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Casting fluidity,viscosity,microstructure and tensile properties of aluminum matrix composites with different Mg_(2)Si contents

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Rare Metals 2022年第8期41卷 2767-2776页

作者： reza Vatankhah Barenji Department of Industrial Engineering Hacettepe UniveristyBeytepe Campus06800AnkaraTurkey

The effect of Mg_(2)Si amount on the properties of Al-Mg_(2)Si as-cast composites was investigated in this *** with different amounts of Mg_(2)Si(15 wt%,20 wt%and 25 wt%)were fabricated,and the fluidity,viscosity,porosity formation and tensile properties were then *** addition,optical microscope and scanning electron microscope were used for micros tructural studies and *** results reveal that with the amount of Mg_(2)Si increasing,the morphology of the primary Mg_(2)Si becomes irregular,the size of primary Mg_(2)Si increases,fluidity decreases,viscosity increases,and porosity amount *** reason for the higher amounts of porosities is the lower fluidity and higher *** addition,Al-15%Mg_(2)Si shows better tensile properties and higher quality index compared to other ***,the fracture surface of the composite with lower Mg_(2)Si amount reveals more ductile mode than those with higher Mg_(2)Si amount.

关键词： Al-Mg_(2)Si Microstructure Fluidity Tensile behavior Porosity

Aircraft robust multidisciplinary design optimization methodology based on fuzzy preference function

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Chinese Journal of Aeronautics 2018年第12期31卷 2248-2259页

作者： Ali reza BABAEI Mohammad reza SETAYANDEH Hamid FARROKHFAL Department of Mechanical and Aerospace Engineering Malek-Ashtar University of Technology

This paper presents a Fuzzy Preference Function-based Robust Multidisciplinary Design Optimization(FPF-RMDO) methodology. This method is an effective approach to multidisciplinary systems, which can be used to designer experiences during the design optimization process by fuzzy preference functions. In this study, two optimizations are done for Predator MQ-1 Unmanned Aerial Vehicle(UAV):(A) deterministic optimization and(B) robust optimization. In both problems, minimization of takeoff weight and drag is considered as objective functions, which have been optimized using Non-dominated Sorting Genetic Algorithm(NSGA). In the robust design optimization, cruise altitude and velocity are considered as uncertainties that are modeled by the Monte Carlo Simulation(MCS) method. Aerodynamics, stability and control, mass properties, performance, and center of gravity are used for multidisciplinary analysis. Robust design optimization results show 46% and 42% robustness improvement for takeoff weight and cruise drag relative to optimal design respectively.

关键词： Fuzzy logic Multidisciplinary design optimization Preference function Robust design Unmanned Aerial Vehicle(UAV)

Assessment of Physico-Chemical and Microbial Quality of Sugarcane Juice Sold by Street Vendors in Three Regions of Bangladesh

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Food and Nutrition Sciences 2024年第4期15卷 263-276页

作者： Nargis Akter Khan Md. Murtaja reza Linkon Munni Akter Md. Alamgir Hossain Md. Mahbubur Rahman Tayeba Khan Md. Abdul Alim Md. Esrafil Department of Food Technology and Nutritional Science Mawlana Bhashani Science and Technology University Tangail Bangladesh Department of Biotechnology and Genetic Engineering Mawlana Bhashani Science and Technology University Tangail Bangladesh

Sugar cane juice is a popular refreshing drink in most part of Bangladesh. It has great taste and health benefits;also it is available most of the public places at reasonable prices which consumed by road side customers including general public, shopping personals, tourists, students. In our country, street vendors crushing sugarcane between roller crusher and sold without any heat treatment or preservative, also served with or without added ice and lemon juice. The study aimed to identify and compare the physico-chemical and microbial quality of sugarcane juice. The chemical qualities of juices including moisture, PH, ash, total soluble solid, total sugar, reducing sugar and titrable acidity were found slightly different in Mymensingh, Gazipur and Narayangonj areas. The highest and lowest value of moisture, ash, PH, total soluble solids, total sugar, reducing sugar and titrable acidity were found in 84.33% - 79.26% (Gazipur-Mymensingh), 0.57% - 0.04% (Mymensingh-Gazipur), 5.9 - 2.9 (Gazipur-Narayangonj), 17.48% - 4.98% (Mymensingh-Narayangonj), 21.9% - 6.56% (Mymensingh-Gazipur), 3.7 - 2.1 (Gazipur-Mymensingh) and 0.523% - 0.007% (Narayangonj-Gazipur) respectively. For microbiological analysis, the total viable count of sugar cane juice in Mymensingh, Gazipur and Narayangonj were ranged from 0.6 × 105 - 43.6 × 105 cfu/ml, 4.6 × 105 - 21.6 × 105 cfu/ml and 3.6 × 105 - 36.6 × 105 cfu/ml respectively, where the permitted value is 1.0 × 104 cfu/ml, whereas the total coliform count was ranged from 0.4 × 105 - 6.4 × 105 cfu/ml, 0.6 × 105 - 8.4 × 105 cfu/ml and 0.00 - 8.4 × 105 cfu/ml, where the permitted value is 100 cfu/ml and total fungal count was ranged from 5.5 × 105 - 56.5 × 105 cfu/ml, 21.5 × 105 - 54.5 × 105 cfu/ml and 32.5 × 105 - 68.5 × 105 cfu/

关键词： Sugarcane Street Vendors Microbial Quality Reducing Sugar

Stochastic Linear Programming for Optimal Planning of Battery Storage Systems Under Unbalanced-uncertain Conditions

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Journal of Modern Power Systems and Clean Energy 2020年第5期8卷 971-980页

作者： reza Hemmati Hasan Mehrjerdi Department of Electrical Engineering Kermanshah University of TechnologyKermanshahIran Qatar University DohaQatar

Battery energy storage system(BESS)has already been studied to deal with uncertain parameters of the electrical systems such as loads and renewable ***,the BESS have not been properly studied under unbalanced operation of power *** paper aims to study the modelling and operation of BESS under unbalanced-uncertain conditions in the power *** proposed model manages the BESS to optimize energy cost,deal with load uncertainties,and settle the unbalanced loading at the same *** three-phase unbalanced-uncertain loads are modelled and the BESSs are utilized to produce separate charging/discharging pattern on each phase to remove the unbalanced *** IEEE 69-bus grid is considered as case *** load uncertainty is developed by Gaussian probability function and the stochastic programming is adopted to tackle the *** model is formulated as mixed-integer linear programming and solved by GAMS/*** results demonstrate that the model is able to deal with the unbalanced-uncertain conditions at the same *** model also minimizes the operation cost and satisfies all security constraints of power grid.

关键词： Battery energy storage system(BESS) singlephase storage planning unbalanced loading uncertainty

Effect of synthesis solution pH of Co/γ-Al_2O_3 catalyst on its catalytic properties for methane conversion to syngas

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燃料化学学报 2018年第3期46卷 311-318页

作者： Amir Mosayebi reza Abedini Department of Chemical Engineering Tafresh University Faculty of Chemical Engineering Babol Noshirvani University of Technology

The cobalt nanoparticles over γ-Al_2O_3 support were prepared via chemical reduction of CoCl_2·6H_2O using NaBH_4 with various values of pH in the range of 11. 92-13. 80. Synthesized catalysts were studied through X-ray diffraction( XRD),N_2 adsorption/desorption( BET),H_2-temperature programmed reduction( H_2-TPR),H_2-chemisorption,O_2 pulse titration and temperature programmed oxidation( TPO) methods. Obtained results exhibited the synthesis solution pH showed a significant influence on the activity and selectivity in partial oxidation of methane reaction. The methane conversion,CO selectivity and H_2 yield were enhanced by increasing of the synthesis solution pH. Compared to other catalysts,the catalyst that synthesized at pH of 13.80,showed a superior ability in syngas production with a H_2/CO ratio of near 2 and also a proper stability against deactivation during the partial oxidation of methane.

关键词：部分氧化 Co/-Al 2 O 3 nanoparticles 选择 pH 价值

Robust D-Stability Test of LTI General Fractional Order Control Systems

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IEEE/CAA Journal of Automatica Sinica 2020年第3期7卷 853-864页

作者： reza Mohsenipour Xinzhi Liu Department of Aerospace Engineering Sharif University of TechnologyTehran ***Iran Department of Applied Mathematics University of WaterlooOntario N2L 3G1Canada

This work deals with the robust D-stability test of linear time-invariant(LTI) general fractional order control systems in a closed loop where the system and/or the controller may be of fractional order. The concept of general implies that the characteristic equation of the LTI closed loop control system may be of both commensurate and non-commensurate orders, both the coefficients and the orders of the characteristic equation may be nonlinear functions of uncertain parameters, and the coefficients may be complex numbers. Some new specific areas for the roots of the characteristic equation are found so that they reduce the computational burden of testing the robust D-stability. Based on the value set of the characteristic equation, a necessary and sufficient condition for testing the robust D-stability of these systems is derived. Moreover, in the case that the coefficients are linear functions of the uncertain parameters and the orders do not have any uncertainties, the condition is adjusted for further computational burden reduction. Various numerical examples are given to illustrate the merits of the achieved theorems.

关键词： Fractional order control system LTI system robust D-stability value set

Introducing an effective coherence function to generate non-uniform ground motion on topographic site using time-domain boundary element method

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Earthquake Engineering and Engineering Vibration 2021年第1期20卷 89-100页

作者： Mohsen Isari reza Tarinejad Faculty of Civil Engineering University of TabrizTabrizEast Azerbaijan ProvinceIran

In this study,a comprehensive parametric analysis was performed on non-uniform excitation of V-shaped topography using the boundary element method in time *** this purpose,wave scattering analysis was carried out on a topography subjected to the SV-wave for different predominant frequencies and shape *** on the numerical results,new coherence and time delay functions are proposed to generate non-uniform ground motion for topographic *** efficiency and accuracy of the proposed functions for real engineering problems are indicated by comparison with observations reported in previous literature.

关键词： site effect time delay boundary element method amplification coherence function

Effect of methane content and the oscillating electric field between electrodes on atmospheric Ar/methane plasma jet and DLC coating deposition

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Plasma Science and Technology 2020年第8期22卷 76-89页

作者： reza SAFARI Farshad SOHBATZADEH Department of Atomic and Molecular Physics Faculty of Basic SciencesUniversity of MazandaranBabolsar 47416Iran

In this work,the effects of the methane gas flow and the internal oscillating electric field between electrodes on radio-frequency(RF)atmospheric pressure argon/methane plasma jet and process of diamond-like carbon(DLC)film deposition have been *** of RF atmospheric Ar/methane plasma jet such as active species density,length,electron temperature,appearance and ionization process of argon/methane plasma jet are changed due to the changing of methane flow content and electric field vector and its *** increasing methane flow,the formation of C2 hydrocarbon and CH band content is decreased because injected electrical energy to a mixture of Ar/methane gases is insufficient to stabilize the ionization process of methane gas and the electrical-chemical reaction rate is *** shortening the gas gap between two electrodes,electric field strength and its gradient are increased leading to more energy injection to the ***-chemical reactions are strengthened leading to increasing the CH band *** phenomena introduce the Ar/methane plasma jet in different modes causing to deposit the DLC film with different structures and *** using quartz glass and alumina ceramic as dielectric barriers tubes,RF atmospheric pressure Ar/methane plasma jet has been used to deposit DLC coating in different *** methane content and shortening the gas gap leads to decreasing sp3 bonded content and the quality of the deposited film.

关键词： RF atmospheric plasma methane flow electric field

Stochastic price based coordinated operation planning of energy storage system and conventional power plant

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Journal of Modern Power Systems and Clean Energy 2019年第5期7卷 1020-1032页

作者： Mohammad reza SHEIBANI Gholam reza YOUSEFI Mohammad Amin LATIFY Department of Electrical and Computer Engineering Isfahan University of TechnologyIsfahan 84156-83111Iran

A generation company(GENCO)which has a conventional power plant(CPP)intends to add an energy storage system(ESS)beside the CPP to increase its flexibility and *** this purpose,a new model is proposed for coordinated operation planning of the CPP and ESS in energy and spinning reserve markets in the presence of a bilateral *** proposed model is based on the stochastic price based unit commitment(PBUC)and price based storage commitment(PBSC).The uncertainties of the energy and spinning reserve prices and delivery requests in the spinning reserve market are modeled via scenarios based upon historical *** proposed model maximizes the profitability of the ESS beside the CPP and encourages the GENCO to invest the *** technology options to use beside the CPP are determined by economic *** results show that utilization of ESSs improves the technical operation of CPPs,as well as GENCOs’profitability.

关键词： Energy storage system Conventional power plant Operation planning Price based unit commitment