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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

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

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

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

Fault ride-through capability improvement in a DFIG-based wind turbine using modified ADRC

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Protection and Control of Modern Power Systems 2022年第1期7卷 751-787页

作者： seyed Reza Mosayyebi seyed Hamid Shahalami Hamed Mojallali Electrical Engineering Department Faculty of EngineeringUniversity of GuilanRashtIran

In this paper,an overview of several strategies for fault ride-through(FRT)capability improvement of a doubly-fed induction generator(DFIG)-based wind turbine is *** and parameter variations have adverse effects on the performance of these *** is desirable to use a control method that is robust to such *** disturbance rejection control(ADRC)is one of the most common methods for eliminating the effects of *** improve the performance of the conventional ADRC,a modified ADRC is introduced that is more robust to disturbances and offers better *** non-derivability of the fal function used in the conventional ADRC degrades its efficiency,so the modified ADRC uses alternative functions that are derivable at all points,i.e.,the odd trigonometric and hyperbolic functions(arcsinh,arctan,and tanh).To improve the effciency of the proposed ADRC,fuzzy logic and fractional-order functions are used *** fuzzy fractional-order ADRC(FFOADRC),all disturbances are evaluated using a nonlinear fractional-order extended state observer(NFESO).The performance of the suggested structure is investigated in MATLAB/*** simulation results show that during disturbances such as network voltage sag/swell,using the modified ADRCs leads to smaller fluctuations in stator flux amplitude and DC-link voltage,lower variations in DFIG velocity,and lower total harmonic distortion(THD)of the stator *** demonstrates the superiority over conventional ADRC and a proportional-integral(PI)***,by chang-ing the crowbar resistance and using the modified ADRCs,the peak values of the waveforms(torque and currents)can be controlled at the moment of fault occurrence with no significant distortion.

关键词： Doubly-fed induction generator(DFIG) Auto disturbance rejection control(ADRC) Fault ride-through(FRT) Wind turbine Nonlinear fractional-order extended state observer(NFESO)

Higher Iterated Hilbert Coefficients of the Graded Components of Bigraded Modules

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Algebra Colloquium 2017年第4期24卷 551-562页

作者： seyed Shahab Arkian University of Kurdistan Pasdaran ST.P.O.Box:416Sanandaj Iran

Let S = K[x1,... ,xn] be the polynomial ring over a field K, and let I C S be a graded ideal. It is shown that the higher iterated Hilbert coefficients of the graded S-modules Tori^S（M,Ik） and Exts^i（M,Ik） are polynomial functions in k, and an upper bound for their degree is given. These results are derived by considering suitable bigraded modules.

关键词： higher iterated Hilbert coefficient bigraded module extension functor tor-sion functor

Effects of herbal medicine in gastroesophageal reflux disease symptoms: a systematic review and meta-analysis

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Traditional Medicine Research 2020年第6期5卷 464-475,I0002,I0003页

作者： Fariba Sadeghi seyed Mohammad Bagher Fazljou Bita Sepehri Laleh Khodaie hassan Monirifar Mojgan Mirghafourvand Department of Persian Medicine School of Traditional Medicine Tabriz University of Medical Sciences Tabriz Iran Liver and Gastrointestinal Diseases Research center Tabriz University of Medical SciencesTabrizIran Department of Traditional Pharmacy Faculty of Traditional MedicineTabriz University of Medical SciencesTabrizIran Horticulture and Crops Research Department East Azarbaijan Agricultural and Natural Resources Research and Education CenterTabrizIran Social Determinants of Health Research Center Tabriz University of Medical SciencesTabrizIran

Background: Pyrosis and regurgitation are the cardinal symptoms of gastroesophageal reflux disease. Severalherbs have been used for treating gastrointestinal disorders worldwide. This systematic review was conducted toinvestigate the effects of medicinal herbs on gastroesophageal reflux disease and adverse events. Methods:MEDLINE (via PubMed;The United States National Library of Medicine, USA), Scopus, ScienceDirect,Cochrane Central Register of Controlled Trials, Web of Science, Magiran, and Scientific Information Databasewere systematically searched for human studies, without a time frame, using medical subject heading terms such as“gastroesophageal reflux disease”, “reflux”, “esophagitis” and “herbs”. Manual searches completed the electronicsearches. Results: Thirteen randomized controlled trials were identified, including 1,164 participants from 1,509publications. In comparing herbal medicine to placebo, there were no significant differences in terms of heartburn(P = 0.23 and 0.48), epigastric or abdominal pain (P = 0.35), reflux syndrome (P = 0.12), and effective rate (P =0.60), but there was a significant difference in terms of acid regurgitation (P = 0.01). In comparing herbal medicineto drugs, there was a significant difference in terms of effective rate (P = 0.001), and there was one trial thatreported a significant difference in terms of epigastric pain (P = 0.00001). Also, in comparing herbal medicine todrugs, there were no significant differences in terms of acid regurgitation (P = 0.39). Conclusion: Thismeta-analysis showed that herbal medicines are effective in treating gastroesophageal reflux disease. Furtherstandardized researches with a large-scale, multicenter, and rigorous design are needed.

关键词： Herbal medicine Gastroesophageal reflux disease Randomized controlled trial Acid regurgitation Effective rate Epigastric pain

Woody Species Diversity and Forest Structure from Lowland to Montane Forest in Hyrcanian Forest Ecoregion

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Journal of Mountain Science 2013年第4期10卷 609-620页

作者： seyed Mohammad JAFARI Shahin ZARRE seyed Kazem ALAVIPANAH School of Biology and Center of Excellence in Phylogeny of Living Organisms College of Science University of TehranP.O. Box 14155-6455 Tehran Iran School of Biology and Center of Excellence in Phylogeny of Living Organisms College of Science University of TehranTehran Iran Department of Cartography Faculty of Geography University of TehranTehran Iran

Alborz Mountains host Caspian Hyrcanian forest ecoregion along the northern slopes and forest steppe ecoregion in highlands. Hyrcanian forest covers the southeastern part of Caucasus biodiversity hotspot and is of great biogeographic importance. Altitudinal pattern and correlation between woody species biodiversity （DIV）, forest structure （（stem density （DEN）, mean basal area （MBA） and mean height class （MHC）） and disturbance （DIS） were explored along 2,4oo m altitudinal gradient in Hyrcanian relict forest, Central Alborz Mountains. Vegetation changes from lowland forest （LoF） to mid- altitude forest （MiF） and montane forest （MoF） in this area. The altitudinal gradient was divided into twelve 200 m elevational belts. Point centered quarter method （PCQM） with 96 sampling points and 83 vegetation samples by plot method （PM） were used to record field data. Shannon-Wiener index and Pearson coefficient were used for diversity and correlation analysis. The results showed that DEN decreased linearly, MBA and MHC showed relatively hump shaped and DIS showed a reverse hump shaped pattern of change along altitudinal gradient. Woody species diversity decreased non-steadily from LoF to MoF. Transitional vegetations of Carpinus-Fagus and Fagus-Quercus represented higher diversity of woody taxa compared to adjacent homogenous communities. Significant correlation was observed between altitude and all parameters： DEN with MBA, DIS and DIV; MBA with DIS; MHC with DIS along with DIV; and DIS with DIV at the study area scale. Surprisingly,correlation between studied parameters differed within each vegetation type. Altitude probably acts as a proxy for human and environmental driving forces in this area. Stability of warm and wet condition, season length, soil depth along with forest accessibility probably influences the altitudinal pattern of the studied parameters. Disturbance affects forest structure and consequently diversity; especially in lowlands. The obtained results recommend

关键词： Alborz Mountains Biodiversity ForestMensuration Hyrcanian forest Disturbance