Haque S.M.,Bhabha Atomic Research Center |
Sagdeo P.R.,Indian Institute of Technology Indore |
Sagdeo A.,INDUS Technology |
Jha S.N.,Bhabha Atomic Research Center |
And 2 more authors.
Applied Optics | Year: 2015
A set of titanium dioxide thin films have been deposited on fused silica substrates by the novel asymmetric bipolar pulsed dc reactive sputtering technique using different oxygen partial pressures in the sputtering ambient in the range of 0%-21%. For investigating long-range structural properties of the samples, grazing incidence x-ray diffraction (GIXRD) measurements and for probing local structure surrounding Ti sites, extended x-ray absorption fine structure (EXAFS) measurements have been carried out. Optical properties of the films have been investigated by transmission spectrophotometry in UV-visible-near IR range and it has been observed that as oxygen partial pressure in the sputtering ambient is increased, refractive index of the films varies in a nonlinear fashion. Microscopically, it has been found that this nonlinear variation can be explained by the local structure tool EXAFS, while GIXRD which works on average long-range order fails to explain this. Such a variation of optical properties with increase in oxygen partial pressure during deposition of the films is attributed to the competition between the two processes, viz., improvement in the stoichiometry of the films and reduction in the mobility of the adatoms on the surface of the growing films. © 2015 Optical Society of America.
Pradhan G.K.,Jawaharlal Nehru Centre for Advanced Scientific Research |
Kumar A.,Jawaharlal Nehru Centre for Advanced Scientific Research |
Deb S.K.,INDUS Technology |
Waghmare U.V.,Jawaharlal Nehru Centre for Advanced Scientific Research |
Narayana C.,Jawaharlal Nehru Centre for Advanced Scientific Research
Physical Review B - Condensed Matter and Materials Physics | Year: 2010
We use in situ high-pressure angle dispersive x-ray diffraction measurements to determine the equation of state of cubic tin nitride (γ -Sn3 N4) under pressure up to 26 GPa. While we find no evidence for any structural phase transition, our estimate of the bulk modulus (B0) is 149 (±1.2) GPa, much lower than the earlier theoretical estimates and that of other group IV-nitrides. We corroborate and understand these results with complementary first-principles analysis of structural, elastic, and vibrational properties of group IV-nitrides, and predict a structural transition of Sn3 N4 at a higher pressure of 88 GPa compared to earlier predictions of 40 GPa. Our comparative analysis of cubic nitrides shows that bulk modulus of cubic C3 N 4 is the highest (379 GPa) while it is structurally unstable and should not exist at ambient conditions. © 2010 The American Physical Society.
Sah R.,INDUS Technology |
Dutta S.K.,M. S. University of Baroda
Mineral Processing and Extractive Metallurgy Review | Year: 2010
Large amounts of fines and superfines are generated in Indian iron ore and coal mines due to mechanized mining and mineral dressing operations. Utilization of these fines for extracting metal is of vital concern for resource utilization and pollution control. For agglomeration of these fines, a suitable binder is required. Iron ore-coal composite pellets were prepared by cold bonding. Various binders such as lime, Ca(OH)2, slaked lime, dextrose, molasses, and sodium polyacrylate (SPA), alone or in combination, were employed for making composite briquettes. The slaked lime-dextrose combination produced the highest strength among the various binders employed for producing composite briquettes and was therefore selected for producing composite pellets for the smelting reduction. In cold bonding, the composite pellets attain the requisite properties due to physico-chemical changes of the binder in ambient conditions. It was possible to obtain a dry strength of more than 300N per pellet in some cases and more than 200N per pellet in many trials. Drop strength and shatter index values of composite pellets were also measured. In the present paper an attempt has been made to evaluate the mechanical properties of cold-bonded composite pellets so as to throw some light on the capacity of these pellets to withstand stresses during handling and transportation. © 2010 Taylor & Francis Group, LLC.
Jha B.K.,Gujarat University |
Jha A.,INDUS Technology
Procedia Computer Science | Year: 2015
Astrocytes releases glio-transmitters in a Ca2+-dependent manner. The endoplasmic reticulum, major Ca2+ storage organelle in astrocytes, contains high calcium concentration level than the cytosol. The release of calcium ions from the ER is a central process that affects the cytosolic calcium concentration label in astrocytes. A mathematical model is developed in the form of two dimensional diffusion equation to study the calcium exchanges one across the ER in Astrocytes. All important parameters like diffusion coefficient and influx over [Ca2+] profile, ER fluxes like, Jleak JPump and JChan has been studied. Finite volume method (FVM) is employed to solve the problem and simulated in MATLAB to compute the numerical results. © 2015 The Authors.
Jha A.,INDUS Technology |
Jha B.K.,Gujarat University
Procedia Computer Science | Year: 2015
Many cells use diffusion in calcium concentration transmits messages in the form of chemical signaling. The diffusion of calcium provided numerous results influx of calcium in the cytosol and bind with buffer by pump. In this paper, the model incorporates the physiological parameters like diffusion coefficient, excess buffer etc. Appropriate boundary conditions have been framed. Finite element model using two-dimensional triangular ring elements has been developed to study radial and angular calcium diffusion problem in neuron. Computer simulation in MATLAB 7.11 are employed to investigate mathematical models of reaction diffusion equation, the details of the implementation can heavily affect the numerical solutions and, thus, the outcome simulated on Core(TM) i3 CPU M 330 2.13 GHz processing speed and 3 GB memory. © 2015 The Authors. Published by Elsevier B.V.
Chen Q.,INDUS Technology |
Shao F.,INDUS Technology |
Wu G.,INDUS Technology
Advanced Materials Research | Year: 2012
The sulfonated poly(ether ether ketone) (SPEEK)/bisphenol S diglycidyl ether (DEBS)/POSS ternary hybrids is designed and prepared to incorporate POSS into SPEEK to form a new cross-linked proton exchange membrane (PEM). Compared with the SPEEK, the ternary hybrids possesses lower water uptake (WU) and linear expansion (LE), but higher proton conductivity. The proton conductivity of SPEEK/DEBS/POSS can reach to 1.1×10 -1S/cm. © (2012) Trans Tech Publications, Switzerland.
Mahajan M.,Antenna Systems Group |
Jyoti R.,Antenna Systems Group |
Sood K.,Antenna Systems Group |
Sharma S.B.,INDUS Technology
IEEE Transactions on Antennas and Propagation | Year: 2013
This communication deals with simultaneous generation of a contoured and a pencil beam from a single shaped reflector with two feeds. A novel concept of generating a high gain pencil beam from a shaped reflector is presented using focal plane conjugate field matching method. The contoured beam is generated from the shaped reflector by introducing deformations in a parabolic reflector surface. This communication proposes a simple method to counteract the effects of shaping and generate an additional high gain pencil beam from the shaped reflector. This is achieved by using a single feed which is axially and laterally displaced from the focal point. The proposed method is successfully applied to generate an Indian main land coverage contoured beam and a high gain pencil beam over Andaman Islands. The contoured beam with peak gain of 33.05 dBi and the pencil beam with 43.8 dBi peak gain is generated using the single shaped reflector and two feeds. This technique saves mass and volume otherwise would have required for feed cluster to compensate for the surface distortion. © 2013 IEEE.
INDUS Technology | Date: 2013-01-01
Garg R.,INDUS Technology |
Singh H.,National Institute of Technology Kurukshetra
International Journal of Manufacturing Technology and Management | Year: 2012
Electrical discharge wire cutting, more commonly known as wire electrical discharge machining (WEDM), is a spark erosion process used to produce complex two- and three-dimensional shapes through electrically conductive work pieces by using wire electrode. The practical technology of the WEDM process is based on the conventional EDM sparking phenomenon utilising the widely accepted non-contact technique of material removal. In this paper, the various process parameters of WEDM like pulse on time (TON), pulse off time (TOFF),spark gap set voltage (SV), peak current (IP), wire feed (WF) and wire tension (WT) have been optimised to get their maximum impact on gap current (Ig) so as to obtain maximum material removal rate for hot die steel (H-11) material. Experimental investigation based on Taguchi's L-27 orthogonal array has been done. Signal-to-noise (S/N) ratio, analysis of variance (ANOVA) and various plots are generated to predict the optimal set of process parameters to maximise the gap current. The confirmation experiments have also been conducted to validate the results obtained by Taguchi technique. Copyright © 2012 Inderscience Enterprises Ltd.