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Asian Pacific Journal of Tropical Biomedicine 2012年第10期2卷 793-797页

作者： Ananthan G karthikeyan mm Selva Prabhu A Raghunathan C Centre of Advanced Study in Marine Biology Faculty of Marine SciencesAnnamalai University Zoological Survey of India Andaman and NicobarRegional Station.1Horticulture RoadHaddoPort Blair744102

Objective:To investigate the seasonal fluctuations of the proximate composition of the ascidians ***:The moisture content was estimated by drying 1 g of fresh tissue at a constant temperature at 105(?)for 24 *** loss of weight was taken as moisture *** total protein was estimated using the Biuret *** total carbohydrate in dried sample was estimated spectrophotometrically following the phenol-sulphuric acid *** lipid in the dried sample tissue was gravimetrically estimated following the chloroform-methanol mixture *** content was determined gravimetrically by incinerating 1 g dried sample in muffle furnace at about 550℃for 6 h and results are expressed in ***:It was found very difficult to compare the monthly variations,as all the ten species,exhibited wide fluctuations in their proximate *** the sake of convenience,average seasonal values were calculated by summing the monthly ***:The proximate composition of the 10 commonly available ascidians showed high nutritive value and hence these groups especially solitary ascidians can be recommended for human consumption in terms of pickles,soup,curry and others after ensuring the safety of consumers.

关键词： Ascidians Biochemical composition Seasonal variations proximate composition

Polymer-Sandwich Ultra-Thin Silicon(100) Platform for Flexible Electronics

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Chinese Physics Letters 2016年第6期33卷 86-89页

作者：张永华 S.karthikeyan 张健 Department of Electronic Science and Engineering East China Normal University Department of Electrical and Computer Engineering University of Minnesota

As a potential flexible substrate for flexible electronics, a polymer-sandwiched ultra-thin silicon platform is stud- ied. SU-8 photoresist coated on the silicon membrane improves its flexibility as shown by an ANSYS simulation. Using the plasma enhanced chemical vapor deposited Si02/Si3N4 composite film as an etching mask, a 4＂ silicon- （100） wafer is thinned to 26[tm without rupture in a 30wt.% KOH solution. The thinned wafer is coated on both sides with 20 pm of SU-8 photoresist and is cut into strips. Then the strips are bent by a caliper to measure its bending radius. A sector model of bending deformation is adopted to estimate the radius of curvature. The determined minimal bending radius of the polymer-sandwiched ultra-thin silicon layer is no more than 3.3mm. The fabrication process of this sandwich structure can be used as a post-fabrication process for high performance flexible electronics.

关键词： of for Platform for Flexible Electronics PECVD is in

Influence of variables in deep drawing of AA 6061 sheet

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Transactions of Nonferrous Metals Society of China 2010年第10期20卷 1856-1862页

作者： S.RAJU G.GANESAN R.karthikeyan Department of Manufacturing Engineering Annamalai University Department of Mechanical Engineering

Deep drawing is one of the most important processes for forming sheet metal *** is widely used for mass production of cup shapes in automobile,aerospace and packaging *** drawing,besides its importance as forming process,also serves as a basic test for the sheet metal *** effect of equipment and tooling parameters results in complex deformation *** of thickness variation in the formed part may cause stress concentration and may lead to acceleration of *** TAGUCHI's signal-to-noise ratio,it is determined that the die shoulder radius has major influence followed by blank holder force and punch nose radius on the thickness distribution of the deep drawn cup of AA 6061 *** optimum levels of the above three factors,for the most even wall thickness distribution,are found to be punch nose radius of 3 mm,die shoulder radius of 8 mm and blank holder force of 4 kN.

关键词： deep drawing aluminium alloy thickness distribution signal to noise ratio

Effect of Low Feed Rate FSP on Microstructure and Mechanical Properties of Extruded Cast 2285 Aluminum Alloy

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Journal of Materials Science & Technology 2007年第5期23卷 614-618页

作者： L.karthikeyan V.S.Senthilkumar D.Viswanathan S.Natarajan Department of Mechanical Engineering Panimalar Engineering CollegeChennai-103TamilNaduIndia Department of Mechanical Engineering College of EngineeringAnna UniversityChennai-025TamilNaduIndia

Friction stir processing （FSP）, a variation of FSW （friction stir welding） is an emerging surface engineering technology that can locally eliminate casting defects and refine microstructures, thereby improving the mechanical properties of material. FSP can also produce fine grained microstructures through the thickness to impart superplasticity. The technology involves plunging a rapidly rotating, non consumable tool, comprising a profiled pin and larger diameter shoulder, into the surface and then traversing the tool across the surface. The pin and the shoulder friction heat the surface which alters the grain structure in the processed area thereby improving the mechanical properties. This paper presents the effects of FSP on microstructure and mechanical properties of extruded cast 2285 aluminum alloy at three different feed rates viz. 10, 12 and 15 mm/min. With the increase in the feed speed the material was observed to have increased impact strength. FSP also increased the tensile and yield strengths with increases in hardness and ductility values also. The observation has been listed in detail and pictorially represented.

关键词： Friction stir processing Feed rate Fine grain microstructure

Tribological and vibrational characteristics of AISI 316L tested at elevated temperature and 600 Torr vacuum

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Defence Technology（防务技术） 2019年第1期15卷 58-64页

作者： K.Arul Raj M.P.Arunkumar P.K.C.Kanigalpula M.karthikeyan Department of Mechanical Engineering Koneru Lakshmaiah Education Foundation Department of Mechanical Engineering RajaRajeswari College of Engineering

Friction and wear studies enable the investigation of material interaction between two sliding surfaces in contact. In the present investigation, the coefficient of friction and the wear resistance of AISI 316 L parts were studied under self-mating, dry sliding conditions using a pin-on-disc type configuration. The experiments were conducted at vacuum based high temperature pin-on-disc tribometer. The 4 mm diameter pin and 180 mm diameter disc were subjected to varying sliding velocities(0.5, 0.75 and 1.5 m/s) and were operated in 200, 400, 500 and 580 ℃ temperature at 600 Torr vacuum. The variation of specific wear rates with sliding velocities and different environmental conditions was studied. The morphology of sliding/rubbed surfaces was observed using Scanning Electron Microscope. In summary, it was found that a severe to mild wear transition occurred in sliding under operating conditions. Increased wear rates have been observed for 500 and 580 ℃ with increasing sliding velocity. Adhesive wear has been found to be predominant at 500 and 580 ℃ where as de-lamination has been observed at ambient temperature,200 and 400 ℃ in vacuum. The present paper also carried out the numerical analysis of the vibration behavior of AISI 316 L under thermal environment. Results revealed that at high temperature vibrational amplitude and natural frequency is significantly reduced. This can be attributed to the reduction in stiffness of the material at elevated temperatures. This high amplitude vibration during service can lead to high wear rate.

关键词： Pin-on-disc Sliding wear Vacuum De-lamination Scanning electron microscope Vibration

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Journal of Biophysical Chemistry 2010年第1期1卷 72-75页

作者： B. karthikeyan V. Srinivasan Department of Chemistry Annamalai university Annamalainagar India

ABSTRACT A simple, economic, and time-efficient related substance, GC method has been developed for the analysis of 1,4-Cyclohexanedione mono- ethylene ketal(will be specified as ketal) in the presence of a potential impurity 1,4-cyclohexa- nedione bis (ethylene ketal) [will be specified as diketal]. Successful chromatographic separa- tion of the ketal from the impurity was achieved on a DBWAX ETR, 30 m x 0.32 mm x 1.0μ FT column with nitrogen as carrier gas and FID detector. The method was validated for linearity, accuracy, precision, and specificity and can be used for quality control during manufacture of ketal. A validated GC method is reported for the ketal for the first time.

关键词： Column Gas Chromatography 1 4-Cyclohexanedione Mono-Ethylene Ketal 4-Cyclohexanedione Bis (Ethylene Ketal) Validation

Performance Enhancement of the Proton Exchange Membrane Fuel Cell Using Pin Type Flow Channel with Porous Inserts

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Journal of Power and Energy Engineering 2015年第5期3卷 1-10页

作者： Vaibhav Pal P. karthikeyan R. Anand Department of Mechanical Engineering National Institute of Technology Tiruchirappalli India Department of Automobile Engineering PSG College of Technology Coimbatore India

The design of the flow field is highly responsible for the performance of the Proton Exchange Membrane Fuel Cell (PEMFC). In this study, pin type flow channel is numerically analyzed by arranging carbon made porous material in uniform and zigzag manner on the rib surface of the flow field. The study focuses on enhancing the performance of PEMFC by reducing liquid flooding in the interface between the rib and Gas Diffusion Layer (GDL). A single PEMFC having an active area of 25 cm2, with three flow channel designs (conventional serpentine, pin type flow channel with 2 mm cubical porous inserts in zigzag and uniform pattern) are modeled for the numerical analysis. The effect of porosity of the carbon inserts on the cell performance is studied by varying its value from 0.6 to 0.9. The results show that the performance of the flow channel with zigzag and uniformly positioned porous inserts is more than the conventional serpentine flow channel by 20.36% and 16.87% respectively. The reason for this increase is the removal of the accumulated water from the rib surface due to the capillary action of the porous carbon inserts. This helps in eliminating the stagnant water regions under the rib and thereby helps in reducing liquid flooding.

关键词： Flooding Uniform and Zigzag Pin Type Porosity Porous Carbon Inserts