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International Journal of Organic Chemistry 2015年第4期5卷 271-281页

作者： Thangavelu Saravanan Anju Chadha Tarur Konikkaledom Dinesh Namasivayam Palani sengottuvelan balasubramanian Laboratory of Bioorganic Chemistry Department of Biotechnology Indian Institute of Technology Madras Chennai India National Center for Catalysis Research Indian Institute of Technology Madras Chennai India Department of Inorganic Chemistry University of Madras Guindy Campus Chennai India ITC Life Sciences and Technology Centre ITC Limited Peenya Industrial Area Phase I Bangalore India

Enantiomerically enriched (R)-1-(2-bromocycloalkenyl)-3-buten-1-ol and its derivatives were obtained via enantioselective hydrolysis [resolution] with good enantioselectivities (E = 31 to >500) using Candida parapsilosis ATCC 7330. The various reaction parameters were optimized for enantioselective hydrolysis to achieve high enantiomeric excess (ee) and conversions. Among the substrates tested, (RS)-1-(2-bromocyclohex-1-en-1-yl) but-3-yn-1-yl acetate was hydrolysed by the biocatalyst in 12 h to the corresponding (R)-alcohol in 49% conversion and >99 ee. The optically pure allylic alcohol thus obtained was used as a chiral starting material for the synthesis of an enantiomerically enriched bicyclic alcohol effectively establishing achemoenzymatic route.

关键词： Chemoenzymatic Synthesis Enantioselective Hydrolysis Candida parapsilosis ATCC 7330 Hydrolases Bicyclic Carbocycle

Bioactivation of titanium dioxide scaffolds by ALP-functionalization

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Bioactive Materials 2017年第2期2卷 108-115页

作者： A.sengottuvelan P.balasubramanian J.Will A.R.Boccaccini Department of Materials Science and Engineering Institute of BiomaterialsUniversity of Erlangen-NurembergCauerstraße 691058 ErlangenGermany

Three dimensional TiO2 scaffolds are receiving renewed attention for bone tissue engineering (TE) due totheir biocompatibility and attractive mechanical properties. However the bioactivity of these scaffolds iscomparatively lower than that of bioactive glass or hydroxyapatite (HA) scaffolds. One strategy toimprove bioactivity is to functionalize the surface of the scaffolds using biomolecules. Alkaline phosphatase(ALP) was chosen in this study due to its important role in the bone mineralization process. Thecurrent study investigated the ALP functionalization of 3D titanium dioxide scaffolds using selfpolymerizationof dopamine. Robust titanium scaffolds (compressive strength^2.7 ± 0.3 MPa) wereproduced via foam replica method. Enzyme grafting was performed by dip-coating in polydopamine/ALPsolution. The presence of ALP was indirectly confirmed by contact angle measurements and enzymaticactivity study. The influence of the enzyme on the bioactivity, e.g. hydroxyapatite formation on thescaffold surface, was measured in simulated body fluid (SBF). After 28 days in SBF, 5 mg ALP coatedtitania scaffolds exhibited increased hydroxyapatite formation. It was thus confirmed that ALP enhancesthe bioactivity of titania scaffolds, converting an inert bioceramic in an attractive bioactive system forbone TE.

关键词： Alkaline phosphatase Titanium dioxide Scaffolds Polydopamine Surface modification Bioactivity

Effect of process parameters on SPRC35 spot welded automotive panels

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Acta Metallurgica Sinica(English Letters) 2010年第3期23卷 185-190页

作者： M.balasubramanian V.balasubramanian Department of Mechanical Engineering Velammal Engineering College Department of Manufacturing Engineering Annamalai University

This paper presents an experimental study on the resistance spot weldability of SPRC35（steel plate re-phosphorised cold rolled） *** sheets were joined by using resistance spot welding as lap *** weld nugget diameter and tensile shear force were ***-shear tests were applied to the welded specimens to understand the tensile shear force that the joint can *** relationships were developed for both nugget diameter and tensile shear *** of automatic mode, will increase the dependence on the use of equations to predict the nugget *** developed models have been checked for their adequacy and significance by the F test and t test *** results obtained from the empirical relationships have been optimized and also tested using conformity test runs.

关键词： Resistance spot welding SPRC35 steel

Effect of process parameters of pulsed current tungsten inert gas welding on weld pool geometry of titanium welds

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Acta Metallurgica Sinica(English Letters) 2010年第4期23卷 312-320页

作者： M.balasubramanian V.Jayabalan V.balasubramanian Department of Mechanical Engineering Velammal Engineering CollegeSurapetAnna University Department of Manufacturing Engineering Anna University Centre for Materials Joining & Research Department of Manufacturing EngineeringAnnamalai University

The effects of pulsing current parameters on weld pool geometry namely front height, back height, front width and back width of pulse current gas tungsten arc welded （GTAW） titanium alloy was analysed. Four factors, five levels, central composite design were used to develop empirical relationships, incorporating pulsed current parameters and weld pool geometry.

关键词： Gas tungsten arc welding Pulsed current Titanium alloy Design of experiments

Optimizing the Pulsed Current Gas Tungsten Arc Welding Parameters

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Journal of Materials Science & Technology 2006年第6期22卷 821-825页

作者： M.balasubramanian V.Jayabalan V. balasubramanian Department of Production Engineering Sathyabama Institute of Science and TechnologyIndia Department of Manufacturing Engineering Anna UniversityIndia Department of Manufacturing Engineering Annamalai UniversityIndia

The selection of process parameter in the gas tungsten arc （GTA） welding of titanium alloy was presented for obtaining optimum grain size and hardness. Titanium alloy （Ti-6Al-4V） is one of the most important non-ferrous metals which offers great potential application in aerospace, biomedical and chemical industries, because of its low density （4.5 g/cm^3）, excellent corrosion resistance, high strength, attractive fracture behaviour and high melting point （1678℃）. The preferred welding process for titanium alloy is frequent GTA welding due to its comparatively easier applicability and better economy. In the case of single pass （GTA） welding of thinner section of this alloy, the pulsed current has been found beneficial due to its advantages over the conventional continuous current process. Many considerations come into the picture and one needs to carefully balance various pulse current parameters to reach an optimum combination. Four factors, five level, central composite, rotatable design matrix were used to optimize the required number of experimental conditions. Mathematical models were developed to predict the fusion zone grain size using analysis of variance （ANOVA） and regression analysis. The developed models were optimized using the traditional Hooke and Jeeve＇s algorithm. Experimental results were provided to illustrate the proposed approach.

关键词： Pulsed current Gas tungsten arc welding Titanium alloy Design of experiments ANOVA, Hooke and Jeeve's algorithm Grain size Hardness

Processing and design methodologies for advanced and novel thermal barrier coatings for engineering applications

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Particuology 2016年第4期14卷 1-28页

作者： Vijay Kumar balasubramanian Kandasubramanian Department of Materials Engineering Defence Institute of Advanced Technology Girinagar Pune 411025 India

Thermal barrier coating is a crucial thermal insulation technology that enables the underlying substrate to operate near or above its melting temperature. Such coatings bolster engineers＇ perpetual desire to increase the power and efficiency of gas turbine engines through increasing the turbine inlet tempera- ture. Advances in recent years have made them suitable for wider engineering and defense applications, and hence they are currently attracting considerable attention. A thermal barrier coating system is itself dynamic; its components undergo recurrent changes in their composition, microstructure and crystalline phases during its service life. Nevertheless, the performance of multi-layered and multi-material sys- tems tailored for high temperature applications is closely linked to the deposition process. The process improvements achieved so far are the outcome of increased understanding of the relationship between the coating morphology and the operating service conditions, as well as developments in characterization techniques. This article presents a comprehensive review of various processing techniques and design methodologies for thermal barrier coatings. The emphasis of this review is on the particle technology; the interrelationship between particle preparation, modification and the resulting properties, to assist developments in advanced and novel thermal barrier coatings for engineering applications.

关键词： Thermal barrier coatingAir plasma sprayElectron beam-physical vapor depositionThermally grown oxideYttria-stabilized zirconiaThermal conductivity

Process Parameter Optimization of the Pulsed Current Argon Tungsten Arc Welding of Titanium Alloy

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Journal of Materials Science & Technology 2008年第3期24卷 423-426页

作者： M.balasubramanian V.Jayabalan V.balasubramanian Department of Mechanical Engineering Maamallan Institute of Technology Department of Manufacturing-Engineering Anna University Department of Manufacturing Engineering Annamalai University

The selection of process parameters for obtaining optimal tensile properties in the pulsed current gas tungsten arc welding is presented. The tensile properties include ultimate tensile strength, yield strength and notch tensile strength. All these characteristics are considered together in the selection of process parameters by modified taguchi method to analyse the effect of each welding process parameter on tensile properties. Experimental results are furnished to illustrate the approach.

关键词： Pulsing current Modified taguchi method Tensile properties

Modeling corrosion behavior of gas tungsten arc welded titanium alloy

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中国有色金属学会会刊：英文版 2007年第4期17卷 676-680页

作者： M. balasubramanian V. Jay abalan V. balasubramanian Department of Mechanical Engineering Maamallan Institute of Technology Anna University Department of Manufacturing Engineering Anna University Department of Manufacturing Engineering Annamalai University

The pitting corrosion characteristics of pulse TIG welded Ti-6Al-4V titanium alloy in marine environment were explained. Besides the rapid advance of titanium metallurgy, this is also due to the successful solution of problems associated with the development of titanium alloy welding. The preferred welding process of titanium alloy is frequently gas tungsten arc(GTA) welding due to its comparatively easier applicability and better economy. In the case of single pass GTA welding of thinner section of this alloy, the pulsed current has been found beneficial due to its advantages over the conventional continuous current process. The benefit of the process is utilized to obtain better quality titanium weldments. Four factors, five levels, central composite, rotatable design matrix are used to optimize the required number of experiments. The mathematical models have been developed by response surface method(RSM). The results reveal that the titanium alloy can form a protective scale in marine environment and is resistant to pitting corrosion. Experimental results are provided to illustrate the proposed approach.

关键词：钛合金脉冲电流钨电极惰性气体保护焊腐蚀行为

Evaluation of Microstructure and Mechanical Properties of Laser Beam Welded AISI 409M Grade Ferritic Stainless Steel

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Journal of Iron and Steel Research International 2012年第1期19卷 72-78页

作者： A K Lakshminarayanan V balasubramanian Department of Manufacturing Engineering Annamalai University

The microstructure analysis and mechanical properties evaluation of laser beam welded AISI 409M ferritic stainless steel joints are investigated. Single pass autogeneous welds free of volumetric defects were produced at a welding speed of 3 000 mm/min. The joints were subjected to optical microscope, scanning electron fractographe, microhardness, transverse and longitudinal tensile, bend and charpy impact toughness testing. The coarse ferrite grains in the base metal were changed into dendritic grains as a result of rapid solidification of laser beam welds. Tensile testing indicates overmatching of the weld metal is relative to the base metal. The joints also exhibited acceptable impact toughness and bend strength properties.

关键词： laser beam welding ferritic stainless steel tensile property impact property

Effect of Welding Processes and Consumables on Tensile and Impact Properties of High Strength Quenched and Tempered Steel Joints

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Journal of Iron and Steel Research International 2008年第6期15卷 87-94页

作者： G Magudeeswaran V balasubramanian G Madhusudhan Reddy T S balasubramanian Center for Advanced Materials Joining and Research(CEMAJOR) Department of Manufacturing EngineeringAnnamalai University Metal Joining Section Defence MetallurgicalResearch Laboratory Special Vehicles Division Combat Vehicles Research and Development Establishment

Quenched and tempered steels are prone to hydrogen induced cracking in the heat affected zone after welding. The use of austenitic stainless steel consumables to weld the above steel was the only available remedy because of higher solubility for hydrogen in austenitic phase. In this investigation, an attempt was made to determine a suitable consumable to replace expensive austenitic consumables. Two different consumables, namely, austenitie stain less steel and low hydrogen ferritic steel, were used to fabricate the joints by shielded metal are welding （SMAW） and flux cored arc welding （FCAW） processes. The joints fabricated by using low hydrogen ferritic steel consumables showed superior transverse tensile properties, whereas joints fabricated by using austenitic stainless steel consumables exhibited better impact toughness, irrespective of the welding process used. The SMAW joints exhibited superior mechanical and impact properties, irrespective of the consumables used, than their FCAW counterparts.

关键词： shielded metal arc welding process flux cored arc welding process austenitie stainless steel low hydro gen ferritic steel transverse tensile property impact toughness