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Understanding arsenic behavior in alluvial aquifers:Evidence from sediment geochemistry,solute chemistry and environmental isotopes

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Geoscience Frontiers 2024年第5期15卷 222-238页

作者： shailesh kumar Yadav AL.Ramanathan Chidambaram Sabarathinam Alok kumar Manoj kumar Anshula Dhiman School of Environmental Sciences Jawaharlal Nehru UniversityNew Delhi 110067India Water Research Center Kuwait Institute for Scientific ResearchKuwait Department of Environmental Studies University of Delhi110007India Department of Earth and Environmental Sciences Indian Institute of Science Education and Research MohaliSector 81140306India

The hydro-geochemistry and isotopic variations in groundwater,coupled with sediment geochemistry,were investigated in the Middle Gangetic Plain,India,to better understand the aquifer dynamics that influence the arsenic(As)evolution and ***-four groundwater samples,thirteen River water samples,and two sediment cores(33 mbgl)were *** samples were analyzed for major ions and trace metals,including As and stable isotopic variability(δ^(2)H,δ^(18)O,andδ^(13)C).The study area was categorized into older and younger alluvium based on existing geomorphological *** alluvium exhibits higher As enrichment in sediment and groundwater,ranging of 2.59–31.52 mg/kg and bdl to 0.62 mg/*** samples were thermodynamically more stable with As(OH)_(3)species ranging from 88.5%to 91.4%and FeOOH from 69%to 81%,*** and mineralogical analysis suggested goethite and siderite act as a source and sink for ***,statistical analysis suggested reductive dissolution as the primary mechanism for As mobilization in the study ***-temporal analysis revealed elevated concentrations of As in the central and northeastern regions of the study *** isotope(δ^(2)H andδ^(18)O)analysis inferred active recharge conditions primarily driven by *** depleted d-excess value and enrichedδ^(18)O in the groundwater of younger alluvium indicate the effect of groundwater recharge with significant evaporation *** recharge potentially decreased the quantity of arsenic in groundwater,whereas evaporation enrichment increased *** infiltration during recharge introduces oxygenated water into the aquifer,leading to changes in the redox conditions and facilitating biogeochemical *** carbon isotope(δ^(13)C)results suggest that high microbial activity in younger alluvium promotes As leaching from sediment into the groundwater.

关键词： Groundwater recharge Reductive dissolution Older alluvium Younger alluvium Ghazipur Stable isotope

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Emulsification of Indian heavy crude oil using a novel surfactant for pipeline transportation

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Petroleum Science 2017年第2期14卷 372-382页

作者： shailesh kumar Vikas Mahto Department of Petroleum Engineering Indian Institute of Technology (Indian School of Mines) Dhanbad Jharkhand India

The most economical way to overcome flow assurance problems associated with transportation of heavy crude oil through offshore pipelines is by emulsifying it with water in the presence of a suitable *** this research,a novel surfactant,tri-triethanolamine monosunflower ester,was synthesized in the laboratory by extracting fatty acids present in sunflower（Helianthus annuus）*** surfactant was used to prepare oil-in-water emulsions of a heavy crude oil from the western oil field of *** emulsification,a dramatic decrease in pour point as well as viscosity was *** the prepared emulsions were found to be flowing even at 1°*** emulsion developed with 60%oil content and 2wt%surfactant showed a decrease in viscosity of 96%.The stability of the emulsion was investigated at different temperatures,and it was found to be highly *** effectiveness of surfactant in emulsifying the heavy oil in water was investigated by measuring the equilibrium interfacial tension（IFT）between the crude oil（diluted）and the aqueous phase along with zeta potential of emulsions.2wt%surfactant decreased IFT by almost nine times that of no *** results suggested that the synthesized surfactant may be used to prepare a stable oil-in-water emulsion for its transportation through offshore pipelines efficiently.

关键词： Heavy crude oil Oil-in-water emulsion Pipeline transportation Sunflower oil Rheology Stability

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Potential groundwater recharge zones within New Zealand

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Geoscience Frontiers 2019年第3期10卷 1065-1072页

作者： shailesh kumar Singh Malte Zeddies Ude Shankar George A.Griffiths National Institute of Water and Atmospheric Research

Water resources in New Zealand are not evenly distributed across the country which makes it difficult to adequately allocate the use of water resources in every basin. Groundwater is a fundamental water resource in New Zealand for agricultural, industrial and domestic use. Detailed knowledge regarding groundwater recharge potential is a pre-requisite for sustainable groundwater management, including the assessment of its vulnerability to contamination by pollutants. In this study, a comprehensive GIS approach was used to map the potential groundwater recharge zones across New Zealand. National data sets of lithology, slope, aspect, land use, soil drainage and drainage density were converted to raster data sets with a spatial resolution of 500 m x 500 m and superimposed to derive groundwater potential zones. The resultant maps demonstrate that the potential is low in urban and mountainous areas, such as the Southern Alps, whereas the highest potential can be found in regions with large lakes and in the lower elevation plains areas, where Quaternary sediments prevail. The resulting maps can be used to identify areas of high nutrient leaching in zones where high groundwater recharge potential exists.

关键词： GIS Potential groundwater recharge map New Zealand

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Sorghum germplasm from West and Gentral Africa maintained in the ICRISAT genebank: Status,gaps,and diversity

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The Crop Journal 2017年第6期5卷 518-532页

作者： Hari Deo Upadhyaya Kothapally Narsimha Reddy Mani Vetriventhan Mohammed Irshad Ahmed Gumma Murali Krishna Mulinti Thimma Reddy shailesh kumar Singh Genebank International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) Patancheru 502324 Telangana India Department of Agronomy Kansas State University Manhattan KS 66506 USA The UWA Institute of Agriculture The University of Western Australia Crawley WA 6009 Australia Remote Sensing and GIS Unit International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) Patancheru 502324Telangana India

The genebank at ICRISAT maintains 8020 accessions of sorghum from 16 West and Central African countries. Geographical gaps and diversity were assessed in the collection. Using the passport data of 3991 accessions for which georeferenced data were available, a total of386 districts(gaps) located in 11 West and Central African countries were identified as geographical gaps. Burkina Faso with 140 and Nigeria with 118 districts were identified as countries with major geographical gaps. The collection of 43 accessions of wild species represented only three species belonging to Sorghum bicolor ssp. drummondii and ***, S. hevisonii, and S. macrochaeta, highlighting the need for collection missions aimed exclusively at enriching the collection of wild relatives. Accessions having characterization data(7630) were used to assess diversity. The first three principal components contributed to >60% of variation. Maximum diversity was observed in the collection from Nigeria for both qualitative and quantitative traits. Mean values indicated significant differences between basic and intermediate races for the traits studied. Among the races, accessions of guinea-caudatum for qualitative traits and those of caudatum for quantitative traits were highly diverse. The low intensity of the sorghum collection and the many geographical gaps in the collection underline the importance of launching collection missions to fill the gaps, particularly in regions of predominantly guinea *** of possible duplicate accessions is needed to identify duplicates in the collection. It is suggested that all passport information including georeferenced data of collection sites should be collected when samples are collected in gaps.

关键词： Collection Diversity Gaps Germplasm Landraces Sorghum

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Fatty Acid Compositional Studies of Lesser Known <i>Acacia tortilis</i>Seed Oil

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Food and Nutrition Sciences 2013年第9期4卷 59-62页

作者： Manjoosha Srivastava shailesh kumar Dayanand Dinanath College Institute of Pharmacy Kanpur India. Phytochemistry Division CSIR-National Botanical Research Institute Lucknow India

A. tortilis is commonly known as “Israeli babool”. The species is exposed to the world for its pods, gum and other aerial parts as fodder &feed for cattles. The plant was used as antidiabetic, antidiarrhoeal, antiasthmatic and also had several other medicinal benefits but the seed oil was not explored to the extent of its real potential. Hence the study was carried out to characterize the seed for oil and analysis of fatty acid composition through GC for quality control and maintenance. Commercial indices of oil were also estimated. Extracted oil is rich in Linolenic acid (50.43%) and Linoleic acid (36.74%). Beside this palmitic, stearic and oleic acid are other fatty acids identified. MUFA, PUFA, SFA and omega-6/ omega-3 ratio were also found to be promising for its potentiality in edible and clinical uses. The investigation thus scopes the utility of oil and prospects the lesser known plant seed as alternative oil source of nutritional and therapeutic importance.

关键词： A. tortilis Seed Oil Fatty Acid Cholesterol Fat

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Evaluation,partial characterization and purification of acetylcholine esterase enzyme and antiangiogenic activity from marine sponges

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Journal of Coastal Life Medicine 2014年第11期 849-854页

作者： Maushmi shailesh kumar Sukanya Gopalkrishnan Department of Pharmaceutical Biotechnology Shobhaben Pratapbhai Patel School of Pharmacy and Technology ManagementSVKM’S NMIMSVile Parle westMumbai-400056India

Objective:To test three marine sponges Halichondria glabrata Keller,1891;Spirastrellapachyspira(***)Levi,1958 and Cliona lobata Hancock,1849 for the presence of the acetylcholinesterase(AChE)in both young and developed samples from western coastal area of *** methanolic extract was selected for anti/pro angiogenic ***:They were evaluated for AChE activity using Ellman’s assay based on production of yellow colored *** of the enzyme was planned using ammonium sulphate precipitation and characterization by sodium dodecyl sulfate polyacrylamide gel *** membrane(ChAM)assay model was used for angiogenic/antiangiogenic ***:All the three sponges showed good specific enzyme activity and *** contained maximum specific enzyme *** percent of ammonium sulphate precipitation of crude protein sample gave single band at 66 kDa corresponding to the true *** assay was performed at 62.5,125.0 and 250.0μg/*** beyond 250μg/mL extract showed toxic response with anti angiogenic activity at all the ***:AChE activity was detected in all *** showed good anti-angiogenic response at 62.5μg/*** was highly toxic affecting microvasculature of ChAM as well as normal growth and development of the embryo at 500μg/*** further characterization of bioactive compounds from the extract of ***,the compounds can be developed for anti tumor activity.

关键词： Halichondria glabrata Keller Spirastrella pachyspira Levi Cliona lobata Hancock Acetylcholinesterase Chorioallantoic membrane Antiangiogenic activity Sodium dodecyl sulfate polyacrylamide gel electrophoresis

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A SUSPENSION MODEL FOR BLOOD FLOW THROUGH A CATHETERIZED ARTERY

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International Journal of Biomathematics 2012年第5期5卷 21-35页

作者： shailesh MISHRA NARENDRA kumar VERMA S. U. SIDDIQUI Department of MathematicsHarcourt Butler Technological Institute Kanpur-208002 India

The present work is concerned with the analysis of an axi-symmetric flow of blood through coaxial tubes where the outer tube has an axially symmetric mild stenosis and the inner tube has a balloon which is axi-symmetric in nature. The mild stenosis approximation is used to solve the present problem. The effect of the volume fraction density of the particles, the maximum height attained by the balloon, the radius of the inner tube, which keeps the balloon in position k, and the axial displacement of the balloon have been studied. Flow parameters such as the resistive impedance, the wall shear stress distribution in the stenotic region and its magnitude at the stenosis throat have been computed for different parameters. It is observed that the resistance to flow decreases with increasing values of the axial displacement of the balloon, while the resistance to flow increases with the volume fraction density of the particles, the radius of the inner tube, which keeps the balloon in position k, and the maximum height attained by the balloon. The wall shear stress distribution in the stenotic region possesses a character similar to the resistance to flow with respect to any parameter.

关键词： Blood now stenosis resistive impedance wall shear stress suspension.

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On-chip excitation of single germanium vacancies in nanodiamonds embedded in plasmonic waveguides

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Light(Science & Applications) 2018年第1期7卷 446-454页

作者： Hamidreza Siampour shailesh kumar Valery A.Davydov Liudmila F.Kulikova Viatcheslav N.Agafonov Sergey I.Bozhevolnyi Centre for Nano Optics University of Southern DenmarkCampusvej 55Odense M DK-5230Denmark L.F.Vereshchagin Institute for High Pressure Physics Russian Academy of SciencesTroitskMoscow 142190Russia GREMAN Universitéde ToursUMR CNRS CEA 615737200 ToursFrance

Monolithic integration of quantum emitters in nanoscale plasmonic circuitry requires low-loss plasmonic configurations capable of confining light well below the diffraction *** demonstrated on-chip remote excitation of nanodiamond-embedded single quantum emitters by plasmonic modes of dielectric ridges atop colloidal silver *** nanodiamonds were produced to incorporate single germanium-vacancy(GeV)centres,providing bright,spectrally narrow and stable single-photon sources suitable for highly integrated *** electron-beam lithography with hydrogen silsesquioxane(HSQ)resist,dielectric-loaded surface plasmon polariton waveguides(DLSPPWs)were fabricated on single crystalline silver plates to contain those of deposited nanodiamonds that are found to feature appropriate single GeV *** low-loss plasmonic configuration enabled the 532-nm pump laser light to propagate on-chip in the DLSPPW and reach to an embedded nanodiamond where a single GeV centre was *** remote GeV emitter was thereby excited and coupled to spatially confined DLSPPW modes with an outstanding figure-of-merit of 180 due to a~six-fold Purcell enhancement,~56%coupling efficiency and~33μm transmission length,thereby opening new avenues for the implementation of nanoscale functional quantum devices.

关键词： excitation silver thereby

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药用金钮扣属植物研究综述(英文)

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中西医结合学报 2011年第11期9卷 1170-1178页

作者： Kishan Lal Tiwari shailesh kumar Jadhav Veenu Joshi School of Studies in Biotechnology Pt.Ravishankar Shukla UniversityRaipurChhattisgarh 492010India

植物药在人类的医学实践中已有上千年的应用历史,特别是在亚洲的一些国家,植物药用资源被认为是一种可以随时取用的宝贵的医疗保健资源。印度拥有众多种类的药用植物,然而,其中很大一部分传统药用植物并没有被开发使用或未被现代医学科... 详细信息

植物药在人类的医学实践中已有上千年的应用历史,特别是在亚洲的一些国家,植物药用资源被认为是一种可以随时取用的宝贵的医疗保健资源。印度拥有众多种类的药用植物,然而,其中很大一部分传统药用植物并没有被开发使用或未被现代医学科学研究证明其功效。因此,目前很有必要开发传统药用植物并使其最大限度地造福人类。本篇综述总结报道了一种很有潜力的药用植物即金钮扣属植物。过去几年中,很多从这类植物中提取的新化合物及其功效已经得到证实,因此本文旨在总结最新的有关金钮扣属植物的植物化学及民族药物学应用、药理学作用及物种保护方法的科学研究报道。

关键词：金钮扣属植物提取物千日菊素医学传统植物药综述

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Mathematical Modeling of Diffusion Phenomenon in a Moderately Constricted Geometry

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Applied Mathematics 2011年第2期2卷 241-246页

作者： shailesh Mishra Narendra kumar Verma Shafi Ullah Siddiqui 不详

The incorporation of fluid flow through modelled normal and stenosed capillary-tissue exchange system has highlighted issues that may have major applications for the study of diffusion phenomenon. Results clearly demonstrate the important roles played by various physiological characteristics and diffusion variables involved in the analysis on blood flow. Assessment of the severity of the disease could be made possible through the variation of a parameter named as retention parameter. An attempt has been made to study the effects of local variation of viscosity on flow, wall-shearing stress and distribution of dissolved material in diseased artery as compared to the normal.

关键词： Stenosis Diffusion Wall Shear Stress Viscosity Retention Parameter

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