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Control of Doubly Fed Induction Generator Supplied via matrix Converter for Wind Energy Conversion System

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International Journal of modern Nonlinear Theory and Application 2014年第3期3卷 98-112页

作者： zakaria Kara Kamel Barra Electrical Engineering Larbi Ben M’hidi University Oum El Bouaghi Algeria

The present paper deals with the modeling and control of Wind Energy Conversion System WECS based Doubly Fed Induction Generator DFIG using the slip energy recovery principle. The proposed drive system uses a matrix Converter (mC) to transfer the slip energy of the rotor into the mains instead of using cascaded ac-dc-ac converter whilst the stator side is fixed to the grid. Operation at both sub-synchronous and super-synchronous regions is possible with the proposed drive system. The different level control strategies for maximum power point tracking and active-reactive power are discussed. Simulation results of the proposed doubly fed induction generator drive system show the good performance of the control system strategy for both transient and steadystate conditions.

关键词： WECS DFIG Tip Speed Ratio (TSR) PI Control matrix Converter

海沙钛铁矿在硫酸溶液中的电化学溶解研究（英文）

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电化学 2017年第4期23卷 420-428页

作者： m.RostomAli R.K.Biswas md.Golam zakaria 拉杰沙希大学应用化学与化学工程系

采用电化学技术研究了孟加拉国海沙里钛铁矿在硫酸溶液中不同温度下的溶解行为.循环伏安研究表明,在没有添加碳粉的条件下钛铁矿的溶解非常困难.为探明钛铁矿的溶解过程,考察了钛铁矿-碳比例、硫酸浓度和温度对钛铁矿电化学溶解行为的影... 详细信息

采用电化学技术研究了孟加拉国海沙里钛铁矿在硫酸溶液中不同温度下的溶解行为.循环伏安研究表明,在没有添加碳粉的条件下钛铁矿的溶解非常困难.为探明钛铁矿的溶解过程,考察了钛铁矿-碳比例、硫酸浓度和温度对钛铁矿电化学溶解行为的影响.结果显示,钛铁矿在低还原电位和低温下的溶解速率较慢.施加更负的还原电位和在较高的温度下溶解速率加快.增加硫酸浓度(最大浓度达到1 mol·L^(-1))也可提高溶解速率,但在较高的硫酸浓度和还原电位下,由于氢气析出导致钛铁矿的溶解速率降低且气体吸附,最后使得钛铁矿的活性表面积减小.计算得到活化能数值在高温区间为50±10 kJ·mol^(-1),而低温区间为~15±5 kJ·mol^(-1),说明低温区间为扩散控制过程,而高温区间为化学控制过程.

关键词：钛铁矿循环伏安电化学溶解活化能硫酸

Reactivity of 3-Cyanoacetylindole Derivatives: Synthesisof 3-Hydrazonopyrazolyl and 3-Thiadiazolyl Indole Derivatives

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International Journal of Organic Chemistry 2011年第3期1卷 97-104页

作者： Hamdi m. Hassaneen Huwaida m. E. Hassaneen zakaria Ahmed Gomaa 不详

The coupling reaction of 3-cyanoacetyl-2-methylindole 1a with the aromatic diazonium salts gave the corresponding arylhydrazones 2a-e. Compounds 2 were used for synthesis of 4-aminopyrazole-5-carbonitrile 4a-e and 5-amino-4-arylazo-3-pyrazoles 5a-e derivatives. Also, treatment of 3-cyanoacetyl-2-phenylindole 1b with phenyl isothiocyanate gave the corresponding thioacetanilide 7. The later compound 7 was utilized as the key intermediate for the synthesis of some new thiadiazole derivatives 9a-r. The structures of all new compounds were elucidated on the basis of elemental analysis and spectral data.

关键词： 3-methyl Indole 3-Phenyl Indole Phenyl Isothiocyanate Cyanoacetic Acid

Assessment of the Heavy metals and Natural Radioactivity in Phosphate mines and Occupational Health Effects at Some Egyptian Regions

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Journal of Environmental Protection 2016年第11期7卷 1657-1669页

作者： E. R. Atta Kh. m. zakaria m. S. Ibrahim Nuclear and Radiological Regulatory Authority Cairo Egypt

In this work, the specific activities of natural radionuclides, namely 238U series, 232Th series and 40K, have been measured in collected sedimentary phosphate deposits samples from El-Hamraween, El-Quser and Safaga phosphate mines in Egypt. HPGe γ-spectrometry was used. This study was undertaken to estimate the radiation hazard indices in phosphate mining at the studied mines on their occupational workers, to establish correlation relationships between the some measured heavy metals such as As, Cd and Pb in blood workers and their concentration in phosphate rock ores and to determinate the biomarkers in the blood workers such as malondialdehyde (mDA) and superoxide dismutase (SOD). The phosphate mine sample of El-Hamrawein has the lowest activity concentration of 226Ra, 232Th and 40K in comparison to the phosphate mine samples of El-Quseir and Safaga (El-Hamrawein kg-1, 122.4 to 188.3 Bq·kg-1 and 115.4 to 165.8 Bq·kg-1 for Safaga, El-Quseir and El-Hamrawein, respectively. For 232Th activity concentrations varied from 135.6 to 212.3 Bq·kg-1, 112.8 to 167.4 Bq·kg-1 and 132.8 to 188.6 Bq·kg-1 for Safaga, El-Quseir and El-Hamrawein, respectively. For 40K activity concentrations varied from 225.2 to 312.8 Bq·kg-1, 168.7 to 268.9 Bq·kg-1 and 95.2 to 155.8 Bq·kg-1 for Safaga, El-Quseir and El-Hamrawein, respectively. The workers of old ages have higher concentration of the investigated heavy metals than those of young ages. There is a good relation between the concentration of the investigated metals in phosphate mine samples and their concentration in blood of the occupational workers in these mines.

关键词： Superoxide Dismutase malondialdehyde Natural Radionuclides Heavy metals Phosphate Occupational Workers Health Effects

Study of Vitamin D Receptor (VDR) Gene Polymorphisms among Egyptian Cohort Patients with Different Stages of Colorectal Cancer

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Journal of Cancer Therapy 2014年第3期5卷 253-263页

作者： mohamed m. Rizk Nermine H. zakaria Waleed G. Elshazely Clinical Pathology Department Faculty of Medicine Alexandria University Alexandria Egypt Colorectal Surgery Department Faculty of Medicine Alexandria University Alexandria Egypt

Colorectal cancer represents the third cancer worldwide. Studies showed thatinsufficient levels of vitamin D may result in colorectal cancer. Genetic variations in genes controlling vitamin D activity would play a role in determining susceptibility to colorectal cancer. Aim of the work: to study the different genotypes of VDR polymorphisms and detect the association between serum levels of 25(OH)VitD and 1,25(OH)2VitD among sample of Egyptian patients with different stages of colorectal cancer. methods: Ninety patients (60 with different stages of colorectal cancer and 30 patients with benign pathology of the colon) together with 30 healthy controls were examined using PCR-RFLP analysis for FokI, ApaI and TaqI polymorphisms. Results: Genotype distribution for ApaI polymorphism showed no statistically significant difference between patients (colorectal cancer and benign) and controls with p = 0.1. There was no statistically significant difference in FokI polymorphism where p = 0.26 and genotype distribution for TaqI was also insignificant with p = 0.016. The median serum level of 25(OH)VitD was low in cancer cases compared to the control group and benign cases with (p 0.001). There was no statisticallysignificant difference of median serum level of 1,25(OH)2VitD between benign and cancer cases. There was statistically significant difference of median serum level of 25(OH)VitD and 1,25(OH)2VitD between stage I and stage II with (p = 0.004) and (p 0.001), and between stage I and stage III with (p = 0.001)and (p 0.001), but no statistically significant difference between stage II and III with (p = 0.514). Conclusions: There is ethnic variability in vitamin D receptor gene polymorphisms. The lack of significant association of the studied gene polymorphism in our population suggests that its association with other functionally known gene polymorphism might have a role in the pathogenesis of colorectal cancer.

关键词： Vitamin D Receptor (VDR) Colorectal Cancer (CRC) PCR-RFLP (Polymorphism)

Nonlinear Free Vibrations of C-C-SS-SS Symmetrically Laminated Carbon Fiber Reinforced Plastic (CFRP) Rectangular Composite Plates

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World Journal of mechanics 2015年第2期5卷 20-32页

作者： zakaria Zergoune Bilal Harras Rhali Benamar Laboratoire de Génie mécanique Faculté des Sciences et Techniques Fez Morocco Laboratoire d’études et de Recherches en Simulation Université Med V Rabat école Mohammadia d’Ingénieurs Rabat Morocco

The purpose of this paper is to apply the theoretical model developed in References [1] 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003400310032003700320039003100350035000000 -[6] 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000E0000005F005200650066003400310032003700320039003100360030000000 in order to analyze the geometrically nonlinear free dynamic response of C-C-SS-SS rectangular CFRP symmetrically laminated plates so as to investigate the effect of nonlinearity on the nonlinear resonance frequencies, the nonlinear fundamental mode shape and associated bending stress patterns at large vibration amplitudes. Various values of the plate aspect ratio and the amplitude of vibrations will be considered, and useful numerical data also are provided.

关键词： CFRP C-C-SS-SS Rectangular Plates mode Shape Nonlinear Free Vibration Laminate Theory

Wheat yield scenarios for rainwater harvesting at Northern Sinjar mountain, Iraq

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Natural Science 2013年第10期5卷 1057-1068页

作者： Saleh zakaria Nadhir Al-Ansari Sven Knutsson Department of Civil Environmental and Natural Resources Engineering Lulea University of Technology Lulea Sweden

Iraq is part of West Asia and North Africa (WANA) region. The area is known as dry land, famous with gap of crop yield as a result of the water shortage problem. Six basins with total catchment area of 614.19 km2 at rain-fed of Northern Sinjar District (Iraq) had been chosen to investigate both of the potential of rainwater harvesting (RWH) and three supplemental irrigation (SI) scenarios S1, S2, and S3 (100%, 75%, and 50% of full irrigation requirement) to support the wheat yield (bread and durum) under various rainfall conditions for the study period 1990-2009. The results indicated that, the total volume of harvested runoff can be considered for irrigation practices, that reached up to 42.4, 25.1, 0.6, 10.9 (× 106 m3) during 1995-1996, 1996-1997, 1998-1999, and 2001-2002, respectively. The total irrigated area ranged between 10.9 - 5163.7 and 8.8 - 3595.7 (ha) for bread and durum wheat crop for the four selected seasons respectively. The yield scenarios for supplemental irrigation condition Y1, Y2, and Y3 give 68 - 9712, 94 - 12,999, and 105 - 22,806 Ton for bread wheat, and for durum wheat give 56 - 8035, 87 - 10,906, and 103 - 17,396 Ton.

关键词： Rainwater Harvesting Supplemental Irrigation Wheat Yield Sinjar Iraq.

Towards an easier pleurodesis: Ultrasound-guided iodopovidone sclerotherapy in cirrhotic patients with hepatic hydrothorax

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Open Journal of Gastroenterology 2013年第3期3卷 196-201页

作者： Ahmed m. Abdelhafeez mohammed W. zakaria Waleed F. Fathalah Dalia Omran Chest Department Faculty of Medicine Cairo University Cairo Egypt Endemic medicine and Hepatology Department Faculty of Medicine Cairo University Cairo Egypt

Background and Aim: Hepatic hydrothorax is one of the complications encountered in end stage liver disease. Pleural drainage carries the risk of massive protein and electrolyte depletion as well as the risk of bleeding and hepatic encephalopathy. Pleurodesis following pleural aspiration decreases the chance of pleural effusion recurrence, and has been a widely used long-standing method of controlling recurrent pleural effusions. The aim of this study is to evaluate the effect of pleurodesis using ultrasound-guided iodopovidone sclerotherapy in hepatic hydrothorax. Patients and methods: This prospective study included 56 patients with clinical, laboratory and radiological evidence of liver cirrhosis and symptomatic right sided hepatic hydrothorax. All patients were subjected to repeated thoracentesis. Ten ml of lidocaine 2% were injected in the pleural space followed by 20 ml of iodopovidone. The follow-up was done after 3 months. Results: The sclerotherapy procedure was successful in 40 out of 56 cases (71.4%), and the success rate was 66.7% in massive effusion and reached 80% in moderate effusion. Twenty eight patients (50%) had to repeat the procedure for a second time, sixteen of which (28.6%) failed despite the second trial and twelve cases (21.4%) showed no fluid reaccumulation. Conclusion: Ultrasound-guided iodopovidone sclerotherapy is an effective approach for a successful pleurodesis in hepatic hydrothorax.

关键词： Pleurodesis Ultrasound Iodopovidone Effusion

聚乙烯醇乳液改性对汉麻秸秆纤维/水泥基复合材料性能的影响

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复合材料学报 2021年第5期38卷 1567-1575页

作者：王春红左祺支中祥徐磊 SARANI zakaria SHERAZ Hussain Siddique Yousfani 天津工业大学纺织科学与工程学院天津300387 天津工业大学先进纺织复合材料重点实验室天津300387 Bioresources and Biorefinery Laboratory Faculty of Science and TechnologyUniversiti Kebangsaan MalaysiaBangiSelangor 436004 Textile Engineering Department NED University of Engineering&TechnologyKarachi 999010

为解决汉麻秸秆纤维/水泥基复合材料力学性能较差的问题,本文提出采用聚乙烯醇(PVA)乳液对汉麻秸秆纤维/水泥基复合材料进行改性。在优化秸秆纤维的粒径和掺入量后,采用PVA乳液与秸秆纤维和水泥进行共混成型,制备了改性后的汉麻秸秆纤维... 详细信息

为解决汉麻秸秆纤维/水泥基复合材料力学性能较差的问题,本文提出采用聚乙烯醇(PVA)乳液对汉麻秸秆纤维/水泥基复合材料进行改性。在优化秸秆纤维的粒径和掺入量后,采用PVA乳液与秸秆纤维和水泥进行共混成型,制备了改性后的汉麻秸秆纤维/水泥基复合材料。研究了不同质量比的PVA乳液对汉麻秸秆纤维/水泥基复合材料的抗折强度、密度、比强度和弯曲韧性的影响,通过含水率、吸水率及红外光谱测试揭示了PVA乳液对汉麻秸秆纤维/水泥基复合材料的改性机制。结果表明:汉麻秸秆纤维粒径为1700μm及掺入量为12%时,秸秆纤维对汉麻秸秆纤维/水泥基复合材料的增强作用最好。随着PVA乳液质量比的增加,改性后汉麻秸秆纤维/水泥基复合材料的密度逐渐减小,弯曲韧性逐渐提高。当PVA乳液质量比为4.8%时,相较于未改性的汉麻秸秆纤维/水泥基复合材料,改性后的汉麻秸秆纤维/水泥基复合材料抗折强度和比强度分别提高了17.17%和20.50%。通过PVA乳液改性使汉麻秸秆纤维/水泥基复合材料中秸秆纤维与水泥之间的界面得到改善,并缓解了秸秆纤维对水泥水化反应的阻碍作用。

关键词：汉麻秸秆纤维水泥基复合材料聚乙烯醇(PVA)乳液界面水化反应