.）, k（.,-）, w（-,., .）, w（.,., .）, 0）-invexities are investigated to the context of solving semiinfinite multiobjective fractional programming problems. The notions of the higher order exponential type hybrid （a, β, γ η, p, h（., .）, n（., .）, w（-,.,-）, ω（.,.,.）, 0）-invexities encompass most of the generalized invexities in the literature. To the best of our knowledge, the results on semiinfinite multiobjective fractional programming problems established in this communication are new and application-oriented toward multitime multi- objectve problems as well as multiobiective control problems.

关键词： semiinfinite fractional programming multiobjective fractional programming,Hanson-Antczak-type generalized HAα,β,γ,η,ρh-V-invex functions hy-(α,β,γ,η,ρh(.,.),k(.,.),w(.,.,.)w(.,.,.),θ-invexity)

Preparation by chemical co-precipitation, spectral and electrical characteristics of neodymium orthophosphate nanoparticles

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Journal of Rare Earths 2015年第5期33卷 535-544页

作者： Seema verma K.K.Bamzai Crystal Growth and Material Research Laboratory Department of Physics & Electronics University of Jammu

Nanoparticles of neodymium orthophosphate （NdPO4） were prepared through a facile wet co-precipitation technique. The X-ray diffraction （XRD） studies revealed the material belonging to monoclinic monazite phase with crystallite size of 30.8 nm. Scanning electron microscopic studies showed that the material was composed of a large number of agglomerated spherical particles having grain size of 92 nm. Thermogravimetric analysis suggested that the structural phase transition was seen above 800 °C. The spectroscopic investigations were carried out using Fourier transform infrared spectroscopy （FTIR）. UV-VIS-NIR ab-sorption spectrophotometer showed various transitions from the ground state 4I9/2 to various excited states within the 4f shell and the optical band gap came out to be 3.3 eV. The dielectric constant （ε′）, dielectric loss （tanδ） and ac conductivity ln（σac） were measured in the frequency range of 5 kHz to 1 MHz and in the temperature range of 40 to 500 °C. The dielectric measurement suggested that there was a shift in the value of transition temperature （Tc）, thereby indicating relaxor behaviour of the material. The activation energy value decreased with increase in frequency, thereby suggesting the role of mixed ionic-polaronic conduc-tivity.

关键词： nanoparticles spectroscopic dielectric properties rare earths

Polyaxial strength criterion and closed-form solution for squeezing rock conditions

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Journal of Rock Mechanics and Geotechnical Engineering 2020年第3期12卷 507-515页

作者： Rupesh Kumar verma Sarvesh Chandra Department of Civil Engineering Indian Institute of Technology KanpurKanpur208016India

In this paper,a nonlinear strength criterion is proposed using the average of intermediate(σ2)and minor(σ3)principal stresses in place of σ3 in Ramamurthy(1994)’s strength *** proposed criterion has the main advantages of negligible variation of strength parameters with confining stress and ability to link with conventional strength ***,a new closed-form solution based on the proposed criterion is derived and validated for Chhibro Khodri ***,analytical solutions including Singh’s elastoplastic theory,Scussel’s approach,and closed-form solutions based on conventional and modified Ramamurthy(2007)criteria are compared with the results of proposed *** is shown that the in situ squeezing pressure predictions made by the proposed approach are more ***,a parametric study of the present analytical solution is carried out,which displays explicit dependency of tunnel stability on internal support pressure and tunnel *** influence of tunnel geometry is observed to be dependent on the applied support pressure.

关键词： Intermediate principal stress Squeezing pressure Closed-form solution Polyaxial strength criterion

A CONTRIBUTION TO THE SCIENTIFIC FOUNDATIONS OF SYSTEMS ENGINEERING： SOLUTION SPACES AND REQUIREMENTS

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Journal of Systems Science and Systems Engineering 2017年第5期26卷 549-589页

作者： Alejandro Salado Roshanak Nilchiani Dinesh verma Grado Department of Industrial and Systems Engineering Virginia Tech Blacksburg VA 24061 USA School of Systems and Enterprises Stevens Institute of Technology Hoboken N J 07030 USA

Some researchers have suggested that scientific foundations expressed in a mathematical form are needed to thrust the success of systems engineering as a discipline on its own merit. In order to contribute the development of such systems science, this paper investigates from a foundational standpoint the relationships between stakeholder needs, system requirements, and sets of systems. Various theorems and corollaries are proposed and mathematically proven. The theoretical elements are presented as a foundation for the development of a science for requirements engineering. The proposed foundations are finally tested to mathematically describe, in a rigorous and precise manner, qualities of good requirements, which are otherwise traditionally defined using vague narrative. By showcasing practical examples of the theoretical aspects, the paper is intended to serve as a bridge between practitioners and theorists.

关键词： Systems science systems theory requirements engineering mathematical formulation,requirements qualities formal concepts

Changes in species composition, diversity and biomass of herbaceous plant traits due to N amendment in a dry tropical environment of India

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Journal of Plant Ecology 2015年第3期8卷 321-332页

作者： Punita verma R.Sagar Hariom verma Preeti verma Dharmendra K.Singh Department of Botany Banaras Hindu UniversityVaranasi-221005India

Aim European and North american studies have suggested that nitrogen(N)depositions reduce plant diversity and increase primary pro-ductivity due to changes in plant *** predict the vegetation response to future global change,experimental validations from other regions are widely *** assessed the effects of N treat-ment by urea fertilization on the diversity and biomass of the her-baceous plant traits(HPTs)in a dry tropical environment of *** Diversity and biomass of different HPTs were determined on the basis of data collected in year 2010,from 135,1 m×1 m plots dis-tributed over 15 *** plots were treated with urea fertilizer in different doses(Control,60 kgNha−1 yr−1 and 120 kg N ha−1yr−1)since 1st January *** plots were ordinated and data were subjected to appropriate statistical *** Findings Correspondence analysis(Ca)suggested uniqueness of species composition due to N *** number and biomass of the trait categories varied due to N fertilization and *** studied trait categories(except N-fixers)yielded maximum mean species number at moderate level of N *** levels of N fer-tilization exhibited different species diversity-primary productivity(D-P)***,study showed reduction in plant diver-sity due to increase in biomass at high rates of N *** Tall,erect,non N-fixers,annuals,grasses HPTs were favoured by N enrichment.N dose above 60 kg enhanced the biomass of fast grow-ing,erect,annuals,non N-fixers,nitrophilic *** changes in traits with N addition,especially the increase in annuals and grasses and decrease in typically N-rich N-fixers,have implications for sus-tainable cattle production.

关键词： biomass Ca ordination dry tropics N amendment herbaceous plant traits primary productivity species diversity

CaCO_3/TiO_2 Nanoparticles Based Dye Sensitized Solar Cell

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Journal of Materials Science & Technology 2014年第4期30卷 328-334页

作者： Manveen Kaur N.K.verma Nano Research Lab School of Physics and Materials ScienceThapar University

In this communication, the synthesis and structural, morphological, optical, and photo-electrochemical properties of TiO2 and CaCO3/TiO2 nanoparticles as well as their applications in dye sensitized solar cells （DSSCs）, have been reported. In an X-ray diffraction pattern of CaCO3/TiO2 nanoparticles, the peak at 29.41 ° of CaCO3 has been detected, demonstrating its coating on the surface of TiO2, which is further verified using high resolution-transmission electron microscopy, energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. The strong quenching in photoluminescence emission, in the case of CaCO3/TiO2 nanoparticles, has been attributed to the decrease in recombination rate of photo-generated electron-hole pairs. In the case of UV-visible reflectance spectra, the absorption edge for CaCO3/TiO2 nanoparticles has slightly been found to be blue-shifted as compared to bare TiO2 nanoparticles, which corresponds to an increase in energy band gap of the former. The dye desorption studies reveal that CaCO3/TiO2 electrodes adsorbed more dye than the bare TiO2 electrode. CaCO3/TiO2 based DSSC show improved photo- electrochemical properties compared to the bare TiO2 based DSSC as CaCO3 coating on mi02 forms an energy barrier, and, consequently suppressing the charge recombination, and, thus, improving the overall energy conversion efficiency （η） from 0.46% to 1.44% under the illumination of simulated light of 100 mW/cm2.

关键词： Dye sensitized solar cells (DSSCs) TiO2 nanoparticles CaCO3 Coating Recombination

Synthesis,Characterization and Biocompatibility of Potassium Ferrite Nanoparticles

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Journal of Materials Science & Technology 2014年第1期30卷 30-36页

作者： Lavanya Khanna N.K.verma Nano Research Lab School of Physics and Materials ScienceThapar University

In the present study, morphology, size distribution, structure, biocompatibility and magnetic properties of potassium ferrite nanoparticles （KFeO2 NPs）, synthesized by conventional sol-gel method have been reported. The formation of spherical nanoparticles with orthorhombic structure has been confirmed by scanning electron microscopy and X-ray diffraction. The particle size, as obtained by transmission electron microscopy has been found to be in the range of 4-7 nm. Further, the size distribution has been scrutinized using Analyse-it software, where a platykurtic feature in the size distribution was observed. Fourier transform-infrared spectroscopy and thermogravimetric analysis showed the formation of metal （Fe, K） bonds at Neel temperature of 337℃. Vibrating sample magnetometer analysis revealed the superparamagnetic behaviour of the synthesized KFeO2 NPs, with saturation magnetization of 25.72 emu/g. In vitro cytotoxicity test, using MTTassay, on T cell lines （Jurkat cells） showed that KFeO2 NPs are biocompatible at a particle concentration of 100μg/ml.

关键词： Potassium ferrite nanoparticles Magnetic nanoparticles Superparamagnetic behaviour Biocompatibility Cytotoxicity

A Cooperative Approach of Frequency Regulation Through Virtual Inertia Control and Enhancement of Low Voltage Ride-through in DFIG-based Wind Farm

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Journal of Modern Power Systems and Clean Energy 2022年第6期10卷 1519-1530页

作者： Preeti verma Seethalekshmi K. Bharti Dwivedi Department of Electrical Engineering Institute of Engineering and TechnologyLucknow 226021Uttar PradeshIndiawhich is a constituent institute of Dr.A.P.J.Abdul Kalam Technical UniversityLucknowUttar Pradesh(U.P.)India IEEE

Doubly-fed induction generator(DFIG)-based wind farms(WFs)are interfaced with power electronic *** interfaces are attributed to the low inertia generated in the WFs under high penetration and that becomes prevalent in a fault ***,transient stability enhancement along with frequency stability in DFIG-based WFs is a major concern in the present *** this paper,a cooperative approach consisting of virtual inertia control(VIC)and a modified grid-side converter(GSC)approach for low voltage ride-through(LVRT)is proposed to achieve fault ride-through(FRT)capabilities as per the grid code requirements(GCRs)while providing frequency support to the grid through a synthetic *** proposed approach provides LVRT and reactive power compensation in the *** participation of the VIC in a rotor-side converter(RSC)provides frequency support to the DFIG-based *** combined approach supports active power compensation and provides sufficient kinetic energy support to the system in a contingency *** studies are carried out in MATLAB/Simulink environment for symmetrical and unsymmetrical *** superiority of the proposed scheme is demonstrated through analysis of the performance of the scheme and that of a series resonance bridge-type fault current limiter(SR-BFCL).

关键词： Virtual inertia controller(VIC) doubly-fed induction generator(DFIG) fault ride-through(FRT)capability wind farm(WF) fault current limiter(FCL)

Endosulfan-mediated Biochemical Changes in the Freshwater Fish Clarias batrachus

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Biomedical and Environmental Sciences 2004年第1期17卷 47-56页

作者： G.TRIPATHI PRIYANKA verma Department of Zoology J.N.V.UniversityJodhpur-342001IndiaDepartment of ZoologyJ.N.V.UniversityJodhpur-342001India

Objective Endosulfan is an extremely toxic organochlorine pesticide to aquatic organisms which might be hampering fish health through impairment of metabolism sometimes leading to death. So an experimental protocol was designed to look at endosulfan effects on a number of selected biochemical endpoints as well as to develop a mechanistic understanding of biochemical effects of endosulfan in freshwater fish. Methods The adult freshwater catfish Clarias batrachus were collected and acclimatized to laboratory condition for two weeks prior to experimentation. The toxicity bioassay test of commercial grade endosulfan (35% EC) was conducted for 21 days to determine its initial lethal concentration. The fish were exposed to sublethal concentration of endosulfan (0.06 mg/L) for 21 days. Pesticide - withdrawal experiments were also performed to study recovery. Protein synthesis inhibitors were injected to know the possible mechanism of recovery. The specimens of C. batrachus were sacrificed and brain, liver and caudal white skeletal muscle were removed. Tissues were homogenized and fractions were obtained by differential centrifugation. The activities of citrate synthase (CS), glucose 6-phosphate dehydrogenase (G6-PDH) and lactate dehydrogease (LDH) were assayed spectrophotometrically. Similarly, DNA, RNA and protein content were measured as per standard procedure. Results The exposure of sublethal concentration of endosulfan decreased the activity of citrate synthase (CS) and glucose 6-phosphate dehydrogenase (G6-PDH) in the brain, liver and skeletal muscle of the freshwater catfish, C. batrachus. The brain lactate dehydrogenase (LDH) activity was also reduced in response to endosulfan toxicity. The maximum reduction in activities of these enzyme was 34%-43%. Withdrawal of endosulfan restored the enzyme activity to control level in all the three tissues. The recovery in enzyme activity appears to be due to dissociation of endosulfan or its metabolite(s) from the enzyme mole

关键词： Catfish Endosulfan CS G6-PDH LDH DNA RNA RNA/DNA ratio and protein

Optimizing management in autoimmune hepatitis with liver failure at initial presentation

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World Journal of Gastroenterology 2011年第16期17卷 2070-2075页

作者： Jonathan R Potts Sumita verma Department of Medicine Brighton and Sussex Medical School

Autoimmune hepatitis (AIH) is a disease of unknown etiology,its hallmark being ongoing hepatic *** its very nature,it is a chronic condition,although increasingly,we are becoming aware of patients with acute presentations,some of whom may have liver *** are very limited published data on patients with AIH with liver failure at initial diagnosis,which consist mostly of small retrospective *** a consequence,the clinical features and optimal management of this cohort remain poorly defined.A subset of patients with AIH who present with liver failure do respond to corticosteroids,but for the vast majority,an urgent liver transplantation may offer the only hope of long-term *** present,there is uncertainty on how best to stratify such a cohort into responders and non-responders to corticosteroids as soon as possible after hospitalization,thus optimizing their *** editorial attempts to answer some of the unresolved issues relating to management of patients with AIH with liver failure at initial ***,it must be emphasized that,at present,this editorial is based mostly on small retrospective studies,and it is an understatement that multicenter prospective studies are urgently needed to address this important clinical issue.

关键词： Autoimmune hepatitis Liver failure Liver transplantation Corticosteroids