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The role of vigilance on a discrete-time predator-prey model
No full textThe change of behaviors of prey in the form of vigilance significantly affects the dynamics of a predator-prey system. In this paper, we consider a discrete-time predator-prey model, where the vigilance of prey acts as a trade-off between the safety and growth rate of the prey. Mathematical properties such as stability, permanence, both flip and Neimark-Sacker bifurcations of the model are investigated. Numerical simulations are carried out to illustrate the analytical findings and to explore the impact of prey vigilance on the dynamics of the system.American University of Sharja
Thermosensitive Polymers and Thermo-Responsive Liposomal Drug Delivery Systems
No full textTemperature excursions within a biological milieu can be effectively used to induce drug release from thermosensitive drug-encapsulating nanoparticles. Oncological hyperthermia is of particular interest, as it is proven to synergistically act to arrest tumor growth when combined with optimally-designed smart drug delivery systems (DDSs). Thermoresponsive DDSs aid in making the drugs more bioavailable, enhance the therapeutic index and pharmacokinetic trends, and provide the spatial placement and temporal delivery of the drug into localized anatomical sites. This paper reviews the fundamentals of thermosensitive polymers, with a particular focus on thermoresponsive liposomal-based drug delivery systems.Dana Gas Endowed Chair for Chemical EngineeringAmerican University of SharjahSheikh Hamdan Award for Medical SciencesFriends of Cancer Patien
Digital Predistortion Using Relaxed Sampling Rates
No full textA Master of Science thesis in Electrical Engineering by Serien Ahmed entitled, “Digital Predistortion Using Relaxed Sampling Rates”, submitted in November 2022. Thesis advisor is Dr. Oualid Hammi. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Wireless communication's high data rates demands are continuously increasing, thus leading to higher requirements on digital circuits. This leads to complications in the power amplifier's (PA) efficiency and linearity specifications. Accordingly, digital predistortion (DPD) is used to compensate for the nonlinearity of the PA when operating at high-efficiency levels. In DPDs, the bandwidth limitations in the transmitter forward and feedback chains put challenges on the hardware circuits, such as digital to analog converters (DACs) and analog to digital converters (ADCs). This thesis explores the co-existence of relaxed sampling rates in the signal transmit and the signal feedback paths. First, the sampling rate reduction in the feedback path was investigated. The DPD function for this case was extracted using advanced signal processing techniques for constructing the full-rate output from under-sampled measurements. This method was validated in the presence of 20MHz, and 40MHz 5G test signals with several sampling speeds, and the DPD functions were extracted using a twin nonlinear two-box model (RTNTB). Even for an 80% reduction, sufficient linearization capacities were achieved. While a novel predistorter suitable for hybrid implementation was proposed for the transmit path, the distortion function is split into a memory polynomial applied in the baseband domain and an AM/AM only look-up table (LUT) suitable for the RF domain. The hybrid model was compared to benchmark models using 5G test signals with bandwidths of 20MHz and 40MHz and found to provide superior ACLR levels of above 50dBc and a low number of coefficients of 22% less than the benchmarks. The hybrid implementation of the proposed model significantly reduces the speed requirements in the DAC of the transmit path by 70% when compared to conventional DPD systems. Finally, to study the concurrent usage of relaxed sampling rates in both paths, the under-sampled reconstructed output signals were used to build the hybrid predistorter. It was found that a sampling rate reduction of 80% in the feedback path would still provide a 70% reduction of DAC speed in the transmit path while leading to satisfactory linearization performance.College of EngineeringDepartment of Electrical EngineeringMaster of Science in Electrical Engineering (MSEE
Environment, Education, and Personality Innovation Based Index
No full textA Master of Science thesis in Engineering Systems Management by Mahmoud Ghandi Mahmoud Al Qawasmi entitled, “Environment, Education, and Personality Innovation Based Index”, submitted in April 2022. Thesis advisor is Dr. Hussam Alshraideh. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Innovation and Entrepreneurship (I&E) are evolving as highly important concepts around the world, as they heavily contribute to the economic development of many countries. Identifying, educating, and supporting innovators and entrepreneurs are urgent and crucial as there are no innovators and entrepreneurs’ identification frameworks exist yet considering all aspects of I&E. As researchers highlight the importance of I&E in societies, they tried to identify the related factors affecting the development of innovators and entrepreneurs by developing and using different models, such as the General Enterprise Tendency Index, the Complex Process Model of Entrepreneurship, and the Global Entrepreneurship Index. Factors related to I&E as found in the literature are classified as environmental factors, personal factors, and academic performance-related factors. However, the topic of how to identify innovators and entrepreneurs using all three factors combined, and how these factors interact is still ambiguous and needs to be studied. In this thesis, a framework is developed to model and assess the effect of I&E-related factors and their interaction on a newly developed I&E index. We developed a literature review-based questionnaire that addresses all three factors and their effects. Collected responses were analyzed through a Structural Equation Modelling (SEM) approach. The model consisted of three constructs representing the three factors found in the literature and an output variable representing the proposed I&E index. To evaluate the developed model, the Tucker-Lewis Index (TLI), the Comparative Fit Index (CFI), the Root Mean Square Error (RSME) of Approximation, and the P-value were utilized. Model metrics showed an excellent model fit with CFI of 0.911, TLI of 0.905, RMSEA of 0.036, and a p-value of 0.000. Although model results indicate significant effects of the three factors on the developed I&E index, the personal traits factor had the highest effect encouraging more research on personality development for better innovation and entrepreneurship achievements among individuals.College of EngineeringDepartment of Industrial EngineeringMaster of Science in Engineering Systems Management (MSESM
Combined and Single Doxorubicin/Naproxen Drug Loading and Dual-Responsive pH/Ultrasound Release from Flexible Metal-Organic Framework Nanocarriers
No full textIn this study, the flexible aluminum-based MIL-53(Al) metal-organic framework was loaded with doxorubicin (DOX) and naproxen (NAP) and was examined as a promising pH/ultrasound dual-responsive drug delivery system. The two drugs were encapsulated in MIL-53(Al) individually to produce the DOX@MIL-53(Al) and NAP@MIL-53(Al) nanocarriers. They were also encapsulated as a dual-drug formulation to produce the DOX* +NAP*@MIL-53(Al) nanocarrier. The MOF nanoparticles were characterized using the Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Fourier Trans- form Infrared spectroscopy (FTIR), and Dynamic Light Scattering (DLS) techniques. In the case of the DOX@MIL, the nanocarriers’ drug Encapsulation Efficiency (EE) and Encapsulation Capacity (EC) were 92% and 16 wt.%, respectively, whereas, in the case of NAP@MIL-53(Al), the average NAP EE and EC were around 97.7% and 8.5 wt.%, respectively. On the other hand, in the DOX* +NAP*@MIL-53(Al) nanoparticles, the average DOX* EE and EC were 38.9% and 6.22 wt.%, respectively, while for NAP*, the average EE and EC were 70.2% and 4.49 wt.%, respectively. In vitro release experiments demonstrated the good pH and Ultrasound (US) dual-responsiveness of these nanocarriers, with a maximum US-triggered DOX and NAP release, at a pH level of 7.4, of approximately 53% and 95%, respectively. In comparison, the measured release was around 90% and 36% at pH 5.3 for DOX and NAP, respectively. In the case of the dual-drug formulation, the nanocarrier displayed similar pH/US dual-responsive behavior. Finally, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) results confirmed the biocompatibility and low cytotoxicity of MIL-53(Al) at concentrations up to 1000 µg/ml.American University of Sharja
Block copolymer micelles as long-circulating drug delivery vehicles
No full textMedical applications of nanotechnology have attracted growing interest in recent years, particularly in the field of drug delivery, because of nanotechnology’s ability to overcome the limitations of existing treatment modalities, including nonselective systemic activity, poor drug solubility, hepatic bio-degradation, dose-limiting toxicity, and damage to healthy cells. Smart drug delivery systems (SDDSs) are nanoplatforms with unique characteristics and biofunctions that make them ideal for the remote delivery of drugs to targeted sites under controlled release conditions. A variety of SDDSs have been developed, including carbon nanotubes, quantum dots, metalorganic frameworks, micelles, and liposomes. Ideally, SDDSs should remain stable while circulating in the bloodstream of a patient, avoid unspecific interactions with blood components and the reticuloendothelial system (RES), and selectively extravasate at the diseased site. Among the myriad SDDSs, micelles are notable nanocarriers that have gained immense popularity as drug delivery vehicles. Micellar systems have demonstrated unique advantages, such as their adaptability to a wide range of applications, increased drug bioavailability, and tunability of payload release kinetics. Moreover, micelles have high drug-loading and encapsulation capacities and enhanced capabilities of intracellular accumulation that allow for localized delivery to specific anatomical sites
Design and Utilization of a Direct Methanol Fuel Cell
No full textThis study introduces a step-by-step, summarized overview of direct methanol fuel cell (DMFC) fundamentals, thermodynamic–electrochemical principles, and system evaluation factors. In addition, a parametric investigation of a JENNY 600S DMFC is conducted to simulate cell performance behavior under varying operating conditions. The system is mathematically modeled and solved in MATLAB and accounts for multi-irreversibilities such as the activation and ohmic and concentration overpotentials. The performance of the modeled system was validated against theoretical and experimental results from the literature. The results indicated that increasing the fuel cell’s operating temperature yields enhanced output cell voltages due to enhanced methanol oxidation reactions. Nevertheless, the maximum efficiency limits of the fuel cell tend to decrease with an increase in temperature. In addition, the model has also depicted that enhanced output cell voltages are associated with increased oxygen consumption, resulting in the lower exit flowrates of the reactants.American University of Sharja
Empirical Evaluation of Extended Finite State Machine Test Suites
No full textA Master of Science thesis in Computer Engineering by Faiz Mohammed Hasan entitled, “Empirical Evaluation of Extended Finite State Machine Test Suites”, submitted in May 2022. Thesis advisor is Dr. Khaled El-Fakih. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).We present novel empirical assessments of prominent finite state machine (FSM)-based test derivation methods against their coverage of code faults. In particular, we consider many realistic extended FSM examples and their related Java implementations and then derive for these examples complete test suites using the W method and its HSI and H derivatives in addition to singe transfer fault test suites. The W, HSI, and H test suites are derived considering the case when the implementation under test (IUT) has the same number of states as the specification FSM, and we also consider W++, HSI++, and H++ test suites derived when the IUT can have one state more than the specification machine. An assessment is then provided to determine for each pair of considered test suites if there is a difference between the pair in covering the implementations faults. If the difference is found significant, we determine which test suite outperforms the other. According to conducted experiments, the W method and its derivatives do not provide the same fault coverage of code faults; in contrast to their similar coverage of FSM-based faults. We further show that the results of this result are not due to size nor length of the test suites. In addition, as W tests outperformed both HSI and H tests, we further investigated whether these differences were due to certain types of faults or are spread over all classes of faults. Besides, another assessment is provided to determine whether certain test suites have better coverage of some classes/types of code faults than others. The empirical assessments use proper data transformation of mutation scores and p-value adjustments for controlling Type I error due to multiple tests. Results and outcomes of conducted experiments are summarized.College of EngineeringDepartment of Computer Science and EngineeringMaster of Science in Computer Engineering (MSCoE
Arabic-Chinese and English Relay Translation (1970-2020): A Historiographical Bibliometric Study
No full textA Master of Arts thesis in English/Arabic/English Translation and Interpreting (MATI) by Luxi Xiang entitled, “Arabic-Chinese and English Relay Translation (1970-2020): A Historiographical Bibliometric Study”, submitted in April 2022. Thesis advisor is Dr. Said Faiq. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).The dissemination of Arab heritage has a long history in China, but the first genuine Arabic-Chinese translation interchange did not occur until a century ago. The translation of the classic, Arabian Nights, helped the Chinese people understand Arab culture for the first time. On the other hand, the development of Chinese in Arab countries has a very recent history. Since the classic Chinese book, The Analects, was translated into Arabic by Ma Jian a century ago, the translation of Chinese literary works remains rare, with the majority of them being translated from English or other western languages via relay translation. In the twentieth century, the government of China vigorously promoted exchanges between Chinese and Arab cultures, which has further deepened the cultural encounters between the two nations. This thesis examines translation from Arabic into Chinese from 1970 to 2020, with a historiographical and bibliometric approach, including through English relay translation.College of Arts and SciencesDepartment of Arabic and Translation StudiesMaster of Arts in English/Arabic/English Translation and Interpreting (MATI
A Decision Support Model for Prequalifying IPD Project Participants in Construction Projects
No full textA Master of Science thesis in Construction Management by Ahmad El Masri entitled, “A Decision Support Model for Prequalifying IPD Project Participants in Construction Projects”, submitted in November 2022. Thesis advisor is Dr. Sameh El-Sayegh. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Integrated Project Delivery (IPD) is an innovative and collaborative delivery method in the construction industry. It has recently gained momentum after several projects in the US, and other regions, with partial utilization of IPD, showed great results. One of the key success factors is the proper selection of major project participants. The literature review revealed absence of decision support models that assist clients in selecting project participants based on their suitability for IPD. The lack of such models decreases the chances of a successful IPD implementation. This thesis aims to introduce a robust decision support model that helps prequalify project participants based on their suitability for IPD implementation. Twenty critical IPD project participant selection criteria were identified through extensive literature review. Indicators, for each of the criteria, were determined to facilitate the usage of the model. A questionnaire was then administered to 44 construction professionals with knowledge of IPD to evaluate the effectiveness of the identified criteria based upon an Analytic Hierarchy Process (AHP) methodology. The results show that the most effective criteria are “3D BIM Modelling,” with a global weight of 0.103, and “Project Management Information Systems and Cloud Computing Proficiency,” with a global weight of 0.099. Both belong to the “IT Infrastructure” criteria group, emphasising the group’s importance as the most effective group of criteria. “Experience with Multiparty Contract Agreements” and “Readiness to waive claims and share risks and rewards,” both founding principles of IPD, follow with global weights of 0.084 and 0.079 respectively. Profiling of the collected responses shows the influence of IPD-experienced professionals’ responses on the results, confirming the reliability of the results. A decision support model framework was developed to assist clients in selecting the most suitable firm for IPD implementation. The model provides decision-makers with an IPD suitability score that aids with the assessment of the readiness and responsiveness of firms for the implementation of IPD. Finally, a case study is used to demonstrate the use of the model. A sample Request for Qualifications (RFQ) is presented to guide the model usage.College of EngineeringMultidisciplinary ProgramsMaster of Science in Construction Management (MSCM