Time filter

Source Type

Inamdar K.,Sardar Vallabhbhai National Institute of Technology, Surat | Kosta Y.P.,Marwadi Education Foundation Group of Institutions | Patnaik S.,Xavier Institute of Engineering
Radioelectronics and Communications Systems | Year: 2015

Metamaterials have been an attractive topic for research in the field of electromagnetics in recent years. In this paper, a criss-cross structure has been suggested; this shape has been inspired from the famous Jerusalem Cross. The software analysis of the proposed unit cell structure has been validated experimentally thus giving negative response of ɛ and μ. Following this, a microstrip patch antenna based on suggested metamaterial has been designed. The theory and design formulas to calculate various parameters of the proposed antenna have been presented. The design of a metamaterial based microstrip patch antenna has been optimized for providing of an improved gain, bandwidth and multiple frequency operations. All the antenna performance parameters are compared and presented in table and response-graphs. Also it has been observed that the physical dimensions of the metamaterial based patch antenna are smaller compared to its conventional counterpart operating in the same frequency band. The response of the patch antenna has been verified experimentally either. The important part of the research was to develop metamaterial based on some signature structures and techniques that would offer advantage in terms of bandwidth and multiple frequency operation, that is demonstrated in the paper. The unique shape suggested in this paper provides an improvement in bandwidth without reducing the gain of the antenna. © 2015, Allerton Press, Inc.


PubMed | Indian School of Mines and Marwadi Education Foundation & Group of Institutions
Type: | Journal: Journal of environmental sciences (China) | Year: 2016

Source apportionment study of PM


Joshi J.,Marwadi Education Foundation Group of Institutions | Tekwani P.N.,Nirma University | Shah M.C.,Marwadi Education Foundation Group of Institutions | Sonar P.,Hitachi Ltd.
2014 IEEE International Conference on Power Electronics, Drives and Energy Systems, PEDES 2014 | Year: 2014

Railway wayside signaling is a system used to control railway traffic safely, essentially to prevent trains from colliding. Therefore it is required to have a reliable power supply to keep a healthy and sustainable rail network. The methodology to develop the power supply presented in this paper involves study and implementation of power factor correction (PFC) boost-converter integrated with two-switch DC-DC forward-converter for high voltage and high frequency application using individual digital signal processors (DSPs). The proposed method confirms the efficient and reliable operation of the integrated converters with the line side power factor maintained to near unity for various load conditions. Total Harmonic Distortion (THD) in the input current is also considerably reduced in the proposed scheme. This approach not only reduces the size of magnetic components, but also makes it possible to achieve a fully-controlled AC-DC-AC converter when further integrated with single-phase inverter. © 2014 IEEE.


Patel S.K.,Sudan University of Science and Technology | Kosta Y.P.,Marwadi Education Foundation Group of Institutions
Journal of Modern Optics | Year: 2014

We have introduced metamaterial superstrate in microstrip-based radiating structure to increase its bandwidth. Split ring resonators are added as metamaterial metallic inclusion in superstrate of the conventional design. This changes the basic structure of the material. Material properties such as permittivity and permeability changed due to change in the structure. The change in its material properties enhances the bandwidth of the antenna. The antenna is meandered to achieve better performance at the edges which in a way improve the radiation path of the patch. Here, the proposed antenna works on three bands in the range 3-8 GHz. Maximum 60% bandwidth is enhanced in the third band. The voltage standing wave ratio and return loss (S11) of the entire three bands are shown in the paper. The antenna works on 3.51, 4.86 and 7.8 GHz. Design results are obtained by high-frequency structure simulator which is used for simulating microwave passive components. © 2014 Taylor & Francis.


Patel S.K.,University of Nebraska - Lincoln | Argyropoulos C.,University of Nebraska - Lincoln | Kosta Y.P.,Marwadi Education Foundation Group of Institutions
Waves in Random and Complex Media | Year: 2016

We present microstrip patch antenna loaded with multiple split ring resonator substrate and superstrate. We analyze how the loading of split ring resonator superstrate and substrate can improve the bandwidth compared to the simple microstrip patch antenna and microstrip patch antenna loaded with split ring resonator superstrate. Another important observation is made for multiple split ring resonator loading in superstrate and substrate of microstrip patch antenna. The design is compared for two, three, and four-ring split ring resonator loading. The designs are also compared for different gap spacing between the rings. All three designs are compared for small gap and large gap between the rings. The design results in the form of reflection coefficient and bandwidth is presented in this manuscript. The design results are also compared with previously published designs. © 2016 Informa UK Limited, trading as Taylor & Francis Group


Gupta S.K.,Indian Institute of Technology Roorkee | Dangar D.,Marwadi Education Foundation Group of Institutions
Fuzzy Optimization and Decision Making | Year: 2014

In this paper, a Mond-Weir type dual program for a nonlinear primal problem under fuzzy environment is formulated. The solution concept of primal-dual problems is inspired by the nondominated solution. We have considered ordering among fuzzy numbers as a partial ordering and using the concept of Hukuhara difference between two fuzzy numbers and H-differentiability, appropriate duality theorems are established under pseudo/quasi-convexity assumptions.We have also illustrated a numerical example which satisfies the duality relations discussed in the paper. © Springer Science+Business Media New York 2013.


Motwani K.H.,Marwadi Education Foundation Group of Institutions | Jain S.V.,Nirma University | Patel R.N.,Nirma University
Procedia Engineering | Year: 2013

The energy scenario in rural, remote and hilly areas of India is characterized by inadequate, poor and unreliable supply of energy services. In such regions, the load density is low and extension of grid system is totally uneconomical, hence the small hydropower schemes can provide a solution for the energy problems besides solar photovoltaic, which is not available throughout the day. The main hindrance in implementing such hydropower schemes is high initial cost of conventional hydro turbines. The cost of these plants can be brought down by using centrifugal pump in turbine mode in context of various advantages associated with the pumps viz. low initial and maintenance cost, ready availability, simple construction etc. However, the efficiency of pump as turbine (PAT) is lower than that of conventional hydro turbines. For commercial justification of PAT technology, a cost analysis of 3 kW capacity pico hydropower plant was carried out by considering PAT and Francis turbine as a prime mover. The hydro turbine test rig was developed by installing PAT and its performance characteristics were plotted. The annual life cycle cost (ALCC) analysis was carried out based on initial cost of the project, capital recovery factor and annual expenses. Based on the analysis, the ALCC and the cost of electricity generated per unit were found to be very less for PAT than that of Francis turbine, which has justified the use of PAT for the case under consideration. © 2012 Published by Elsevier Ltd.


Kumar A.,Marwadi Education Foundation Group of Institutions | Bhojani P.,Marwadi Education Foundation Group of Institutions
2nd International Conference on Electronics and Communication Systems, ICECS 2015 | Year: 2015

The reliability issues like Negative Bias Temperature Instability and Hot Carrier Injection are major concerns in nanoscale design of MOSFET applications. This necessitates that model with higher accuracy for prediction of these degradations and to calculate the lifetime of the CMOS application circuits. Earlier models available in literature are reported to be accurate but the huge time is consumed in evaluating these effects. Hence, we were motivated to propose extended & new models, which evaluate much faster than the available models. We propose a methodology, which uses these models and simulates the circuit degradation due to the effect of NBTI and HCI in CMOS circuit design, and subsequently predicts the lifetime of the circuit. This tool, which we call as Reliability Analysis Tool (ReAl) uses computational support of MATLAB, whereas utilizing accuracy of SPICE simulation for model building, and integrates both in order to provide the lifetime of the CMOS circuit under consideration. © 2015 IEEE.


Patel V.A.,Essar Steel India Ltd | Jain S.V.,Nirma University | Motwani K.H.,Marwadi Education Foundation Group of Institutions | Patel R.N.,Nirma University
Procedia Engineering | Year: 2013

The main limitation of centrifugal pump running in turbine mode is lower efficiency at part load operating conditions as compared to conventional hydro turbines. To enhance the utilization of pump as turbine (PAT) in mini/micro hydropower plants, it is very important to improve its performance with some low cost modifications. The part load efficiency of PAT can be improved by guiding the flow at part load by installing the movable guide vanes. However, to avoid the higher cost of movable guide vanes, it was proposed to install fixed guide vanes. The existing volute casing of centrifugal pump was not having sufficient space for provision of guide vane mechanism. Hence, to create an additional space the existing impeller of 250 mm dia. was replaced by 200 mm dia. impeller which has facilitated an additional space for installation of guide vanes. To determine the optimum position of fixed guide vanes, CFD analysis of casing was carried out with NACA-4418 profile by varying the guide vane angles between 45° to 80°. The numerical simulations were carried out using Reynolds averaged Navier-Stokes (RANS) equations with standard k-ε turbulence model under steady state conditions. In addition, it was required to place the reducer between the service pump and PAT as the pipe dia. at service pump outlet was 5" and at PAT inlet was 3". To optimize the shape and location of reducer between service pump and PAT, CFD analysis was performed by considering two different reducers at different locations. PAT with 200 mm dia. impeller and 8 numbers of fixed guide vanes provided at 75° angle led to improved performance of PAT. Also the long reducer provided at the inlet of PAT was subjected to less head drop in the piping system. © 2012 Published by Elsevier Ltd.


Chaudhuri A.,Marwadi Education Foundation Group of Institutions
International Journal of Agricultural and Environmental Information Systems | Year: 2013

Forecasting rice production is a challenging problem in agricultural statistics. The inherent difficulty lies in demand and supply affected by many uncertain factors viz. economic policies, agricultural factors, credit measures, foreign trade etc. which interact in a complex manner. Since last few decades, Statistical techniques are used for developing predictive models to estimate required parameters. Determination of nature of rice production time series data is difficult, expensive, time consuming and involves tedious tests. In this paper, we use Interval Type n Fuzzy Auto Regressive Integrated Moving Average (ITnARIMA), Adaptive Neuro Fuzzy Inference System (ANFIS) and Modified Regularized Least Squares Fuzzy Support Vector Regression (MRLSFSVR) for prediction of Productivity Index percent (PI %) of rice production time series data and compare it with traditional Statistical tool of Multiple Regression. The accuracies of ITnARIMA and ANFIS techniques are evaluated as relatively similar. It is found that ANFIS exhibits high performance than ITnARIMA, MRLSFSVR and Multiple Regression for predicting PI %. The performance comparison shows that Computational Intelligence paradigm is a promising tool for minimizing uncertainties in rice production data. Further Computational Intelligence techniques also minimize potential inconsistency of correlations. Copyright © 2013, IGI Global.

Loading Marwadi Education Foundation Group of Institutions collaborators
Loading Marwadi Education Foundation Group of Institutions collaborators