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Your search keyword '"Kumar, A.V."' showing total 118 results
Start Over Author "Kumar, A.V." Publication Type Academic Journals
118 results on '"Kumar, A.V."'

9. Development of light weight transparent bullet proof polymeric laminates

Author

Kumar, A.V. Anil, Pothuraju, Kollipaka, Lakshmi, K. Rajya, and Bhowmik, Shantanu

Subjects
PVH Corp., Clothing industry -- Analysis -- Usage, Bombs -- Usage, Laminated materials -- Usage, Improvised explosive devices -- Analysis -- Usage, Polycarbonates -- Usage, Engineering and manufacturing industries, Science and technology
Abstract

Armed vehicles, improvised explosive device blast-proof vehicles, require their windshields and windows to be transparent and yet be resistant to high-velocity impact of splinters. Hence, composite which is of ballistic grade and yet transparent is in real need for all these applications. This study is dedicated to finding a practical solution for using transparent polycarbonate (PC) laminate made using solvent vapor bonding for ballistic applications. The solvent that was proved to be best for solvent vapor bonding of polycarbonate sheets was dichloromethane, as the bond strength was observed to be high from the results of lap shear tensile test. The transparency retention is reasonably high when solvent vapor bonding was used and the toughness has increased near to 50% in comparison with nonlaminated PC. In this study, a polycarbonate laminate with dimensions 150 * 150 * 40 mm made using solvent vapor bonding and is tested with two 9-mm bullets fired with velocity of 430 m/s from a distance of 5 m. The laminae successfully stopped both the bullets without any back face signature and there was no brittle failure as such, rather delamination happened at interface of laminae since it has essentially absorbed the impact energy of bullet. Highlights * Solvent vapor bonding of polycarbonate laminate. * Transparent ballistic shield with layer of polycarbonate laminate. * Enhancement of mechanical properties of solvent-vaporized bonding polycarbonate laminate. * Ballistic testing of transparent polycarbonate laminate. KEYWORDS composites, impact resistance, polycarbonates, toughness, transparency, 1 | INTRODUCTION Police officers, military personnel, and members of the armed forces are often under threat. They are exposed to the risks, varying from rock pelting to gun fires. [...]

Published
2023
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46. Diffusion of propane in zeolite NaY: A molecular dynamics and quasi-elastic neutron scattering study

Author

Sayeed, Ahmed, Chaplot, S.L., Mitra, S., Anil Kumar, A.V., Mukhopadhyay, R., and Yashonath, S.

Subjects
Molecular dynamics -- Research, Propane -- Chemical properties, Propane -- Research, Diffusion -- Analysis, Chemicals, plastics and rubber industries
Abstract

Results obtained from molecular dynamics (MD) simulations and quasi-elastic neutron scattering (QENS) measurements of diffusion of propane in NaY zeolite are reported. The results obtained are in good agreement with the experimental QENS results.

Published
2003

47. Simulated experimental investigation of microplastic weathering in marine environment.

Author

Yadav, Sonali, Rout, Sabyasachi, Tiwari, Mahesh, Mhatre, Sachin, Karpe, Rupali, Pulhani, Vandana, and Kumar, A.V.

Subjects
PLASTIC marine debris, COLONIZATION (Ecology), BACKGROUND radiation, SURFACE cracks, MICROPLASTICS, RADIATION exposure
Abstract

Microplastics act as a potential vector for a wide range of contaminants, which have emerged as a major environmental hazard in the modern world. Considering the seriousness of the problem, a simulated laboratory and field experiment were conducted to study the weathering of pristine microplastics following long-term exposure to natural background radiation and the marine environment after being disposed of in the open environment. For the study, polyethylene-originating (HDPE and LDPE) microplastics were chosen. The study revealed that radiation exposure causes surface roughness and cracks, leading to an increased surface area, which can invite a wide spectrum of pollutants to sorb on their surface. Furthermore, we report that the radiation-induced morphological changes favor microbial colonization on the microplastic surface when exposed to the marine environment. The growth of biofilms on the surface of microplastics reduces their hydrophobicity, which may attract a wide variety of polar contaminants. The study led to an interesting finding: that the HDPE microplastic surface is more conducive for biofilm growth in comparison to the LDPE surface. [ABSTRACT FROM AUTHOR]

Published
2022
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50. Generation of microwave free-electron laser radiation using sheet electron beam and planar electromagnet wiggler

Author

Kumar, A.V. Ravi, Mohandas, K.K., and Jain, K.K.

Subjects
Microwaves -- Research, Free electron lasers -- Research, Electron beams -- Research, Electromagnets -- Usage, Business, Chemistry, Electronics, Electronics and electrical industries
Abstract

An experimental study of sheet electron beam propagation through a planar electromagnet wiggler and generation of microwave radiation by free-electron laser action has been carried out. The space charge dominated sheet electron beam of energy [approximately]100-200 keV, current 50-150 A, and pulsewidth of 100-150 ns was propagated through a 20-period planar electromagnetic wiggler. Significant enhancement in the beam transmission through the wiggler was observed as the wiggler magnetic field was increased, even though the operating regime of the beam is space charge dominated. Generation of microwave radiation in E-band (60-90 GHz) was also observed when the sheet electron beam is injected through the wiggler in the presence of wiggler magnetic field. Index Terms - Free-electron laser, microwave generation, planar electromagnet wiggler, sheet electron beam propagation.

Published
1998

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