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Finite Element Modeling of Drilling AZ91 Magnesium Foam Reinforced with Hollow Alumina Microspheres
No full textA Master of Science thesis in Mechanical Engineering by Abdalla Mohammed entitled, “Finite Element Modeling of Drilling AZ91 Magnesium Foam Reinforced with Hollow Alumina Microspheres”, submitted in July 2021. Thesis advisor is Dr. Sathish Kannan. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Novel AZ91 magnesium syntactic foams are a potential choice for temporary biomedical implants. In many cases, holes of various sizes need to be machined on the biomedical implants using the drilling process to facilitate placement of implants inside the human body. In this study, the drilling performance of AZ91-magnesium foam is investigated under different lubrication methods such as dry, wet (Almag® mineral Oil), and cryogenic cooling. Drilling experiments were carried out using titanium aluminium nitride (TiAlN) physical vapor deposition (PVD) coated and uncoated twist drills on varying volume fractions of AZ91 magnesium syntactic foams (5%, 10%, and 15%) reinforced with hollow alumina microspheres. Test results showed a 30%-60% higher thrust forces generated with cryogenic machining compared to dry and wet machining while cutting AZ91-15% hollow alumina foam. This phenomenon shows the influence of alumina hollow microspheres on controlling the plastic deformation of the AZ91 magnesium matrix through effective work hardening and characteristic load transfer. Scanning electron microscope (SEM) investigation of cryogenic machined bore surfaces showed minimal drilling-induced surface defects. Based on the analysis carried out, cryogenic machining is recommended as a sustainable drilling process for AZ91-magnesium syntactic foams. A three-dimensional, thermo-mechanical finite element-based model for drilling magnesium syntactic foam using AdvantEdgeTM is presented for different lubrication conditions. Metal cutting tests are performed and comparison with predicted data is provided. The predicted machining induced stress from the finite element model showed a compressive stress in case of cryogenic cooling compared to dry machining which will give a better surface integrity and quality to the machined surface and will reduce the danger of crack propagation and crack growth. Based on the analysis carried out, cryogenic machining is recommended as a sustainable drilling process for AZ91-magnesium syntactic foams.College of EngineeringDepartment of Mechanical EngineeringMaster of Science in Mechanical Engineering (MSME
A Feasibility Study for Solar Energy Generation Policy Mechanisms in The UAE
No full textA Master of Science thesis in Engineering Systems Management by Mayyas Abdelrahman Rashid Alsalman Al-Ali entitled, “A Feasibility Study for Solar Energy Generation Policy Mechanisms in The UAE”, submitted in November 2021. Thesis advisor is Dr. Vian Ahmed. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).In a modern world, life would not be possible without energy, as energy plays a significant role in the development of nations. The rapid economic growth combined with the increasing energy demand is a continuous driving force for economic development, social advancement, and improved quality of life. Over the past few decades, the impact of energy demand on the environment has increased the focus of global nations on the sustainability efforts to reduce the greenhouse gas emissions that require intervention and a shared sense of responsibility in reducing emissions. Studies revealed that the energy sector alone accounts for two-thirds of greenhouse gas emissions as more than 80% of energy needs are satisfied using hydrocarbon-based resources. The GCC is a known region for its substantial hydrocarbon resources; besides, the GCC's energy sector is the primary source of CO# due to fossil fuel usage as the energy demand in this region is estimated to increase above the world average by 3% yearly. Upon looking into the UAE's case, it was found that due to the rapid economic growth, the UAE is among the world's highest CO# emitters, which contributes to 0.7% of the world's annual emission due to fossil fuel consumption. Thus, renewable energy policy mechanisms are needed to support renewable energy deployment in the UAE to achieve a significant renewable energy share in the national mix. As such, several energy policy mechanisms promote renewable energy deployment, which includes feed-in-tariffs, metering, renewable energy auctions, quotas, and investment tax credits that are merely confined to two emirates Abu Dhabi and Dubai. Such policy mechanisms indicate a gap between the policy formulations and their actual implementation within the UAE, which impacts the long-term energy consumption dependent on fossil fuels. Therefore, this study intends to evaluate the techno-economic analysis of the factors affecting renewable energy deployment by using HOMER Grid Software. Also, to recommend solar energy generation in the UAE by encouraging electricity authorities to adopt the most feasible policy mechanism, which aligns with UAE's strategy in attaining sustainable growth to meet the local demand.College of EngineeringDepartment of Industrial EngineeringMaster of Science in Engineering Systems Management (MSESM
Design of a High Power, LCC-Compensated, Dynamic, Wireless Electric Vehicle Charging System with Improved Misalignment Tolerance
No full textDynamic wireless power transfer (DWPT) systems are becoming increasingly important for on-the-move electric vehicle (EV) charging solutions, to overcome range anxiety and compensate for the consumed energy while the EV is in motion. In this work, a DWPT EV charging system is proposed to be implemented on a straight road stretch such that it provides the moving EV with energy at a rate of 308 Wh/km. This rate is expected to compensate for the vehicle’s average energy consumption and allow for additional energy storage in the EV battery. The proposed charging system operates at an average power transfer efficiency that is higher than 90% and provides good lateral misalignment tolerance up to ±200 mm. Details of the proposed system’s design are presented in this paper, including EV specifications, inductive link and compensation network design and power electronic circuitry.American University of SharjahSharjah Research Academy (SRA
Development of a Smart System for Leak Detection in Water Distribution Networks
No full textA Master of Science thesis in Civil Engineering by Doha Hesham Elshazly entitled, “Development of a Smart System for Leak Detection in Water Distribution Networks”, submitted in December 2021. Thesis advisor is Dr. Tarig A. Ali and thesis co-advisor is Dr. Md. Mortula. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Water is a critical source of life for the human society, which needs to be sustained. Every year, a considerable portion of water is lost from water distribution networks (WDNs) due to leaks. This is accompanied by significant consequences including, economic losses and supply disruption, which are major concerns for water utility companies. Hence, a robust and timely leak detection method is necessary to conduct corrective maintenance so as to minimize the underlying consequences. Previous studies have investigated the efficiency and effectiveness of various nondestructive detection methods including ground penetrating radar (GPR), spectrometry, and infrared sensing. Based on the outcome of the recent research on leak detection using infrared sensing, this study aims to develop a smart leak detection system that integrates remote sensing and geographic information system (GIS). The proposed system is to be used by a drone, equipped with an infrared (IR) camera, and geospatial analysis tools that incorporate remote sensing and GIS for near-real time leak detection. In addition, this study utilizes currently installed pressure, flow and water quality monitoring sensors in WDNs. A GIS customized interface was developed to automate the leak detection system and allow for timely data processing. The proposed system was validated on a section of the WDN in the city of Sharjah, in collaboration with Sharjah Electricity and Water Authority (SEWA). The results obtained in this research proved the efficiency of the proposed method for leak detection in WDNs.College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE
A Fluorescence-Based Chemical Sensor for Detection of Melamine in Aqueous Solutions
No full textMelamine, an industrial chemical, receives wide attention nowadays because of its unethical usage as a nitrogen enhancer in protein-rich foods and dairy products. Since most of the existing melamine detection methods are highly expensive and time-consuming, high sensitivity biosensorbased detection methods have arisen in the scientific literature as promising alternatives. This study reports the design, synthesis, and fluorescent investigations of a carbazole-based sensor (CB) for the detection of melamine in aqueous solutions. The titration studies and microplate experiments on a CB-cyanuric acid mixture (CB-CA) with melamine suggested that the novel sensor could detect melamine even at very low concentrations in both aqueous solutions and dairy samples.American University of Sharja
Identifying the Inherent Factors Causing Delays in the UAE Construction Industry
No full textA Master of Science thesis in Engineering Systems Management by Haitham Alajmani entitled, “Identifying the Inherent Factors Causing Delays in the UAE Construction Industry”, submitted in April 2021. Thesis advisor is Dr. Sameh El-Sayegh. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).The construction industry is one of the most important industries that impact the economy of a country as it contributes significantly to the GDP, employment, and wealth. The UAE construction industry contributes to 8.7% of the overall GDP which makes it a key industry for the country’s economy. The industry is challenged with several risks that plague the performance of the projects where most projects experience significant delays. Some of the consequences of the delays include loss of revenues for the owners, loss of future opportunities for the contractors, and litigation. The UAE has one of the most dynamic economies in the world, but it has also been suffering from delays in the execution of its construction projects. There is lack of recent research that identifies the most frequent, severe, and important causes and effects of delays in the UAE construction industry. This thesis aims to scrutinize the construction industry in the UAE and determine the most important causes of delays, the most frequent factors, the most severe factors, and the most important effects of delays. A total of 40 delay causes and 10 effects were identified through the literature review. A questionnaire was prepared and distributed to professionals in the UAE construction industry. A total of 128 responses were received and analyzed from owners, consultants, contractors, and the overall perspectives. Overall, the most important causes of delays were “Award the project to the lowest bidder”, “Delay in progress payment by the owner”, and “Change orders by the owner”. A high level of agreement was found between the consultants and contractors according to Spearman’s rank correlation results. The most frequent cause of delay was found to be “Award the project to the lowest bidder” while the most severe cause was found to be “Financial crisis”. The most likely effects were “Time overrun/extension of time” and “Poor quality of work due to hurrying the project”. Using Factor Analysis, 6 components are extracted explaining 83.87% of the total variance. Several recommendations are provided to mitigate the delays and to reduce the frequency and impact of the key causes.College of EngineeringMultidisciplinary ProgramsMaster of Science in Engineering Systems Management (MSESM
Modeling Strategies of Finite Element Simulation of Reinforced Concrete Beams Strengthened with FRP: A Review
No full textFiber-reinforced polymer (FRP) composites do not only possess superior mechanical properties, but can also be easy to tailor, install, and maintain. As such, FRPs offer novel and attractive solutions to facilitate strengthening and/or retrofitting of aging, weakened, and upgraded structures. Despite the availability of general code provisions, the design and analysis of FRP-strengthened concrete structures is both tedious and complex—especially in scenarios associated with unique loading conditions. As such, designers often leverage advanced finite element (FE) simulation as a mean to understand and predict the performance of FRP-strengthened structures. In order to narrow this knowledge gap, this paper details suitable strategy for developing and carrying out advanced FE simulations on FRP-strengthened concrete structures. The paper also covers techniques related to simulating adhesives (bonding agents), material constitutive properties and plasticity (cracking/crushing of concrete, yielding of steel reinforcement, and delamination of FRP laminates), as well as different material types of FRP (CFRP, GFRP, and their hybrid combinations), and FRP strengthening systems (sheets, plates, NSM, and rods) under various loading conditions including ambient, earthquake, and fire. The principles, thumb rules, and findings of this work can be of interest to researchers, practitioners, and students
Effects of BIM in Enhancing Prefabricated Construction
No full textA Master of Science thesis in Civil Engineering by Abdelrahman Mohamed Ezzat Sherra entitled, “Effects of BIM in Enhancing Prefabricated Construction”, submitted in December 2021. Thesis advisor is Dr. Irtishad Ahmad. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).The use of prefabricated construction is not new in the industry. However, recent advances in digital technology, predominantly Building Information Modelling (BIM), has created renewed momentum for extensive use of this method in construction. Prefabricated construction promotes efficiency in the delivery of building construction projects with respect to cost, time, quality, and safety. The main objective of this research study is to investigate the effect of advancements and innovations in the BIM technology and its features on implementation and enhancement of prefabricated construction. This study is aimed at projecting trends, outlook, and the directions in the construction industry as a result of the BIM technology and the prefabrication method of construction. As the extent of use of BIM continues to increase, its impacts on prefabricated construction and their significance in the industry should be investigated. In addition, the industry should be aware of existing issues, problems, and roadblocks in order to effectively use the BIM technology to improve and enhance the method of prefabricated construction. The study is an effort in that direction. It looks into the changes taking place in the global as well as in the UAE construction industry. In addition to the extensive literature survey conducted for this study, a questionnaire survey was conducted in the UAE. Furthermore, a selected group of the UAE construction industry professionals with BIM and prefabrication experience were interviewed for this research. The findings of the research study are presented in the form of guidelines and action steps for improving the effectiveness of prefabricated construction in the UAE as a result of BIM technology. The effectiveness is examined by the measures of major project parameters, namely cost, time, quality, and safety. The specific features of BIM in achieving improvements in cost, time, quality, and safety when prefabrication is used are identified. An actual case study of a recently undertaken construction project, the Dubai Museum of Future, is analyzed in this study to substantiate the main recommendations and illustrate the benefits of BIM in prefabrication projects.College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE
Optimizing the Cleaning Frequency of Solar Photovoltaic (PV) systems Using Numerical Analysis
No full textA Master of Science thesis in Engineering Systems Management by El-Cheikh Amer Kais Kaiss entitled, “Optimizing the Cleaning Frequency of Solar Photovoltaic (PV) systems Using Numerical Analysis”, submitted in November 2021. Thesis advisor is Dr. Noha Hussein. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).There has been a huge growth in the global capacity of solar PV installation to harvest solar energy. However, the efficiency of solar PV systems can be greatly reduced due to dust accumulation/soiling. Cleaning the panels frequently can mitigate the reduction in efficiency of solar PV systems due to dust; however, cleaning the panels too frequently can increase maintenance costs which decreases profitability. Therefore, it is crucial to optimize the cleaning frequency of solar PV systems to maximize its efficiency and power generation while minimizing operational costs. This study aims to determine the optimum cleaning frequency of solar PV system to minimize operational costs and maximize power output. Several factors that influence the dust deposition rate are analyzed through CFD simulations on ANSYS FLUENT. A mathematical model that relates the dust deposition rate to the most significant factors is developed using Minitab software. Subsequently, the developed model is used to determine the decrease in solar PV efficiency due to dust deposition over time. Finally, the cleaning frequency of solar PV panels specific to Sharjah, United Arab Emirates (UAE) is optimized using the Solver Add-in in Microsoft Excel to maximize energy generation and minimize cleaning costs. It was found that the dust diameter, panel tilt angle, and wind speed have the greatest impact on the dust deposition rate. The dust diameter is positively related to dust deposition rate while a negative relationship exists between the wind speed and dust deposition rate. In addition, it was found that the maximum dust deposition rate occurs at a tilt angle of approximately 50 degrees. Furthermore, it was found that the optimum cleaning frequency using manual cleaning method in Sharjah, UAE is every 8 to 9 days. In addition, the optimum cleaning frequency using machinery cleaning method in Sharjah, UAE was shown to be every 3 to 4 days. The results agree well with the results reported in the literature.College of EngineeringDepartment of Industrial EngineeringMaster of Science in Engineering Systems Management (MSESM
Modeling of Anti-cancer Drug Release Kinetics from Liposomes and Micelles: A review
No full textNanocarriers, such as liposomes and micelles, were developed to enhance the delivery of therapeutic drugs to malignant tissues. Internal or external stimuli can be applied to achieve spatiotemporal controlled release from these carriers. This will result in enhancing their therapeutic efficacy while reducing toxicity. Mathematical modeling is used to simulate drug release from nanocarriers; this will facilitate and optimize the development and design of desirable nanocarriers in a systematic manner, rather than a trial-and-error approach. This review summarizes nine mathematical models often used to simulate drug release from nanocarriers and reviews studies which employed these models to simulate drug release from conventional as well as temperature-, pH-, and ultrasound-triggered micelles and liposomes.American University of SharjahAl-Jalila FoundationSheikh Saud bin Saqr Al Qasimi Foundation for Policy ResearchPatient's Friends Committee-SharjahBiosciences and Bioengineering Research InstituteGCC Co-Fund ProgramTakamul ProgramTechnology Innovation Pioneer (TIP) Healthcare AwardsDana Gas Endowed Chair for Chemical Engineerin