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Ultrasound-responsive Nanocarriers in Cancer Treatment: a review
No full textThe safe and effective delivery of anticancer agents to diseased tissues is one of the significant challenges in cancer therapy. Conventional anticancer agents are generally cytotoxins with poor pharmacokinetics and bioavailability. Nanocarriers are nanosized particles designed to the selectivity of anti-cancer drugs and genes transport to tumors. They are small enough to extravasate into solid tumors where they slowly release their therapeutic load by passive leakage or by biodegradation. Using smart nanocarriers, the rate of release of the entrapped therapeutic(s) can be increased, and greater exposure of the tumor cells to the therapeutics can be achieved when the nanocarriers are exposed to certain internally (enzymes, pH and temperature) or externally applied (light, magnetic field, and ultrasound) stimuli that trigger the release of their load in a safe and controlled manner, spatially and temporally. This review gives a comprehensive overview of recent research findings on the different types of stimuli-responsive nanocarriers and their application in cancer treatment, with a particular focus on ultrasound.American University of SharjahAl-Jalila FoundationAl Qasimi FoundationPatient's Friends Committee-SharjahBiosciences and Bioengineering Research InstituteGCC Co-Fund ProgramTakamul programTechnology Innovation Pioneer (TIP) Healthcare AwardsDana Gas Endowed Chair for Chemical Engineerin
Teachers’ Perspectives on Motivational Challenges and Strategies in L2 Writing Classes at Higher Education Institutions in the UAE
No full textDespite the wealth of research on writing techniques as well as second language (L2) motivation, research on writing motivation and motivational strategies remain underexplored (Bruning & Horn, 2000; Lee et al., 2018). Even the limited research on writing motivation focuses on exploring students’ views, paying little attention to teachers’ perspectives. To fill this important gap, this study investigates how teachers perceive their students’ writing motivation and the strategies they employ to enhance this motivation. Semi-structured interviews were used to collect qualitative data from four English writing instructors at three private universities in the UAE. Findings show that most students experience low levels of writing motivation. Instructors report encountering several student motivational challenges related to student intrinsic motivation, cost of writing, value of writing, and self-efficacy and expectancy. To address these motivational issues, the instructors ensure providing a pleasant and supportive atmosphere, stimulating and enjoyable writing, effective teaching strategies, autonomous learning and constructive feedback. More L2 motivation research should be done in writing contexts, considering teachers’ experiences in dealing with the complexities they encounter in their classrooms. Teachers’ perspectives and practices will provide a broader picture of learner motivation, indicate where support is needed, and become the base for new professional development experiences
Virtualizing and Scheduling FPGA Resources in Cloud Computing Datacenters
No full textA Master of Science thesis in Computer Engineering by Abid Farhan entitled, “Virtualizing and Scheduling FPGA Resources in Cloud Computing Datacenters”, submitted in April 2021. Thesis advisor is Dr. Assim Sagahyroon and thesis co-advisor Dr. Raafat Aburukba. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Cloud service providers are consistently leveraging their computing infrastructures by adding reconfigurable hardware platforms such as field-programmable gate arrays (FPGAs) to their existing infrastructures. Adding FPGAs to a cloud environment involves non-trivial challenges. The first challenge is the virtualization of FPGAs in order to enable FPGAs as cloud resources. Since there does not exist a standard virtualization framework, there is a need to devise an efficient framework for virtualizing FPGAs. Moreover, FPGA resources are used in conjunction with central processing units (CPUs) and graphics processing units (GPUs) to accelerate the execution of different tasks. Therefore, to gain the benefits of these powerful accelerating platforms, the second challenge is to optimize the allocation of a batch of tasks to minimize their makespan. Furthermore, the third challenge is for cloud providers to be able to quantify the performance of the various policies implemented in their cloud datacenters. In this work, an FPGA virtualization framework is proposed to abstract physical FPGAs into virtual pools of FPGA resources. Next, an integer linear programming (ILP) model is proposed to optimize the allocation of FPGA resources to cloud tasks requiring acceleration. Preliminary attempts to validate the model indicate that an optimal solution, which is the minimum makespan, is obtained using an exact solution method. Next, a simulated annealing (SA) metaheuristic is developed not only to achieve gains in performance compared to the exact method, but also scale up and handle larger datasets while providing near-optimal solutions. Experimental results show that SA has reduced the makespan of a large dataset with 1000 tasks and 100 resources by up to 30% when compared to first-come-first-serve (FCFS) and shortest-deadline-first (SDF) algorithms. Lastly, in order to quantify the performance of FPGA-enabled cloud datacenters, an existing cloud simulator named CloudSim is extended to enable FPGA as a resource in its environment. The proposed virtualization framework and the SA scheduler are integrated into the environment. Simulation results show that execution time of tasks is reduced by up to 78% when FPGA accelerators are used.College of EngineeringDepartment of Computer Science and EngineeringMaster of Science in Computer Engineering (MSCoE
Mechanical Properties of Strengthening 5083-H111 Aluminum Alloy Plates at Elevated Temperatures
No full textThe use of aluminum alloys for external strengthening of reinforced concrete (RC) beams has been capturing research interest. Exposure to harsh environmental conditions can severely impact the strengthening efficiency. This works aims to investigate the degradation in the mechanical properties of aluminum alloy AA 5083 plates when exposed to temperatures ranging from 25 to 300 °C. Quasi-static Isothermal tensile experiments were conducted at different temperatures. It was observed from the experimental results that the yield strength remained constant in the temperature range of 25–150 °C before starting to drop beyond 150 °C, with a total reduction of ≈ 40% at 300 °C. The elastic modulus was temperature sensitive with about 25% reduction at 200 °C before experiencing a significant and pronounced reduction at 300 °C. The percentage drops in stiffness and yield strength at 300 °C were 62.8% and 38%, respectively. In addition, the Mechanical Threshold Strength Model (MTS) parameters were established to capture the yield strength temperature dependence. Two analytical models were developed based on the experimental results. Both models can reasonably predict the elastic modulus and yield strength of AA 5083 plates as a function of temperature. It was concluded that AA plates should be properly insulated when used as externally bonded reinforcement to strengthen RC beams.American University of Sharja
Design and Performance Analysis of Misalignment Tolerant Charging Coils for Wireless Electric Vehicle Charging Systems
Get PDFn order to design a high efficiency Wireless Electric Vehicle Charging (WEVC) system, the design of the different system components needs to be optimized, particularly the design of a high-coupling, misalignment-tolerant inductive link (IL), comprising primary and secondary charging coils. Different coil geometries can be utilized for the primary and the secondary sides, each with a set of advantages and drawbacks in terms of weight, cost, coupling at perfect alignment and coupling at lateral misalignments. In this work, a Finite Element Method (FEM)-based systematic approach for the design of double-D (DD) charging coils is presented in detail. In particular, this paper studies the effect of different coil parameters, namely the number of turns and the turn-to-turn spacing, on the coupling performance of the IL at perfect alignment and at ±200 mm lateral misalignment, given a set of space constraints. The proposed design is verified by an experimental prototype to validate the accuracy of the FEM model and the simulation results. Accordingly, FEM simulations are utilized to compare the performance of rectangular, DD and DDQ coils. The FEM results prove the importance of utilizing an additional quadrature coil on the secondary side, despite the added weight and cost, to further improve the misalignment tolerance of the proposed inductive link design.American University of SharjahSharjah Research Academy (SRA
Microwave Imaging System for Non-Metallics Inspection in the Oil and Gas Industry
No full textA Master of Science thesis in Electrical Engineering by Mohammad Abu Laila entitled, “Microwave Imaging System for Non-Metallics Inspection in the Oil and Gas Industry”, submitted in September 2021. Thesis advisor is Dr. Nasser Qaddoumi and thesis co-advisor is Dr. Amer Zakaria. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).The increased demand for energy in the modern industrialized world pushed towards the search for suitable alternatives to existing technologies and materials used in the oil and gas industry. The use of non-metallics components in the oil and gas industry has grown in popularity in recent years for their durability and light-weightiness. These components may fail in many predictable and unpredictable ways in-service or due to manufacturing errors. Since these components are being used for sensitive applications, there is an increasing demand for suitable and accurate inspection and evaluation techniques of such components. Many non-destructive testing techniques have been developed in the past. However, such techniques suffer from significant limitations, including low image quality, slow response, and physical bulkiness. One of the most reliable and well-tested methods is the near-field microwave scanning system, using various near-field electromagnetic probes, e.g., rectangular and circular waveguides. This thesis proposes the enhancements of the imaging capabilities of rectangular waveguides microwave systems using deconvolution methods involving a function called the point spread function. The electric and magnetic field distributions are derived and solved in the near-field region of rectangular waveguides to derive the point spread function. In addition, formulas for the scattered electric and magnetic fields are derived and simplified. These results are used to derive a formula for the point spread function analytically. The point spread function is used for the deconvolution process on scanned images from a microwave scanning system. This process is tested on various simulations and reproductions of real-world defects. The deconvolution process is found to increase the accuracy of the reconstructed images compared to the actual defects. In addition, there are very noticeable improvements in the resolution of imaging systems, increasing their ability to distinguish closely-spaced defects.College of EngineeringDepartment of Electrical EngineeringMaster of Science in Electrical Engineering (MSEE
Development of a Flexible Framework Multi-Design Optimization Scheme for a Hand Launched Fuel Cell-Powered UAV
No full textThis paper presents different methods for the design of a hand-launchable, fixed wing, fuel cell-powered unmanned aerial vehicle (UAV) to maximize flight endurance during steady level flight missions. The proposed design methods include the development of physical models for different propulsion system components. The performance characteristics of the aircraft are modeled through empirical contributing analyses in which each analysis corresponds to an aircraft subsystem. The contributing analyses are collected to form a design structure matrix which is included into a multi-disciplinary analysis to solve for the design variables over a defined design space. The optimal solution is found using a comprehensive optimization tool developed for long endurance flight missions. Optimization results showed a significant improvement in UAV flight endurance that reached up to 475 min with take-off ratio equals to 59 min/kg. Wind tunnel and bench-top tests and HiL simulation tests are performed to validate the results obtained from the optimization tools. Validated optimization results showed an increase of the overall UAV flight endurance by 19.4% compared to classical approaches in design methods.American University of Sharja
Flexural Behavior of Concrete Beams Reinforced for Shear with Steel Welded Wire Fabric
No full textA Master of Science thesis in Civil Engineering by Abdulaziz M. Younes entitled, “Flexural Behavior of Concrete Beams Reinforced for Shear with Steel Welded Wire Fabric”, submitted in July 2021. Thesis advisor is Dr. Sami Tabsh. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Past studies have shown that welded wire fabric (WWF) can be used as an effective alternative to stirrups in resisting shear in reinforced concrete (RC) beams. Such a form of reinforcement reduces the time required to assemble the steel cage and eliminates anomalies in the fabrication and placement of the stirrups. In this study, the flexural behavior of RC beams transversely reinforced with closed steel cages made by cold-forming WWF sheets is investigated. To accomplish the goals of the study, twenty-three 2000 mm long beams with 200 mm x 300 mm cross-section are tested under two-point load configuration with consideration of different wire diameters (4, 6, and 8 mm), grid openings (25, 50, and 100 mm), concrete compressive strengths (30 and 35 MPa), and longitudinal steel reinforcement ratios (about 0.77% and 1.92%). The specimens are provided with linear variable differential transformers and strain gauges and tested inside a universal test machine. A comparison between the test results of WWF reinforced beams and their equivalent stirrup reinforced beams is carried out for benchmarking purposes. The experimental study was accompanied by a theoretical component utilizing the flexural design provisions in ACI 318 concrete design code. In general, findings of the study demonstrated that WWF reinforced beams possess on average 2% higher stiffness at service load level, 18 % more bending moment capacity, 19% lower ductility, and 4% extra residual capacity than corresponding stirrups reinforced beams having the same volumetric ratio of transverse steel. The use of WWF with a small grid opening is not essential because reasonable confinement can be obtained by WWF with a grid opening as large as 100 mm, which will ease any concerns about concrete infiltration between the wire reinforcement of the WWF. The average experimental-to-predicted flexural capacity of concrete beams enclosed with WWF is equal to 1.0 when calculated using the actual (not nominal) material properties; thus, the ACI 318 code can be reliably used to predict the bending moment capacity of such beams. The study recommends providing longitudinal reinforcement in the form of rebars in concrete beams containing WWF in order to maintain a reasonable level of flexural ductility.College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE
Machine learning and structural health monitoring overview with emerging technology and high-dimensional data source highlights
No full textConventional damage detection techniques are gradually being replaced by state-of-the-art smart monitoring and decision-making solutions. Near real-time and online damage assessment in structural health monitoring (SHM) systems is a promising transition toward bridging the gaps between the past’s applicative inefficiencies and the emerging technologies of the future. In the age of the smart city, Internet of Things (IoT), and big data analytics, the complex nature of data-driven civil infrastructures monitoring frameworks has not been fully matured. Machine learning (ML) algorithms are thus providing the necessary tools to augment the capabilities of SHM systems and provide intelligent solutions for the challenges of the past. This article aims to clarify and review the ML frontiers involved in modern SHM systems. A detailed analysis of the ML pipelines is provided, and the in-demand methods and algorithms are summarized in augmentative tables and figures. Connecting the ubiquitous sensing and big data processing of critical information in infrastructures through the IoT paradigm is the future of SHM systems. In line with these digital advancements, considering the next-generation SHM and ML combinations, recent breakthroughs in (1) mobile device-assisted, (2) unmanned aerial vehicles, (3) virtual/augmented reality, and (4) digital twins are discussed at length. Finally, the current and future challenges and open research issues in SHM-ML conjunction are examined. The roadmap of utilizing emerging technologies within ML-engaged SHM is still in its infancy; thus, the article offers an outlook on the future of monitoring systems in assessing civil infrastructure integrity.Horizon 2020 Project TURNkeyAmerican University of Sharja
Mechanical and Electrical Properties Evaluation of Conductive Concrete Matrix
No full textA Master of Science thesis in Civil Engineering by Mohammed Adnan EL Afandi entitled, “Mechanical and Electrical Properties Evaluation of Conductive Concrete Matrix”, submitted in June 2021. Thesis advisor is Dr. Sherif Yehia and thesis co-advisors are Dr. Taha Landolsi and Dr. Nasser Qaddoumi. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Conductive concrete is a material that can conduct electricity through conductive fillers, commonly made from graphite, carbons, and steel fibers. Thanks to its conductive nature, this type of concrete can be utilized in multiple applications such as deicing, electromagnetic shielding, and traffic monitoring. However, issues can arise when adding conductive concrete to a new or existing structure. It is addition might affect the structural capacity and integrity. Therefore, concrete to concrete bond strength needs to be investigated to ensure continuous serviceability. This thesis presents an experimental study to characterize the mixes’ mechanical properties, the concrete-to-concrete bond strength, and the electrical properties of conductive concrete. Moreover, a self-consolidated concrete mix is used for all control samples and in concrete-to-concrete bond study. The mixes’ mechanical properties are evaluated using compression, modulus of elasticity, flexural third point loading, split tension, and direct shear tests. To evaluate the concrete-to-concrete bond strength, slant shear test with the addition of beforementioned tests are used except for split tension and direct shear tests. Furthermore, the conductive concrete electrical properties, namely its resistivity, are measured and analyzed as the material aged. The experimental results show that the compressive strength and the stiffness of the conductive concrete mix used in this study are approximately 13% and 35% lower than those of the self-consolidated concrete, respectively. The presence of steel fibers in the conductive concrete mix has improved the flexure strength and split tension 4 times, as well as direct shear 2.4 times of the self-consolidated concrete’s strength. Moreover, the best surface preparation technique in concrete-to-concrete bond strength is the shear key method. Additionally, the presence of conductive concrete layer at the tensile region yields the highest flexural strength, as observed in flexural tests. Furthermore, conductive fillers have improved the conductivity of the material. Moreover, steel fibers have improved the conductive concrete mix by further lowering the conductive concrete’s resistivity from 30 kΩ.mm to 0.5 kΩ.mm. Finally, a linear relationship is present between the compressive strength and the resistivity of the conductive concrete with respect to concrete aging.College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE