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Chinese Journal of Aeronautics 2021年第11期34卷 66-78页

作者： Zakaria MANSOURI riyadh belamadi ABYLSEN Science&Technology Rhone Alpes Grenoble 38000France Ecole Superieure de Technologies Industrielles(ESTI) Annaba 23000Algeria

In modern gas turbines,the High Pressure Turbine(HPT)is exposed to an extreme thermal environment due to the burned gases leaving the *** burned gases are characterized by flow and temperature distortions that effect the aerodynamics and heat transfer of the *** purpose of this paper is to investigate numerically the effect of the intensity of the swirling flow combined with the temperature non-uniformity‘‘Hot-Streak"(H-S)on the aerothermal performances of a HPT Nozzle Guide Vane(NGV).The investigations are conducted on the solid untwisted NGV annular cascade developed in NASA Lewis Research *** swirl intensities(|S_(n)|=0,0.1,0.25 and 0.5),two swirl orientations(positive and negative)and two hot-streaks(rounded and radial)at the NGV inlet are *** simulations are done by solving the Reynolds Averaged Navier-Stokes(RANS)equations using ANSYS-CFX *** results show that the H-S with swirl undergoes twisting following the orientation of the *** H-S twist is aggressive under positive swirl compared to the negative swirl *** inlet swirl generates a new secondary flow structure,so called Swirl Vortex(SV),which induces more aerodynamic *** aerodynamic efficiency under negative swirl found to be higher than that under positive *** maximum temperature on the vane surface is controlled by the radial transport of the SV towards the endwalls.

关键词： Aerodynamics Heat transfer Hot-Streak HP turbine NGV Swirl intensity

Neural network-based model for prediction of permanent deformation of unbound granular materials

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第6期11卷 1231-1242页

作者： Ali Alnedawi riyadh Al-Ameri Kali Prasad Nepal School of Engineering Deakin University

Several available mechanistic-empirical pavement design methods fail to include predictive model for permanent deformation(PD)of unbound granular materials(UGMs),which make these methods more *** addition,there are limited regression models capable of predicting the PD under multistress levels,and these models have regression limitations and generally fail to cover the complexity of UGM *** researches are focused on using new methods of computational intelligence systems to address the problems,such as artificial neural network(ANN).In this context,we aim to develop an artificial neural model to predict the PD of UGMs exposed to repeated *** repeated load triaxial tests(RLTTs)were conducted on base and subbase materials locally available in Victoria,Australia to investigate the PD properties of the tested materials and to prepare the database of the neural *** were prepared over different moisture contents and gradations to cover a wide testing *** ANN model consists of one input layer with five neurons,one hidden layer with twelve neurons,and one output layer with one *** five inputs were the number of load cycles,deviatoric stress,moisture content,coefficient of uniformity,and coefficient of *** sensitivity analysis showed that the most important indicator that impacts PD is the number of load cycles with influence factor of 41%.It shows that the ANN method is rapid and efficient to predict the PD,which could be implemented in the Austroads pavement design method.

关键词： Flexible pavement design Unbound granular materials Permanent deformation (PD) Repeated load triaxial test (RLTT) Prediction models Artificial neural network (ANN)

Effect of vertical stress rest period on deformation behaviour of unbound granular materials:Experimental and numerical investigations

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第1期11卷 172-180页

作者： Ali Alnedawi Kali Prasad Nepal riyadh Al-Ameri Mohanad Alabdullah School of Engineering Deakin University

Repeated load triaxial test is used to assess the deformation behaviour of unbound granular materials(UGMs) in flexible road pavements. Repeated load pulse characteristics(i.e. shape, loading period and rest period) are the stress configurations used in the experimental set-up to simulate the passing axle loads. Some researchers and standard testing protocols suggest a rest period of varying durations after a loading phase. A thorough review of existing literature and practises has revealed that there is no agreement about the effect of the rest period of vertical stress pulse on the deformation behaviour of the UGMs. Therefore,the main objective of this study is to investigate the effect of repeated stress rest period on the deformation behaviour of UGMs experimentally. Experiments are conducted, both with and without rest period, using basalt and granite crushed rocks from Victoria, Australia. Furthermore, in order to gain insight into the effect of the rest period, finite element modelling is also developed. Both the experimental and modelling results show that the rest period has a noticeable effect on both resilient and permanent deformation behaviours of UGMs. It is, therefore, recommended to take extra precautions while adopting a particular standard testing protocol and to supplement the results by additional tests with different loading configurations.

关键词： Flexible pavement Unbound granular materials(UGMs) Repeated load triaxial test Resilient modulus Permanent deformation Finite element modelling

Sub-1 GHz Network-Based Wireless Bridge-Monitoring System:Feature and Verification

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Structural Durability & Health Monitoring 2021年第4期15卷 281-297页

作者： Li Hui Faress Hraib Mohammad Rahman Miguel Vicente riyadh Hindi College of Engineering University of Louisiana at LafayetteLafayetteLA 70503USA ABNA Engineering St.LouisMO 63108USA Parks College of Engineering Aviation and TechnologySaint Louis UniversitySt.LouisMO 63103USA Department of Civil Engineering University of BurgosBurgos09001Spain

Traditional bridge monitoring systems often require wired connections between sensors,a data acquisition system,and data *** use of extension wires,conduits,and other costly accessories can dramatically increase the total cost of bridge *** the development of wireless technologies and the notable cost benefits,many researchers have been integrating wireless networks into bridge monitoring *** this study,a wireless bridge monitoring system has been developed based on the Sub-1 GHz *** main functional components of this system include sensors,wireless nodes,gateway and data *** nodes can convert analog signals obtained from the sensors to digital signals,then transmit the collected data to the gateway using the Sub1 GHz *** gateway receives and sorts data from different wireless nodes and then forwards these data to the data center *** collected data are processed in the data center using the data processing software developed in this *** order to validate the performance of the wireless system developed in this study,a steel girder bridge was monitored in the field during the concrete deck *** field results were also compared with the theoretical values obtained from finite element models to ensure the accuracy and reliability of the wireless *** results indicate that the wireless bridge monitoring system developed in this study is effective and *** Sub-1 GHz network can be a better solution for bridges with complicated site conditions because of the extended data transmission *** the power consumption can be controlled by using low-power consumption components,including the power control in software design can also dramatically reduce the system’s power consumption.

关键词： Bridge monitoring wireless network bridge deck construction exterior girder rotation

New shakedown criterion and permanent deformation properties of unbound granular materials

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Journal of Modern Transportation 2019年第2期27卷 108-119页

作者： Ali Alnedawi Kali Prasad Nepal riyadh Al-Ameri School of Engineering Deakin University

Unbound granular material specifications for road pavements in Australia are primarily based on physical material specification rather than mechanical characterisation. This simplified approach does not reflect the actual material performance under repeated dynamic traffic loads. There is a little information available on the influence of the local crushed rock properties and compacted layer properties on permanent deformation (PD). This study aims to characterise the local unbound granular materials in Victoria according to their PD behaviour under repeated loads and to develop a suitable shakedown criterion that could describe the PD of the tested materials to simplify the flexible pavement design. Repeated-load triaxial tests were conducted over several samples with a range of moisture contents, gradations, densities, and stress conditions. The laboratory test results showed that PD behaviour was influenced by several factors. In addition, the tested subbase-specified unbound granular materials reflect high PD resistance that is almost equivalent to basequality unbound granular materials. This may indicate that current requirements for the subbase-quality unbound granular materials are over-prescribe. Moreover, as the existing shakedown criterion was not applicable for the multi-stage repeated-load triaxial test and the local tested materials, a new shakedown criterion and new boundaries are proposed based on the PD behaviour. In the proposed criterion, the shakedown ranges are identified based on the curve angle of the PD vs. logarithm of the number of loading cycles, and this new criterion was validated using several materials from existing literature. The local tested base and subbase materials can be assigned as Range A when PD\1%, Range B when 1%\PD\3%, and Range C when PD[3%. The proposed criterion could provide a useful and quick approach to assess the PD of the unbound granular materials with both single and multistages of stresses.

关键词： Flexible pavement Unbound granular materials Repeated load triaxial test Permanent deformation Shakedown theory

Performance Evaluation of Real-Time Application for EDCA Function in IEEE 802.11e WLAN

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通讯和计算机（中英文版） 2012年第5期9卷 516-522页

作者： riyadh Qashi Faculty of Mathematics and Computer Engineering University of Leipzig 3ohannisgasse 26 04103 Leipzig Germany

Ethical Awareness： Do We Need to Teach Accounting Ethics？ The Case of Bahrain

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Journal of Modern Accounting and Auditing 2014年第3期10卷 270-296页

作者： riyadh Al-Abdullah University of Bahrain (UoB) Zallaq Kingdom of Bahrain

Based on the premise that ethics education leads to creation of the required （acceptable level of） ethical awareness, the general streamline of accounting ethics literature is strongly in favor of teaching adequate, efficient, and effective accounting ethics. This paper takes the position that this premise must be checked in an educational setting in which accounting ethics education lacks the characteristics of being adequate, efficient, and effective. Accordingly, a questionnaire with two parts was distributed to accounting students about to graduate from the University of Bahrain （UoB）. The first part is an exploratory investigation consisting of 21 variables/questions. The second part is an experimental investigation consisting of 13 hypothetical accounting cases representing various ethics violations. The general tendency by an accounting student based on the two parts indicates that he/she holds an acceptable level of ethical awareness, despite the fact that accounting education programs lack an adequate, efficient, and effective approach to teaching accounting ethics.

关键词： ethics accounting ethics education accounting student acts/behaviors ethical awareness goals/consequences

Seroconversion of Hepatitis B and Hepatitis C among Hemodialysis Patients,Baghdad,2015

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Journal of Health Science 2019年第1期7卷 23-28页

作者： riyadh Mraweh Ibrahim Bushra Jabbar Hashem Division of Total Quality Management and Institutional Development Directorate of Public Health. Ministry of Health Baghdad 10047 Republic of Iraq Training and Development Division Baghdad Al-rusafa directorate Republic of Iraq

Hepatitis C&B still the major problem in hemodialysis patients and the challenge continues in dialysis centers to prevent spread among patients and workers,the worldwide reported incidence of anti-HC antibody in dialysis center was range from 10.5%-24% yearly and the prevalence range 5-85%.Also,HBs-antigen had the same problem but with less incidence and *** the purpose of evaluating the seroprevalence and seroconversion of anti-HC antibody and HBs-antigen in Haemodialysis centers at Baghdad required action a retrospective incidence study from Nov.2015 to Jan.2016 on maintenance HD patients at hemodialysis centers in Al-kindi,Al-Karama and Baghdad *** data obtained from patients records of hospitals and we relied on laboratory test results for ELISA to determine the seroconversion and seroprevalence of anti-HC-antibody and *** study found the total prevalence of seropositive anti-HCV antibody in three centers were 251(28%),the seropositive patients of HBs-Ag were 14(2%)While the total seroconversion was 196(21%)anti-HCV antibody and for HBs-Ag 4(0.4%);so there was serious risk of nosocomial infection particularly for hepatitis C in the hemodialysis centers in Baghdad and AL-kindi while the problem with HBV was under control at same time The differences of seroconversion and seroprevalence of anti-HC antibody and HBs-antigen between the hospitals in the study may indicate to the level of infection control was applied in hospital.

关键词： Seroconversion seroprevalence hemodialysis hepatitis

Precipitation in Ni-35 at. pct Cr Alloy

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Journal of Materials Science & Technology 2002年第1期18卷 77-79页

作者： A.A.Al-Aql, M.S.Al-Salhi and M.I.AnsariPhysics Department, Faculty of Science, King Saud University, riyadh 11451, Saudi Arabia [ Manuscript received February 7, 2001, in revised form May 10, 2001] Dept. of Phys. Faculty of Sci. King Saud Univ. Riyadh 11451 Saudi Arabia

Precipitation study was carried out in Ni-35 at. pct Cr alloy by measuring electrical resistivity at different ageing temperatures and long ageing times. During ageing, it was observed that electrical resistivity initially rose with ageing time and then fell after very long ageing at a constant temperature. The initial increase in resistivity during ageing may be attributed to the formation of GP zones/Cr-rich precipitates at early stages by nucleation process and decrease in resistivity, and after attaining a maximum, is due to the growth of precipitate particles and subsequently by coarsening of these precipitates. The results of electrical resistivity measurements during ageing were confirmed by X-ray diffraction analysis indicating the formation of a Cr-rich phase and a Cr3Ni2 phase in the Ni matrix.

关键词： Precipitation Electrical resistivity Ageing Coarsening X-ray diffraction

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也门拜达省拉达区银屑病患者的生活质量评价

也门拜达省拉达区银屑病患者的生活质量评价

作者： Redhwan riyadh Haidar Al-battal 昆明医科大学

学位级别：硕士

[目的]本研究的目的是探讨居住在也门al-Bayda省的Rada’a区的银屑病患者的生活质量。[方法]纳入了 2021年10月至2022年10月期间在Al-Salam Health医疗医院皮肤病学中心就诊的银屑病患者及居住在同一地区的健康人各54例,共计108例。。... 详细信息

[目的]本研究的目的是探讨居住在也门al-Bayda省的Rada’a区的银屑病患者的生活质量。[方法]纳入了 2021年10月至2022年10月期间在Al-Salam Health医疗医院皮肤病学中心就诊的银屑病患者及居住在同一地区的健康人各54例,共计108例。。银屑病组是在Al-Salam Health医疗医院的皮肤病学中心确诊为银屑病的患者,对照组是未患银屑病或其他慢性疾病的健康人。使用阿拉伯语的世界卫生组织生活质量评估量表（Whool-Bref）、焦虑自评量表（Gad-7）和抑郁自评量表（PHQ-9）评估参与者的个人生活质量及焦虑、抑郁状态。[结果]我们的研究发现银屑病患者的生活质量评分低于健康人群（78.20±18.81 vs 93.33±15.00,P＜0.05）。银屑病患者的焦虑自评量表评分高于健康人群（11.17±4.3 vs 9.6±3.06,P＜0.05）。银屑病患者抑郁自评量表评分高于健康人群（18.98±6.45 vs 13.51 ±5.71,P＜0.05）银屑病患者的焦虑评分与生活质量评分之间存在负相关（相关系数=0.002,P＜0.05）,其抑郁评分与生活质量评分之间存在负相关（相关系数=0.453,P＜0.05）。抑郁对生活质量产生的负面影响较焦虑更多。人口特征对生活质量没有统计学意义。女性比男性更容易焦虑和抑郁（P＜0.05）。[结论]该研究表明了银屑病患者较健康人群的生活质量更差,焦虑、抑郁状态更严重。所以,对银屑病患者的生活质量评估和焦虑、抑郁评估是必要的,因为早期诊断是有效治疗的第一步。这将有助于改善银屑病患者的整体健康状况,并有助于心理治疗和皮肤病学的整合。

关键词：银屑病生活质量焦虑抑郁战争