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The Possibility of Wax Formation in Gas Fields:a Case Study

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Journal of Natural Gas Chemistry 2007年第3期16卷 293-300页

作者： Z.Jeirani A.Lashanizadegan sh.Ayatollahi J.Javanmardi School of Chemical and Petroleum Engineering Shiraz UniversityShirazIran School of Chemical Engineering Shiraz University of TechnologyShiraz.Iran

Natural gas production from a gas reservoir （Reservoir A） located in the south of Iran, presents solids deposition during processing because the condensate contains suspended and dissolved solids. Solids deposition occurs not only in the transportation lines from the wells to the separators but also in the various operating units of gas streams and condensate stream. In this study, the multisolid-phase model has been used to predict the wax precipitation from gas and gas condensate fluids. The properties of gas and liquid phases are described using the Soave-Redlich-Kwong （SRK） equation of state. The model is then used to predict the possibility of the wax formation in Reservoir A gas facilities, located at the south of Iran. Solid deposition which occurred in the various streams of that facility confirmed the calculated results. Finally, the wax appearance temperature （WAT）, the weight percent of wax formation and the effects of pressure and temperature on the wax formation were also predicted.

关键词： wax precipitation fluid phase equilibria multisolid model gas condensate

Tameness and Artinianness of Graded Generalized Local Cohomology Modules

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Algebra Colloquium 2015年第1期22卷 131-146页

作者： M. Jahangiri N. shirmohammadi sh. Tahamtan Faculty of Mathematical sciences and Computer Kharazmi University rlbhran Iran School of Mathematics Institute for Research in Fundamental Sciences (IPM) P.O. Box 19395-5749 Tehran Iran School of Mathematics Institute for Research in Fundamental Sciences (IPM) P.O. Box 19395-5749 rlbhran Iran Department of Mathematics University of Tabriz Tabriz Iran Islamic Azad University Borujerd Branch Boroujerd Iran

Let R = ⊙n〉0 Rn be a standard graded ring, a ∩ ⊙n〉0 Rn an ideal of R, and M, N two finitely generated graded R-modules. This paper studies the homogeneous components of graded generalized local cohomology modules. We show that for any i 〉 0, the n-th graded component Hiα（M, N）n of the i-th generalized local cohomology module of M and N with respect to a vanishes for all n 〉〉 0. Some sufficient conditions are pro- posed to satisfy the equality sup{end（Hiα （M, N）） [ i _〉 0} = sup{end（HiR＋（M, N））｜ i 〉 0}. Also, some sufficient conditions are proposed for the tameness of Hiα（M, N） such that i = fRα＋（M,N） or i = cdα（M,g）, where fRα＋（M,N） and cdα（M,g） denote the R＋- finiteness dimension and the cohomological dimension of M and N with respect to a, respectively. Finally, we consider the Artinian property of some submodules and quotient modules of Hjα（M, N）, where j is the first or last non-minimax level of Hiα（M, N）.

关键词： graded rings and modules generalized local cohomology Artinian modules,tameness

Two-dimensional Modeling of a Salt-gradient Solar Pond with Wall shading Effect and Thermo-physical Properties Dependent on Temperature and Concentration

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Journal of Thermal Science 2011年第4期20卷 362-370页

作者： Mohsen Mazidi Mohammad Hassan shojaeefard Mohammad sh.Mazidi Hossein shojaeefard Mechanical Engineering Department Islamic Azad University School of Mechanical Engineering Iran University of Science and Technology Management Business Administration Department Amirkabir University of Technology

In this paper,the behavior of a salt-gradient solar pond with the square cross-section has been studied experimentally and numerically.A small-scale solar pond were designed and built to provide quantitative data.A two-dimensional,transient heat and mass transfer model has been solved numerically by using finite-control-volume *** this study,all the thermo-physical properties are variable as the function of temperature and salt *** results as obtained for the experimental pond have been satisfactorily compared and validated against measured ***,the wall shading effect has been elaborated to improve the agreement between two sets of *** temperature of the storage zone is predicted well by the *** also can be observed that the initial concentration profile is preserved with *** stability of the pond in time has been investigated in order to distinguish the critical ***,the application of an energy analysis gives an efficiency of about 12%for the pond.

关键词： solar energy salt-gradient solar pond transient heat and mass transfer temperature and concentration profiles stability thermal efficiency

Donor safety and remnant liver volume in living donor liver transplantation

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World Journal of Gastroenterology 2012年第48期18卷 7327-7332页

作者： Zheng-Rong sh Lu-Nan Yan Cheng-You Du Department of Hepatobiliary Surgery The First Affiliated HospitalChongqing Medical University Liver Transplantation Division Department of SurgeryWest China HospitalSichuan University

AIM:To evaluate the relationship between donor safety and remnant liver volume in right lobe living donor liver transplantation(LDLT).METHODS:From July 2001 to January 2009,our liver transplant centers carried out 197 *** clinical data from 151 cases of adult right lobe living donors(not including the middle hepatic vein) were *** conditions of the three groups of donors were well matched in terms of the studied *** donors' preoperative data,intraoperative and postoperative data were calculated for the three groups:Group 1 remnant liver volume(RLV) 40%.Comparisons included the different remnant liver volumes on postoperative liver function recovery and the impact of systemic *** between remnant liver volume and post-operative complications were also ***:The donors' anthroposomatology data,op-eration time,and preoperative donor blood test indicators were calculated for the three *** significant differences were observed between the donors' gender,age,height,weight,and operation *** to the Chengdu standard liver volume formula,the total liver volume of group 1 was 1072.88 ± 131.06 mL,group 2 was 1043.84 ± 97.11 mL,and group 3 was 1065.33 ± 136.02 *** three groups showed no statistically significant *** the volume of the remnant liver was less than 35% of the total liver volume,the volume of the remnant had a significant effect on the recovery of liver function and intensive care unit *** addition,the occurrence of complications was closely related to the remnant liver *** the volume of the remnant liver was more than 35% of the total liver volume,the remnant volume change had no significant effect on donor ***:To ensure donor safety,the remnant liver volume should be greater than the standard liver volume(35%) in right lobe living donor liver transplantation.

关键词： Donor safety Remnant liver volume Living donor Liver transplantation Complications grade

Rapid Prototyping of Ceramic Components by Slurry Jet Printing——Ⅰ.

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材料导报 2000年第Z10期14卷 361-363页

作者： Jang,JH Wang,sh

Rapid Prototyping of Ceramic Components by Slurry Jet Printing——Ⅱ.Jet

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材料导报 2000年第Z10期14卷 364-365页

作者： Jang,JH Wang,sh

Numerical Simulation for Refraction-Diffraction of Waves in Water of Slowly Varying Current and Topography

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China Ocean Engineering 1997年第4期12卷 373-386页

作者： Hong, GW Feng, WB Xia, QY Pan, sh Hohai Univ Res Inst Coastal & Ocean Engn Nanjing 210024 Peoples R China

A new numerical finite difference iteration method for refraction-diffraction of waves ia water of slowly varying current and topography is developed in this paper. And corresponding theoretical model including the dissipation term is briefly described, together with some analysis and comparison of computational results of the model with measurements in a hydraulic scale model (Berkhoff et al., 1982). An example of practical use of the method is given, showing that the present model is useful to engineering practice.

关键词： refraction-diffraction of waves on current wave number conservation wave action conservation Eikonal equation time dependent mild slope equation on current energy dissipation

Damage prediction of 7025 aluminum alloy during equal-channel angular pressing

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International Journal of Minerals,Metallurgy and Materials 2014年第10期21卷 990-998页

作者： M.Ebrahimi sh.Attarilar C.Gode F.Djavanroodi Department of Mechanical Engineering Iran University of Science and Technology Department of Materials Engineering Sahand University of Technology School of Denizli Vocational Technology Program of Machine Pamukkale University Department of Mechanical Engineering Imperial College

Equal-channel angular pressing （ECAP） is a prominent technique that imposes severe plastic deformation into materials to en- hance their mechanical properties. In this research, experimental and numerical approaches were utilized to investigate the mechanical prop- erties, strain behavior, and damage prediction of ECAPed 7025 aluminum alloy in various conditions, such as die channel angle, outer comer angle, and friction coefficient. Experimental results indicate that, after the first pass, the yield strength, ultimate tensile strength, and hardness magnitude are improved by approximately 95%, 28%, and 48.5%, respectively, compared with the annealed state, mainly due to grain re- finement during the deformation. Finite element analysis shows that the influence of die channel angle is more important than that of outer comer angle or friction coefficient on both the strain behavior and the damage prediction. Also, surface cracks are the main cause of damage during the ECAP process for every die channel angle except for 90°; however, the cracks initiated from the neighborhood of the central re- gions are the possible cause of damage in the ECAPed sample with the die channel angle of 90°.

关键词： aluminum alloys equal-channel angular pressing materials damage strain distribution mechanical properties

Thermal-hydraulic and stress analysis of AP1000 reactor containment during LOCA in dry cooling mode

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Nuclear Science and Techniques 2017年第6期28卷 73-85页

作者： sh.sheykhi S.Talebi M.Soroush E.Masoumi Department of Energy Engineering and Physics Amirkabir University of Technology(Tehran Polytechnic) Young Researchers and Elite Club Islamic Azad UniversitySouth Tehran Branch

Some kinds of break in the reactor coolant system may cause the coolant to exit rapidly from the failure site,which leads to the loss of coolant accident(LOCA).In this paper,a stress analysis of an AP1000 reactor containment is performed in an LOCA,with the passive containment cooling system(PCCS) being available and not available for cooling the wall's *** variations in the mechanical properties of the wall's containment,including elastic modulus,strength,and stress,are analyzed using the ABAQUS code.A general two-phase model is applied for modeling thermal-hydraulic behavior inside the *** pressure and temperature from thermal-hydraulic models are considered as boundary conditions of the ABAQUS code to obtain distributions of temperature and stress across steel shell of the containment in the *** results indicate that if the PCCS fails,the peak pressure inside the containment exceeds the design ***,the stress would still be lower than the yield stress value,and no risk would threaten the integrity of the containment.

关键词： Two-phase flow LOCA Containment integrity AP1000 reactor