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Status,structure and environmental variations in semi-arid mangroves of India

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Journal of Forestry Research 2020年第1期31卷 163-173页

作者： G.A.Thivakaran Seema b.sharma Abhiroop Chowdhury Arumugam Murugan Coastal and Marine Ecology Division Gujarat Institute of Desert EcologyBhujGujaratIndia Department of Earth and Environmental Sciences KSKV Kachchh UniversityMundra RoadBhujGujaratIndia Department of Chemistry Manipal University JaipurDehmi KalanJaipur-Ajmer Express WayJaipurRajasthan 303007India Central Marine Fisheries Research Institute Mandapam Regional CentreMarine Fisheries P.OMandapam CampusRamanathapuramTamil Nadu 623520India

The semi-arid mangroves of the Gulf of Kachchh,the largest ecosystems on the west coast of India,are poorly studied in terms of vegetation structure and environmental parameters in spite of their conservation ***,it is necessary to document the structural features of these mangroves in view of ongoing coastal industrial *** forest structure in 10 locations on the northern and southern coasts of the Gulf of Kachchh were assessed using the line intercept transect *** included density of young and mature age classes,tree heights,diameters at breast height(DbH)and aboveground biomass,along with seven significant environmental *** tree densities ranged from 350 to 1567 ***-1,while average height and girth at breast height ranged from 1.0 to 6.8 m and 3.0 to 137.0 cm,*** majority of trees(55.6%)were in b 1.8 m height class followed by a 1.9 to 2.4 m class(25.1%).DbH was most often in class 2 cm or lower than *** the canopy index classes,more trees were recorded in class ≤2 *** regeneration density was greater than the recruitment *** study indicates that the poor structural attributes of Avicennia marina *** Stapf and Mold dominated mangroves are largely due to aridity induced by scarce and erratic rainfall and high soil and water *** results should be valuable in conserving and sustainably managing these mangroves in the face of developmental activities.

关键词： Mangroves Vegetation structure Abiotic factors biodiversity Forest management Aboveground biomass Conservation

Sub-acute Toxicity of Carbofuran on Acetylcholinesterase Activity in the Freshwater Catfish,Clarias batrachus

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环境与职业医学 2005年第5期22卷 403-407页

作者： Rajendra K.Singh b.sharma Laboratory of biochemical Toxicology Department of biochemistry Dr.R.M.L.Avadh UniversityFaizabad-224 001INDIA

The inhibition of acetylcholinesterase (ACHE) activity has been widely used as a biomarker in an animal exposed to the pesticides. However, the interaction of extensively used organocarbamate insecticide, carbofuran, with the nervous system of the aquatic organisms is not properly studied. AChE is a key enzyme which catalyses the hydrolysis of acetylcholine, a neurotransmitter at the neuromuscular junctions, and thus regulates the neurotransmission system. In the present study, we have evaluated the impact of sub-acute concentrations (0.01 and 0.02 mg/L i.e. 1/20th and 1/10th of LC50) of carbofuran on the activity of acetylcholinesterase,from different tissues of Clarias batrachus, a fresh water teleost, after 96 hr and 15 days exposure periods in vivo. The carbofuran significantly reduced the activity of AChE in different tissues of C. batrachus at both concentrations and periods of exposure. The greater inhibition of AChE activities were recorded in fish tissues at higher carbofuran concentration (0.02 mg/L) after longer (15days) treatment period. The inhibition of AChE activity in all fish tissues tested was dependent on pesticide concentration and the duration of treatment. AChE from the tissues of C. batrachus was found to be a true cholinesterase as it was completely inhibited by the small concentration (nM) of eserine as tested in vitro. It was found that carbofuran at very low concentration exerted significant inhibitory effect on AChE activity in fish tissues.

关键词：急性中毒乙酰胆碱酯酶酶活性淡水鱼环境卫生

Tribological characteristics of friction stir processed graphite and tin/LM24 surface composites

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Friction 2021年第3期9卷 569-582页

作者： Vipin sharma Ujjwal PRAKASH b.Venkata MANOJ KUMAR Department of Metallurgical and Materials Engineering Indian Institute of Technology RoorkeeRoorkee 247667India

Friction stir processing(FSP)is an emerging solid-state technique for preparing surface composites using various *** and metallic particles are easily reinforced in a matrix by this *** composites made from an LM24 alloy reinforced with graphite and tin,with good wettability and material flow owing to the low melting point of tin,were fabricated by FSP at two rotational speeds of 1,400 and 1,000 *** its low hardness,the graphite/LM24 surface composite fabricated at a higher rotational speed of 1,400 rpm exhibited better wear ***,its frictional behavior was not significantly affected by the *** fabricated surface composites with graphite and tin reinforcement as well as graphite-only reinforcement exhibited contradicting behaviors under sliding wear *** post wear analysis indicated that abrasion,adhesion,layer formation,and delamination occurred on the composite surfaces.

关键词： composites friction stir processing graphite tin Al-Si alloy wear

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开展机构协作发展远程教育

中国远程教育 2004年第04S期 29-32页

作者： Chandra b.sharma Sohanvir S.Chaudhary 肖俊洪汕头广播电视大学

本文原文发表于“学习联邦”(CommonwealthofLearning)网站《知识系列》(KnowledgeSeries)栏目(2003年)。学习联邦是英联邦各成员国的政府首脑倡议成立的政府间组织,其宗旨是鼓励开发和共享开放学习和远程教育的知识、资源和技术。目前... 详细信息

本文原文发表于“学习联邦”(CommonwealthofLearning)网站《知识系列》(KnowledgeSeries)栏目(2003年)。学习联邦是英联邦各成员国的政府首脑倡议成立的政府间组织,其宗旨是鼓励开发和共享开放学习和远程教育的知识、资源和技术。目前我国远程教育机构也正在开展各种形式的协作,既有电大之间的协作,也有电大与其他教育机构的协作,还有国际间的协作,但毕竟一切刚刚起步许多地方有待于进一步完善。因此,我们认为这篇经验之谈的文章所提出的一些原则、建议、指南等对我们有一定指导意义和借鉴价值。现将其译成中文,以飨读者,并向印度甘地国立开放大学sharma高级讲师和Chaudhary教授以及学习联邦组织致谢!

关键词：机构协作远程教育资源共享教育政策评估标准

Combined effects of Joule heating and nonuniform heat source/sink on unsteady MHD mixed convective flow over a vertical stretching surface embedded in a Darcy-Forchheimer porous medium

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Propulsion and Power Research 2022年第2期11卷 276-292页

作者： b.K.sharma Rishu Gandhi Department of Mathematics Birla Institute of Technology and SciencePilani333031RajasthanIndia

This paper deals with an unsteady magnetohydrodynamics(MHD)heat and masstransfer for a viscous incompressible fluid through a vertical stretching surface embedded ina Darcy-Forchheimer porous medium in the presence of a non-uniform heat source/sink andfirst-order chemical *** porous surface is subjected to a uniform transverse *** influence of velocity,thermal,and concentration slip is also *** governing equations are coupled non-linear partial differential equations,which have been converted via similarity transformation into a set of ordinary differential *** resultantsystem of non-linear ordinary differential equations has been solved numerically with the helpof the“MATLAb”bVP4C *** are presented graphically to analyze the effects ofvarious physical parameters discovered in the problem such as Hartmann number(M),Forchheimer number(Fr),Grashof number(Gr),solutal Grashof number(Gc),suction parameter(S),porosity parameter(el),dimensionless velocity slip(Sv),Prandtl number(Pr),dimensionless thermal slip(St),space-dependent heat source/sink parameter(eA1),temperature-dependent heat source/sink(eb)1),Eckert number(Ec),Schmidt number(Sc),chemical reaction parameter(g),unsteadiness parameter(A),and dimensionless concentration slip(Sc)on non-dimensionalvelocity ec0ðhÞ,temperature zðhÞ,and concentration efðhÞ*** influence of these parameters on skin-friction coefficient(C)f),Nusselt number(Nu)x),and Sherwood number(Sh)x)areexpressed in tabular *** is observed that an enhancement in Fr and el results in the declination of the velocity *** is an enhancement in temperature with an increment in theeA)1 and eb)*** physical representation of flow characteristics that appeared in the problem ispresented using various graphs to depict real-world applications in industrial and *** results were compared to previous studies,revealing that the two are in *** nov

关键词： Magnetohydrodynamics(MHD) Unsteady Heat and mass transfer Non-Darcian porous medium Heat source Joule effect

bioprospection of marine actinomycetes: recent advances,challenges and future perspectives

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Acta Oceanologica Sinica 2019年第6期38卷 1-17页

作者： Swati sharma Abhay b. Fulke Asha Chaubey CSIR-Indian Institute of Integrative Medicine (CSIR-IIIM) CSIR-Innovation CentreMumbai 400053India Regional Centre CSIR-National Institute of Oceanography (CSIR-NIO)Mumbai 400053India CSIR-Indian Institute of Integrative Medicine Jammu180001India

In exploring new sources for economically important products, marine environment draws particular attention because of its remarkable diversity and extreme conditions;it is known to produce metabolic products of great value. It represents untapped source for the discovery of novel secondary metabolites with varying potential such as antibiotic, anti-tumor, antifouling and cytotoxic properties. Marine actinomycetes distributed throughout the marine environment from shallow to deep sea sediments have proved to be a finest source for this discovery. Secondary metabolites derived from marine actinomycetes have proved their worth in industries based on the research on their properties and wide range applications. Spotlight of the review is range of marine based actinomycetes products and significant research in this field. This shows the capability of marine actinomycetes as bioactive metabolite producers. Additionally, the present review addresses some effective and novel approaches of procuring marine microbial compounds utilizing the latest screening strategies of drug discovery from which traditional resources such as marine actinobacteria has decreased due to declining yields. The aim is in the context of promoting fruitful and profitable results in the near future. The recent surfacing of new technologies for bioprospection of marine actinomycetes are very promising, resulting in high quality value added products, and will be de?ning a new era for bioactive compounds with medical and biotechnological applications.

关键词： marine actinomycetes bioprospection commercial use bioactive compounds genome mining

Microstructures of co-axially folded vein segments and crenulation cleavage： Evidence for dissolution phenomena in the Chamba Thrust Sheet, western Himalayas

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Episodes 2004年第2期27卷 119-124页

作者： b.K.sharma A.M.bhola DepartmentofGeology UniversityofDelhiDelhi-110007India.

The metasediments in the Chamba region experienced three phases of deformation: DF1, DF2 and *** quartz veins are co-folded with the F2 crenulation folds. Their geometric and tectonic significance is studied by microstructures and shortening adjacent to the discrete crenulation cleavage, S2. Microstructures of folded vein segments, their geometric changes and truncation to cleavage (S2) are mainly due to pressure-solution phenomena and the estimated volume loss from reconstructed vein segments range from 16 to 25.5%,which is closely related to volume decrease (26%) calculated from the polydeformed slates of North Wales areas.

关键词：显微结构变质沉积物地质学石英纹理

Mathematical model of micropolar fluid in two-phase immiscible fluid flow through porous channel

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Applied Mathematics and Mechanics(English Edition) 2018年第7期39卷 993-1006页

作者： P.K.YADAV S.JAISWAL b.D.sharma Department of Mathematics Motilal Nehru National Institute of Technology Allahabad

This paper is concerned with the flow of two immiscible fluids through a porous horizontal channel. The fluid in the upper region is the micropolar fluid/the Eringen fluid, and the fluid in the lower region is the Newtonian viscous fluid. The flow is driven by a constant pressure gradient. The presence of micropolar fluids introduces additional rotational parameters. Also, the porous material considered in both regions has two different permeabilities. A direct method is used to obtain the analytical solu- tion of the concerned problem. In the present problem, the effects of the couple stress, the micropolarity parameter, the viscosity ratio, and the permeability on the velocity profile and the microrotational velocity are discussed. It is found that all the physical parameters play an important role in controlling the translational velocity profile and the microrotational velocity. In addition, numerical values of the different flow parameters are computed. The effects of the different flow parameters on the flow rate and the wall shear stress are also discussed graphically.

关键词： micropolar fluid immiscible fluid porous medium couple stress microp=olarity parameter

Tribology of WC reinforced SiC ceramics: Influence of counterbody

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Friction 2019年第2期7卷 129-142页

作者： Sandan Kumar sharma b.Venkata MANOJ KUMAR Young-Wook KIM Department of Metallurgical and Materials Engineering Indian Institute of Technology (IIT) Roorkee TriboCeramics Laboratory Department of Materials Science and Engineeringthe University of Seoul

Hot pressed silicon carbide(SiC) composites prepared with 0, 10, 30 or 50 wt% tungsten carbide(WC) are subjected to dry sliding wear against WC-Co and steel ball. In particular an attempt has been made to answer the following important questions:(i) How does the load(from 5 to 20 N) effect sliding wear behaviour of SiC-ceramics against WC-Co and steel counterbodies?(ii) Is there any effect of WC content on friction and wear characteristics of SiC ceramics?(iii) Does the dominant material removal mechanism of SiC ceramics change with the addition of WC or counterbody?(iv) What is the influence of mechanical properties on the sliding wear? Experimental results indicated that coefficient of friction(COF) for the SiC ceramics varied between 0.66 and 0.33 with change in load and counterbodies. Wear volume for SiC ceramics found approximately 6-10 times more against WC-Co as compared against steel. Wear volume changes from 2.0 × 10^(–3)mm^3 to 1.2 × 10^(–2)mm^3 with change in counterbodies for SiC -(10, 30 or 50 wt%) WC composite at 20 N. SiC ceramics indicated abrasion and composites reveal tribochemical wear as major material removal mechanisms. Wear is influenced by the hardness of counterbody and fracture toughness of SiC -WC composites.

关键词： silicon carbide tungsten carbide composites steel sliding wear counterbody