AUS Repository (American University of Sharjah)
Not a member yet
2669 research outputs found
Sort by
CFRP U-Wraps and Spike Anchors for Enhancing the Flexural Performance of CFRP-Plated RC Beams
No full textDeterioration of infrastructure is a major challenge in the civil engineering industry. One of the methods that has been deemed effective in upgrading reinforced concrete (RC) structures is using externally bonded fiber-reinforced polymer (FRP) composites. However, the efficacy of this retrofitting technique is limited by the premature debonding failure of the FRP at the concrete-FRP interface; thus, the full capacity of the FRP is rarely utilized. Anchorage systems were proposed as a feasible solution to suppress or delay debonding failure. This paper presents an experimental investigation on the use of end U-wraps and carbon FRP (CFRP) spike anchors to anchor CFRP plates bonded to flexure-deficient RC beams. The experimental program consisted of seven RC beams with the length of the CFRP plate, type of anchorage, and the number of anchors as experimental variables. Test results indicated a remarkable enhancement in the ultimate load-carrying capacity when longer CFRP plates were used to strengthen the beams. In addition, anchoring the plates enhanced the strength of the CFRP-plated beams by 16–35% compared to the unanchored specimen, depending on the anchorage type and scheme. Finally, fib Bulletin 90 (2019) provisions provided the most accurate predictions of the moment capacity of the strengthened specimens.American University of Sharja
Introductory Painting - ART 241
No full textSyllabus for the Department of Art and Design course "Introductory Painting - ART 241", by Instructor(s) Philip Sheil for the Summer 2023 semester.College of Architecture, Art and DesignDepartment of Art and Desig
Rating vs. Reviews: Does official rating capture what is important to customers?
No full textThis paper examines the relationship between hotels' official ratings and customer review scores. Hotel ratings aim to provide an objective assessment of the hotel's quality and experience to potential customers. However, customer reviews frequently differ from official ratings. We use data on hotels in Dubai to explore their relationship and analyze their similarities and differences. Asymmetric information hampers demand in the hotel industry if ratings do not match the customers' views of quality. Furthermore, substantial discrepancies between the two measures provide competing interests for hotel managers to satisfy rating agencies' criteria or customers' preferences, reducing the hotels' efficiency and effectiveness in offering customers the best experience and value. Our findings show that, as expected, Star Rating primarily reflects hotel-related features. In contrast, customer review scores tend to appreciate features nearby in addition to hotel amenities. Also, some hotel amenities value differently in the customer review scores and Star Rating.Open Access Program at the American University of Sharja
Liposomal Encapsulation of Chemotherapeutics Agents Combined with the Use of Ultrasound in Cancer Treatment
No full textUltrasound (US) has numerous uses in the medical field, including imaging, tumor ablation, and lithotripsy; another interesting application of US in cancer therapy is as an external trigger in targeted drug delivery. Cancer-targeted drug delivery involves delivering chemotherapeutic drugs to tumor sites with a high degree of precision, which would minimize the adverse side effects experienced by patients. Several nanocarriers have been studied as possible nanocarriers; however, liposomes stood out from the rest because of their non-immunogenicity, amphiphilic nature, ease of functionalization, and stimuli-responsiveness. This review addresses the role of US in the synthesis of liposomes, its ability to induce localized and controlled drug release from liposomes, as well as the integration of US-induced release and US-imaging using liposomes as contrast agents utilizing thermal and/or mechanical effects.American University of SharjahAl-Jalila FoundationAl Qasimi FoundationPatient's Friends Committee of 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
Collision-Free Autonomous Navigation Solution for Mobile Wheeled
No full textA Master of Science thesis in Mechanical Engineering by Ahmed Moataz Mahmoud Elsergany entitled, “Collision-Free Autonomous Navigation Solution for Mobile Wheeled”, submitted in April 2023. Thesis advisor is Dr. Mamoun Abdel-Hafez and thesis co-advisor is Dr. Mohammad Jaradat. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Unmanned Ground Vehicles (UGVs) have become an imperative tool that is employed in a wide range of industrial sectors including oil and gas, agriculture, and defence. Their autonomy makes them an excellent choice for remote operations, particularly in complex outdoor environments. Therefore, the development of outdoor navigation solutions for UGVs has received the attention of many researchers in the field. This thesis is concerned with improving the outdoor localization of autonomous vehicles that use low-cost Global Positioning System (GPS) and Inertial Navigation System (INS) sensors in their operations. We propose a novel Kalman Filter (KF) based sensor fusion algorithm for low-cost and loosely coupled GPS/INS integration that tackles the linearization issues of a conventional Extended Kalman Filter (EKF) as well as addresses the errors associated with the Unscented Transformation (UT) of quaternion states in the traditional Unscented Kalman Filter (UKF) found in literature. Our algorithm termed the Augmented Quaternion Unscented Kalman Filter (AQUKF) offers an improved sensor fusion algorithm that accurately estimates both quaternion and non-quaternion states. Additionally, we consider the use of a multi-input Fuzzy Inference System (FIS) to recursively update the measurement noise covariance of our stochastic filter to match the noise statistics of the actual system. The resulting Fuzzy Adaptive Augmented Quaternion Unscented Kalman Filter (FA-AQUKF) reduces estimation uncertainties with the additional adaptive component, thus improving the accuracy of our localization solution. Initially, the performance of our proposed algorithms is evaluated using experimentally generated vehicle trajectories and validated against commercial solutions. Upon achieving satisfactory results, the algorithms are then implemented in real-time for the autonomous navigation of a Robot Operating System (ROS) operated UGV in the presence of static and dynamic obstacles. Results of all conducted experiments prove that our proposed algorithms deliver a significant improvement in vehicle state estimation and outdoor localization, besides satisfying the practical level of safety and accuracy desired for practical autonomous navigation applications.College of EngineeringDepartment of Mechanical EngineeringMaster of Science in Mechanical Engineering (MSME
Design, Implementation, and Performance Analysis of Actively
No full textA Master of Science thesis in Mechanical Engineering by Osama Al Hussaini entitled, “Design, Implementation, and Performance Analysis of Actively”, submitted in May 2023. Thesis advisor is Dr. Lotfi Romdhane and thesis co-advisor is Dr. Mehdi Ghommem. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).The new technology of morphing wings has potential to impact the aeronautic industry as it greatly reduces the associated operational costs. This is achieved by drastically lowering the fuel consumption of aircrafts and enhancing their flight performance. Morphing wings have the capability to change their shape dynamically to achieve numerous aerodynamic characteristics that can fit different flight missions and operating environments. In this Thesis report, we investigate the potential enhancement in the aerodynamic performance of morphing wings made of NACA0012 airfoil. An aerodynamic analysis was first carried out to identify optimum morphing configurations. The obtained wing profiles showed capability to significantly increase the lift coefficient and reduce the drag coefficient, resulting in a high lift-over-drag ratio. The numerical analysis was conducted by interfacing the aerodynamic simulation tool XFOIL with MATLAB to obtain a user-friendly tool that eased the aerodynamic analysis and the optimization study. Based on the morphing shapes obtained from the optimization analysis, a morphing wing prototype was developed and tested. The prototype uses the Fish Bone Active Camber (FishBAC) mechanism to induce morphing in the trailing edge portion of the wing structure. Moreover, the FishBAC used in this Thesis was enhanced by adding an additional degree of freedom, which is an unprecedented contribution to this particular mechanism. The second degree of freedom significantly improved the morphing efficiency. Wind tunnel tests were conducted on the developed wing prototype to inspect the lift generation under various airspeeds and morphing configurations. Experimental measurements showed evidence of 60% increase in the lift thanks to the incorporation of morphing obtained from the optimization analysis. The experimental results showed also qualitative agreement with their numerical counterparts.College of EngineeringDepartment of Mechanical EngineeringMaster of Science in Mechanical Engineering (MSME
Shear performance of FRP Reinforced Deep Beams Made of Ultra High Performance Concrete (UHPC)
No full textA Master of Science thesis in Civil Engineering by Omar Salman entitled, “Shear performance of FRP Reinforced Deep Beams Made of Ultra High Performance Concrete (UHPC)”, submitted in December 2023. Thesis advisor is Dr. Farid Abed. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).This thesis studied the shear performance of ultra high performance concrete (UHPC) deep beams reinforced longitudinally with glass fiber reinforced polymer (GFRP) bars without web reinforcements. Eight beams were longitudinally reinforced with GFRP bars, while the remaining were reinforced with steel bars for comparison. All beams had similar lengths and widths of 2000 mm and 150 mm, respectively, while the depths varied. The parameters investigated were the effective depth (d), shear span-to-depth ratio (a/d), number of longitudinal bars, and longitudinal reinforcement ratio (ρ). The shear performance of the beams was reported in terms of load deflection response, strains in the concrete and reinforcement, failure modes, and ultimate capacity. All the GFRP reinforced beams had higher shear capacities and lower post cracking stiffness than their steel counterparts. The test results show that decreasing the a/d ratio for the GFRP reinforced beams from 1.8 to 1.5 and from 1.8 to 1.1 increased the peak load by 33% and 95%, respectively. Moreover, the GFRP reinforced beam with 1.1 a/d ratio had 13% higher peak load than its steal counterpart. Also, increasing the depth of the GFRP reinforced beams, from 260 to 310 mm and from 260 to 360 mm, increased the peak load by 23% and 34%, respectively. However, the steel reinforced beams only saw an increase of 26% when the depth was increased from 260 to 360 mm. The increase in depth in the GFRP reinforced beam may have allowed the GFRP bars to deform more, which increased the tensile strength of the tie, thus providing a higher increase in the peak load. The experimental results for the shear capacity were compared against the predictions obtained using the strut and tie method as per the ACI-318-19 and CSA-S806-12 codes. The failure load predictions by the ACI and CSA code showed the same trends as those shown in the experimental results. Moreover, both codes were conservative in predicting the shear capacities.College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE
INScription: Department of International Studies (INS) Issue #14 (April 27, 2023, Issue 4)
No full textCollege of Arts and SciencesDepartment of International Studie
Fire Performance of FRCM Strengthened Columns: Experimental Investigation
No full textA Master of Science thesis in Civil Engineering by Salem Mazen Khalaf entitled, “Fire Performance of FRCM Strengthened Columns: Experimental Investigation”, submitted in November 2023. Thesis advisor is Dr. Farid Abed and thesis co-advisor Dr. Ahmed El Refai. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).The utilization of Externally Bonded (EB) fiber systems for the rehabilitation and retrofitting of existing and deteriorated RC structures has grown in recent decades, given their demonstrated promise and convenience. Fiber Reinforced Polymers (FRP) system is the most common type of EB strengthening systems. However, one of the main concerns about FRP strengthening systems are their low resistance to elevated temperatures or fire exposure. This poor fire performance of FRP systems motivated researchers to use different fireproofing systems or use a more durable type of EB fiber systems. Fabric Reinforced Cementitious Matrix (FRCM) strengthening system has been introduced as an alternative to FRP systems, especially when there is a high risk of fire exposure. This thesis investigates the fire performance of twenty short circular RC columns strengthened with poly-paraphenylene-ben-zobisoxazole (PBO) FRCM and Carbon FRP (CFRP) systems. The columns were categorized into two phases, each featuring different post-curing storage times. The study examined various parameters, including the choice of strengthening system (PBO-FRCM or CFRP), the number of strengthening layers (ranging from 0 to 4 layers), the type of fireproofing applied (none, Sikacrete 213F, or intumescent paint), and exposure to fire. Following ASTM E119 standards, columns from both phases were subjected to fire exposure in a full-scale furnace, while phase 2 columns underwent testing under concentric loading until failure after fire exposure. Results showed that the use of cement-based insulation has significantly reduced the temperature readings at all locations within the section by 60%. The cement-based insulated PBO-FRCM strengthened column demonstrated the highest resistance to fire exposure, as the temperature readings were significantly less than the other columns, and it retained about 92.1% load capacity of the unexposed counterpart. Additionally, the cement-based insulated PBO-FRCM strengthened column underwent minimal displacement when subjected to a sustained load during the fire test. The column’s axial capacity was predicted using different ACI codes and developed models. The predicted capacity of the unexposed columns using ACI codes were within 7% of the actual capacity, while the model used to estimate the post-fire axial capacity was within 14%.College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE
Evaluating the factors affecting microplastic removal from synthetic leachate via electrocoagulation
No full textA Master of Science thesis in Civil Engineering by Zahraa Al-Dawood entitled, “Evaluating the factors affecting microplastic removal from synthetic leachate via electrocoagulation”, submitted in November 2023. Thesis advisor is Dr. Md. Maruf Mortula and thesis co-advisor is Dr. Kazi Fattah. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).The ubiquitous presence of microplastics in the environment has raised concerns over their impact on human, environmental and ecological health. Landfill leachate, which is the highly toxic wastewater produced in landfills, is a primary source of microplastics into the soil and groundwater. Though microplastics have been detected in landfill leachate, studies on their presence and removal remain limited. Electrocoagulation has recently emerged as a viable and efficient wastewater treatment process. Although microplastic removal using electrocoagulation has been studied, the impact of the inter-electrode distance, the interaction between the variables, and the sample preparation technique need to be investigated. This study evaluates the effectiveness of electrocoagulation in the removal of microplastics from synthetic leachate sample to address these important gaps. Polyvinyl chloride samples were weathered using UV light before microplastics were leached from the samples to synthesize a wastewater sample containing weathered secondary microplastics. The electrocoagulation experiments were conducted across two phases whilst varying the inter-electrode distance (1-3 cm), initial pH (5-9), electrode material (aluminum and iron), current density (2-10 mA/cm2) and electrolysis time (15-45 minutes). The results show that electrocoagulation is effective in removing microplastics, with removal efficiencies exceeding 85% reported for all the experiments conducted. The analysis of the results show that the effects of the pH and inter-electrode distance were not significant for the removal of microplastics using aluminum electrodes but that the pH2 interaction was significant for the iron electrodes at a confidence level of 90%. The paired t-test results show that both electrode types were effective in removing microplastics and were statistically indifferent. In the second phase of the experiment, the current density and electrolysis time were found to be statistically significant with p-values of 0.0001 and 0.000, respectively. The optimal variables were consequently determined as: aluminum electrodes, inter-electrode distance of 2 cm, current density of 6 mA/cm2, and electrolysis time of 45 minutes, yielding a removal efficiency of 98%. The important findings of this study can be used in future studies to assess the removal of microplastics using electrocoagulation from real wastewater samples.College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE