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Transactions of Nonferrous Metals Society of China 2019年第10期29卷 2005-2026页

作者： Abhishek sharma vyas mani sharma Jinu PAUL Department of Mechanical Engineering Indian Institute of Technology

A comparative study on the surface properties of Al-SiC-multi walled carbon nanotubes (CNT) and Al-SiC-graphene nanoplatelets (GNP) hybrid composites fabricated via friction stir processing (FSP) was documented. Microstructural characterization reveals a more homogeneous dispersion of GNPs in the Al matrix as compared to CNTs. Dislocation blockade by SiC and GNP particles along with the defect-free interface between the matrix and reinforcements is also observed. Nanoindentation study reveals a remarkable ~207% and ~27% increment in surface nano-hardness of Al-SiC-GNP and Al-SiC-CNT hybrid composite compared to as-received Al6061 alloy, respectively. On the other hand, the microhardness values of Al-SiC-GNP and Al-SiC-CNT are increased by ~36% and ~17% relative to as-received Al6061 alloy, respectively. Tribological assessment reveals ~56% decrease in the specific wear rate of Al-SiC-GNP hybrid composite, whereas it is increased by ~122% in Al-SiC-CNT composite. The higher strength of Al-SiC-GNP composite is attributed to the mechanical exfoliation of GNPs to few layered graphene (FLG) in the presence of SiC. Also, various mechanisms such as thermal mismatch, grain refinement, and Orowan looping contribute significantly towards the strengthening of composites. Moreover, the formation of tribolayer by the squeezed-out GNP on the surface is responsible for the improved tribological performance of the composites. Raman spectroscopy and various other characterization methods corroborate the results.

关键词： friction stir processing graphene carbon nanotube hybrid composite wear

Nonlinear Coupling of Kinetic Alfvén Waves and Ion Acoustic Waves in the Inner Heliosphere

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Research in Astronomy and Astrophysics 2024年第10期24卷 143-160页

作者： mani K Chettri Vivek Shrivastav Rupak Mukherjee Nidhi Gaur R.P.sharma Hemam D.Singh Department of Physics Sikkim University DAV Public School Plasma Simulation Laboratory Department of Energy Science and EngineeringIndian Institute of Technology Delhi

We study the nonlinear coupling of kinetic Alfvén waves with ion acoustic waves applicable to the Earth’s radiation belt and near-Sun streamer belt solar wind using dynamical equations in the form of modified Zakharov *** simulations show the formation of magnetic field filamentary structures associated with density humps and dips which become turbulent at later times,redistributing the energy to higher *** magnetic power spectra exhibit an inertial range Kolmogorov-like spectral index value of-5/3 for k⊥ρi<1followed by a steeper dissipation range spectra with indices～-3 for the radiation belt case and ～-4 for the nearSun streamer belt solar wind case,here k⊥andρirepresent the wavevector component perpendicular to the background magnetic field and the ion thermal gyroradius,*** quasilinear theory in terms of the Fokker–Planck equation in the region of wavenumber turbulent spectra,we find the particle distribution function flattening in the superthermal tail population which is the signature of particle energization and plasma heating.

关键词： Sun: chromosphere Sun: corona Sun: heliosphere SOLAR-WIND TURBULENCE FIELD-ALIGNED CURRENTS ALFVEN WAVES ASTROPHYSICAL GYROKINETICS COHERENT STRUCTURES DISSIPATION RANGE PROBE SCALE ACCELERATION PLASMA

Concentration,sources and wet deposition of dissolved nitrogen and organic carbon in the Northern Indo-Gangetic Plain during monsoon

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Journal of Environmental Sciences 2021年第4期33卷 37-52页

作者： Hemraj Bhattarai Lekhendra Tripathee Shichang Kang Chhatra mani sharma Pengfei Chen Junming Guo Prakriti sharma Ghimire Earth System Science Programme and Graduate Division of Earth and Atmospheric Sciences The Chinese University of Hong KongHong KongChina State Key Laboratory of Cryospheric Science Northwest Institute of Eco-environment and ResourcesChinese Academy of Sciences(CAS)Lanzhou 730000China Key Laboratory of Tibetan Environment Changes and Land Surface Processes Institute of Tibetan Plateau ResearchCASBeijing 100101China Chinese Academy of Sciences(CAS)Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100085China Himalayan Environment Research Institute(HERI) KathmanduNepal Central Department of Environmental Science Tribhuvan UniversityKathmanduNepal Kathmandu Center for Research and Education(KCRE) KathmanduNepal

Precipitation represents an important phenomenon for carbon and nitrogen ***,the concentrations and fluxes of dissolved organic carbon(DOC)and total dissolved nitrogen(TDN)with their potential sources were analyzed in wet precipitation during summer monsoon from the Northern Indo-Gangetic Plain(IGP),important but neglected *** volume-weighted mean(VWM)concentration of DOC and TDN were 687.04 and 1210.23μg/L,***,the VWM concentration of major ions were in a sequence of NH_(4)^(+)>Ca^(2+)>SO_(4)^(2-)>Na^(+)>K^(+)>NO_(3)~->Cl~->Mg^(2+)>F~->NO_(2)~-,suggesting NH_(4)^(+)and Ca^(2+)from agricultural activities and crustal dust played a vital role in precipitation ***,the wet deposition flux of DOC and TDN were 9.95 and 17.06 kg/(ha year),*** wet deposition flux of inorganic nitrogen species such as NH_(4)^(+)-N and NO_(3)^(-)-N were 14.31 and 0.47 kg/(ha year),respectively,demonstrating the strong influence of emission sources and precipitation *** attribution from different analysis suggested the influence of biomass burning on DOC and anthropogenic activities(agriculture,animal husbandry)on nitrogenous *** air-mass back trajectory analysis indicated the influence of air masses originating from the Bay of Bengal,which possibly carried marine and anthropogenic pollutants along with the biomass burning emissions to the sampling *** study bridges the data gap in the less studied part of the northern IGP region and provides new information for policy makers to deal with pollution control.

关键词： Precipitation chemistry Dissolved organic carbon Total dissolved nitrogen Major ions Indo-Gangetic Plain

Nitrogenous and carbonaceous aerosols in PM_(2.5) and TSP during pre-monsoon:Characteristics and sources in the highly polluted mountain valley

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Journal of Environmental Sciences 2022年第5期34卷 10-24页

作者： Hemraj Bhattarai Lekhendra Tripathee Shichang Kang Pengfei Chen Chhatra mani sharma Kirpa Ram Junming Guo Maheswar Rupakheti Earth System Science Programme and Graduate Division of Earth and Atmospheric Sciences The Chinese University of Hong KongHong KongChina State Key Laboratory of Cryospheric Science Northwest Institute of Eco-environment and ResourcesChinese Academy of Sciences(CAS)Lanzhou 730000China Key Laboratory of Tibetan Environment Changes and Land Surface Processes Institute of Tibetan Plateau ResearchCASBeijing 100101China CAS Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100085China Himalayan Environment Research Institute(HERI) Kathmandu 44602Nepal Central Department of Environmental Sciences Tribhuvan UniversityKathmandu 44613Nepal Institute of Environment and Sustainable Development Banaras Hindu UniversityVaranasi 221005India Institute for Advanced Sustainability Studies Potsdam 14467Germany

This study reports for the first time a comprehensive analysis of nitrogenous and carbona-ceous aerosols in simultaneously collected PM_(2.5) and TSP during pre-monsoon(March-May 2018)from a highly polluted urban Kathmandu Valley(KV)of the Himalayan *** mean mass concentration of PM_(2.5)(129.8 μg/m^(3))was only-25%of TSP mass(558.7 μg/m^(3))indicating the dominance of coarser mode ***,the mean concentration as well as fractional contributions of water-soluble total nitrogen(WSTN)and carbonaceous species reveal their predominance in find-mode *** mean mass concentration of WSTN was 17.43±4.70 μg/m^(3)(14%)in PM_(2.5) and 24.64±8.07 μg/m^(3)(5%)in ***,the fractional contribution of total carbonaceous aerosols(TCA)is much higher in PM_(2.5)(~34%)than that in TSP(~20%).The relatively low OC/EC ratio in PM_(2.5)(3.03±1.47)and TSP(4.64±1.73)suggests fossil fuel combustion as the major sources of carbonaceous aerosols with contributions from secondary organic ***-day air mass back trajectories sim-ulated with the HYSPLIT model,together with MODIS fire counts indicate the influence of local emissions as well as transported pollutants from the Indo-Gangetic Plain region to the south of the Himalayan *** component analysis(PCA)also suggests a mixed contribution from other local anthropogenic,biomass burning,and crustal *** re-sults highlight that it is necessary to control local emissions as well as regional transport while designing mitigation measures to reduce the KV's air pollution.

关键词： Nitrogenous aerosol Carbonaceous aerosols Major ions Particulate pollution Kathmandu Valley(KV)

Validation of Vesical Imaging Reporting and Data System score for the diagnosis of muscle-invasive bladder cancer: A prospective cross-sectional study

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Asian Journal of Urology 2022年第4期9卷 467-472页

作者： Kumawat Ghanshyam vyas Nachiket sharma Govind Priyadarshi Shivam Gupta Bhagwan Sahay Singla Mohit Kumar Ashok Department of Urology Sawai Man Singh Medical College and HospitalJaipurRajasthanIndia

Objective:Vesical Imaging Reporting and Data System(VIRADS)score was developed to standardize the reporting and staging of bladder tumors on pre-operative multiparametric magnetic resonance *** helps in avoiding unnecessary repeat transurethral resection of bladder tumor in high-risk non-muscle-invasive bladder cancer *** study was done to determine the validity of VIRADS score prospectively for the diagnosis of muscleinvasive bladder ***:This study was conducted from March 2019 to March 2020 at Sawai Man Singh Medical College and Hospital,Jaipur,Rajasthan,*** admitted with the provisional diagnosis of bladder tumor were included as *** these patients underwent a 3 Tesla mpMRI to obtain a VIRADS score before they underwent transurethral resection of bladder tumor and these data were analyzed to evaluate the correlation of pre-operative VIRADS score with mus-cle invasiveness of the tumor in final biopsy ***:A cut-off of VIRADS≥4 for prediction of detrusor muscle invasion yielded a sensitivity of 79.4%,specificity of 94.2%,positive predictive value of 90.0%,negative predictive value of 87.5%,and diagnostic accuracy of 86.4%.A cut off of VIRADS≥3 for prediction of detrusor muscle invasion yielded a sensitivity of 91.2%,specificity of 78.8%,positive predictive value of 73.8%,negative predictive value of 93.2%,and accuracy of 83.7%.The receiver operating curve showed the area under the curve to be 0.922(95%confidence interval:0.862e0.983).Conclusion:VIRADS score appears to be an excellent and effective pre-operative radiological tool for the prediction of detrusor muscle invasion in bladder cancer.

关键词： Vesical Imaging Reporting and Data System Bladder tumor Multiparametric magnetic resonance imaging Detrusor invasion

Atmospheric particle-bound mercury in the northern Indo-Gangetic Plain region:Insights into sources from mercury isotope analysis and influencing factors

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Geoscience Frontiers 2022年第1期13卷 85-95页

作者： Junming Guo Lekhendra Tripathee Shichang Kang Qianggong Zhang Jie Huang Chhatra mani sharma Pengfei Chen Rukumesh Paudyal Dipesh Rupakheti State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Himalayan Environment Research Institute(HERI) KathmanduNepal Key Laboratory of Tibetan Environment Changes and Land Surface Processes Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100039China Central Department of Environmental Science Tribhuvan UniversityKathmanduNepal

Lumbini is a world heritage site located in the southern plains region of Nepal, and is regarded as a potential site for evaluating transboundary air pollution due to its proximity to the border with India. In this study, 82 aerosol samples were collected between April 2013 and July 2014 to investigate the levels of particulate-bound mercury(PBM) and the corresponding seasonality, sources, and influencing *** PBM concentration in total suspended particulate(TSP) matter ranged from 6.8 pg m^(-3) to351.7 pg m^(-3)(mean of 99.7 ± 92.6 pg m^(-3)), which exceeded the ranges reported for remote and rural sites worldwide. The Hg content(PBM/TSP) ranged from 68.2 ng g^(-1) to 1744.8 ng g^(-1)(mean of 446.9 ±312.7 ng g^(-1)), indicating anthropogenic enrichment. The PBM levels were higher in the dry season(i.e.,winter and the pre-monsoon period) than in the wet season(i.e., the monsoon period). In addition, the δ^(202) Hg signature indicated that waste/coal burning and traffic were the major sources of Hg in Lumbini during the pre-monsoon period. Meanwhile, precipitation occurring during photochemical processes in the atmosphere may have been responsible for the observed Δ^(199) Hg values in the aerosol samples obtained during the monsoon period. The PBM concentration was influenced mostly by the resuspension of polluted dust during dry periods and crop residue burning during the post-monsoon period. The estimated PBM deposition flux at Lumbini was 15.7 lg m^(-2) yr^(-1). This study provides a reference dataset of atmospheric PBM over a year, which can be useful for understanding the geochemical cycling of Hg in this region of limited data.

关键词： Particle-bound mercury Seasonality Mercury isotopes Deposition flux Indo-Gangetic Plain

Corrosion behavior of ultrafine-grained AA2024 aluminum alloy produced by cryorolling

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International Journal of Minerals,Metallurgy and Materials 2017年第11期24卷 1293-1305页

作者： P. Laxman mani Kanta V.C. Srivastava K. Venkateswarlu sharma Paswan B. Mahato Goutam Das K. Sivaprasad K. Gopala Krishna Department of Metallurgical & Materials Engineering National Institute of Technology Thiruchirappalli 620015 India National Metallurgical Laboratory Council of Scientific & Industrial Research Jamshedpur 831007 India National Aerospace Laboratories Council of Scientific & Industrial Research Bangalore 560017 India

The objectives of this study were to produce ultrafine-grained(UFG) AA2024 aluminum alloy by cryorolling followed by aging and to evaluate its corrosion behavior. Solutionized samples were cryorolled to ~85% reduction in thickness. Subsequent aging resulted in a UFG structure with finer precipitates of Al_2CuMg in the cryorolled alloy. The(1) solutionized and(2) solutionized and cryorolled samples were uniformly aged at 160°C/24 h and were designated as CGPA and CRPA, respectively; these samples were subsequently subjected to corrosion studies. Potentiodynamic polarization studies in 3.5 wt% NaCl solution indicated an increase in corrosion potential and a decrease in corrosion current density for CRPA compared to CGPA. In the case of CRPA, electrochemical impedance spectroscopic studies indicated the presence of two complex passive oxide layers with a higher charge transfer resistance and lower mass loss during intergranular corrosion tests. The improved corrosion resistance of CRPA was mainly attributed to its UFG structure, uniform distribution of fine precipitates, and absence of coarse grain-boundary precipitation and associated precipitate-free zones as compared with the CGPA alloy.

关键词： AA2024 alloy cryorolling ultrafine grains precipitation corrosion behavior

Catalytic Cracking of Waste Polypropylene in a Nitrogen Fluidized Bed Reactor

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Journal of Geoscience and Environment Protection 2016年第4期4卷 20-25页

作者： Anil vyas Suresh Kumar Singh Komal sharma Sukhwant Singh Chemical Engineering Department Jai Narain Vyas University Jodhpur India Civil Engineering Department Jai Narain Vyas University Jodhpur India Chemical Engineering Department MNIT Jaipur India

Polypropylene (PP) is rated first as volume leader in the plastic sector. Its non-biodegradable property poses serious environmental problem in case of disposal. The catalytic cracking of PP was performed with various catalysts i.e. ZSM-5, Zeolite, RB and SPS. The cracking was observed under different feed to catalyst ratio i.e. 1:1 to 5:1. The fluidized bed reactor was fabricated with arrangement to measure the temperature ranging from 100。C to 800。C. The effective of feed to catalyst ratio was found 3:1 at a temperature range of 420。C - 510。C and catalyst ZSM-5 gives maximum liquid conversion of waste PP. Conversion of PP to liquid fuel will not only resolve the problem of disposal of waste polypropylene plastic but also give a value aided product.

关键词： Waste PP Pyrolysis Catalytic Cracking ZSM-5 Zeolite Liquid Fuel

Electron Momentum Density and X-ray Structure Factors of Fcc-Copper

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World Journal of Condensed Matter Physics 2011年第3期1卷 70-76页

作者： Neha Munjal Pooja Bhambhani Vimal vyas Parvez Ahmad Alvi Ghanshyam sharma Bal Krishna sharma Department of Physics Banasthali University Banasthali-304022 India

In this paper, we report the ground state properties i.e. electron momentum density and X-ray structure factors of fcc-copper are presented. The Am241 Compton spectrometer, which uses 59.54 keV gamma-rays, has been used for the Compton profile measurement. To compare the experimental data, the Compton profiles within the framework of linear combination of atomic orbitals (LCAO) method using Hartree–Fock (HF), density functional (DF) and hybrid B3PW schemes embodied in the CRYSTAL06 code have been computed. Among the various theoretical calculations, it is found that the present experimental data is in very good agreement with the hybrid B3PW scheme. A real-space analysis of the experimental Compton profile shows the metal-like behavior of copper The structure factors for copper are computed using hybrid B3PW scheme and compared with available experimental and theoretical data.

关键词： Momentum Density LCAO Method Electronic Structure X-Ray Structure Factors Metallic Behavior Etc

Rice straw recycling: A sustainable approach for ensuring environmental quality and economic security

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Pedosphere 2023年第1期33卷 34-48页

作者： Anjani KUMAR Amaresh Kumar NAYAK Sandeep sharma Ansuman SENAPATI Debasis MITRA Bipasa MOHANTY Seenichamy Rathinam PRABHUKARTHIKEYAN Kuttalingam Gopalasubramanian SABARINATHAN Indra mani Rajendra Singh GARHWAL Sugitha THANKAPPAN Mahapatra Smruthi SAGARIKA Sergio DE LOS SANTOS-VILLALOBOS Periyasamy PANNEERSELVAM Crop Production Division Indian Council of Agricultural Research(ICAR)-National Rice Research InstituteCuttackOdisha 753006India Department of Soil Science Punjab Agricultural UniversityPunjab 141027India Department of Plant Pathology Agricultural College and Research InstituteTamil Nadu Agricultural UniversityKillikulamTuticorin 628252India Division of Agricultural Engineering ICAR-Indian Agricultural Research InstitutePusaNew Delhi 110012India Collage of Agriculture Chaudhary Charan Singh Haryana Agriculture UniversityHisarHaryana 125004India School of Agriculture and Biosciences Karunya Institute of Technology and SciencesCoimbatoreTamil Nadu 641141India Laboratorio de Biotecnología del Recurso Microbiano Instituto Tecnológico De SonoraSonora 85000México

One of the major challenges in Asian countries is the effective management of rice *** ensure food security for their ever-growing population,Asian countries grow more rice,leading to increasing rice straw *** of rice straw,a common practice,is detrimental to both environmental and human ***,if managed effectively,rice straw has the potential to safeguard the sustainability of agricultural ecosystems and to uplift the economic security of the population depending on rice *** management of rice straw involving minimum soil disturbance along with retention of residues alters the soil carbon cycle through reduced carbon emissions and increased levels of total soil organic *** alternative uses of rice straw,such as production of livestock feed,bioethanol,biochar,biogas,electricity,mushroom,and paper,can add prosperity to rice farmers’life by fetching extra *** is evident that efficient management of rice straw is of enormous economic ***,it is essential to create awareness among the different rice stakeholders of these alternative economic avenues associated with rice *** review is an attempt to provide effective options for sustainable rice straw management and rice straw value chains for harnessing its economic *** further identifies gaps in our understanding of the effects of rice straw on ecological sustainability,particularly concerning the multifaceted connections between the diverse mechanisms of rice agro-ecosystems,which may greatly influence food security in the 21st century.

关键词： microorganism residue management rice straw burning rotation tillage value addition