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Fabrication of Dye Sensitized Solar Cell Based on Titanium Dioxide (Tio2)

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Advances in Materials Physics and Chemistry 2015年第9期5卷 361-367页

作者： ari A. mohammed Alan S. Said Ahmad Wafaa A. Azeez Department of Physics Faculty of Science University of Zakho Duhok Iraq

The Dye Sensitized Solar Cell (DSSC) plays an important role because of low material cost, ease of production and high conversion efficiency as compared to other thin-film solar cell technologies. The main objective is to create and find the best configuration of the solar cell based on materials that are inexpensive and highly efficient in solar energy conversion and subsequently test the efficiency of dye sensitized titanium dioxide solar cell. We begin the process with two glass plates coated with Fluorine tin oxide (FTo). Titanium dioxide is applied to the conductive side of one plate and the other plate is coated with graphite. A dye is adsorbed on to the Tio2 layer and then the plates are sandwiched together. A drop of iodide electrolyte is then added between the plates. The tests carried out indoors under a lamp emitting all wavelengths in the visible spectrum were not found to provide consistent data due to substantial heating of the cell. The outdoor tests carried out in natural sunlight exhibited steady voltage at much higher level. Future research will involve the incorporation of quantum dots instead of the organic dye as a sensitizer. Quantum dots have the advantages of providing tunable band gaps and the ability to absorb specific wavelength.

关键词： Transparent Conducting Glass Titanium Dioxide (TIo2) Nanoparticles organic Dyes Electrolyte

The Effect of Doped Indium on the Electrical and optical Properties of (Se0.7Te0.3)1−xInxThin Films

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Advances in Materials Physics and Chemistry 2015年第4期5卷 140-149页

作者： Muhaj Talib Abdullah Alan S. Said Ahmad ari A. mohammed Department of Physics Faculty of Science University of Zakho Duhok Iraq

In-doped (Se0.7Te0.3) thin films (In: 0, 0.05, and 0.08wt%) with thickness of (150 ± 25 nm) have been deposited on glass substrates by chemical vapor deposition by using selenium, tellurium and indium whose purity is (99.99%) compound alloy. The electrical and optical properties of the thin films were analyzed. The effects of In-doping concentration on the thermoelectric properties of the thin films were investigated by room-temperature measurement of the See beck coefficient and electrical resistivity. The thermoelectric power factor shows the best result at 0.05wt% in doping. The See beck coefficients are positive with increasing in doping concentration from 0 to 0.08wt%. And the thin films show p-type conduction. For optical properties, the transmission of all samples was approximated to 90%.

关键词： Selenium Tellurium Indium p-Type Fermi-Level

A Comparative Study of Ear Diseases in School Children from Lower versus Higher Socioeconomic Status

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International Journal of otolaryngology and Head & Neck Surgery 2021年第2期10卷 107-118页

作者： Yohanna Mairiga Takwoingi mohammed Bello Fufore Abubakar Umar Gabsari Emmanuel Musa Wuni ari Thimnu Isah Abdullahi Department of ENT City Hospital Birmingham UK Department of ENT Federal Medical Centre Yola Nigeria Department of ENT University of Maiduguri Teaching Hospital Maiduguri Nigeria

Background: Preventable otologic conditions have been found to be important health issues among paediatric age group. Poor socioeconomic status and inappropriate management services in developing countries lead to var... 详细信息

ong>Background:ong> Preventable otologic conditions have been found to be important health issues among paediatric age group. Poor socioeconomic status and inappropriate management services in developing countries lead to various complications despite the fact that most of these diseases are self-limiting. The aim of this study was to determine the prevalence and pattern of ear diseases in school children of high and low socioeconomic status in Yola, Nigeria. ong>Methods:ong> This study was conducted in March 2017 in two primary schools (private and public) in Yola among 6 - 8 years old pupils. Approval for the study was obtained from Federal Medical Centre, Yola and consent was obtained from the parents/guardians and the school authorities. Using a health questionnaire, a brief ENT history was obtained from children in years 1 and 2 of each school. otoscopic examination, audiometry and tympanometry were then carried out. Data collected was analysed using SPSS version 20. ong>Results:ong> one hundred and three children were studied. The age range was 6 - 8 with mean age of 6.8 ± 0.9 and 53 (51.5%) boys. Fifty-two (50.5%) were from public school (low socio-economic class) and 51 (49.5%) from private (high social class). Wax was the most common ear condition encountered affecting 37 (35.9%) children, and the number was similar in both groups. otitis media with effusion (oME) was encountered in seven children evenly split between the two groups showing a point incidence of 6.8%. There was hearing loss in 13 (12.6%) children, and this was also similar in the two groups. ong>Conclusion:ong> Wax impaction was the commonest otologic disease encountered. our study also showed a point incidence of 6.8% for oME, but there was no statistical difference between the two groups, and neither was there any statistically significant difference between the two groups in any of the other diseases encountered.

关键词： Children Glue-Ear Hearing Loss Social Status Wax

不同抛光方式对去除托槽后牙釉质表面影响的研究

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不同抛光方式对去除托槽后牙釉质表面影响的研究

作者： LABIB HAZAA mohammed GHALEB 中国医科大学

学位级别：硕士

目的:固定矫治结束时,需要去除托槽和牙齿表面的粘结剂以便恢复牙齿的美观和健康。去除粘结剂时,一方面要尽可能地去除干净以恢复牙面的光洁,预防牙菌斑滞留,另一方面更要防止损伤牙釉质。因此,选择合适的车针以及有效评估去除效果具有... 详细信息

目的:固定矫治结束时,需要去除托槽和牙齿表面的粘结剂以便恢复牙齿的美观和健康。去除粘结剂时,一方面要尽可能地去除干净以恢复牙面的光洁,预防牙菌斑滞留,另一方面更要防止损伤牙釉质。因此,选择合适的车针以及有效评估去除效果具有一定的临床意义。本研究旨在应用放大镜对应用不同种类车针去除粘结剂的效果进行评价,以期对今后临床相关操作有所启示。方法:从中国医科大学附属口腔医院门诊收集因正畸需要拔除的前磨牙60颗,随机分为3组,每组n=20。TC组(用碳化钨车针去除粘结树脂)、SD组(用软盘车针去除粘结树脂)、DB组(用金刚石车针去除粘结树脂)。将每组各分为两个亚组(每亚组n=10),肉眼组(NTC、NSD、NDB)在肉眼直视下操作;放大镜组(MTC、MSD、MDB)借助放大镜进行操作。使用Transbond XT正畸粘结剂粘接金属托槽,24小时后用去托槽钳去除托槽,评估牙面粘结剂残余指数(ari)。再分别使用不同的车针去除残余的粘结剂,以秒为单位记录去胶时间,最后均用矽粒子进行抛光。应用Mitutoyo SJ-210轮廓仪对每个亚组进行评估,以确定牙齿平均表面粗糙度(Ra),在扫描电子显微镜(SEM)下确定牙釉质损伤指数(EDI)并评分。评估在三个时间点进行:粘接前(T0)、去除粘结剂后(T1)、抛光后(T2)。结果:Kruskal-Wallis检验显示各研究组ari无统计学差异(P>0.05)。方差分析显示,与肉眼组相比,放大镜组去除粘结树脂所需的时间显著减少(P0.05),T1、T2时Ra均值差异有统计学意义(P0.05),其余各组间差异均有统计学意义(P0.05)。T0、T1、T2的表面粗糙度两两比较显示,NDB和MDB在T1时的Ra均值与T0、T2时比较,差异有统计学意义(P0.05)。而在NDB和MDB中,T0、T1、T2的表面粗糙度Ra平均值差异有统计学意义(P0.05)。结论:1.低速碳化钨车针与软盘车针相当,可作为金刚石车针的替代品。2.金刚石车针在肉眼直视下操作会对牙釉质造成严重的损伤,而借助放大镜进行操作可以减轻对牙釉质的损伤。3.矽粒子抛光步骤可以使肉眼直视下操作的牙齿表面更光滑。4.无论使用哪种类型的车针去除粘结剂,借助放大镜进行操作都更好。

关键词：正畸去托槽粘结剂残留抛光牙釉质

基于RANSE模型CFD预测E779A型螺旋桨空化及其在通用船体后的水动力性能

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哈尔滨工程大学学报（英文版） 2023年第2期22卷 273-283页

作者： mohammed Adnan Rizk Samir E.Belhenniche omar Imine omer Kemal Kinaci Faculty of Mechanical and Electrical Engineering Maritime Engineering DepartmentTishreen UniversityLattakiaSyria Naval Aero-Hydrodynamic Laboratory Marine Engineering DepartmentUSTO MBOran 31000Algeria Aeronautics and Propulsion Systems Laboratory Mechanical Engineering DepartmentUSTO MBOran 31000Algeria Faculty of Naval Architecture and ocean Engineering Istanbul Technical UniversityIstanbul 34469Turkey Department of Mechatronics Engineering Istanbul Technical UniversityIstanbul 34469Turkey Marine Cybernetics Advanced Vehicle Technologies(MARNETICS) ITU ARI TeknokentIstanbul 34349Turkey

Ship propulsion performance heavily depends on cavitation,increasing the recent interest in this field to lower ship *** research on the effects of cavitation is generally based on the open-water propeller performance but the interactions of the cavitating propeller with the ship hull significantly affect the propulsion performance of the *** this study,we first investigate the INSEAN E779A propeller by a RANSE-based CFD in open-water *** numerical implementation and the selected grid after sensitivity analysis partially succeeded in modeling the cavitating flow around the *** agreement was observed compared to experimental ***,using the open-water data as input,the propeller’s performance behind a full-scale ship was calculated under self-propulsion *** being an undesired incident,we found a rare condition in which cavitation enhances propulsion ***σ=1.5;the propeller rotation rate was lower,while the thrust and torque coefficients were higher.

关键词： Cavitation Marine propeller Propulsion efficiency Propeller-hull interaction INSEAN E779A

A Comparative Study of Ear Diseases in School Children from Lower versus Higher Socioeconomic Status

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