Informatics Publishing Limited

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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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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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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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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