AUS Repository (American University of Sharjah)
Not a member yet
2669 research outputs found
Sort by
Maintenance Decisions for Medical Equipment in UAE Medical Facilities
No full textA Master of Science thesis in Engineering Systems Management by Reham Adil Yousif Mohamed Elashi entitled, “Maintenance Decisions for Medical Equipment in UAE Medical Facilities”, submitted in November 2023. Thesis advisor is Dr. Abdulrahim Shamayleh and thesis co-advisor is Dr. Mahmoud Awad. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Medical devices are crucial in the process of preventing, monitoring, diagnosing and treatment of diseases. Healthcare services greatly rely on medical equipment to properly deliver their desired services. Hence, the proper functioning and availability of those medical devices is crucial to healthcare services providers. Proper planned maintenance decisions lead to more cost efficient, reliable and non-disrupted service, particularly with the increased reliance on medical equipment in health care facilities to realize their services. Despite their importance and widespread usage in UAE, there is minimal information on maintenance practices. As such, it is crucial to understand the influential factors and key indicators that would lead to successful equipment maintenance decisions. The objective of this research study is to explore the current medical equipment maintenance practices implemented in the UAE within the medical facilities and explore the pivotal factors in maintenance decisions that would contribute to enhanced equipment performance. A qualitative study employing Confirmatory Factor Analysis (CFA) is carried out to investigate the relationship between various factors and equipment performance indicators. The main research tool used is a survey developed based on reviewed literature and feedback from five subject matter experts. Partial Least Squares Structural Equation Model (PLS-SEM) is applied for data analysis and the subsequent development of the final model. The results suggest that the main influential factors are strategic decisions and infrastructure. Additionally, the results suggest that there is an indirect influence of management on equipment performance. This influence is mediated through management's heightened awareness of maintenance decisions, and their participation in the strategic decisions related to maintenance. Maintenance practices in the UAE show discernible variations, especially with shifts in device functionality. The recommendation is to maintain existing decisions for critical devices while improving maintenance decisions for less critical ones. This involves careful planning of maintenance contracts, inclusive procurement procedures covering the equipment's entire life cycle, and the crucial use of IT tools for monitoring and analyzing performance data to inform corrective actions.College of EngineeringDepartment of Industrial EngineeringMaster of Science in Engineering Systems Management (MSESM
Optimal Assignment of Mobile Charging Stations for On-The-Move Electric Vehicles
No full textA Master of Science thesis in Electrical Engineering by Zakieh Ghassan Hamza entitled, “Optimal Assignment of Mobile Charging Stations for On-The-Move Electric Vehicles”, submitted in April 2023. Thesis advisor is Dr. Ahmed Osman and thesis co-advisor is Dr. Mohamed Hassan. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).lectric vehicles (EVs) are gaining increasing interest due to their zero emissions and relatively reduced running cost. However, the availability of charging energy is a main concern for many EV users. Therefore, a mobile charging station (MCS) facility is a potential solution that helps overcome many of the EV charging issues. With MCSs, EVs can be charged more easily with less waiting time compared with traditional fixed charging stations (FCSs). This thesis proposes a new approach to mobile charging stations for electric vehicles. From the perspective of the MCS operator, the goal is to maximize the revenues by increasing the number of served EVs with high required energy among several requests raised to MCS while maintaining a minimum operation cost throughout the charging service. A mobile charging station operating agency (MCSOA) is proposed for running an assignment and dispatching mechanism (ADM). Considering the randomness of EV charging requests and MCS locations, the MCSOA runs a dynamic optimization problem that is formulated as a mixed integer non-linear programming (MINLP) model to assign the most profitable EVs and dispatch the MCS to the optimal charging location, aiming to maximize the total profits of MCSs. Furthermore, the performance of the proposed ADM mechanism has been simulated using real-world traffic flow data of Dubai and Sharjah – UAE. The performance of the proposed system over different system parameters is studied. Additionally, to improve the effectiveness and validity of this mechanism, the system's performance has been evaluated for some irregular conditions, such as road traffic and unbalanced energy demand over the service area. Furthermore, numerical simulations show that the proposed ADM mechanism increases the system profits besides the number of served EVs in comparison with other EV charging coordination approaches including conventional charging at fixed charging stations (FCS), Nearest-Job-Next assignments (NJN), First Come First Served assignments (FCFS) and Earliest Deadline-First (EDF).College of EngineeringDepartment of Electrical EngineeringMaster of Science in Electrical Engineering (MSEE
Identification and Assessment of Risks and Response Strategies in High-Rise Construction Projects
No full textA Master of Science thesis in Construction Management by Ahmed Magdy Shahin entitled, “Identification and Assessment of Risks and Response Strategies in High-Rise Construction Projects”, submitted in November 2023. Thesis advisor is Dr. Sameh El-Sayegh. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).The construction industry in the United Arab Emirates (UAE) is recognized as one of the most dynamic in the Middle East. This is due to its continuous expansion and the endless investment opportunities it offers. There are various risks that could impact the performance of projects in terms of budget and schedule. This subject has gained attention in research, however there is a notable gap in studying the potential risks in high-rise construction in UAE. This thesis explores risk management in UAE, specifically focusing on the high-rise construction segment. The first objective of this research is to identify the top ten risks in high-rise construction in UAE. The second objective is to empirically assess the impact of the identified risks on project budget and schedule. The third objective of this study is to determine the suitable response strategies to manage the identified risks. The identification of the critical risks was carried out through extensive literature review. These risks were incorporated within a survey questionnaire to evaluate and assess their probability and impact utilizing a Likert scale approach. The survey results were further analysed and the Relative Importance Index (RII) was used to rank the risks based on their impact on budget and schedule. The survey was also utilized to identify the most effective management strategies to control the identified risks. Key risks such as financial constraints including delayed payments and fluctuating material costs emerged as significant concerns. The research findings indicate that the risk of tight schedules holds the highest impact on project duration, with RII of 0.979. In addition, the risk of design changes and variation orders is identified as having the most significant impact on project budgets, bearing an RII of 0.975. The findings highlight the importance of proactive planning and clear contractual frameworks as crucial in managing these risks. The thesis contributes significantly by offering a wide understanding of risk management in the context of UAE's high-rise construction. This research serves as a practical guide, and it offers robust strategies to control and manage risks in this dynamic field.College of EngineeringMultidisciplinary ProgramsMaster of Science in Construction Management (MSCM
Light-Responsive Metal-Organic Frameworks (MOFs) For Doxorubicin Controlled Release
No full textA Master of Science thesis in Biomedical Engineering by Isra Abdelwahab entitled, “Light-Responsive Metal-Organic Frameworks (MOFs) For Doxorubicin Controlled Release”, submitted in April 2023. Thesis advisor is Dr. Rana Sabouni. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).The life cycle of human cells involves growth, divisions, and programmed cell death (apoptosis). However, DNA damage can cause some cells to proliferate uncontrollably, leading to cancer. While chemotherapy is an effective treatment option for cancer, it often has significant side effects. Researchers are exploring novel ways to deliver chemotherapy drugs more effectively while minimizing side effects. One promising method for controlled and targeted drug delivery is the use of stimuli light-responsive nanomaterials. Among the various stimuli-responsive nanomaterials, light mechanisms have shown considerable potential in providing site specific drug delivery. Metal-organic frameworks (MOFs) possess unique physicochemical properties, making them a promising candidate as light-responsive nanocarrier for controlled drug delivery. In this work, we investigated the potential of three MOFs, ZIF-8, Fe-BTC, and MIL-53(Al), as light-responsive nanocarriers for the controlled delivery of doxorubicin (DOX). The MOFs were evaluated for their drug encapsulation and release efficiency. The results showed that ZIF-8 exhibited a high encapsulation efficiency of 87%, and a high drug release efficiency at both pH levels of 5.3 and 7.4. On the other hand, Fe-BTC and MIL-53(Al) exhibited dual responsiveness to pH and light, with the highest release occurring at pH 5.3 when exposed to UV light. The total release efficiency of both systems was significantly higher with UV. Additionally, MIL-53(Al) also showed a seven folds higher drug release efficiency with NIR light at pH 5.3 than the control. The physicochemical properties of MOFs were analyzed using SEM, FTIR BET, and XRD. Furthermore, the in vitro cytotoxicity of the MOFs was tested on HCT 116 colon cancer cells using MTT assays, and the results showed that both MIL-53 (Al) and Fe-BTC were biocompatible up to 200 μg/mL, while ZIF-8 had some cytotoxicity. Also, UV-C light alone did not affect cell viability, however, when combined with DOX-Fe-BTC, the cell viability was reduced to 82.25%, while the combination with DOX-MIL-53(Al) had cell viability of 49.84%, indicating that it is a promising treatment option for cancer.College of EngineeringMultidisciplinary ProgramsMaster of Science in Biomedical Engineering (MSBME
Effect of phospholipid head group on ultrasound‑triggered drug release and cellular uptake of immunoliposomes
No full textLiposomes are the most successful nanoparticles used to date to load and deliver chemotherapeutic agents to cancer cells. They are nano-sized vesicles made up of phospholipids, and targeting moieties can be added to their surfaces for the active targeting of specific tumors. Furthermore, Ultrasound can be used to trigger the release of the loaded drugs by disturbing their phospholipid bilayer structure. In this study, we have prepared pegylated liposomes using four types of phospholipids with similar saturated hydrocarbon tails including a phospholipid with no head group attached to the phosphate head (DPPA) and three other phospholipids with different head groups attached to their phosphate heads (DPPC, DPPE and DPPG). The prepared liposomes were conjugated to the monoclonal antibody trastuzumab (TRA) to target the human epidermal growth factor receptor 2 (HER2) overexpressed on HER2-positive cancer cells (HER2+). We have compared the response of the different formulations of liposomes when triggered with low-frequency ultrasound (LFUS) and their cellular uptake by the cancer cells. The results showed that the different formulations had similar size, polydispersity, and stability. TRA-conjugated DPPC liposomes showed the highest sensitivity to LFUS. On the other hand, incubating the cancer cells with TRA-conjugated DPPA liposomes triggered with LFUS showed the highest uptake of the loaded calcein by the HER2+ cells.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 SciencesFriends of Cancer Patients (FoCP)Dana Gas Endowed Chair for Chemical Engineerin
Recent Breakthroughs in Using Quantum Dots for Cancer Imaging and Drug Delivery Purposes
No full textCancer is one of the leading causes of death worldwide. Because each person’s cancer may be unique, diagnosing and treating cancer is challenging. Advances in nanomedicine have made it possible to detect tumors and quickly investigate tumor cells at a cellular level in contrast to prior diagnostic techniques. Quantum dots (QDs) are functional nanoparticles reported to be useful for diagnosis. QDs are semiconducting tiny nanocrystals, 2–10 nm in diameter, with exceptional and useful optoelectronic properties that can be tailored to sensitively report on their environment. This review highlights these exceptional semiconducting QDs and their properties and synthesis methods when used in cancer diagnostics. The conjugation of reporting or binding molecules to the QD surface is discussed. This review summarizes the most recent advances in using QDs for in vitro imaging, in vivo imaging, and targeted drug delivery platforms in cancer applications.American University of SharjahAl-Jalila FoundationAl Qasimi FoundationPatient’s Friends Committee-SharjahGCC Co-Fund ProgramTakamul programSheikh Hamdan Award for Medical SciencesFriends of Cancer Patients (FoCP)Dana Gas Endowed Chair for Chemical EngineeringBiosciences and Bioengineering Research InstituteTechnology Innovation Pioneer (TIP) Healthcare Award
Experimental Characterization of Electrostatic MEMS Resonators for Sensing Applications
No full textA Master of Science thesis in Mechatronics Engineering by Basil Yousef Ahmad Alattar entitled, “Experimental Characterization of Electrostatic MEMS Resonators for Sensing Applications”, submitted in April 2023. Thesis advisor is Dr. Mehdi Ghommem. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).In this Thesis, we present an experimental technique to detect the onset of bifurcation and measure the extent of hysteresis in electrostatic MEMS resonators. The device- under-test comprises a microcantilever beam actuated via a side electrode placed inside a vacuum chamber to control the squeeze-film damping. The beam vibrations result in varying the resonator’s capacitance, therefore inducing a current that can be measured and used for characterization and performance analysis. The motion-induced current is measured, and its harmonics are extracted using a lock-in amplifier. Locking on the third harmonic of the induced current enables us to bypass parasitic capacitance and extract a signal directly related to the resonator motions. We show that this signal can be used to investigate the nonlinear dynamic behaviour of MEMS resonators undergoing large motions. Specifically, our experiments demonstrate our technique's ability to detect various bifurcations, to track the onset of hysteresis, and to measure the hysteresis bandwidth. We also use our technique to analyse the quantitative relationships between the actuation voltage, the location of the bifurcation point, and the hysteretic bandwidth. We show that our technique can be used to generate the calibration curves for inertial MEMS sensors. Finally, we compare the use of two measurement techniques for the nonlinear analysis of electrostatic MEMS resonators: optical vibrometry and motion-induced current. We demonstrate the capability of the two approaches to detect nonlinear features in the motions of the resonator when subjected to high excitation voltages. We also show that the measurements obtained from both techniques for the onset of multivaluedness, cyclic-fold bifurcations, and hysteresis are in close agreement.College of EngineeringMultidisciplinary ProgramsMaster of Science in Mechatronics Engineering (MSMTR
A Low Cost, Large Bandwidth Patch Antenna design for utilization in Frequency Diverse Arrays
No full textA Master of Science thesis in Electrical Engineering by Usama Mozammil Iqbal entitled, “A Low Cost, Large Bandwidth Patch Antenna design for utilization in Frequency Diverse Arrays”, submitted in June 2023. Thesis advisor is Dr. Lutfi Albasha and thesis co-advisor is Dr. Hasan Mir. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Low-power Internet of Things (IoT) and wireless charging applications have expedited a rise in Wireless Power Transfer (WPT) technologies. WPT methods are divided into two main categories: near-field and far-field. Far-field-based techniques that employ electromagnetic (EM) radiation are seeing increased use in wireless charging appliances due to their improved power transfer efficiency (PTE) over long distances. Beamforming is one of the main signal-focusing techniques to steer signal intensity electrically in the intended direction. This is achieved by placing multiple transmitting/receiving antennas as a phased array and providing each antenna with a signal of the same frequency but a different phase offset. However, beamforming makes it possible to steer the signal as a function of the scanning angle and not the signal’s range. Recently, a range-angle-based beamforming technique called the Frequency Diverse Array (FDA) has been proposed to circumvent the general inefficiencies of WPT. FDA-based systems provide each antenna element with a different phase offset and introduce a slight frequency offset to each element. The resolution of the steered beam can be improved by increasing the number of antenna elements and operating the system with a large frequency bandwidth. This thesis proposes an improved low-profile, high bandwidth inset-fed microstrip patch antenna architecture incorporated as the front end of a WPT transmitter. The antenna was designed to operate at a frequency of 5.8GHz with dimensions of 21mm x 25 mm x 0.8 mm. Inserting parasitic patches and shorting vias improved the antenna’s operational bandwidth from 79MHz to 230MHz. Moreover, the reflection coefficient was also measured to be -34.9 dB, which amounts to almost 98% of the power transferred from the source to the antenna. Finally, the antenna was manufactured through the Printed Circuit Board (PCB) machine in the Electronics lab at the American University of Sharjah at a relatively low cost.College of EngineeringDepartment of Electrical EngineeringMaster of Science in Electrical Engineering (MSEE
Spatial Distribution and Abundance of Emerging Microplastics Pollutants in Groundwater of UAE
No full textA Master of Science thesis in Civil Engineering by Bushra Tatan entitled, “Spatial Distribution and Abundance of Emerging Microplastics Pollutants in Groundwater of UAE”, submitted in June 2023. Thesis advisor is Dr. Md. Mortula and thesis co-advisor is Dr. Tarig Ali. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Global production of plastics is expected to keep on increasing as consumption increases. Plastics are known to undergo disintegration in the environment resulting in the formation of microplastics. Microplastics pollution is growing, but few studies have considered assessment of contamination in groundwater. This might be due to lack of monitoring groundwater for microplastics contamination. However, groundwater is a common source of water in various industries globally. In the UAE, more than half of the water supply is from groundwater, specifically in the agricultural industries. This study aimed to investigate microplastics contamination in groundwater in the UAE. The study identified 30 groundwater boreholes in the Rahmaniya, Bedee, and Falah regions of Sharjah, UAE, from which samples were collected. To prepare the samples, a series of pretreatment procedures involving 30% hydrogen peroxide, density separation, and extraction filters were employed. Microplastics were subsequently detected using a microscope with 40x magnification, revealing the presence of microplastics in the water of 11 boreholes in Rahmaniya, ranging from 12 to 235 n/L, respectively. In the Falah area, contamination was observed in two boreholes, with 56 and 41 n/L, respectively, while no contamination was found in the Bedee area. Characterization of microplastics was conducted using ATR-FTIR analysis, which has successfully matched the obtained spectra with polyethylene terephthalate, polyethylene, and polypropylene for 10 samples. To examine the spatial variability and clustering of microplastics, a raster layer was created in GIS and used to perform hotspot analysis. The findings demonstrated a significant hotspot in the Rahmaniya area, indicating concentrated microplastics contamination. Moreover, potential sources of contamination were investigated based on land use and location, and three remote sensing-based indices, which are the Normalized Difference Water Index (NDWI), Normalized Difference Vegetation Index (NDVI) and moisture index. This has helped in the identification of industrial areas, the Sajaa landfill, Bedee Farmland, and the water dump lagoon as potential sources of contamination.College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE