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Thermal performance of domed roof in air-conditioned spaces

Energy and Built Environment 2024年第2期5卷 270-287页

作者： Ibrahim Reda raouf n.abdelmessih Mohamed Steit Ehab M.Mina Mechanical Power Engineering Faculty of EngineeringAin Shams University1 El-Sarayat St.Cairo 11517Egypt Architectural Engineering Faculty of EngineeringAin Shams UniversityCairoEgypt

Due to their thermal performance,domed roofs are one of the passive solutions that affect energy consumption in *** thermal performance of domed roofs has been investigated in many naturally ventilated ***,few studies have discussed their performance in conditioned ***,this study introduces a computational comparison between domed and flat roofs to investigate their impact on thermal comfort inside a conditioned *** an earlier stage,field measurements were carried out inside a Bahraini mosque to acquire its indoor air conditions during the summer period of 2021,in addition to validating the computational *** findings of this study confirm that,under mechanical cooling conditions,the flat roof offers a lower indoor temperature than the domed roof by 0.4℃and 0.1℃for open and closed doors,***,the air velocity is lower by approximately 0.01 m/s for both door *** overall PMV values of the flat roof are also lower by 0.07 and 0.01,while the PPD values are lower by 0.20,and 0.34 for open and closed doors,*** on these small differences,it can be concluded that the thermal performance of both roofing systems behaves equally in conditioned ***,the air patterns are substantially different,the overall thermal performance is *** similarity drives building designers to rethink the thermal performance of the domed roofs in air-conditioned spaces with such a hot climate,regardless of their aesthetic and acoustical behaviour.

关键词： Thermal comfort Computational fluid dynamics(CFD) Predicted mean vote(PMV)and predicted percentage dissatisfied(PPD) Domed roof Flat roof

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SYnTHESIS AnD CHARACTERIZATIOn OF SCHIFF-BASE-COnTAInInG POLYAMIDES

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Chinese Journal of Polymer Science 2011年第2期29卷 149-155页

作者： Mousa Ghaemy Hossein Mighani raouf Alizadeh Department of Chemistry Mazandaran UniversityBabolsarIran

A series of new Schiff base polyamides（PAs） were synthesized by polycondensation of benzilbisthiosemicarbazone diamine（LH6） with different commercially available aliphatic and aromatic diacid chlorides. The monomer and all the PAs were characterized by FTIR,^1H-nMR,and elemental *** prepared polyamides showed inherent viscosities in the range of 0.30-0.36 dL/g in DMF at 25℃,indicating their moderate molecular *** PAs were completely soluble in aprotic polar solvents such as dimethylformamide（DMF）,n-methylpyrolidone（nMP）, tetrachloroethane（TCE）,dimthylsulfoxide（DMSO） and also in H_2SO_4 and partially soluble in THF,acetone and chloroform at room *** analysis showed that these PAs were practically amorphous and exhibited 10%weight loss above 220℃.

关键词： Polyamides Schiff base polymers Solubility Thermal stability

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Cancers in Eastern Libya: First results from Benghazi Medical Center

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World Journal of Gastroenterology 2014年第20期20卷 6293-6301页

作者： Zuhir Bodalal raouf Azzuz Riyad Bendardaf Department of Surgery Faculty of Medicine Libyan International Medical University Benghazi 15016 Libya Department of Oncology and Hematology Benghazi Medical Center Benghazi 24508 Libya Oncology Unit Department of Medicine University Hospital Sharjah Sharjah 72772 United Arab Emirates

AIM: To study the pattern of cancer incidence and determine the incidence rates in Eastern Libya (for the first time in a decade).

关键词： Colorectal cancer Cancer incidence Age-standardized rates Libya Mediterranean Epidemiology

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复合推进剂火箭发动机的热力计算

复合推进剂火箭发动机的热力计算

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作者： Belgacemi raouf 哈尔滨工程大学

学位级别：硕士

纳米级铝和水反应燃料由于在水下推进方面的应用而受到广泛关注。固体火箭发动机的热力计算是发动机设计工作中的基本计算之一,可为发动机的设计提供原始数据。本文针对某固体火箭发动机的设计需求,进行了金属/水反应发动机的性能计算... 详细信息

纳米级铝和水反应燃料由于在水下推进方面的应用而受到广泛关注。固体火箭发动机的热力计算是发动机设计工作中的基本计算之一,可为发动机的设计提供原始数据。本文针对某固体火箭发动机的设计需求,进行了金属/水反应发动机的性能计算和优化,具体研究内容包括：(1)以金属燃料为推进剂,建立了金属/水发动机热力计算的数学模型;(2)以最小吉布斯自由能法为基础,利用Visual FORTRAn语言开发工具编制了热力计算程序。利用热力计算程序计算了不同种类推进剂的能量特性,计算结果表明,纯铝粉燃料的能量特性高于其他配比条件下的铝基燃料;丁羟推进剂能量特性较差,不适合作水下超高速发动机的推进剂;GAP(叠氮化缩水甘油聚合物)粘合剂可明显改善铝基燃料的能量特性;在相同配比下,GAP粘合剂铝基燃料的能量特性高于丁羟粘合剂铝基燃料。针对铝冰推进剂,计算了不同Al/Al2O3配比下的能量特性。研究表明,当配比为80/20时比冲最大,最大比冲为2327.6n.s/kg,其相应的最优水燃比为0.9。

关键词：铝水燃烧反应铝冰推进剂水下推进空间推进发动机模拟

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Energy Conservation in Reliable Wireless Sensor networks

Energy Conservation in Reliable Wireless Sensor Networks

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2008 IEEE International Conference on Communications(ICC 2008)

作者： Fatma Bouabdallah nizar Bouabdallah raouf Boutaba InRIA-IRISA Campus de Beaulieu 35042RennesFrance School of Computer Science University of Waterloo

Energy-efficiency is one of the major concerns in wireless sensor networks since it impacts the network *** this paper,we investigate the relationship between sensor network performance,particularly its lifetime,and the number of active reporting nodes n by using both analytical and simulation *** first demonstrate that decreasing the number of reporting nodes increases the number of reports that need to be sent to the sink,in order to achieve the desired information reliability regarding the detected *** the other hand,we show that reducing the number of reporting nodes alleviates the energy wastage due to *** on this tradeoff,and as a main contribution,we derive the optimal number of reporting nodes n opt energy that minimizes the energy consumed to report reliably the occurrence of an *** other words,we prove that limiting the reporting tasks of a detected event to a small subset of sensor nodes （i.e.,n opt energy）,instead of using all the sensor nodes in the event area,enables significant energy conservation.

关键词： Energy conservation Wireless sensor networks Peer to peer computing Event detection Energy consumption Energy efficiency Media Access Protocol Routing protocols Communications Society Computer network reliability

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Fabrication of automatic switch for AC-DC completely automated measurement system at nIS

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Journal of Measurement Science and Instrumentation 2017年第1期8卷 27-31页

作者： M Helmy A raouf Rasha S M Ali 国家标准化研究所电量计量部埃及吉萨12211-136

A fast automatic AC-DC switch is designed and fabricated mainly by a microcontroller and three double poles single throw reed *** new switch is introduced to establish a fully automated system for AC-DC measurements through ACDC transfer standards for the first time at the national Institute for standards(n IS)in *** implemented circuit of theautomatic AC-DC switch and its protection are presented in *** AC voltage source is calibrated against DC voltagesource by using the demonstrated automatic switch as an application The calibrated voltage ranges are2V,6V,20V and60V as *** uncertainty budget is also evaluated for the calibrated values.

关键词： AC voltage measurement AC-DC transfer standard automatic switching system uncertainty

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Prediction of maximal heart rate percent during constant intensity efforts on trained subjects

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Open Journal of Internal Medicine 2012年第4期2卷 190-197页

作者： Chams Eddine Guinoubi Ammar nbigh Youssef Grira raouf Hammami Salma Abedelmalek Department of Physiology Faculty of Medicine Sousse Tunisia Higher Institute of Sports and Physical Education Kef Tunisia Research Laboratory “Sports Performance Optimization” National Center of Medicine and Science in Sports (CNMSS) Tunis Tunisia Research Unit High Institute of Sport and Physical Education University of Sfax Sfax Tunisia

The purpose of this study is to evaluate the relationship between %HRmax and %vVO2max at constant efforts made at different intensities. In randomized order, males healthy subjects (Age: 25 ± 7 years, Weight: 70 ± 11 kg, VO2max: 55 ± 8 ml·kg–1·min–1) were divided into two groups, a trained one with more than 3 training sessions per week (n = 10) a moderately trained one with 3 drives or less per week (n = 15). The difference between the two groups corresponds to a time to exhaustion above and below 40 min at 80% vVO2max. All subjects performed 5 tests with a gradual increase in speed of 1 km·h–1 every 2 min and 4 constant speed tests at 60%, 70%, 80% and 90% VO2max. All test were performed at the same time of day (i.e., 18:00 h). The results of this study showed that eighteen collective regressions including different independent variables were developed to predict %HRmax. The individual equations developed, have r values between 0.974 and 0.993 and Syx, between 1.2 and 1.9 ml·kg–1·min–1, they are more accurate than the collective equations (one equation for all subjects) with r values between 0.81 to 0.89 and Syx, between 4.1 and 5.3 ml·kg–1·min–1. In conclusion, this study has demonstrated that the model of predictions of %HRmax from %vVO2max in triangular tests were not appropriate for rectangular efforts. From the equations developed, we find that the time to exhaustion at 90% vVO2max is the best predictor of level of endurance then the time limit to 80% vVO2max.

关键词： Heart Rate Percent Treadmill Exercise Prediction Triangular Test

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Switching of K-Q intervalley trions fine structure and their dynamics in n-doped monolayer WS_(2)

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Opto-Electronic Advances 2023年第4期6卷 28-37页

作者： Jiajie Pei Xue Liu Andrés Granados delÁguila Di Bao Sheng Liu Mohamed-raouf Amara Weijie Zhao Feng Zhang Congya You Yongzhe Zhang Kenji Watanabe Takashi Taniguchi Han Zhang Qihua Xiong Collaborative Innovation Center for Optoelectronic Science and Technology International Collaborative Laboratory of 2D Materials for Optoelectronic Science and Technology of Ministry of Education and Guangdong ProvinceCollege of Optoelectronic EngineeringShenzhen UniversityShenzhen 518060China College of Materials Science and Engineering Fuzhou UniversityFuzhou 350108China Division of Physics and Applied Physics School of Physical and Mathematical SciencesNanyang Technological UniversitySingapore 637371Singapore College of Materials Science and Engineering Beijing University of TechnologyBeijing 100124China Research Center for Functional Materials International Center for Materials NanoarchitectonicsNational Institute for Materials ScienceTsukubaIbaraki 305-0044Japan State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics Tsinghua UniversityBeijing 100084China.

Monolayer group VI transition metal dichalcogenides(TMDs)have recently emerged as promising candidates for photonic and opto-valleytronic *** optoelectronic properties of these atomically-thin semiconducting crystals are strongly governed by the tightly bound electron-hole pairs such as excitons and trions(charged excitons).The anomalous spin and valley configurations at the conduction band edges in monolayer WS_(2)give rise to even more fascinating valley many-body *** we find that the indirect Q valley in the first Brillouin zone of monolayer WS_(2)plays a critical role in the formation of a new excitonic state,which has not been well *** employing a high-quality h-Bn encapsulated WS_(2)field-effect transistor,we are able to switch the electron concentration within K-Q valleys at conduction band ***,a distinct emission feature could be excited at the high electron doping *** feature has a competing population with the K valley trion,and experiences nonlinear power-law response and lifetime dynamics under *** findings open up a new avenue for the study of valley many-body physics and quantum optics in semiconducting 2D materials,as well as provide a promising way of valley manipulation for next-generation entangled photonic devices.

关键词： 2D materials WS_(2) charged excitons trions indirect Q-valley valleytronics

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