Journal of Engineering http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2016 , Hindawi Publishing Corporation . All rights reserved. Microcontroller Based Flexible Modulation Scheme of MLI Operation for Selective Lower Levels: A Knowledge Based Approach Wed, 04 May 2016 11:18:08 +0000 http://www.hindawi.com/journals/je/2016/9206124/ In today’s industrial world multilevel inverter (MLI) got a significant importance in medium voltage application and also a very potential topic for researchers. It is experienced that studying and comparing results of multilevel inverter (MLI) at distinct levels are a costlier and time consuming issue for any researcher if he fabricate different inverters for each level, as designing power modules simultaneously for different level is a cumbersome task. In this paper a flexible quotient has been proposed to recognize possible conversion of available MLI to few lower level inverters by appropriately changing microcontroller programming. This is an attempt to obtain such change in levels through simulation using MATLAB Simulink on inductive load which may also be applied to induction motor. Experimental results of pulse generation using dsPIC33EP256MC202 demonstrate the feasibility of proposed scheme. Proposed flexible quotient successfully demonstrates that a five-level inverter may be operated as three and two levels also. The paper focuses on odd levels only as common mode voltage (CMV) can be reduced to zero and performance of drives is better than even level. Simulated and experimental results are given in paper. R. K. Dhatrak, R. K. Nema, and D. M. Deshpande Copyright © 2016 R. K. Dhatrak et al. All rights reserved. Prediction of Load-Carrying Capacity in Steel Shear Wall with Opening Using Artificial Neural Network Tue, 03 May 2016 08:21:54 +0000 http://www.hindawi.com/journals/je/2016/4039407/ The effects of different parameters on steel plate shear wall (SPSW) are investigated. The studied parameters are thickness of plate, location of the opening, thickness of diagonal stiffeners, and thickness of circular stiffener. Load-carrying capacity of the SPSW is studied under static load using nonlinear geometrical and material analysis in ABAQUS and the obtained simulation results are verified. An artificial neural network (ANN) is proposed to model the effects of these parameters. According to the results the circular stiffener has more effect compared with the diagonal stiffeners. However, the thickness of the plate has the most significant effect on the SPSW behavior. The results show that the best place for the opening location is the center of SPSW. Multilayer perceptron (MLP) neural network was used to predict the maximum load in SPSW with opening. The predicted maximum load values using the proposed MLP model were compared with the simulated validated data. The obtained results show that the proposed ANN model has achieved good agreement with the validated simulated data, with correlation coefficient of more than 0.9975. Therefore, the proposed model is useful, reliable, fast, and cheap tools to predict the maximum load in SPSW. E. Khalilzadeh Vahidi and M. M. Roshani Copyright © 2016 E. Khalilzadeh Vahidi and M. M. Roshani. All rights reserved. Routing in Wireless Multimedia Sensor Networks: A Survey of Existing Protocols and Open Research Issues Mon, 18 Apr 2016 11:46:51 +0000 http://www.hindawi.com/journals/je/2016/9608757/ With the advancement of wireless sensor networks (WSNs) and technology, applicability of WSNs as a system is touching new heights. The development of multimedia nodes has led to the creation of another intelligent distributed system, which can transfer real-time multimedia traffic, ubiquitously. Wireless multimedia sensor networks (WMSNs) are applicable in a wide range of areas including area monitoring and video surveillance. But due to unreliable error-prone communication medium and application specific quality of service (QoS) requirements, routing of real-time multimedia traffic in WMSNs poses a serious problem. The paper discusses various existing routing strategies in WMSNs, with their properties and limitations which lead to open research issues. Further, detailed classification and analytical comparison of discussed protocols are also presented. Vikas Bhandary, Amita Malik, and Sanjay Kumar Copyright © 2016 Vikas Bhandary et al. All rights reserved. Interaction of Magnetic Field and Nonlinear Convection in the Stagnation Point Flow over a Shrinking Sheet Mon, 18 Apr 2016 07:11:47 +0000 http://www.hindawi.com/journals/je/2016/6752520/ The steady two-dimensional boundary layer stagnation point flow due to a shrinking sheet is analyzed. The combined effects of magnetic field and nonlinear convection are taken into account. The governing equations for the flow are modeled and then simplified using the similarity transformation and boundary layer approach. The numerical solution of the reduced equations is obtained by the second-order finite difference scheme also known as Keller box method. The influence of the pertinent parameters of the problem on velocity and temperature profiles, skin friction, and sheet temperature gradient are presented through the graphs and tables and discussed. The magnetic field and nonlinear convection parameters significantly enhance the solution range. Rakesh Kumar and Shilpa Sood Copyright © 2016 Rakesh Kumar and Shilpa Sood. All rights reserved. Slip Effect on MHD Chemically Reacting Convictive Boundary Layer Flow with Heat Absorption Mon, 11 Apr 2016 12:59:09 +0000 http://www.hindawi.com/journals/je/2016/2689493/ The aim of this paper is to investigate steady magneto micropolar fluid past a stretched semi-infinite vertical and permeable surface taking into account heat absorption, hall and ion-slip effect, first-order chemical reaction, and radiation effects. The system of coupled nonlinear equations is solved numerically and the effects of various parameters on the velocity, the microrotation, the temperature, and the concentration field are calculated. The following discovery was made: an increase in the hall parameter strongly enhances the fluid velocity, an increase in the heat absorption parameter increases the temperature, and an increase in the slip parameter decreases the velocity. Additionally, the local skin friction, Nusselt number, and Sherwood number are also analyzed for various parameters and presented in table form. Mekonnen Shifferaw Ayano and Negussie Tadege Demeke Copyright © 2016 Mekonnen Shifferaw Ayano and Negussie Tadege Demeke. All rights reserved. Sorption Profile of Phosphorus Ions onto ZnO Nanorods Synthesized via Sonic Technique Mon, 11 Apr 2016 09:16:43 +0000 http://www.hindawi.com/journals/je/2016/2308560/ High surface area zinc oxide material in nanorod morphological structure was synthesized using an ultrasonic technique in the presence of polyvinyl pyrrolidone as stabilizing agent. The crystallite, morphology, and surface area of the prepared white powder material were identified using XRD, SEM, and BET techniques, respectively. X-ray analysis confirms the high purity of synthesized ZnO. The evaluated specific surface area of prepared ZnO was 16.7 m2/g; this value guarantees high efficiency for water purification. The feasibility of synthesized ZnO nanorods for phosphorus sorption from aqueous solution was established using batch technique. Nano-zinc oxide exhibits high efficiency for phosphorus removal; the equilibrium state was recorded within 90 minutes. The most effective hydrogen ion concentration of the polluted solution was recorded at pH = 1 for phosphorus decontamination. The equilibrium of phosphorus sorption onto ZnO nanorods was well explained using both Langmuir and Temkin isotherm models. The calculated maximum monolayer sorption capacity was 89 mg/g according to Langmuir isotherm at 27°C. In order to explain the phosphorus sorption mechanism onto the prepared ZnO nanorods, three simplified kinetic models of pseudo-first order, pseudo-second order, and intraparticle diffusion rate models were tested. Kinetics was well fitted by pseudo-second order kinetic model with a contribution of intraparticle diffusion. M. F. Elkady, H. Shokry Hassan, and Eslam Salama Copyright © 2016 M. F. Elkady et al. All rights reserved. Machine Learning Based Statistical Prediction Model for Improving Performance of Live Virtual Machine Migration Sun, 10 Apr 2016 06:30:49 +0000 http://www.hindawi.com/journals/je/2016/3061674/ Service can be delivered anywhere and anytime in cloud computing using virtualization. The main issue to handle virtualized resources is to balance ongoing workloads. The migration of virtual machines has two major techniques: (i) reducing dirty pages using CPU scheduling and (ii) compressing memory pages. The available techniques for live migration are not able to predict dirty pages in advance. In the proposed framework, time series based prediction techniques are developed using historical analysis of past data. The time series is generated with transferring of memory pages iteratively. Here, two different regression based models of time series are proposed. The first model is developed using statistical probability based regression model and it is based on ARIMA (autoregressive integrated moving average) model. The second one is developed using statistical learning based regression model and it uses SVR (support vector regression) model. These models are tested on real data set of Xen to compute downtime, total number of pages transferred, and total migration time. The ARIMA model is able to predict dirty pages with 91.74% accuracy and the SVR model is able to predict dirty pages with 94.61% accuracy that is higher than ARIMA. Minal Patel, Sanjay Chaudhary, and Sanjay Garg Copyright © 2016 Minal Patel et al. All rights reserved. Application of Unit Commitment with Market Pool in a Peaking Power Generation Firm in the Philippines for a Cost Reduction Case Study Thu, 07 Apr 2016 11:50:41 +0000 http://www.hindawi.com/journals/je/2016/6105720/ This paper attempts to provide an optimum loading schedule of power generating units with the least cost by solving a unit commitment (UC) problem and to present good estimates of cost differences when UC problem is not applied. UC is a fundamental optimization problem of power generation systems which determines the optimum schedule of generating units which minimizes generation costs. However, for small power generation firms which are situated in developing countries, UC-based problems are poorly understood if not implemented and the scheduling of generating units is based on some methodologies which may provide results that are not optimal. Thus, a case study in a small power generation firm in central Philippines is carried out to elucidate these objectives. The case requires a solution of the mixed-integer nonlinear programming (MINLP) problem. Results show that the proposed UC-based problem yields optimal costs and the cost disparity from the current scheduling scheme is approximately at 27% which may be considered as potential cost savings. This shows that UC-based problem provides a reliable platform in achieving minimal generation costs. These results are significant to decision-makers particularly in small power generation firms and to engineering practitioners in the Philippines and in some developing countries as these provide an overview of the disparity of cost figures of not implementing UC. Luke Rey Santillan, Kenn Brylle Senen, Robert Wamilda Jr., Lanndon Ocampo, Rafael Seva Jr., Reuella J. Bacalso, and Alaine Liggayu Copyright © 2016 Luke Rey Santillan et al. All rights reserved. Early and Late Strength Characterization of Portland Cement Containing Calcined Low-Grade Kaolin Clay Mon, 04 Apr 2016 16:55:52 +0000 http://www.hindawi.com/journals/je/2016/7210891/ Heat treated low-grade kaolin clays are now considered as a suitable pozzolanic material to metakaolins. However their suitability as a good pozzolanic material depends on the geochemistry and structure of the clay which is usually influenced by the geographical environment. This study investigated a low-grade kaolin clay from Nyamebekyere in the Ashanti Region of Ghana. The influence of the calcined material on the early and late strength development of Portland cement was analyzed. The early 3- and 7-day strength as well as the late 28-day strength of Portland cement replaced with 20% by weight of the calcined material yielded the optimum strength values. Further analysis using Solid State Magic Angle Spinning Nuclear Magnetic Resonance (Ss MAS NMR) probed into the Aluminium (Al) environment to detect the presence and nature of Al hydrates using the optimum mixture proportion. The Ss MAS NMR results showed that the strength enhancement of the optimum mixture was due to the growth of stable monosulphate compounds at the octahedral environment resulting from metastable aluminate phases at the tetrahedral environment. For greater reliability on concrete strength performance, the study recommends the use of 20% calcined clay of Nyamebekyere clay as Portland cement replacement. Mark Bediako, S. K. Y. Gawu, A. A. Adjaottor, and John Solomon Ankrah Copyright © 2016 Mark Bediako et al. All rights reserved. Possibilities for Advanced Encoding Techniques at Signal Transmission in the Optical Transmission Medium Thu, 31 Mar 2016 11:42:24 +0000 http://www.hindawi.com/journals/je/2016/2385372/ This paper presents a possible simulation of negative effects in the optical transmission medium and an analysis for the utilization of different signal processing techniques at the optical signal transmission. An attention is focused on the high data rate signal transmission in the optical fiber influenced by linear and nonlinear environmental effects presented by the prepared simulation model. The analysis includes possible utilization of OOK, BPSK, DBPSK, BFSK, QPSK, DQPSK, 8PSK, and 16QAM modulation techniques together with RS, BCH, and LDPC encoding techniques for the signal transmission in the optical fiber. Moreover, the prepared simulation model is compared with real optical transmission systems. In the final part, a comparison of the selected modulation techniques with different encoding techniques and their implementation in real transmission systems is shown. Filip Čertík and Rastislav Róka Copyright © 2016 Filip Čertík and Rastislav Róka. All rights reserved. A Higher-Order Thermomechanical Vibration Analysis of Temperature-Dependent FGM Beams with Porosities Tue, 29 Mar 2016 12:43:25 +0000 http://www.hindawi.com/journals/je/2016/9561504/ In the present paper, thermomechanical vibration characteristics of functionally graded (FG) Reddy beams made of porous material subjected to various thermal loadings are investigated by utilizing a Navier solution method for the first time. Four types of thermal loadings, namely, uniform, linear, nonlinear, and sinusoidal temperature rises, through the thickness direction are considered. Thermomechanical material properties of FG beam are assumed to be temperature-dependent and supposed to vary through thickness direction of the constituents according to power-law distribution (P-FGM) which is modified to approximate the porous material properties with even and uneven distributions of porosities phases. The governing differential equations of motion are derived based on higher order shear deformation beam theory. Hamilton’s principle is applied to obtain the governing differential equations of motion which are solved by employing an analytical technique called the Navier type solution method. Influences of several important parameters such as power-law exponents, porosity distributions, porosity volume fractions, thermal effects, and slenderness ratios on natural frequencies of the temperature-dependent FG beams with porosities are investigated and discussed in detail. It is concluded that these effects play significant role in the thermodynamic behavior of porous FG beams. Farzad Ebrahimi and Ali Jafari Copyright © 2016 Farzad Ebrahimi and Ali Jafari. All rights reserved. Case Study: LCA Methodology Applied to Materials Management in a Brazilian Residential Construction Site Mon, 28 Mar 2016 10:29:13 +0000 http://www.hindawi.com/journals/je/2016/8513293/ The construction industry is increasingly concerned with improving the social, economic, and environmental indicators of sustainability. More than ever, the growing demand for construction materials reflects increased consumption of raw materials and energy, particularly during the phases of extraction, processing, and transportation of materials. This work aims to help decision-makers and to promote life cycle thinking in the construction industry. For this purpose, the life cycle assessment (LCA) methodology was chosen to analyze the environmental impacts of building materials used in the construction of a residence project in São Gonçalo, Rio de Janeiro, Brazil. The LCA methodology, based on ISO 14040 and ISO 14044 guidelines, is applied with available databases and the SimaPro program. As a result, this work shows that there is a substantial waste of nonrenewable energy, increasing global warming and harm to human health in this type of construction. This study also points out that, for this type of Brazilian construction, ceramic materials account for a high percentage of the mass of a total building and are thus responsible for the majority of environmental impacts. João de Lassio, Josué França, Kárida Espirito Santo, and Assed Haddad Copyright © 2016 João de Lassio et al. All rights reserved. Modeling of the Strain Rate Dependency of Polycarbonate’s Yield Stress: Evaluation of Four Constitutive Equations Mon, 14 Mar 2016 08:19:20 +0000 http://www.hindawi.com/journals/je/2016/6315421/ The main focus of this paper is in evaluating four constitutive relations which model the strain rate dependency of polymers yield stress. Namely, the two-term power-law, the Ree-Eyring, the cooperative, and the newly modified-Eyring equations are used to fit tensile and compression yield stresses of polycarbonate, which are obtained from the literature. The four equations give good agreement with the experimental data. Despite using only three material constants, the modified-Eyring equation, which considers a strain rate-dependent activation volume, gives slightly worse fit than the three other equations. The two-term power-law and the cooperative equation predict a progressive increase in the strain rate sensitivity of the yield stress. Oppositely, the Ree-Eyring and the modified-Eyring equations show a clear transition between the low and high strain rate ranges. Namely, they predict a linear dependency of the yield stress in terms of the strain rate at the low strain rate range. Crossing a threshold strain rate, the yield stress sensitivity sharply increases as the strain rate increases. Hence, two different behaviors were observed though the four equations fit well the experimental data. More experimental data, mainly at the intermediate strain rate range, are needed to conclude which, of the two behaviors, is more appropriate for polymers. Abdullah A. Al-Juaid and Ramzi Othman Copyright © 2016 Abdullah A. Al-Juaid and Ramzi Othman. All rights reserved. Sediment and Cavitation Erosion Studies through Dam Tunnels Sun, 13 Mar 2016 14:33:23 +0000 http://www.hindawi.com/journals/je/2016/8645789/ This paper presents results of sediment and cavitation erosion through Tunnel 2 and Tunnel 3 of Tarbela Dam in Pakistan. Main bend and main branch of Tunnel 2 and outlet 1 and outlet 3 of Tunnel 3 are concluded to be critical for cavitation and sediment erosion. Studies are also performed for increased sediments flow rate, concluding 5 kg/sec as the critical value for sudden increase in erosion rate density. Erosion rate is concluded to be the function of sediment flow rate and head condition. Particulate mass presently observed is reasonably low, hence presently not affecting the velocity and the flow field. Muhammad Abid, Jamal Saeed, and Hafiz Abdul Wajid Copyright © 2016 Muhammad Abid et al. All rights reserved. Using GIS-Based Tools for the Optimization of Solid Waste Collection and Transport: Case Study of Sfax City, Tunisia Thu, 10 Mar 2016 08:46:41 +0000 http://www.hindawi.com/journals/je/2016/4596849/ Expenditure for waste collection and transport in Tunisia constitutes 75–100% of the total solid waste management budget. In this study, optimized scenarios were developed using ArcGIS Network Analyst tool in order to improve the efficiency of waste collection and transportation in the district Cité El Habib of Sfax city, Tunisia. Geographic Information System (GIS) was created based on data collection and GPS tracking (collection route/bins position). The actual state (Scenario S0) was evaluated, and by modifying its particular parameters, other scenarios were generated and analyzed to identify optimal routes: S1, route optimized with the same working resources (change of stops sequencing only); S2, route optimized with change of vehicles; and S3, route optimized with change of collection method (vehicles and reallocation of bins). The results showed that the three scenarios guarantee savings compared to S0 in terms of collection time (14%, 57%, and 57% for S1, S2, and S3, resp.) and distance (13.5%, 13.5%, and 40.5% for S1, S2, and S3, resp.). Thus, a direct impact on fuel consumption can be expected with savings of 16%, 20%, and 48% for S1, S2, and S3, respectively, without mentioning the additional benefits related to CO2 emissions, hours of work, vehicles wear/maintenance, and so forth. Amjad Kallel, Mohamed Moncef Serbaji, and Moncef Zairi Copyright © 2016 Amjad Kallel et al. All rights reserved. A High Rated Solar Water Distillation Unit for Solar Homes Wed, 09 Mar 2016 10:00:06 +0000 http://www.hindawi.com/journals/je/2016/7937696/ India is presently focusing on complete utilization of solar energy and saving fossil fuels, which are limited. Various solar energy systems like solar cookers, solar water heaters, solar lanterns, solar PV lights, and solar lamps are continuously availing by the people of India at a low cost and on good subsidies. Apart from this, India is a solar energy promising country with a good number of solar homes (carrying solar energy systems) in its various locations. The present paper focuses on a unique combination of solar dish cooker (SDC) and solar water heater (SWH) to produce distilled water with a high distillate and a high daily productivity. The procedure has been discussed on the basis of experimental testing to produce distilled water by combining an evacuated type SWH and a SDC. Experimentation has been carried out in MIT, Moradabad (longitude, 28.83°N, and latitude, 78.78°E) by developing the same experimental setup on behalf of solar homes. The daily productivity of distilled water was found around 3.66 litres per day in full sunshine hours for an approximated pH value of 7.7 and a ppm value of 21. The payback period (PBP) has been estimated around 1.16 years of the present system. Abhishek Saxena and Navneet Deval Copyright © 2016 Abhishek Saxena and Navneet Deval. All rights reserved. Sorption of Uranium Ions from Their Aqueous Solution by Resins Containing Nanomagnetite Particles Mon, 07 Mar 2016 11:29:37 +0000 http://www.hindawi.com/journals/je/2016/7214348/ Magnetic amine resins composed of nanomagnetite (Fe3O4) core and glycidyl methacrylate (GMA)/N,N′-methylenebisacrylamide (MBA) shell were prepared by suspension polymerization of glycidyl methacrylate with N,N′-methylenebisacrylamide in the presence of nanomagnetite particles and immobilized with different amine ligands. These resins showed good magnetic properties and could be easily retrieved from their suspensions using an external magnetic field. Adsorption behaviors of uranium ions on the prepared resins were studied. Maximum sorption capacities of uranium ions on R-1 and R-2 were found to be 92 and 158 mg/g. Uranium was extracted successfully from three granite samples collected from Gabal Gattar pluton, North Eastern Desert, Egypt. The studied resins showed good durability and regeneration using HNO3. Mahmoud O. Abd El-Magied Copyright © 2016 Mahmoud O. Abd El-Magied. All rights reserved. Secure Trust Based Key Management Routing Framework for Wireless Sensor Networks Wed, 02 Mar 2016 12:00:52 +0000 http://www.hindawi.com/journals/je/2016/2089714/ Security is always a major concern in wireless sensor networks (WSNs). Several trust based routing protocols are designed that play an important role in enhancing the performance of a wireless network. However they still have some disadvantages like limited energy resources, susceptibility to physical capture, and little protection against various attacks due to insecure wireless communication channels. This paper presents a secure trust based key management (STKF) routing framework that establishes a secure trustworthy route depending upon the present and past node to node interactions. This route is then updated by isolating the malicious or compromised nodes from the route, if any, and a dedicated link is created between every pair of nodes in the selected route with the help of “” composite random key predistribution scheme (RKPS) to ensure data delivery from source to destination. The performance of trust aware secure routing framework (TSRF) is compared with the proposed routing scheme. The results indicate that STKF provides an effective mechanism for finding out a secure route with better trustworthiness than TSRF which avoids the data dropping, thereby increasing the data delivery ratio. Also the distance required to reach the destination in the proposed protocol is less hence effectively utilizing the resources. Jugminder Kaur, Sandeep S. Gill, and Balwinder S. Dhaliwal Copyright © 2016 Jugminder Kaur et al. All rights reserved. Unsteady MHD Mixed Convection Flow of Chemically Reacting Micropolar Fluid between Porous Parallel Plates with Soret and Dufour Effects Mon, 29 Feb 2016 14:42:03 +0000 http://www.hindawi.com/journals/je/2016/6531948/ The objective of the present study is to investigate the first-order chemical reaction and Soret and Dufour effects on an incompressible MHD combined free and forced convection heat and mass transfer of a micropolar fluid through a porous medium between two parallel plates. Assume that there are a periodic injection and suction at the lower and upper plates. The nonuniform temperature and concentration of the plates are assumed to be varying periodically with time. A suitable similarity transformation is used to reduce the governing partial differential equations into nonlinear ordinary differential equations and then solved numerically by the quasilinearization method. The fluid flow and heat and mass transfer characteristics for various parameters are analyzed in detail and shown in the form of graphs. It is observed that the concentration of the fluid decreases whereas the temperature of the fluid enhances with the increasing of chemical reaction and Soret and Dufour parameters. Odelu Ojjela and N. Naresh Kumar Copyright © 2016 Odelu Ojjela and N. Naresh Kumar. All rights reserved. Composition Design and Fatigue Curves of Hardfacing Materials for Cold Roll Mon, 29 Feb 2016 09:27:33 +0000 http://www.hindawi.com/journals/je/2016/8487976/ In order to improve the fatigue life of cold rolls, a series of hardfacing alloys were designed by orthogonal experiments considering the interaction between carbon, chromium, and niobium. Hardfacing layers were produced by Tungsten Inert Gas (TIG) arc welding. The effects of alloy content on microstructure and carbides and fatigue behavior at different load frequency and different temperature were analyzed. The results show that suitable combination of 0.5% C, 4.0% Cr, and 2.0% Nb can obtain a high hardness of 54.7 HRC for the formation of fine lath martensite and carbides with dispersed distribution. The new designed hardfacing materials have similar curves with parent material in low load frequency and below 400°C. C. L. Chen, C. X. Chen, Z. H. Guo, J. Ding, X. Han, and Q. Jiang Copyright © 2016 C. L. Chen et al. All rights reserved. Combined Experimental and CFD Investigation of the Parabolic Shaped Solar Collector Utilizing Nanofluid (CuO-H2O and SiO2-H2O) as a Working Fluid Sun, 28 Feb 2016 11:39:38 +0000 http://www.hindawi.com/journals/je/2016/5729576/ Nanoscience application plays a major role in heat transfer related problems. A nanofluid is basically a suspension of fine sized nanomaterials in base fluids like water, Therminol VP-1, ethylene glycol, and other heat transfer fluids. This paper evaluates the possible application of nanofluid in parabolic shaped concentrating solar collector using both experimental and CFD analysis. Different types of nanomaterials used are SiO2 and CuO of 20 nm average size. Nanofluids of SiO2-H2O (DI) and CuO-H2O (DI) of 0.01% volume concentration are used. Flow rates of 40 LPH and 80 LPH are used. ANSYS FLUENT 14.5 is used for carrying out CFD investigation. 3D temperature distribution of absorber tube is obtained using numerical investigation and the result is compared with the experimental one. Improvement in efficiency of collector of about 6.68% and 7.64% is obtained using 0.01% vol. conc. SiO2-H2O (DI) nanofluid and 0.01% vol. conc. CuO-H2O (DI) nanofluid, respectively, as compared to H2O (DI) at 40 LPH while at 80 LPH improvement in efficiency of collector of about 7.15% and 8.42% is obtained using 0.01% vol. conc. SiO2-H2O (DI) nanofluid and 0.01% vol. conc. CuO-H2O (DI) nanofluid, respectively, as compared to H2O (DI). Both experimental and CFD temperature results are in good agreement. Ketan Ajay and Lal Kundan Copyright © 2016 Ketan Ajay and Lal Kundan. All rights reserved. Power Consumption, Mixing Time, and Oxygen Mass Transfer in a Gas-Liquid Contactor Stirred with a Dual Impeller for Different Spacing Mon, 22 Feb 2016 13:21:00 +0000 http://www.hindawi.com/journals/je/2016/3954305/ Multiple or dual impellers are widely implemented in stirred contactors used in various biological processes like fermentation, water treatment, and pharmaceutical production. The spacing between impellers is considered as a crucial factor in designing of these types of contactors resulting in variation of oxygen mass transfer, mixing time, or power consumption for such biological system. A study of three parts was conducted to characterize the effect of the spacing between impellers on the most important parameters that related to biological contactor performance: oxygen mass transfer coefficient from the gas phase (air) to the liquid phase (water), mixing time, and power consumption for different operating rotational speeds (1.67–3.33 rps) and for three different spacing positions. The used impellers system in the study is a dual impeller system which consists of an inverted and bladed rotated cone (IBRC) and a pitched-blade up-flow propeller (PBPU). The experimental results showed that the shorter spacing (the lower PBPU in a higher position) is more convenient, as the achieved oxygen mass transfer coefficient has showed an improvement in its values with lower mixing time and with a slight alteration in power consumption. Hayder Mohammed Issa Copyright © 2016 Hayder Mohammed Issa. All rights reserved. Optimization of Alkali Catalyzed Transesterification of Safflower Oil for Production of Biodiesel Wed, 17 Feb 2016 09:29:54 +0000 http://www.hindawi.com/journals/je/2016/8928673/ The Central Composite Design is used for the optimization of alkaline catalyzed transesterification parameters such as methanol quantity, catalytic concentration, and rotational speed by keeping the temperature and reaction time constant. The Central Composite Design method is employed to get the maximum safflower oil methyl ester yield. The combined effects of catalyst concentration, rotational speed, and molar ratio of alcohol to oil were investigated and optimized using response surface methodology. A statistical model has predicted the maximum yield of safflower oil methyl ester (94.69% volume of oil) parameters such as catalyst concentration (0.6 grams), methanol amount (30 mL), rotational speed (600 rpm), and keeping constant reaction temperature (55°C to 65°C) and reaction time (60 minutes). Experimental maximum yield of 91.66% was obtained at above parameters. XLSTAT is used to generate a linear model to predict the methyl ester yield as a function of methanol quantity, catalyst concentration, and rotational speed by keeping constant reaction temperature (55°C to 65°C) and reaction time (60 minutes). MINITAB is used to draw the 3D response surface plot and 2D contour plot to predict the maximum biodiesel yield. M. C. Math and K. N. Chandrashekhara Copyright © 2016 M. C. Math and K. N. Chandrashekhara. All rights reserved. A Defected Structure Shaped CPW-Fed Wideband Microstrip Antenna for Wireless Applications Wed, 17 Feb 2016 08:19:11 +0000 http://www.hindawi.com/journals/je/2016/2863508/ A coplanar waveguide- (CPW-) fed compact wideband defected structure shaped microstrip antenna is proposed for wireless applications. Defected structure is produced by cutting the shape antenna in the form of two-sided T shape. The proposed antenna consists of two-sided shape strip as compared to usual monopole patch antenna for minimizing the height of the antenna. The large space around the radiator is fully utilized as the ground is on the same plane as of radiator. Microstrip line feed is used to excite the proposed antenna placed on an FR4 substrate (dielectric constant ). The antenna is practically fabricated and simulated. Simulated results of the proposed antenna have been obtained by using Ansoft High-Frequency Structure Simulator (HFSS) software. These results are compared with measured results by using network analyzer. Measured result shows good agreement with the simulated results. It is observed that the proposed antenna shows a wideband from 2.96 GHz to 7.95 GHz with three bands at  GHz,  GHz, and  GHz. Puneet Khanna, Amar Sharma, Kshitij Shinghal, and Arun Kumar Copyright © 2016 Puneet Khanna et al. All rights reserved. Modified SIFT Descriptors for Face Recognition under Different Emotions Thu, 11 Feb 2016 12:07:56 +0000 http://www.hindawi.com/journals/je/2016/9387545/ The main goal of this work is to develop a fully automatic face recognition algorithm. Scale Invariant Feature Transform (SIFT) has sparingly been used in face recognition. In this paper, a Modified SIFT (MSIFT) approach has been proposed to enhance the recognition performance of SIFT. In this paper, the work is done in three steps. First, the smoothing of the image has been done using DWT. Second, the computational complexity of SIFT in descriptor calculation is reduced by subtracting average from each descriptor instead of normalization. Third, the algorithm is made automatic by using Coefficient of Correlation (CoC) instead of using the distance ratio (which requires user interaction). The main achievement of this method is reduced database size, as it requires only neutral images to store instead of all the expressions of the same face image. The experiments are performed on the Japanese Female Facial Expression (JAFFE) database, which indicates that the proposed approach achieves better performance than SIFT based methods. In addition, it shows robustness against various facial expressions. Nirvair Neeru and Lakhwinder Kaur Copyright © 2016 Nirvair Neeru and Lakhwinder Kaur. All rights reserved. Cement Stabilized Soil Blocks Admixed with Sugarcane Bagasse Ash Wed, 10 Feb 2016 13:49:31 +0000 http://www.hindawi.com/journals/je/2016/7940239/ The study involved investigating the performance of ordinary Portland cement (OPC) stabilized soil blocks amended with sugarcane bagasse ash (SBA). Locally available soil was tested for its properties and characterized as clay of medium plasticity. This soil was stabilized using 4% and 10% OPC for manufacture of blocks of size 19 cm × 9 cm × 9 cm. The blocks were admixed with 4%, 6%, and 8% SBA by weight of dry soil during casting, with plain OPC stabilized blocks acting as control. All blocks were cast to one target density and water content followed by moist curing for a period of 28 days. They were then subjected to compressive strength, water absorption, and efflorescence tests in accordance with Bureau of Indian standards (BIS) specifications. The results of the tests indicated that OPC stabilization resulted in blocks that met the specifications of BIS. Addition of SBA increased the compressive strength of the blocks and slightly increased the water absorption but still met the standard requirement of BIS code. It is concluded that addition of SBA to OPC in stabilized block manufacture was capable of producing stabilized blocks at reduced OPC content that met the minimum required standards. Jijo James, P. Kasinatha Pandian, K. Deepika, J. Manikanda Venkatesh, V. Manikandan, and P. Manikumaran Copyright © 2016 Jijo James et al. All rights reserved. Numerical Study of Mixed Convection of the Nanofluids in Two-Sided Lid-Driven Square Cavity with a Pair of Triangular Heating Cylinders Mon, 08 Feb 2016 07:52:28 +0000 http://www.hindawi.com/journals/je/2016/8962091/ A numerical study is carried out concerning mixed convection of the nanofluid in two-sided lid-driven square cavity with a pair of triangular heat sources. The upper and bottom moving walls are thermally insulated while the left and right walls are cooled at constant temperature. Two-dimensional Navier-Stokes and energy equations are solved using the finite volume discretization method with SIMPLE algorithm. The method used is validated against previous works. Two cases were considered depending on the direction of moving walls. Effects of various design parameters such as Richardson number , nanoparticle volume fraction , and size and type of nanoparticles on the heat transfer rate are investigated. The results of this investigation illustrate that, by reducing the diameter of the nanoparticles and , the heat transfer rate increases. Moreover, it is found that by changing horizontal direction of the moving walls the heat transfer rate variation is negligible. Zoubair Boulahia, Abderrahim Wakif, and Rachid Sehaqui Copyright © 2016 Zoubair Boulahia et al. All rights reserved. Study of Thermal Properties of Mixed (PP/EPR)/ABS with Five Model Compatibilizers Thu, 28 Jan 2016 13:50:33 +0000 http://www.hindawi.com/journals/je/2016/8539694/ The influences of incorporating compatibilizers E-EA-MAH, E-MA-GMA, E-AM, SEBS KRATON G, or PP-g-MAH on the thermal properties of mixed (polypropylene/ethylene propylene rubber)/acrylonitrile butadiene styrene (PP/EPR)/ABS have been investigated. DSC investigations have revealed that the incorporation of 5% of ABS in the copolymer (PP/EPR) does not fundamentally affect the thermal properties of the basic copolymer; additionally, the addition of 1.5% of each of the compatibilizers in the basic mixture does not significantly alter the crystallization temperature values and the melting of the -P- sequences. There is a variation of melting enthalpy values of the -P- sequences of 18.23% using SEBS KRATON G and of 10.38% using E-AM-GMA. When the rate of each of the compatibilizers increases to 5%, overall crystallization enthalpies of -P- sequences are almost kept unchanged, except for the case of using the compatibilizer E-AM-GMA with a variation of 8.42%. There is a minor variation of the melting enthalpy of -P- sequences with higher levels of compatibilizer. The incorporation of 5% ABS copolymer in the PP/EPR does not significantly alter the thermal properties of the basic structure of (PP/EPR)/ABS. Pierre Marcel Anicet Noah, Louis-Max Ayina Ohandja, Rolant Eba Medjo, Salem Chabira, Fabien Betene Ebanda, and Patrick Anyouzoa Ondoua Copyright © 2016 Pierre Marcel Anicet Noah et al. All rights reserved. Nonuniform Illumination Correction Algorithm for Underwater Images Using Maximum Likelihood Estimation Method Wed, 27 Jan 2016 14:07:08 +0000 http://www.hindawi.com/journals/je/2016/5718297/ Scattering and absorption of light is main reason for limited visibility in water. The suspended particles and dissolved chemical compounds in water are also responsible for scattering and absorption of light in water. The limited visibility in water results in degradation of underwater images. The visibility can be increased by using artificial light source in underwater imaging system. But the artificial light illuminates the scene in a nonuniform fashion. It produces bright spot at the center with the dark region at surroundings. In some cases imaging system itself creates dark region in the image by producing shadow on the objects. The problem of nonuniform illumination is neglected by the researchers in most of the image enhancement techniques of underwater images. Also very few methods are discussed showing the results on color images. This paper suggests a method for nonuniform illumination correction for underwater images. The method assumes that natural underwater images are Rayleigh distributed. This paper used maximum likelihood estimation of scale parameter to map distribution of image to Rayleigh distribution. The method is compared with traditional methods for nonuniform illumination correction using no-reference image quality metrics like average luminance, average information entropy, normalized neighborhood function, average contrast, and comprehensive assessment function. Sonali Sachin Sankpal and Shraddha Sunil Deshpande Copyright © 2016 Sonali Sachin Sankpal and Shraddha Sunil Deshpande. All rights reserved. Hybrid Dynamic MCML Style: A High Speed Dynamic MCML Style Wed, 27 Jan 2016 12:33:24 +0000 http://www.hindawi.com/journals/je/2016/8027150/ This paper proposes hybrid dynamic current mode logic (H-DyCML) as an alternative to existing dynamic CML (DyCML) style for digital circuit design in mixed-signal applications. H-DyCML introduces complementary pass transistors for implementation of logic functions. This allows reduction in the stacked source-coupled transistor pair levels in comparison to the existing DyCML style. The resulting reduction in transistor pair levels permits significant speed improvement. SPICE simulations using TSMC 180 nm and 90 nm CMOS technology parameters are carried out to verify the functionality and to identify their advantages. Some issues related to the compatibility of the complementary pass transistor logic have been investigated and the appropriate solutions have been proposed. The performance of the proposed H-DyCML gates is compared with the existing DyCML gates. The comparison confirms that proposed H-DyCML gates is faster than the existing DyCML gates. Neeta Pandey, Damini Garg, Kirti Gupta, and Bharat Choudhary Copyright © 2016 Neeta Pandey et al. All rights reserved.