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汽车安全集成

电子产品世界 2012年第8期19卷 15-17页

作者： azim eskandarian 乔治华盛顿大学工程与应用科学学院

本文探讨了主动安全的特点、分类及发展动向。

关键词：主动安全 ESP ACC

Meshless Analysis of Crack Propagation in Multiphase Micromorphic Solid

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Meshless Analysis of Crack Propagation in Multiphase Micromo...

A Survey and Tutorial of EEG-Based Brain Monitoring for Driver State Analysis

The Sixth World Congress on Computational Mechanics in Conjunction with the Second Asian-Pacific Congress on Computational Mechanics

作者： azim eskandarian Morton S.Oskard James D.Lee Center for Intelligent System Research The George Washington University Ashburn VA 20147 USA Turner-Fairbank Highway Research Center Federal Highway Administration U.S.Department of Transportation McLean Virginia 22101 USA Department of Mechanical and Aerospace Engineering The George Washington University Washington DC 20052 USA

The material body considered in this work belongs to a class of multiphase micromorphic solids. In Eringen's micromorphic continuum theory [1], a material body is envisioned as a collection of a large number of finite-size and deformable particles. Each particle has nine degrees of freedom representing stretches and rotations, in addition to the three classical degrees of freedom accounting for the motion of its centroid, and may be considered as a polyatomic molecule, a primitive unit cell of a crystalline solid [2,3], or a chopped fiber in a composite, etc. General micromorphic theory contains specialized micromorphic theory for covalent and ionic crystals [4], micropolar theory, and classical continuum theory as its subcases. In this work, attention is focused on multiphase material such as polycrystalline solid consisting of grains and grain boundaries. Due to the existence of material inhomogeneity, material forces and Eshelby stresses [5] are obtained, that indicate the location of crack initiation. Based on meshless method [6], the problem of mixed mode crack propagation in multiphase micromorphic solid is investigated. Numerical results, showing the path of crack propagation and the ultimate strength of the materials, are presented and discussed.

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Structural Features of(Ce,La or Sr)(Mn or Co)O_3 NanoPerovskites as a Catalyst for Carbon Monoxide Oxidation

IEEE/CAA Journal of Automatica Sinica 2021年第7期

作者： Ce Zhang azim eskandarian

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Acta Metallurgica Sinica(English Letters) 2014年第4期27卷 635-641页

作者： Mahnaz Ghiasi azim Malekzadeh School of Chemistry Damghan University

The collection of different cations in the A and B sites of ABO3 was explored for the regularity of perovskites phase ***,Sr2？,La3？,and Ce4？are selected as the cations of site *** site B is considered to be Mn or Co *** analysis and Fourier transform infrared spectroscopy results confirm the formation of perovskite structure for catalysts in which La3？and Sr2？are considered as the cations of site *** is detected as the main crystalline phase when Ce4？is selected to be cation of site *** is found that the octahedral factor（rB/rO） takes the same important role as the tolerance factor to form cubic *** crystallite size of the products was calculated by data of the XRD and measured by the TEM *** of the XRD and TEM studies were supported by the study of the particles size distribution,which was carried out in a particle size *** perovskite samples were also used for stoichiometric oxidation of carbon monoxide with air.

关键词： Carbon monoxide Nano-perovskite Oxidation Cerium Lanthanum Strontium

Dark count rate and band to band tunneling optimization for single photon avalanche diode topologies

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Chinese Physics B 2019年第6期28卷 458-464页

作者： Taha Haddadifam Mohammad azim Karami Iran University of Science and Technology

This paper proposes two optimal designs of single photon avalanche diodes(SPADs) minimizing dark count rate(DCR). The first structure is introduced as p^+/pwell/nwell, in which a specific shallow pwell layer is added between p^+and nwell layers to decrease the electric field below a certain threshold. The simulation results show on average 19.7%and 8.5% reduction of p^+/nwell structure’s DCR comparing with similar previous structures in different operational excess bias and temperatures respectively. Moreover, a new structure is introduced as n+/nwell/pwell, in which a specific shallow nwell layer is added between n+and pwell layers to lower the electric field below a certain threshold. The simulation results show on average 29.2% and 5.5% decrement of p^+/nwell structure’s DCR comparing with similar previous structures in different operational excess bias and temperatures respectively. It is shown that in higher excess biases(about 6 volts), the n+/nwell/pwell structure is proper to be integrated as digital silicon photomultiplier(dSiPM) due to low DCR. On the other hand, the p^+/pwell/nwell structure is appropriate to be utilized in dSiPM in high temperatures(above 50?C) due to lower DCR value.

关键词： single-photon avalanche diode digital silicon photomultiplier dark count rate

Analytical and statistical calculation of gamma dose rate for the accident of losing the shield for Tehran Research Reactor

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Chinese Physics C 2008年第11期32卷 877-881页

作者： Farshid Tabbakh azim Ahmadinyar School of Nuclear Science Institute of Nuclear Reactors and Accelerators Atomic Energy Organization of Iran North Kargar Av. Tehran Iran

In this paper we study the analytical and statistical results of estimating the gamma dose rate at pool access floor in TRR when the core shield accidentally decreases to some non-permitted levels. Due to the risk of experimental techniques, we use the analytical and statistical methods. In normal conditions （no risk）, the discrepancies between experiment and two methods are justified and it is found that for such problems we have to normalize these methods to experimental results as follows： the analytical method by factor 0.13 and MCNP by 1.7.

关键词： TRR gamma-ray dose rate MCNP4C

A hybrid simulation approach to evaluate stimulation micro-seismic events and production potential of fractured geothermal reservoirs

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Petroleum Research 2020年第2期5卷 131-143页

作者： Reda Abdel azim Petroleum Engineering Department American University of Kurdistan Zakho Rd.99641DohoukIraq

This study presents an integrated approach to simulate fluid flow and to predict the micro seismic eventsduring stimulation and circulation of cold water over a longer term in geothermal reservoirs. The integrated approach based on new three dimensional fully coupled thermo-poroelastic numerical model forevaluation of energy recoverable. In the presented approach, the fracture aperture due to fractureslippage is calculated by shear and dilation. The shear slippage is controlled by the concept of shearfailure using linear Mohr-Coulomb criterion. The numerical model is validated against an analytical Oda’smodel for permeability tensor calculation and against an analytical solution for thermo-poroelasticmodel. The heat transfer between the rock and fluid is modelled by using the conductive heat transferwithin the reservoir rock and convective heat transfer in discrete fractures. The thermal stress changesare included in the model to be studied by using roughness induced shear displacement principle in aporo-thermo-elastic environment. The fracture aperture changes are estimated by using an analyticalmodel based on the distributed dislocation technique. The roughness of fracture surfaces is used in thecalculation of residual fracture aperture. The presented approach is used to study the potential ofpermeability enhancement for Habanero geothermal reservoir at a depth of 3600 m. The result show thatthe increasing in tensile effective stress tend to increase the fracture aperture within the zone of *** increasing in fracture aperture led to significant changes in pressure distribution (decrease inimpedance) and hence, increase in the flow rate.

关键词： Fractured reservoirs Finite element Permeability tensor Fracture aperture Tensile stress Fractal density and dimension

A poroelastic numerical model for simulation of hydraulic fracture propagation:Application to Upper Safa formation-Western Desert-Egypt

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Petroleum Research 2020年第1期5卷 39-51页

作者： Reda Abdel azim Petroleum Engineering Department American University of KurdistanDohoukIraq

The hydraulic fracturing in tight sand formations has a significant importance in improving its production *** this study,a poroelastic numerical model is presented in order to study the reservoirs and rock mechanical properties that affect the propagation of the hydraulic *** poroelastic model simulate fully coupled fluid flow,pressures and stress changes by using finite element *** results show that the formation permeability and fracture toughness are key parameters in the design of hydraulic fracture treatment.A case study applied in Upper Safa formation in a well-located western desert *** formation is very tight with permeability of 0.1md and the objective here is to optimize the design procedures for hydraulic fracture *** results show that the formation needs to be pumped for about 5min to produce hydraulic fracture length of 182 *** addition,the total pumping time(30 min)is vital to produce the desired total fracture length of 1000 ft.

关键词： Fracture propagation Finite element Upper Safa formation Poroelastic Leak off model

Moderate concentration of citric acid for the formation of LaMnO3 and LaCoO3 nano-perovskites

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Journal of Rare Earths 2013年第10期31卷 997-1002页

作者： Elham Ghiasi azim Malekzadeh Mahnaz Ghiasi School of Chemistry Damghan University

Stoichiometric LaMnO3and LaCoO3nanoparticles were synthesized via calcination of a dried solution,containing molar ratio of La(NO3)3·6H2O/[Mn(NO3)2·4H2O or Co(NO3)2·6H2O]=1 and citric acid as disperser at temperature range of 600–900 oC for 5 *** role of organic additive concentration,which was 0.0,1.0,2.5 and 5 times of the total number of moles of the nitrate ions,was investigated on phase formation,morphology,extent of crystallization and particle size of the *** were characterized by X-ray diffraction(XRD),Fourier-transform infrared spectroscopy(FT-IR),scanning electron microscopy(SEM)and transmission electron microscopy(TEM)*** tendency of lanthanum ion toward manganese cation was observed to be more than to cobalt cation for the formation of LaBO3(B:Mn or Co)perovskite phase.A spongy product was formed on perovskite phase formation or in the presence of citric acid.A constructive or destructive effect was observed for the organic disperser on perovskite phase formation,which depended on mole of the citric acid.

关键词： mixed oxides LaMnO3 LaCoO3 nano-perovskite citric acid rare earths