Informatics Publishing Limited

S. Krishnakumar , V. S. Geetha , A. Kuruvilla

Abstract

Objective: (1) To evaluate the local anesthetic activity of betel leaf and assess the effect of betel nut on such effect and (2) to observe local anesthetic activity after autoclaving the extracts of betel leaf. Materials and methods: Extracts of plain betel leaf with betel nut, with and without autoclaving, were tested for surface and infiltration anesthetic activities using rabbits and guines pigs. The results were compared with normal saline control and xylocaine drug control. Results: Betel leaf showed dose-dependant infiltration anesthetic activity comparable with xylocaine. As a surface anesthetic, the onset was as quick as xylocaine and the duration was shorter than xylocaine. Betel nut significantly reduced the infiltration activity and abolished the surface anesthetic activity of betel leaf. Autoclaving did not result in any loss of activity. Conclusion: Betel leaf has potent local anesthetic action both by surface and infiltration techniques. This effect is reduced by the addition of betel nut but not lost on autoclaving.

Keywords

Piper Betel, Areca Catechu, Local Anesthetic Activity

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S. Krishnakumar ¹, R. Alexis Rajan ², M. Michael Babu ², V. Dooslin Mercy Bai ³

Affiliations
1 Department of Biomedical Engineering, Sathyabama University, Chennai - 600 119, Tamil Nadu, IN
2 Center for Marine Science and Technology, Manonmaniam Sundaranar University, Rajakkamangalam - 629 501, Tamil Nadu, IN
3 Department of Biomedical Engineering, Rajiv Ganthi College of Enginnering and Technology,Puducherry - 607402, IN

Abstract

Extended spectrum of beta lactamase (ESBL) producing organisms create a major problem in clinical therapeutics. Antimicrobial resistant pattern of uropathogens were isolated from Government hospital, Thiruvanamalai district, Tamilnadu, India, during the period of January to June 2008. Total of 54 ESBL producing clinical isolates of gram negative bacilli were obtained from urine samples of 50 pregnant women. ESBL producers were detected of which 24(44.4%) isolates were E.coli, 20(37%) isolates were K.pneumoniae and 10(18.5%) isolates were P. aeruginosa. Out of 54 isolates 57.4%, 46.6% and 33.3% were resistant to Ampicillin, Amoxycillin and Ceftriaxone respectively. Of all isolates 100% susceptible to Ampicillin, Amoxycillin and Ceftriaxone combined with sulbactum and clavulanic acid showed synergistic effect. These combined drugs were found to be the choice for UTI infection to pregnant women. This study shows the frequency of drug resistant and ESBL producing E. coli, K. pneumoniae and P.aeruginosa is high in pregnant women. Advance drug resistance surveillance of ESBL isolates is need for perceptive use of antimicrobial agents.

Keywords

Uropathogens, UTI, ESBL, Antimicrobial Susceptibility, Drug Resistant

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S. Krishnakumar ¹, N. Singaravelu ¹, C. Kumaravelu ¹, S. Suresh ¹

Affiliations
1 Combat Vehicles Research and Development Establishment, Defence Research and Development Organization, Ministry of Defence, Avadi, Chennai-600054, IN

Abstract

This paper details the air flow characteristics of the louvers of air intake system in armour fighting vehicles. An attempt is made to optimize the louver configuration to meet the requirements of protection and Airflow characteristics without increasing the vehicle volume and with modifications wherever possible. Pressure drop tests on S type of louvers were undertaken in the existing air intake system of Armour Fighting Vehicles for various configurations.

Keywords

Armour Fighting Vehicle, Louvers, Air Intake System, Air Filters, Pressure Drop.

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R. Rohith Krishnan ¹, S. Krishnakumar ¹

Affiliations
1 Department of Electronics, School of Technology and Applied Sciences, M. G. University Regional Centre, Edappally, Ernakulam - 682024, Kerala, IN

Abstract

Network theorems or circuit theorems are special aids, which can reduce the amount of effort involved in circuit analysis to a considerable degree. For linear networks, there exists interdependence between various network theorems. Thus, by careful analysis, one theorem can verify in terms of another theorem and it is advantageous for pedagogical reasons. A scheme for analogue circuit analysis is presented in this paper. Here piece-by-piece or part-by-part analyzing strategy is employed which can reduce the complexity associated with analyzing or biasing design of large analogue circuits. Fixatornorator pair plays the key role in this methodology. Hybrid equivalent circuit, an alternative for Thevenin’s or Norton’s equivalent model is realized with fixator-norator pair, and is seen to be more dynamic and flexible since it contains both voltage source and current source. Thevenin’s theorem, compensation theorem and maximum power transfer theorem are analyzed in terms of fixator norator pairs, and the study indicates the importance and capabilities of fixator-norator pair and hence hybrid equivalent circuit in analogue circuit design and analysis.

Keywords

Compensation Theorem, Fixator-norator Pair, Hybrid Equivalent Circuit, Maximum Power Transfer Theorem, Thevenin’s Theorem.

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K. M. Jeevan ¹, S. Krishnakumar ¹

Affiliations
1 School of Technology and Applied Sciences, Mahatma Gandhi University Regional Centre, IN

Abstract

Human Visual System (HVS) is for acquiring, processing, analyzing, and understanding the images and this is a natural process. The image acquisition, processing, analysing and understanding the images are electronically duplicated in Computer vision. At present the hardware available for acquiring, processing and displaying is based on square pixel. But, retina of the human eye closely resembles a hexagonal grid space. So if we could able to represent the image in hexagonal domain, the computer vision will be as close to human vision. Keeping this in mind, we proposed a wavelet based image de-noising on hexagonally re-sampled images. In addition to the biological inspiration the hexagonal representation has many other advantages. By considering these advantages of hexagonal representation, in this work we proposed a wavelet based image denoising scheme in hexagonal grid space. For analysing and comparing result obtained in hexagonal grid with square grid image, Mean Square Error (MSE) and Peak Signal to Noise Ratio (PSNR) is used.

Keywords

Gabor Filter, Wavelets, Interpolation, Hexagonal Grid.

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T. N. Tilak ¹, S. Krishnakumar ¹

Affiliations
1 School of Technology and Applied Sciences, Mahatma Gandhi University Regional Center,Changampuzha Samadhi Road, Devankulangara, Palarivattom, Ernakulam, Kochi – 682024, Kerala, IN

Abstract

Objectives: This is to investigate the performance of two orthogonal, compactly supported, near symmetric wavelet families’ viz., coiflets and symlets in denoising satellite images. Methods/Statistical Analysis: We use the Stationary Wavelet Transform (SWT) which is a shift-invariant transform and three levels of image decomposition. Additive White Gaussian Noise (AWGN) is used to produce the corrupted images used for the study. Findings: The study identified the most suitable wavelet in each of the above two wavelet families, for denoising satellite images. A comparison between the denoising performances of these wavelet families has also been made. It has been found that the denoising performance of wavelets belonging to both the families decrease as the wavelet order increases. Applications/Improvements: The study finds application in the denoising of satellite images and images obtained by space exploration and such images corrupted by a combination of several types of noise distributions.

Keywords

Compact Support, Denoising, Gaussian, Near-Symmetry, Orthogonal

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S. Krishnakumar ¹, R. Divya ¹, N. R. Kanchana Devi ¹, G. Keerthana ¹, A. Ancy Judi ¹

Affiliations
1 School of Bio and Chemical Engineering, Department of Biomedical Engineering, Sathyabama University, Chennai 600 119, Tamilnadu, IN

Abstract

Nanotechnology is a fast growing and emerging new technology in recent years due to their extensive application. In current scenario, chemically induced synthesis of silver nanoparticles has played a significant role. In this study silver nanoparticles were produced in de-ionized water and dimethyl sulphoxide (DMSO) using D-galactose as reducing agent at 80°C. Silver nitrate (AgNO₃) was employed as the metal precursor for the synthesis of silver nanoparticles (Ag-NPs). D-galactose acted as reducing agent for the conversion of silver salts into silver ions under experimental condition. The formation of nanoparticles and Plasmon resonance kinetic energy was determined by UV - visible spectroscopy. The de-ionized water solution of D-galactose was better reductive activity in 400nm whereas DMSO solution of D-galactose in 350nm. The produced nanoparticles were subjected to perform antimicrobial efficacy against selected pathogens. D-galactose induced silver nanoparticles produced in de-ionized water exhibited higher antimicrobial activity against bacterial pathogens. Among the pathogens tested Pseudomonas aeruginosa and Salmonella paratyphi A showed maximum antibacterial activity. No activity was observed towards yeast Candida albicans. In conclusion D-galactose mediated silver nanoparticles using de-ionized water could be cost effective and eco-friendly technique for bulk production. The characterization studies are under progress to understand the size, shape and topography of the nanoparticles. Further biocompatibility and cytotoxicity studies are essential for pharmaceutical and biomedical applications.

Keywords

Silver Nanoparticles, D-Galactose, DMSO, Antimicrobial Activity, Human Pathogens.

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K. S. Sreekala ¹, S. Krishnakumar ¹

Affiliations
1 Department of Electronics, School of Technology and Applied Sciences, Mahatma Gandhi University, Edappally, Kochi – 682024, Kerala, IN

Abstract

Objectives: This work aims to analyze the the dependency of VDD, T and CR (Cell Ratio) on cell stability in terms of Read Noise Margin (RNM) in 32nm technology by the N- curve and butterfly graphical methods. The advantages of considering both voltage and current information for SRAM cell stability measurement have been reported. Methods/Statistical Analysis: The cell stability calculation of SRAM is a central concern in submicron CMOS process nodes, as they reason for increase in dies variability and voltage scaling. The cell Stability of the SRAM is typically calculated by Static Noise Margin (SNM). As it varies with different operating modes of a cell, a detailed analysis is required. In this article, the RNM of SRAM cell is computed by N curve, which compares with the SNM by bufferfly method. SRAM with PMOS access transistor for improved read stability and low voltage application is also presented. Findings: Results show that proposed SRAM gives 50% cell stability in read mode of operation over conventional SRAM cell for CR=3. Application/Improvements: The typical SRAM bit cell with PMOS access transistor shows improved read stability at low voltage application than standard SRAM cell.

Keywords

Butterfly Curve, Cell Ratio, N-Curve, Pull-Up Ratio, Read stability, RNM, SNM, SRAM, Write Stability

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M. Anandaraj ¹, P. Parameswaran ², S. Krishnakumar ¹, T. Ezhilarasi ², V. Thomas Paul ², R. Thirumurugesan ², S. Chandramouli ¹, V. Ramakrishnan ¹, G. Padmakumar ¹, Shaju K. Albert ², B. K. Nashine ¹, V. Prakash ¹, P. Selvaraj ¹

Affiliations
1 Fast Reactor Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, India - 603 102, IN
2 Metallurgy & Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, India - 603 102, IN

Abstract

One of the spark plug leak detectors employed in high temperature liquid sodium systems had failed to detect a sodium leak and systematic failure analysis was carried out to identify the ischolar_main cause of the failure. Radiography image of the leak port nozzle revealed that the extension wire which was welded with spark plug electrode had snapped. Since the failure originated from the cracks present in the weld, it was decided to standardize the welding procedure of spark plug electrode to extension wire to prevent the possibility of similar failures in future. Three different materials viz, stainless steel, nickel, inconel were chosen as extension wires as well as filler wires to optimize the welding parameters. Microstructural studies in terms of presence of defects, interface integrity between the weld and extension wire as well as that of spark plug electrode were carried out. Based on this, the final choice of welding parameters, material for extension wire and for filler wire to achieve a sound weld was proposed.

Keywords

Spark Plug Detector, Extension Wire, Failure Analysis, Metallography, Welding Procedure Qualification.

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