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Effect of Lithium Doping on the Properties L-Citrulline Oxalate Monohydrate Nonlinear Optical Crystals

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Open Journal of Metal 2012年第4期2卷 82-86页

作者： Vallath govindan Sreevalsa Sankaran Jayalekshmi Division for Research in Advanced Materials Department of Physics Cochin University of Science and Technology Cochi India

Single crystals of pure and Li+ doped L-citrulline oxalate (LCO) crystals are grown successfully by slow evaporation technique. The effect of lithium doping on crystal properties has been studied. The samples are characterized by X-ray powder diffraction, TGA, FTIR, Raman and UV-Vis spectroscopic techniques. The presence of lithium in Li+ doped LCO crystals is estimated using AES. The thermal stability and the optical transparency region are found to be enhanced for the doped samples. The second harmonic generation efficiency of the doped crystal has improved considerably compared to pure L-citrulline oxalate. Lithium doping can hence be considered as a simple and advantageous technique to improve the thermal, optical and non linear optical (NLO) properties of the LCO single crystals.

关键词： Doping X-Ray Diffraction Growth from Solutions Single Crystal Growth Nonlinear Optic Material

Application of Taguchi’s Orthogonal Array in Multi Response Optimization of NO<sub>x</sub>Emission of Crude Rice Bran Oil Methyl Ester Blend as a CI Engine Fuel

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Open Journal of Optimization 2012年第2期1卷 25-33页

作者： Subramani Saravanan govindan Nagarajan Santhanam Sampath Department of Automobile Engineering Rajalakshmi Engineering College Thandalam India Department of Automobile Engineering Sri Venkateswara College of Engineering Sriperumbudur India Department of Mechanical Engineering College of Engineering Anna University Chennai India

In this work an attempt was made to minimize the NOx emission of a crude rice bran oil methyl ester (CRBME) blend with less sacrifice on smoke density and brake thermal efficiency. Three factors namely fuel injection timing, percentage EGR and fuel injection pressure were chosen as the influencing factors for the set objective. Experiments were designed by employing design of experiments method and Taguchi’s L9 orthogonal array was used to test the engine. MRSN ratio was calculated for the response variables and the optimum combination level of factors was obtained simultaneously using Taguchi’s parametric design. ANOVA was employed to analyze the variance of MRSN and the most influencing factor for the set objective was taken from the ANOVA table. Obtained combination was confirmed experimentally and significant improvement was observed in the response variables.

关键词： Diesel Engine Emission Crude Rice Bran Oil Biodiesel Taguchi’s Orthogonal Array MRSN DOE

Reconfigurable Ultrasonic Testing System Development Using Programmable Analog Front-End and Reconfigurable System-on-Chip Hardware

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Circuits and Systems 2015年第7期6卷 161-171页

作者： Pramod govindan Vidya Vasudevan Thomas Gonnot Jafar Saniie Department of Electrical and Computer Engineering Illinois Institute of Technology Chicago IL USA

Ultrasonic testing systems have been extensively used in medical imaging and non-destructive testing applications. Generally, these systems aim at a particular application or target material. To make these systems portable and more adaptable to the test environments, this study presents a reconfigurable ultrasonic testing system (RUTS), which possesses dynamic reconfiguration capabilities. RUTS consists a fully programmable Analog Front-End (AFE), which facilitates beamforming and signal conditioning for variety of applications. RUTS AFE supports up to 8 transducers for phased-array implementation. Xilinx Zynq System-on-Chip (SoC) based Zedboard provides the back-end processing of RUTS. The powerful ARM embedded processor available within Zynq SoC manages the ultrasonic data acquisition/processing and overall system control, which makes RUTS a unique platform for the ultrasonic researchers to experiment and evaluate a wide range of real-time ultrasonic signal processing applications. This Linux-based system is utilized for ultra-sonic data compression implementation providing a versatile environment for further development of ultrasonic imaging and testing system. Furthermore, this study demonstrates the capabilities of RUTS by performing ultrasonic data acquisition and data compression in real-time. Thus, this reconfigurable system enables ultrasonic designers and researchers to efficiently prototype different experiments and to incorporate and analyze high performance ultrasonic signal and image processing algorithms.

关键词： Dynamic Reconfiguration System-on-Chip Analog Front-End Ultrasonic Imaging

Incidental gall bladder cancers:Are they truly incidental?

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World Journal of Gastrointestinal Oncology 2014年第12期6卷 441-443页

作者： Ashwin Rammohan Sathya D Cherukuri Jeswanth Sathyanesan Ravichandran Palaniappan Manoharan govindan The Institute of Surgical Gastroenterology and Liver Transplantation Centre for GI Bleed Division of HPB diseases Stanley Medical College Hospital Stanley Medical College Hospital

AIM: To seek and analyze features suggestive of gallbladder cancer(GBC) on preoperative imaging and intraoperative findings in patients diagnosed as having incidental GBC(IGBC). METHODS: The study was conducted on 79 patients of IGBC managed in our department over a 10-year period(2003-2012). Review of preoperative imaging and operative notes was done to ascertain any suspicion of ***: Of the 79 patients, Ultrasound abdomen showed diffuse thickening, not suspicious of malignancy in 5 patients, and diffuse suspicious thickening was seen in 4 patients. Focal thickening suspicious of malignancy was present in 24 patients. Preoperative computed tomography/magnetic resonance imaging was done in 9 patients for suspicion of malignancy. In 5 patients, dif-ficult Cholecystectomy was encountered due to dense/inflammatory adhesions. Intraoperative findings showed focal thickening of the gallbladder and a gallbladder mass in 9 and 17 patients respectively. On overall analysis, 37 patients had preoperative imaging or intraoperative findings suggestive of malignancy, which was either a missed GBC or an unsuspected/unexpected GBC. In 42(53.2%) patients, there was no evidence suggestive of malignancy and was an unanticipated ***: Our study highlights a potential and not-so-rare pitfall of Laparoscopic Cholecystectomy. A greater awareness of this clinical entity along with a high index of suspicion and a low threshold for conversion to open procedure, especially in endemic areas may avert avoidable patient morbidity and mortality.

关键词： Incidental gallbladder cancer Preoperative detection Imaging

Microscopy Method to Compare Cyst Nematode Infection of Different Plant Species

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Advances in Bioscience and Biotechnology 2016年第6期7卷 311-318页

作者： Rinu Kooliyottil Louise-Marie Dandurand Byju N. govindan Guy R. Knudsen Department of Plant Soil and Entomological Sciences University of Idaho Moscow ID USA Biological Systems Engineering Washington State University Pullman WA USA

The cyst nematode, Globodera pallida, is an obligate, biotrophic pathogen of potato, causing up to 80% yield loss. In the present study, a non-destructive imaging technique was used to compare the development and behavior of G. pallida in its host Solanum tuberosum and in the non-host S. sisymbriifolium. We used microscopy-rhizosphere chambers coupled with the fluorescent stain PKH26, and compared this with destructively sampled acid fuchsin staining. No significant difference (P ≥ 0.90) in G. pallida numbers was found whether stained with PKH26 or acid fuchsin for either plant species indicating no toxic effect from the vital stain. PKH26 labelled J2s successfully located and penetrated roots of both S. tuberosum and S. sisymbriifolium. Two days after inoculation, PKH26 stained G. pallida was clearly observed migrating intercellularly through root tissues of both S. tuberosum and the non-host S. sisymbriifolium. Overall, more nematodes were observed in S. tuberosum than in S. sisymbriifolium roots. No live J2s were observed in S. sisymbriifolium roots stained with either acid fuchsin or PKH26 after 8 days. Understanding the time line of development of G. pallida in S. sisymbriifolium is important towards comprehensive understanding of plant defense responses.

关键词： Cyst Nematode Solanum sisymbriifolium Non-Destructive Imaging

Customized Prediction of Short Length of Stay Following Elective Cardiac Surgery in Elderly Patients Using a Genetic Algorithm

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World Journal of Cardiovascular Surgery 2013年第5期3卷 163-170页

作者： Joon Lee Sapna govindan Leo A. Celi Kamal R. Khabbaz Balachundhar Subramaniam Beth Israel Deaconess Medical Center Boston USA Harvard-MIT Division of Health Sciences and Technology Cambridge USA School of Public Health and Health Systems University of Waterloo Waterloo Canada

Objective: To develop a customized short LOS (gery, using local data and a computational feature selection algorithm. Design: Utilization of a machine learning algorithm in a prospectively collected STS database consisting of patients who received cardiac surgery between January 2002 and June 2011. Setting: Urban tertiary-care center. Participants: Geriatric patients aged 70 years or older at the time of cardiac surgery. Interventions: None. Measurements and Main Results: Predefined morbidity and mortality events were collected from the STS database. 23 clinically relevant predictors were investigated for short LOS prediction with a genetic algorithm (GenAlg) in 1426 patients. Due to the absence of an STS model for their particular surgery type, STS risk scores were unavailable for 771 patients. STS prediction achieved an AUC of 0.629 while the GenAlg achieved AUCs of 0.573 (in those with STS scores) and 0.691 (in those without STS scores). Among the patients with STS scores, the GenAlg features significantly associated with shorter LOS were absence of congestive heart failure (CHF) (OR = 0.59, p = 0.04), aortic valve procedure (OR = 1.54, p = 0.04), and shorter cross clamp time (OR = 0.99, p = 0.004). In those without STS prediction, short LOS was significantly correlated with younger age (OR = 0.93, p 0.001), absence of CHF (OR = 0.53, p = 0.007), no preoperative use of beta blockers (OR = 0.66, p = 0.03), and shorter cross clamp time (OR = 0.99, p 0.001). Conclusion: While the GenAlg-based models did not outperform STS prediction for patients with STS risk scores, our local-data-driven approach reliably predicted short LOS for cardiac surgery types that do not allow STS risk calculation. We advocate that each institution with sufficient observational data should build their own cardiac surgery risk models.

关键词： Cardiac Surgery Elderly Length of Stay Risk Prediction Genetic Algorithm

Studies on in-vitro antioxidant activity of marine edible seaweeds from the east coastal region of Peninsular Malaysia using different extraction methods

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Journal of Coastal Life Medicine 2013年第3期 193-198页

作者： Tam Siow Foon Lian Ai Ai Palaniselvam Kuppusamy Mashitah M.Yusoff Natanamurugaraj govindan Biomaterial and Biosensor laboratory Faculty of Industrial Sciences and TechnologyUniversiti Malaysia PahangLebuhraya Tun Razak 26300GambangKuantanPahangMalaysia

Objective:To determine the antioxidant activity of two edible marine seaweeds Eucheumacottonii and Padina sp..Methods:The two extraction methods such as conventional and soxhlet extraction were used to isolate the secondary metabolites using methanol as a solvent *** phenolic content of crude seaweeds extract were analysed by standard FC *** different antioxidant assays DPPH,ferric reducing antioxidant power and β-carotene bleaching assays confirmed the antioxidant ***:with expressed higher total phenolic content in the seaweeds *** β-carotene bleaching assay lower activity compare with BHT as reference *** IR spectra showed the phenolic related functional groups are present in the solvent *** phenolic related compounds are mainly responsible for higher rate of antioxidant ***:DPPH and ferric reducing antioxidant power assays showed the positive correlation higher phenolic contents than the Eucheuma *** also the soxhlet extraction showed higher yield and better radical scavenging activity compared to conventional *** the studies confirmed both seaweeds are an effective candidate for the control the free radical scavenging activity.

关键词： Antioxidant activity DPPH Different extraction Marine seaweeds

“科学促进社会变革”:喀拉拉邦的科学和文化

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科学与社会 1990年第3期 51-58页

作者： govindan Parayil 金同超布莱克斯堡弗吉尼亚工艺学院

在印度喀拉拉邦,由于喀拉拉邦科学普及协会(KSSP)发起一项举世无双的社会运动,使成千上万的人定期参加科学普及活动。这一运动的组织者采用别具一格而且往往是丰富多采的方法,将科学技术引入城乡居民的日常生活,并积极开展环境保护运动。

关键词： SSP 志愿人员组织者印度社会变革南亚喀拉拉邦

Induction of bioactive compound composition from marine microalgae(Lyngbya sp.)by using different stress condition

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Journal of Coastal Life Medicine 2013年第3期 205-209页

作者： Nurul Farhana Rosly Rabeah Adawiyah Abdul Razak Palaniselvam Kuppusamy Mashitah M.Yusoff Natanamurugaraj govindan Mammalian Cell Technology Laboratory Faculty of Industrial Sciences and TechnologyUniversiti Malaysia PahangLebuhraya Tun Razak26300 GambangKuantanPahangMalaysia

Objective:To the effect of salinity stress on the production of microalgae(Lyngbya sp.)and chlorophyll pigments in the growth ***:Stress was investigated by using green algae strains Lyngbya *** response to change bioactive compounds without any modification of cell growth and biomass production *** different stress conditions like 10%-40%were ***:During the stress condition,various biochemical and microbiological assays were *** photochemical composition was evaluated by GC-MS *** studies expressed that 30%higher salinity stress was suitable for high phytochemical production rate including chlorophyll ***:Our study indicates the wide range of salinity stress to enhance the growth on microalgae culture and enhance the production of major secondary metabolites.

关键词： Lyngbya Sp. Salinity stress Secondary metabolites Biomass Chlorophyll