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Preparation and Characterization of New Antibacterial Polyester Composites

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材料科学与工程（中英文A版） 2011年第6期1卷 865-868页

作者： Azadeh Azadbakht amir reza Abbasi Electrochemistry Research Lab Department of Chemistry Faculty of Science Khorramabad Branch Islamic Azad UniversityKhorramabad Iran

Concerning The Effect of Surface Material on Nucleate Boiling Heat Transfer of R-113

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Journal of Electronics Cooling and Thermal Control 2011年第2期1卷 22-27页

作者： reza Hosseini amir Gholaminejad Mahdi Nabil 不详

This paper presents results of an experimental investigation carried out to determine the effects of surface material on nucleate pool boiling heat transfer of refrigerant R113. Experiments were performed on horizontal circular plates of brass, copper and aluminum. The heat transfer coefficient was evaluated by measuring wall superheat and effective heat flux removed by boiling. The experiments were carried out in the heat flux range of 8 to 200 kW/m2. The obtained results have shown significant effect of surface material, with copper providing the highest heat transfer coefficient among the samples, and aluminum the least. There was negligible difference at low heat fluxes, but copper showed 23% better performance at high heat fluxes than aluminum and 18% better than brass.

关键词： Boiling Heat Transfer R-113 Nucleate Boiling Surface Material

Applying data mining techniques to classify patients with suspected hepatitis C virus infection

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Intelligent Medicine 2022年第4期2卷 193-198页

作者： reza Safdari amir Deghatipour Marsa Gholamzadeh Keivan Maghooli Health Information Management Department School of Allied Medical SciencesTehran University of Medical SciencesTehranIran Health Information Management and Medical Informatics Department School of Allied Medical SciencesTehran University of Medical SciencesTehranIran Department of Biomedical Engineering Science and Research BranchIslamic Azad UniversityTehranIran

Background Hepatitis C virus(HCV)has a high prevalence worldwide,and the progression of the disease can cause irreversible damage to severe liver damage or even ***,developing prediction models using machine learning techniques is *** study was conducted to classify suspected patients with HCV infection using different classification *** The study was conducted using a dataset derived from the University of California,Irvine(UCI)Ma-chine Learning *** the HCV dataset was imbalanced,the synthetic minority oversampling technique(SMOTE)was applied to balance the *** cleaning the dataset,it was divided into training and test data for developing six classification *** six algorithms included the support vector machine(SVM),Gaus-sian Naïve Bayes(NB),decision tree(DT),random forest(RF),logistic regression(LR),and K-nearest neighbors(KNN)*** Python programming language was used to develop the *** operating characteristic curve analysis and other metrics were used to evaluate the performance of the proposed *** After the evaluation of the models using different metrics,the RF classifier had the best performance among the six *** accuracy of the RF classifier was 97.29%.Accordingly,the area under the curve(AUC)for LR,KNN,DT,SVM,Gaussian NB,and RF models were 0.921,0.963,0.953,0.972,0.896,and 0.998,respectively,RF showing the best predictive *** Various machine learning techniques for classifying healthy and unhealthy patients were used in this ***,the developed models might identify the stage of HCV based on trained data.

关键词： Data mining methods Classification Hepatitis Hepatitis C virus

Elastic Mechanical Stress Analysis in a 2D-FGM Thick Finite Length Hollow Cylinder with Newly Developed Material Model

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Acta Mechanica Solida Sinica 2016年第2期29卷 178-191页

作者： amir Najibi Mohammad Hassan Shojaeefard Faculty of Mechanical Engineering Semnan University School of Mechanical Engineering Iran University of Science & Technology

In this paper a new 2D-FGM material model based on Mori-Tanaka scheme and third-order transition function has been developed for a thick hollow cylinder of finite *** mechanical stress analysis is performed by utilizing the finite element *** corresponding material,displacement and stress distributions are evaluated for different values of nr and ***,the effects of different material property distributions on the effective stress with respect to the metallic phase volume fraction are *** is demonstrated that the increase in nr and V_m leads to a significant reduction in the effective ***,it is shown that the ceramic phase rich cylinder wall has lower maximum effective stresses of which the lowest value of effective stress has been evaluated for nr=20 and nz=*** minimum value is about half the maximum effective stress which has been evaluated for the non-FGM cylinder case（nr=nz=0.1）.

关键词： 2D-FGM elastic analysis thick hollow cylinder Mori-Tanaka material model

GA-based approach to phase compensation of large phased array antennas

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Journal of Systems Engineering and Electronics 2018年第4期29卷 723-730页

作者： ZAHEDI amir ABBASI ARAND Bijan Department of Electrical and Computer Engineering Tarbiat Modares University

The investigation of the effect of electrical and mechanical errors on the performance of a large active phased array antenna is studied. These errors can decrease the antenna performance, for instance, the gain reduction, side lobe level enhancement, and incorrect beam direction. In order to improve the performance of the antenna in the presence of these errors, phase error correction of large phased array antennas using the genetic algorithm（GA） is implemented. By using the phase compensation method, the antenna overall radiation pattern is recovered close to the ideal radiation pattern without error. By applying the simulation data to a 32×40 array of elements with a square grid at the frequency of S-band and measurement of the radiation pattern, the effectiveness of the proposed method is verified.

关键词： antenna genetic algorithm (GA) phased array radi-ating element.

A capillary force model for interactions between two spheres

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Particuology 2011年第4期9卷 381-386页

作者： amir Farrokh Payam Morteza Fathipour Nano-Electronics Center of Excellence School of Electrical & Computer Engineering Faculty of Engineering University of Tehran

Based on the method of energy principle, an analytical approach for computing the capillary force for sphere/sphere geometry is presented in this paper. In modeling the capillary force, we consider spheres with both equal and non-equal radii, for both symmetric and asymmetric configurations at liquid/solid interfaces. We use numerical analysis to investigate the validity and efficiency of the derived model. The effect of various parameters including humidity, distance between two spheres, radii of spheres and contact angles on the meniscus force are investigated. Finally the results obtained from the model are compared with experimental measurements, and the accuracy and precision of the presented approach is verified.

关键词： Interaction Capillary force Humidity Energy methods Sphere particle

Particle swarm optimization model to predict scour depth around a bridge pier

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Frontiers of Structural and Civil Engineering 2020年第4期14卷 855-866页

作者： Shahaboddin SHAMSHIRBAND amir MOSAVI Timon RABCZUK Department for Management of Science and Technology Development Ton Duc Thang UniversiyHo Chi Minh CityVietmam Faculty of Information Technology Ton Duc Thang UniversityHo Chi Minh CityVietnam Institute of Automation Kando Kalman Faculy of Electrical EngineeringObuda UniversiyBudapest 1034Hungary Department of Mathematics and Informatics J.Selye UniversityKomarno 94501Slovakia School of the Built Environment Oxford Brookes UniversityOxford OX30BPUK Instiute of Structural Mechanics Bauhaus-Universitat WeimarWeimar 99423Germany

Scour depth around bridge piers plays a vital role in the safety and stability of the *** former approaches used in the prediction of scour depth are based on regression models or black box models in which the first one lacks enough accuracy while the later one does not provide a clear mathematical expression to easily employ it for other situations or ***,this paper aims to develop new equations using particle swarm optimization as a metaheuristic approach to predict scour depth around bridge *** improve the efficiency of the proposed model,individual equations are derived for laboratory and field ***,sensitivity analysis is conducted to achieve the most effective parameters in the estimation of scour depth for both experimental and filed data *** the results of the proposed model with those of existing regression-based equations reveal the superiority of the proposed method in terms of accuracy and ***,the ratio of pier width to flow depth and ratio of d50 (mean particle diameter)to flow depth for the laboratory and field data were recognized as the most effective parameters,*** derived equations can be used as a suitable proxy to estimate scour depth in both experimental and prototype scales.

关键词： scour depth bridge design and construction particle swarm optimization computational mechanics artificial intelligence bridge pier

Insights into kinetic inhibition effects of MEG,PVP,and L-tyrosine aqueous solutions on natural gas hydrate formation

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Petroleum Science 2021年第2期18卷 495-508页

作者： amir Saberi Abdolmohammad Alamdari Ali Rasoolzadeh amir H.Mohammadi Department of Natural Gas Engineering School of Chemical and Petroleum EngineeringShiraz UniversityShiraz71345Iran Department of Process Engineering National Iranian Gas Company(NIGC)South Pars Gas Complex(SPGC)Phases 4&5Bushehr75391/311Iran Discipline of Chemical Engineering School of EngineeringUniversity of KwaZulu-NatalHoward College CampusKing George V AvenueDurban4041South Africa

It is necessary to understand all the prerequisites, which result in gas hydrate formation for safe design and control of a variety of processes in petroleum industry. Thermodynamic hydrate inhibitors (THIs) are normally used to preclude gas hydrate formation by shifting hydrate stability region to lower temperatures and higher pressures. Sometimes, it is difficult to avoid hydrate formation and hydrates will form anyway. In this situation, kinetic hydrate inhibitors (KHIs) can be used to postpone formation of gas hydrates by retarding hydrate nucleation and growth rate. In this study, two kinetic parameters including natural gas hydrate formation induction time and the rate of gas consumption were experimentally investigated in the presence of monoethylene glycol (MEG), L-tyrosine, and polyvinylpyrrolidone (PVP) at various concentrations in aqueous solutions. Since hydrate formation is a stochastic phenomenon, the repeatability of each kinetic parameter was evaluated several times and the average values for the hydrate formation induction times and the rates of gas consumption are reported. The results indicate that from the view point of hydrate formation induction time, 2 wt% PVP and 20 wt% MEG aqueous solutions have the highest values and are the best choices. It is also interpreted from the results that from the view point of the rate of gas consumption, 20 wt% MEG aqueous solution yields the lowest value and is the best choice. Finally, it is concluded that the combination of PVP and MEG in an aqueous solution has a simultaneous synergistic impact on natural gas hydrate formation induction time and the rate of gas consumption. Furthermore, a semi-empirical model based on chemical kinetic theory is applied to evaluate the hydrate formation induction time data. A good agreement between the experimental and calculated hydrate formation induction time data is observed.

关键词： Gas hydrate Clathrate hydrate Natural gas Kinetic hydrate inhibitor(KHI) Induction time Kinetics

Predictive value and main determinants of abnormal features of intraoperative cholangiography during cholecystectomy

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Hepatobiliary & Pancreatic Diseases International 2011年第3期10卷 308-312页

作者： Shahram Yousefpour Azary Heshmat Kalbasi Ali Setayesh Mirhadi Mousavi Asad Hashemi Mahsa Khodadoostan Mohammad reza Zali amir Houshang Mohammad Alizadeh Research Center for Gastroenterology and Liver Diseases Shahid Beheshti University of Medical SciencesTaleghani Hospital Arad General Hospital

BACKGROUND:The major issue with intraoperative cholangiography (IOC) is whether its diagnostic accuracy for common bile duct (CBD) stones matches that of other diagnostic procedures,and thus,whether it will become a routine diagnostic *** current study aimed to address the main determinants of CBD stone diagnosis in IOC among an Iranian ***:In a retrospective review database-based study conducted in Taleghani Hospital in Tehran between 2006 and 2008,baseline data and perioperative information of 2060 patients (male to female ratio 542:1518,mean age 53.7 years) who were candidates for cholecystectomy and underwent concomitant IOC for confirming CBD stones were *** predictive power of this procedure for diagnosis of abnormal biliary ducts with the focus on biliary stones was ***:Overall mortality and morbidity following cholecystectomy in the study population were 0.6% and 2.6%,*** early mortality and morbidity due to cholecystectomy were higher in male than *** prevalence of CBD stones in IOC was 3.4% (5.2% in male and 2.8% in female,P=0.008).Among those without gallstones,8.7% had CBD stones and only 3.1% had concomitant gallstones and CBD *** main predictors of stone appearance as an abnormal feature of IOC during cholecystectomy were:advanced age (OR=1.022,P=0.001),male gender (OR=1.498,P=0.050),history of abdominal surgery (OR=1.543,P=0.040) and preoperative endoscopic retrograde cholangiopancreatography (OR=5.400,P<0.001).CONCLUSIONS:IOC is a safe and accurate method for the assessment of bile duct anatomy and ***,the routine use of IOC within cholecystectomy seems reasonable and is recommended.

关键词： intraoperative cholangiography common bile duct stone cholecystectomy predictive value diagnostic accuracy