Documents published in Scipedia

• Design of microstrip-fed printed UWB diversity antenna with tee crossed shaped structure

  R. Kumar, G. Surushe

  Collection of Engineering Science and Technology, an International Journal (2017).

  
  

  Abstract

  A compact, Ultra Wideband (UWB) antenna system for multi-input multi-output (MIMO)/diversity application is proposed. The antenna system is a microstrip structure with two similar triangular shaped radiating elements and a common ground plane. The radiating elements are excited by tapered feed for better impedance matching. A T-crossed shaped stub is added in the ground plane to increase the isolation between the two radiators. The overall dimension of the proposed antenna system is 46 mm × 32.6 mm × 1.6 mm. The measured impedance bandwidth (reflection coefficient < −10 dB) is from 1.8 GHz to well beyond 12 GHz which covers the entire UWB region. A measured isolation of 15 dB or better is achieved in the UWB region. The diversity gain of the antenna system is close to 10 dBi and the envelope correlation coefficient is well below 0.2 in the operating band. Parametric study is also done to check the sensitivity of the antenna in terms of reflection coefficient and isolation to the different parameters. These characteristics show that the proposed antenna is suitable for the MIMO/diversity application.

  Abstract
  A compact, Ultra Wideband (UWB) antenna system for multi-input multi-output (MIMO)/diversity application is proposed. The antenna system is a microstrip structure with two [...]

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• Analysis of low mutual coupling compact multi-band microstrip patch antenna and its array using defected ground structure

  M. Kumar, V. Nath

  Collection of Engineering Science and Technology, an International Journal (2017).

  
  

  Abstract

  In this paper, a simple microstrip patch antenna and a two-element E-plane coupled microstrip antenna array employing a defected ground structure are investigated. Without defected ground structure, the antenna has an impedance bandwidth of 675 MHz (6.78% at the center frequency of 9.955 GHz) and a gain of around 4.38 dB. The performance of the microstrip antenna in terms of impedance bandwidth, matching performance, gain and return loss can be improved by introducing a defect in the ground plane. As a result of which, bandwidth of 1.652 GHz (16.42% at the center frequency of 10.06 GHz) and a gain of 8.96 dB along with 5 different other operating bands are achieved. After integrating the microstrip antenna with the proposed defected ground structure, effective footprint of the antenna is reduced up to 66.95%. When integrated with proposed DGS array, the same antenna array structure shows miniaturization up to 78.97%. The proposed defected ground structure when compared to other techniques shows an exceptionally lower mutual coupling between two E-plane coupled microstrip antenna elements.

  Abstract
  In this paper, a simple microstrip patch antenna and a two-element E-plane coupled microstrip antenna array employing a defected ground structure are investigated. Without [...]

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• Exploration of waste cooking oil methyl esters (WCOME) as fuel in compression ignition engines: A critical review

  S. Kathirvel, A. Layek, S. Muthuraman

  Collection of Engineering Science and Technology, an International Journal (2017).

  
  

  Abstract

  The ever growing human population and the corresponding economic development of mankind have caused a relentless surge in the energy demand of the world. The fast diminishing fossil fuel reserves and the overdependence of petroleum based fuels have already prompted the world to look for alternate sources of energy to offset the fuel crisis in the future. Waste Cooking Oil Methyl Ester (WCOME) has proven itself as a viable alternate fuel that can be used in Compression Ignition (CI) engines due to its low cost, non-toxicity, biodegradability and renewable nature. It also contributes a minimum amount of net greenhouse gases, such as CO2, SO2 and NO emissions to the atmosphere. The main objective of this paper is to focus on the study of the performance, combustion and emission parameters of CI engines using WCOME and to explore the possibility of utilizing WCOME blends with diesel extensively in place of diesel. The production methods used for transesterification play a vital role in the physiochemical properties of the methyl esters produced. Various production intensification technologies such as hydrodynamic cavitation and ultrasonic cavitation were employed to improve the yield of the methyl esters during transesterification. This review includes the study of WCOME from different origins in various types of diesel engines. Most of the studies comply with the decrease in carbon monoxide (CO) emissions and the increase in brake thermal efficiency while using WCOME in CI engines. Many researchers reported slight increase in the emissions of oxides of nitrogen. ANN modeling has been widely used to predict the process variables of the diesel engine while using WCOME. The versatility of ANN modeling was proven by the minimum error percentages of the actual and predicted values of the performance and emission characteristics.

  Abstract
  The ever growing human population and the corresponding economic development of mankind have caused a relentless surge in the energy demand of the world. The fast diminishing [...]

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• Fast vector quantization using a Bat algorithm for image compression

  C. Karri, U. Jena

  Collection of Engineering Science and Technology, an International Journal (2017).

  
  

  Abstract

  Linde–Buzo–Gray (LBG), a traditional method of vector quantization (VQ) generates a local optimal codebook which results in lower PSNR value. The performance of vector quantization (VQ) depends on the appropriate codebook, so researchers proposed optimization techniques for global codebook generation. Particle swarm optimization (PSO) and Firefly algorithm (FA) generate an efficient codebook, but undergoes instability in convergence when particle velocity is high and non-availability of brighter fireflies in the search space respectively. In this paper, we propose a new algorithm called BA-LBG which uses Bat Algorithm on initial solution of LBG. It produces an efficient codebook with less computational time and results very good PSNR due to its automatic zooming feature using adjustable pulse emission rate and loudness of bats. From the results, we observed that BA-LBG has high PSNR compared to LBG, PSO-LBG, Quantum PSO-LBG, HBMO-LBG and FA-LBG, and its average convergence speed is 1.841 times faster than HBMO-LBG and FA-LBG but no significance difference with PSO.

  Abstract
  Linde–Buzo–Gray (LBG), a traditional method of vector quantization (VQ) generates a local optimal codebook which results in lower PSNR value. The performance of vector [...]

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• Impact of chemical reaction on Cu, Al2 O3 and SWCNTs–nanofluid flow under slip conditions

  R. Kandasamy, R. Mohamad, M. Ismoen

  Collection of Engineering Science and Technology, an International Journal (2017).

  
  

  Abstract

  Single walled carbon nanotube, alumina and copper nanoparticles on convective mass transfer in the presence of base fluid (water) over a horizontal plate are investigated numerically. The governing partial differential equations with auxiliary conditions are reduced into the system of coupled ordinary differential equations via similarity transformation and it has been solved numerically using fourth or fifth order Runge–Kutta–Fehlberg method with shooting technique. The results display that the diffusion boundary layer thickness of the water based Cu and SWCNTs is stronger than Al2 O3 –water with increase of chemical reaction.

  Abstract
  Single walled carbon nanotube, alumina and copper nanoparticles on convective mass transfer in the presence of base fluid (water) over a horizontal plate are investigated [...]

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• Comparison of reliability techniques of parametric and non-parametric method

  C. Kalaiselvan, L. Rao

  Collection of Engineering Science and Technology, an International Journal (2017).

  
  

  Abstract

  Reliability of a product or system is the probability that the product performs adequately its intended function for the stated period of time under stated operating conditions. It is function of time. The most widely used nano ceramic capacitor C0G and X7R is used in this reliability study to generate the Time-to failure (TTF) data. The time to failure data are identified by Accelerated Life Test (ALT) and Highly Accelerated Life Testing (HALT). The test is conducted at high stress level to generate more failure rate within the short interval of time. The reliability method used to convert accelerated to actual condition is Parametric method and Non-Parametric method. In this paper, comparative study has been done for Parametric and Non-Parametric methods to identify the failure data. The Weibull distribution is identified for parametric method, Kaplan–Meier and Simple Actuarial Method are identified for non-parametric method. The time taken to identify the mean time to failure (MTTF) in accelerating condition is the same for parametric and non-parametric method with relative deviation.

  Abstract
  Reliability of a product or system is the probability that the product performs adequately its intended function for the stated period of time under stated operating conditions. [...]

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• Parametric simulation and experimental analysis of earth air heat exchanger with solar air heating duct

  S. Jakhar, R. Misra, M. Soni, N. Gakkhar

  Collection of Engineering Science and Technology, an International Journal (2017).

  
  

  Abstract

  Earth air heat exchanger (EAHE) systems are insufficient to meet the thermal comfort requirements in winter conditions. The low heating potential of such systems can be improved by integrating the system with solar air heating duct (SAHD). The aim of this paper is to present a model to estimate the heating potential for EAHE system with and without SAHD. The model is generated using TRNSYS 17 simulation tool and validated against experimental investigation on an experimental set-up in Ajmer, India. The experiment was done during the winter season, where the system was evaluated for different inlet flow velocities, length and depth of buried pipe. From the experimentation, it was observed that the depth of 3.7 m is sufficient for pipe burial and the 34 m length of pipe is sufficient to get optimum EAHE outlet temperature. It is also observed that increase in flow velocity results in drop in EAHE outlet temperature, while room temperature is found to increase for higher velocities (5 m/s). The COP of the system also increased up to 6.304 when assisted with solar air heating duct. The results obtained from the experiment data are in good agreement with simulated results within the variation of up to 7.9%.

  Abstract
  Earth air heat exchanger (EAHE) systems are insufficient to meet the thermal comfort requirements in winter conditions. The low heating potential of such systems can be improved [...]

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• An improved energy aware distributed unequal clustering protocol for heterogeneous wireless sensor networks

  V. Gupta, R. Pandey

  Collection of Engineering Science and Technology, an International Journal (2017).

  
  

  Abstract

  In this paper, an improved version of the energy aware distributed unequal clustering protocol (EADUC) is projected. The EADUC protocol is commonly used for solving energy hole problem in multi-hop wireless sensor networks. In the EADUC, location of base station and residual energy are given importance as clustering parameters. Based on these parameters, different competition radii are assigned to nodes. Herein, a new approach has been proposed to improve the working of EADUC, by electing cluster heads considering number of nodes in the neighborhood in addition to the above two parameters. The inclusion of the neighborhood information for computation of the competition radii provides better balancing of energy in comparison with the existing approach. Furthermore, for the selection of next hop node, the relay metric is defined directly in terms of energy expense instead of only the distance information used in the EADUC and the data transmission phase has been extended in every round by performing the data collection number of times through use of major slots and mini-slots. The methodology used is of retaining the same clusters for a few rounds and is effective in reducing the clustering overhead. The performance of the proposed protocol has been evaluated under three different scenarios and compared with existing protocols through simulations. The results show that the proposed scheme outperforms the existing protocols in terms of network lifetime in all the scenarios.

  Abstract
  In this paper, an improved version of the energy aware distributed unequal clustering protocol (EADUC) is projected. The EADUC protocol is commonly used for solving energy [...]

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• Multiple-valued logic design based on the multiple-peak BiCMOS-NDR circuits

  K. Gan, J. Lu, W. Yeh, Y. Chen, Y. Chen

  Collection of Engineering Science and Technology, an International Journal (2017).

  
  

  Abstract

  Three different multiple-valued logic (MVL) designs using the multiple-peak negative-differential-resistance (NDR) circuits are investigated. The basic NDR element, which is made of several Si-based metal-oxide-semiconductor field-effect-transistor (MOS) and SiGe-based heterojunction-bipolar-transistor (HBT) devices, can be implemented by using a standard BiCMOS process. These MVL circuits are designed based on the triggering-pulse control, saw-tooth input signal, and peak-control methods, respectively. However, there are some transient states existing between the multiple stable levels for the first two methods. These states might affect the circuit function in practical application. As a result, our proposed peak-control method for the MVL design can be used to overcome these transient states.

  Abstract
  Three different multiple-valued logic (MVL) designs using the multiple-peak negative-differential-resistance (NDR) circuits are investigated. The basic NDR element, which [...]

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• Numerical study on flow separation in 90° pipe bend under high Reynolds number by k-ε modelling

  P. Dutta, S. Saha, N. Nandi, N. Pal

  Collection of Engineering Science and Technology, an International Journal (2017).

  
  

  Abstract

  The present paper makes an effort to find the flow separation characteristics under high Reynolds number in pipe bends. Single phase turbulent flow through pipe bends is investigated using k-ε turbulence model. After the validation of present model against existing experimental results, a detailed study has been performed to study the influence of Reynolds number on flow separation and reattachment. The separation region and the velocity field of the primary and the secondary flows in different sections have been illustrated. Numerical results show that flow separation can be clearly visualized for bend with low curvature ratio. Distributions of the velocity vector show the secondary motion clearly induced by the movement of fluid from inner to outer wall of the bend leading to flow separation. This paper provides numerical results to understand the flow characteristics of fluid flow in 90° bend pipe.

  Abstract
  The present paper makes an effort to find the flow separation characteristics under high Reynolds number in pipe bends. Single phase turbulent flow through pipe bends is investigated [...]

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