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CFD Simulation of Fixed and Variable Pitch Vertical Axis Tidal Turbine

Journal of Marine Science and Application 2013年第2期12卷 185-192页

作者： Qihu Sheng Syed Shah Khalid Zhimin Xiong Zhimin Xiong ghazala Sahib Liang Zhang Deep Water Engineering Research Center Harbin Engineering University Harbin 150001 China Chinese Academy of Agricultural Mechanization Sciences Huhhot Branch Huhhot China Department of Statistics Shaheed Benazir Bhutto Women University Peshawar 25000 Pakistan

In this paper, hydrodynamic analysis of vertical axis tidal turbine （both fixed pitch ＆ variable pitch） is numerically analyzed. Two-dimensional numerical modeling ＆ simulation of the unsteady flow through the blades of the turbine is performed using ANSYS CFX, hereafter CFX, which is based on a Reynolds-Averaged Navier-Stokes （RANS） model. A transient simulation is done for fixed pitch and variable pitch vertical axis tidal turbine using a Shear Stress Transport turbulence （SST） scheme. Main hydrodynamic parameters like torque T, combined moment CM, coefficients of performance Cp and coefficient of torque Cr, etc. are investigated. The modeling and meshing of turbine rotor is performed in ICEM-CFD. Moreover, the difference in meshing schemes between fixed pitch and variable pitch is also mentioned. Mesh motion option is employed for variable pitch turbine. This article is one part of the ongoing research on tm＇bine design and developments. The numerical simulation results are validated with well reputed analytical results performed by Edinburgh Design Ltd. The article concludes with a parametric study of turbine performance, comparison between fixed and variable pitch operation for a four-bladed turbine. It is found that for variable pitch we get maximum Ce and peak power at smaller revolution per minute N and tip sped ratio 2.

关键词： vertical axis turbine tidal energy fixed pitch variable pitch

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Gamma-Ray Spectrometry and Induced Polarization Studies for El Atshan-II Uranium Prospect Area, Central Eastern Desert, Egypt

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Geomaterials 2014年第3期4卷 92-104页

作者： Assran S. M. Assran Ragaa A. M. Elsayed Hosni H. ghazala Hussein F. Abdelsalam Mansoura University Mansoura Egypt Nuclear Materials Authority Cairo Egypt

Gamma-ray spectrometry and induced polarization (IP) studies were carried out to determine the radioactive anomalous zones and to follow their lateral and vertical extensions in El Atshan-II uranium prospect area, central Eastern Desert, Egypt. This area and its surroundings are covered by different Precambrian basement rocks, which intruded by younger bostonite rock, andesite dykes and carbonate veins. Data of the gamma-ray spectrometry have been analyzed qualitatively and quantitatively by applying specific interpretation techniques. These data revealed a wide radioactivity range oscillating from 15.0 to 2362.0 Ur, 0.5 to 307.2 ppm, 0.1 to 55.1 ppm and 0.3 to 22.0% for the total count (Tc), equivalent uranium (eU), equivalent thorium (eTh) and potassium (K), respectively. The constructed radioelement concentration maps and eU-composite image of the study area showed that the anomalously high radioactivity levels are mainly associated with outcrops of the bostonite rock. The induced polarization data were mathematically inverted to produce the true resistivity and chargeability values of cross-sections below the surveyed lines traverse in the area. The resistivity values are varied both vertically and horizontally from 7.83 to more than 1042.0 ohm·m, while the chargeability values are ranged from 0.195 to more than 204.0 mV/V, suggesting variation of the rocks facies and mineralizations. Integration of the resistivity and chargeability data indicates the presence of some mineralized zones, mainly associated with the bostonite rock, with depths varied from the near-surface to more than 70 m. Therefore, a core drilling is recommended at some stations along three selected profiles to a depth of 70 - 100 m to test the depth, structural model and grade of mineralization in the area.

关键词： Gamma-Ray Uranium Thorium Induced Polarization Resistivity Chargeability

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Determination of Organochlorine and Nitrogen Containing Pesticide Residues in Water,Sediments and Fish Samples by Reverse Phase High Performance Liquid Chromatograph

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Agricultural Science & Technology 2009年第5期10卷 9-12页

作者： Shahid Mahboob ghazala S.Sultana Muhammad Rafique Asi S.Nadeem A.S.Chaudhry GC大学动物学系巴基斯坦费萨拉巴德38000 农业与生物核研究所巴基斯坦费萨拉巴德38000 纽卡斯尔大学食品和农村发展(SA-FRD)农学院

With high performance liquid chromatography, the concentrations of α-endosulfan, DDE, parathion methyl, isoproturon, atrazine, carbaryl and carbofuran were determined in farmed raised fish Labeo rohita of two weight groups. All these pesticide residues were detected in fish meat samples. All these pesticide residues except isoproturon were identified in soil sediments, whereas all these pesticide residues except isoproturon, carbaryl and DDE were also present in water samples. DDT, heptachlor, β-endosulfan, chlorpyrifos, dimethoate, captan, cypermethrin, chlorobromuron and chlorotoluron were absent in all samples of water, sediments and fish flesh. The pesticide residues levels were in order of parathion methyl 〉 DDE 〉 carbofuran 〉 atrazine 〉 α-endosulfan 〉 isoproturan 〉 carbaryl. The concentrations of pesticides were higher in fish weighing 800 -1 300 g than in those weighing 250 -750 g. The DDE was remained highest in sediments, while that was not detected in water samples. The pesticides （endosulfan, parathion methyl, atrazine and carbofuran） had crossed their MRL values （0.001 μg/g） in water samples.

关键词： Pesticrde residues Organochlorine Nitrogen containing pesticides Reverse phase Chromatograph

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Attitudes towards child restrains and seat belts usage in the learned population of Karachi,Pakistan

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World Journal of Emergency Medicine 2014年第3期5卷 218-223页

作者： Emaduddin Siddiqui Kiran Ejaz Shahan Waheed ghazala Irfan Kazi Munawar Khursheed Emergency Medicine Department Aga Khan University Hospital

BACKGROUND:Motor vehicles crashes(MVCs) are the leading cause of injury related morbidity and mortality in developed countries. Recent evidence proves that properly used child seat belts can dramatically reduce the risk of severe and life-threatening injury from MVCs. There are rarities of thought and inspiration regarding the use of child seat belts in our society and region,therefore we lack of data regarding factors and paucity of usage of child seat belts in motor vehicles. This study aimed to assess the knowledge and attitudes of child seat belt usage among the educated population in Karachi,***:Altogether 304 employees were investigated. They were employees of Aga Khan University who were using their cars and having children younger than 10 years old. A cross sectional observational study was designed,and a 36-item questionnaire in English was used to collect data on participants' demographic details,designation,educational level,economic status,validity of driving license,number of children and cars,availability of adult seat belts and child seat belts along with their functionality,awareness,knowledge and attitude toward its use,and reason of not using these devices. SPSS version 20 for Windows was used to analyze the data and the Chi-square test was ***:Totally 290 participants were recruited with a response rate of 72%(212). Of 212 participants,126(59%) were male. 154(72.6%) participants had valid driver licenses,and 154(72.6%) had adult seat belts in their vehicles. Only 32(15%) reported regular use of adult seat belts. Although 168(79.2%) participants had some knowledge about child restrains(CRs),only 65(22%) had CRs in their cars. Eighty-two(38.7%) participants got the knowledge about CRs and seat belts from media. Mothers were more concerned about the use of CRs than fathers. Only 14(6.6%) parents were found to use both adult and child seat belts all the time. Of the 157 parents who did not us use CRs,42 considered unnecessary,35

关键词： Child restrains Motor vehicles crash Injury prevention Pakistan

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培养角膜缘上皮移植后穿透性角膜移植术的早期结果

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美国医学会眼科杂志（中文版） 2005年第4期17卷 202-207,234页

作者： Virender S. Sangwan Himanshu P. Matalia Geeta K. Vemuganti ghazala Ifihekar Anees Fatima Shashi Singh, Gullapalli N. Rao 董白霞（译）马景学（校） Sudhakar and Sreekanth Ravi Stem Cell Biology Laboratory Hyderabad India. Cornea and Anterior Segment Service Hyderabad India. Ophthalmic Pathology Laaoratory Hyderabad India. LV Prasad Eye Institute and Center for Cellular and Molecular Biology Hyderabad India 不详

目的：描述曾行培养角膜缘上皮移植的患者再行穿透性角膜移植（PKP）的早期结果。方法：对因化学烧伤造成角膜缘干细胞缺乏而行培养的角膜缘上皮移植后又进行穿透性角膜移植术的患者有关人口统计学、原发病因、角膜缘移植类型、眼表稳... 详细信息

目的：描述曾行培养角膜缘上皮移植的患者再行穿透性角膜移植（PKP）的早期结果。方法：对因化学烧伤造成角膜缘干细胞缺乏而行培养的角膜缘上皮移植后又进行穿透性角膜移植术的患者有关人口统计学、原发病因、角膜缘移植类型、眼表稳定性、视力、移植片透明度和并发症方面的资料进行回顾和复习。对受体角膜片组织病理学特征进行研究，重点观察上皮状态。结果：在患有角膜缘干细胞缺乏而进行培养的角膜缘上皮移植术的125例患者中，15例接受了穿透性角膜移植术（PKP）。角膜缘上皮移植术后（自体移植组n=11，同种异体移植组n=4）平均间隔时间为7个月（范围2—12个月）。同种异体移植组的4例患者均接受了免疫抑制疗法。15只眼中14只眼（93％）获得了含有稳定的角膜上皮的健全的角膜植片。15只眼中14只眼术前最佳矫正视力低于20／200。PKP后平均随访8．3±5．0个月，8只眼最佳矫正视力高于20／60，5只眼最佳矫正视力20／200至20／60。2只眼低于20／200。15只眼中3只眼发生异体角膜植片的排斥反应但被成功治疗。1只眼发生植片排斥的同时发生了青光眼。同种异体角膜缘上皮移植无一例显示排斥表现。结论：培养的角膜缘上皮移植后，在形成稳定的眼表后行PKP的早期结果是良好的。为了避免排斥反应，培养的同种异体角膜缘上皮移植者行充分的免疫抑制治疗是必需的。角膜同种异体移植能够单独排斥同种异体角膜缘移植物。

关键词：角膜缘上皮移植术穿透性角膜移植术移植后培养早期角膜缘干细胞缺乏同种异体移植免疫抑制治疗组织病理学特征排斥反应

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