检索结果-南通市图书馆

Mechanical characterization of cp-Ti produced by investment casting

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2011年第8期21卷 1735-1740页

作者： Khaled M.IBRAHIM mansour mhaede Lothar WAGNER Central Metallurgical R&D Institute(CMRDI) Institue of Materials Science and Engineering TU-Clausthal

The influence of hot swaging（SW） and annealing treatment on microstructure and mechanical properties of commercially pure titanium produced by investment casting was *** as-cast samples showed a typical microstructure consisting of a variety of α-morphologies,while the hot swaged samples exhibited a kinked lamellar *** at 500 °C did not significantly change this microstructure while annealing at 700 and 870 °C led to recrystallization and formation of equiaxed *** cast bars exhibited a typical hard α-layer in near-surface regions with a maximum depth and maximum hardness of 720 μm and HV0.5 660,*** to SW,the tensile strength of the as-cast material drastically increased from 605 MPa to 895 *** at 500 °C decreased the tensile strength slightly from 895 to 865 MPa while annealing at 700 °C led to a further pronounced drop in tensile strength from 865 to 710 *** additional decrease in tensile strength was noticed with increasing the annealing temperature from 700 to 870 °*** true fracture strain of the as-cast and hot swaged samples was in the range of 0.05 to 0.12,while the annealed samples showed values in the range of 0.25 to *** addition,the as-cast and hot swaged samples revealed a brittle cleavage fracture ***,the annealed samples showed a transgranular ductile fracture with formation of dimples.

关键词： pure titanium investment casting swaging thermo-mechanical processing mechanical properties

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

在线全文

学校读者我要写书评

暂无评论

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

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

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal Science 2025年第1期 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：

Numerical prediction of hydrodynamic cavitating flow structures and their corresponding erosion

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

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

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

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

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

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

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

在线全文

学校读者我要写书评

暂无评论

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

Quick Responses of Canadian Social Scientists to COVID-19:A Case Study of the 2020 Federal COVID-19-Specific Grant Recipients

在线全文

学校读者我要写书评

暂无评论

International Journal of Disaster Risk Science 2022年第4期13卷 636-649页

作者： Haorui Wu Adele mansour Canada Research Chair in Resilience School of Social WorkFaculty of HealthDalhousie UniversityHalifaxNS B3H 4R2Canada School of Communication Science and Disorders Faculty of HealthDalhousie UniversityHalifaxNS B3H 4R2Canada

COVID-19 prompted an abundance of independent and collaborative quick response disaster research(QRDR)initiatives *** 2020 federal COVID-19-driven granting opportunities initiated the first official QRDR effort in Canadian history,engaging social scientists to rapidly address the pandemic-related societal *** study aims to portray the landscape of this nascent social science QRDR workforce through the first round of federal COVID-19-specific grant recipients.A case study approach was employed to analyze 337 social science projects with 1119 associated researchers,examining the demographic structure of these COVID-19-driven social science researchers and their research projects'***,the findings are presented through the following two streams:(1)From a researcher perspective,this case study describes researcher typology,geographic location,primary discipline,and educational background,highlighting the diverse characteristics of social sciences researchers,and uneven research development across Canada.(2)From a research project perspective,this case study identifies and synthesizes research project subjects,themes,collaborations,and Canadian distinctions,emphasizing the need for galvanizing cooperation and focusing on uniquely Canadian *** case study illustrates challenges associated with data curation that pose barriers to developing a nuanced understanding of the Canadian social science community COVID-19 research ***,the case study develops three recommendations to improve QRDR development in Canada:promoting information transparency,dissemination,and updates;improving hazards and disaster research workforce evaluation;and enhancing multi-stakeholder cooperation.

关键词： Canadian federal granting agencies COVID-19 Quick response disaster research Research projects Research workforce Social sciences

Development of A Three-Dimensional Guidance System for Long-Range Maneuvering of A Miniature Autonomous Underwater Vehicle

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2014年第6期28卷 843-856页

作者： mansour ATAEI Aghil YOUSEFI-KOMA Center of Advanced Systems & Technologies Faculty of Mechanical EngineeringCollege of Engineering University of Tehran

The present paper introduces a three-dimensional guidance system developed for a miniature Autonomous Underwater Vehicle（AUV）. The guidance system determines the best trajectory for the vehicle based on target behavior and vehicle capabilities. The dynamic model of this novel AUV is derived based on its special characteristics such as the horizontal posture and the independent diving mechanism. To design the guidance strategy, the main idea is to select the desired depth, presumed proportional to the horizontal distance of the AUV and the target. By connecting the two with a straight line, this strategy helps the AUV move in a trajectory sufficiently close to this line. The adjacency of the trajectory to the line leads to reasonably short travelling distances and avoids unsafe areas. Autopilots are designed using sliding mode controller. Two different engagement geometries are considered to evaluate the strategy＇s performance： stationary target and moving target. The simulation results show that the strategy can provide sufficiently fast and smooth trajectories in both target situations.

关键词： Autonomous Underwater Vehicle(AUV) Three-Dimensional(3D) guidance system Line-of-Sight(LOS) strategy autopilot sliding mode controller