AUS Repository (American University of Sharjah)
Not a member yet
2669 research outputs found
Sort by
Design of a Power Amplification System for S-Band Satellite Applications
No full textA Master of Science thesis in Electrical Engineering by Ahmad Ibrahim R. Dalbah entitled, “Design of a Power Amplification System for S-Band Satellite Applications”, submitted in July 2021. Thesis advisor is Dr. Oualid Hammi. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).The satellite industry is in more demand than ever for more efficient satellites as they are getting smaller, and with it, the on-board power resources are also getting more limited. The high-power amplification section of the satellite consumes most of the power supplied to the system and is usually the least efficient subsystem of the satellite. Therefore, more efficient power amplification systems are vital for the upcoming small-satellites applications. To address this issue, a high-efficiency power amplification system with acceptable linearity performance is proposed. This system is designed to work in the S-band, specifically around the 3.5 GHz center frequency, with a targeted high efficiency in the range of 60% to 70% at a 6 dB output power backoff. The system is composed of two high efficiency amplifiers operating in the Doherty configuration which results in the high back-off efficiency. Simulations of the system were carried out using Advanced Design System (ADS) software with a large signal model of CGH40010F from Cree-Wolfspeed, which resulted in 62% to 75% of Power Added Efficiency (PAE) at peak output power of 43 dBm. The amplifier’s layout was then generated and tuned. The prototyped amplifier achieved an efficiency of 35% at 6 dB back-off and a maximum efficiency of 52% at peak power. It also meets out-of-band spectrum emission requirements for a satellite transmitter. Finally, the amplifier was linearized using digital predistortion (DPD) to ensure meeting the requirements of high order modulation schemes.College of EngineeringDepartment of Electrical EngineeringMaster of Science in Electrical Engineering (MSEE
Effects of Integrated Project Delivery and Information Communication Technology On Project Success
No full textA Master of Science thesis in Civil Engineering by Syed Shah Mohiuddin Quadri entitled, “Effects of Integrated Project Delivery and Information Communication Technology On Project Success”, submitted in December 2021. Thesis advisor is Dr. Irtishad Ahmad and thesis co-advisor is Dr. Sameh El Sayegh. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Project delivery systems are considered one of the most critical factors influencing project success. The downside of traditional methods is that they promote fragmentation, thus putting the main entities (stakeholders) in conflicts resulting in adversarial relationships rather than creating an integrated and collaborative environment. Integrated Project Delivery (IPD) is a promising and relatively new approach to project delivery in which collaboration and shared risks are the main features. Smart applications based on digital technologies play a very significant role in realizing the maximum benefits of IPD. In this research study, the incorporation of IPD Characteristics and Information Communication Technology (ICT) in the United Arab Emirates (UAE) construction industry is assessed through a questionnaire survey. The results show that the collaborative and behavioral IPD characteristics are implemented more than the contractual IPD characteristics. Further, the findings suggest that the collaborative and behavioral IPD characteristics contribute to a more significant extent than the contractual IPD characteristics. Subsequently, in this study, the effects of ICT tools on IPD characteristics (ICT pushes IPD) and the effects of IPD implementation on ICT effectiveness (IPD pulls ICT) are explored. The deployment of ICT tools to a greater extent has resulted in enhanced IPD implementation and vice versa. Increased ICT usage has also contributed to improvement in project success, indicated by selected success parameters. A similar pattern is observed for IPD characteristics, where an increase in the implementation of IPD characteristics has contributed towards an improvement in project success. Lastly, a decision model is developed to aid investment decisions involving ICT tools. The proposed research is focused on the UAE construction industry and utilizes the data and information available in this region to develop the decision model framework. The significant contribution of this research is filling the knowledge gap by investigating the effects of ICT tools and IPD characteristics on project success.College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE
Role of Active Morphing in the Aerodynamic Performance of Flapping Wings in Formation Flight
No full textMigratory birds have the ability to save energy during flight by arranging themselves in a V-formation. This arrangement enables an increase in the overall efficiency of the group because the wake vortices shed by each of the birds provide additional lift and thrust to every member. Therefore, the aerodynamic advantages of such a flight arrangement can be exploited in the design process of micro air vehicles. One significant difference when comparing the anatomy of birds to the design of most micro air vehicles is that bird wings are not completely rigid. Birds have the ability to actively morph their wings during the flapping cycle. Given these aspects of avian flight, the objective of this work is to incorporate active bending and torsion into multiple pairs of flapping wings arranged in a V-formation and to investigate their aerodynamic behavior using the unsteady vortex lattice method. To do so, the first two bending and torsional mode shapes of a cantilever beam are considered and the aerodynamic characteristics of morphed wings for a range of V-formation angles, while changing the group size in order to determine the optimal configuration that results in maximum propulsive efficiency, are examined. The aerodynamic simulator incorporating the prescribed morphing is qualitatively verified using experimental data taken from trained kestrel flights. The simulation results demonstrate that coupled bending and twisting of the first mode shape yields the highest propulsive efficiency over a range of formation angles. Furthermore, the optimal configuration in terms of propulsive efficiency is found to be a five-body V-formation incorporating coupled bending and twisting of the first mode at a formation angle of 140 degrees. These results indicate the potential improvement in the aerodynamic performance of the formation flight when introducing active morphing and bioinspiration.Brazilian agency CAPE
One Dimensional Seismic Site Response Analysis of United Arab Emirates
No full textA Master of Science thesis in Civil Engineering by Ahmed Mohamed Zaroug Eltayeb entitled, “One Dimensional Seismic Site Response Analysis of United Arab Emirates”, submitted in August 2021. Thesis advisor is Dr. Magdi El-Emam and thesis co-advisor is Dr. Zahid Khan. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Seismic design of structures located in seismically active areas, like UAE, is primarily based on Seismic Site Response Analysis (SRA) of that area. SRA is the process of estimating the response of soil layers under earthquake excitation (i.e., bedrock motion) and the characterization of earthquake ground motion at the ground surface. This research aims to investigate the significance of shear wave velocity correlation and degradation models on the site response analysis. Three different shear wave velocity correlation equations and two different degradation models have been used in the analysis which reflects the adaptation of laboratory generated, field generated, and literature developed correlations. Moreover, the two different degradation setups replicate the computer programs built-in models and the laboratory generated models, respectively. The lab generated velocity correlation and degradation models were developed using dynamic triaxial machine, binder element test, However, the fields models were developed based on field geophysical instrumentations. A number of 38 boreholes were collected and classified into three categories based on their calculated V30; lowest V30 [V30 ≅ 250 (/)], mean V30 [V30 ≅ 300 (/)], and highest V30 [V30 ≅ 350 (/)]. For each site, one dimensional site response analysis was performed using SHAKE2000. Results have shown that using site-specific shear wave velocity correlation can result in a totally different shear velocity distribution which can either result in different amplification factors or even change the site class of the soil in some cases. Moreover, the outcomes have depicted that the use of laboratory generated degradation models have led to an increase in the amplification factors values with respect to the outcomes obtained from using built-in degradation models. The amount of increase has ranged between 5% to 40%. These results justify the reason to generate site-specific shear wave correlations and degradation models, for seismic site response analysis.College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE
Hybrid Energy Management System For Electric Vehicles
No full textA Master of Science thesis in Electrical Engineering by Hazem Magdi Sharf entitled, “Hybrid Energy Management System For Electric Vehicles”, submitted in December 2021. Thesis advisor is Dr. Mohamed Hassan and thesis co-advisor is Dr. Ahmed Osman. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Boosting the performance of the energy storage system (ESS) of electric vehicles (EV) is of great significance to achieve their pervasion and encourage their mass adoption, which will, in turn, curtail the emission of greenhouse gases and promote a cleaner environment. The objective of this work is to develop and evaluate the capabilities of an EV hybrid energy storage system (HESS) that consists of a main source, namely the Lithium-ion (Li-ion) battery, and an auxiliary source, namely the supercapacitor (SC), to provide more efficient EV energy management. The integration of supercapacitors in EV energy storage systems (ESS) is expected to greatly enhance their performance by addressing high current requirements and extending the EV battery lifetime. Accordingly, this thesis proposes a strategy for managing the energy flow between the integrated battery-supercapacitor HESS and the EV motor to efficiently meet the energy requirements of the EV driving experience. Several simulations are implemented using MATLAB/Simulink to track the current output of each energy source, i.e. the Li-ion battery and the supercapacitor, and their corresponding state-of-charge (SoC). The performance and aging of the HESS operating with the proposed energy management strategy are then evaluated and compared to the performance of traditional ESS without supercapacitors by calculating different stress parameters and aging factors. Additionally, a scaled-down experimental model is developed and tested to validate the simulation results. Performance evaluation of the proposed HESS based on results of the conducted simulations and experiments reveal that the life expectancy of the battery banks is improved by an average of four times, which proves the employment of the SC bank to be cost-effective. Additionally, the remaining energy stored in the EV battery at the end of the driving cycle is higher when the SC bank is used, resulting in increased driving range.College of EngineeringDepartment of Electrical EngineeringMaster of Science in Electrical Engineering (MSEE
Task-Based Design Approach: Development of a Planar Cable-Driven Parallel Robot for Upper Limb Rehabilitation
No full textThis paper deals with the optimal design of a planar cable-driven parallel robot (CDPR), with three degrees of freedom, intended for assisting the patient’s affected upper limb along a prescribed movement. A Qualisys motion capture system was used to record the prescribed task performed by a healthy subject. For each pose taken by the center of mass of the end-effector, the cable tensions, the elastic stiffness and the dexterity were optimized while satisfying a set of constraints. First, a multiobjective formulation of the optimization problem was adopted. Since selecting a single solution among the multiple ones given by the Pareto front presents an issue, a mono-objective formulation was chosen, where the objective function was defined as a weighted sum of the chosen criteria. The appropriate values of the weighted coefficients were studied with the aim of identifying their influence on the optimization process and, thus, a judicious choice was made. A prototype of the optimal design of the CDPR was developed and validated experimentally on the prescribed workspace using the position control approach for the motors. The tests showed promising reliability of the proposed design for the task.PHC Utique program of the French Ministry of Foreign Affairs and Ministry of higher education, research and innovationTunisian Ministry of higher education and scientific research in the CMC
Identification of Novel MicroRNAs Targeting SARS-CoV-2 through the Regulation of TMPRSS2/PI3K/AKT/PTEN Alignment in Lung Cancer: An in Silico Analysis
No full textIn this study, we investigated the interactions between SARS-CoV-2 and miRNAs associated with lung cancer using bioinformatic approaches. A special focus was placed on TMPRSS2 and lung cancer progression pathways involving AKT/RAS/PI3K/PTEN genes
A Framework For Quality Management In Healthcare: From Hospital And Patient’s Perspective
No full textA Master of Science thesis in Engineering Systems Management by Waffa Maryam entitled, “A Framework For Quality Management In Healthcare: From Hospital And Patient’s Perspective”, submitted in May 2021. Thesis advisor is Dr. Hussam Alshraideh. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Healthcare quality is a complex term to dissect. As several perspectives integrate to assess it, no concrete definition exists, and continuous improvement is very important to cope with the modern-day lifestyle. While many definitions, practices, sophisticated tools have been introduced to understand, measure and assess healthcare quality, the healthcare industry is still struggling to provide state-of-the-art facilities and high-quality services. One of the major findings from the literature is that healthcare quality initiatives are lacking in integrating the perspectives of the main stakeholders that contribute to reciprocation of quality of healthcare. Three main stakeholders involved in determining quality are healthcare management, medical staff and patients. In most of the initiatives, healthcare management perspective and medical staff perspective have been given more importance, but patient perception of quality is ignored. This study intends to understand the important factors of healthcare quality from patient, medical and non- medical perspectives, identify the gaps between the quality perspectives through Confirmatory Factor Analysis and suggest dimensions that can lead to improved healthcare service quality. A structured questionnaire was used to assess the importance and significance of service creation and service delivery components in determining healthcare quality through the eye of the three healthcare stakeholders. The results indicate that administrative services, resource management, job satisfaction and healthcare waste are the main components of service creation process while on the other hand; equipment availability, database, trustworthiness, and patient outcomes are the main components of service delivery in the hospitals of UAE. However, these factors should be the main point of focus in both service creation process and at the point of service delivery to improve healthcare service provided through UAE hospitals.College of EngineeringDepartment of Industrial EngineeringMaster of Science in Engineering Systems Management (MSESM
Fluorescent Immunoassays for Detection and Quantification of Cardiac Troponin I: A Short Review
No full textCardiovascular diseases are considered one of the major causes of human death globally. Myocardial infarction (MI), characterized by a diminished flow of blood to the heart, presents the highest rate of morbidity and mortality among all other cardiovascular diseases. These fatal effects have triggered the need for early diagnosis of appropriate biomarkers so that countermeasures can be taken. Cardiac troponin, the central key element of muscle regulation and contraction, is the most specific biomarker for cardiac injury and is considered the “gold standard”. Due to its high specificity, the measurement of cardiac troponin levels has become the predominant indicator of MI. Various forms of diagnostic methods have been developed so far, including chemiluminescence, fluorescence immunoassay, enzyme-linked immunosorbent assay, surface plasmon resonance, electrical detection, and colorimetric protein assays. However, fluorescence-based immunoassays are considered fast, accurate and most sensitive of all in the determination of cardiac troponins post-MI. This review represents the strategies, methods and levels of detection involved in the reported fluorescence-based immunoassays for the detection of cardiac troponin I.American University of Sharja
pH and ultrasound dual-responsive drug delivery system based on PEG–folate-functionalized Iron-based metal–organic framework for targeted doxorubicin delivery
No full textIn recent years, the use of metal–organic frameworks (MOFs) as drug nanocarriers has gained attention because of their extraordinary physical and chemical properties. In this work, dual-responsive iron-based MOFs were synthesized via the microwave-assisted method using FeCl₃.6 (H₂O) as the metal cluster and 2-aminoterephthalic acid (NH₂-BDC) as the organic linker (namely NH₂-Fe-BDC) and loaded with the anti-cancer drug doxorubicin (DOX). The DOX-loaded MOFs were further functionalized with polyethylene glycol-folate (PEG–FA), yielding PEG–FA-NH₂-Fe-BDC. The folate moiety is used to specifically target several cancers overexpressing the folate receptor (FR). These nanoparticles were characterized using Fourier-Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA), and Dynamic Light Scattering (DLS). The FTIR confirmed the PEG–FA conjugation to the MOFs, while the XRD patterns confirmed the crystallinity of the nanoparticles. TGA results demonstrated the thermal stability of the MOFs. Moreover, the DLS analysis showed that regular MOFs had a particle diameter of 577 nm, while the PEG–FA-functionalized MOF had a particle diameter of 461 nm, which demonstrates the improved colloidal stability of the functionalized MOF. The DOX encapsulation efficiency was determined to be approximately 97%, while the encapsulation capacity was around 14.5 wt%. Furthermore, the in-vitro release profiles were studied under different pH values (5.3 and 7.4) with and without low-frequency ultrasound (LFUS, at 40 kHz). The results confirmed the sonosensitivity of the nanovehicles, with US-triggered release efficiency reaching up to 90% after 280 min (at a pH of 5.3). The MTT study revealed that these nanocarriers are non-toxic at lower concentrations. Their toxicity increases at higher concentrations. Furthermore, the cellular uptake was investigated via flow cytometry, and the results showed that the conjugation of the PEG-FA moiety to the MOF’s surface significantly enhanced uptake by cancer cells. Accordingly, this study showed the pH/US dual-responsive capability of NH₂-Fe-BDC and PEG–FA-NH₂-Fe-BDC.American University of Sharja