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Correlation of the mean activity coefficient of aqueous electrolyte solutions using an equation of state

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Chinese Journal of Chemical Engineering 2016年第10期24卷 1456-1463页

作者： seyed Hossein Mazloumi Chemical Engineering Department Faculty of EngineeringFerdowsi University of Mashhad

Accurate calculation of thermodynamic properties of electrolyte solution is essential in the design and optimization of many processes in chemical industries. A new electrolyte equation of state is developed for aqueous electrolyte solutions. The Carnahan-Starling repulsive model and an attractive term based on square-well potential are adopted to represent the short range interaction of ionic and molecular species in the new electrolyte EOS. The long range interaction of ionic species is expressed by a simplified version of Mean Spherical Approximation theory （MSA）. The new equation of state also contains a Born term for charging free energy of ions. Three adjustable parameters of new eEOS per each electrolyte solution are size parameter, square-well potential depth and square-well potential interaction range. The new eEOS is applied for correlation of mean activity coefficient and prediction of osmotic coefficient of various strong aqueous electrolyte solutions at 25℃ and 0.1 MPa. In addition, the extension of the new eEOS for correlation of mean activity coefficient and solution density of a few aqueous electrolytes at temperature range of 0 to 100℃ is carried out.

关键词： Aqueous electrolyte solution Electrolyte equation of state Activity coefficient Osmotic coefficient Solution density

Creep rupture assessment for Level-2 PSA of a 2-loop PWR： accounting for phenomenological uncertainties

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Nuclear Science and Techniques 2017年第8期28卷 117-125页

作者： Faramarz Yousefpour seyed Mohsen Hoseyni seyed Mojtaba Hoseyni seyed Ali Hashemi Olia Kaveh Karimi Nuclear Science and Technology Research Institute TehranIran Young Researchers and Elite Club East Tehran BranchIslamic Azad University Tehran Iran

The Level-2 probabilistic safety assessment(PSA) of pressurized water reactors studies the possibility of creep rupture for major reactor coolant system components during the course of high pressure severe accident sequences. The present paper covers this technical issue and tries to quantify its associated phenomenological uncertainties for the development of Level-2 PSA. A framework is proposed for the formal quantification of uncertainties in the Level-2 PSA model of a PWR type nuclear power plant using an integrated deterministic and PSA approach. This is demonstrated for estimation of creep rupture failure probability in station blackout severe accident of a 2-loop PWR, which is the representative case for high pressure sequences. MELCOR 1.8.6 code is employed here as the deterministic tool for the assessment of physical phenomena in the course of accident. In addition, a MATLAB code is developed for quantification of the probabilistic part by treating the uncertainties through separation of aleatory and epistemic sources of *** probability for steam generator tube creep rupture is estimated at 0.17.

关键词：模型不确定性蠕变断裂 PSA 压水堆断裂评价二级现象学反应堆冷却剂系统

Application of computational fluid dynamics in design of viscous dampers-CFD modeling and full-scale dynamic testing

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Earthquake Engineering and Engineering Vibration 2023年第4期22卷 1065-1080页

作者： Hassan Lak seyed Mehdi Zahrai seyed Mohammad Mirhosseini Ehsanollah Zeighami Department of Civil Engineering Collage of EngineeringArak BranchIslamic Azad UniversityArak ***Iran School of Civil Engineering College of EngineeringUniversity of TehranTehran ***Iran

Computational fluid dynamics(CFD)provides a powerful tool for investigating complicated fluid *** paper aims to study the applicability of CFD in the preliminary design of linear and nonlinear fluid viscous *** fluid viscous dampers were designed based on CFD *** first device was a linear viscous damper with straight *** second was a nonlinear viscous damper containing a one-way pressure-responsive valve inside its *** dampers were detailed based on CFD simulations,and their internal fluid flows were ***-scale specimens of both dampers were manufactured and tested under dynamic *** to the tests results,both dampers demonstrate stable cyclic behaviors,and as expected,the nonlinear damper generally tends to dissipate more energy compared to its linear *** compatibility was achieved between the experimentally measured damper force-velocity curves and those estimated from CFD *** a thermography camera,a rise in temperature of the dampers was measured during the *** was found that output force of the manufactured devices was virtually independent of temperature even during long duration ***,temperature dependence can be ignored in CFD models,because a reliable temperature compensator mechanism was used(or intended to be used)by the damper manufacturer.

关键词： fluid viscous damper passive control dynamic testing energy dissipation device computational fluid dynamic thermography

Success criteria analysis in support of probabilistic risk assessment for nuclear power plants: application on SGTR accident

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Nuclear Science and Techniques 2017年第3期28卷 42-58页

作者： seyed Mohsen Hoseyni Kaveh Karimi seyed Mojtaba Hoseyni Meisam Mohammadnia East Tehran Branch Islamic Azad University Tehran Iran

Success criteria analysis(SCA) bridges the gap between deterministic and probabilistic approaches for risk assessment of complex systems. To develop a risk model,SCA evaluates systems behaviour in response to postulated accidents using deterministic approach to provide required information for the probabilistic model. A systematic framework is proposed in this article for extracting the front line systems success criteria. In this regard, available approaches are critically reviewed and technical challenges are discussed. Application of the proposed methodology is demonstrated on a typical Westinghouse-type nuclear power plant. Steam generator tube rupture is selected as the postulated accident. The methodology is comprehensive and general; therefore, it can be implemented on the other types of plants and complex systems.

关键词： Success criteria analysis Probabilistic safety assessment (PSA) Deterministic safety assessment (DSA) Thermo-hydraulics SGTR

Computational analysis of neutronic effects of ThO_2 rods loaded in CANDU 6 fuel assemblies

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Nuclear Science and Techniques 2016年第4期27卷 14-20页

作者： seyed Mohammad Mirvakili Zohreh Gholamzadeh seyed Amir Hossein Feghhi Reactor Research School Nuclear Science and Technology Research Institute Department of Radiation Application Shahid Beheshti UniversityG.C

Thorium as a suitable fertile with higher natural resources in comparison with uranium resources has been remarkably considered by different nuclear energy user countries in the last decades. Its prominent features such as suitable possibility for power flattening of a nuclear reactor, applicable breeder blanket to produce^(233)U fissile as well as neutron leakage prevention from a nuclear core has caused its application as power flatter, breeder material or other aimed utilizations be evaluated by the researches. In the present study, neutronics of a modeled CANDU 6loaded with Th O_2 and UO_2fuel rods have been computationally studied. The study aimed at reprocessing of burned Th O_2 seeds at CANDU 6 reactor to recover the total produced uranium, which is to be going under another compound fuel cycle. The obtained results showed all the core reactivity coefficients are sufficiently negative. The modeled core 949 GWd burn-up concluding in 99.99 %depletion of^(235)U initial loads. 18.38 kg of^(233) U was produced in the burnt Th O_2 fuel after 1-year burn-up time. In addition, 31.84 kg of^(239) Pu was produced in the UO_2 spent fuel rods after the burn-up time. After a proposed cooling time, about 50.01 kg of^(233)U will be available in the spent Th O_2 fuel.

关键词： CANDU堆中子泄漏燃料组件稳定杆计算核反应堆燃烧时间自然资源

Damage identification in connections of moment frames using time domain responses and an optimization method

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Frontiers of Structural and Civil Engineering 2021年第4期15卷 851-866页

作者： Narges PAHNABI seyed Mohammad seyedPOOR Department of Civil Engineering Shomal UniversityAmol***Iran

Damage is defined as changes to the material and/or geometric properties of a structural system,comprising changes to the boundary conditions and system connectivity,adversely affecting the system’s *** the elements of structures,particularly critical components,is vital to evaluate the structural lifespan and *** this study,an optimization-based method for joint damage identification of moment frames using the time-domain responses is *** beam-to-column connection in a metallic moment frame structure is modeled by a zero-length rotational spring at both ends of the beam *** each connection,an end-fixity factor is specified,which changes between 0 and ***,the problem of joint damage identification is converted to a standard optimization *** objective function is defined using the nodal point accelerations extracted from the damaged structure and an analytical model of the structure in which the nodal accelerations are obtained using the Newmark *** optimization problem is solved by an improved differential evolution algorithm(IDEA)for identifying the location and severity of the *** assess the capability of the proposed method,two numerical examples via different damage scenarios are ***,a comparison between the proposed method and the existing damage identification method is *** outcomes reveal the high efficiency of the proposed method for finding the severity and location of joint damage considering noise effects.

关键词： damage identification beam-to-column connection time-domain response optimization

Three-dimensional heat transfer in a particulate bed in a rotary drum studied via the discrete element method

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Particuology 2020年第4期18卷 155-162页

作者： Esmaeil Yazdani seyed Hassan Hashemabadi Computational Fluid Dynamics(CFD)Research Laboratory School of ChemicalPetroleum and Gas EngineeringIran University of Science and Technology(IUST)16846-13114 TehranIran

We simulated three-dimensional heat transfer inside a horizontal rotating drum using the discrete element method and a thermal conduction *** aim was to determine the effect of end-wall heating on thermal behavior of a granular *** simulation showed that the end-wall heating significantly affects the axial temperature profile of the bed,particularly when the length-to-diameter ratio is *** near the wall heated faster and became more thermally uniform than those in the center of the *** region affected by the end heating gradually increased over *** the rotation speed enhanced the heat conduction rate,and increasing the fill level reduced the mean temperature and thermal uniformity of the granular *** transfer was also simulated for drums with different length-to-diameter ratios.

关键词： Discrete element method Three-dimensional heat transfer Rotary drum Numerical simulation Axial temperature Particulate bed

Prediction of bed load sediments using different artificial neural network models

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Frontiers of Structural and Civil Engineering 2020年第2期14卷 374-386页

作者： Reza ASHEGHI seyed Abbas HOSSEINI Department of Civil Engineering Science and Research BranchIslamic Azad UniversityTehranIran

Modeling and prediction of bed loads is an important but difficult issue in river *** introduced empirical equations due to restricted applicability even in similar conditions provide different accuracies with each other and measured *** this paper,three different artificial neural networks(ANNs)including multilayer percepterons,radial based function(RBF),and generalized feed forward neural network using five dominant parameters of bed load transport formulas for the Main Fork Red River in Idaho-USA were *** optimum models were found through 102 data sets of flow discharge,flow velocity,water surface slopes,flow depth,and mean grain *** deficiency of empirical equations for this river by conducted comparison between measured and predicted values was approved where the ANN models presented more consistence and closer estimation to observed *** coefficient of determination between measured and predicted values for empirical equations varied from 0.10 to 0.21 against the 0.93 to 0.98 in ANN *** accuracy performance of all models was evaluated and interpreted using different statistical error criteria,analytical graphs and confusion *** the ANN models predicted compatible outputs but the RBF with 79%correct classification rate corresponding to 0.191 nctwork error was outperform than others.

关键词： bed load prediction artificial neural network modeling empirical equations

Effect of residual structural strain caused by the addition of Co3O4 nanoparticles on the structural, hardness and magnetic properties of an Al/Co3O4 nanocomposite produced by powder metallurgy

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International Journal of Minerals,Metallurgy and Materials 2020年第3期27卷 384-390页

作者： seyed Rahim Kiahosseini Hossein Ahmadian Department of Engineering Damghan Branch Islamic Azad University

Al composites are of interest due to their appropriate ratio of strength to *** our research,an Al/Co3O4 nanocomposite was generated using a sintering *** powders of Al with various Co3O4 nanoparticle contents(0 wt%,0.5 wt%,1.0 wt%,1.5 wt%,2.0 wt%,and2.5 wt%)were first blended using planetary milling for 30 min,and compressed in a cylindrical steel mold with a diameter of 1 cm and a height of5 cm at a pressure of 80 *** samples were evaluated with X-ray diffractometry(XRD),scanning electron microscopy(SEM),Vickers hardness,and a vibrating sample magnetometer(VSM).Although the crystallite size of the Al particles remained constant at 7–10 nm,the accumulation of nanoparticles in the Al particle interspace increased the structural tensile strain from 0.0045 to 0.0063,the hardness from HV 28 to HV 52 and the magnetic saturation from 0.044 to 0.404 emu/g with an increase in Co3O4 nanoparticle content from 0 wt%to 2.5 wt%.

关键词： Residual strain Vickers hardness vibrating sample magnetometer scanning electron microscopy