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Magnetic and magnetotransport behavior of overdoped nanocrystalline Nd_(1-x)Sr_xMnO_3 (0.50≤x≤0.63)

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Journal of Rare Earths 2011年第7期29卷 654-659页

作者： Neelam Maikhuri Vasudha agarwal Anurag Gaur H.K.Singh Department of Physics National Institute of Technology Kurukshetra-136119 India National Physical Laboratory New Delhi-110012 India

The nanocrystalline samples of Nd1-xSrxMnO3 （NSMO）（x=0.5, 0.55, 0.60, 0.63） were synthesized by sol-gel based polymeric pre-cursor route. Structural, magnetic and magnetotransport properties were studied systematically. It was found that in the composition range （x=0.50-0.63）, Nd1-xSrxMnO3 showed paramagnetic to ferromagnetic （PM-FM） transition in the vicinity of TC～270 K but the FM phase was weakened as the Sr concentration increased. The appearance of weak ferromagnetism was explained in terms of the core-shell model. More-over, for x=0.63 sample, a second transition is observed below TC at T=185 K, which is possibly due to the appearance of A-AFM/ C-AFM or a mixture of both the phases. Resistivity vs temperature （ρ-T） curve showed that the resistivity of all the samples was much larger than the sin-gle crystals of corresponding compositions due to large contribution of the grain boundaries in the present nanocrystalline samples. In all samples, extrinsic kind of MR behavior dominated because of nanocrystalline nature of the samples, which was nearly of the same order （～10%） in all samples. However, the intrinsic kind of MR behavior was also significant in x=0.50 sample, because of the strongest FM feature in this sample.

关键词： manganites magnetoresistance spin polarized tunnelling rare earths

Emission profiling of diesel and gasoline cars at a city traffic junction

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Particuology 2015年第1期13卷 186-193页

作者： Avinash Kumar agarwal Tarun Gupta Prakhar Bothra Pravesh Chandra Shukla Engine Research Laboratory Department of Mechanical EngineeringIndian Institute of Technology Kanpur Department of Civil Engineering Indian Institute of Technology Kanpur

In congested urban roads, cars must stop at intersections because of city traffic lights. As a result, pedestri- ans and traffic police personnel are exposed to pollutants emanating from the tailpipe of various vehicles at such city trafficjunctions. In this study, various gasoline- and diesel-fueled cars complying with differ- ent emission standards were tested for their emissions in simulated city traffic junction conditions. The engine exhaust from these cars was subjected to physicochemical characterization at different engine speeds under no-load conditions. These engine conditions were chosen because the cars idle at differ- ent engine speeds at a city traffic junction. Gravimetric and real-time measurements were performed for the tailpipe exhaust sampled from these vehicles. Exhaust particles were collected on 47 mm diameter quartz filter papers and subjected to gravimetric analysis for determining the total particulate mass （TPM） and trace metals while the engines were operated at two different engine idling speeds, 1500 rpm （representing low idling） and 2500 rpm （representing high idling）. At similar engine operating condi- tions, TPM and trace metals were lower for the exhaust from gasoline engines compared to the exhaust from diesel engines. Real-time measurements were performed for particle-bound poly-aromatic hydro- carbons （PAHs）, particle number and size distribution, regulated gaseous emissions and smoke opacity of the exhaust at four different engine speeds, 1500, 2000, 2500, and 3000 rpm. Particle-bound PAHs showed a decreasing trend for the vehicles that complied with stricter vehicular emission standards. Higher particle peak number concentrations were observed for diesel exhausts compared to the results for gasoline exhaust. Regulated gaseous emissions were also comoared.

关键词： Traffic junctions Traffic stop emissions Particle number emission Particle mass emissions Diesel and gasoline fueled cars

An evaluation of the emission profile for two-wheelers at a traffic junction

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Particuology 2015年第1期13卷 112-119页

作者： Avinash Kumar agarwal Prakhar Bothra Tarun Gupta Pravesh Chandra Shukla Engine Research Laboratory Department of Mechanical EngineeringIndian Institute of Technology Kanpur Department of Civil Engineering Indian Institute of Technology Kanpur

Two-wheeler vehicles are an important mode of transportation in developing countries. However, the emissions from two-wheeler vehicles are significant. Urban two-wheeler vehicles with gasoline-fueled engines produce NOx and particulate matter emissions that affect urban air quality. During traffic light stops and programmed stops, for instance, pollutants are emitted and are dangerous to human health. In this experimental study, two-wheeler vehicles with different makes, technologies and engine capacities were tested for exhaust emissions including gravimetric and online measurements at different engine speeds and a no load condition at a simulated traffic junction. Gravimetric measurements were performed by collecting the particulate mass （at two engine speeds： 1500 and 2500 rpm） from a diluted engine-out exhaust on quartz filter paper. Next, these collected particulates were used to determine the presence of metals, as well as the benzene soluble organic fraction （BSOF）. The total particulate mass, BSOF and trace elements were slightly higher at a higher engine speed （2500 rpm）. Online measurements were performed by sampling the engine exhaust （at four engine speeds： 1500, 2000, 2500, and 3000rpm） and using online instruments to determine the particle number and size distribution, the particle-bound polyaromatic hydrocarbons （PAHs）, the gaseous emissions and the smoke opacity. Engines with higher cubic capacity emitted a higher concentration of nano-particles. The particle-bound PAH concentration increased as the engine speed increased, but this concentration was notably low for the highest engine speed tested （3000 rpm）. The regulated gaseous emissions increased as the engine speed increased for all vehicles.

关键词： Benzene soluble organic fraction (BSOF) Particle number and size distribution Trace elements Polyaromatic hydrocarbons (PAHs) Regulated gaseous emissions

The Future of Multilateralism in the Post-pandemic World

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China & World Economy 2023年第1期31卷 62-87页

作者： Ligang Song Vishesh agarwal Crawford School of Public Policy Australian National UniversityAustralia World Bank Australia

This paper applies an endogenous institutionalist framewwork to understand the evolution of the rules-based international trading system since the end of World WarⅡ.We argue that the initial success of the General Agreement on Trade and Tariffs and re-enforcement that led to the formation of the WTO can be explained by three major factors:the hegemonic position of the US,the belief that international trade would foster prosperity and peace,and Cold War ***,declining US hegemony along with a shift in global comparative advantage in labor-intensive manufacturing led to a shift from multilateral towards preferential trade agreements since the ***,the WTO faces several new challenges,including increasing geo-political competition between the US and China,increasing digitization of commerce,and disrupted supply chains following CO VID-19.A functioning WTO that facilitates global economic re-integration remains crucial to ensure a strong recovery from the pandemic and continued long-term prosperity and stability of the global economy.

关键词： endogenous institutional change GATT international trade institutions WTO

Free Vibration Analysis of RC Box-Girder Bridges Using FEM

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Sound & Vibration 2022年第2期56卷 105-125页

作者： Preeti agarwal Priyaranjan Pal Pradeep Kumar Mehta Motilal Nehru National Institute of Technology Allahabad Prayagraj211004India

The free vibration analysis of simply supported box-girder bridges is carried out using the finite element *** fundamental frequency is determined in straight,skew,curved and skew-curved box-girder *** is important to analyse the combined effect of skewness and curvature because skew-curved box-girder bridge behaviour cannot be predicted by simply adding the individual effects of skewness and *** first,an existing model is considered to validate the present approach.A convergence study is carried out to decide the mesh size in the finite element *** exhaustive parametric study is conducted to determine the fundamental frequency of box-girder bridges with varying skew angle,curve angle,span,span-depth ratio and cell *** skew angle is varied from 0°to 60°,curve angle is varied from 0°to 60°,span is changed from 25 to 50 m,span-depth ratio is varied from 10 to 16,and single cell&double cell are used in the present study.A total of 420 bridge models are used for parametric study in the *** shapes of the skew-curved bridge are also *** fundamental frequency of the skew-curved box-girder bridge is found to be more than the straight bridge,so,the skew-curved box-girder bridge is *** present study may be useful in the design of box-girder bridges.

关键词： Fundamental frequency skew-curved box-girder bridge single-cell double-cell curve angle skew angle FEM

Xanthogranulomatous cholecystitis:a premalignant condition?

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Hepatobiliary & Pancreatic Diseases International 2011年第2期10卷 179-184页

作者： Mila Ghosh Puja Sakhuja Anil K agarwal Department of Gastrointestinal Surgery GB Pant Hospita and Maulana Azad Medical College Department of Pathology GB Pant Hospita and Maulana Azad Medical College

BACKGROUND:Xanthogranulomatous cholecystitis(XGC)is an uncommon variant of chronic cholecystitis,characterized by marked thickening of the gallbladder wall and dense local *** often mimics a gallbladder carcinoma(GBC), and may coexist with GBC,leading to a diagnostic dilemma. Furthermore,the premalignant nature of this entity is not *** study was undertaken to assess the p53,PCNA and beta-catenin expression in XGC in comparison to GBC and chronic inflammation. METHODS:Sections from paraffin-embedded blocks of surgically resected specimens of GBC(69 cases),XGC(65), chronic cholecystitis(18)and control gallbladder(10)were stained with the monoclonal antibodies to p53 and PCNA, and a polyclonal antibody to beta-catenin.p53 expression was scored as the percentage of nuclei *** expression was scored as the product of the percentage of nuclei stained and the intensity of the staining(1-3).A cut-off value of 80 for this score was taken as a positive result. Beta-catenin expression was scored as type of expression-membranous,cytoplasmic or nuclear staining. RESULTS:p53 mutation was positive in 52%of GBC cases and 3%of XGC,but was not expressed in chronic cholecystitis and control gallbladders.p53 expression was lower in XGC than in GBC(P<0.0001).PCNA expression was seen in 65%of GBC cases and 11%of XGC,but not in chronic cholecystitis and control *** expression was higher in GBC than XGC(P=0.0001),but there was no significant difference between the XGC,chronic cholecystitis and control gallbladder ***-catenin expression was positive in the GBC,XGC, chronic cholecystitis and control gallbladder *** the expression pattern in XGC,chronic cholecystitis and control gallbladders was homogenously membranous,whereas in GBC the membranous expression pattern was altered to cytoplasmic and ***:The expression of p53,PCNA and beta-catenin in XGC was significantly different from GBC and similar to chronic cholecystitis,

关键词： xanthogranulomatous cholecystitis gallbladder cancer p53 PCNA beta-catenin

Camelina sativa,a short gestation oilseed crop with biofuel potential:Opportunities for Indian scenario

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Oil Crop Science 2021年第3期6卷 114-121页

作者： Ankur agarwal Om Prakash Madhu Bala Defence Institute of Bio-Energy Research Defence R&D OrganizationGoraparaoP.O.ArjunpurHaldwaniUttarakhand263139India

Camelina is an oilseed crop which is being commercially produced globally as feedstock for *** a non-edible oil bearing low input crop owing to its low fertilizer and water requirement,fits well for biofuel *** India,targets for biofuel blending has been set by New Biofuel Policy-2018 and to meet these targets efforts are being made to harness the potential of available feedstock in the *** these feedstock,contribution of short gestation oilseed bearing crop has been very *** has been introduced in India during 2009–10 as experimental crop by DIBER,*** then various efforts have made to standardize the production technology of this crop under various agro-climatic regions of the country,crop improvement,oil quality analysis and development of high energy *** has various advantages to offer for Indian biofuel *** paper reviews the potential of this crop for Indian Biofuel scenario.

关键词： Camelina False flax Production Agro-technology Crop improvement Economics

Existence of Solutions to Nonlinear Neumann Boundary Value Problems with p-Laplacian Operator and Iterative Construction

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Acta Mathematicae Applicatae Sinica 2011年第3期27卷 463-470页

作者： Li Wei Hai-yun Zhou Ravi P. agarwal School of Mathematics and Statistics Hebei University of Economics and Business Shijiazhuang 050061 China Institute of Applied Mathematics Ordnance Engineering College Shijiazhuang 050003 China Department of Mathematical Sciences Florida Institute of Technology Melbourne FL 32901 U.S.A.

By using some results of pseudo-monotone operator, we discuss the existence and uniqueness of the solution of one kind nonlinear Neumann boundary value problems involving the p-Laplacian operator. We also construct an... 详细信息

关键词： maximal monotone operator pseudo-monotone operator p-Laplacian operator iterative scheme

Special Considerations in the Management of Autoimmune Hepatitis in COVID-19 Hotspots:A Review

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Journal of Clinical and Translational Hepatology 2021年第4期9卷 568-575页

作者： Deepak Madhu Sanchit Sharma Ashish agarwal Anoop Saraya Department of Gastroenterology Aster MIMS CalicutKeralaIndia Department of Gastroenterology Caritas HospitalKottayamKeralaIndia Department of Gastroenterology and Human Nutrition All India Institute of Medical SciencesNew DelhiIndia Department of Gastroenterology All India Institute of Medical SciencesJodhpurRajasthanIndia

The ongoing coronavirus disease-2019(COVID-19)pandemic has necessitated special considerations in the management of *** way presence of pre-existing diseases or treatment for it predisposes to,alters course of,and changes the management of COVID-19,is of relevance and is being extensively *** hepatitis(AIH)is unique in that it is an autoimmune disease mandating treatment with immunosuppressive drugs,as well as a liver disease with potential for varying degrees of underlying *** use of immunosuppressive drugs could alter the risk of acquiring COVID-19,the clinical course and severity of COVID-19 and the degree of underlying liver fibrosis could alter the clinical outcomes of patients with *** this review,we try to summarize key areas relevant in understanding and improving the clinical care of patients with AIH in the current *** considerations required in the management of patients with AIH in COVID-19 hotspots have been outlined based on the current evidence.

关键词： Hepatitis Autoimmune Liver cirrhosis COVID-19 SARS-CoV-2 infection Immunosuppressive agents