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Analysis of urban growth at Cairo, Egypt using remote sensing and GIS

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Natural Science 2012年第6期4卷 355-361页

作者： mohamed E. Hereher Department of Environmental Sciences Faculty of Science at Damietta Mansoura University Mansoura Egypt

The main objective of the present study was to highlight and analyze the exchange between the land cover components at Cairo with focusing on urban area and agricultural land between 1973 and 2006 using Landsat satellite data with the aid of Digital elevation Models (DEM). The techniques utilized in this investigation involved a rigorous supervised classification of the Landsat and the DEM images. Results showed that urban area of Cairo was 233.78 km2 in 1973 and increased to 557.87 km2 in 2006. The cut-off from agricultural lands was 136.75 km2, whereas urbanization into the neighboring desert was estimated at 187.32 km2 for the same period. The direction of urban sprawl was mainly controlled by regional topography. Urban sprawl was attributed mainly to accelerated population growth.

关键词： Cairo Urban Sprawl Landsat

High-Performance CMOS Current Mirrors: Application to Linear Voltage-to-Current Converter Used for Two-Stage Operational Amplifier

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Circuits and Systems 2012年第4期3卷 311-316页

作者： Radwene Laajimi mohamed Masmoudi Department of electrical Engineering electronics Micro-Technology and Communication (EMC) Research Group Sfax (ENIS) Uni-versity of Sfax Sfax Tunisia

This paper presents two schemes of high performance CMOS current mirror, one of them is used for operational tran-sconductance amplifier (OTA) in analog VLSI systems. The linearity, output impedance, bandwidth and accuracy are the most parameters to determine the performance of the current mirror. Here a comparison of two architectures based on same architecture of the amplifier is presented. This comparison includes: linearity, output impedance, bandwidth and accuracy. These two circuits are validated with simulation in technology AMS 0.35 μm. An operational amplifier based on the adapted current mirror is proposed. Its frequency analysis with large bandwidth is validated with the same technology.

关键词： Analog Circuits Current Source Current Mirror Low Voltage Operational Transconductance Amplifier

Attitude Stabilization Using Modified Rodrigues Parameters without Angular Velocity Measurements

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World Journal of Mechanics 2011年第2期1卷 57-63页

作者： Awad el-Gohary Tawfik el-Sayed Tawfik 不详

The optimal stabilization of a rigid body motion without angular velocity measurements is considered with the help of three internal rotors that effected by internal frictions. In this paper, the orientation of the body will be described in terms of the Modified Rodrigues parameters (MRPs). The optimal control law which stabilizes asymptotically this motion and minimizes the require like-energy cost is obtained in terms of the MRPs. Numerical study and simulation are introduced.

关键词： Attitude Control Rotors with Frictions Modified Rodrigues Parameters

Friction Stir Welding of Dissimilar Aluminum Alloys

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World Journal of Engineering and Technology 2018年第2期6卷 408-419页

作者： Hassan Abd el-Hafez Abla el-Megharbel Department of Production Engineering and Mechanical Design Faculty of Engineering Port Said University Port Said Egypt

Dissimilar aluminum alloys AA2024-T365 and AA5083-H111 were welded by friction stir process. Welding parameters such as tool rotational speed (900, 1120 and 1400 rpm), weld speeds (16, 40 and 80 mm/min) and tool pin profiles (square, triangular and stepped) were used to weld many joints to study their effect on the mechanical properties of the joint. Also, different locations of the material were studied as other parameter. The mechanical properties were evaluated using tensile and hardness tests. The microstructure characterization of the processed alloys was carried out using optical microscopy. Macro and microstructures of parent and welded specimens indicated that the weld parameters have a significant effect on mechanical and microstructural properties of the welds. However, defect-free as well as higher strength was obtained at higher speed of 80 mm/min.

关键词： Friction Stir Welding Dissimilar Aluminum Alloys Welding Parameters Metallographic AA7075 AA5083

3D Finite elements Technique for Collapse Causes of the Pylons in Egyptian Temples: A Study of the Great Pylon of Ramesseum Temple, Luxor, Egypt

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Open Journal of Geology 2019年第13期9卷 1022-1041页

作者： Essam H. mohamed Archaeological Conservation Department Faculty of Archaeology South Valley University Qena Egypt

This research presents damage causes of the pylons in the ancient Egyptian temples based on 3D finite elements analysis. The main purpose of the research determines the failure causes of the first pylon of the Ramessium temple, which is situated in Upper Egypt, at Luxor “Thebes” on the west bank of the Nile River. The first pylon of Ramessium temple subjected to seismic activity effects on long term, combined with several structural damage factors such as the defects resulting from the construction technique, where the builder used the poor quality of stones in foundations of the pylon, the building materials residue was used as filler for the core of the pylon walls, and it lacked vertical joints between the courses. In addition to it founded on alluvial soil that is vulnerable to contaminated water, it is still suffering damage factors and urban trespasses at the moment. All of the former factors helped the pylon to be affected by the earthquakes loads that occurred on it. The structural behavior of the pylon under self-weight and earthquakes loads were carried out by Numerical analysis to find out the loads and stresses which caused collapsing of the pylon. Results of the study indicated that the pylon subjected to a horizontal displacement due to old earthquakes force, led to collapse of the pylon. Finally, the study represents use of modern technique to study the structural behavior of the most important architectural units in ancient Egyptian temples to identify the causes of its collapse.

关键词： The Great Pylon of Ramessium Temple Collapse Causes 3D Finite elements Numerical Models Horizontal and Vertical Displacement

Pattern-Oriented Approach for Enterprise Architecture: TOGAF Framework

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Journal of Software Engineering and Applications 2012年第1期5卷 45-50页

作者： mohamed Taleb Omar Cherkaoui 不详

Design pattern suggests that developers must be able to reuse proven solutions emerging from the best design practices to solve common design problems while composing patterns to create reusable designs that can be mapped to different types of enterprise frameworks and architectures such as The Open Group Architecture Framework (TOGAF). Without this, business analysts, designers and developers are not properly applying design solutions or take full benefit of the power of patterns as reuse blocks, resulting in poor performance, poor scalability, and poor usability. Furthermore, these professionals may “reinvent the wheel” when attempting to implement the same design for different types of architectures of TOGAF framework. In this paper, we introduce different categories of design patterns as a vehicle for capturing and reusing good analyses, designs and implementation applied to TOGAF framework while detailing a motivating exemplar on how design patterns can be composed to create generic types of architectures of TOGAF framework. Then, we discuss why patterns are a suitable for developing and documenting various architectures including enterprise architectures as TOGAF.

关键词： Design Patterns Enterprise Architecture TOGAF Framework

Effect of static magnetic field on erythrocytes characterizations

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Journal of Biomedical Science and Engineering 2010年第3期3卷 300-303页

作者： mohamed A. elblbesy 不详

The interaction of static magnetic field (SMF) with living organisms is a rapidly growing field of investigation. Recently, exposure to moderate intensity SMFs (1 mT – 1 T) has attracted much attention for its various medical applications. This study was designed to show the microscopic effect of SMF on erythrocytes in vitro. For this purpose SMF system was constructed in my lab on basis of the idea of cell tracking velocimetry system. The changes in erythrocytes surface area, sphericity, and adhesion number for erythrocytes were calculated to quantify the effect of SMF on erythrocytes characterizations. The results showed that SMF increased erythrocytes surface area and reduced their sphericity. The adhesion number of erythrocytes under the influence of SMF showed the tendency of erythrocytes to adhere with each other. These findings indicate that more study on microscopic scales must be carried out in order to investigate the effect of SMF on erythrocytes.

关键词： Static Magnetic Field Erythrocytes Surface Area Shericity Adhesion

Effect of Nanoparticles Reinforced Adhesive Layers on Microleakage of Tooth Restorations

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World Journal of Nano Science and Engineering 2016年第2期6卷 64-69页

作者： mohamed I. Ebrahim mohamed Ashour Ahmed Nayef H. Felemban Department of Restorative Dentistry Faculty of Dentistry Taif University Taif Saudi Arabia Department of Prosthodontics Faculty of Dentistry Taif University Taif Saudi Arabia Department of Orthodontics Faculty of Dentistry Taif University Taif Saudi Arabia

Adhesive layer is an essential part of tooth colored restorations which play an important role in decreasing the microleakage between the tooth and restoration material after polymerization shrinkage. The purpose of this study was to evaluate the effect of deferent adhesive system of bonding agent on microleakage of nanocomposite resin in class II cavities. Two different types of adhesive systems: universal adhesive (ExciTE) and a newly developed adhesive (Nano-Bond) and one type of light-cured resin restorative material (nanocomposite resin) were used in this study. These adhesives were applied to prepared tooth cavities by either manufactures’ instructions or by an experimental method (single or double application). Nanocomposite resin was then placed and light-cured for 40 seconds. Teeth were subjected to 500 thermal cycles between 5°C and 55°C and were immersed in 3% methylene blue solution for 24 hours;microleakage was observed microscopically. The data were analyzed by a two-way ANOVA. For comparison between groups, Tukey’s post-hoc test was used. Nanoparticles reinforced adhesive system shows low microleakage in compare with universal adhesive system, and application of two adhesive layers also can decrease the microleakage. The ability of stress absorption by adhesive layer after polymerization shrinkage of restoration material will reduce the microleakage.

关键词： Adhesive Layer Tooth Colored Restorations Nanoparticles Microleakage

Using Successive Multi-Goals Method in the Individual-Based Model to Simulate Crowd Behavior during Evacuation Processes

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Journal of Mechanics Engineering and Automation 2011年第4期1卷 325-330页

作者： mohamed H. Mabrouk Egyptian Armed Forces Cairo 00202 Egypt

The fact of proportional population growth in many countries drags the attention of researchers in the field of crowd dynamics to the need for developing reliable models to predict the behavior of human crowds in emergency situations such as evacuation processes. Computer based models that simulate human crowd dynamics prove to offer the optimum way to predict the crowd realistic behavior especially in emergency situations. This paper presents a vital extension of my previous work in which an individual-based model to simulate the behavior of human crowd was developed using the artificial potential fields to describe the interaction forces between each crowd member and the environment on one side and amongst the crowd members on the other side to add realistic flavor to the predicted crowd behavior. In this paper, the successive multi-goals (SMG) method, which is a new method to represent the environment in which the crowd moves, is developed. Rather than using the traditional static potential field, the successive multi-goals method uses a dynamic potential field which is vital to solve the reactive problem that is considered as a drawback of the model when simulating the human crowd behavior during evacuation of buildings whose structures are complex such as bottlenecks and narrow corridors. Numerical results that match the real behavior of human individuals in emergency situations prove the efficiency of the new method to solve the problem on an individual basis as well as its applicability.

关键词：计算机模拟人群行为动态模型疏散基础目标法紧急情况人工势场