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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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Numerical study on cavitation in a globe control valve with different numbers of anti-cavitation trims

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Journal of Central South University 2018年第11期25卷 2677-2687页

作者： Hamidreza YAGHOUBI Seyed Amir Hossein MADANI mansour alizadeh Department of Mechanical Engineering Iran University of Science and TechnologyTehran 16846-13114Iran

Cavitation is a destructive phenomenon in control *** order to delay cavitation,a multi-series of perforated cylindrical plates,called trims,are ***,the effects of orifice diameter and different types of trims have been *** this study,by numerical analysis,a globe control valve was investigated by employing four different cases(without trim,with one trim,with two and three trims)and the impact of the number of these trims on the intensity,formation region and the initiation point of cavitation was *** was found that the addition of one stage or two stages of trims reduces the intensity and delays the onset of cavitation,relative to the valve without ***,no significant differences in terms of intensity and initiation point of cavitation were observed in the cases where two or three trims were ***,due to the high cost of producing the trims,and the severe drop in flow coefficient,it is not economically and technically justified to increase the number of trims to more than three.

关键词： numerical analysis anti-cavitation trim globe control valve

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Performance investigation of solar thermal collector with auxiliary heater for space heating

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Journal of Central South University 2021年第11期28卷 3466-3476页

作者： Hassan BIGLARIAN Mohammad Mazidi SHARFABADI mansour alizadeh Hossein GHARAEI Department of Energy Research Institute of Petroleum Industry(RIPI)TehranIran School of Mechanical Engineering Iran University of Science and Technology(IUST)TehranIran School of Mechanical Engineering College of EngineeringUniversity of TehranTehranIran

In this paper,the performance of a solar thermal system with a focus on space heating was investigated.A 70 m^(2) detached house was considered in the weather conditions of the city of Tehran,Iran.A thermosyphon solar water heater with a flat plate collector combined with an auxiliary electrical heater supplies the heating demand of the *** proposed system was modeled and analyzed using TRNSYS *** this regard,the TRNBuild module was employed for the building load *** model has been simulated for one year of *** effects of the solar collector’s surface area and storage volume were *** results show that for a solar collector with a 15 m^(2) surface area,the solar fraction is 0.29 in January,during which the solar radiation is the *** solar collectors of10 m^(2) and 5 m^(2) surface areas,the solar fraction falls to 0.23 and 0.14,respectively in ***,two cases of 150 L and 300 L storage tanks are taken into ***,it is found that using a 15 m^(2) solar collector and a 150 L storage tank can appropriately provide the building’ s heating demand taking the thermal performance and economic aspects into consideration.

关键词： space heating solar water heater thermosiphon solar collector TRNSYS software

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MARIE:One-Stage Object Detection Mechanism for Real-Time Identifying of Firearms

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Computer Modeling in Engineering & Sciences 2025年第1期142卷 279-298页

作者： Diana Abi-Nader Hassan Harb Ali Jaber Ali mansour Christophe Osswald Nour Mostafa Chamseddine Zaki Computer Science Department Faculty of SciencesLebanese UniversityBeirut146404Lebanon College of Engineering and Technology American University of the Middle EastEgaila54200Kuwait Lab-STICC CNRS UMR 6285ENSTA-BretagneBrest29200France

Security and safety remain paramount concerns for both governments and individuals *** today’s context,the frequency of crimes and terrorist attacks is alarmingly increasing,becoming increasingly intolerable to ***,there is a pressing need for swift identification of potential threats to preemptively alert law enforcement and security forces,thereby preventing potential attacks or violent *** advancements in big data analytics and deep learning have significantly enhanced the capabilities of computer vision in object detection,particularly in identifying *** paper introduces a novel automatic firearm detection surveillance system,utilizing a one-stage detection approach named MARIE(Mechanism for Realtime Identification of Firearms).MARIE incorporates the Single Shot Multibox Detector(SSD)model,which has been specifically optimized to balance the speed-accuracy trade-off critical in firearm detection *** SSD model was further refined by integrating MobileNetV2 and InceptionV2 architectures for superior feature extraction *** experimental results demonstrate that this modified SSD configuration provides highly satisfactory performance,surpassing existing methods trained on the same dataset in terms of the critical speedaccuracy *** these innovations,MARIE sets a new standard in surveillance technology,offering a robust solution to enhance public safety effectively.

关键词： Firearm and gun detection single shot multi-box detector deep learning one-stage detector MobileNet inception convolutional neural network

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Nano-Enhanced Dairy Scum Biodiesel Blends:Unleashing the Power of Aluminium Oxide for Sustainable and Efficient Engine Performance

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Journal of Thermal Science 2025年第1期34卷 283-302页

作者： Veeranna MODI Prasad B.RAMPURE Sunil Kumar SHETTY Madeva NAGARAL Channa Keshava NAIK N Johar MGM Muhammad Irsyad ABDULLAH Abdullah I.AL-mansour Shamshad ALAM KLE College of Engineering and Technology ChikodiVisvesvaraya Technological University Nitte (Deemed to be University) NMAM Institute of Technology (NMAMIT)Department of Mechanical Engineering Aircraft Research and Design Centre HAL Department of Mechanical Engineering BGS College of Engineering and TechnologyBengaluruAffiliated to Visvesvaraya Technological University Management and Science University Department of Civil Engineering College of EngineeringKing Saud University

This study investigates the effect of aluminium oxide nanoparticlesaddition to biodiesel blends made from dairy milk scum on performance and combustion characteristics of the diesel *** dispersion of Al2O3nanoparticles in B20 blends at different concentrations was done with the help of *** number of blends were prepared for the *** Machine learning algorithms(Random Forest（RF）and CatBoost) was used for the *** results show that in comparison to biodiesel blends without nanoparticles,the kinematic viscosity and density is higher for fuel blends with *** these Fuel blends have higher calorific *** blends exhibited reduced Brake Specific Fuel Consumption（BSFC） of2.85% than the blends without nano particles(Dairy Scum Methyl Ester Biodiesel 20%+Neat Diesel 80%（in volume）,DSMEB20),57.14% less CO,40.8% less hydrocarbon,and increased NOxemissions compared to conventional diesel,contributing to the development of environmentally friendly and renewable biofuel blends with *** B20NP30 is the optimal blend for performance and emission *** study concludes with findings on enhanced Brake Thermal Efficiency（BTE） of 26.29% in 3×10-5（in volume） Al2O3nanoparticle-blended DSME B20 and other DSME B20 fuel blends,emphasizing the importance of optimal nanoparticle *** correlation matrix shows how engine load,efficiency measures（BTE,BSFC）,and emissions（CO,CO2,NOx,Smoke） are connected in complex *** results help us understand the complicated dynamics of engine performance and emission characteristics ***'s diagram for BTE and BSFC shows that CatBoost-based BTE models perform superior to RF-based models during the training as well as testing *** results were obtained for CO and CO2emission results.

关键词： Al2O3 concentration CI engine Dairy Scum Methyl Ester Biodiesel

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Distinct element modelling of fracture plan control in continuum and jointed rock mass in presplitting method of surface mining

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International Journal of Mining Science and Technology 2014年第6期24卷 871-881页

作者： Sharafisafa mansour Aliabadian Zeinab alizadeh Rezvan Mortazavi Ali Department of Mining Metallurgy and Petroleum Engineering Amirkabir University of Technology Department of Mining Engineering Sahand University of Technology

Controlled blasting techniques are used to control overbreak and to aid in the stability of the remaining rock formation. Presplitting is one of the most common methods which is used in many open pit mining and surface blast design. The purpose of presplitting is to form a fracture plane across which the radial cracks from the production blast cannot travel. The purpose of this study is to investigate of effect of presplitting on the generation of a smooth wall in continuum and jointed rock mass. The 2D distinct element code was used to simulate the presplitting in a rock slope. The blast load history as a function of time was applied to the inner wall of each blasthole. Important parameters that were considered in the analysis were stress tensor and fracturing pattern. The blast loading magnitude and blasthole spacing and jointing pattern were found to be very significant in the final results.

关键词： Controlled blasting Presplitting method Continuum and jointed rock mass Distinct element modelling

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Computational fluid dynamics(CFD) simulation of effect of baffles on separation in mixer settler

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International Journal of Mining Science and Technology 2012年第5期22卷 703-706页

作者： Mohsen Ostad Shabani Ali Mazahery Mehdi alizadeh Ali Asghar Tofigh Mohammad Reza Rahimipour mansour Razavi Alireza Kolahi Materials and Energy Research Center(MERC) TehranIran

The main ideas in the development of the solvent extraction mixer settler focused on achieving clean phase separation,minimizing the loss of the reagents and decreasing the surface area of the *** role of baffles in a mechanically agitated vessel is to ensure even distribution,reduce settler turbulence,promote the stability of power drawn by the impeller and to prevent swirling and vortexing of liquid,thus,greatly improving the mixing of *** insertion of the appropriate number of baffles clearly improves the extent of liquid ***,excessive baffling would interrupt liquid mixing and lengthen the mixing *** fluid dynamics(CFD) provides a tool for determining detailed information on fluid flow(hydrodynamics) which is necessary for modeling subprocesses in mixer settler.A total of 54 final CFD runs were carried out representing different combinations of variables like number of baffles,density and impeller *** data shows that amount of separation increases with increasing baffles number and decreasing impeller speed.

关键词： Mixer settler Computational fluid dynamics Liquid-liquid Efficiency

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Spatial analysis of public health 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 health policy in Saudi Arabia,particularly for the management,quality,and coverage ***,assessment of spatial patterns,distribution,and provision of public health services has been *** paper analyzes the availability and accessibility of public health facilities across Riyadh Governorate,Saudi Arabia at the subnational *** and attribute data of public health 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 health facility to population were calculated to identify underserved and overserved *** findings clearly indicate that the spatial pattern of the distribution of public health facilities was significantly clustered(p value<0.001)with 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 health ***,there was a considerable variation in the average distance from district centroids to health ***,less than half of the population(45.4%)living in 61 districts has access to public health 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 health *** output of this analysis can assist policy-makers and authorities of Riyadh Governorate in planning public health delivery.

关键词： GIS public health 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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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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