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3D Numerical Modeling of Wave Forces on Tandem Fixed Cylinders Using the BEM

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Journal of Marine Science and Application 2013年第3期12卷 279-285页

作者： mohammad javad Ketabdari mohammad Mahdi Abaiee Ali Ahmadi Faculty of Marine Technology Amirkabir University of TechnologyTehran 15875-4413 Iran Department of Mechanics Sharif University of TechnologyTehran 145888-9694 Iran

In this paper a 3D numerical model was developed to study the complicated interaction between waves and a set of tandem fixed *** fluid was considered to be inviscid and ***,the Helmholtz equation was used as a governing *** boundary element method（BEM） was adopted to discretize the relevant *** boundaries were used in far fields of the study *** waves were generated and propagated towards tandem fixed cylinders to estimate the forces applied on *** attention was paid to consideration of the effect on varying non-dimensional cylinder radius and distance between cylinders,ka and kd on forces and trapped *** middle cylinder wave forces and trapped modes in a set of nine tandem cylinders were validated utilizing analytical *** comparisons confirm the accuracy of the *** results of the inline wave force estimation on n tandem cylinders show that the critical cylinder in the row is the middle one for odd numbers of *** the results show that the critical trapped mode effect occurs for normalized cylinder radiuses close to 0.5 and *** the force estimation for n tandem cylinders confirms that force amplitude of the middle cylinder versus normalized separation distance fluctuates about that of a single cylinder.

关键词： tandem cylinders boundary element method(BEM) wave force diffraction trapped mode Henkel function

Epistemic-Based Investigation of the Probability of Hazard Scenarios Using Bayesian Network for the Lifting Operation of Floating Objects

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Journal of Marine Science and Application 2016年第3期15卷 250-259页

作者： Ahmad Bahoo Toroody mohammad Mahdi Abaiee Reza Gholamnia mohammad javad Ketabdari Faculty of Engineering Kar Higher Education Institute of Qazvin Qazvin *** Iran Faculty of Marine Technology Amirkabir University of Technology Tehran Tehran 15875-4413 Iran Faculty of Health Safety and Environment Shahid Beheshti University of Medical Science Tehran 19395 Iran

Owing to the increase in unprecedented accidents with new root causes in almost all operational areas, the importance of risk management has dramatically risen. Risk assessment, one of the most significant aspects of risk management, has a substantial impact on the system-safety level of organizations, industries, and operations. If the causes of all kinds of failure and the interactions between them are considered, effective risk assessment can be highly accurate. A combination of traditional risk assessment approaches and modern scientific probability methods can help in realizing better quantitative risk assessment methods. Most researchers face the problem of minimal field data with respect to the probability and frequency of each failure. Because of this limitation in the availability of epistemic knowledge, it is important to conduct epistemic estimations by applying the Bayesian theory for identifying plausible outcomes. In this paper, we propose an algorithm and demonstrate its application in a case study for a light-weight lifting operation in the Persian Gulf of Iran. First, we identify potential accident scenarios and present them in an event tree format. Next, excluding human error, we use the event tree to roughly estimate the prior probability of other hazard-promoting factors using a minimal amount of field data. We then use the Success Likelihood Index Method(SLIM) to calculate the probability of human error. On the basis of the proposed event tree, we use the Bayesian network of the provided scenarios to compensate for the lack of data. Finally, we determine the resulting probability of each event based on its evidence in the epistemic estimation format by building on two Bayesian network types: the probability of hazard promotion factors and the Bayesian theory. The study results indicate that despite the lack of available information on the operation of floating objects, a satisfactory result can be achieved using epistemic data.

关键词： epistemic estimation Bayesian theory light-weight lifting success likelihood index method(SLIM) event tree(ET) Bayesian network

Effects of different treatments on seed germination and breaking seed dormancy of Prosopis koelziana and Prosopis Juliflora

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Journal of Forestry Research 2011年第1期22卷 35-38页

作者： Salman Zare Ali Tavili mohammad javad Darini Department of Arid and Mountainous Regions Reclamation Faculty of Natural Resource University of Tehran Karaj Iran

For improving seed germination of Prosopis koelziana and Prosopis juliflora, different treatments of seeds were conducted, including scarification with sulfuric acid 98% for 10 and 15 min, sandy paper, hot water for 5 and 10 min, potasium nitrate 0.1%, gibberellic acid at 250 mg·L^-1 and 500 mg·L^-1 and combinational treatment of scarification with gibberellic acid of 250 mg·L^-1 and 500 mg·L^-1. The results show that scarifications with sandy paper and sulfuric acids 98% were the most effective treatments on breaking seed dormancy and seed germination induction. Scarification with sulfuric acid 98% for 15 min was the best treatment. According to the positive effect of scarification and lack of reaction of seeds against KNO3 and gibberellic acid, the kind of seed dormancy was determined as exogenous.

关键词： breaking seed dormancy seed germination sulfuric acid Prosopis koelziana Prosopis juliflora

AFAR:adaptive fuzzy ant-based routing for communication networks

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第12期9卷 1666-1675页

作者： Seyed javad MIRABEDINI mohammad TESHNEHLAB M.H.SHENASA Ali MOVAGHAR Amir Masoud RAHMANI Engineering Department Science and Research BranchIslamic Azad UniversityTehranIran Control Department K.N.Toosi Technology UniversityTehranIran Computer Department Sharif UniversitTehranIran

We propose a novel approach called adaptive fuzzy ant-based routing (AFAR), where a group of intelligent agents (or ants) builds paths between a pair of nodes, exploring the network concurrently and exchanging obtained information to up-date the routing tables. Routing decisions can be made by the fuzzy logic technique based on local information about the current network state and the knowledge constructed by a previous set of behaviors of other agents. The fuzzy logic technique allows multiple constraints such as path delay and path utilization to be considered in a simple and intuitive way. Simulation tests show that AFAR outperforms OSPF, AntNet and ASR, three of the currently most important state-of-the-art algorithms, in terms of end-to-end delay, packet delivery, and packet drop ratio. AFAR is a promising alternative for routing of data in next generation networks.

关键词： Adaptive fuzzy routing algorithm Swarm intelligence Routing table Communication network Packet delay,Throughput

Quenching effect of deferoxamine on free radical-mediated photon production in luminol and ortho-phenanthroline-dependent chemiluminescence

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Chinese Chemical Letters 2014年第4期25卷 630-634页

作者： Mahdi Parvar Jalil Mehrzadn mohammad javad Chaichi Saman Hosseinkhani Hamid Golchoubian Faculty of Chemistry Mazandaran University Department of Pathobiology Faculty of Veterinary MedicineFerdowsi University of Mashhad Veterinary Biotechnology Research Group Institute of BiotechnologyFerdowsi University of Mashhad Department of Biochemistry Faculty of Biological SciencesTarbiat Modares University

Removing excessive free radicals （FRs） by a synthetic chemical might give a clue for treatment of many iron-mediated diseases. Deferoxamine （DFO） can be one of the chemicals of choice for the clue. To investigate photoredox properties of DFO, its quenching effect on superoxide radical （O2°）, hydrogen peroxide （H202） and hydroxyl radical （OH~） was examined using luminol and ortho-phenanthroline （o- phen） chemiluminescence （CL） systems and UV-vis spectrophotometry. Stern-Volmer equation was also used for the CL kinetics. The observed quenching effect of DFO on CL]photon production in luminol and o-phen CL systems strongly confirmed the static arm of quenching properties of DFO on OH° and H2O2, but much less pronounced on O2^-°; the quenching property was maximal when iron was involved in the reaction systems. The Stern-Volmer plots in the designed photochemical reaction systems also confirmed a potent quenching effect of DFO on FR-mediated CL. Our study highlights strong photoreducing and antioxidant properties of DFO with huge quenching capacity on excessive FRs, and thus implies its promising prospects for therapeutic applications.

关键词： Chemiluminescence Deferoxamine Free radicals Photon production Stern-Volmer plot

Numerical study of n-heptane/benzene separation by thermal diffusion column

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Chinese Journal of Chemical Engineering 2019年第8期27卷 1745-1755页

作者： Neda Hashemipour javad Karimi-Sabet Kazem Motahari Saeed Mahruz Monfared Younes Amini mohammad Ali Moosavian Department of Chemical Engineering Faculty of EngineeringArak UniversityArakIran Material and Nuclear Fuel Research School(MNFRS) Nuclear Science and Technology Research InstituteTehranIran Department of Chemical and Petroleum Engineering Sharif University of TechnologyTehranIran Department of Chemical Engineering Isfahan University of TechnologyIsfahanIran School of Chemical Engineering Faculty of EngineeringUniversity of TehranTehranIran

In this article,numerical simulations are performed to investigate the performance of the thermal diffusion column for the separation of n-heptane/benzene *** present work tried to optimize column by analyzing significant parameters such as feed flow rate,temperature and *** order to obtain the hydrodynamic and temperature and mass distribution inside thermal diffusion column,computational fluid dynamic(CFD) method is applied to solve the Navier-Stocks *** simulations are conducted to study the main parameters in both stationary and time-dependent *** using the separation work unit as a function of cut,the optimal cut for maximum SWU occurs within a limited range of 0.47-0.5 for feed rate between 0.5 and 4 g min^-*** findings reveal that the optimum feed rate in the range of optimum cut is about 1 g min^-*** transient study,results show that the best cut for reaching to steady-state condition is θ=0.5.

关键词： Thermal diffusion column(TDC) Computational fluid dynamic Separative work unit n-Heptane/benzene separation

H pylori infection and reflux oesophagitis: A case-control study

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World Journal of Gastroenterology 2006年第35期12卷 5658-5662页

作者： Rahim Masjedizadeh Eskandar Hajiani Koorosh MoezArdalan Saeed Samie mohammad-javad Ehsani-Ardakani Ali Daneshmand mohammad-Reza Zali Division of Gastroenterology and Hepatology Department of Interna Medicine Ahwaz Jundishapur University of Medical Sciences Ahwaz Iran The National Research Department of Foodborne Diseases(NRDFD) The Research Center of Gastroenterology and LiverDiseases (RCGLD) Shaheed Beheshti University of MedicaSciences Iran

AIM： To examine the relationship between Hpylori and gastro-oesophageal reflux disease （GORD） in Iran. METHODS： In this study 51 GORD patients （referred to endoscopy at Taleghani hospital） were compared with 49 age-sex matched controls. Diagnosis of H pylori was made by gastric mucosal biopsy and rapid urease test （positive if the result of one or both diagnostic methods was positive）. Updated Sydney system was used to report histopathological changes. RESULTS： The frequency of H pylori infection based on rapid urease test and histology was 88.2% （45） in patients and 77.6% （38） in controls, which showed no significant difference. The frequency of H pylori infection was significantly higher in the antrum than in the corpus and cardia. The mean activity, inflammation, and gastritis scores were also higher in the antrum of patients than in the antrum of controls. The mean scores were significantly higher in the corpus of controls than in the corpus of patients. Diffuse active gastritis was observed in a significantly larger number of controls, while the frequency of diffuse chronic gastritis was higher in patients. There in the frequency of other patients and controls. was no significant difference histological findings ***： H pylori infection cannot prevent GORD in this region.

关键词： H pylori Gastro-oesophageal reflux diseases Reflux oesophagitis

Evaluation of hydrogen effect on the fatigue crack growth behavior of medium-Mn steels via in-situ hydrogen plasma charging in an environmental scanning electron microscope

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Journal of Materials Science & Technology 2021年第26期85卷 30-43页

作者： Di Wan Yan Ma Binhan Sun Seyed mohammad javad Razavi Dong Wang Xu Lu Wenwen Song Department of Mechanical and Industrial Engineering Norwegian University of Science and TechnologyRichard Birkelands vei 2B7491TrondheimNorway Steel Institute(IEHK) RWTH Aachen UniversityIntzestraße 152072AachenGermany Max-Planck-Institut für Eisenforschung GmbH Max-Planck-Straße 140237DüsseldorfGermany

Fatigue crack growth(FCG)tests were conducted on a medium-Mn steel annealed at two intercritical annealing temperatures,resulting in different austenite(γ)to fe rrite(α)phase fractions and differentγ(meta-)*** in-situ hydrogen plasma charging was combined with in-situ cyclic loading in an environmental scanning electron microscope(ESEM).The in-situ hydrogen plasma cha rging increased the fatigue crack growth rate(FCGR)by up to two times in comparison with the reference tests in *** investigations showed a brittle-like crack growth or boundary cracking manner in the hydrogen environment while a ductile transgranular manner in *** both materials,the plastic deformation zone showed a reduced size along the hydrogen-influenced fracture path in comparison with that in *** difference in the hydrogen-assisted FCG of the medium-Mn steel with different microstructures was explained in terms of phase fraction,phase stability,yielding strength and hydrogen *** refined study can help to understand the FCG mechanism without or with hydrogen under in-situ hydrogen charging conditions and can provide some insights from the applications point of view.

关键词： Hydrogen embrittlement Fatigue crack growth(FCG) Electron channeling contrast imaging(ECCI) Medium-Mn steel Hydrogen plasma

Developing a K-value equation for predict dew point pressure of gas condensate reservoirs at high pressure

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Petroleum 2018年第4期4卷 437-443页

作者： Seyedfoad Aghamiri Mohsen Tamtaji mohammad javad Ghafoori Chemical Engineering Department Faculty of EngineeringUniversity of IsfahanIsfahan81744Iran

This paper proposed a new empirical K-value equation is developed to calculate dew pressure for gas condensate *** equation is applicable in the wide ranges of composition,temperature,and pressure by considering the effect of composition via two equations for normal boiling point and critical temperature of the *** range of dew pressure,temperature,heptane plus mole fraction,methane mole fraction,N2 mole fraction,CO2 mole fraction,and H2S mole fraction are fallen into 2666.7e9655 Psia,40e350.87F,0.0021e0.213,0.3344e0.9668,0e0.4322,0e0.0864,and 0e0.942 *** an important point,the proposed equation has any adjustable parameters,in addition,this equation indicates that in order to predict of dew pressure of gas condensate reservoirs,trial and error was not needed and therefore,computational speed increases beyond the ***,the accuracy is validated by comparing against the experimental data of 81 gas condensate reservoirs samples from published literature and the results of Wilson,Whitson,and Ghafoori *** to the experimental data,the absolute average deviations of dew pressure calculations for the proposed equation,Wilson,Whitson,and Ghafoori were 7.6%,97.6%,99.4%,and 94.9%respectively.

关键词： Dew point pressure Gas condensate reservoirs K-value Wilson