فهرست مطالب

  • Volume:31 Issue: 8, 2018
  • تاریخ انتشار: 1397/05/30
  • تعداد عناوین: 18
  • S. Abbaspour, S. K. Sadrnezhaad Pages 1159-1165
    Arrayed Ti6Al4V nanotubes (TNT) coated with hydroxyapatite (HA) were synthesized via electrochemical anodization method. Paracetamol was loaded onto TNT-HA electrode. Effects of anodization, nanotube formation and hydroxyapatite deposition on sorption and release of the drug were investigated. Saturation time of paracetamol on the anodized samples was 30% shorter than the hydroxyapatite-coated samples. Release behavior of the loaded drug was studied by (a) plunging the probe into phosphate buffered saline (PBS), (b) sampling the drug-loaded PBS at different times and (c) analyzing the solution via ultraviolet-visible (UV-vis) spectroscopy. Results showed that HA electrodes hold higher amounts of paracetamol than the anodized samples at longer times. Scanning electron microscopy (SEM), MTT assay, and nanoindentation tests were used to characterize the produced electrodes.
    Keywords: Titanium nanotubes, Drug capacity, Drug release, Hydroxyapatite, Paracetamol
  • M. Afarin, I. Alemzadeh, Z. Kouchak Yazdi Pages 1166-1171
    Conjugated linoleic acid (CLA) is one of the most physiological active fatty acids due to its positive effect on prevention of diseases such as obesity, hyperlipidemia, atherosclerosis and cancer. The aim of this study was to optimize the production of conjugated linoleic acid (CLA)% in alkali isomerization of safflower oil including 71% linoleic acid (LA) using response surface methodology (RSM). The effect of three reaction variables such as temperature, reaction time and amount of KOH on CLA production was investigated using design-expert software. The optimal condition determined at this point, 72% total CLA with the yield of 84% temperature reaction time and the amount of KOH were 187.6 ºC, 2.12 h 48.7 g; respectively. Further results indicate that just two reaction parameters including temperature and the amount of catalyst have significant effects on CLA production %; however,the reaction time showed negligible impact on CLA production.
    Keywords: Conjugated linoleic acid, safflower oil, RSM, optimization
  • M. H. Alhassani, S. M. Al-Jubouri, W. O. Noori, H. A. Al-Jendeel Pages 1172-1179
    This work deals with kinetics and chemical equilibrium studies of esterification reaction of ethanol with acetic acid. The esterification reaction was catalyzed by an acidic ion exchange resin (Amberlyst-15) using a batch stirred tank reactor. The pseudo-homogenous and Eley-Rideal models were successfully fitted with experimental data. At first, Eley-Rideal model was examined for heterogeneous esterification of acetic acid and ethanol. The pseudo-homogenous model was investigated with a power-law model. The apparent reaction order was determined to be (0.88) for Ethanol and (0.92) for acetic acid with a correlation coefficient (R2) of 0.981 and 0.988, respectively. The reaction order was determined to be 4.1087x10-3 L0.8/(mol0.8.min) with R2 of 0.954. The adsorption constants of acetic acid and ethanol were calculated as 0.023 and 0.044 L/mol, respectively and the lumped reaction constant were determined to be 5*10-4 L2/gcat.mol.min. The results of the reaction kinetic study show that the high acetic acid/ethanol molar ratio was favored. The maximum conversion of 70 % was obtained at 70°C for acetic acid/ethanol molar ratio of 4.
    Keywords: Kinetics, Amberlyst, 15, Pseudo, homogeneous model, Eley, Rideal model
  • W. Haryanto, A. Prasetio, A. Mulyo, Z. Zakaria Pages 1180-1186
    Batubesi Dam which is located in Sorowako region in the middle part of Sulawesi island had been designed with seismic coefficient about 0.20g. The region constitutes an active earthquake zone with the recurrence frequency and magnitude of the earthquake are relatively high. The region is located on and active fault zone due to lateral fault movement (strike-slip) of Matano fault, Palukoro fault, and Walanea fault that categorized as shallow crustal earthquakes. To recognize characteristic of the earthquake at the site of interest, the historical earthquakes (background) data surrounding the study area and local microtremor measurements data are analyzed by means of a probabilistic seismic hazard analysis (PSHA) and deterministic seismic hazard analysis (DSHA) using some ground-motion models in attenuation relationship equations in resulting of seismic hazard parameter as represented by peak ground acceleration (PGA) values in earthquake scenario at operating basis earthquake (OBE), maximum design earthquake (MDE), and maximum credible earthquake (MCE) conditions. The PGA value in OBE condition is about 0.35g, in MDE about 0.45g, and in MCE about 0.49g. These values are used as reference to evaluate compliance of the current technical aspects with the new required design facing the updated seismicity parameters.
    Keywords: seismicity, seismic hazard analysis (SHA), peak ground acceleration (PGA), operating basis earthquake (OBE), maximum design earthquake (MDE), maximum credible earthquake (MCE)
  • M. Rahmannejad, V. Toufigh Pages 1187-1195
    Improvement and stabilization of soils are widely used to improve the physical and mechanical properties of sandy soils. Despite the abundance of researchers that have been conducted on this topic to date, most of them have focused on dry soil. The effects of the existing water in the soil and different curing durations (curing environment) have not been investigated. In this study, different percentages of epoxy resin and sand with different level of water content were studied. In this paper, a series of unconfined compressive strength (UCS) tests were conducted on mixtures of sand-resins using different percentages of resins at different water content levels. In addition, these specimens were cured under different moisture conditions, and the effect of moisture on specimens was evaluated over time. The results of this study showed that the addition of epoxy resin to sandy soil significantly increased its UCS which highly depended on epoxy resin percentage, water content and curing time. As the concentration of epoxy resin and the curing time increased, the strength increased; however, epoxy resin was more effective. On the other hand, increasing the water content had a negative effect on their strength of the specimens. According to this study, the epoxy resin could be selected to be appropriate and beneficial as a stabilizer for sandy soil due to its relatively high compressive strength and high resistance to aggressive environment.
    Keywords: Epoxy resin, Sandy soil, Unconfined compressive strength, Water content, Curing time
  • H. Sarkheil, Y. Azimi, S. Rahbari Pages 1196-1204
    Utilization of water in different parts of industrial life cycles brings a huge concern on environmental water and wastewater pollutions. In this research, environmental quality assessment of wastewater is studied using fuzzy logic. Fuzzy appliance is due to existance of statistical considerations (including standard deviations), various uncertainties, non-linearity and complexity of functions. A Mamdani fuzzy inference system (FIS) is developed for prediction of a fuzzy wastewater quality index (FWWQI) where four variables of Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Suspended Solids (TSS) and pH are considered. To assess the performance of the proposed index under actual conditions, water quality data of refineries at South Pars Special Economic and Energy Zone, Iran, are employed in the time interval from 2011 to 2014. Findings of this research indicated that only BOD and COD were the dominant pollutants for about 66% and 34% of analyzed time, respectively, which exceeds the standards. Moreover, the time pattern for the output indices represents that FWWQI varied from "Moderate" in 2011 to "Good" in 2014. In addition, comparison of the FWWQI results with two conventional classic methodologies indicated that the proposed fuzzy method well covers the two classic methodologies. Finally, it is noticed that all three proposed WQIs exhibit correspondingly "Good" level in the year 2014. Thus, the time pattern for the parameters and indices express continual improvement as outcome of ISO 14001 and HSE-MS.
    Keywords: Water Quality Index WQI, Wastewater, Fuzzy inference, Water Pollutants
  • H. Ghasemzadeh, M. Ghasemzadeh, A. M. Zare Bidoki Pages 1205-1214
    Search engines are still the most important gates for information search in internet. In this regard, providing the best response in the shortest time possible to the user's request is still desired. Normally, search engines are designed for adults and few policies have been employed considering teen users. Teen users are more biased in clicking the results list than are adult users. This leads to fewer clicks on the lowly-ranked search results. Such behavior reduces teen users’ navigation and result extraction skills. With an increase in information load and in teen’s demands, lack of efficient methods leads to inefficiency of search engines regarding teen users. For the purpose, this study discovers teen users’ search behavior and its application in yielding an improved search is strongly recommended. In this way, the pattern of teen users’ popular clicks is identified from a large search log through mining of users’ search transactions based on the frequency and similarity of the clicks in the search log. Then, using binary classification, the closest query into the teen user’s desired one is identified. To discover teen users’ behavior, we took advantage of the AOL query log. System efficiency was examined on the AOL query search log. Results reveal that click pattern improves approaching the query to the one desired by teen users. Generally, this study can demonstrate that in data recovery, application of click behavior and its binary classification can result in improved access of teen users to their desired results.
    Keywords: Search engine, Query log, Search behavior, Teen user, Query recommendation
  • O. Rivera, M. Mauledoux, A. Valencia, R. Jimenez, O. Aviles Pages 1215-1221
    In this paper, a hardware in the loop simulation (HIL) is presented. This application is purposed as the first step before a real implementation of a Generalized Predictive Control (GPC) on a micro-grid system located at the Military University Campus in Cajica, Colombia. The designed GPC, looks for keep the battery bank State of Charge (SOC) over the 70% and under the 90%, what ensures the best performance in the battery bank according its technical specifications. The GPC algorithm was embedded on a STM32 microcontroller and the micro-grid model was embedded on an ARDUINO MEGA microcontroller.
    Keywords: Generalized Predictive Control, Hardware in the Loop, Micro, grid, STM32
  • M. Boussaada, R. Abdelaati, H. Yahia Pages 1222-1227
    This paper provides experimental and simulation tools to characterize a Photo-Voltaic (PV) panel. To achieve this objective, we start from a PV electrical model and we propose a circuit using Diode-based-equivalent PV (DBEPV) panel. This circuit is presented as a prototype of an equivalent PV panel. It is designed to emulate a real PV module in different climatic conditions (irradiance and temperature). In addition, a new characterization tool for the PV panel, based on the automatic progression of the duty cycle of a Pulse-Width-Modulation (PWM) signal driving DC/DC buck converter, is developed. This characterization tool can emulate a variable resistance from a zero value to the highest one. An ISIS software package and a MATLAB®/Simulink® environment are used to simulate the characterization of a real PV panel, and the proposed prototype is experimentally validated. The experimental results were obtained and compared with those extracted from simulation. An identification of the parameters of the nonlinear mathematical model of the PV panel is necessary to validate our new approach characterization of a real PV panel and a prototype DBEPV one. A parametric characterization method based on iterative algorithm is applied. A good agreement was achieved. Indeed, our comparison showed the efficiency and feasibility of DBEPV prototype and our characterization method.
    Keywords: DC, DC buck converter, New characterization tool, PCM Identification, PV panel
  • M. Arehpanahi, D. Paknia Pages 1228-1233
    In this paper a new 5-level single phase symmetrical cascade multi-level inverter is proposed. The proposed topology contains combination of unidirectional and bidirectional power switches based on output voltage level number. The number of power switches and withstanding voltage of powers witches were reduced related to the other topologies. This configuration can be extended to the n-level inverter. In symmetrical case of proposed inverter the 5th harmonic output voltage will be eliminated. The performance analysis of the proposed inverter using suitable switching algorithm for producing the 5-level output voltage was confirmed by simulation and experimental results.
    Keywords: cascade inverter, multi, level, harmonic distortion, bidirectional switches, unidirectional switches, harmonic elimination
  • A. Mohammadi, H. Hamidi Pages 1234-1239
    Online Social Networks (OSN) becomes the largest infrastructure for social interactions like: making relationship, sharing personal experiences and service delivery. Nowadays social networks have been widely welcomed by people. Most of the researches about managing privacy protection within social networks sites (SNS), observes users as owner of their information. However, individuals cannot control their privacy and it’s been controlled by groups. Using OSNs is making concerns about privacy related to online personal data. According to number of studies, till now so many efforts has been done to protect confidentiality and security of data on social networks, but it seems that understanding the concept of privacy protection is too essential for people. The purpose of this article is to analyze tools and algorithms that proceed concerns about privacy protection and data security situation in social networks among adults, adolescents and children. These statistical tools and algorithms, analyze collected data. The results of this literature review showed that most distribution of these articles in this case are related to 2014. Furthermore, survey method was most current of collecting information in these researches.
    Keywords: Online Social Networks (OSN), Security Concerns, Protection Behavior. Information Disclosure
  • R. Davoudi, F. Dehghanian, M. A. Pirayesh Pages 1240-1249
    In this paper an emergency service vehicle (ESV) location problem has been considered in which it is assumed that each emergency call may require more than one ESV. In ESV location problem two factors should be known; the location of stations and the number of ESVs at each station. Hence, a nonlinear mixed integer programming model is presented in order to maximize the total response rate to the emergency calls. Moreover, a solution method based on genetic algorithm is provided and efficiency of the algorithm is evaluated with regard to the results from an exhaustive enumeration method. The model is applied to the real case study based on the data from Mashhad city to find the emergency gas stations and the required ESVs. Finally, a sensitivity analysis on the main parameters of the model is conducted and the managerial insights were reported. The results indicate that considering the fact that each call may require more than one ESV is very influential on the response rate and the assumption of each call requires just one ESV makes the results unrealistic.
    Keywords: Emergency service vehicle, facility location, Genetic algorithm, Emergency gas station
  • M. Fadaei, R. Tavakkoli-Moghadam, A. A. Taleizadeh, D. Mohammaditabar Pages 1250-1257
    Solution concepts in cooperative games are based on either cost games or benefit games. Although cost games and benefit games are strategically equivalent, that is not the case in general for solution concepts. Motivated by this important observation, a new property called invariance property with respect to benefit/cost allocation is introduced in this paper. Since such a property can be regarded as a fairness criterion in cooperative games when deciding on choosing the solution concepts in coordination contracts, it is crucially important for players to check if the solution concepts available in contract menu possesses this property. To this end, we showed that some solution concepts such as the Shapley value, and the -value satisfy invariance property with respect to benefit/cost allocation but some others such as Equal Cost Saving Method (ECSM) and Master Problem variant I ( ), do not. Furthermore, a measure for fairness with respect to equitable payoffs and utility is defined and related to invariance property. To validate the proposed approach, a numerical example extracted from the existing literature in benefit/cost cooperative games is solved and analyzed. The results of this research can be generalized for all solution concepts in cooperative games and is applicable for n-person games.
    Keywords: Game theory, Cooperative games, Coordination contract, Solution concepts, Shapley value, Fairness
  • H. Mohammadzadeh, N. Sahebjamnia, A. M. Fathollahi-Fard, M. Hahiaghaei-Keshteli Pages 1258-1266
    Nowadays, cross-docking is one of the main concepts in supply chain management in which products received to a distribution center by inbound trucks which are directly to lead into outbound trucks with a minimum handling and storage costs as the main cost of a cross-docking system. According to the literature, several metaheuristics and heuristics are attempted to solve this optimization model. In this regard, this study utilizes three recent nature-inspired metaheuristics among the first studies in this area. Red Deer Algorithm (RDA), Virus Colony Search (VCS) and Water Wave Optimization (WWO) are three novel nature-inspired algorithms proposed recently to employ their applications in engineering problems. The used algorithm’s parameters were selected by Taguchi method to enhance the efficiency of algorithms. The outputs of the proposed algorithms are assessed with each other in different criteria along with statistical analyses and the results yielded by prior works. The results demonstrate that RDA showed a competitive performance compared with mixed other existing algorithms.
    Keywords: cross, docking, truck scheduling, red deer algorithm, virus colony search, water wave optimization
  • A. Mohammadi, H. Hamidi Pages 1267-1273
    The purpose of this research, is to study factors influencing privacy concerns about data security and protection on social network sites and its’ influence on self-disclosure. 100 articles about privacy protection, data security, information disclosure and Information leakage on social networks were studied. Models and algorithms types and their repetition in articles have been distinguished and this study builds a research model to examine privacy concerns and the effect of it on self-disclosure. The need of having knowledge and skill about privacy protection seems to be necessary with social networks technology developments. Most of the researches have been studied about privacy protection scope related to users’ privacy on social networks including women, men, children and adults in smartphone and E-health. Most of researches on this scope have been done in USA. Most studies were focused on privacy protection and security on social networks.
    Keywords: Privacy Protection, Social Networks, Information Leakage. Information Disclosure, Tools, Algorithms
  • A. Zare Ghadi (Ms) Valipour, M. Biglari Pages 1274-1282
    The present study carefully examined entropy generation during wustite pellet reduction to sponge iron. The finite volume method was used to solve the governing equations. The grain model was used to simulate the reaction rate. The reactant gases including carbon monoxide and hydrogen were converted to water and carbon dioxide after wustite reduction. Entropy is generated by heat transfer, mass transfer and chemical reactions. The rate of entropy generation is studied over a period of 150 minutes. Based on the governing equations, the share of each process in the generation of entropy was calculated. The effects of gas ratio, porosity, and tortuosity and grain diameter of wustite pellet on entropy generation were investigated. The porosity was changed from 0.2 to 0.5, tortuosity from 1 to 4, grain diameter from 7 to 20 mm and the ratio of reducing gas from 0.5 to 2. According to the results maximum value of entropy generation nearly occurs during first 20 minutes of the reduction process. It is shown that the heat transfer had the highest contribution to entropy generation. The results also indicates porosity and gas ratio are inversely proportional to the rate of entropy generation while tortuosity and grain diameter are directly proportional to entropy generation rate.
    Keywords: Wustite Pellet, Entropy Generation, Mathematical Model, Grain Model
  • A. Rahmani Pages 1283-1291
    Application of artificial neural network (ANN) in forward kinematic solution (FKS) of a novel co-axial parallel mechanism with six degrees of freedom (6-DOF) is addressed in Current work. The mechanism is known as six revolute-spherical-universal (RSU) and constructed by 6-RSU co-axial kinematic chains in parallel form. First, applying geometrical analysis and vectorial principles the kinematic model is extracted and inverse kinematics solution is done. Due to highly nonlinear characteristic of the model, forward kinematic solution for 6-RSU is so complicated. Therefore, ANN based on wavelet analysis, as a powerful solution, is designed and applied to solve FK problem. The minimum prediction risk principle with using final prediction error (FPE) is applied to find the best and optimum topology of our proposed neural network (WNN) in this paper. Furthermore, proposed wavelet WNN is developed to approximate the specific reference trajectories for manipulated platform of mechanism and the results are obtained. Comparing the extracted results by WNN with closed form solution (CFS) demonstrates the accuracy and efficiency of the proposed WNN.
    Keywords: Wavelet Neural Network, Kinematic Analysis, 6, RSU Parallel Mechanism, Final Prediction Error
  • S. Sadripour, M. Estajloo, S. A. Hashemi, M. Adibi Pages 1292-1301
    In present study, experimental measurements and mathematical modeling were employed to investigate the different parameters, such as temperature of different parts of oven, natural gas consumption, flue gases temperature and portion of different heat transfer mechanisms during baking, in two different traditional flatbread bakeries called Sangak (/sӑngӑk/) and Barbari (/bӑrbӑri/). In all studied ovens, the bread receives the energy from natural and forced convections, conduction, and radiation (volumetric and surface radiation). The main aim of this study is introduction of a numerical simulation in order to investigate and validate the flatbread bakery ovens. This validation has resulted in to analyze different bakery ovens using numerical methods and consequently reduce the experiments costs. Due to fulfill this demand two numerical models are used and solved using control volume method based on SIMPLE algorithm and RNG k-ε method. The obtained results showed that numerical solution can make a reliable result in case of modeling bakery ovens, because of a good agreement between numerical and experimental results with the maximum error of 12.57%.
    Keywords: Bakery oven, Flatbread, Energy, Natural gas, Experimental, CFD