Engineering Commons^™

Hierarchical Control Strategies For Heaving Wave Energy Converters, Omsalama Mubarak Mohamed Saeed

Theses

This thesis concerned with developing control strategies for a heaving sea wave Energy converter. The objective of this study is to improve captured and converted. Power. In heaving wave energy converters using a robust hierarchical control strategy. This strategy consists of higher and lower hierarchical controller. The higher controller provide a reference velocity signal, whereas the lower one follows the reference despite the uncertainties in the model. In this thesis, two novel methods for the higher controller are proposed. The objective of the first method is to design the intrinsic resistance that maximizes the captured power while considering the constraint …

A Game-Based Learning Model, Fatmah Mohamed Ali Ramsi

Theses

The purpose of this research is to design a conceptual model and develop an implementation as a proof of concept of game-based learning (GBL)to support linguistic skills acquisition. Our model lays the foundations of game-based learning by defining methods, processes, and procedures to support the development of game-based learning systems. Integration of learning and gameplay raises various issues, among them the learning process, learning content, and game characteristics. Language competency is fundamental to academic and social success. Vocabulary acquisition is a primary basis for language competency. Word lists and dictionaries have been used as a resource to enrich vocabulary. The …

An Application Of Fuzzy Logic In Urban Traffic Incident Detection, Feda Wasfi Fayez Mustafa

Theses

Traffic congestion in urban areas is an increasing problem around the world. Traffic incidents (such as accidents) are considered as the major source of traffic congestion. Traffic incidents have negative impacts on traffic flow, air pollution and fuel consumption. As a result, increasing interest in finding new techniques to deal with this issue has been shown. Traffic incident-management systems can decrease the effect of such events and keep roads capacity as close as possible to normal levels. Incident detection system is an important part of any incident management system. This thesis proposes a new approach to incident detection in urban …

Designing Eye Tracking Algorithm For Partner-Assisted Eye Scanning Keyboard For Physically Challenged People, Zeenat S. Al-Kassim

Theses

The proposed research work focuses on building a keyboard through designing an algorithm for eye movement detection using the partner-assisted scanning technique. The study covers all stages of gesture recognition, from data acquisition to eye detection and tracking, and finally classification. With the presence of many techniques to implement the gesture recognition stages, the main objective of this research work is implementing the simple and less expensive technique that produces the best possible results with a high level of accuracy. The results, finally, are compared with similar works done recently to prove the efficiency in implementation of the proposed algorithm. …

Numerical Validation Of Cooling Performance Of Phase Change Materials Integrated Into Heat Sinks For Electronics Cooling, Shaimaa Mohamed Abu Ayyan

Theses

This study aims to analyze the cooling performance of phase change materials (PCMs) integrated into metallic heat sinks (HSs) both experimentally and numerically. For the experimental part of the study, a test setup has been constructed to test PCM integrated heat sinks. The heat sinks are prepared as metallic containments having fins with fixed inter-fin spacing. The volume between the heat sink fins is filled with PCM namely: a paraffin wax, salt hydrate-calcium chloride and milk-fat, then the whole system is sealed for testing under various heat loads at 4W, 6W, 8W and 10W. Four modes of operation are experimentally …

Shear Behavior Of Steel-Fiber Reinforced Ultra-High-Strength Self-Compacted Concrete Beams, Omar Jum’Ah Za’Al Al Rawashdeh

Theses

Ultra-high-strength concrete is a new class of concrete that has been the result of the progress in concrete material science and development. This new type of concrete is characterized with very high compressive strength; about 100 MPa. Ultra-high strength concrete shows very brittle failure behavior compared to normal-strength concrete. Steel fibers will significantly reduce the workability of ultra-high strength concrete. The development and use of self-compacting concrete has provided a solution to the workability issue. The combination of technology and knowledge to produce Ultra-High strength fiber reinforced self-compacting concrete was proved to be feasible. Few studies investigated the effect of …

Accelerated Fog Removal From Real Images For Car Detection, Rawan Ibrahim Khader Younis

Theses

Image de-hazing improves the visual quality of images in computer vision applications, such as object detection and object tracking. Fog removal from car photos taken by street cameras is considered essential to accurate car detection. An accelerated image enhancement technique is presented for car detection as part of an effort to count cars using existing street cameras for the purpose of traffic management. Two aspects of car detection are tackled: 1) An existing image fog removal technique is accelerated by replacing a time consuming image filter with a faster filter while maintaining negligible image degradation, 2) A quick and practical …

A Two-Stage Fuzzy Logic Model For Urban Traffic Signal Control And Management., Nada Bakri Alnaser

Theses

Different traffic signal control systems are applied nowadays. They vary in complexity and approach but mostly aimed at improving the intersection level of service and the efficiency of the traffic network. Fuzzy Logic Models (FLM) have been widely regarded as quite appealing for real-time applications, in addition to their explicit considerations for stochasticities or uncertainties of traffic measures. The majority of the FLMs for signal control were developed to handle isolated intersections in specific. Very few of these FLM systems explicitly account for neighbor intersections’ traffic impact on the decisions to be made at the underlying intersections.

The aim of …

Shear Strengthening Of Reinforced Concrete Beams Using Textile-Reinforced Mortar, Oluwafunmilayo Morenike Awani

Theses

The effectiveness of using carbon textile-reinforced mortar as an innovative technique to improve the shear response of reinforced concrete beams has been investigated. The research comprised double-shear bond testing on bond behavior of textile-reinforced mortar, large-scale beam testing on shear response of reinforced concrete beams strengthened with textile-reinforced mortar, and nonlinear finite element modeling of the tested beam specimens. Test variables of the double-shear bond testing were the matrix type, and width/length of the bonded area, whereas for the large-scale beam testing, the variables included the number of textile-reinforced mortar layers, matrix type, and amount of internal stirrups. Results of …

Modeling And Experimental Study Of Carbon Dioxide Absorption/Stripping In Gas Liquid Membrane Contactor, Nihmiya Abdul Rahim

Dissertations

Natural gas consists primarily of methane (CH4) but it also contains considerable amounts of contaminating compounds mainly carbon dioxide (CO2). The presence of CO2 reduces the heating value of the gas and due to its acidic character causes several operational problems. Hence the removal of CO2 from natural gas is crucially important. The focus of this research work is to investigate the potential for the energy efficient and effective separation of CO2/CH4 gas mixture via lean solvent and regenerating of the rich solvent through absorption/stripping mechanism taking place in a hollow fiber gas liquid membrane contactor process (GLMC) which combines …

Effective Node Clustering And Data Dissemination In Large-Scale Wireless Sensor Networks, Mariam Saeed Ai Nuaimi

Theses

The denseness and random distribution of large-scale WSNs makes it quite difficult to replace or recharge nodes. Energy efficiency and management is a major design goal in these networks. In addition, reliability and scalability are two other major goals that have been identified by researchers as necessary in order to further expand the deployment of such networks for their use in various applications. This thesis aims to provide an energy efficient and effective node clustering and data dissemination algorithm in large-scale wireless sensor networks. In the area of clustering, the proposed research prolongs the lifetime of the network by saving …

Treatment Of Greywater Using Bio Filtration And Permeable Pavement Systems, Assem Mahn El-Ashkar

Theses

Municipal wastewater can be divided into two categories, greywater and black water. Greywater occupies about 75% of total wastewater and are relatively less polluted than the black water. Reuse of greywater is becoming popular in many arid and semiarid regions in order to reduce the municipal water demand. They can be reused for groundwater recharge, landscape irrigation and for toilet flushing. However, the main challenges are their collection, storage and selection of the appropriate treatment system. The United Arab Emirates (UAE) is located in a hyper arid region, having an annual average rainfall of less than 100 mm. Reliable survey …

Seismic Behavior Prediction Of Concentrically Braced Steel Frames, Hani Mohamed Mayez Akkari

Theses

Concentrically braced steel frames (CBFs) are efficient and commonly used steel systems for resisting seismic loads through a complete truss action. In strong earthquake events, multi-storey concentrically braced steel frames (CBFs) are prone to form a storey-collapse mechanism after buckling and yielding of the braces in a storey. This thesis evaluates the seismic performance of steel concentrically braced frames (CBFs) in Abu Dhabi, UAE. The aim of this study is to assess the overall lateral capacity of multi-storey buildings and the associated sequence of formation of plastic hinges using inelastic pushover analysis technique. The time history analysis approach is employed …

Experimental Evaluate Gas Separation Using Ranuehilsch Vortex Tube, Ali Salah Omar Owiemer Omar Owiemer

Theses

Through experimental investigation, this study is offering a closer look into the performance of the vortex tube energy separation and a better understanding of the effect of the vortex tube length, diameter and internal tapering angle on the energy separation. Also the study addresses the effect of inlet pressure on the performance of the vortex tube and the effect of different working fluids (Air, H2 and O2). The vortex tube is a thermal static tube that was discovered by the French scientist George Ranque in 1933 and it is used to separate compressed gas flow into two different streams: one …

Control Strategies For Improving The Performance Of Heaving Wave Energy Converters, Mohammed Abdi Jama.

Dissertations

The main objective of this study is to develop control strategies to enhance the performance of single-body heaving wave energy converters (WECs). Maximizing the energy captured from sea waves while respecting the physical and thermal limitations of the WEC is of a paramount importance for any control strategy to be effective. In addition, it is desirable for the controller to be less vulnerable to model uncertainties and external disturbances. A complete wave-to-wire dynamic model has been derived for the heaving WEC. This includes models that describe the system hydrodynamic forces using the linear wave theory and models that describe the …

Preparation And Characterization Of Copper-Doped And Silver-Doped Titanium Dioxide Nano-Catalysts For Photocatalytic Applications, Haya Abdel Ra'ouf Ahmed

Theses

The goal of this work was to improve the performance of TiO₂ nanomaterials by increasing their optical activities by shifting the onset of the response from the UV to the visible-light region. Among the several ways to achieve this goal, doping TiO₂ nanomaterials with other elements (e.g. metals) was selected to narrow the band gap and enhance the optical properties of TiO₂ nanomaterials. In this work, we have prepared Cu-doped TiO₂ nano-catalysts, characterized them and studied their properties, and the optical ones in particular. The Ag-doped TiO₂ catalyst was prepared by the sol-gel method while …

Preparation And Characterization Of Copper-Doped And Silver-Doped Titanium Dioxide Nano-Catalysts For Photo Catalytic Applications, Haya Abdel Ra’Ouf Ahmed Ra’Ouf Ahmed

Theses

The goal of this work was to improve the performance of TiO2 nanomaterials by increasing their optical activities by shifting the onset of the response from the UV to the visible-light region. Among the several ways to achieve this goal, doping TiO2 nanomaterials with other elements (e.g. metals) was selected to narrow the band gap and enhance the optical properties of TiO2 nanomaterials. In this work, we have prepared Cu-doped TiO2 and Ag-doped TiO2 nano-catalysts, characterized them and studied their properties, and the optical ones in particular. The Ag-doped TiO2 catalyst was prepared by the sol-gel method while the Cu-doped …

Formal Specification And Refinement Of The Navigation Tasks Of Autonomous Robots, Eman Rabiah Rabiah

Theses

Autonomous robots are hybrid systems whose role in our daily life is becoming increasingly critical. They are tasked with various activities requiring reliability, safety, and correctness of their software-controlled behavior. Formal methods have been proved effective in addressing development issues associated with these software qualities. However, even though autonomous robot navigation is a primordial function, there is no research dealing with enhancing reliability of the navigation algorithms. Thus, our focus is to investigate this type of algorithms, and specifically path planning, a fundamental and critical functionality supporting autonomy. We formally address the issue of enhancing reliability of the widely-used A* …

Spectrum Sharing In Cognitive Radio Networks With Quality Of Service Awareness, Nadir Hussin Sulieman Adam

Theses

The goal of this thesis is to study performance of cognitive radio networks in terms of total spectrum utilization and throughput of secondary networks under perfect and imperfect sensing for Additive White Gaussian Noise (AWGN) and fading channels. The effect of imperfect sensing was studied by applying non-collaborative and collaborative sensing techniques using energy detecting and square law combining techniques, respectively. Spectrum allocation for heterogeneous networks in cognitive radio networks was discussed and a new sharing algorithm that guarantee Quality of Service (QoS) for different secondary users’ applications was proposed. The throughput degradation of secondary users due to the activities …

Capacity Models For Multilane Roundabouts And Their Evaluation Using Microscopic Simulation Models, Mohamad A. Shrayteh

Theses

Compared to previous versions of the manual, the Highway Capacity Manual 2010 has provided more comprehensive capacity models for single and multilane roundabouts. The Highway Capacity Manual 2010 multilane roundabout capacity models are limited to two-by-two lanes, that is, two entry lanes and two circulating lanes. These capacity models are not valid for the three-by-three–lane roundabouts (three entry lanes and three circulating lanes) due to different traffic flow characteristics and features. This limitation of the Highway Capacity Manual 2010 model is also clearly mentioned in the manual. In this research, capacity models and curves were developed for three-by-three–lane roundabouts. More …

Structural Response Of Flexure-Deficient Reinforced Concrete Continuous Slabs Strengthened With Composites, Jwan Ahmad Al Khalil

Theses

Accidental reduction in the amount of steel in continuous reinforced concrete (RC) floor slabs is a typical problem that might occur due to an error in design, unclear drawings, or overlooked verification of reinforcement prior to concrete casting. Existence of such deficiencies would compromise the load capacity and serviceability of RC floor slabs. This research examines the effectiveness of using fiber-reinforced polymers (FRP) to improve the structural response of flexure-deficient continuous RC slab strips. The study comprised experimental testing and finite element (FE) modeling. Sixteen two-span RC slab strips, 400 x 125 x 3800 mm each, were tested. Test parameters …

Potential Of Greywater Reuse And Its Effects On Potable Water Demand Management And Downstream Sewer Network, Muhammad Ashfaque Rajput Abdul Hameed

Theses

The UAE’s water demand is rapidly increasing because of population growth, infrastructure development, expansion of agricultural practices and for the desert greening policies. These circumstances force the country to depend on expansive desalinated water and made the country second largest desalination water producer in the world. It is essential to reduce the current water consumption rates by using efficient methods and conservation techniques. Greywater reuse is an effective and promising alternate to cope with this challenge. The study aimed to reduce the water consumption in the Emirate of Abu Dhabi by investigating the potential of greywater reuse. A field survey …

Potential Of Greywater Reuse And Its Effects On Potable Water Demand Management And Downstream Sewer Network, Muhammad Ashfaque Rajput Abdul Hameed

Theses

The UAE’s water demand is rapidly increasing because of population growth, infrastructure development, expansion of agricultural practices, and desert greening policies. These circumstances force the country to depend on expansive desalinated water and made the country the second-largest desalination water producer in the world. It is essential to reduce the current water consumption rates by using efficient methods and conservation techniques. Greywater reuse is an effective and promising alternative to cope with this challenge. The study aimed to reduce water consumption in the Emirate of Abu Dhabi by investigating the potential of greywater reuse. A field survey was carried out …

Optimization Of A Combined Approach For The Treatment Of Desalination Reject Brine And Capture Of Co₂, Ameera Fares Mohammad

Theses

Carbon dioxide (CO₂) is the most widespread greenhouse gas that traps heat and raises the global temperature, contributing to climate change. Existing techniques to sequester carbon dioxide have numerous environmental concerns and usually require an extensive amount of energy. New technologies and methods, such as reactions with desalination reject brine according to the Solvay process, offer new hope for the reduction of carbon dioxide concentration in the atmosphere. Brine management is another environmental concern, as many desalination plants need to find suitable approaches for the treatment or disposal of the large amounts of concentrated brine, resulting from the desalination processes. …

Assessment Of Multi-Story Building Seismic Design Factors With Structural Irregularity, El Sayed Abdel Naby Abdel Aziz Abou Khalifa

Theses

Many high-rise buildings are practically irregular as a result of the architectural and service requirements in the design process, errors and modifications during the construction phase, and changes of the building use throughout its service life. Structural irregularities could increase the uncertainties related to the ability of the building to meet the design objectives. This study is thus devoted to assess the safety margins and calibrate the seismic design response factors of modern high-rise buildings with different vertical irregularity features. A brief survey of the most common vertical irregularities in reinforced concrete multi-story buildings is conducted to select reference structures. …

Assessment Of Multi-Story Building Seismic Design Factors With Structural Irregularity, El Sayed Abdel Naby Abdel Aziz Abou Khalifa

Theses

Many high-rise buildings are practically irregular as a result of the architectural and service requirements in the design process, errors and modification during the construction phase, and changes of the building use throughout its service life. Structural irregularities could increase the uncertainties related to the ability of the building to meet the design objectives. This study is thus devoted to assess the safety margins and calibrate the seismic design response factors of modern high-rise buildings with different vertical irregularity features. A brief survey of the most common vertical irregularities inn reinforced concrete multi-story buildings is conducted to select reference structures. …