Journal of Engineering The latest articles from Hindawi Publishing Corporation © 2016 , Hindawi Publishing Corporation . All rights reserved. Modified SIFT Descriptors for Face Recognition under Different Emotions Thu, 11 Feb 2016 12:07:56 +0000 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 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 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 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 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 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. Experimental Investigation of Mechanical Properties of PVC Polymer under Different Heating and Cooling Conditions Tue, 26 Jan 2016 11:47:28 +0000 Due to a widely increasing usage of polymers in various industrial applications, there should be a continuous need in doing research investigations for better understanding of their properties. These applications require the usage of the polymer in different working environments subjecting the material to various temperature ranges. In this paper, an experimental investigation of mechanical properties of polyvinyl chloride (PVC) polymer under heating and cooling conditions is presented. For this purpose standard samples are prepared and tested in laboratory using universal material testing apparatus. The samples are tested under different conditions including the room temperature environment, cooling in a refrigerator, and heating at different heating temperatures. It is observed that the strength of the tested samples decreases with the increasing of heating temperature and accordingly the material becomes softer. Meanwhile the cooling environments give a clear increasing to the strength of the material. Sarkawt Rostam, Alan Kareem Ali, and Firdaws Haidar AbdalMuhammad Copyright © 2016 Sarkawt Rostam et al. All rights reserved. Is Urbanisation Rate a Feasible Supplemental Parameter in Forecasting Electricity Consumption in China? Wed, 20 Jan 2016 14:02:47 +0000 Traditional method of forecasting electricity consumption based only on GDP was sometimes ineffective. In this paper, urbanisation rate (UR) was introduced as an additional predictor to improve the electricity demand forecast in China at provincial scale, which was previously based only on GDP. Historical data of Shaanxi province from 2000 to 2013 was collected and used as case study. Four regression models were proposed and GDP, UR, and electricity consumption (EC) were used to establish the parameters in each model. The model with least average error of hypothetical forecast results in the latest three years was selected as the optimal forecast model. This optimal model divides total EC into four parts, of which forecasts can be made separately. It was found that GDP was only better correlated than UR on household EC, whilst UR was better on the three sectors of industries. It was concluded that UR is a valid predictor to forecast electricity demand at provincial level in China nowadays. Being provided the planned value of GDP and UR from the government, EC in 2015 were forecasted as 131.3 GWh. Biao Yang, Yingcheng Li, Haokun Wei, and Huan Lu Copyright © 2016 Biao Yang et al. All rights reserved. Maximizing the Sustainability of Cement Utilization in Building Projects through the Use of Greener Materials Tue, 19 Jan 2016 13:22:18 +0000 Greener technologies and sustainable developments are currently among the main tools used by many industries in shaping the world for a better future. The construction industry that is known to have numerous negative impact on sustainability is now wide awake on sustainable measures which can aid in reducing its negative impact. In this work, green cement was produced from pyroprocessed clay (PC) at 800°C and mixed together with Portland cement. This paper presents both laboratory tests and some field applications of green cement application. Laboratory tests performed included setting times, compressive strength, and shrinkage. Field applications of the green cement are shown. Results from the work showed that well-proportioned greener cement gained strengths between 11% and 30% more than Portland cement at standard curing period of 3, 7, 14, and 28 days. However, in real statistical terms, there was no difference between Portland cement and green cement strength performance. Shrinkage from both total and autogenous tests also showed insignificant differences between the two cements. The study recommends the use of green cements with pozzolanic origin than only Portland cement as a way to maximize sustainability in building projects. Mark Bediako, Charles Dela Adobor, Eric Opoku Amankwah, Kofi Nyako, and Charles Kwame Kankam Copyright © 2016 Mark Bediako et al. All rights reserved. An Experimental Study for Quantitative Estimation of Rebar Corrosion in Concrete Using Ground Penetrating Radar Mon, 18 Jan 2016 16:26:40 +0000 Corrosion of steel rebar in reinforced concrete is one the most important durability issues in the service life of a structure. In this paper, an investigation is conducted to find out the relationship between the amount of reinforced concrete corrosion and GPR maximum positive amplitude. Accelerated corrosion was simulated in the lab by impressing direct current into steel rebar that was submerged in a 5% salt water solution. The amount of corrosion was varied in the rebars with different levels of mass loss ranging from 0% to 45%. The corroded rebars were then placed into three different oil emulsion tanks having different dielectric properties similar to concrete. The maximum amplitudes from the corroded bars were recorded. A linear relationship between the maximum positive amplitudes and the amount of corrosion in terms of percentage loss of area was observed. It was proposed that the relationship between the GPR maximum amplitude and the amount of corrosion can be used as a basis of a NDE technique of quantitative estimation of corrosion. Md Istiaque Hasan and Nur Yazdani Copyright © 2016 Md Istiaque Hasan and Nur Yazdani. All rights reserved. Review on Pervaporation: Theory, Membrane Performance, and Application to Intensification of Esterification Reaction Mon, 28 Dec 2015 07:30:52 +0000 The esterification reaction is reversible and has low yield. In order to increase the yield of reaction, it is required to simultaneously remove the product of reaction. For this membranes are the viable approach. Pervaporation membranes have success in removal of components in dilute forms. Membrane performance is represented in terms of flux, sorption coefficient, separation factor, and permeance. These factors are related to the thickness of membrane, temperature, and feed concentration. Higher flux is observed at lower membrane thickness and higher feed concentration of water and lower selectivity is observed at higher temperatures due to increased free volume, lower viscosity, and higher feed side pressure. Different factors affect the pervaporation aided esterification reactor setup such as effect of initial molar ratios of the reactants, effect of catalyst concentration, effect of membrane area, and effect of temperature. Large membrane size could provide higher surface for the transfer of acid, though the challenges of membrane rupture do surround the studies. In the present review work, we tried to collaborate the works in totality of the pervaporation design starting from the membrane behavior to the process behavior. Different prospective fields are also explored which need investigation. Ghoshna Jyoti, Amit Keshav, and J. Anandkumar Copyright © 2015 Ghoshna Jyoti et al. All rights reserved. Comparative Kinetic Study of Anaerobic Treatment of Thermally Pretreated Source-Sorted Organic Market Refuse Thu, 24 Dec 2015 07:51:20 +0000 The present study deals with extensive investigations of the effect of thermal pretreatment on whole-sale market rejects for their biogas production potential. Market reject considered as biomass for this study has been treated at two different temperatures 85°C and 135°C for 8 h each and subjected as feedstock for anaerobic digestion (AD) process. The AD process has been operated in the mesophilic range (35–38°C) of bacterial growth. Various kinetic models have been used to simulate the experimental data. Kinetic modeling revealed that biogas production rate exhibited better coefficient of determination () in the range of 0.973–0.989 with exponential model for the ascending limb whereas the descending limb resulted in good linear correlation with as 0.911–0.976. Logistic growth model and Gompertz relation simulation of cumulative biogas production resulted in better values in the range of 0.994–0.997 and 0.998–0.999, whereas the values for exponential rise to maximum plots ranged from 0.722 to 0.800. Aritra Das and Chanchal Mondal Copyright © 2015 Aritra Das and Chanchal Mondal. All rights reserved. Experimental Study of Stabilized Soil Utilizing Circulating Fluidized Bed Combustion Desulfurization Ash with Carbide Slag and Desulfurization Gypsum Tue, 15 Dec 2015 12:23:36 +0000 This paper discusses the feasibility of preparing soil stabilizer which is circulating fluidized bed combustion ash-based, supplemented with carbide slag and desulfurization gypsum, composed entirely of complete industrial wastes. The results show that CFBC ash has better pozzolanic activity than fly ash. When stabilizer total content is 10% and the ratio of CFBC ash : carbide slag : desulfurization gypsum is 7.2 : 1.8 : 1, compressive strength of stabilized soil can reach the maximum of 2.12 MPa at the age of 28 d of curing. Stabilizer can meet the strength requirements of cement-soil mixing pile composite foundation and cement-soil mixing pile waterproof curtain. Dezhi Shao, Jinlong Liu, and Xin Huang Copyright © 2015 Dezhi Shao et al. All rights reserved. Aerodynamic Drag Reduction for a Generic Truck Using Geometrically Optimized Rear Cabin Bumps Thu, 10 Dec 2015 13:49:29 +0000 The continuous surge in gas prices has raised major concerns about vehicle fuel efficiency, and drag reduction devices offer a promising strategy. In this paper, we investigate the mechanisms by which geometrically optimized bumps, placed on the rear end of the cabin roof of a generic truck, reduce aerodynamic drag. The incorporation of these devices requires proper choices of the size, location, and overall geometry. In the following analysis we identify these factors using a novel methodology. The numerical technique combines automatic modeling of the add-ons, computational fluid dynamics and optimization using orthogonal arrays, and probabilistic restarts. Numerical results showed reduction in aerodynamic drag between 6% and 10%. Abdellah Ait Moussa, Justin Fischer, and Rohan Yadav Copyright © 2015 Abdellah Ait Moussa et al. All rights reserved. Flow over Exponentially Stretching Sheet through Porous Medium with Heat Source/Sink Tue, 17 Nov 2015 13:07:46 +0000 An attempt has been made to study the heat and mass transfer effect in a boundary layer MHD flow of an electrically conducting viscous fluid subject to transverse magnetic field on an exponentially stretching sheet through porous medium. The effect of thermal radiation and heat source/sink has also been discussed in this paper. The governing nonlinear partial differential equations are transformed into a system of coupled nonlinear ordinary differential equations and then solved numerically using a fourth-order Runge-Kutta method with a shooting technique. Graphical results are displayed for nondimensional velocity, temperature, and concentration profiles while numerical values of the skin friction local Nusselt number and Sherwood number are presented in tabular form for various values of parameters controlling the flow system. I. Swain, S. R. Mishra, and H. B. Pattanayak Copyright © 2015 I. Swain et al. All rights reserved. Deformation Behavior of Press Formed Shell by Indentation and Its Numerical Simulation Thu, 08 Oct 2015 13:18:22 +0000 Deformation behavior and energy absorbing performance of the press formed aluminum alloy A5052 shells were investigated to obtain the basic information regarding the mutual effect of the shell shape and the indentor. Flat top and hemispherical shells were indented by the flat- or hemispherical-headed indentor. Indentation force in the rising stage was sharper for both shell shapes when the flat indentor was used. Remarkable force increase due to high in-plane compressive stress arisen by the appropriate tool constraint was observed in the early indentation stage, where the hemispherical shell was deformed with the flat-headed indentor. This aspect is preferable for energy absorption performance per unit mass. Less fluctuation in indentation force was achieved in the combination of the hemispherical shell and similar shaped indentor. The consumed energy in the travel length of the indentor equal to the shell height was evaluated. The increase ratio of the energy is prominent when the hemispherical indentor is replaced by a flat-headed one in both shell shapes. Finite element simulation was also conducted. Deformation behaviors were successfully predicted when the kinematic hardening plasticity was introduced in the material model. Minoru Yamashita and Zubair Bin Khalil Copyright © 2015 Minoru Yamashita and Zubair Bin Khalil. All rights reserved. Generation Method of Multipiecewise Linear Chaotic Systems Based on the Heteroclinic Shil’nikov Theorem and Switching Control Sun, 28 Jun 2015 11:35:54 +0000 Based on the heteroclinic Shil’nikov theorem and switching control, a kind of multipiecewise linear chaotic system is constructed in this paper. Firstly, two fundamental linear systems are constructed via linearization of a chaotic system at its two equilibrium points. Secondly, a two-piecewise linear chaotic system which satisfies the Shil’nikov theorem is generated by constructing heteroclinic loop between equilibrium points of the two fundamental systems by switching control. Finally, another multipiecewise linear chaotic system that also satisfies the Shil’nikov theorem is obtained via alternate translation of the two fundamental linear systems and heteroclinic loop construction of adjacent equilibria for the multipiecewise linear system. Some basic dynamical characteristics, including divergence, Lyapunov exponents, and bifurcation diagrams of the constructed systems, are analyzed. Meanwhile, computer simulation and circuit design are used for the proposed chaotic systems, and they are demonstrated to be effective for the method of chaos anticontrol. Chunyan Han, Fang Yuan, and Xiaoyuan Wang Copyright © 2015 Chunyan Han et al. All rights reserved. Impact Analysis of Window-Wall Ratio on Heating and Cooling Energy Consumption of Residential Buildings in Hot Summer and Cold Winter Zone in China Thu, 21 May 2015 13:43:02 +0000 In order to assess the optimal window-wall ratio and the proper glazing type in different air conditioning system operation modes of residential buildings for each orientation in three typical cities in hot summer and cold winter zone: Chongqing, Shanghai, and Wuhan simulation models were built and analyzed using Designer’s Simulation Toolkit (DeST). The study analyzed the variation of annual heating energy demand, annual cooling energy demand, and the annual total energy consumption in different conditions, including different orientations, patterns of utilization of air conditioning system, window-wall ratio, and types of windows. The results show that the total energy consumption increased when the window-wall ratio is also increased. It appears more obvious when the window orientation is east or west. Furthermore, in terms of energy efficiency, low-emissivity (Low-E) glass performs better than hollow glass. From this study, it can be concluded that the influence and sensitivity of window-wall ratio on the total energy consumption are related to the operation mode of air conditioning system, the orientation of outside window, and the glazing types of window. The influence of the factors can be regarded as reference mode for the window-wall ratio when designing residential buildings. Qiaoxia Yang, Meng Liu, Chang Shu, Daniel Mmereki, Md. Uzzal Hossain, and Xiang Zhan Copyright © 2015 Qiaoxia Yang et al. All rights reserved. Numerical Study of the Influence of Heat Source on Stagnation Point Flow towards a Stretching Surface of a Jeffrey Nanoliquid Mon, 23 Mar 2015 12:51:25 +0000 An analysis is carried out to study the flow of Jeffrey fluid near a stagnation point towards a permeable stretching sheet. In particular, we investigate the effect of temperature dependent internal heat generation or absorption in the presence of nanoparticles. The governing system of partial differential equations is transformed into ordinary differential equations, which are then solved numerically using the fourth-fifth-order Runge-Kutta-Fehlberg method. Comparisons with previously published work on special cases of the problem are performed and found to be in excellent agreement. The results of the governing parametric study are shown graphically and the physical aspects of the problem are highlighted and discussed. G. K. Ramesh Copyright © 2015 G. K. Ramesh. All rights reserved. Study of RF Signal Attenuation of Human Heart Thu, 05 Mar 2015 13:38:04 +0000 A study of ultrawideband pulse propagation modeling through human body for all frequencies from 0.1 to 10.5 GHz is presented. Reflection coefficient and signal attenuation are computed from the model considering the variation of heart dimension with respect to time unlike a fixed dimension of heart used in earlier models. The performance of cardiac activity is studied from the change of signal attenuation. This estimation may help in the design of a noninvasive diagnostic system using ultrawideband of frequencies. Kedar Nath Sahu, Challa Dhanunjaya Naidu, M. Satyam, and K. Jaya Sankar Copyright © 2015 Kedar Nath Sahu et al. All rights reserved. Experimental Thermal Analysis of Diesel Engine Piston and Cylinder Wall Tue, 17 Feb 2015 12:47:17 +0000 Knowledge of piston and cylinder wall temperature is necessary to estimate the thermal stresses at different points; this gives an idea to the designer to take care of weaker cross section area. Along with that, this temperature also allows the calculation of heat losses through piston and cylinder wall. The proposed methodology has been successfully applied to a water-cooled four-stroke direct-injection diesel engine and it allows the estimation of the piston and cylinder wall temperature. The methodology described here combines numerical simulations based on FEM models and experimental procedures based on the use of thermocouples. Purposes of this investigation are to measure the distortion in the piston, temperature, and radial thermal stresses after thermal loading. To check the validity of the heat transfer model, measure the temperature through direct measurement using thermocouple wire at several points on the piston and cylinder wall. In order to prevent thermocouple wire entanglement, a suitable pathway was designed. Appropriate averaged thermal boundary conditions such as heat transfer coefficients were set on different surfaces for FE model. The study includes the effects of the thermal conductivity of the material of piston, piston rings, and combustion chamber wall. Results show variation of temperature, stresses, and deformation at various points on the piston. Subodh Kumar Sharma, P. K. Saini, and N. K. Samria Copyright © 2015 Subodh Kumar Sharma et al. All rights reserved. Modeling Breakthrough Curves of Citric Acid Adsorption onto Anionic Resins in an Aqueous Solution Wed, 11 Feb 2015 14:33:24 +0000 Breakthrough curves for citric acid adsorption from aqueous solution onto ion-exchange resin at 20, 35, and 55°C have been investigated. To predict breakthrough curves, three mathematical models have been analyzed based on the values of the least square method parameters, Durbin-Watson test, and mean relative percent error and, finally, appropriate models have been achieved. Models are in good agreement with experimental data based on the results. To examine models reliabilities and accuracy, models have been compared by various breakthrough curve data obtained by other investigators. The results show appropriate agreement and in some cases regression errors have been reduced to less than 1.0 percent. Sohrabali Ghorbanian, Mostafa Davoudinejad, Amir Khakpay, and Saeidreza Radpour Copyright © 2015 Sohrabali Ghorbanian et al. All rights reserved. Electrical Power Analysis Using the Scattering Bond Graph Mon, 09 Feb 2015 06:29:32 +0000 The perspective of the well known concept of active and reactive power in electrical systems is addressed in this paper. This concept is presented from the point of view of the bond graph methodology. The scattering matrix concept is used in order to deal with these formulations. The concept of active and reactive power is presented with some examples derived from single-phase AC circuits. The formulations and simulations of these circuits are presented. Roberto Tapia-Sánchez Copyright © 2015 Roberto Tapia-Sánchez. All rights reserved. Modeling of Sand and Crude Oil Flow in Horizontal Pipes during Crude Oil Transportation Wed, 21 Jan 2015 07:49:32 +0000 Some oil and gas reservoirs are often weakly consolidated making them liable to sand intrusion. During upstream petroleum production operations, crude oil and sand eroded from formation zones are often transported as a mixture through horizontal pipes up to the well heads and between well heads and flow stations. The sand transported through the pipes poses serious problems ranging from blockage, corrosion, abrasion, and reduction in pipe efficiency to loss of pipe integrity. A mathematical description of the transport process of crude oil and sand in a horizontal pipe is presented in this paper. The model used to obtain the mathematical description is the modified form of Doan et al. (1996 and 2000) models. Based on the necessity to introduce a sand deposit concentration term in the mass conservation equation, an additional equation for solid phase was derived. Difference formulae were generated having applied Fick’s equation for diffusion to the mass conservation equations since diffusion is one of the transport mechanisms. Mass and volume flow rates of oil were estimated. The new model, when tested with field data, gave 85% accuracy at the pipe inlet and 97% accuracy at the exit of the pipe. Samuel Eshorame Sanni, A. S. Olawale, and S. S. Adefila Copyright © 2015 Samuel Eshorame Sanni et al. All rights reserved. Two Chaotic Patterns of Dynamic Risk Definition for Solving Hazardous Materials Routing Problem Tue, 20 Jan 2015 06:27:01 +0000 In the case of determining routes for hazardous material transportation, risk is considered as a main attribute. Transport risk, which is usually combined with other attributes such as cost or travel time, plays a significant role in determining paths for hazardous materials transportation. Since, risk is chaotically affected by road incidents, decision makers are dealing with selecting a method for defining chaotic risk factors in hazmat transportation. In this paper, transport risk has been defined as a chaotic variable using two different methods of generating chaotic patterns. In an experimental road network, which consists of eighty-nine nodes and one hundred and one two-way links, two different methods of generating chaotic variables have been used for applying the proposed procedure. In addition, results for different amounts of risk and cost have also been analyzed in case study. Results revealed that different cost and risk priorities change the frequencies of selected paths determined for hazmat transportation, but the route convergence of the route to chaos method is better than that of the logistic map equation. Abbas Mahmoudabadi Copyright © 2015 Abbas Mahmoudabadi. All rights reserved. Investigations on Structural, Mechanical, and Dielectric Properties of PVDF/Ceramic Composites Tue, 06 Jan 2015 09:33:31 +0000 Polymer ceramic composites are widely used for embedded capacitor application. In the present work PVDF has been used as a matrix and CCTO and LaCCTO have been used as reinforcement. Extrusion process has been used for the synthesis of composites. X-ray diffraction (XRD) patterns confirm the formation of single phase CCTO, and LaCCTO in its pure as well as composite state. It is found that La doping in CCTO considerably increases the dielectric constant and reduces the dielectric loss. A similar trend is observed in the composites with the increasing content of CCTO and LaCCTO. Anshuman Srivastava, Karun Kumar Jana, Pralay Maiti, Devendra Kumar, and Om Parkash Copyright © 2015 Anshuman Srivastava et al. All rights reserved. Preoxidation and Activation of the Lignin Char: Carbonization and Oxidation Procedures Wed, 31 Dec 2014 00:10:40 +0000 A comprehensive process of pretreatment and oxidation of lignin char was developed to optimize the production of activated carbon. The lignin char was obtained by carbonization of lignin under nitrogen at 600°C for 2 hours. The optimum time and temperature used to oxidize the char without destruction were, respectively, 6 hours and 245°C. The oxygen improves the reactivity of the sample in CO2 and evolved the sample of a thermoplastic behaviour to a thermosetting behaviour. The oxygenation in air of the lignin char does not change the mode of deformation acquired by the material during the carbonization. The preoxidized coal reacts more than the nonoxidized coal during the CO2 activation, whereas the reduction in volume in the first case is smaller than in the second. The preoxidized and then activated carbon shows the formation and the development of microporosity at the expense of macroporosity. This microstructure is one of the main characteristics of activated carbon, which can be used as adsorbent for different pollutants. Saloua Sebbahi, Adnane Ahmido, Fatima Kifani-Sahban, Souad El Hajjaji, and André Zoulalian Copyright © 2014 Saloua Sebbahi et al. All rights reserved. Treatment Efficiency by means of a Nonthermal Plasma Combined with Heterogeneous Catalysis of Odoriferous Volatile Organic Compounds Emissions from the Thermal Drying of Landfill Leachates Sun, 28 Dec 2014 11:14:35 +0000 The objective of the present work was to assess the odoriferous volatile organic compounds depuration efficiency of an experimental nonthermal plasma coupled to a catalytic system used for odor abatement of real emissions from a leachate thermal drying plant installed in an urban solid waste landfill. VOC screening was performed by means of HRGC-MS analysis of samples taken at the inlet and at the outlet of the nonthermal plasma system. Odor concentration by means of dynamic olfactometry, total organic carbon, mercaptans, NH3, and H2S were also determined in order to assess the performance of the system throughout several days. Three plasma frequencies (100, 150, and 200 Hz) and two catalyst temperatures (150°C and 50°C) were also tested. Under conditions of maximum capacity of the treatment system, the results show VOC depuration efficiencies around 69%, with average depuration efficiencies between 44 and 95% depending on the chemical family of the substance. Compounds belonging to the following families have been detected in the samples: organic acids, alcohols, ketones, aldehydes, pyrazines, and reduced sulphur compounds, among others. Average total organic carbon removal efficiency was 88%, while NH3 and H2S removal efficiencies were 88% and 87%, respectively, and odor concentration abatement was 78%. Daniel Almarcha, Manuel Almarcha, Elena Jimenez-Coloma, Laura Vidal, Montserrat Puigcercós, and Iban Barrutiabengoa Copyright © 2014 Daniel Almarcha et al. All rights reserved. Modeling and Optimization for Production of Rice Husk Activated Carbon and Adsorption of Phenol Wed, 24 Dec 2014 07:18:40 +0000 Modeling of adsorption process establishes mathematical relationship between the interacting process variables and process optimization is important in determining the values of factors for which the response is at maximum. In this paper, response surface methodology was employed for the modeling and optimization of adsorption of phenol onto rice husk activated carbon. Among the action variables considered are activated carbon pretreatment temperature, adsorbent dosage, and initial concentration of phenol, while the response variables are removal efficiency and adsorption capacity. Regression analysis was used to analyze the models developed. The outcome of this research showed that 99.79% and 99.81% of the variations in removal efficiency and adsorption capacity, respectively, are attributed to the three process variables considered, that is, pretreatment temperature, adsorbent dosage, and initial phenol concentration. Therefore, the models can be used to predict the interaction of the process variables. Optimization tests showed that the optimum operating conditions for the adsorption process occurred at initial solute concentration of 40.61 mg/L, pretreatment temperature of 441.46°C, adsorbent dosage 4 g, adsorption capacity of 0.9595 mg/g, and removal efficiency of 97.16%. These optimum operating conditions were experimentally validated. Y. S. Mohammad, E. M. Shaibu-Imodagbe, S. B. Igboro, A. Giwa, and C. A. Okuofu Copyright © 2014 Y. S. Mohammad et al. All rights reserved. Adaptive Vibration Control of Piezoactuated Euler-Bernoulli Beams Using Infinite-Dimensional Lyapunov Method and High-Order Sliding-Mode Differentiation Mon, 22 Dec 2014 07:39:01 +0000 This paper presents an adaptive control scheme to suppress vibration of flexible beams using a collocated piezoelectric actuator-sensor configuration. A governing equation of the beams is modelled by a partial differential equation based on Euler-Bernoulli theory. Thus, the beams are infinite-dimensional systems. Whereas conventional control design techniques for infinite-dimensional systems make use of approximated finite-dimensional models, the present adaptive control law is derived based on the infinite-dimensional Lyapunov method, without using any approximated finite-dimension model. Thus, the stability of the control system is guaranteed for all vibration modes. The implementation of the control law requires a derivative of the sensor output for feedback. A high-order sliding mode differentiation technique is used to estimate the derivative. The technique features robust exact differentiation with finite-time convergence. Numerical simulation and experimental results illustrate the effectiveness of the controller. Teerawat Sangpet, Suwat Kuntanapreeda, and Rüdiger Schmidt Copyright © 2014 Teerawat Sangpet et al. All rights reserved.