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Transactions of Nonferrous Metals Society of China 2014年第9期24卷 2805-2814页

作者： P.SURESH k.marimuthu S.RANGANATHAN T.RAJMOHAN School of Mechanical Engineering Galgotias University Greater Noida 201306 Uttar Pradesh India Coimbatore Institute of Technology Coimbatore 641014 Tamilnadu India Saveetha School of Engineering Saveetha University Chennai- 602105 Tamilnadu India Sri Chandrasekharendra Saraswathi Viswa Maha Vidyalaya University kanchipuram 631561 India

Metal matrix composites reinforced with graphite particles provide better machinability and tribological properties. The present study attempts to find the optimal level of machining parameters for multi-performance characteristics in turning of Al-SiC-Gr hybrid composites using grey-fuzzy algorithm. The hybrid composites with 5%, 7.5% and 10% combined equal mass fraction of SiC-Gr particles were used for the study and their corresponding tensile strength values are 170, 210, 204 MPa respectively. Al-10%（SiC-Gr） hybrid composite provides better machinability when compared with composites with 5% and 7.5% of SiC-Gr. Grey-fuzzy logic approach offers improved grey-fuzzy reasoning grade and has less uncertainties in the output when compared with grey relational technique. The confirmatory test reveals an increase in grey-fuzzy reasoning grade from 0.619 to 0.891, which substantiates the improvement in multi-performance characteristics at the optimal level of process parameters setting.

关键词： hybrid composite turning optimization grey-fuzzy algorithm

Machining studies of die cast aluminum alloy-silicon carbide composites

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International Journal of Minerals,Metallurgy and Materials 2010年第5期17卷 648-653页

作者： Thambu Sornakumar marimuthu kathiresan Department of Mechanical Engineering Thiagarajar College of Engineering

Metal matrix composites （MMCs） with high specific stiffness, high strength, improved wear resistance, and thermal properties are being increasingly used in advanced structural, aerospace, automotive, electronics, and wear applications. Aluminum alloy-silicon carbide composites were developed using a new combination of the vortex method and the pressure die-casting technique in the present work. Machining studies were conducted on the aluminum alloy-silicon carbide （SiC） composite work pieces using high speed steel （HSS） end-mill tools in a milling machine at different speeds and feeds. The quantitative studies on the machined work piece show that the surface finish is better for higher speeds and lower feeds. The surface roughness of the plain aluminum alloy is better than that of the aluminum alloy-silicon carbide composites. The studies on tool wear show that flank wear increases with speed and feed. The end-mill tool wear is higher on machining the aluminum alloy-silicon carbide composites than on machining the plain aluminum alloy.

关键词： metal matrix composites aluminum alloys silicon carbide die casting milling surface roughness

Larvicidal and repellent properties of some essential oils against Culex tritaeniorhynchus Giles and Anopheles subpictus Grassi(Diptera:Culicidae)

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Asian Pacific Journal of Tropical Medicine 2011年第2期4卷 106-111页

作者： marimuthu Govindarajan Division of Vector Biology and Phytochemistry Department of ZoologyAnnamalai UniversityAnnamalainagar-608 002Tamil NaduIndia

Objective:To investigate the larvicidal and repellent properties of essential oils from various parts of four plant species Cymbopogan citrates,Cinnamomum zeylanicum,Rosmarinus of ficinalis and Zingiber of ficinale against Culex tritaeniorhynchus（***） and Anopheles subpictus（***）.Methods:Essential oils were obtained by hydro-distillation *** mosquitoes were reared in the vector control laboratory and twenty five late third ins tar larvae of *** and *** were exposed to based on the wide range and narrow range test,essential oil tested at various concentrations ranging from 25 to 250 *** larval mortality was observed after 24 h under the laboratory *** repellent efficacy was determined against two mosquito species at three concentrations viz., 1.0,2.5 and 5.0 mg/cm2 under laboratory ***:Results showed all the four plant essential oil produced significant larval mortality against two mosquito ***,the highest larvicidal activity was observed in the essential oil from Zingiber of ficinale against Cx. tritaeniorhynchus and *** with the LC50 and LC90 values as 98.83,57.98 ppm and 186.55, 104.23 ppm,*** the four essential oil shows significant repellency against Cx. tritaeniorhynchus than *** four essential oil tested the highest repellency was observed in Zingiber of ficinale,a higher concentration of 5.0 mg/cm2 provided 100%protection up to 150 and 180 min against *** and ***,***: In this work,it can be concluded that four essential oils which were distilled from Cymbopogan citrates,Cinnamomum zeylanicum,Rosmarinus of ficinalis and Zingiber of ficinale showed promising larvicidal and repellent agent against *** and ***.

关键词： Cymbopogan citrates Cinnamomum zeylanicum Rosmarinus officinalis Zingiber officinale Essential ois Larvicidal activity Repellent activity Mosquito vectors

Evaluation of Andrographis paniculata Burm.f.(***) extracts against Culex quinquefasciatus(Say.) and Aedes aegypti(Linn.)(Diptera:Culicidae)

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Asian Pacific Journal of Tropical Medicine 2011年第3期4卷 176-181页

作者： marimuthu Govindarajan Division of Vector Biology and Phytochemistry Department of ZoologyAnnamalai UniversityAnnamalainagar-608 002Tamil NaduIndia

Objective:To investigate the larvicidal and ovicidal efficacy of different extracts of Andrographis paniculata（***） against Culex quinquefasciatus（***） Say and Aedes aegypti（*** ） L（Diptera:Culicidae）.Methods:Larvicidal efficacy of the crude leaf extracts of *** with five different solvents like benzene,hexane,ethyl acetate, methanol and chloroform was tested against the early third instar larvae of *** and *** ovicidal activity was determined against two mosquito species to various concentrations ranging from 50-300 ppm under the laboratory ***:The benzene, hexane,ethyl acetate,methanol and chloroform leaf extract of *** was found to be more effective against *** than *** LC50 values were 112.19,137.48, 118.67,102.05,91.20 ppm and 119.58,146.34,124.24,110.12,99.54 ppm *** five tested solvent,methanol and ethyl acetate crude extract was found to be most effective for ovicidal activity against two mosquito *** extract of methanol and ethyl acetate exerted 100%mortality at 200 ppm against *** and at 250 ppm against ***. Conclusions:From the results it can be concluded the crude extract of *** was a potential for controlling *** and *** mosquitoes.

关键词： Andrographis paniculata larvicidal activity Ovicidal activity Culex quinquefasciatus Aedes aegypti

Chemical composition and larvicidal activity of leaf essential oil from Clausena anisata (Willd.) *** Benth (Rutaceae) against three mosquito species

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Asian Pacific Journal of Tropical Medicine 2010年第11期3卷 874-877页

作者： marimuthu Govindarajan Division of Phytochemistry and Vector Biology Department of ZoologyAnnamalai UniversityAnnamalai Nagar-608 002India

Objective:To determine the mosquito larvicidal activity of leaf essential oil and their chemical constituents from Clausena anisata（***）（Willd.） *** *** Culex quinquefasciatus,Aedes aegypti and Anopheles ***:Essential oil was obtained by hydro-distillation and the chemical composition of the leaf essential oil was analyzed using gas chromatography—mass *** mosquitoes were reared in the vector control laboratory and twenty lateⅢinstar larvae of three mosquito species were exposed to based on the wide range and narrow range tests,essential oil was tested at 50.100.150,200 and 250 ppm and each compound was tested at various concentration（5-75 ppm） and were assayed in the laboratory by using the protocol of WHO 2005:the 24 h LC50 values of the *** leaf essential oil and their major compounds were determined following Probit ***:The oil contained were mainlyβ-pinene（32.8%）,sabinene（28.3%）,germacrene-D（12.7%）,estragole （6.4%） and linalool（5.9%）.The essential oil from the leaves of *** exhibited significant larvicidal activity,with 24 h LC50 values of 140.96,130.19 and 119.59 *** five pure constituents extracted from the *** leaf essential oil were also tested individually against three mosquito *** LC50 values ofβ-pinene,sabinene,germacrene-D,estragole and linalool appeared to be most effective against Anopheles stephensi(LC50-23.17,19.67,16.95. 11.01,35.17 ppm) followed by Aedes aegypti(LC50-27.69,21.20,18.76,12.70,38.64 ppm) and Culex quinquefasciatus(LC50-32.23,25.***.21.28,14.01,42.28).Conclusions:The essential oil of C. anisata contains five major compounds and has remarkable larvicidal properties,which may be considered as a potent source for the production of natural larvicides.

关键词： Mosquito vectors Clausena anisata Essential oil GC-MS analysis Larvicidal activity

Larvicidal and repellent activities of Sida acuta Burm.F.(Family:Malvaceae) against three important vector mosquitoes

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Asian Pacific Journal of Tropical Medicine 2010年第9期3卷 691-695页

作者： marimuthu Govindarajan Division of Phytochemistry and Vector Biology Department of ZoologyAnnamalai UniversityAnnamalai Nagar-608 002India

Objective:To determine the larvicidal and repellent activities of Sida acuta Burm.F.（Family: Malvaceae）extract against Culex quinquefasciatus,Aedes aegypti and Anopheles stephensi. Methods:Twenty five late III instar larve of three mosquito species were exposed to various concentrations（15-90 mg/L） and were assayed in the laboratory by using the protocol of WHO 2005:the 24 h LC50 values of the Sida acuta leaf extract was determined following Probit analysis. The repellent efficacy was determined against three mosquito species at three concentrations viz.,1.0,2.5 and 5.0 mg/cm2 under the laboratory ***:Results showed varying degree of larvicidal activity of crude extract of Sida acuta against three important mosquitoes with LC50 values ranging between 38 to 48 mg/*** crude extract had strong repellent action against three species of mosquitoes as it provided 100%protection against Anopheles stephensi for 180 min followed by Aedes aegypti（150 min） and Culex quinquefasciatus（120 min）.Conclusions: From the results it can be concluded the crude extract of Sida acuta was an excellent potential for controlling Culex quinquefasciatus,Aedes aegypti and Anopleles stephensi mosquitoes.

关键词： Sida acuta Mosquito vectors Larvicidal activity Repellent activity

Frequency domain analysis of pre-stressed elastomeric vibration isolators

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Defence Technology（防务技术） 2023年第7期25卷 33-47页

作者： S.Somanath R.marimuthu Shankar krishnapillai Indian Space Research Organisation Anthariksh BhavanNew BEL RoadBengaluru560231India STR/VSSC Indian Space Research OrganisationThiruvananthapuram695022India Department of Mechanical Engineering IIT MadrasChennai600036India

Two types of elastomeric vibration isolators used for equipment vibration isolation in aerospace vehicles are considered for the present study. These isolators are constructed using elastomers mounted in steel encasings. These isolators are initially deformed statically and dynamic loads are applied on the deformed configuration. To capture the static deformation, equivalent static load corresponding to its load rating and specified displacements are created. Static deformation is computed using Finite Element methods with four node axi-symmetric element which include the geometric non-linear effect for steel and with standard Yeoh hyper-elastic material model for elastomers(Muhammed and Zu, 2012) [1]. Yeoh material constants are derived from uni-axial tension test data of the elastomer specimen. These isolators are subjected to harmonic and random excitations in the pre-deformed state. For numerical analysis, elastomeric constants at dynamic conditions are obtained as complex function of frequency using Dynamic Mechanical Analyzer(DMA) for a range of frequencies. The standard material model of Yeoh is modified incorporating frequency dependant material characteristics and damping in the range of frequencies of interest. A multiplicative non-separable variables law is derived for Yeoh material model to include the effect of static pre-stress, based on the methodology given in literature(Nashif et al.,1985;Beda et al., 2014) [2,3]. The modifications of Yeoh model suitable for frequency domain analysis is the novelty in the present study. In the analysis, while dynamic loads are applied, the configuration is updated considering initial static loading. The frequency response of the isolators is computed using material properties evaluated at progressive dynamic strains until a match in natural frequency is observed. Appropriate damping corrections are then incorporated to match the test observed transmissibility. Then updated material properties are used to compute the

关键词： Elastomer Isolator Axi-symmetric Frequency Random Response Strain amplitude Complex modulus Transmissibility

Mosquito adulticidal and repellent activities of botanical extracts against malarial vector,Anopheles stephensi Liston(Diptera:Culicidae)

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Asian Pacific Journal of Tropical Medicine 2011年第12期4卷 941-947页

作者： marimuthu Govindarajan Rajamohan Sivakumar Division of Vector Biology and Phytochemistry Department of ZoologyAnnamalai UniversityAnnamalai Nagar - 608 002Tamil NaduIndia

ObjectiveTo determine the adulticidal and repellent activities of different solvent leaf extracts of Eclipta alba (E. alba) and Andrographis paniculata (A. paniculata) against malarial vector, Anopheles stephensi (An. stephensi).MethodsAdulticidal efficacy of the crude leaf extracts of E. alba and A. paniculata with five different solvents like benzene, hexane, ethyl acetate, methanol and chloroform was tested against the five to six day old adult female mosquitoes of An. stephensi. The adult mortality was observed after 24 h under the laboratory conditions. The repellent efficacy was determined against An. stephensi mosquito species at three concentrations viz., 1.0, 2.5 and 5.0 mg/cm2 under laboratory conditions.ResultsAmong the tested solvents the maximum efficacy was observed in the methanol extract. The LC50 and LC90 values of E. alba and A. paniculata against adults of An. stephensi were 150.36, 130.19 ppm and 285.22, 244.16 ppm, respectively. No mortality was observed in controls. The chi-square values were significant at P<0.05 level. Methanol extract of E. alba and A. paniculata was produce maximum repellency against An. stephensi.ConclusionsFrom the results it can be concluded the crude extract of E. alba and A. paniculata was an excellent potential for controlling An. stephensi mosquitoes.

关键词： Adulticidal activity Repellent activity Anopheles stephensi Eclipta alba Andrographis paniculata

Atmospheric corrosion mapping of copper surfaces from diffuse light scattering measurements by an optoelectronic sensor system

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第4期10卷 613-618页

作者： marimuthu PAULVANNA NAYAkI Arunachalam P.kABILAN Department of Electronics and Communication Engineering PSNA College of Engineering and TechnologyDindigul 624622 India Department of Electronics and Communication Engineering Chettinad College of Engineering and TechnologyKarur 639114 India

A novel light scattering technique for mapping metal surface corrosion is presented and its results on copper exposed to atmosphere are reported. The front end of the instrument is made up of a sensor module comprising a thin beam light emitting diode (LED) illuminating a small spot on the metal surface, and a matched pair of photodetectors, one for capturing the reflected light and the other for sampling the scattered light. The analog photocurrent signals are digitized and processed online by a personal computer (PC) to determine the corrosion factor defined in terms of the two current values. By scanning the sample surface using the light beam and by computing the corrosion factor values simultaneously, a three dimensional graph and a two dimensional contour map are generated in the PC using Matlab tools. The values of the corrosion factor measured in different durations of exposure to atmosphere, which obey a bilogarithmic law, testify to the validity of our mathematical model.

关键词： Light scattering Optoelectronic sensor Atmospheric corrosion mapping

Prediction of performance, combustion and emission characteristics of diesel-thermal cracked cashew nut shell liquid blends using artificial neural network

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Frontiers in Energy 2016年第1期10卷 114-124页

作者： Arunachalam VELMURUGAN marimuthu LOGANATHAN E. James GUNASEkARAN Department of Mechanical Engineering Annamalai University Annamalainagar 608002 India

This paper explores the use of artificial neural networks （ANN） to predict performance, combustion and emissions of a single cylinder, four stroke stationary, diesel engine operated by thermal cracked cashew nut shell liquid （TC-CNSL） as the biodiesel blended with diesel. The tests were performed at three different injection timings （21°, 23°, 25℃A bTDC） by changing the thickness of the advance shim. The ANN was used to predict eight different engine-output responses, namely brake thermal efficiency （BTE）, brake specific fuel consumption （BSFC）, exhaust gas temperature （EGT）, carbon monoxide （CO）, oxide of nitrogen （NOx）, hydrocarbon （HC）, maximum pressure （Pm~,,） and heat release rate （HRR）. Four pertinent engine operating parameters, i.e., injection timing （IT）, injection pressure （IP）, blend percentage and pecentage load were used as the input parameters for this modeling work. The ANN results show that there is a good correlation between the ANN predicted values and the experimental values for various engine performances, combustion parameters and exhaust emission characteristics. The mean square error value （MSE） is 0.005621 and the regression value ofR2 is 0.99316 for training, 0.98812 for validation, 0.9841 for testing while the overall value is 0.99173. Thus the developed ANN model is fairly powerful for predicting the performance, combustion and exhaust emissions of internal combustion engines.

关键词： cashew nut shell liquid (CNSL) artificialneural networks (ANN) thermal cracking mean squareerror (MSE)