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

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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

Community Perception and Adaptation to Safe Drinking Water Scarcity: Salinity, Arsenic, and Drought Risks in Coastal Bangladesh

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International Journal of Disaster Risk Science 2014年第2期5卷 110-124页

作者： anwarul Abedin Umma Habiba Rajib Shaw Graduate School of Global Environmental Studies Kyoto UniversityYoshida HonmachiSakyo-KuKyoto 606-8501Japan

One of the most serious resource and health issues in coastal communities of Bangladesh is the scarcity of safe drinking water, triggered by the combined effects of salinity, arsenic, and drought. This article explores community perception of vulnerabilities in daily life, livelihood, and environment, and investigates how communities and institutions cope with or adapt to drinking water scarcity. This study outlines community expectations for support from government and nongovernment organizations to overcome this problem. The findings reveal that nearly all respondents from the drinking water scarcity area perceive that salinity is the primary reason for the lack of safe drinking water compared to arsenic and drought hazards. Despite a number of socioeconomic factors and a geographical location that aggravates the coastal communities’ vulnerability, these communities have established their own adaptation mechanism to cope with this *** and nongovernment organizations have also supported community efforts to cope with the problem. By emphasizing both community adaptation methods and efforts of institutions, this article illustrates an integrated community-based approach, which would be effective for reducing drinking water scarcity in the southwestern coastal region of the country.

关键词： coastal salinity drought

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 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

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

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

Study on the Evolution of Plane Shape of Guangfu Ancestral Hall Buildings and the Construction of Type Genealogy in the Ming and Qing Dynasties

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Journal of Architectural Research and Development 2024年第1期8卷 1-7页

作者： Yanming Chen Sharul azim Sharudin Rui Chen Faculty of Creative Industries City University Malaysia46100 Petaling JayaSelangorMalaysia College of Forestry and Landscape Architecture South China Agricultural UniversityGuangzhou 510642Guangdong ProvinceChina

This paper studies the clan temples in four periods,namely,the development period(early Ming Dynasty and before),the shaping period(mid-Ming Dynasty to early Qing Dynasty),the maturity period(mid-Qing Dynasty),and the programmed period(late Qing Dynasty),analyzes and summarizes their prototypical planform features and attempts to summarize and construct a genealogy of the architectural characteristics of the plane shape of clan *** the Ming and Qing dynasties,Guangfu ancestral halls in general showed a journey of development from a centripetal-single-linear-multi-linear-grid pattern,forming the unique Guangsanlu classic pattern in the Guangfu area.

关键词： Guangfu clan Ancestral halls Plane shape Genealogy

Insights into ligand expression heterogeneity across multiple cell types in the adult forebrain that regulates neural stem cell behavior

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Neural Regeneration Research 2019年第8期14卷 1369-1371页

作者： Rainer Akkermann Kasum azim Department of Neurology and Neuroregeneration Medical FacultyHeinrich-Heine-University

In the adult mammalian central nervous system (CNS), neural cell generation is restricted to two highly specialized germinal niches. These are the subventricular zone (SVZ) that borders the forebrain lateral ventricles and the subgranular zone of the hippocampus. In the case of the former niche, the SVZ gives rise daily to thousands of migratory neuroblasts that travel long distances to the olfactory bulb via the rostral migratory stream. Neural stem cells (NSCs) first engage through a sequence of activation phe no types and give rise to transiently amplifying progenitors (TAPs) that subsequently differentiate into neuroblasts. Once in the olfactory bulb, they generate phenotypically distinct neurons. Most of these constitute the interneuron class that is preferentially derived from the lateral portion of the SVZ, whilst a small proportion of projection neurons are also formed from the dorsal SVZ.

关键词： Insights ligand expression cell behavior