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Numerical prediction of hydrodynamic cavitating flow structures and their corresponding erosion

Journal of hydrodynamics 2021年第3期33卷 546-571页

作者： Amirhossein Mohammadkhani mansour alizadeh Department of Mechanical Engineering Iran University of Science and TechnologyTehranIran

hydrodynamic cavitating flows usually consist of 3-D intense vortical flows that are detached from solid *** vortical flows normally generate heaps of cavitating flow structures,which,in turn,govern the location of cavitation erosion before ***,this study introduces a new numerical approach based on the improved delayed detached eddy simulation(IDDES)turbulence modeling for predicting cavitating ***,the solution of compressible Eulerian-Eulerian two-phase flow and the IDDES turbulence model was linked to the microjet hypothesis and unsteady behavior of pressure and vapor volume to predict the corresponding erosion of cavitating *** method for cavitation erosion prediction,a modified version taken from previous studies,was applied as a post-processing *** validation of cavitating flow predictions was performed for the first time on the Grenoble axisymmetric nozzle by comparing them with 21 photos of cavitation from the previous experimental *** results showed that the present numerical approach estimated various features of hydrodynamic cavitation well,including shedding processes and the length,shape,and collapse of cavitating *** the numerical analysis,three main stages were detected for the present cavitating flow,and the vorticity-cavitation interactions were investigated by the vorticity transport *** streak-like and tube-like cavitating(STLIC and TULIC)structures were introduced in the second stage,initiated by flow instability,and entirely governed by corresponding turbulent flow *** collapse of these cavitating structures is one of the primary sources of cavitation erosion on lower and upper *** results of the numerical erosion predictions were compared with those of the previous erosion tests on the Grenoble axisymmetric *** numerical performance was achieved in predicting the location and intensity of cavitation erosion.

关键词： Turbulent and cavitating structures cavitation erosion detached vortical flow hybrid RANS-LES turbulence modeling flow instability flow visualization

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Spatial analysis of public h.alth facilities in Riyadh Governorate,Saudi Arabia:a GIS-based study to assess geographic variations of service provision and accessibility

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Geo-Spatial Information Science 2016年第1期19卷 26-38页

作者： Shawky mansour Faculty of Arts Department of Geography and GISAlexandria UniversityEl ShatbyAlexandriaEgypt

Much attention has been given to address public h.alth policy in Saudi Arabia,particularly for the management,quality,and coverage ***,assessment of spatial patterns,distribution,and provision of public h.alth services has been *** paper analyzes the availability and accessibility of public h.alth facilities across Riyadh Governorate,Saudi Arabia at the subnational *** and attribute data of public h.alth facilities potentially have been analyzed using GIS to produce accurate measure of *** spatial pattern of service distribution was examined using average nearest *** from demand points(populations)to providers(facilities)were calculated for each district using near *** addition,the ratios of public h.alth facility to population were calculated to identify underserved and overserved *** findings clearly indicate that the spatial pattern of the distribution of public h.alth facilities was significantly clustered(p valueh Z-score of–*** districts within the central parts of the governorate were identified as having a higher density of facilities,while most of districts that are located in the marginal parts exhibit very low density of h.alth ***,there was a considerable variation in the average distance from district centroids to h.alth ***,less than half of the population(45.4%)living in 61 districts has access to public h.alth facility within less than 1-km *** contrast,the greatest increase in distances was observed for 6%of population living in 38 *** that live in such districts need to travel long distances for public h.alth *** output of this analysis can assist policy-makers and authorities of Riyadh Governorate in planning public h.alth delivery.

关键词： GIS public h.alth facilities accessibility availability Riyadh Governorate

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Properties and corrosion behavior of al based nanocomposite foams produced by the sintering-dissolution process

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International Journal of Minerals,Metallurgy and Materials 2018年第1期25卷 94-101页

作者： Mostafa Amirjan mansour Bozorg Metallurgy Division Department of Chemical and Materials EngineeringNiroo Research InstituteTehran ***Iran Faculty of Chemical&Materials Engineering Shahrood University of TechnologyShahrood ***Iran

The properties oral based nanocomposite metal foams and their corrosion behaviors were investigated in this study. For this, the composite metal foams with different relative densities （porosity） reinforced with.alumina nanoparticles were prepared using a powder me- tallurgy-based sintering-dissolution process （SDP） and NaC1 particles were used as space holders. Then, the effect of nanoparticle rein- forcement and different amounts of NaC1 space holders （corresponding porosity） on the microstructure, morphology, density, hardness, and electrochemical specifications of the samples were investigated. It was found that as the relative density increased from 60% to 70%, the wall thickness increased from about 200 to 300 pro, which led to a decrease in pore size. also, the addition of nanoparticle reinforcement and the increased relative density result in increasing metal foam hardness. Moreover, electrochemical test results indicated that increasing the A1203 content reduced the corrosion rate, but increasing the porosity enhanced it.

关键词： aluminum-alumina nanocomposite metal foam sintering-dissolution process corrosion behavior electrochemical impedance

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单面贴补修理后层合板的拉伸性能

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复合材料学报 2005年第3期22卷 140-144页

作者： ali al-mansour 程小全寇长河北京航空航天大学飞机设计研究所北京100083

对含孔损伤复合材料层合板单面贴补后进行拉伸试验研究。测量了层合板的应变分布、修理后层合板中心点的离面位移及拉伸强度等,考察了补片的厚度、大小等因素对修理效果的影响。结果显示,增加补片的厚度和直径能够提高母板的承拉能力,... 详细信息

对含孔损伤复合材料层合板单面贴补后进行拉伸试验研究。测量了层合板的应变分布、修理后层合板中心点的离面位移及拉伸强度等,考察了补片的厚度、大小等因素对修理效果的影响。结果显示,增加补片的厚度和直径能够提高母板的承拉能力,但是增加补片的厚度会导致层合板离面位移增大。对无侧边支持的单面贴补层合板进行计算分析时,必须考虑偏心载荷引起的弯矩的影响。在此基础上,采用分层损伤判据建立了三维有限元模型,对单面贴补层合板的破坏机理和拉伸强度进行了计算和分析。结果表明,修理后层合板的拉伸破坏是由补片或母板内与胶接面相邻的层间分层引起的;计算结果与试验结果一致。

关键词：层合板贴补单面修理双面修理拉伸强度

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Chemo- and regioselective hydroboration of Δ^(14,15) in certain cephalostatin analogue

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Chinese Chemical Letters 2008年第12期19卷 1391-1394页

作者： mansour Nawasreh Basic Sciences Department Faculty of Engineering TechnologyAI-Balqa Applied UniversityP.B.15008Marka11134 AmmanJordan

The symmetrical diketone Ⅱ, which can be synthesized in gram scale using a well established method, was used as a starting material to prepare the 11α-methoxy ketomethylene Ⅵ. This is in continuation of our study aiming at the synthesis of multihydroxylated cephalostatin analogues, as for example cephalostatin 1Ⅰ, a potent anti-tumor natural product. Compound Ⅵ underwent chemo- and regioselective hydroboration reaction at only one of △14.15 double bonds furnishing compound Ⅸ as a major product in a fair yield.

关键词： Cephalostatin 1 Diketone hydroboration of △^14,15 double bond Anti-cancer activity

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Deep Learning Based License Plate Number Recognition for Smart Cities

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Computers, Materials & Continua 2022年第1期70卷 2049-2064页

作者： T.Vetriselvi E.Laxmi Lydia Sachi Nandan Mohanty Eatedal alabdulkreem Shaha al-Otaibi Amal al-Rasheed Romany F.mansour Department of Computer Science and Engineering K.Ramakrishnan College of TechnologyTrichy620002India Computer Science and Engineering Vignan’s Institute of Information TechnologyVisakhapatnam530049India Department of Computer Science&Engineering Vardhaman College of Engineering(Autonomous)Hyderabad501218India Department of Informatics and Computing Singidunum UniversitySerbia Computer Science Department College of Computer and Information SciencesPrincess Nourah Bint Abdulrahman UniversityRiyadh11564Saudi Arabia Information Systems Department College of Computer and Information SciencesPrincess Nourah Bint Abdulrahman UniversityRiyadh11564Saudi Arabia Department of Mathematics Faculty of ScienceNew Valley UniversityEl-Kharga72511Egypt

Smart city-aspiring urban areas should have a number of necessary elements in place to achieve the intended *** controlling and management of traffic conditions,increased safety and surveillance,and enhanced incident avoidance and management should be top priorities in smart city *** the same time,Vehicle License Plate Number Recognition(VLPNR)has become a hot research topic,owing to several real-time applications like automated toll fee processing,traffic law enforcement,private space access control,and road traffic *** VLPNR is a computer vision-based technique which is employed in the recognition of automobiles based on vehicle number *** current research paper presents an effective Deep Learning(DL)-based VLPNR called DLVLPNR model to identify and recognize the alphanumeric characters present in license *** proposed model involves two main stages namely,license plate detection and Tesseract-based character *** detection of alphanumeric characters present in license plate takes place with the help of fast RCNN with Inception V2 ***,the characters in the detected number plate are extracted using Tesseract Optical Character Recognition(OCR)*** performance of DL-VLPNR model was tested in this paper using two benchmark databases,and the experimental outcome established the superior performance of the model compared to other methods.

关键词： Deep learning smart city tesseract computer vision vehicle license plate recognition

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Micro Gas Turbine Range Extender Performance Analysis Using Varying Intake Temperature

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Automotive Innovation 2020年第4期3卷 356-365页

作者： Raja Mazuir Raja Ahsan Shah mansour al Qubeissi Andrew McGordon Mark Amor‑Segan Paul Jennings Faculty of Engineering Environment and ComputingCoventry UniversityCoventry CV12JHUK Warwick Manufacturing Group University of WarwickCoventry CV47ALUK

A micro gas turbine(MGT)can potentially be an alternative power source to the conventional internal combustion engine as a range extender in hybrid electric *** integration of the MGT into a hybrid vehicle needs a new approach for technical validation requirements compared to the testing of an internal combustion *** attributes of the MGT are predicted to cause concerns for vehicle sub-system requirements such as high ambient temperature and start-stop *** paper describes the results from specially developed experimental techniques for testing the MGT in a typical automo-tive environment.A black box MGT was used in this study for performance investigation during hot and cold *** MGT was instrumented and fitted with automotive standard components to replicate typical vehicle operational *** intake air temperature was varied between 10 and 24°C.A significant reduction in the power output of the MGT was observed as the intake temperature was *** proposed case scenario caused a reduction in nitrogen oxide emis-sions in the range of 0.02−0.04 g/km because of the lower combustion temperature at high intake ***,hydrocarbon and carbon monoxide emissions have not shown a noticeable reduction during the power output *** experimental results have highlighted the potential issues of using the MGT at higher intake temperatures and suggest design change to take the effect of higher engine bay temperature into account.

关键词： Micro gas turbine hybrid vehicle Range extender Test characterization

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Real-time-guided bone regeneration around standardized critical size calvarial defects using bone marrow-derived mesenchymal stem cells and collagen membrane with and without using tricalcium phosphate: an in vivo microcomputed tomographic and histologic e

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International Journal of Oral Science 2016年第1期8卷 7-15页

作者： Khalid al-hezaimi Sundar Ramalingam mansour al-Askar Aws S ArRejaie Nasser Nooh Fawad Jawad Abdullah.aldahmash Muhammad Atteya Cun-Yu Wang Engineer A.B.Growth Factors and Bone Regeneration Research Chair and 3D Imaging Center College of DentistryKing Saud UniversityRiyadhSaudi Arabia Department of Periodontics and Community Dentistry College of DentistryKing Saud UniversityRiyadhSaudi Arabia Department of Oral and Maxillofacial Surgery College of DentistryKing Saud UniversityRiyadhSaudi Arabia Department of Substitutive Dental Sciences College of DentistryUniversity of DammamDammamSaudi Arabia Stem Cell Unit Department of AnatomyCollege of MedicineKing Saud UniversityRiyadh Division of Oral Biology and Medicine School of DentistryUniversity of California at Los AngelesLos AngelesUSA

The aim of the present real time in vivo micro-computed tomography （pCT） and histologic experiment was to assess the efficacy of guided bone regeneration （GBR） around standardized calvarial critical size defects （CSD） using bone marrow-derived mesenchymal stem cells （BMSCs）, and collagen membrane （CM） with and without tricalcium phosphate （TCP） graft material. In the calvaria of nine female Sprague-Dawley rats, full-thickness CSD （diameter 4.6 mm） were created under general anesthesia. Treatment-wise, rats were divided into three groups. In group 1, CSD was covered with a resorbable CM; in group 2, BMSCs were filled in CSD and covered with CM; and in group 3, TCP soaked in BMSCs was placed in CSD and covered with CM. all defects were closed using resorbable sutures. Bone volume and bone mineral density of newly formed bone （NFB） and remaining TCP particles and rate of new bone formation was determined at baseline, 2, 4, 6, and 10 weeks using in vivo pCT. At the lOth week, the rats were killed and calvarial segments were assessed histologically. The results showed that the hardness of NFB was similar to that of the native bone in groups I and 2 as compared to the NFB in group 3. Likewise, values for the modulus of elasticity were also significantly higher in group 3 compared to groups 1 and 2. This suggests that TCP when used in combination with BMSCs and without CM was unable to form bone of significant strength that could possibly provide mechanical ＂lock＂ between the natural bone and NFB. The use of BMSCs as adjuncts to conventional GBR initiated new bone formation as early as 2 weeks of treatment compared to when GBR is attempted without adiunct BMSC therapy.

关键词： bone marrow-derived mesenchymal stem collagen membrane critical size defect guided bone regeneration tricalciumphosphate

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NSAIDs for prevention of pancreatitis after endoscopic retrograde cholangiopancreatography:Ready for prime time?

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World Journal of Gastroenterology 2012年第30期18卷 3936-3937页

作者： mansour A Parsi Section for Therapeutic and Pancreatobiliary Endoscopy Digestive Disease InstituteCleveland ClinicClevelandOH 44195United States

Acute pancreatitis is the most common and the most fearful complication of endoscopic retrograde cholangiopancreatography (ERCP).Prevention of post-ERCP pancreatitis has therefore been of great interest to endoscopists performing ERCP *** far,only pancreatic duct stenting during ERCP and rectal administration of a non-steroidal anti-inflammatory drug (NSAID) prior to or immediately after ERCP have been consistently shown to be effective for prevention of post-ERCP *** commentary focuses on a short discussion about the rates,mechanisms,and risk factors for post-ERCP pancreatitis,and effective means for its prevention with emphasis on the use of NSAIDs including a recent clinical trial published in The New England Journal of Medicine by Elmunzer et al.

关键词： Endoscopic retrograde cholangiopancreatography Pancreatitis Post-endoscopic retrograde cholangiopancreatography pancreatitis Pancreatic stents Non-steroidal anti-inflammatory drugs

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Coexistence and fluctuations phenomena with Davidson-like potentials in quadrupoleoctupole deformed nuclei

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Communications in Theoretical Physics 2021年第3期73卷 105-118页

作者： M M hammad W h mansour E M El-Maghraby h A Motaweh Ayman A aly Faculty of Science Mathematics DepartmentDamanhour UniversityEgypt Faculty of Science Physics DepartmentDamanhour UniversityEgypt

The energy spectra of three types of two-dimensional potentials(we will call them‘Davidson-like potentials’(DLPs)),characterized by four minima separated by barriers,are *** predictions for spectra and wave functions are obtained by using the nine-point finite-difference *** these potentials,with the existence of a single configuration,a transition of spectra,as a function of barrier height,is covered from tunneling splitting modes to fluctuations phenomena,with equal peaks wave functions,crossing to the spectra of purely anharmonic oscillator potentials(AOPs).A different type of phase transition occurs when two(or more)configurations *** the change of the parameters,a transition of spectra is covered from coexistence phenomena of two distinct quantum tunneling modes to fluctuations phenomena,with unequal peaks wave functions,crossing to the spectra of purely *** DLPs,a particular application of the coherent quadropole-octupole model to describe energy bands with.alternating parity of the nuclei^(100)Mo,^(146,148)Nd,^(148,150)Sm,^(220)Ra,^(220,222)Rn,and^(220,222)Th is *** global parametrization of the model for the selected nuclei is achieved.

关键词： quantum phase transitions fluctuations phenomena coherent quadrupole-octupole motion model coexistence phenomena

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