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A Study of Extra-auditory Effects of Noise

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Biomedical and Environmental Sciences 1994年第1期7卷 35-40页

作者： A.k. SRIvASTAvA B.N. GUPTAl v. BIHARI N. MATHUR P. kUMAR R.P. sharma AND S.k. BHARGAvA(Industrial Toxicology Research Centre, P BNo. 80, MG.Marg,Lucknow- 226 001, Indta) To whom corresrmdence should be addressed. Industrial Toxicology Research Centre Lucknow India.

Paper mill workers (106) exposed to noise ranging from 80 to 96 dBA were assessed foralteration in clinical status. Neurobehavioral functions were examined with the help of aquestionnaire. The study did not reveal any... 详细信息

关键词： A Study of Extra-auditory Effects of Noise

Environmentally assisted cracking resistance of Al-Cu-Li alloy AA2195 using slow strain rate test in 3.5% NaCl solution

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Transactions of Nonferrous Metals Society of China 2017年第2期27卷 241-249页

作者： R.GHOSH A.vENUGOPAL P.RAMESH NARAYANAN S.C.sharma P.v.vENkITAkRISHNAN Materials and Metallurgy Group Materials and Mechanical EntityVikram Sarabhai Space CentreThiruvananthapuram-695022KeralaIndia

The general corrosion and environmental cracking resistances of Al-Cu-Li alloy AA2195 were investigated in 3.5% NaCl environment and compared with those of another high strength alloy AA2219. The general corrosion resistance of these alloys was examined using immersion corrosion and potentiodynamic polarization tests, while the stress corrosion cracking （SCC） resistance was evaluated by slow strain rate test （SSRT） method. The tested samples were further characterized by SEM-EDS and optical profilometry to study the change in corrosion morphology, elemental content and depth of corrosion attack. The reduction in ductility was used as a parameter to evaluate the SCC susceptibility of the alloys. The results indicated that the corrosion resistance of AA2195 alloy was better than that of AA2219 alloy as it exhibited lower corrosion rate, along with lower pit depth and density. However, the SCC index （εNaCl/εair） measured was greater than 0.90, indicating good environmental cracking resistance of both the alloys. Detailed fractography of the failed samples under SEM？EDS, in general, revealed a typical ductile cracking morphology for both the alloys.

关键词： Al-Cu-Li alloy stress corrosion cracking fractography potentiodynamic polarization

Ecological Consequences of Land Use Change: Forest Structure and Regeneration across the Forest-grassland Ecotone in Mountain Pastures in Nepal

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Journal of Mountain Science 2014年第4期11卷 838-849页

作者： Lila Nath sharma Ole Reidar vETAAS Ram Prasad CHAUDHARY Inger Elisabeth MREN Department of Geography University of Bergen Bergen 5020 Norway Research Centre for Applied Science and Technology and Central Department of Botany Tribhuvan UniversityKathmandu 977 Nepal

The ecotone, the spatial transition zone between two vegetation communities, is claimed to have more species than the adjoining communities. However, empirical studies do not always confirm higher richness at the ecotone. The ecotone position and structure are dynamic over time and space and it is driven by the changes in climate, land use or their interaction. In this context, we assessed the forest- grassland ecotone of temperate mountains in central Nepal by i） comparing species composition and richness across the ecotone, ii） analyzing if the forestgrassland ecotone is shifting towards the grassland center by colonizing them with trees, and iii） discussing the consequence of changed disturbance regime in the dynamics of this ecotone and the surrounding grasslands. We analyzed vegetation data sampled from belt transects laid across the forest- grassland ecotone in semi-natural grassland patches. vegetation data consisting of species richness and composition, and size structure and regeneration of the two most dominant tree species, namely Rhododendron arboreum and Abies spectabilis, from the transects, were used to analyze the trend of the forest-grassland ecotone. Forest and grasslands were different in terms of floristic composition and diversity. vascular plant speciesrichness linearly increased while moving from forest interior to grassland center. Spatial pattern of tree size structure and regeneration infers that forest boundary is advancing towards the grasslands at the expense of the grassland area, and tree establishment in the grasslands is part of a suceessional process. Temporally, tree establishment in grasslands started following the gradual decline in disturbance. We argue that local processes in terms of changed land use may best explain the phenomenon of ecotone shift and consequent forest expansion in these grasslands. We underpin the need for further research on the mechanism, rate and spatial extent of ecotone shift by using advaneed tools to

关键词： Ecotone shift Grasslands Forest Landuse change Rhododendron

Numerical Analysis of Stresses on Layer-by-Layer Basis in FML Composite Cylinder Subjected to External Hydrostatic Loading

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Materials Sciences and Applications 2015年第6期6卷 489-499页

作者： B. G. Sumana H. N. vidya Sagar k. v. sharma M. krishna Research Scholar Department of Mechanical Engineering University Visvesvaraya College of Engineering Bangalore India Department of Mechanical Engineering University Visvesvaraya College of Engineering Bangalore India Department of Mechanical Engineering R V College of Engineering Bangalore India

The aim of the research work was to numerically investigate the residual stresses induced between the layers of fiber metal laminate (FML) cylinder (glass/epoxy reinforced aluminum laminates) under buckling hydrostatic loading. For the analysis of buckling behavior of FML cylinders, various fiber orientations such as 0/90°, 60/30°, ±45° and ±55° and different FRP thickness of 1, 2, and 3 mm were considered. The aluminum cylinder of inner diameter 80 mm, length 800 mm and wall thickness 1 mm was modeled with SHELL281 element type and a total of 1033 elements were used for computing the induced residual stresses between the layers. The results show that magnitude of residual stresses between the layers decreased along the thickness from outer layer towards the inner layer in sine wave form. The maximum residual von-Mises stress was at inner aluminum layer while the maximum residual radial stress was at the outermost layer of FML cylinder due to the inward pressure. Among all types of FML cylinder 0/90° fiber oriented FML cylinder exhibited the least radial stress and a maximum von-Mises stress along the FRP thickness.

关键词： FML Cylinder External Hydrostatic Loading Residual Stress von-Mises Stress Radial Stress

Fracture Toughness of Cast Al-Zn-Mg Alloys

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Journal of Materials Science & Technology 1996年第3期12卷 199-202页

作者： k.H. W.Seah(Dept. of Mech. Eng., National University of Singapore, Singapore 0511)S. C. sharma (To whom correspondence should be addressed)(Dept. of Mech. Eng., R.v.College of Engineering, Bangalore-560-059, karnataka, India) Rv COLL ENGN DEPT MECH ENGN BANGALORE 560059 KARNATAKA INDIA

Compact tension specimens of as-cast Al-3Zn-2Mg and Al-7Zn-2Mg (in wt pct) alloys were subjected to fracture toughness tests at room temperature according to specification5 laid down in ASTM E-399-81. It was found that increasing the Zn content, grain refinement and increasing the solidification rate lead to an increase in the fracture toughness of the material.

关键词： Zn Fracture Toughness of Cast Al-Zn-Mg Alloys Al Cast

A Review on Mechanical Properties of Natural Fiber Reinforced Hybrid Polymer Composites

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Journal of Minerals and Materials Characterization and Engineering 2015年第5期3卷 420-426页

作者： k. P. Ashik Ramesh S. sharma R & D Center Department of Mechanical Engineering R.V. College of Engineering Bangalore India

Natural fibres will take a major role in the emerging “green” economy based on energy efficiency, the use of renewable materials in polymer products, industrial processes that reduce carbon emissions and recyclable materials that minimize waste. Natural fibres are a kind of renewable resources, which have been renewed by nature and human ingenuity for thousands of years. They are also carbon neutral;they absorb the equal amount of carbon dioxide they produce. These fibers are completely renewable, environmental friendly, high specific strength, non-abrasive, low cost, and bio-degradability. Due to these characteristics, natural fibers have recently become attractive to researchers and scientists as an alternative method for fibers reinforced composites. This review paper summarized the history of natural fibers and its applications. Also, this paper focused on different properties of natural fibers (such as hemp, jute, bamboo and sisal) and its applications which were used to substitute glass fiber.

关键词： Natural Fiber Polymer Carbon Bio Degradability Human

A neutronic experiment to support the design of an Indian TBM shield module for ITER

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Plasma Science and Technology 2019年第6期21卷 147-152页

作者： H L SWAMI M ABHANGI Sanchit sharma S TIWARI A N MISTRY v vASAvA v MEHTA S vALA C DANANI v CHAUDHARI P CHAUDHURI Institute for Plasma Research Gandhinagar Gujarat 382428 India Homi Bhabha National Institute(HBNI) Anushaktinagar Mumbai 400094 India Pandit Deendayal Petroleum University Gandhinagar Gujarat 382007 India

A shield module is associated with an Indian Test Blanket Module (TBM) in ITER to limit the radiation doses in port inter-space *** shield module is made of stainless steel plates and water *** is identified as an important component for radiation protection because of its radiation exposure control *** radiation protection classification leads to more assurance of the component *** order to validate and verify the design of the shield module,a neutronic laboratory-scale experiment is designed and *** experiment is planned by considering the irradiation under a neutron source of 14 Mev and yields of 1010 n *** reference neutron spectrum of the ITER TBM shield module has been achieved through optimization of the neutron source spectrum by a combination of steel and lead *** neutron spectrum and flux are measured using a multiple foil activation technique and neutron dose-rate meter LB 6411 (He-3 proton recoil counter with polyethylene),*** neutronic design simulation is assessed using MCNP5 and FENDL 2.1 crosssection *** paper covers neutronic design,irradiation and the outcome of the experiment in detail.

关键词： TBM shield module neutronic experiment ITER MCNP neutron attenuation

CFOA Based Band Pass and Band Stop Ladder Filter—A New Configuration

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Circuits and Systems 2016年第1期7卷 29-42页

作者： Praween k. Sinha Neelam sharma Simran Agarwal Sudipto Saha Electronics and Communication Department Maharaja Agrasen Institute of Technology New Delhi India

A new technique for the conversion of ladder based filter into CFOA based filter has been proposed. The technique uses signal flow graph and converts the existing LC ladder based filter into band pass & band stop configurations. The design of band pass and band stop filter has been realized using the proposed technique. The proposed configuration is implemented using CFOA as an active device and all the capacitors are grounded. CFOA based circuits have greater linearity, high dynamic rate, high slew rate and high signal bandwidth. Simulation has been carried out using simulation software P Spice (v10.1). The simulation results have been demonstrated and discussed.

关键词： CFOA-Current Feedback Operational Amplifier Ladder Filter Signal Flow Graph Current Mode voltage Mode Band Pass Filter Band Stop Filter

Electrochemical Impedance Spectroscopy of Hybrid Epoxy Resin Emulsion Coatings

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Journal of Minerals and Materials Characterization and Engineering 2012年第10期11卷 1012-1019页

作者： Rakesh N. Patil Brihbihari v. sharma Prakash A. Mahanwar Department of Polymer & Surface Engineering Institute of Chemical Technology Mumbai India

A hybrid epoxy resin one pack emulsion with acrylate was synthesized for application in the field of corrosion protec- tion. Electrochemical impedance tests were applied to steel specimens coated with hybrid epoxy and tested after im- mersion in 3.5% NaCl solution at room temperature. Results taken from Nyquist and Bode plots as were analyzed by means of software provided with the instrument. Specimens were examined under scanning electron microscope shows a clear rupture and degradation in hybrid epoxy coating after prolonged exposer to salt solution.

关键词： Hybrid Epoxy Electrochemical Impedance Spectroscopy Coatings