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Sahu O.P.,National Institute of Technology Kurukshetra | Kumar S.,Terminal Ballistics Research Laboratory
IETE Journal of Research | Year: 2011

The rapidly increasing need for information communication requires higher speed data transmission over the existing channels. The data rate over these channels is limited mainly by Inter Symbol Interference (ISI). Channel equalizers are used to reduce the effect of ISI. In this paper, a new equalizer based on adaptive neuro-fuzzy inference system is presented. The performance of the proposed equalizer is evaluated for both linear as well as non-linear channels in terms of bit-error rate for different noise powers. Simulation results show that the proposed equalizer has better Bit Error Rate (BER) performance compared to multi-layer perceptron and least mean square equalizers. However, its BER performance is slightly poorer than that of radial basis function network and optimal Bayesian equalizer but is better in terms of structural complexity. Source

Kumar R.,Indian Institute of Technology Mandi | Siril P.F.,Indian Institute of Technology Mandi | Soni P.,Terminal Ballistics Research Laboratory
Propellants, Explosives, Pyrotechnics | Year: 2014

Nanoparticles of cyclotrimethylenetrinitramine (RDX) were prepared by a simple re-precipitation method using acetone as solvent and water as the antisolvent. The effect of changing experimental parameters such as ratio of solvent to antisolvent, temperature of antisolvent during injection and concentration of solution on particle size and morphology of RDX was systematically studied. The size of the particles was characterized using dynamic light scattering (DLS) and field emission scanning electron microscopy (FESEM). The mean particle size of the RDX nanoparticles according to FESEM analysis ranged from 40 nm to 230 nm under different conditions of preparation. The UV/Vis absorption maximum of nano-RDX was found to be blue shifted when compared to the absorption maximum for bulk-RDX. Powder X-ray diffraction (XRD) results showed that RDX nanoparticles precipitated in stable α-crystalline form. Fourier transform infrared (FTIR) spectroscopy was used to characterize the chemical nature of the nano-RDX. Thermal characterization of the RDX-nanoparticles was done using simultaneous thermogravimetric analysis coupled with differential scanning calorimetry (TGA-DSC). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Khosla P.K.,Terminal Ballistics Research Laboratory | Khanna R.,Thapar University | Sood S.P.,Center for Development of Advanced Computing of India
Defence Science Journal | Year: 2014

The rail track rocket sled (RTRS) national test facility at Terminal Ballistics Research Laboratory (TBRL) has been established to provide simulated flight environment for carrying out aero dynamic studies, terminal studies and kinematic studies of variety of test articles. The sled velocity is a critical parameter in evaluation trials. This velocity is also used to ensure that the maximum speed and allowable g loading does not exceed the value which the test article will experience under free flight in air1. Overseas, the facilities have been set up to attain velocities ranging from sub-sonic to hypersonic2. The rocket sled at TBRL can be presently accelerated to travel along the rail track at velocities up to 500 m/s and capability is being built to increase velocity beyond 500 m/s. Signals acquired from existing magneto-inductive arrangement have been analysed in the present work. The experiments indicate that with increase in velocity the rate of change of flux increases, the amplitude of induced emf also increases but terminal voltage decreases and shape of the acquired pulse gets distorted. The parameters of magneto-inductive pick up have been modified in such a way that there is improvement in amplitude and shape of the received pulse with increase in velocity. The improved signals have been analysed and simulation results validated with feasible experiments. This paper also discusses issues, challenges and proposes recommendations in improving the sensor for measurement of velocity beyond Mach 1.5. It has been found that it is prudent to reduce the inductance by reducing the number of turns and changing the core from soft iron core to air core which will improve the response of inductive pick up coil at high velocity. © 2014, DESIDOC. Source

Sharma A.D.,Himachal Pradesh University | Sharma A.K.,Terminal Ballistics Research Laboratory | Thakur N.,Himachal Pradesh University
Philosophical Magazine | Year: 2012

Micro-sized copper powder has been compacted using explosives of various detonation velocities. Corresponding crystallographic and morphological characteristics along with particle size variation have also been compared. Cylindrical configuration has been used for the shock consolidation of metal powder. It has been observed that using an explosive mixture of detonation velocity 4.2km/s, the crystallite and micro-structure of the compacts remains the same with intact dendritic structure accompanied by a small variation in particle sizes. A good order of micro-hardness (88±4) H v and density of ∼94% of the theoretical value has been observed with lesser melting compared to the compacts obtained using explosive mixture with a high detonation velocity. © 2012 Copyright Taylor and Francis Group, LLC. Source

Sharma A.K.,Terminal Ballistics Research Laboratory
Proceedings - 27th International Symposium on Ballistics, BALLISTICS 2013 | Year: 2013

A well defined experimental programme coupled with computer simulation studies has been planned to design hemi spherical charge for defeat of hardened earth. The work reported in this paper is confined to theoretical and experimental aspects peripheral to the elements of hollow charge penetration in to earth. Before actual experimentation, hollow charge penetration analysis has been carried out by using a computer code. The emphasis on technology development and adaptation is towards hemi spherical charge penetration in to the earth and subsequent cratering to heave the shattered earth in to air for minimum ejecta fall back in to crater. Source

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