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Power System Transient Stability Assessment Based on Machine Learning Algorithms and Grid Topology
No full textThis work employs machine learning methods to develop and test a technique for dynamic stability analysis of the mathematical model of a power system. A distinctive feature of the proposed method is the absence of a priori parameters of the power system model. Thus, the adaptability of the dynamic stability assessment is achieved. The selected research topic relates to the issue of changing the structure and parameters of modern power systems. The key features of modern power systems include the following: decreased total inertia caused by integration of renewable sources energy, stricter requirements for emergency control accuracy, highly digitized operation and control of power systems, and high volumes of data that describe power system operation. Arranging emergency control in these new conditions is one of the prominent problems in modern power systems. In this study, the emergency control algorithms based on ensemble machine learning algorithms (XGBoost and Random Forest) were developed for a low-inertia power system. Transient stability of a power system was analyzed as the base function. Features of transmission line maintenance were used to increase accuracy of estimation. Algorithms were tested using the test power system IEEE39. In the case of the test sample, accuracy of instability classification for XGBoost was 91.5%, while that for Random Forest was 81.6%. The accuracy of algorithms increased by 10.9% and 1.5%, respectively, when the topology of the power system was taken into account.American University of Sharja
Self-Consolidated Concrete-to-Conductive Concrete Interface: Assessment of Bond Strength and Mechanical Properties
No full textIn this paper, the mechanical properties and bond strength of composite samples that consist of a conductive concrete (CC) layer and a self-consolidated concrete (SCC) layer are investigated. The bond strength study includes two parameters: (1) surface preparation and (2) casting and testing directions. The surface preparation study shows that, compared to the other methods in this study, the shear key method is the most suitable surface preparation method to fully utilize the CC in a composite. Moreover, the casting direction study reveals that the strength is heavily dependent on the type of test used along with CC’s layer positioning. The flexural strength study confirms that positioning the CC mix in the tensile region is beneficial since it can increase the flexural strength of a structure because of the hybrid steel fibers included in the mixture. Finally, different codes/specifications and published theoretical results are used to predict the CC’s mechanical properties, and the predictions are not as accurate as the SCC predictions, which can be attributed to the presence of conductive fillers in the CC mix.American University of SharjahOpen Access Program from the American University of Sharja
Impact of COVID-19 restrictions on health and well-being in the United Arab Emirates
No full textBackground: Restrictions during the COVID-19 pandemic are thought to have impacted both the physical health and well-being of individuals where lockdown was applied. The United Arab Emirates (UAE) was one of the leading countries in implementing the international guidelines to limit the intensely contagious nature of the outbreak. Aim: To identify the impact of COVID-19 on changes to exercise and general physical activity habits, changes to the consumption of various foods and potential weight gain, as well as any differences in smoking habits among individuals residing in the UAE during the COVID-19 quarantine. Methods: This is a cross-sectional analytical study that used a quantitative electronic questionnaire sent by the Ministry of Health and Prevention to individuals on its platform in order to collect data on the physical health and well-being of a UAE sample population. A total of 2,362 responses were received to specific questions on physical activity, eating habits, and tobacco use for the period before, during, and after the COVID-19 lockdown. Descriptive statistical analysis was used to display the sample’s demographic data and the changes in physical health and well-being. Paired t-test was used to show the changes in dietary habits. Results: This study reveals concerning changes in health risk behaviors during the COVID-19 lockdown in the UAE. Physical activity levels declined across mild, moderate and vigorous ranges in most participants. Alarmingly, sedentary behavior dramatically increased with 71% of participants spending an average of 4–8 h per day sitting and over 54% of participants spending more than 4 h watching TV on an average day during lockdown. Fast-food consumption and snacking rose, hence weight gain was observed in over 53% of participants. Smoking habits, especially among cigarette smokers, may have worsened, with 45.2% reporting an increase in cigarette smoking, 16.8% declaring an increase in shisha smoking and 35.3% reporting an increase in smoking other tobacco products. These unfavorable behaviors during confinement could have serious long-term health consequences. Conclusion: This study demonstrates that long periods of home quarantine may have led to unhealthy consequences that increase the risk of developing disease. This study therefore aims to highlight these health impacts, and recommend strategies and policies that can encourage healthy habits.Emirates Health Service
Shear Behavior of One-Way Reinforced Concrete Hollow Slabs Voided with PET Void Formers
No full textA Master of Science thesis in Civil Engineering by Haider H. Hasan entitled, “Shear Behavior of One-Way Reinforced Concrete Hollow Slabs Voided with PET Void Formers”, submitted in May 2023. Thesis advisor is Dr. Sami Tabsh. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).In residential reinforced concrete structures, the slab constitutes the largest concrete volume. Reducing its concrete content leads to significant cost savings and environmental benefits. Furthermore, Polyethylene Terephthalate (PET) bottles, which account for approximately 22% of all plastic packaging products globally, are non-biodegradable and release toxic chemicals when buried in landfills or incinerated. This research aimed to evaluate the structural and construction feasibility of utilizing PET bottles as void formers in slabs. Previous studies lacked comprehensive investigations into the use of PET bottles as void formers and their effects on slab’s shear performance. To accomplish this study’s objectives, 13 full-scale, shear critical reinforced concrete one-way slabs with a width of 600 mm were tested under a 3-point loading configuration at AUS. The experimental program featured varying concrete compressive strengths (30 and 50 MPa), steel reinforcement ratios (0.66, 0.88, and 1.4%), presence of top steel layer, slab thicknesses (180 and 230 mm), shear span-to-effective depth ratios (1.49, 2.97, and 3.95), and void percentages (0, 17, 22, and 29%). In addition to the experimental investigation, theoretical studies were conducted to predict the shear strength using North American and European structural design codes. A novel analytical shear strength model was developed, and its accuracy was validated using a dataset of 55 slabs from various researchers. The findings indicated that voided to solid shear strength ratios ranged between 0.61 and 1.04, while shear stress ratios varied between 0.82 and 1.29. Voided slabs demonstrated comparable overall behavior without displaying drastic decrease in ductility. The compressive strength and reinforcement ratio had less pronounced effect on increasing the strength of voided slabs. Void percentage alone was not a suitable metric for evaluating the shear strength, as beyond a certain percentage, the influence of void area on shear strength diminished. The proposed model prediction ratios were within 10% of the experimental results, indicating good agreement and outperforming design codes like ACI 318, BS 8110, and Eurocode 2 prediction ratios, which deviated by more than 100%. By optimizing design parameters and employing precise analysis procedures, the performance of voided slabs can be enhanced, resulting in efficient and cost-effective structures.College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE
Ultrasound Mediated Release of Cetuximab-Conjugated Liposomes Targeting Brain Cancers
No full textA Master of Science thesis in Biomedical Engineering by Richu Raju Richi entitled, “Ultrasound Mediated Release of Cetuximab-Conjugated Liposomes Targeting Brain Cancers”, submitted in June 2023. Thesis advisor is Dr. Ghaleb Husseini. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).College of EngineeringMultidisciplinary ProgramsMaster of Science in Biomedical Engineering (MSBME
A Water-Energy Nexus Approach for the Co-optimization of the Electrical and Water Systems
No full textA Master of Science thesis in Electrical Engineering by Mennatalla Ahmed Elbalki entitled, “A Water-Energy Nexus Approach for the Co-optimization of the Electrical and Water Systems”, submitted in May 2023. Thesis advisor is Dr. Mostafa Shaaban and thesis co-advisor is Dr. Ahmed Osman. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Water and electricity are two essential and critical needs for living; however, water scarcity and uncertainty are becoming more prominent. Water networks are energy-demanding industries where a significant amount of electricity is consumed in various water processes. Also, thermal desalination systems are usually a part of a cogeneration process, which cogenerates electricity and freshwater. Therefore, water and electrical networks can't be entirely independent by which a more integrated approach, Water-Energy Nexus (WEN), is developed. A WEN is the basis of a smart city where water and electrical networks are interconnected and integrated by implementing efficient management strategies. Accordingly, this study develops a co-optimization model for the design and operation of the integrated power and water systems. The proposed co-optimization model minimizes the total annual cost of the micro-WEN system while capturing its optimum design values and operating conditions and meeting the electrical and water demands. For a smart grid, three main characteristics are considered to enhance its efficiency and reliability: Integrating distributed energy resources, including renewable resources, grid operations, and resources optimization, and utilizing advanced electricity storage technologies. Improving the efficiency and reliability of a water network can involve a variety of measures: Improving the pump station design, system configuration, and valve distribution, installing variable speed drives (VSDs) for pumps, and including water storage tanks. The design and operational problems are formulated as non-linear programming (NLP) in General Algebraic Modelling System (GAMS) environment. This work presents a plan for the transition from thermal desalination to RO desalination in UAE, where electricity and water production are decoupled to address the problem of operating UAE's power plants during the winter at low efficiency to be able to meet the water demand. The results show that the optimal design of the cogeneration unit has a power generation capacity of 150 MW and a water production capacity of 145 mᵌ/h to meet the electrical and water demands at a minimum total annual cost. Moreover, the simulation results assert that the co-optimization model provides a reduction in the total operational cost of 1.23% and 26.7% with the integration of PVs and shifting to RO with PV, respectively.College of EngineeringDepartment of Electrical EngineeringMaster of Science in Electrical Engineering (MSEE
Incorporating nanoparticles in 3D printed scaffolds for bone cancer therapy
No full textThe low occurrence rate of bone cancer contributes to delayed diagnosis and treatment; in addition, the surgical resection of bone tumors can cause significant bone defects, further hindering the effective treatment of the disease. 3D printing can help overcome some of these limitations by enabling the design and fabrication of innovative scaffolds loaded with chemotherapeutics and growth factors, stimulating bone regeneration, and delivering targeted cancer treatment. Moreover, advancements in nanotechnology have opened up new possibilities for bone tissue engineering. Nanoparticles (NPs) possess size-dependent physicochemical properties. NPs can also be designed to respond to specific stimuli enhancing localized drug delivery. These unique properties can be harnessed by embedding NPs in 3D-printed scaffolds to develop multifunctional bone scaffolds with enhanced mechanical properties and drug delivery capabilities. This review evaluates the impact of incorporating NPs in 3D-printed scaffolds on bone cancer therapy and bone regeneration. First, various 3D printing techniques employed in the biomedical field are presented and explained. The article then highlights notable achievements by researchers in this area. Finally, the review discusses the current obstacles facing this technology and how they can be addressed to enable translation into clinics.American University of SharjahAl-Jalila FoundationAl Qasimi FoundationPatient’s Friends Committee-SharjahBiosciences and Bioengineering Research InstituteGCC Co-Fund ProgramTakamul programTechnology Innovation Pioneer (TIP) Healthcare AwardsSheikh Hamdan Award for Medical SciencesDana Gas Endowed Chair for Chemical Engineerin
Hydrogen liquefaction and storage: Recent progress and perspectives
No full textThe global energy sector accounts for ∼75% of total greenhouse gas (GHG) emissions. Low-carbon energy carriers, such as hydrogen, are seen as necessary to enable an energy transition away from the current fossil-derived energy paradigm. Thus, the hydrogen economy concept is a key part of decarbonizing the global energy system. Hydrogen storage and transport are two of key elements of hydrogen economy. Hydrogen can be stored in various forms, including its gaseous, liquid, and solid states, as well as derived chemical molecules. Among these, liquid hydrogen, due to its high energy density, ambient storage pressure, high hydrogen purity (no contamination risks), and mature technology (stationary liquid hydrogen storage), is suitable for the transport of large-volumes of hydrogen over long distances and has gained increased attention in recent years. However, there are critical obstacles to the development of liquid hydrogen systems, namely an energy intensive liquefaction process (∼13.8 kWh/kgLH2) and high hydrogen boil-off losses (liquid hydrogen evaporation during storage, 1–5% per day). This review focuses on the current state of technology development related to the liquid hydrogen supply chain. Hydrogen liquefaction, cryogenic storage technologies, liquid hydrogen transmission methods and liquid hydrogen regasification processes are discussed in terms of current industrial applications and underlying technologies to understand the drivers and barriers for liquid hydrogen to become a commercially viable part of the emerging global hydrogen economy. A key finding of this technical review is that liquid hydrogen can play an important role in the hydrogen economy - as long as necessary technological transport and storage innovations are achieved in parallel to technology demonstrations and market development efforts by countries committed liquid hydrogen as part of their hydrogen strategies.Engineering and Physical Sciences Research Council (EPSRC)UK Industrial Decarbonisation Research and Innovation Centre (IDRIC)European Union's Horizon 2020 research and innovation programm
Image-CNN Based Process Control of Profile
No full textA Master of Science thesis in Engineering Systems Management by Zeinab Jihad Zeinab entitled, “Image-CNN Based Process Control of Profile”, submitted in December 2023. Thesis advisor is Dr. Hussam Alshraideh. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).For quality inspection purpose, control charts have been widely adopted successfully in manufacturing industry throughout the years. Smart Manufacturing (SM) has emerged as a key concept for articulating the ultimate goal of manufacturing digitization as a result of the advancement of technologies like Artificial Intelligence (AI). For SM, an automatic process that can handle massive amounts of data from ongoing, concurrent processes is needed. In comparison, recognizing patterns in data and defect classification present challenges for typical control charts. To resolve these problems, Deep Learning (DL) algorithms proved to be an effective analytical tool that can aid in fault detection. The early classification of flaws and defects in machinery or manufacturing processes can be easily achieved by a detection monitoring system capability. In this thesis, a DL-based framework for monitoring profile generating processes is presented. The framework relies on the presentation of profile time series data as two-dimensional images, for which four transformation algorithms were explored including Gramian Angular Field (GAF), Markov Transition Field (MTF), and Recurrence Plots (RP). Proposed framework was evaluated through two case studies. In the first one, a tapping process is considered while a 3D printing process is considered in the second case. Proposed model achieved an accuracy level of 91.6% for the tapping dataset outperforming previous model performance reported in the literature of 84.04%. Similarly, the model showed an improved performance level over existing literature for the 3D printing process data with accuracy levels of 96.6% and 92.6% for the small and large versions of the data, respectively. Our proposed framework provides an automatic feature extraction step as it relies on DL technology providing a major advantage over existing models in the literature that assume a preexisting set of features to be used.College of EngineeringDepartment of Industrial EngineeringMaster of Science in Engineering Systems Management (MSESM