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American Journal of Climate Change 2015年第4期4卷 379-384页

作者： Salim Al-Hatrushi Elnazir ramadan Yassine Charabi Department of Geography Sultan Qaboos University Muscat Oman

The Sultanate of Oman has a long coastline extending for about 3165 km including a number of bays and islands. Oman’s coastline borders the Arabian Gulf, the Sea of Oman and the Arabian Sea. Most of this coastline is soft and low laying shore subject to the dynamics of sediment transport and the landward retreat of the shoreline, caused by anthropogenic factors and sea level rise associated with climate change. This paper aims to assess the vulnerability of the entire Omani coastal zone to the expected sea level rise and storm surge. Methodology is based on applying Coastal Vulnerability Index (CVI) to identify clusters of high vulnerability areas according to their sensitivity and dynamic nature and increased risk resulted from seal level rise, erosion and extreme weather events. The coastal line of the governorates of Al Batinah, Muscat and Al-Wusta has scored highly due to possessing similar physical attributes. Based on that assessment a coastal vulnerability database utilizing GIS was created to help stakeholders involved in the coastal management to make better decisions.

关键词： Sea Level Rise CVI Coastal Vulnerability Sultanate of Oman

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微电网中的电源管理

微电网中的电源管理

作者： Mohamed ramadan Bah 华北电力大学(北京)

学位级别：硕士

为了向消费者提供高质量和可靠的电力,必须进行电力管理,使得从发电侧,通过变速器然后到配电侧有稳定的电力流动。微电网是传统电网的缩影,也需要适当的电力管理。微电网大多数时间靠近负载中心连接,使用可再生能源,如太阳能光伏板,风... 详细信息

为了向消费者提供高质量和可靠的电力,必须进行电力管理,使得从发电侧,通过变速器然后到配电侧有稳定的电力流动。微电网是传统电网的缩影,也需要适当的电力管理。微电网大多数时间靠近负载中心连接,使用可再生能源,如太阳能光伏板,风力涡轮机,微型涡轮机等。微电网既可以在电网连接模式下运行,也可以在自主模式下运行。因为大多数微电网是使用电子接口分布式发电来操作的,所以它们具有低惯性。因此,需要进行适当的控制,以便在瞬态情况下几乎没有影响。要控制以确保可靠和高质量功率流的组件是实际或有功功率,无功功率,电压和频率。无论负载条件或发电条件如何,在操作微电网时应该减少干扰。应该有足够的有功功率和适当的无功功率补偿。无论何时发生加载,都必然会降低频率。然而,这应该以这样的方式控制,即没有振荡会导致进一步的问题。与具有并联连接的逆变器的微电网相关的另一个问题是流过这些逆变器的循环电流。这种现象的主要影响是功率质量差和可能的热量累积。这种效果肯定是不可取的,需要加以解决。在这项研究中,有两个并联的逆变器。还连接了本地负载以及一般负载。本地负载在不同时间连接,其中一个负载在一段时间后断开。这是为了在装载和卸载期间测量实际功率和无功功率的流量。在此期间也观察到频率。最后,还观察流过逆变器的循环电流,看它足否在可接受的范围内。所有这些都是使用MATLAB Simulink实现的,结果将在此后生成。

关键词：微电网电力管理逆变器循环电流

More Insight on Structure of New Binary Cerium Borate Glasses

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New Journal of Glass and Ceramics 2018年第1期8卷 12-21页

作者： Gomaa El-Damrawi Fawzeya Gharghar Rawya ramadan Glass Research Group Physics Department Faculty of Science Mansoura University Mansoura Egypt Microwave and Dielectric Department Physics Division National Research Centre Giza Egypt

The structure of glasses in the system of xCeO2(100?-?x)B2O3, x = 30, 40, 50 mol% CeO2 has been explored for the first time by correlation between data obtained from XRD, FTIR and 11B NMR analyses. NMR spectroscopy andFTIR spectroscopy have confirmed that transformation rate of BO3 to BO4 groups is reduced by CeO2 *** concentration of Ce4-O-Ce4 is increased at the expense of both B4-O-Ce4 and B3-O-B4 linkages. Boron atoms are mainly coordinated with Ce4 sites as second neighbors due to increasing CeO4 species with further increase of CeO2 concentration. Increasing B4 fraction is considered due to forming of CeO4 with rate higher than that of BO4 units. The change of chemical shift of 11B nuclei upon exchanging B2O3 with CeO2 confirms that the central boron atoms would be coordinated with tetrahedral cerium atoms as second neighbors. The X-ray diffraction of cerium rich glass is clearly indicated that the formation of crystalline phases refers to CeO4, CeBO3and Ce(BO2)3 species.

关键词： Borate Cerium Former Units NMR Analysis

Evaluation of Merge Control Strategies at Interstate Work Zones under Peak and Off-Peak Traffic Conditions

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Journal of Transportation Technologies 2016年第3期6卷 118-130页

作者： Ossama E. ramadan Virginia P. Sisiopiku Department of Civil Construction and Environmental Engineering University of Alabama at Birmingham Birmingham USA

Maintenance and rehabilitation projects of interstate facilities typically mandate lane closures. Lane closures require merging maneuvers that often result in reduced speeds and traffic bottlenecks. Work zone impacts on traffic operations are magnified when project durations are extended. Conventionally, work zone traffic control plans are developed to address work zone impacts. This study evaluated various merge control strategies at interstate work zones peak and off-peak traffic conditions and summarized related impacts. A comprehensive microscopic simulation model was developed in full consideration of driver/vehicle behavior at work zones. The analysis of simulation results revealed that merge control strategies, when implemented during peak and off-peak conditions, can preserve the level of service and provide favorable mobility, safety, and environmental impacts. In addition, results indicate that transportation agencies’ practice of scheduling work zone activities during the off-peak may not be the most optimum approach. Overall, the findings of this study highlight the need for evaluation of work zone scheduling practices in full consideration of agency, user, and project costs.

关键词： Traffic Simulation Bottlenecks Work Zone Traffic Control Traffic Congestion

Medicinal and biological values of Callistemon viminalis extracts:History,current situation and prospects

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Asian Pacific Journal of Tropical Medicine 2017年第3期10卷 219-226页

作者： Mohamed Z.M.Salem Mervat EL-Hefny ramadan A.Nasser Hayssam M.Ali Nader A.El-Shanhorey Hosam O.Elansary Forestry and Wood Technology Department Faculty of Agriculture(El-Shatby)Alexandria UniversityAlexandriaEgypt Department of Floriculture Ornamental Horticulture and Garden DesignFaculty of Agriculture(EL-Shatby)Alexandria UniversityAlexandriaEgypt Department of Botanical Gardens Research Horticultural Research Institute(ARC)AlexandriaEgypt King Saud University College of ScienceDepartment of Botany and MicrobiologyPO Box 2455Riyadh 11451Saudi Arabia Agriculture Research Center Horticulture Research InstituteSabahia Horticulture Research StationDepartment of Timber Trees ResearchAlexandriaEgypt

Callistemon viminalis(***)is a plant that has been reported to have a various medicinal values such as antibacterial,antifungal,antioxidant activities and other pharmaceutical and insecticidal *** review covers the potentials,applications and properties of different extracts from different parts(branches,flowers,fruits,bark,leaves)of ***,the chemical structures of the bioactive compounds were reported for biological *** the results supported the traditional uses of *** in folk *** addition,some researches supported the use of *** extracts for the preparation of metal oxide nanoparticles.

关键词： Callistemon viminalis Antibacterial activity Antioxidant activity Antifungal activity Essential oils Biological activities

Synthesis of Some Aminopicolinic Acids

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Journal of Chemistry and Chemical Engineering 2012年第4期6卷 372-377页

作者： ramadan A. Bawa Ahela M. Beatty Department of Chemistry University of Misurata P 0 Box 875 Misurata Libya Department of Chemistry University of Missouri -St. Louis St. Louis MO 63121-4400 USA

Some aminopicolinic acid derivatives have been synthesized and fully characterized. These pyridine derivatives were 4-aminopicolinic acid, 4-（4-aminophenylethynyl） picolinic acid and 4-（3-aminophenylethynyl） picolinic acid. In addition to these compounds, other substituted picolinic acids were made throughout the synthetic paths.

关键词： Aminopicolinic acid Sinogoshira coupling reaction synthetic paths.

Quantitative Determination of Cd and Pb in Tissues and Organs of Chickens Raised in El-Jabel Alakhder Region—Libya

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Food and Nutrition Sciences 2013年第8期4卷 763-766页

作者： ramadan E. Abdolgader ramadan A. Hussain Salah M. Hasan Agoub A. Agoub Department of Food Science and Technology Faculty of Agriculture Omar Almukhater University Bayda Libya.

This study was carried out to determine the concentration of Cd, and Pb in the tissues of thigh, breast, liver, heart, gizzard, neck and skin of chicken. All samples were collected in the summer of 2004 from three different commercial farms of chickens production located in different areas of EL-Jabal Alakhder region at Libya country (Gernada, EL-Abrak and Sousa). For comparison, the metals were also determined in the same tissues of the chickens which produced in the national station of poultry production at EL-Akhoria city. The metals in the chickens feed and in water for both drinking and cleaning inside the slaughter house were also determined. The results revealed that the highest concentrations of Cd were found in neck, liver and heart while the neck and skin tissues contained the highest level of Pb. However, the tissues of thigh and breast flesh had the lowest level of metals. The levels of Cd in the different tissues ranged from 0.008 to 0.227 ppm and from 0.093 to 2.391 ppm for Pb. The results revealed that the levels of Cd in neck from all farms, liver from both EL-Akhoria and Gernada farms. Levels of Pb in the neck and skin from all farms were exceeding the permitted limits according to some European regulations. The results also indicate that the high concentrations of Cd in some tissues were due to the effect of high levels of these metals in the feed of birds. However the drinking and cleaning water had no effects on the level of the metals in the different tissues.

关键词： Chicken Heavy Metals Lead Cadmium

Characterization and Impact of Cattle Manure Particle Size on Physical Properties of Sandy Soils

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Journal of Geoscience and Environment Protection 2019年第8期7卷 180-194页

作者： Doaa Ahmed El-Nagar ramadan Abd Alaaty Mohamed Soil Improvement Department Soil Water and Environment Institute (Agricultural Research Center) Egypt Vegetable Crops Department Horticulture Research Institute (Agricultural Research Center) Egypt

Sandy soils have poor physical properties, which cause them to drain quickly and not hold water well;however, with the addition of cattle manure, sandy soil can be improved. Therefore, experiments were conducted to investigate the characterization and impact of different particle sizes of cattle manure (CMS) on improving some physical properties of sandy soil and thus the yield of lettuce. Cattle manure was ground to powder and was sieved with three different Particle sizes 4.76-2 (CMS1), 2-0.8 (CMS2), 0.8-0.4 (CMS3) mm. Some physical properties were measured for different Particle sizes of manure. A batch of sorption experiments was carried out to study the role of different Particle sizes of manure on adsorption of N, P and K from aqueous solution. Two experiments were carried out on sandy soil (pots and field) to study the impact of adding CMS (5 ton/fed) to enhance some physical properties of sandy soil. The results indicated that the physical properties of cattle manure changed based on particle size fractionation, where Bulk density and saturated water holding capacity increased as particle size decreased, while porosity reduced as particle size decreased. The results of the sorption parameters of N, P and K on different particle sizes of manure indicated that maximum sorption occurred on CMS 3 for both P and K according to Langmuir and Freundlich sorption models. Two experiments showed that CMS had affected significantly the total porosity (TP), bulk density (Bd), slowly drainable pores (SDP), water holding pores and (WHP) available water (AW) in comparison to control. The CMS had a slight effect on Quickly-drainable pores (QDP) and fine capillary pores (FCP) as compared to the control in both experiments. Fresh weight, dry weight and number of leaf lettuce increased significantly with decreasing particle sizes of cattle manure as compared to control.

关键词： Cattle Manure Size Soil Properties Langmuir and Freundlich Sorption Models

Effect of SrO on the Structure of Apatite and Wollastonite Phases of Na2O-CaO-SiO2-P2O5Glass System

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New Journal of Glass and Ceramics 2021年第2期11卷 45-56页

作者： Gomaa El Damrawi Rawya Mhammed ramadan Mohamed El Baiomy Glass Research Group Physics Department Faculty of Science Mansoura University Mansoura Egypt Microwave Physics and Dielectrics Department Physics Research Division National Research Centre Cairo Egypt

Glasses in the system 24.5Na2O·24.5CaO·6P2O5·xSrO·(45-x)SiO2 have been studied in the composition region of x = 0 - 15 mol%. The as prepared glasses are transparent and have an amorphous network structure. On the otherhand, heat treated glasses are transformed to opaque white glass ceramic characterized by their highly crystalline network structure. Crystalline apatite (calcium phosphate, Ca3(PO4)2, wollastonite (calcium silicate, CaSiO3), and strontium calcium phosphate Ca2Sr(PO4)2 are the main well-formed cry

关键词： Structure Physical Properties Gasses Glass Ceramics

Integrating Geotechnical Investigation with Hydrological Modeling for Mitigation of Expansive Soil Hazards in Tabuk City, Saudi Arabia

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Open Journal of Modern Hydrology 2017年第1期7卷 11-37页

作者： Abd-Alrahman Embaby Ayman Abu Halawa Medhat ramadan Geology Department Faculty of Science Damietta University Damietta Egypt Nuclear Material Authority Cairo Egypt

Due to global climatic changes, flash floods are followed as a yearly disaster with high magnitude of influence. During the years 1981, 1988, 2010, 2012 and in January 2013, Tabuk city, northwest of Saudi Arabia suffered huge flash floods. These are major factors affecting on the swelling behavior of expansive Tabuk shale. The examined geotechnical properties of the surface and subsurface lithology of the sedimentary deposits distinguished Tabuk city into three zones. The expansive zone is spread in the middle and the non-expansive zones are distributed in the east and west of the city. The Watershed Modeling System (WMS) and Hydrologic Engineering Center (HEC-1) models were used to delineate and identify the drainage system and basin morphometry, where flash floods and accumulation of water might take place. Integration between geotechnical distribution maps of the expansion soil and surface hydrological data in terms of runoff maps was done. It has been identified the whereabouts the soils which have expansion characteristics and areas prone to flooding and surface runoff. They are helpful in defining the hazard zones map. Based on this map, it can be avoided constructions on the risk neighborhoods such as Al Qadsiyah, Al Maseif, Arrwdah, Al Nakhil and Al Rajhi. Also, it can suggest that the western side of Tabuk city is suitable for future urban extension. These results will help planners and citizens to create alternative development scenarios and determine their impact on the future urbanization patterns. Moreover, the direction of surface runoff flow or storm water discharge should be away from the expansion soil areas. Therefore, constructing dams on the outlet of the high-risk basins, south of Tabuk city is an important solution to control flash flood events, as well as increase groundwater recharge.

关键词： Expansion Soil Hazards Flash Floods Geotechnical Investigation Saudi Arabia Tabuk City Watershed Modeling System