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Frontiers of Materials Science 2013年第2期7卷 196-201页

作者： R. ELILARASSI G. chandrasekaran Magnetism and Nanomagnetic Materials Lab Department of Physics School of Physical Chemical and Applied Sciences Pondicherry University Puducherry 605014 India

Nanocrystalline Zn1_xCuxO （x = 0, 0.02, 0.04, 0.06, 0.08） samples were synthesized by a novel auto-combustion method using glycine as the fuel material. The structural, optical and magnetic properties of the samples were characterized using XRD, SEM, photoluminescence （PL） and electron paramagnetic resonance （EPR） spectro- scopies. The XRD spectra of samples reveal the hexagonal wurtzite structures of ZnO. As the copper content increases, a diffraction peak at 28 = 39° corresponding to secondary phase of CuO （[111] crystalline face） appears when x≤ 6 mol.%. PL spectra of the samples show a strong ultraviolet （UV） emission and defect related visible emissions. Cu-doping in ZnO can effectively adjust the energy level in ZnO, which leads to red shift in the emission peak position in UV region. The EPR spectra of Cu-doped ZnO nanoparticles show a distinct and broad signal at room temperature, suggesting that it may be attributed to the exchange interactions within Cu2＋ ions.

关键词： Cu-doped ZnO auto-combustion luminescence electron paramagneticresonance (EPR)

Screening,phylogenetic analysis and antibiotic sensitivity pattern of Salmonella enterica serovar Typhi isolates from typhoid asymptomatic carriers

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Asian Pacific Journal of Tropical Medicine 2011年第10期4卷 769-772页

作者： Balaji chandrasekaran Senthilkumar Balakrishnan Centre for Biotechnology Muthayammal College of Arts & ScienceRasipuram-637408Tamil NaduIndia

Objective:To isolate the Salmonella enterica serovar Typhi(***) from asymptomatic typhoid carriers in the local *** assess the antibiotic sensitivity and resistant pattern of *** isolates against viable antibiotics and phylogenetic analysis of *** isolates on the basis of 16S rDNA ***:*** was isolated and identified based on the cultural characteristics on BSA(Bismuth Sulphite Agar),MacConkey agar,agglutination test with specific antiserum and phylogenetic *** isolates were tested for sensitivity and resistant pattern with a number of viable antibiotics by disc diffusion ***:A total of 15 bile samples were collected from the food handlers to screen the typhoid asymptomatic *** result was yielded for 3 out of 15 *** isolates showed resistant to amphicillin(100%), tetracyclin(100%),rifampicin(66.5%),ofloxacin(33.5%),cloxacillin(33.5%) and susceptibility to gentamycin(100%),amikacin(100%),chloramphenicol(100%),streptomycin(100%),kanamycin (100%),cprofloxacin(100%),amoxycillin(66.5%) and ofloxacin(66.5%).Conclusions:This study demonstrates the outbreak of typhoid fever occurs through asymptomatic *** addition,this study also reveals the occurrence of considerable drug resistant among the *** isolates.

关键词： Asymptomatic typhoid carriers Antibiotics Phylogeny

In situ formation of bimetallic FeNi nanoparticles on sand through green technology:Application for tetracycline removal

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Frontiers of Environmental Science & Engineering 2020年第1期14卷 185-197页

作者： Ravikumar KVG Debayan Ghosh M rudula Pulimi chandrasekaran Natarajan Amitava Mukherjee Centre for Nanobiotechnology VITVelloreTamil NaduIndia

In this study,FeNi nanoparticles were green synthesized using Punica granatum(pomegranate)peel extract,and these nanoparticles were also formed in situ over quartz sand(GS-FeNi)for removal of tetracycline(TC).Under the optimized operating conditions,(GS-FeNi concentration:1.5%w/v;concentration of TC:20 mg/L;interaction period:180 min),99±0.2%TC removal was achieved in the batch reactor The removaT capacity was 181±1 mg/g.A detailed characterization of the sorbent and the solution before and after the interaction revealed that the removal mechanism(s)involved both the sorption and degradation of *** reusability of reactant was assessed for four cycles of operation,and 77±4%of TC removal was obtained in the *** judge the environmental sustainability of the process,residual toxicity assay of the interacted TC solution was performed with indicator bacteria(Bacillus and Pseudomonas)and algae(Chlorella sp.),which confirmed a substantial decrease in the *** continuous column studies were undertaken in the packed bed reactors using *** the optimized conditions,quite high removal efficiency(978±5 mg/g)was obtained in the *** application of GS-FeNi for antibiotic removal was further evaluated in lake water,tap water,and ground water spiked with TC,and the removal capacity achieved was found to be 781±5,712±5,and 687±3 mg/g,*** work can pave the way for treatment of antibiotics and other pollutants in the reactors using novel green composites prepared from fruit wastes.

关键词： GS-FeNi nanoparticles Tetracycline removal Re-usability Residual toxicity Column studies

Structural Health Monitoring of Offshore Buoyant Leg Storage and Regasification Platform:Experimental Investigations

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Journal of Marine Science and Application 2018年第1期17卷 87-100页

作者： Srinivasan chandrasekaran Thailammai Chithambaram Department of Ocean Engineering IIT MadrasChennaiTamil Nadu 600036India

Offshore platforms are of high strategic importance,whose preventive maintenance is on top *** Leg Storage and Regasification Platforms(BLSRP)are special of its kind as they handle LNG storage and processing,which are highly *** of structural health monitoring(SHM)to offshore platforms ensures safe operability and structural *** damages on the offshore platforms under rare events can be readily identified by deploying dense array of sensors.A novel scheme of deploying wireless sensor network is experimentally investigated on an offshore BLSRP,including postulated failure modes that arise from tether *** of the scaled model under wave loads is acquired by both wired and wireless sensors to validate the proposed *** wireless sensor network is used to trigger alert monitoring to communicate the unwarranted response of the deck and buoyant legs under the postulated failure *** triggers the alert mechanisms on exceedance of the measured data with that of the preset threshold values;alert mechanisms used in the present study include email alert and message pop-up to the validated user *** study is a prima facie of SHM application to offshore platforms,successfully demonstrated in lab scale.

关键词： Wireless sensor network Structural health monitoring Condition-based monitoring Response analysis Alert Monitoring System Underwater sensors Postulated failure

Temporal gradients limit the accumulation of neutrophils toward sources of chemoattractant

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Microsystems & Nanoengineering 2017年第1期3卷 455-462页

作者： Arvind chandrasekaran Felix Ellett Julianne Jorgensen Daniel Irimia Department of Surgery BioMEMS Resource CenterMassachusetts General HospitalHarvard Medical SchoolShriners Burns HospitalBostonMA 02129USA

Neutrophil trafficking during inflammation is a highly orchestrated process,coordinating neutrophil recruitment,sterilization of the wound,and inflammation *** the chemotactic signals guiding neutrophil recruitment to sites of inflammation are relatively well understood,our knowledge of mechanisms controlling cessation of neutrophil recruitment and return to normal tissue physiology remains *** gain insights into these processes,we designed a microfluidic device with an array of chemoattractant reservoirs,which mimics the microenvironment in infected tissues,when multiple clusters of microbes are *** monitored the temporal dynamics of neutrophil recruitment toward the chemoattractant reservoirs at single cell resolution,for 3 *** observed robust neutrophil recruitment that reached a plateau after 1.5 h,despite the continuous presence of strong chemoattractant gradients around the *** timing of the plateau was dependent on the geometry of the devices and was independent from the number of *** the basis of these observations,we ruled out sub-population sensitivity,chemoattractant scavenging,and production of a self-limiting stop signal as potential mechanisms underpinning the plateau in neutrophil *** found a strong correlation between the temporal stabilization of concentration changes and the plateau in neutrophils *** results suggest that dynamic aspects of chemoattractant gradients are key for maximizing recruitment during the acute phase of infections and limiting the accumulation of neutrophils as soon as the infection is contained.

关键词： chemotaxis leukocyte microfluidic relay signaling scavenging

Optimization and modeling studies on the production of a new fibrinolytic protease using Streptomyces radiopugnans_VITSD8

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Frontiers in Biology 2018年第1期13卷 70-77页

作者： Dhamodharan Duraikannu Subathra Devi chandrasekaran School of Biosciences and Technology VIT University Vellore Tamil Nadu lndia

BACKGROUND： The current study demonstrated the possibility of statistical design tools combination with computational tools for optimization of fermentation conditions for enhanced fibrinolytic protease production. METHODS： The effects of using different carbon and nitrogen sources for protease production by Streptomyces radiopugnans_VITSD8 were examined by a full factorial design method. The incubation time, temperature, pH of the medium, and RPM were assessed by the predictable one factor at a time （OFAT） method. Optimization was carried out using starch and oat meal as carbon source, nitrogen source as peptic and malt extract using Fractional Factorial Design （FFD）. The analysis was further continued for medium volume, temperature, initial medium pH, inoculum concentration, high determination co-efficient as （R＇-0.965）, and lower determination co-efficient of variation （CV-8.19%）, which defines a reliable and accurate experimental value. RESULTS： Analysis of variance by the fixed slope effect by temperature and starch; temperature and L-aspargine, temperature and oat meal, temperature and peptic extracts, temperature and pH, temperature and duration of incubation were more vital for protease production at an interactive level. Response surface plots revealed that temperature, starch, and peptic extracts affix critical concerning in temperature. Programming estimated a 28% increase in protease production. Incubation temperature and medium volume portrayed extreme impact among all factor. Starch, peptic and temperature play an important regulatory role in protease production. Optimium temperature for protease production was 33~C. The ratio of carbon and nitrogen sources and pH were the major regulatory factors in protease production by Streptomyces radiopugnans_VITSD8. It demonstrated a 4% noteworthy change in condition. CONCLUSION： Among all the selected parameters, temperature was the most intuitive factor, demonstrating a notable connection with the type of medi

关键词： Protease Streptomyces radiopugnans_VITSD8 Full Factorial design (FFD) fermentation optimization RSM

Synthesis and optical properties of Ni-doped zinc oxide nanoparticles for optoelectronic applications

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Optoelectronics Letters 2010年第1期6卷 6-10页

作者： R.Elilarassi G.chandrasekaran Department of Physics School of PhysicalChemical and Applied SciencesPondicherry University

Nanocrystalline undoped and nickel doped zinc oxide (Zn1-xNixO, x=0.00, 0.01) powders are successfully synthesized by a simple and low-temperature "auto-combustion method". The microstructural and optical absorption and emission properties of the as-prepared samples are obtained using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infra-red spectrometer (FTIR), UV-visible and photoluminescence (PL). The structure study confirms the formation of the hexagonal wurtzite ZnO without any secondary phase in the Ni-doped sample. The optical absorption measurements indicate the red shift in the absorption band edge upon nickel doping. The band gap energy decreases from 3.21 eV to 3.17 eV. The photoluminescence spectra of the as-prepared samples under a room temperature show strong ultraviolet (UV) and blue emission peaks. The PL emission research strongly reveals that Ni doping can effectively adjust the energy level which leads to a red shift at the emission peak in UV region.

关键词：纳米掺杂氧化物傅立叶变换红外光谱仪锌镍光电应用光学性质合成扫描电子显微镜

Assessing combined toxic effects of tetracycline and P25 titanium dioxide nanoparticles using Allium cepa bioassay

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Frontiers of Environmental Science & Engineering 2021年第1期15卷 101-112页

作者： Barsha Roy Khushboo Kadam Suresh Palamadai Krishnan chandrasekaran Natarajan Amitava Mukherjee School of Biosciences and Technology VITVellore 632014India Centre for Nanobiotechnology VITVellore 632014India

Usage of titanium dioxide nanoparticles(TiO_(2) NPs)and tetracycline(TC)has increased significantly in the present *** leads to their release and accumulation in the *** the compounds,individually,can have adverse toxic effects on the *** binary mixtures can increase this degree of *** present study aimed to evaluate the toxicity of both the contaminants in individual and binary mixtures in Allium ***,the toxicity of TiO_(2) NPs upon UVA pre-irradiation was also *** showed that UVA pre-irradiated NPs(UVA-TiO_(2) NPs)had a significant decrease in cell viability than their non-irradiated counterparts(NI-TiO_(2)),denoting an increase in photocatalytic activity upon UVA *** low concentrations of TC(EC10=0.016µmol/L)mixed with TiO2 NPs significantly increased the toxicity for both UVA-TiO_(2) and NI-TiO_(2) *** ROS generation was significantly high for UVA-TiO_(2) ***,TC did not have any effects on ROS *** the compounds exhibited genotoxic potential in *** chromosomal abnormalities like anaphase bridges,telophase bridges,laggard chromosomes,binucleate cells,*** *** binary mixture of UVA-TiO_(2) NPs and TC showed the highest chromosomal aberrations(64.0%±1.26%)than the mixture with NI-TiO_(2) or the individual *** decreased significantly after recovery(46.8%±1.92%),denoting the self-repair *** study proved that UVA-TiO2 NPs were more toxic and could be enhanced further when mixed with a sub-lethal concentration of *** work will help to assess the risk of both compounds in the environment.

关键词： Binary toxicity Cell viability Mitotic index Chromosomal aberration Reactive oxygen species Nanoparticles internalization

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Network Traffic Prediction Using Radial Kernelized-Tversky Indexes-Based Multilayer Classifier

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Computer Systems Science & Engineering 2022年第3期40卷 851-863页

作者： M.Govindarajan V.chandrasekaran S.Anitha Department of Computer Applications Velalar College of Engineering and TechnologyErode638012India Department of Electronics and Communication Engineering Velalar College of Engineering and TechnologyErode638012India Department of Information Technology Kongu Engineering CollegePerunduraiIndia

Accurate cellular network traffic prediction is a crucial task to access Internet services for various devices at any *** the use of mobile devices,communication services generate numerous data for every *** the increasing dense population of data,traffic learning and prediction are the main components to substantially enhance the effectiveness of demand-aware resource allocation.A novel deep learning technique called radial kernelized LSTM-based connectionist Tversky multilayer deep structure learning(RKLSTM-CTMDSL)model is introduced for traffic prediction with superior accuracy and minimal time *** RKLSTM-CTMDSL model performs attribute selection and classification processes for cellular traffic *** this model,the connectionist Tversky multilayer deep structure learning includes multiple layers for traffic prediction.A large volume of spatial-temporal data are considered as an input-to-input ***,input data are transmitted to hidden layer 1,where a radial kernelized long short-term memory architecture is designed for the relevant attribute selection using activation function *** obtaining the relevant attributes,the selected attributes are given to the next *** index function is used in this layer to compute similarities among the training and testing traffic *** similarity index outcomes are given to the output *** value is used as basis to classify data as heavy network or normal ***,cellular network traffic prediction is presented with minimal error rate using the RKLSTM-CTMDSL *** evaluation proved that the RKLSTM-CTMDSL model outperforms conventional methods.

关键词： Cellular network traffic prediction connectionist Tversky multilayer deep structure learning attribute selection classification radial kernelized long short-term memory

Synthesis and characterization of ball milled Fe-doped ZnO diluted magnetic semiconductor

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Optoelectronics Letters 2012年第2期8卷 109-112页

作者： R.Elilarassi G.chandrasekaran Magnetism and Nanomagnetic Materials Lab Department of Physics School of Physical Chemical and Applied Sciences Pondicherry University

Fe-doped ZnO (Zn0.99Fe0.01O) powders are successfully prepared by ball milling with different milling time, and are inves- tigated using X-ray diffraction (XRD), scanning electron microscope (SEM), ultraviolet-visible (UV-VIS) spectroscopy, vibrating sample magnetometer (VSM) and electron paramagnetic resonance (EPR) spectroscopy. The structural analysis using XRD reveals that the Fe-doped ZnO milled at different milling time can crystallize in a wurtzite structure, and in the XRD patterns, the secondary phase related to Fe cluster with the sensitivity of the XRD instrument can not be found. The SEM image of the sample milled for 24 h shows the presence of spherical nanoparticles. From the optical analysis, the optical band gap is found to decrease with increasing the milling time, which indicates the incorporation of Fe2+ ions into the ZnO lattice. The magnetization measurement using VSM reveals that the nanoparticles exhibit ferromagnetic behavior at room temperature, and the magnetization increases gradually with increasing the milling time. The conclusion is further confirmed by the electron paramagnetic resonance of the nanoparticles examined at room temperature, which shows an intense and broad ferromagnetic resonance signal related to Fe ions.

关键词：球磨时间铁掺杂 ZnO 稀磁半导体振动样品磁强计电子顺磁共振 X射线衍射扫描电子显微镜