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Adaptive controller design based on input-output signal selection for voltage source converter high voltage direct current systems to improve power system stability

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Journal of Central South University 2016年第9期23卷 2254-2267页

作者： Abdolkhalegh Hamidi Jamal Beiza Ebrahim babaei Sohrab Khanmohammadi Departement of Electrical Engineering Shabestar Branch Islamic Azad University

An input-output signal selection based on Phillips-Heffron model of a parallel high voltage alternative current/high voltage direct current(HVAC/HVDC) power system is presented to study power system stability. It is well known that appropriate coupling of inputs-outputs signals in the multivariable HVDC-HVAC system can improve the performance of designed supplemetary controller. In this work, different analysis techniques are used to measure controllability and observability of electromechanical oscillation mode. Also inputs–outputs interactions are considered and suggestions are drawn to select the best signal pair through the system inputs-outputs. In addition, a supplementary online adaptive controller for nonlinear HVDC to damp low frequency oscillations in a weakly connected system is proposed. The results obtained using MATLAB software show that the best output-input for damping controller design is rotor speed deviation as out put and phase angle of rectifier as in put. Also response of system equipped with adaptive damping controller based on HVDC system has appropriate performance when it is faced with faults and disturbance.

关键词： input-output signal selection online adaptive damping controller nonlinear high voltage direct current power systemstability

New 4-imino-4H-Chromeno[2,3-d]Pyrimidin-3(5H)-Amine: Synthesis, Cytotoxic Effects on Tumoral Cell Lines and in Silico ADMET Properties

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International Journal of Organic Chemistry 2024年第3期14卷 107-122页

作者： Marwa Dhiabi Sirine Karoui mehdi Fakhfakh Souhir Abid Emmanuelle Limanton Rémy Le Guével Thierry Charlier Ludovic Paquin Jean-Pierre Bazureau Houcine Ammar Laboratoire de Chimie Applique: Htrocycles Corps et Polymres Facult des Sciences de Sfax Universit de Sfax Sfax Tunisie Institut des Sciences Chimiques de Rennes Universit de Rennes Campus de Beaulieu Rennes Cedex France Department of Chemistry (Science and Arts): Al Qurayat Al-Jouf University Al Jawf Saudi Arabia S2Wave Platform ScanMAT UAR CNRS Universit de Rennes Campus de Beaulieu Rennes Cedex France ImPACcell Platform Biosit SFR UMS CNRS Inserm Campus de Villejean Rennes France Institut de Recherche en Sant Environnement et Travail IRSET Inserm UMR_S Rennes France

The synthesis of new 4-imino-4H-chromeno[2,3-d]pyrimidin-3(5H)-amine in four steps including one step under microwave dielectric heating is reported. The structural identity of the synthesized compounds was established according to their spectroscopic analysis, such as FT-IR, NMR and mass spectroscopy. These new compounds were tested for their antiproliferative activities on seven representative human tumoral cell lines (Huh7 D12, Caco2, MDA-MB231, MDA-MB468, HCT116, PC3 and MCF7) and also on fibroblasts. Among them, only the compounds 6c showed micromolar cytotoxic activity on tumor cell lines (1.8 50 50 > 25 μM). Finally, in silico ADMET studies ware performed to investigate the possibility of using of the identified compound 6c as potential anti-tumor compound.

关键词： 2-Amino-4H-Chromene 4H-Chromeno[2 3-d]Pyrimidin-3(5H)-Amine Microwave Irradiation Tumoral Cell Line in Silico ADMET

Effect of particles addition to solution of plasma electrolytic oxidation(PEO)on the properties of PEO coatings formed on magnesium and its alloys:A review

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Journal of Magnesium and Alloys 2020年第3期8卷 799-818页

作者： Arash Fattah-alhosseini Razieh Chaharmahali Kazem babaei Department of Materials Engineering Bu-Ali Sina UniversityHamedan 65178-38695Iran

The plasma electrolytic oxidation(PEO)procedure is utilized in order to amend the surface properties of Mg and its *** procedure creates a ceramic coating on the surface applying *** presence of deep pores and porosities in the surface that affect the corrosion resistance of the coatings is one of the PEO procedure *** of the useful methods to decrease porosities of coating and improve its final properties is changing electrolyte conditions based on the presence of micro-and *** present paper reviews the mechanisms of particle adsorption and composition in PEO thin films in addition to the effect of particle addition on the microstructure,composition and corrosion behavior of coatings that were applied on magnesium alloys.

关键词： Plasma electrolytic oxidation(PEO) Nanoparticles Microparticles Corrosion Magnesium

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)

A Study on Flame Forming of Bowl Shaped Surface with Various Spiral Irradiating Schemes

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Acta Mechanica Solida Sinica 2016年第3期29卷 328-336页

作者： mehdi Safari Department of Mechanical Engineering Arak University of Technology

In this paper, various strategies of spiral irradiating scheme for the flame forming of a bowl shaped surface are investigated experimentally and numerically. Experimental work is performed using a flame torch integrated with a 2-axis CNC workstation. The ABAQUS implicit solver is used in the numerical simulation. Three different strategies of the spiral irradiating scheme are investigated for the flame forming of a bowl shaped surface. The first strategy is the Simple spi- ral irradiating scheme, the second is the Rotational spiral irradiating scheme, and the third is the Symmetrical-Rotational spiral irradiating scheme. The results show that using the Symmetrical- Rotational spiral irradiating scheme, a bowl shaped surface with the maximum deformation can be produced, followed by using the Rotational scheme, and the Simple spiral scheme. It is also concluded from the results that the spiral irradiating scheme with Symmetrical-Rotational, Rota- tional and Simple spiral schemes lead to the maximum symmetries in the produced bowl shaped surface, respectively. All the numerical results are in good agreement with the experimental ob- servations.

关键词： flame forming bowl shaped surface spiral irradiating strategy

BLUNT CRACK-TIP ELASTOPLASTIC ZONE OF MIXED MODE FRACTURE

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Acta Mechanica Solida Sinica 2014年第5期27卷 531-541页

作者： mehdi Khojastehpour Department of Biosystems Engineering Ferdowsi University of Mashhad

This article discusses the characterization of fracture process zone at the tip of a blunt crack in elastoplastic materials under mixed mode loading. The analysis includes the description of elastoplastic zone geometry around the blunt crack tip for predicting crack growth direction. The deformed zone appearing at the crack front is described by presenting a criterion based on the subloading surface concept falling within the framework of unconventional plasticity. The mixed mode crack propagates along the minimum value of the elastoplastic region. The present solutions are reduced to those previously reported in literature, when the elastic perfectly plastic material is considered.

关键词： crack fracture elastic plastic materials stress concentration

Human reliability analysis in maintenance team of power transmission system protection

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Protection and Control of Modern Power Systems 2020年第1期5卷 290-302页

作者： mehdi Tavakoli mehdi Nafar Department of Electrical Engineering Marvdasht BranchIslamic Azad UniversityMarvdashtIran

The requirement for reliable electrical energy supply increases continuously because of its vital role in our ***,events due to various factors in the power grid can cause energy supply to be *** of these factors is human error and thus human reliability analysis is a serious element in the *** first step is to identify the roots of human error,on which there has been limited research in this *** this paper,the potential and actual causes of human error in maintenance teams of power transmission system protection are identified and predicted within a framework of human factors analysis and classification system ***,human error factors are ranked to help improve human *** proposed method is implemented in the Fars Electricity Maintenance Company.

关键词： Power transmission system protection Maintenance teams Human reliability HFACS method

Movement of Intransitive Permutation Groups Having Maximum Degree

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Chinese Annals of Mathematics,Series B 2012年第1期33卷 143-148页

作者： mehdi ALAEIYAN mehdi REZAEI School of Mathematics Iran University of Science and Technology

Let G be a permutation group positive integer. Then the movement of G on a set Ω with no fixed points in Ω, and m be a is defined as move（G）：=supГ{[Г^9 ／Г｜｜g ∈ G}. It F was shown by Praeger that if move（G） = m, then ｜Ω｜ ≤ 3m ＋ t - 1, where t is the number of G-orbits on ≤. In this paper, all intransitive permutation groups with degree 3m ＋ t - 1 which have maximum bound are classified. Indeed, a positive answer to her question that whether the upper bound ｜Ω｜ = 3m ＋ t - 1 for ｜Ω｜ is sharp for every t 〉 1 is given.

关键词： Intransitive permutation groups Bounded movement Orbit

Kinetic studies of the oxidative coupling of methane over the Mn/Na_2WO_4/SiO_2 catalyst

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Journal of Natural Gas Chemistry 2009年第1期18卷 25-34页

作者： Seyed mehdi Kamali Shahri Seyed mehdi Alavi Reaction Engineering Lab. Chemical Engineering Department Iran University of Science and Technology Tehran-Iran

Oxidative coupling of methane is a direct way to obtain C2 hydrocarbon, and Mn-Na-W/SiO2 catalyst is the most promising among all the catalysts. The 2%Mn/5%Na2WO4/SiO2 catalyst was prepared by the incipient wetness impregnation method. A 7-step heterogeneous reaction model of the oxidative coupling of methane to C2 hydrocarbons was conducted by co-feeding methane and oxygen at a total pressure of 1 bar over the catalyst. The kinetic measurements were carried out in a micro-catalytic fixed bed reactor. The kinetic data were obtained at the appropriate range of reaction conditions （4 kPa〈Po2 〈20 kPa, 20 kPa〈PcH4〈80 kPa, 800 ℃〈T〈900℃）. The proposed reaction kinetic scheme consists of three primary and four consecutive reaction steps. The conversions of hydrocarbons and carbon oxides were evaluated by applying Langmuir-Hinshelwood type rate equations. Power-law rate equation was applied only for the water-gas shift reaction. In addition, the effects of operating conditions on the reaction rate were studied. The proposed kinetic model can predict the conversion of methane and oxygen as well as the yield of C2 hydrocarbons and carbon oxides with an average accuracy of ± 15%.

关键词： kinetic model oxidative coupling of methane reaction rate