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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 foothills.The 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 aerosols.However,the mean concentration as well as fractional contributions of water-soluble total nitrogen(WSTN)and carbonaceous species reveal their predominance in find-mode aerosols.The 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 TSP.Moreover,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 aerosols.Five-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 foothills.Principal component analysis(PCA)also suggests a mixed contribution from other local anthropogenic,biomass burning,and crustal sources.Our 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)

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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 deposition.Here,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 area.The volume-weighted mean(VWM)concentration of DOC and TDN were 687.04 and 1210.23μg/L,respectively.Similarly,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 chemistry.Moreover,the wet deposition flux of DOC and TDN were 9.95 and 17.06 kg/(ha year),respectively.The 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 volume.Source attribution from different analysis suggested the influence of biomass burning on DOC and anthropogenic activities(agriculture,animal husbandry)on nitrogenous species.The 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 site.This 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

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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 factors.The 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

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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 straw.To ensure food security for their ever-growing population,Asian countries grow more rice,leading to increasing rice straw generation.Burning of rice straw,a common practice,is detrimental to both environmental and human health.However,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 farming.Judicious 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 carbon.Several 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 income.It is evident that efficient management of rice straw is of enormous economic value.Therefore,it is essential to create awareness among the different rice stakeholders of these alternative economic avenues associated with rice straw.This review is an attempt to provide effective options for sustainable rice straw management and rice straw value chains for harnessing its economic potential.It 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

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搅拌摩擦加工制备石墨烯和碳纳米管增强Al6061-SiC复合材料的显微组织演变及表面性能（英文）

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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

对比研究多壁碳纳米管(CNT)和石墨烯纳米片(GNP)对Al-SiC基复合材料表面性能的影响,用搅拌摩擦法分别制备Al-SiC-CNT和Al-SiC-GNP复合材料。显微组织表征表明,与CNTs相比,GNPs在铝基体中的分散更加均匀。此外,还观察到SiC和GNP颗粒对位... 详细信息

对比研究多壁碳纳米管(CNT)和石墨烯纳米片(GNP)对Al-SiC基复合材料表面性能的影响,用搅拌摩擦法分别制备Al-SiC-CNT和Al-SiC-GNP复合材料。显微组织表征表明,与CNTs相比,GNPs在铝基体中的分散更加均匀。此外,还观察到SiC和GNP颗粒对位错的阻碍以及基体与增强材料之间的无缺陷界面。纳米压痕结果表明,与Al6061合金相比,Al-SiC-GNP和Al-SiC-CNT复合材料的表面纳米硬度分别显著提高约207%和27%,显微硬度分别提高了约36%和17%。摩擦学分析表明,Al-SiC-GNP复合材料的比磨损率降低约56%,而Al-SiC-CNT复合材料的比磨损率提高约122%。Al-SiC-GNP复合材料的高强度是由于在SiC存在下,GNPs会机械剥离成几层石墨烯(FLG)。此外,热失配、晶粒细化和Orowan循环等多种机制对复合材料的增强也有重要作用。而摩擦性能提升的主要原因是其表面挤出的GNP形成摩擦层,拉曼光谱和其他表征方法证实这一结果。

关键词：搅拌摩擦加工石墨烯碳纳米管复合材料磨损

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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

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Study of anisotropic variation of cosmic rays intensity with solar activity

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Natural Science 2011年第2期3卷 101-103页

作者： Chandra mani Tiwari Devendra sharma Lalji Tiwari Ajay Kumar Saxena Dadan Prasad Tiwari 不详

The annual average values of amplitudes and phases of first two harmonics of cosmic ray anisotropy have been derived by using the harmonic analysis technique for the period 1989 to 2004, which covers mostly the major period of solar cycles 22 and 23. In this paper we have taken the pressure corrected hourly data for Kiel neutron monitor station (cut off rigidity ≈ 2.29 GV) to derive the harmonic component of cosmic ray daily variation and compared with the data of Halekala neutron monitor (cut off rigidity ≈ 13.2 GV) for the period 1991 to 2004. From the analysis it has been concluded that the diurnal amplitude and phase of daily variation of cosmic rays have been found to be correlated with solar activity. However, the semi-diurnal amplitude and phase are inversely correlated with solar activity for both the stations.

关键词： Cosmic Ray Anisotropic Variation Solar Parameter

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Effect of Ferroelectric Nanopowder on Electrical and Acoustical Properties of Cholesteric Liquid Crystal

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Non-Metallic Material Science 2020年第1期2卷 12-16页

作者： Santosh mani Madhavi Pradhan Archana sharma SRChawade Sameer Hadkar Krishnakant Mishra Jyoti Amare Pradip Sarawade K.J.Somaiya College of Engineering Vidyavihar(E)Mumbai400077India Department of Physics University of MumbaiSantacruz(E)Mumbai400098India

The composite materials based on nanopowder dispersed liquid crystals are important both from fundamental research and device applications due to their unique properties such as improvement in various properties like electrical,optical,thermal,energy storage and spontaneous polarization etc.The proper selection of nanoparticle and its size which to be dispersed in particular liquid crystals is very important for a particular application.In the present study,a ferroelectric nanopowder of Barium Titanate(BaTiO3)was dispersed in cholesteric liquid crystal and the same was confirmed by Fourier Transform Infrared(FTIR)Spectroscopy.The various acoustical properties like ultrasonic velocity,density,Adiabatic Compressibility,Rao Constant,Wada Constant and Acoustic Impedance were investigated by ultrasonic interferometer at room temperature at fixed frequency.The dielectric constant was determined by Precision Impedance Analyzer.In addition to these investigations,particle size and surface area were also measured.Our investigation shows enhanced in dielectric and acoustical properties which may be useful for device applications extensively in microelectronics,low cost-photovoltaic devices,and custom-shaped containers possibly applied as a coating.

关键词： Ferroelectric nanopowder Cholesteric liquid crystal Dielectric Acoustical Ultrasonic

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Pre-harvest fruit bagging influences fruit color and quality of apple cv. Delicious

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Agricultural Sciences 2013年第9期4卷 443-448页

作者： Ram Roshan sharma Ram Krishna Pal Ram Asrey Vidya Ram Sagar Mast Ram Dhiman mani Ram Rana Division of Post Harvest Technology Indian Agricultural Research Institute New Delhi India IARI Regional Research Station Katrain India National Research Centre for Pomegranate Solapur India Pomologist and Fruit Grower Baragaon Kullu India

An attempt was made to observe the effect of pre-harvest bagging with spun-bound fabric bags on color and quality of Delicious apple. Bagging was done about a month before harvesting and removed 3-day before harvesting. Bagged and non-bagged fruits were stored at 2℃ ± 1℃ and 90%-95% RH. Observations were recorded on color and fruit quality attributes such as total phenolics, AOX activity, fruit Ca contents, LOX activity, SSC and ascorbic acid contents at harvest and during storage. Our studies have revealed that bagged fruits have better color development (Hunter “a” = 52) than non-bagged fruits at harvest (Hunter “a” = 38), which declined slightly during storage. Similarly, at harvest, bagged fruits contained high amounts of Ca (5.38 mg/100g) and total phenolics (9.3 mg GAE/100gpulp) exhibited higher AOX activity (12.6 μmoles Trolox g-1), and had better SSC and ascorbic acid contents than non-bagged fruits, and there was a decline in all recorded parameters during storage. Bagged fruits exhibited lower LOX activity (1.38 μmoles min-1 g-1 FW) at harvest than non-bagged fruits (2.14 μmoles min-1 g-1 FW), indicating that non-bagged fruits were more senescent than bagged fruits. Further, LOX activity increased during storage both in bagged and non-bagged apples but increase in LOX activity was slower in bagged apples than in non-bagged apples.

关键词： Apple Fruit Bagging Color Firmness LOX Activity AOX Activity Fruit Quality

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Acute Coronary Syndrome in a Young Male Secondary to Hyperhomocysteinemia

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World Journal of Cardiovascular Diseases 2020年第7期10卷 410-416页

作者： Kiran Prasad Acharya Chandra mani Adhikari Dipanker Prajapati Sachin Dhungel Amrit Bogati Mohamed Shaneez Najmy Pratima Poudel Deewakar sharma Department of Cardiology Shahid Gangalal National Heart Centre Kathmandu Nepal Department of Dermatology Kanti Children Hospital Kathmandu Nepal

Homocysteine is sulfur containing intermediary amino acid formed by the demethylation of dietary methionine to cysteine. The raised serum homocysteine level is one of the important risk factors associated with coronary artery disease. We present a 23-year-old male with no other risk factors of coronary artery disease presented to us with acute anterior wall myocardial infarction and was treated with primary percutaneous coronary intervention. During the routine work up post percutaneous coronary intervention significant elevation of serum homocysteine level was seen with markedly low serum vitamin B12 level and was treated for it along with standard therapy for acute myocardial infarction. The case illustrates the need to incorporate a plasma homocysteine level during work up of coronary artery disease especially in young patients, more importantly in those without any conventional risk factors.

关键词： Hyperhomocysteinemia Young Myocardial Infarction Risk Factors

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