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Journal of Rare Earths 2013年第5期31卷 477-484页

作者： Azhagapillai Prabhu Ahmed Al Shoaibi Chandrasekar Srinivasakannan Muthaiahpillai Palanichamy velayutham murugesan Department of Chemical Engineering The Petroleum InstituteAbu DhabiUAE Department of Chemistry Anna University

Cerium incorporated KIT-6 mesoporous materials were synthesized through direct hydrothermal method and characterized by using X-ray diffraction （XRD）, nitrogen sorption isotherm （BET）, Fourier transform infrared spectroscopy （FT-IR）, inductively coupled plasma - atomic emission spectroscopy （ICP-AES）, diffuse reflectance ultraviolet visible spectroscopy （DRS-UV-Vis）, ther- mogravimetric analysis （TGA）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM） methods. It ap- peared that stable cerium ions were inserted into the silica framework of KIT-6, thus generating acid properties in their host materials. The catalytic activity of Ce-KIT-6 materials was evaluated in the vapor phase dehydration of cyclohexanol to cyclohexene and dicy- clohexyl ether at different temperatures with various Si/Ce molar ratios. Ce-KIT-6 （25） showed higher activity with 54% cyclohexa- nol conversion and 64% selectivity to cyclohexene. The catalytic results indicated that Ce-KIT-6 mesoporous materials could be used as versatile and stable acid catalysts.

关键词： Ce-KIT-6 dehydration eyclohexanol cyclohexene dicyclohexyl ether rare earths

CeAlPO-5分子筛催化剂上二苯基甲烷选择性氧化生成二苯甲酮(英文)

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催化学报 2012年第7期33卷 1086-1094页

作者： Subbiah DEVIKA Muthiahpillai PALANICHAMY velayutham murugesan Department of Chemistry Anna University

Selective oxidation of diphenylmethane to benzophenone requires active and selective catalysts. The framework incorporation of cerium in AlPO-5 molecular sieves creates active cerium sites in isolation. These active sites are responsible for selective oxidation. Cerium incorporated AlPO-5 with different Al/Ce ratios were synthesized, and the vapor phase oxidation of diphenylmethane in air over these catalysts was studied at 250, 275, 300, 325, and 350 °C. The diphenylmethane conversion and selectivity for benzophenone were more than 90%. CeAlPO-5(25) was found to be more active than other catalysts. The stability of the catalyst was verified by the time on stream study which indicated steady diphenylmethane conversion and benzophenone selectivity. Hence framework incorporated CeAlPO-5 molecular sieves are stable and active catalysts for the selective oxidation of diphenylmethane.

关键词： CeAlPO-5 molecular sieve hydrothermal synthesis oxidation diphenylmethane benzophenone

Al-MCM-48分子筛对苯酚与乙酸异丙酯异丙基化反应的催化性能(英文)

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催化学报 2012年第3期33卷 478-486页

作者： Kandan VENKATACHALAM Pitchai VISUVAMITHIRAN Balachandran SUNDARAVEL Muthiapillai PALANICHAMY velayutham murugesan Department of Chemistry Anna University

Al-MCM-48 molecular sieves (Si/Al molar ratios = 25, 50, 75, and 100) were synthesized hydrothermally using cetyltrimethyl-ammonium bromide as the structure directing template. The orderly arrangement of mesopores was evident from the low angle X-ray diffraction patterns and transmission electron microscopy images. The catalytic performance of the materials was evaluated in the vapor phase isopropylation of phenol with isopropyl acetate. Phenol conversion decreased with the increase in the Si/Al ratio of the catalysts. The major reaction product was 4-isopropyl phenol with 78% selectivity. The delocalization of phenolic oxygen electron pair over the aromatic ring promoted para-selective alkylation. Such delocalization could be aided by the hydrophilic surface of the molecular sieves. Although an ester was used as the alkylating agent, phenyl isopropyl ether was not formed in the reaction.

关键词： MCM-48分子筛异丙基苯酚醋酸异丙酯催化性能十六烷基三甲基溴化铵透射电子显微镜反应产物水热法合成

ZSM-5沸石结晶度对乙苯叔丁基化对位选择性的影响(英文)

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催化学报 2013年第2期34卷 294-304页

作者： PUSHPARAJ Hemalatha MANI Ganesh MUTHIAHPILLAI Palanichamy velayutham murugesan PARK Yong-Ki CHOI Won Choon JANG Hyun Tae Department of Chemical Engineering Hanseo University Seosan-si 356 706 South Korea Department of Chemistry Anna University Chennai 600 025 India Green Chemistry Research Division Korea Research Institute of Chemical Technology Jang-dong 100. Daejeon 305 600 South Korea

Highly crystalline ZSM-5 zeolites are important for para-selective alkylation of alkyl aromatics, because they carry few external acid sites for isomerization of p-dialkyl products. Such zeolites (Si/Al = 25, 50, and 75) were synthesized in a fluoride medium between pH 4 and 6. Their crystallinities, crystal sizes, and surface areas were higher than those of a commercial ZSM-5 zeolite. Their para selectivities in alkylation were tested for vapor-phase tert-butylation of ethylbenzene between 200 and 400 °C. As expected, all the catalysts showed more than 90% para selectivity. At 300 °C, ethylbenzene conversion decreased in the order ZSM-5(25, commercial) > ZSM-5(25) > ZSM-5(50) > ZSM-5(75). The catalysts had weak, medium, and strong acid sites, but all the acid sites of ZSM-5(75) were weaker than those of ZSM-5(25) and ZSM-5(50). The high activity of commercial ZSM-5 was caused by its strong acid sites being stronger than those of the synthesized zeolites. Although the activity of the commercial catalyst was higher than those of the present catalysts, the selectivity for 4-t-butylethylbenzene (4-t-BEB) was low. The optimum feed ratio (ethylbenzene:t-butyl alcohol) was 2:1 and the feed rate was 1.65 h?1 for high ethylbenzene conversion and 4-t-BEB selectivity. Time-on-stream studies showed slow catalyst deactivation. Highly crystalline ZSM-5 zeolites are therefore better than a commercial zeolite for para-selective alkylation of alkyl aromatics. They do not require much post-modification for high para selectivity. A fluoride medium is therefore better than an alkaline medium for obtaining highly crystalline para-selective ZSM-5 zeolites.

关键词： ZSM-5 Fluoride medium P-selectivity Ethylbenzene Tert-butylation Zeolite

Behaviour of micro-and nano-alumina-reinforced Mg-3Zn-0.7Zr-1Cu alloy composites processed at different sintering temperatures

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Rare Metals 2021年第1期40卷 143-155页

作者： Eacherath Suneesh murugesan Sivapragash Department of Production Engineering Vidya Academy of Science and TechnologyThrissur 680501.India Department of Mechanical Engineering PSN College of Engineering and TechnologyTirunelveli 627152Ind

This study aims to develop a magnesium-based hybrid composite via a powder metallurgy(PM)technique by simultaneously reinforcing the matrix(Mg-3 Zn-0.7 Zr-1 Cu)alloy with micro-alumina(3.0 wt%)and nano-alumina(0.5 wt%and 1.0 wt%)*** extensive processing involved two different sintering temperatures(400 and 450℃)followed by hot extrusion and a heat treatment *** study aimed to add to our understanding of the effects of sintering temperature and alumina content on the physical characteristics of Mg-based *** was revealed that increasing sintering temperature improves the density of composites by increasing their diffusion *** addition,significant improvements in the hardness,tensile properties and compressive properties of the composites were observed at higher sintering *** was also discovered that composites with higher alumina concentrations experienced agglomeration and were more porous than other composites.A micro-structural examination showed that composites with higher concentrations of nano-alumina had a finer grain structure than other composites and underwent a marginal reduction in grain ***,the tensile and compressive properties of composites decreased when the nano-alumina content was increased to 1.0 wt%.The magnesium hybrid composite containing 3.0 wt%micro-alumina and 0.5 wt%nano-alumina sintered at 450℃displayed the greatest tensile strength properties in all composites studied.A transformation from brittle to mixed-mode failure,with sufficient evidence of increased plastic deformation,was also noted in the hybrid *** present study suggests that adding up to 0.5 wt%nano-alumina and employing a higher sintering temperature enhances the overall characteristics of magnesium/alumina microcomposites.

关键词： Hybrid composite Powder metallurgy Alumina particulates Sintering temperature Mechanical characteristics

Ionic liquid mediated morphologically improved lanthanum oxide nanoparticles by Andrographis paniculata leaves extract and its biomedical applications

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Journal of Rare Earths 2020年第3期38卷 281-291页

作者： Muthulakshmi Veerasingam Balaji murugesan Sundrarajan Mahalingam Advanced Green Chemistry Lab Department of Industrial ChemistrySchool of Chemical SciencesAlagappa UniversityKaraikudi03Tamil NaduIndia

Greener synthesis of ionic liquid(IL) assisted lanthanum oxide(La2O3) nanoparticles(NPs) was followed using Andrographis paniculata leaves extract by hydrothermal method at low temperature,The IL assisted La2O3(La2O3-IL) NPs were characterized by various properties such as structural,spectral,optical,morphological,and biological *** X-ray diffraction studies confirm that La2O3-IL NPs crystallize in the form of body-centered cubic structure and average crystalline size is shown-43 *** and Laser Raman spectroscopy confirm the La-O,O-H and various functional *** La-O stretching vibration band attributes at 639 *** optical property of La2O3-IL NPs was characterized by UV-Vis and photo luminesce nce *** sharp and intense absorbance peak observed in the UV region at 288 nm can be *** the PL spectrum,we observe two different emission bands like blue and green *** morphological and particle size determination were investigated by SEM with EDX spectra and TEM *** agglomerated particles of hexagonal,spherical,and parallelogram shape are observed in the TEM *** chemical elements,binding energies as well as La metal states on the surface of these synthesized NPs were determined using ***2O3 NPs for good biological activities regarding antibacterial and anti-inflammatory potentials could be utilized in different biological applications to the food and biomedical ***2O3-IL has a high percentage of inhibitions than La2O3 and standard diclofenac.

关键词： La2O3 nanoparticles Ionic liquid X-ray diffraction X-ray photoelectron spectroscopy Antibacterial Anti-inflammatory

Impact of nanoparticle shape on thermo-solutal buoyancy induced lid-driven-cavity with inclined magnetic-field

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Propulsion and Power Research 2022年第1期11卷 97-117页

作者： Ratnadeep Nath Krishnan murugesan Department of Mechanical and Industrial Engineering Indian Institute of Technology RoorkeeRoorkee247667India

The aim of this paper is to numerically investigate the influence of nanoparticles shape on heat and mass transport phenomena in a moving lid cavity under the combined effect of thermo-solutal buoyancy force and magnetic *** governing equations are transformed into velocity-vorticity form of equations and solved using Galerkin's weighted residual *** analysis has been carried out with parameters like buoyancy ratio(−5≤N≤5),magnetic field inclination angle(0°≤ϕ≤90°)with four shapes of Al_(2)O_(3) nanoparticle like bricks,blades,platelets and *** results revealed that the shape factor on Nusselt number is significant depending upon the inclined magnetic field and buoyancy ratio whereas on mass transfer the shape effect is *** diffusion mode of transport process is stronger than the convection mode at higher inclination angle of magnetic *** on a given value of N andϕ,blade and cylinder shows the best performance in Nusselt and Sherwood number respectively except the platelet shape that shows maximum frictional loss in terms of wall shear stress.

关键词： Velocity-vorticity formulation Thermo-solutal buoyancy forces Nanofluid Shapes of nanoparticles Inclined magnetic field

Protective effect of tannins from Ficus racemosa in hypercholesterolemia and diabetes induced vascular tissue damage in rats

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Asian Pacific Journal of Tropical Medicine 2012年第5期5卷 367-373页

作者： velayutham Ravichandiran Sankaradoss Nirmala KFH Nazeer Ahamed Department of Pharmacognosy School of Pharmaceutical SciencesVels Institute of Science Technology and Advanced Studies(VISTAS)Vels UniversityPallavaramChennai 600 117India Department of Pharmacology School of Pharmaceutical Sciences.Vels Institute of Science Technology and Advanced Studies(VISTAS)Vels UniversityPallavaramChennai 600 117India

Objective:To evaluate the protective effect of tannins from Ficus racemosa(***) on the lipid profile and antioxidant parameters in high fat meal and streptozotocin induced hypercholestremia associated diabetes model in ***:The crude tannin fraction was separated from the acetone(70%v/v) bark extract of *** administratipn of tannin fraction(TF)(100 & 200 mg/kg body weight) to rats fed with high fat meal for 30 days (4%cholesterol,1%cholic acid,0.5%egg albumin) and injected with streptozotocin(35 mg/ kg *** citrate buffer on 14th day).Results:The administration of TF significantly reverse the increased blood glucose,total cholesterol,triglycerides,low density lipoprotein and also significandy restored the insulin and high density lipoprotein in the *** addition tannins significantly restored the activity of antioxidant enzymes such as superoxide dismutase,catalase and decreased the,glutathione peroxidase,and glutathione,thereby restoring the antioxidant status of the organs to almost normal ***:The results of this study show that two different doses of tannin supplementation had a favorable effect on plasma glucose and lipid profile *** also had an influence on attenuating oxidative stress in diabetic tats.

关键词： Diabetes Vascular tissue damage Streptozotocin Tannins Rat

Effect of alkyl chain length on the thermophysical properties of pyridinium carboxylates

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Chinese Journal of Chemical Engineering 2017年第9期25卷 1266-1272页

作者： Tazien Rashid Chong Fai Kait Thanabalan murugesan Department of Chemical Engineering Universiti Teknologi PETRONAS Bandar Seri Iskandar Fundamental and Applied Sciences Department Universiti Teknologi PETRONAS Bandar Seri Iskandar

In the present study, new series of pyridinium carboxylate protic ionic liquids(PILs) were synthesized by pairing pyridinium cation with carboxylate anion from C_1–C_3 forming pyridinium formate([C_5H_6N^+][HCOO^-]),pyridinium acetate([C_5H_6N^+][CH_3COO^-]) and pyridinium propionate([C_5H_6N^+][CH_3CH_2COO^-]) *** physical properties namely, density, viscosity, surface tension(298.15–343.15) K, and refractive index(293.15–323.15) K were measured. Thermal properties namely, glass transition temperature, molar heat capacity, and thermal decomposition temperatures were also determined. The thermal expansivity was calculated using the experimental density data. The effect of increasing the alkyl chain length on the thermophysical properties of the pyridinium carboxylate PILs has been evaluated. As expected the physical properties i.e. density,viscosity, surface tension and refractive index of the investigated pyridinium carboxylates decreased with increasing temperature. In general pyridinium carboxylate PILs possessed low viscosity, high thermal stability and excellent hydrogen bonding capability, and these properties lead them to outperform conventional solvents employed for lignin dissolution.

关键词： Protic ionic liquids Pyridine Carboxylic acids Anion Physicochemical properties

Application of remote sensing and GIS analysis for identifying groundwater potential zone in parts of Kodaikanal Taluk, South India

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Frontiers of Earth Science 2013年第1期7卷 65-75页

作者： murugesan BAGYARAJ Thirunavukkarasu RAMKUMAR Senapathi VENKATRAMANAN Balasubramanian GURUGNANAM Department of Earth Sciences Annamalai University Annamalai Nagar 608002 India Department of Geology Gandhigram Rural Institute Deemed University Gandhigarm 624302 India

Groundwater potential zones were demarcated with the help of remote sensing and Geographic Informa- tion System （GIS） techniques. The study area is composed rocks of Archaean age and chamockite dominated over others. The parameters considered for identifying the groundwater potential zone of geology slope, drainage density, geomorphic units and lineament density were generated using the resource sat （IRS P6 LISS IV MX） data and survey of India （SO1） toposheets of scale 1：50000 and integrated them with an inverse distance weighted （IDW） model based on GIS data to identify the ground- water potential of the study area. Suitable weightage factors were assigned for each category of these para- meters. For the various geomorphic units, weightage factors were assigned based on their capability to store ground-water. This procedure was repeated for all the other layers and resultant layers were reclassified. The reclassi- fied layers were then combined to demarcate zones as very good, good, moderate, low, and poor. This groundwater potentiality information could be used for effective identification of suitable locations for extraction of potable water for rural populations.

关键词： remote sensing GIS slope geomorphic lineament Kodaikanal