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A novel technology for control of variable speed pumped storage power plant

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Journal of Central South University 2016年第8期23卷 2008-2023页

作者： seyed mohammad Hassan Hosseini mohammad reza Semsar Department of Electrical Engineering Islamic Azad University

Variable speed pumped storage machines are used extensively in wind power plant and pumped storage power plant. This paper presents direct torque and flux control(DTFC) of a variable speed pumped storage power plant(VSPSP). By this method both torque and flux have been applied to control the VSPSP. The comparison between VSPSP's control strategies is studied. At the first, a wind turbine with the capacity 2.2 k W and DTFC control strategies simulated then a 250 MW VSPSP is simulated with all of its parts(including electrical, mechanical, hydraulic and its control system) by MATLAB software. In all of simulations, both converters including two-level voltage source converter(2LVSC) and three-level voltage source converter(3LVSC) are applied. The results of applying 2LVSC and 3LVSC are the rapid dynamic responses with better efficiency, reducing the total harmonic distortion(THD) and ripple of rotor torque and flux.

关键词： direct torque and flux control(DTFC) two-level & three-level voltage source converter(2LVSC&3LVSC) variable speed pumped storage power plant(VSPSP)

New insights on the role of chondroitin sulfate proteoglycans in neural stem cell–mediated repair in spinal cord injury

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Neural Regeneration Research 2025年第6期20卷 1699-1700页

作者： seyed Mojtaba Hosseini Soheila Karimi-Abdolrezaee Department of Physiology and Pathophysiology Spinal Cord Research CentreRady Faculty of Health SciencesUniversity of ManitobaWinnipegMBCanada Manitoba Multiple Sclerosis Research Center WinnipegMBCanada Children Hospital Research Institute of Manitoba WinnipegMBCanada

Extensive neurodegeneration is a hallmark of traumatic spinal cord injury (SCI) that underlies permanent sensorimotor and autonomic impairments (Alizadeh et al.,2019).Following the primary impact,the spinal cord undergoes a cascade of secondary injury mechanisms that are driven by disruption of the blood-spinal cord ba rrier,vascula r inju ry,glial reactivity,neu roinfla mmation,oxidative stress,lipid peroxidation,and glutamate excitotoxicity that culminate in neuronal and oligodendroglial cell death,demyelination,and axonal damage(Alizadeh et al.,2019).To achieve a meaningful functional recovery after SCI,regeneration of new neurons and oligodendrocytes and their successful growth and integration within the neural network are critical steps for reconstructing the damaged spinal cord tissue (Fischer et al.,2020).

关键词： peroxidation Fischer injury

New approach to solving master equations of density operator for the Jaynes Cummings model with cavity damping

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Chinese Physics B 2014年第9期23卷 65-70页

作者： seyed Mahmoud Ashrafi mohammad reza Bazrafkan Physics Department Faculty of ScienceI.K.I.University

By introducing thermo-entangled state representation Ⅰη〉, which can map master equations of density operator in quantum statistics as state-vector evolution equations, and using ＂dissipative interaction picture＂ we solve the master equation of Jaynes-Cummings model with cavity damping. In addition we derive the Wigner function for density operator when the atom is initially in the up state Ⅰ↑〉 and the cavity mode is in coherent state.

关键词： Jaynes-Cummings model entangled state representation master equations

Presentation of massive orbital hidrocystoma at birth:case report and review of the literature

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Eye and Vision 2017年第1期4卷 22-25页

作者： Bahram Eshraghi mohammad-Ali abtahi seyed Ali Sonbolastan Zahra Kasaie seyed-Hossein abtahi Ophthalmology Department School of MedicineTehran University of Medical SciencesTehranIran Ophthalmology Department School of MedicineIsfahan University of Medical SciencesIsfahanIran Isfahan Eye Research Center Isfahan University of Medical SciencesFeiz HospitalQods Sq.IsfahanIran Pathology Department School of MedicineIsfahan University of Medical SciencesIsfahanIran

Background:Hidrocystoma,or sudoriferous cyst,is an eyelid tumor originating from apocrine or eccrine sweat *** presence in the orbit is relatively *** presentation:A full-term female child with severe right eye extrusion was referred to our department two hours after *** performed cyst aspiration under ultrasonic guidance;15 cc straw-colored fluid was obtained and proptosis resolved *** magnetic resonance imaging(MRI)showed a large unilocular retrobulbar mass with hypo-intensity in T1 and hyper-intensity in *** case underwent further daily ocular assessment until day 5;when proptosis began to worsen *** day 6,under general anesthesia,we performed aspiration and then the cyst was completely removed with an intact wall through a trans-conjunctival *** diameter of the aspirated cyst was about 4 *** pathologic consultation,a cystic cavity lined by a layer of sweat duct like epithelium with apical snouts consistent with the diagnosis of apocrine hidrocystoma was ***:To date,in the literature,six other cases of orbital hidrocystoma have been reported in childhood with protean clinical pictures;none of which presented at ***,we introduce the first case report at birth and also provide a review on the *** report strongly argues against the well reputed theory of traumatic origin for orbital hidrocystoma;it has been postulated that this tumor may be the result of sweat gland cells implantation through the *** thereby suggest the possible presence of choristomatous ectopic sweat gland cells in the orbit during embryogenesis.

关键词： Orbital hidrocystoma Pediatric orbital tumor Sudoriferous cyst

Unraveling a Driven Damped Harmonic Oscillator through Entangled State Representation

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Chinese Physics Letters 2013年第11期30卷 22-24页

作者： seyed Mahmoud Ashrafi mohammad reza Bazrafkan Department of Physics Faculty of ScienceI.K.I.UniversityQazvinIran

Employing the thermo-entangled state representation,the common eigenstates of relative position and the total momentum of a two-mode system,we solve the master equation of a damped harmonic oscillator driven by a time... 详细信息

关键词： field momentum harmonic

Multidisciplinary design optimization of a dual-spin guided vehicle

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Defence Technology（防务技术） 2024年第7期37卷 133-148页

作者： Jalal Karimi mohammad reza Rajabi seyed Hossein Sadati seyed Mahid Hosseini Department of Aerospace Engineering Malek Ashtar University of TechnologyTehranIran

In this research,a Multidisciplinary Design Optimization approach is proposed for the dual-spin guided flying projectile design considering external and internal parts of the body as design *** this way,a parametric formulation is *** related disciplines,including structure,aerodynamics,guidance,and control are *** total mass,maximum aerodynamic control effectiveness,minimum miss distance,maximum yield stress in all subsystems,controllability and gyroscopic stability constraints are some of objectives/constraints taken into *** problem is formulated in All-At-Ones Multidisciplinary Design Optimization approach structure and solved by Simulated Annealing and minimax *** optimal configurations are evaluated in various *** resulted optimal configurations have met all design objectives and constraints.

关键词： Flying projectile optimal design All-at-ones multidisciplinary optimization Structure discipline Guidance and control discipline Aerodynamic discipline

Numerical analysis of reactive turbulent flow in the thrust chamber of RD-108 engine rocket

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Defence Technology（防务技术） 2019年第4期15卷 565-575页

作者： seyed reza Taghavi mohammad Ali Dehnavi Ali Ghafouri Department of Chemical Engineering Imam Hossein Comprehensive University

Combustion chamber modeling and simulation of the liquid propellant engine with kerosene as fuel and liquid oxygen as an oxidizer in the turbulent flow field are performed by CFD *** flow is modeled as Single-phase in steady state and using RNG k-ε turbulence *** results are validated by experimental data of thrust,special impulse and combustion chamber *** comparing t.^wo reaction models of finite rate chemistry and frozen model with experimental data,it is concluded that finite rate chemistry has acceptable *** optimum value of equivalence ratio(oxidizer to fuel ratio)per reaction and operational parameters of the engine which maximize thrust and special impulse are determined.

关键词： Liquid propellant engine Computational fluid dynamics(CFD) Kerosene and oxygen Freeze model Finite rate chemistry model

Potassium forms in calcareous soils as affected by clay minerals and soil development in Kohgiluyeh and Boyer-Ahmad Province,Southwest Iran

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Journal of Arid Land 2018年第2期10卷 217-232页

作者： Sirous SHAKERI seyed A abtahi Department of Agriculture Payame Noor UniversityTehran 19395-3697Iran Department of Soil Science College of AgricultureShiraz UniversityShiraz 71964-84334Iran

Potassium（K） is known as one of the essential nutrients for the growth of plant species. The relationship between K and clay minerals can be used to understand the K cycling, and assess the plant uptake and potential of soil K fertility. This study was conducted to analyze the K forms（soluble, exchangeable, non-exchangeable and structural） and the relationship of K forms with clay minerals of calcareous soils in Kohgiluyeh and Boyer-Ahmad Province, Southwest Iran. The climate is hotter and drier in the west and south of the province than in the east and north of the province. A total of 54 pedons were dug in the study area and 32 representative pedons were selected. The studied pedons were mostly located on calcareous deposits. The soils in the study area can be classified into 5 orders including Entisols, Inceptisols, Mollisols, Alfisols and Vertisols. The main soil clay minerals in the west and south of the study area were illite, chlorite and palygorskite, whereas they were smectite, vermiculite and illite in the north and east of the province. Due to large amount of smectite and high content of organic carbon in soil surface, the exchangeable K in surface soils was higher than that in subsurface soils. It seems that organic matter plays a more important role than smectite mineral in retaining exchangeable K in the studied soils. Non-exchangeable K exhibited close relationships with clay content, illite, vermiculite and smectite. Although the amount of illite was the same in almost all pedons, amounts of structural and non-exchangeable K were higher in humid regions than in arid and semi-arid regions. This difference may be related to the poor reservoir of K~＋ minerals like palygorskite and chlorite together with illite in arid and semi-arid regions. In humid areas, illite was accompanied by vermiculite and smectite as the K~＋ reservoir. Moreover, the mean cumulative non-exchangeable K released by CaCl_2 was higher than that released by oxalic acid, which may be

关键词： clay minerals potassium forms calcareous soils oxalic acid K+ reservoir Iran

Spray Pyrolysis Deposition of ZnO Thin Films from Zinc Chloride Precursor Solution at Different Substrate Temperatures

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Acta Metallurgica Sinica(English Letters) 2015年第1期28卷 110-114页

作者： Fahimeh Zahedi reza Sabet Dariani seyed mohammad Rozati Department of Physics Alzahra University Department of Physics University of Guilan

ZnO films were prepared at different substrate temperatures through spraying pyrolysis deposition of zinc chloride precursor onto glass substrate. Substrate temperature affects surface morphology of films and therefore their optical and electrical properties. All films are polycrystalline with Wurtzite crystal structure and preferentially grow along c-axis direction. Formation of ZnO rods start at about 500 °C. The diameter and length of rods deposited at 500 °C are350–500 and 550–700 nm, respectively. By increasing substrate temperature, film becomes more coverage and diameter of the rods reduces to 250–300 nm but their length increases to 1,000–1,200 nm, respectively. Optical transmission in visible region decreases with increasing substrate temperature. An ultraviolet emission and two visible emissions at 2.82 and2.37 eV are observed for photoluminescence spectra at room temperature. The resistivity of ZnO films increases with increasing substrate temperature due to surface morphology.

关键词： ZnO Rods Spray pyrolysis Substrate temperature Surface morphology