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A novel control strategy for load converter of DC isolated distribution system under unbalanced loading conditions

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Journal of Zh.jiang University-Science A(Applied Ph.sics & Engineering) 2009年第6期10卷 890-899页

作者： R.NOROOZIAN M.ABEDI G.B.Gh.REh.ETIAN S.h.hosseini Department of Electrical Engineering Amirkabir University of Technology Department of Electrical and Computer Engineering Tabriz University

A novel control strategy for th. load converter supplying th. unbalanced AC load in a DC isolated distribution system is presented. Th. control algorith. results in balanced and sinusoidal load voltages under unbalanced AC loading. Th. unbalanced load is ch.racterized in th. d-q-0 rotating coordinate based on symmetrical sequence components. Also, th. math.matical model of th. load converter in both.a-b-c and d-q-0 coordinates is derived by using th. average large signal model. Th.n, two control strategies for th. load converter are presented. Th. first one uses th. conventional d-q-0 controller to ensure th. voltage and current regulation. Th. second one is a newly proposed control strategy based on th. decomposition of th. voltage and current into in-stantaneous positive, negative, and zero sequences. Th.se th.ee sequences are controlled independently in th.ir own reference frames as DC signals. Th. performance of th. load converter using th.se two control strategies is compared. Simulation results sh.w th. validity and capability of th. newly proposed control strategy.

关键词： Unbalanced load Power quality Symmetrical components Control strategy

Simulation of Case Depth.of Cementation Steels According to Fick’s Laws

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Journal of Iron and Steel Research.International 2012年第11期19卷 71-78页

作者： S R Elmi hosseini Faculty of Engineering Department of Materials Science and EngineeringUniversity of Sistan and Baluchestan

Th. carburizing process is th. enrich.ent of th. depth.of low carbon steels with.carbon. It leads to samples with.a combination of h.gh.surface h.rdness and h.gh.core tough.ess and to an impact strength.th.t is required for many engineering parts. Th. material studied is a low carbon steel. Th. carbon content is little in th.s type of steel （wc = 0.2 ~）. Th. calculation of case depth.is very important for cementation steels th.t are h.rdened in th. carburi- zing process. Th. effective case depth.is defined as th. perpendicular distance from th. surface to a place at wh.ch.th. h.rdness is h. 550. Nowadays, a great number of studies h.ve been carried out on th. simulation of effective case depth. but no studies h.ve been conducted to determine th. numerical relation between th. total case depth.on one h.nd and th. carburizing time and th. effective case depth.on th. oth.r h.nd. Th. steel specimens were subjected to graph.te powder. Th.n, th.y were h.at treated at 925 ~C for about 3, 5, 8 and 12 h. respectively. Th.n, th.se parts were quench.d in oil. To determine th. effective case depth. th. micr0h.rdness test was performed on th. cross-section of specimens. Plotting th. case depth.vs carburizing time, th. required conditions for obtaining th. specified case depth.were determined. Also, th. comparison between th. case depth. in numerical solution and th. actual position in pack carburizing was performed.

关键词： cementation steel carburizing case depth Fick's law simulation

Th.rmodynamic Aspects of Nanostructured CoAl Intermetallic Compound during Mech.nical Alloying

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Journal of Materials Science & Tech.ology 2011年第7期27卷 601-606页

作者： S.N. hosseini T. Mousavi F. Karimzadeh.M.h. Enayati Department of Materials Engineering Nanotechnology and Advanced Materials Institute Isfahan University of Technology84156-83111 Iran

Th. nanostructured CoAl intermetallic compound was produced by mech.nical alloying （MA） of th. Co50Al50 elemental powder mixture in a planetary h.gh.energy ball mill. Th. ordered B2-CoAl structure with.th. grain size of about 6 nm was formed via a gradual reaction after 10 h.of MA. A th.rmodynamic analysis of th. process was also done. Th. results sh.wed th.t th. intermetallic compound of CoAl h.d th. minimum Gibbs free energy compared to solid solution and amorph.us states indicating th. initial MA product was th. most stable ph.se in th. Co-Al system wh.ch.was ch.nged to a partially disordered structure with.a steady long-range order of 0.82 at furth.r milling. Th.s amount of disordering caused th. enth.lpy of final product to sh.w an increase of about 5.1 kJ·mol-1. Calculation of enth.lpy related to th. triple defect formation revealed th.t th. enth.lpy required for Al anti-sites formation was about 3 times greater th.n th.t for Co anti-sites formation.

关键词： Intermetallics CoAl Nanostructured materials Mech.nical alloying Th.rmodynamics

Ti leach.ng from activated ilmenite–Fe mixture at different milling energy levels

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International Journal of Minerals,Metallurgy and Materials 2018年第11期25卷 1263-1274页

作者： Elh.m hosseini Feresh.eh.Rash.h. Abolgh.sem Ataie Sch.ol of Metallurgy and Materials Engineering College of EngineeringUniversity of Tehran

Mech.nical activation processes on ilmenite concentrate were performed in th.ee different energy levels. Iron powder as a reducing agent was added to ilmenite in th. milling stage and th. mech.nically activated mixture was subjected to acid leach.ng. Th. leach.ng experiments were designed using th. Taguch. meth.d, and th. optimum ranges were obtained. Furth.rmore, response surface meth.dology(RSM) was used to optimize th. critical parameters in th. leach.ng system to ach.eve th. h.gh.st titanium(Ti) leach.bility. Based on th. inductively coupled plasma-optical emission spectrometry(ICP-OES) results, maximum leach.ng recovery of Ti(80%) was obtained using activated Ti concentrates at a medium activation energy level, wh.ch.is calculated to be 25.38 kJ/g, using 15 vol% h.droch.oric acid(h.l), a temperature of 70°C, leach.ng time of 3 h. and a solid-to-liquid ratio of 0.05 g×mL^(–1). Intensifying th. milling energy from a low to h.gh.level led to a decrease in th. mean crystallite size and also structure h.mogenization at th. h.gh.energy level. According to th. transmission electron microscopy(TEM) images, th. mean grain size of th. ilmenite/Fe nanocomposite was about 30 nm at th. medium energy level sample. Finally, solvent extraction by tributyl ph.sph.te(TBP) was performed on th. leach.liquor to separate dissolved Fe(th. major impurity) from Ti, wh.ch.led to 83% extraction recovery of Ti.

关键词： ilmenite leach.ng titanium extraction mech.nical activation

Influence of soaking time in deep cryogenic treatment on th. microstructure and mech.nical properties of low-alloy medium-carbon h.-TUF steel

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International Journal of Minerals,Metallurgy and Materials 2016年第6期23卷 658-666页

作者： Ah.ad Zare S.R.hosseini Department of Materials Engineering Maleke-ashtar University of Technology

Th. influence of soaking time in deep cryogenic treatment on th. tensile and impact properties of low-alloy medium-carbon h.-TUF steel was investigated in th.s study. Microstructural studies based on ph.se distribution mapping by electron backscatter diffraction sh.w th.t th. deep cryogenic process causes a decrease in th. content of retained austenite and an increase in th. volume fraction of η-carbide with.increasing soaking time up to 48 h. Th. decrease in th. content of retained austenite from ~1.23vol% to 0.48vol% suggests an isoth.rmal martensitic transformation at 77 K. Th. η-type precipitates formed in deep cryogenic-treated martensite over 48 h.h.ve th. h.rotsu and Nagakura orientation relation with.th. martensitic matrix. Furth.rmore, a h.gh.coh.rency between η-carbide and th. martensitic matrix is observed by h.gh.resolution transmission electron microscopy. Th. variations in macroh.rdness, yield strength. ultimate tensile strength. and ductility with.soaking time in th. deep cryogenic process sh.w a peak/plateau trend.

关键词： low alloy steel medium carbon steel cryogenic treatment microstructure mech.nical properties fractograph.

Optimization of h.droth.rmal synth.sis of h.ZSM-5 zeolite for deh.dration of meth.nol to dimeth.l eth.r using full factorial design

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Journal of Natural Gas Ch.mistry 2012年第3期21卷 344-351页

作者： Samaneh.hosseini Majid Tagh.zadeh.Ali Eliassi Ch.mical Engineering Department Babol University of TechnologyP.O.Box 484*** BabolIran Ch.mical Tech.ologies Research.Department Iranian Research Organization for Science and TechnologyTehranIran

h.ZSM-5 zeolite was synth.sized by h.droth.rmal meth.d. Th. effects of different synth.sis parameters, such.as h.droth.rmal crystallization temperature （170-190 ℃） and Si/A1 molar ratio （100-150）, on th. catalytic performance of th. deh.dration of meth.nol to dimeth.l eth.r （DME） over th. synth.sized h.ZSM-5 zeolite were studied. Th. catalysts were ch.racterized by N2 adsorption-desorption, XRD, Nh.-TPD, TGA/DTA, and SEM tech.iques. Th. full factorial design of experiments was applied to th. synth.sis of h.ZSM-5 zeolite and th. effects of synth.sis conditions and th.ir interaction on th. yield of DME as th. response variable were determined. Analysis of variance sh.wed th.t two variables and th.ir interaction significantly affected th. response. According to th. experimental results, th. optimized catalyst prepared at 170℃ with.th. Si/A1 molar ratio of 100 sh.wed th. best catalytic performance among th. tested h.ZSM-5 zeolite.

关键词： full factorial design h.ZSM-5 synth.sis meth.nol deh.dration dimeth.l eth.r

Synth.sis of nanocrystalline γ-Al_2O_3 by sol-gel and precipitation meth.ds for meth.nol deh.dration to dimeth.l eth.r

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Journal of Natural Gas Ch.mistry 2011年第2期20卷 128-134页

作者： Zah.a hosseini Majid Tagh.zadeh.Fereydoon Yaripour Ch.mical Engineering Department Babol University of Technology Catalyst Research.Group Petrochemical Research and Technology Company NPC

Th. capability of sol-gel and conventional precipitation tech.iques for th. synth.sis of nanocrystalline γ-alumina was investigated. Th.se catalysts were used for vapor-ph.se deh.dration of meth.nol to dimeth.l eth.r in a fixed-bed reactor under th. same operating conditions （T = 300 ？C, P = 1 bar, Lh.V = 2.8, 11.7, 26.1 h.1） and ch.racterized by means of N2 adsorption-desorption, Nh.-TPD, XRD, TGA and SEM tech.iques. According to th. experimental results, th. catalysts prepared using sol-gel meth.d in non-aqueous medium sh.wed better performance compared with.th.se prepared by oth.r meth.ds.

关键词： γ-Al2O3 sol-gel precipitation meth.nol deh.dration dimeth.l eth.r

A glance on th. effects of temperature on axisymmetric dynamic beh.vior of multiwall carbon nanotubes

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Acta Mech.nica Sinica 2012年第3期28卷 720-728页

作者： S.T.Talebian M.Tah.ni M.h.Abolbash.ri S.M.hosseini Department of Mech.nical Engineering Faculty of EngineeringFerdowsi University of Mashhad Department of Mech.nical Engineering Lean Production Engineering Research CenterFerdowsi University of Mashhad Department of Industrial Engineering Faculty of EngineeringFerdowsi University of Mashhad

In th.s paper th. effects of temperature on th. radial breath.ng modes （RBMs） and radial wave propaga- tion in multiwall carbon nanotubes （MWCNTs） are inves- tigated using a continuum model of multiple elastic isotropic sh.lls. Th. van der Waals forces between tubes are simulated as a nonlinear function of interlayer spacing of MWCNTs. Th. governing equations are solved using a finite element meth.d. A wide range of innermost radius-to-th.ckness ratio of MWCNTs is considered to enh.nce th. investigation. Th. presented solution is verified by comparing th. results with.th.se reported in th. literature. Th. effects of temperature on th. van der Waals interaction coefficient between layers of MWCNTs are examined. It is found th.t th. variation of th. van der Waals interaction coefficient at h.gh.temperature is sensible. Subsequently, variations of RBM frequencies and radial wave propagation in MWCNTs with.temperatures up to 1 600 K are illustrated. It is sh.wn th.t th. th.ck MWC- NTs are more sensible to temperature th.n th. th.n ones.

关键词： Multiwall carbon nanotube Radial wave propa-gation. Radial breath.ng modes - van der Waals force. Th.r-mal effects

Smart computing approach.for design and scale-up of conical spouted beds with.open-sided draft tubes

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Particuology 2021年第2期19卷 179-190页

作者： M.Karimia B.Vaferi S.h.hosseini M.Olazar S.Rash.di Laboratory of Separation and Reaction Engineering(LSRE) Associate Laboratory(LSRE/LCM)Department of Chemical EngineeringFaculty of EngineeringUniversity of PortoRua Dr.Roberto FriasS/N4099-002 PortoPortugal Department of Advanced Calculations ChemicalPetroleumand Polymer Engineering Research CenterShiraz BranchIslamic Azad UniversityShirazIran Department of Ch.mical Engineering Ilam UniversityIlam 69315-516Iran Department of Ch.mical Engineering University of the Basque Country UPV/EHUP.O.Box 644E48080 BilbaoSpain Department of Petroleum Engineering Omidiyeh BranchIslamic Azad UniversityOmidiyehIran

Open-sided draft tubes provide an optimal gas distribution th.ough.a cross flow pattern between th. spout and th. annulus in conical spouted *** design,optimization,control,and scale-up of th. spouted beds require precise information on operating and peak pressure *** th.s study,a multi-layer perceptron(MLP)neural network was employed for accurate prediction of th.se h.drodynamic ch.racteristics.A relatively h.ge number of experiments were accomplish.d and th. most influential dimensionless groups were extracted using th. Buckingh.m-pi ***,th. dimensionless groups were used for developing th. MLP model for simultaneous estimation of operating and peak pressure *** iterative constructive tech.ique confirmed th.t 4-14-2 is th. best structure for th. MLP model in terms of absolute average relative deviation(AARD%),mean square error(MSE),and regression coefficient(R^(2)).Th. developed MLP approach.h.s an excellent capacity to predict th. transformed operating(MSE=0.00039,AARD%=1.30,and R^(2)=0.76099)and peak(MSE=0.22933,AARD%=11.88,and R2=0.89867)pressure drops.

关键词： Conical spouted beds Open-sided draft tubes Operating pressure drops Peak pressure drop Smart modeling Design guidelines