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Sharma S.K.,Shivalik Institute of Engineering and Technology | Sharma B.S.,Institute of Basic science | Kumar R.,Institute of Basic science | Kumar R.,Rawal Institute of Engineering and Technology
Indian Journal of Pure and Applied Physics | Year: 2013

An expression for the volume dependence of thermal pressure is formulated using basic thermodynamic identities. It is applied to aluminium metal for which sufficiently reliable data are available for comparison. The calculations are performed using the two models viz. the Thomas-Fermi model and the Stacey-Davis model. It is found that the values of thermal pressure for m=6 in both models are almost the same. Thermal pressure increases with the increase in pressure. The anhormonic effects are found to be dominant below about (P=60 GPa). While above this, harmonic effects become dominant. The anharmonic effects are very important at low pressures and become less significant as the pressure is increased. Values of thermal pressure have been calculated by taking into account the effect of the change in volume on melting. The results obtained for aluminium indicate that the present model is capable of predicting the volume dependence of thermal pressure, which is found to be in good agreement with the available data for a wide range of pressures and temperatures.


Pal I.,Guru Jambheshwar University of Science and Technology | Agarwal A.,Guru Jambheshwar University of Science and Technology | Sanghi S.,Guru Jambheshwar University of Science and Technology | Bhardwaj S.,D. C. R. University of Science and Technology | Sanjay S.,Rawal Institute of Engineering and Technology
AIP Conference Proceedings | Year: 2014

In this work, Judd-Ofelt analysis is applied to rare-earth (RE = Nd3+) doped cadmium bismuth silicate (20CdO xSiO2 (79.5-x)Bi2O3 0.5Nd2O3 (CSBN)) glasses in order to evaluate their potential as well as both glass laser systems and optical materials. The phenomenological Judd-Ofelt parameters (Ω2, Ω4, Ω6) are determined for RE ions with their quality factors and compared with the equivalent parameters for several other hosts. The calculated value of stimulated emission cross-section for 4F3/2→4I11/2 has high and varies 14.72×10 -20 to 9.66×10-20 cm2 with Bi2O3 content in the host glass. The results point out that the glass system is good candidate for the development of photonics devices which are operating near infrared spectral range. Further, the FTIR results reveal that the glasses have BiO6, SiO4 and non-bridging oxygen as local structure. © 2014 AIP Publishing LLC.


Gupta V.,Uttarakhand Technical University | Sharma M.,Rawal Institute of Engineering and Technology
OMICS A Journal of Integrative Biology | Year: 2012

Reactive oxygen species (ROS) is a metabolic side product of oxidative stress process, which causes several diseases like atherosclerosis, cancer, etc. In defense of ROS, antioxidants play a key role in combating them. As the process of aging increases, the level of antioxidants in our body decreases and thereby needs utmost attention for its repair process, which is generally administered externally. Plant products serve a best source for controlling these activities by its own metabolic pathway. Studies on the antioxidant activities of Maytenus emarginata leaf extracts are lacking. Antioxidant activity of the methanol extract of Maytenus emarginata was determined by DPPH free radical nitric oxide scavenging assays, superoxide ion scavenging assays, ABTS, and iron chelating methods. Preliminary phytochemical screening revealed that the extract of Maytenus emarginata leaves possesses phenols, flavonoids, steroids, glycosides, saponins, tannins, and triterpenoids. The extract showed significant activities in all antioxidant assays compared to the standard antioxidant (ascorbic acid) in a dose-dependent manner, and remarkable activities to scavenge ROS may be attributed by the presence of the above active compounds in the leaves. The amount of total phenolics and flavonoid contents were also estimated. The DPPH, ABTS, Nitric oxide, superoxide, and iron chelating IC50 values of the methanolic extracts were 12.44, 24.27, 22.41, 5.85, and 2.74 μg/mL, respectively. The total phenolic content of the methanolic extract was 10.69 mg CA/g, whereas the total flavonoid was 1.56 mg CAE/g. The antioxidant activities were correlated with the total phenolic content. This result suggests that the relatively high antioxidant activity of the methanolic extract compared to standard could be possibly be due to its high phenolic content. © 2012 Mary Ann Liebert, Inc.


Patel G.S.,Rawal Institute of Engineering and Technology | Sharma K.,Thapar University
Journal of Computational and Theoretical Nanoscience | Year: 2013

The paper presents a new technique to improve the performance of DDFS (Direct Digital Frequency Synthesis) on FPGA Nanotechnology. It is a kind of frequency synthesizer that uses electronic methods for digitally creating arbitrary waveforms and frequencies from a single, fixed source frequency. DDFS is a mixed signal part i.e., it has both digital and analog parts. DDFS's digital part is also known as Numerically Controlled Oscillator (NCO), which consists of a Phase Register, a Phase Accumulator (PA) and a ROM. The analog part has Digital-to-Analog Converter and a filter. NCO is a digital computing block which renders digital word sequences in time at a given reference clock frequency fclk, which thereafter are converted into analog signals to serve as a synthesizer. The DDFS circuits proposed in this paper compare favorably with previously proposed approaches. The focus of this work is on design, analysis and simulation of DDFS, using tools Xilinx and MATLAB and implement on FPGA Nanotechnology. Copyright © 2013 American Scientific Publishers.


Sanjay,Rawal Institute of Engineering and Technology | Kishore N.,Guru Jambheshwar University of Science and Technology | Agarwal A.,Guru Jambheshwar University of Science and Technology | Dahiya S.,Maharshi Dayanand University | And 2 more authors.
Modern Physics Letters B | Year: 2013

The glasses of compositions xFe2O3 · (40 - x)Bi2O3 · 60B2O3 · 2V2O5 have been prepared by the standard melt-quenching technique. Amorphous nature of these samples is ascertained by XRD patterns. The presence of BO3 and BO4 units is identified by IR spectra of glass samples. The absorption edge (λcut-off) shifts toward longer wavelengths with an increase in Fe2O3 content in the glass matrix. The values of optical band gap energy for indirect allowed and forbidden transitions have been determined and it is found to decrease with increase in transition metal ions. The Urbach's energy is used to characterize the degree of disorder in amorphous solids. © 2013 World Scientific Publishing Company.


Patel G.S.,Rawal Institute of Engineering and Technology | Sharma S.,Thapar University
International Journal of Wavelets, Multiresolution and Information Processing | Year: 2014

Phase Lock Loop (PLL) and Delay Locked Loops (DLLs) are major analog circuits used for many different communication applications such as frequency synthesizer, radio, computer, clock generation and recovery, global positioning system etc. This paper developed a methodical approach to calculate jitter of the PLL and DLL. The methodological nature of our approach would manifest itself in the development of a clear step-by-step procedure for the design of the constituent components of the same. Finally, jitter of DLL has been reduced by proposed technique. © 2014 World Scientific Publishing Company.


Patel G.S.,Rawal Institute of Engineering and Technology | Sharma S.,Thapar University
Journal of Computational and Theoretical Nanoscience | Year: 2014

The paper presents a new technique to improve the performance of All-Digital Phase Locked Loop (ADPLL) IP core on FPGA Nanotechnology. The FPGA maintains the advantages of custom functionality like an ASIC while avoiding the high development costs and the inability to make design modifications after production. If excellent platforms like FPGA have the support of predefined and pre-verified IP cores, the concept of 24 hour system on chip is very much possible. The current design of ADPLL IP core is meant for this very purpose. Implementation of a digital PLL on a FPGA helps to control the jitter involved in the operation of PLLs to a greater extent that is troubling the current communication industry. The proposed work in this paper compare favorably with previously proposed approaches. The focus of this work is on design, analysis and implementation of ADPLL on Xilinx FPGA-Nanotechnology platform. Copyright © 2014 American Scientific Publishers All rights reserved.


Patel G.S.,Rawal Institute of Engineering and Technology | Sharma S.,Thapar University
Wireless Personal Communications | Year: 2014

The work proposed parametric analysis of a novel architecture of phase locked loop (PLL) for pure signal synthesisIt has been widely used in wireless communication systems due to the high frequency resolution and the short locking timeFirst, we presented a mathematical and accurate model of noise in PLL with take into account noise of its componentThen we predicted output phase noise in term of its parametersFinally, we described as effective technique for noise in fractional PLL by CppSim simulatorThe output phase noise has been reduced from-154 to-159 dBc/MHz at 20 MHz offsetThe proposed behavioral simulation results show improvement around 5 dBc/MHzIn future, this technique can also be implemented in hybrid PLL. © 2013 Springer Science+Business Media New York.


Patel G.S.,Rawal Institute of Engineering and Technology | Sharma S.,Thapar University
Wireless Personal Communications | Year: 2014

The aim of this paper is analysis and presenting a technique to reduce phase noise of frequency synthesizer for pure signal synthesis. To reduce phase noise of synthesizer, first, we present a mathematical and accurate model of phase noise in phase locked loop based frequency synthesizer with take into account noise of its component. Then we predict output phase noise in term of its parameters. Finally, we describe as effective technique for phase noise in frequency synthesizer. The simulation results show the performance of the frequency synthesizer for the High Speed communication system. © Springer Science+Business Media New York 2013.


Shukla A.,Rawal Institute of Engineering and Technology | Kaushik V.K.,Shri Gs Institute Of Technology And Science | Prasher D.,Rawal Institute of Engineering and Technology
Electronic Materials Letters | Year: 2014

The growth and characterization of MgxZn1-xO thin films by aerosol-assisted chemical vapor deposition (AACVD) technique is reported in this paper. We have grown the thin films of ZnO by adding varying concentrations of magnesium (Mg) on a glass substrate. The precursor from which the MgxZn1-xO thin films were grown was made up of a mixture of zinc acethylacetonate and magnesium acetate tetrahydrate in boiled isopropyl alcohol. Oxygen gas was used as a carrier gas and substrate temperature was maintained at 400°C. MgxZn1-xO thin films were finally characterized by x-ray diffraction (XRD), atomic force microscopy (AFM) and UV-VIS-NIR spectroscopy. XRD results show that MgxZn1-xO thin films displayed a wurtzite structure and addition of Mg leads to a slight shift towards higher 2-theta values. AFM results show that MgZnO thin films were uniformly covered with nano flakes and their size decreases with an increase in Mg content. Optical studies show that with the increase of Mg content, transparency as well energy band gap of the MgxZn1-xO thin films increases, which also agrees with the reported values. © 2014 The Korean Institute of Metals and Materials and Springer Science+Business Media Dordrecht.

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