Materials and Energy Research CenterInternational Journal of Engineering1025-249528920150901Catalytic Effect of Metal Species on Enhancement of CO2 Gasification Reactivity of Biomass Char1251125672573ENMaedeh MohammadiChemical Engineering, Babol Noshirvani University of TechnologyPOOYA LAHIJANISchool of Mechan, Universiti Sains MalaysiaJournal Article19700101In the Boudouard reaction, where CO2 is reacted with carbon (char) to produce CO, very high temperatures are required to shift the equilibrium towards CO production. This endothermic reaction is inherently slow and catalytic species are effective to speed up the reaction rate at temperatures below 900 °C. In this study, the catalytic effect of some alkali (K, Na), alkaline earth (Ca) and transition (Fe) metals on enhancing the CO2 gasification reactivity of pistachio shell (PS) char was investigated. The CO2 gasification studies were performed in a Thermogravimetric analyzer (TGA). Among the examined potassium species, K2CO3 showed the highest catalytic effect; wherein, complete carbon conversion was achieved 48.1% faster as compared to un-catalyzed PS char. The highest catalytic effect among the sodium salts was devoted to NaNO3 which showed 57.7% enhancement in the reactivity of char. CaCl2 and Fe(NO3)2 also showed the best catalytic performance among the examined calcium and iron species and improved the reaction rate by 64.6 and 46.1%, respectively.https://www.ije.ir/article_72573_26049a1fb8f70694715febeac45dea55.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249528920150901Two Important Issues Relevant to Torsional Response of Asymmetric 8-Story RC BuildingDesigned with Direct Displacement based Design Approach1257126772574ENEsmaeel Izadi ZamanabadiStructural Engineering Research Center, International Institute of Earthquake Engineering and SeismologyJournal Article19700101Direct displacement based design (DDBD) is a conceptual framework that directly design a structure to achieve an expected performance level under specified seismic intensity. In this study, two important issues relevant to torsional response of mass eccentric 8-story RC building designed with DDBD approach are investigated. These issues are including the effects of unbalanced mass distribution scenario on the torsional response parameters and the study of these parameters with reference to diagonal displacement. Diagonal displacement is the SRSS combination of the displacement demands along the direction of excitation and orthogonal direction. Three different unbalanced mass distribution scenarios which produce the same mass eccentricity were applied to the plan of the generic structural model to determine the general range of the mass moment of inertia (MMI) variation due to different unbalanced mass distribution scenarios. Expressions were established to correlate MMI and mass eccentricity in each scenario. Results show for slight eccentricities the variation of the MMI is negligible but as eccentricity is increased the range of the variation is extended. Then sensitivity analyses based on finite element method and inelastic time history analysis have been carried out on 8-story RC building frame designed with DDBD approach with different level of mass eccentricity and different MMI. Torsional response parameters in terms of maximum displacement demands of edge elements, maximum diaphragm rotation, maximum nominal relative displacement and maximum nominal rotation is compared with considering diagonal and horizontal displacement demands along seismic excitation.https://www.ije.ir/article_72574_2a0adce40afe3585a4d8ae1f05c07bb0.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249528920150901Elite Opposition-based Artificial Bee Colony Algorithm for Global Optimization1268127572575ENDongming JiangState Key Laboratory of Software Engineering, Wuhan UniversityXuezhi YueSchool of Science, JiangXi University of Science and TechnologyKangshun LiSchool of Information, South China Agricultural UniversityShenwen WangSchool of Information Engineering, Shijiazhuang University of EconomicsZhaolu GuoSchool of Science, JiangXi University of Science and TechnologyJournal Article19700101 Numerous problems in engineering and science can be converted into optimization problems. Artificial bee colony (ABC) algorithm is a newly developed stochastic optimization algorithm and has been widely used in many areas. However, due to the stochastic characteristics of its solution search equation, the traditional ABC algorithm often suffers from poor exploitation. Aiming at this weakness of the traditional ABC algorithm, in this paper, we propose an enhanced ABC algorithm with elite opposition-based learning strategy (EOABC). In the proposed EOABC, it executes the elite opposition-based learning strategy with a preset learning probability to enhance its exploitation capacity. In the numerical experiments, EOABC is tested on a set of numerical benchmark test functions, and is compared with some other ABCs. The comparisons confirm that EOABC can achieve competitive results on the majority of the benchmark test functions.https://www.ije.ir/article_72575_70e4a524d6423207b10211c27c8c6ea8.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249528920150901A Comparative Study of VHDL Implementation of FT-2D-cGA and FT-3D-cGA on Different Benchmarks (RESEARCH NOTE)1276128572576ENYasser Baleghi DamavandiDept. of Electrical and Computer Engineering, Babol Noshirvani University of Technology0000-0002-2882-4613Peyman AshoorianComputer & Electrical engineering, Babol Noshirvani university of technologyJournal Article19700101This paper presents the VHDL implementation of fault tolerant cellular genetic algorithm. The goal of paper is to harden the hardware implementation of the cGA against single error upset (SEU), when affecting the fitness registers in the target hardware. The proposed approach, consists of two phases; Error monitoring and error recovery. Using innovative connectivity between processing elements and efficient correction policy, the PEs will prohibit spreading the faulty evaluated individual in the population. In the experiments, three metrics and four test functions are used to show the performance of the proposed structures. Two structures (2D and 3D) of proposed FT-cGAs are set to optimize various test functions. The experimental results illustrate the robustness of the proposed system. An outstanding outcome was that the implemented fault tolerant algorithm was able to reach the optimal solution when at least one processing element is healthy in population.https://www.ije.ir/article_72576_4b4bf7310183f9afda3e4320df617859.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249528920150901Implementation of Floating Output Interleaved Input DC-DC Boost Converter1286129472577ENN.SENTHIL KUMARSchool of Electrical and Electronics Engg, VIT Uninversity, Chennai0000-0002-6454-0749Journal Article19700101This paper presents the analysin ,design and implementation of a high voltage ratio topology of DC-DC converter. The DC-DC converter has high voltage ratio with reduced input current, output voltage and output current ripple, and also reduces the voltage and current rating of power electronics components and compared with conventional boost converter. The voltage stress on the switches are reduced in this topology. Analysis, design and converter operating waveforms in the continuous conduction mode are provided along with design guidelines. The converter has been designed for rated power of 50W, input voltage of 24V, output voltage of 72V and switching frequency of 25 kHz. The floating output interleaved input high voltage gain converter is compared with conventional boost converter, hardware and simulation results are verified.https://www.ije.ir/article_72577_bc40e3192775193e248cdd6888208e32.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249528920150901Economic Order Quantity for Deteriorating Items with Non Decreasing Demand and Shortages Under Inflation and Time Discounting1295130272578ENRAKESH TRIPATHIMathematics, Graphic Era University, DehradunJournal Article19700101Some products like green vegetables, volatile liquids and others deteriorate continuously due to evaporation, spoilage etc. In this study, an inventory model is developed for deteriorating items with linearly time dependent demand rate under inflation and time discounting over a finite planning horizon. Shortages are allowed and linearly time dependent. Mathematical model is presented for the proposed model. We show that total profit is concave with respect fraction of scheduling period k. The results are discussed with the help of numerical example. A sensitivity analysis of the optimal solution with respect to the key parameters is also discussed.https://www.ije.ir/article_72578_3417f9edc1e099c5d2d414b3b940c1fc.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249528920150901Group Decision Making based on a New Evaluation Method and Hesitant Fuzzy Setting with an Application to an Energy Planning Problem1303131172579ENReza Tavakkoli-MoghaddamIndustrial Engineering, University of Tehran0000-0002-6757-926XM. MousaviDepartment of Energy Economics, Economics Faculty, University of TehranJournal Article19700101In recent two decades, countries focused on minimum extraction of fossil fuels and utilized the renewable energies based on countries' policies and the environmental considerations. Thus, choosing the best renewable energy alternative is a significant role to investment on them. Among the classical decision approaches that have used in the literature, the hesitant fuzzy sets (HFSs) theory is appropriate tool to deal with uncertain and imprecise condition. The HFSs could help experts or decision makers in energy sector to consider some membership degrees for a renewable energy alternative regarding to conflicted criteria under a set. The aim of this paper is to propose a hierarchical complex proportional assessment (COPRAS) method to consider subjective judgments and objective opinions based on HFS theory for multi-criteria group decision making (MCGDM) problems. In addition, the hesitant fuzzy decision matrix as well as sub-criteria and main criteria are defined based on linguistic variables and then converted to hesitant fuzzy elements. In the proposed approach, weights of experts are different and computed by proposed hesitant fuzzy entropy method. Also, weights of main criteria are determined by a new relation in n level of hierarchy structure with experts' risk preferences. Finally, a real case study in Iran about the renewable energy selection in hierarchy structure is presented and hesitant fuzzy hierarchical complex proportional assessment (HF-HCOPRAS) method is applied to show the efficiency and practically of the proposed approach.https://www.ije.ir/article_72579_b326d75e8592ef730c689e640072aaf4.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249528920150901Evaluating Construction Projects by a New Group Decision-Making Model Based on Intuitionistic Fuzzy Logic Concepts1312131972580ENH. GitinavardSchool of Industrial Engineering , Iran University of Science and TechnologyS.M. MousaviIndustrial Engineering Department, Faculty of Engineering, Shahed UniversityJournal Article19700101Select an appropriate project is a main key for contractors to increase their profits. In practice, in this area the uncertainty and imprecise of the involved parameters is so high. Therefore, considering fuzzy sets theory to deal with uncertainly is more appreciate. The aim of this paper is present a multi-criteria group decision-making model under an intuitionistic fuzzy set environment. Hence, the weight of each decision maker and each criterion are considered different. Indeed, decision makers\' weights are determined based on a novel intuitionistic fuzzy index, and criteria’ weights are specified by proposed method according to the concept of closer to ideal solution and farther from negative ideal solution. Then, the potential projects are ranked based on new intuitionistic fuzzy relative closeness coefficient. Thus, the proposed intuitionistic fuzzy group decision-making model is applied in an illustrative example about construction project selection from the recent literature. Finally, the ranking results are compared with a fuzzy TOPSIS method to indicate the applicability and efficiency of the proposed model.https://www.ije.ir/article_72580_ab02382917baff6e02cde863e30cff63.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249528920150901A Novel, Simple and Cost Effective Al A356/Al2O3 Nano-composite Manufacturing Route with Uniform Distribution of Nanoparticles1320132772581ENNasrin SasaniDepartment of Materials and Metallurgical Engineer, Ferdowsi University of MashhadMahin Houshyar SadeghianDepartment of Materials and Metallurgical Engineer, Ferdowsi University of MashhadHeydar KhadiviMaterials Research Group, Iranian Academic Center for Education, Culture and Research (ACECR),Masoud Golestanipour, ACECRJournal Article19700101The present study aims at developing A356/Al2O3(np) nano-composite with a novel and cost effective method for attaining homogeneous dispersion of Al2O3 nanoparticles in the Al matrix. In the current research, Al micro powders distributed on aluminum foil and then Al2O3 nanoparticles ultra-sounded in ethanol and sprayed on Al substrate. Subsequently, the sandwich foil was added to molten A356 during stirring. The nano-composite was characterized through scanning electron microscopy (SEM) for microstructural evaluations. Also, mechanical properties of A356/Al2O3(np) nano-composite was measured through compression and hardness tests. By this novel method an Al based (A356) nano-composite with 2 wt. % Al2O3 nanoparticles was obtained which shows 26.79%, 95.6 % and 43 % enhancement in yield stress, compression strength and hardness, respectively, as compared with the pure alloy processed under the same condition.https://www.ije.ir/article_72581_e338c8fbbd3db2dfa97ccae6f84875ba.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249528920150901Effect of Mo Addition on Nanostructured Ni50Al50 Intermetallic Compound Synthesized by Mechanical Alloying1328133572582ENGholamhosein Akbarimetallorgy, shahid bahonar kermanAli KhajesarviMaterials Science and Engineering, shahid bahonar kermanJournal Article19700101The mechanical alloying process was used to synthesize the Ni50Al50−xMox nanocrystalline intermetallic compound using pure Ni and Al elemental powder. This process was carried out in the presence of various Mo contents as a micro-alloying element for various milling times. Structural changes of powder particles during mechanical alloying were studied by X-ray diffractometry (XRD) and scanning electron microscopy (SEM). Results showed that mechanical alloying in various combinations was completed after 48 h of milling time. Minimum crystallite size of the as-milled powders (∼10 nm) was achieved after introducing Mo and milling for 128 h. Also, lattice strain decreased with increasing milling time up to 48 h and again increased after 48 h of milling time. On the other hand, the presence of Mo significantly affected variation intensity of the lattice parameter and morphology of the powder particles.https://www.ije.ir/article_72582_4a208957356094d91ad2b52e905e1fcd.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249528920150901Cluster Analysis of Acoustic Emission Signals for Carbon/Epoxy Composite in Four-point Bending Test (RESEARCH NOTE)1336134272583ENOmid PedramMechanical Engineering, University of ZanjanJournal Article19700101Due to the extensive use of composites in various industries and the fact that defects reduce ultimate strength and efficiency during operation, detection of failures in composite parts is very important. The aim of this paper is to use Acoustic Emission (AE) non-destructive method in four-point bending test of carbon/epoxy composite to analyze and examine the failure mechanisms. This method is based on waves that activated from defects in structures which are built during loading. Sensors collected acoustic signals which created by the separated layers. Each stage of failure is in specific frequency range and explains a specific mechanism. Clustering of these signals is done with C-mean and K-mean algorithm and compared with the results of previous works. The failure process was shown to proceed through the four stages. In both algorithms, each cluster has coincidence with one part of these stages.https://www.ije.ir/article_72583_1e0cde851aa374091159585ab8b826f8.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249528920150901Numerical Study of Electro-thermo-convection in a Differentially Heated Cavity Filled with a Dielectric Liquid Subjected to Partial Unipolar Injection1343135072584ENPhilippe TraoreDépartement Fluide-Thermique-Combustion, Institut PPRIMEHabib Ben Aissiaenergy department, National Engineering School of MonastirNaceur BorjiniDepartment of Energy, National Engineering School of MonastirWalid HassenDepartment of Energy, National Engineering School of MonastirJournal Article19700101The Coulomb force applied by an electric field on any charge present in a dielectric liquid may cause fluid motion. At high applied electric fields in an insulating liquid, electric charge carriers are created at metallic/liquid interfaces, a process referred to as ion injection, and result from electrochemical reactions. In this article we deals with the problem of electro thermal convection in a dielectric liquid placed in a square cavity and subjected to the simultaneous action of a thermal gradient and an electric field. Thus the aim is to analyze, from a numerical point of view, the evolution of flow structure, charge distribution and heat transfer for the case of a strong injection. The studied configuration is the following: the vertical walls were differentially heated; the horizontal walls adiabatic and only part of the bottom wall (33% of the total length) contributes to the charge injection. Three possible configurations are treated depending on the position of the injection zone: so we identify an injection from the left, the middle and finally the right.https://www.ije.ir/article_72584_b3cc7ec6f803635def52177ca0042fe1.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249528920150901Dynamic Analysis of a Rotor Supported on Ball Bearings with Waviness and Centralizing Springs and Squeeze Film Dampers1351135872585ENSina ModaresahmadiDepartment of Mechanical Engineering, Tarbiat Modarres University, Tehran, IranMohammadreza GhazaviDepartment of Mechanical Engineering, Tarbiat Modarres University, Tehran, IranMandana Sheikhzad SaravaniDepartment of Mechanical Engineering, University of Wollongong,Wollongong,AustraliaJournal Article19700101Squeeze film dampers (SFDs) are often used in machines with high rotational speed to reduce non-periodic behavior by creating external damping. There are some structural parameters which are of great importance in designing these systems, such as oil film thickness and inner race mass of SFD. Moreover, there is a crucial parameter associated with manufacturing process, under the title of waviness. Geometric imperfections are often called waviness if its wavelength is much longer than Hertzian contact width. In this paper, a system of a flexible rotor and two ball bearings with squeeze film dampers and centralizing springs and also consideration of waviness has been modeled and solved by a numerical integration method to investigate the system dynamic response. Results show that by increasing the number of wave lobes, non-periodic and chaotic behavior increases. This reveals the importance of manufacturing accuracy and necessity of taking this term into account in simulations. Moreover, by changing the oil film thickness, it is revealed that there is an optimal value for this parameter to provide maximum damping. In addition, with increasing the inner race mass of SFD, the disc displacement amplitude increases. This reveals the importance of utilizing light materials in manufacturing the SFDs.https://www.ije.ir/article_72585_a309b8f4331dfe947ddea0fc233ff3b4.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249528920150901Optimal Design of Magnetorheological Fluid Damper Based on Response Surface Method1359136772586ENHamed SafarzadehDepartment of Mechanics, Ferdowsi University of Mashhad, Mashhad, IranMohammad Hossian DjavareshkianDepartment of Mechanics, Ferdowsi University of Mashhad, Mashhad, IranAli EsmaeiliEngineering Faculty, Ferdowsi University of Mashhad, Mashhad, IranJournal Article19700101In this research, the effect of shape parameters such as number of magnet wire turns, spools, thickness of the gap, and pole length in a Magneto-rheological (MR) fluid damper is analytically investigated and the optimization of these parameters is done with response surface method (RSM) which is combined Neuro-Fuzzy method and Particle Swarm Optimization (PSO) algorithm. Since the electro-magnetic and mechanical components of a Magneto-rheological (MR) fluid damper have a direct effect on the electrical power consumption, time delay and damped force, which are considered as objective functions. Because of the nonlinear behavior of the components, a robust approach is needed to predict their behaviors; therefore, Neuro-Fuzzy is utilizeded to generate a high accurate surface and PSO finds the optimum solution base on the surface. The sensitive analysis is also performed to examine the variation of the objective functions with various input parameters. In this process, the best parameters are obtained by overtaking the appropriate value of the objective functions. The results demonstrate that the optimum MR damper has provided the best configurations so that damps a maximum force in a minimum time and lowest power consumption. On the other hand, the amplitude of vibrations is significantly decreased in the presence of the optimized MR damper.https://www.ije.ir/article_72586_c407ec4a894ee00a2e969ef3cb0cb522.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249528920150901Stress Variations Effect on the Accuracy of Slitting Method for Measuring Residual Stresses1368137472587ENK. BehnamMechanical Engineering, Bu-Ali Sina UniversityS. HeydarianMechanical Engineering, Bu-Ali Sina UniversityA.H. MahmoudiMechanical Engineering, Bu-Ali Sina UniversityJournal Article19700101To maintain the structural integrity of the engineering components, having an exact knowledge of residual stresses is important. Among all mechanical strain relief techniques to measure residual stresses, slitting is one of the youngest. This technique relies on the introduction of a narrow slot of increasing depth in a part containing residual stresses. Similar to other measurement techniques, slitting also employs simplifying assumptions. One of these assumptions is that the stress does not vary along the cut line. There are many sources of errors in the slitting method. However, the error caused by this assumption can be severe. In this research, residual stresses of quenched samples were measured experimentally using slitting technique. The results were then compared with those obtained from the finite element analyses. The cylindrical specimens were designed with different ratio of height to diameter to investigate the effect of stress variations in transverse direction along the cut plane. It was evident that the non-uniformity of stress can severely influence the residual stresses measurement. The experimental results confirmed the numerical findings.https://www.ije.ir/article_72587_0ca9ed1b645466fb22c7146b4780b15a.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249528920150901Reverse Engineering for Designing the Coupling of a 32 MW Rotor-generator by Shrink Fitting Method (TECHNICAL NOTE)1375138272588ENMohammad Reza Mohammadi ArhaniEsmaeil PoursaeidiDepartment of Mechanical Engineering, University of Zanjan, Zanjan, IranJournal Article19700101This study presents a designing process for refurbishing of a 32 MW rotor-generator damaged coupling. The reason of rotor damage was being hit by the quivers of an explosion. The original coupling was union with the rotor formed after a machining process on a mono block forged rotor. In some areas imposed damages caused the breaking off and detachment of some parts in the coupling flange. Because of this accident, the coupling region was removed by machining completely and another coupling was made and mounted on the rotor-generator shaft by shrink fitting. Reverse engineering method was used with comparing a 145 MW rotor-generator. At first all of the mechanical loadings on the coupling were assessed. The calculations include analytical method by using ANSI standard and simulation of ANSYS software. The results showed that in spite of geometrical restrictions, it is possible to install a distinct coupling by shrink fitting on the rotor generator shafthttps://www.ije.ir/article_72588_d5044908a60a36552f8aa59a692a11ec.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249528920150901Investigation on Tensile Strength of Friction Stir Welded Joints in PP/EPDM/Clay Nanocomposites1382139172589ENMohammadreza NakhaeiMechanical Engineering, tabriz universityNasrollah Bani Mostafa ArabMechanical Engineering, Shahid Rajaee Teacher Training UniversityGholam RezaeiMechanical Engineering, Shahid Rajaee Teacher Training UniversityJournal Article19700101Polymer-based nanocomposites due to their advantages such as corrosion resistance,adequate mechanical properties and low cost are widely used in modern technologies. The increasing application of these nanocomposites, and hence their welding seems unavoidable. In this paper, a novel hottool in friction stir welding process is used for butt welding nanocomposite plates of 5 mm thick containing polypropylene , ethylene-propylene diene monomerand Cloisite 15A. Response surface method is used to design experiments and determine the effect of process parameters such as tool rotational speed, welding speed, tool shoulder temperature and clay content on weld tensile strength. The results show that although increasing clay content in the base material increases its tensile strength but decreases the weld tensile strength; such that in the specimens with 0, 3 and 6% clay content, the weld tensile strength equals to 94, 80 and 61 percent of the respective base materials.https://www.ije.ir/article_72589_b968357ae4b6ff7b4564f96eb753766d.pdfMaterials and Energy Research CenterInternational Journal of Engineering1025-249528920150901Improving Performance of Mining Equipment Through Enhancement of Speed Factor: A Case Study (Research Note)1392140072590ENMousa MohammadiDepartment of Minig Engineering, Indian Institute of Technology (BHU)Piysh RaiDepartment of Minig Engineering, Indian Institute of Technology (BHU)Journal Article19700101Loading and hauling machineries are highly capital intensive equipment to procure, operate and maintain in surface mining operation. It must be borne in mind that with this huge and capital-intensive equipment, every second of its life time is absolutely important from the production and productivity point of view. As such, it is imperative to optimize the overall cycle time and speed factor of this equipment in order to reap the benefits of this equipment to the fullest extent. Speed factor is the ratio of the planned cycle time of the equipment to the actual cycle time. In this light, the present paper is an endeavour to compute speed factor and critically analyze cycle time segments of dragline operation in one of the major opencast projects in India.https://www.ije.ir/article_72590_7fafd7d7cabc8285967ff6583d2c1bdf.pdf