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Carbon Dots-Based Polymer Composites for Conductive Electrodes
No full textA Master of Science thesis in Biomedical Engineering by Amaal Abdulraqeb Ali entitled, “Carbon Dots-Based Polymer Composites for Conductive Electrodes”, submitted in April 2023. Thesis advisor is Dr. Mohammad H. Al-Sayah and thesis co-advisors are Dr. Amani Al-Othman and Dr. Hasan Al-Nashash. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Flexible electrodes have become a topic of interest for implantable applications such as stimulation of muscles atrophying due to nerve damage. Implantable electrodes used for signal recording and/or signal stimulation are composed of metals and metal alloys to benefit from metal’s high conductivity, corrosion resistance, and stability. However, due to their inherent rigidity, metal electrodes are limited by their mechanical mismatch with the soft biological tissues. Therefore, flexible alternatives are needed to replace metal electrodes. Several conductive and flexible polymers have been explored to replace metal composites. However, polymer-based composites still possess limitations including high rigidity or toxicity issues. This study presents flexible electrodes based on the highly elastic polymer polydimethylsiloxane (PDMS) and the conductive dopant boronic acid-modified carbon dots (BA-CDs). The potential of the composites as flexible electrodes was evaluated based on their: 1) electrochemical properties (conductivity, bulk resistance, impedance at 1 kHz, charge storage capacity (CSC), and electrochemical stability), 2) elasticity (Young’s modulus), 3) biocompatibility, 4) stability in body-like environment and 5) ability to record electrophysiological signals. The developed electrodes composed of 10% BA-CDs and 74% PDMS with 16% glycerol (dispersant) showed a promising conductivity of 9.62±3 .45×10⁻³ S/cm, bulk resistance 0.058±0.0135 kΩ, impedance at 1 kHz of 0.964± 0.361 MΩ, and a CSC of 21.4±5.9 C/cm². Mechanically, the electrodes had a flexibility of 0.0505 ± 0.0218 MPa that is compatible with biological tissues. Post-incubation in phosphate buffer saline (body-like environment), the electrodes performance improved electrochemically but deteriorated mechanically (0.1562 ± 0.0274 MPa) although to a degree still compatible with biological tissues. As surface electrodes, the electrodes recorded heart activity (electrocardiography) and muscle activity (electromyography) with a signal quality comparable to that of the commercial Ag/AgCl electrodes. In terms of biocompatibility, the electrodes showed some toxicity toward cells in vitro. However, future dose-response experiments using the conventional fibroblast L929 cells need to yet be conducted to obtain a more accurate understanding of the toxicity of the material.College of EngineeringMultidisciplinary ProgramsMaster of Science in Biomedical Engineering (MSBME
Six bold steps towards net-zero industry
No full textThe rapid and deep decarbonization of global industry is key to reaching climate policy targets, yet it remains an incredibly difficult challenge. We propose six bold steps for accelerating progress on achieving net-zero industrial carbon emissions by mid-century with a focus on lessons learned and emerging analysis from both the Global North and Global South, the latter of which we consider as low or middle income countries primarily located in Africa, Asia and Latin America. These steps are (1) quintupling financing, (2) expediting technology transfer, (3) investing in human resources, (4) setting binding targets, (5) steering social acceptance and (6) enacting a new global treaty and shaping climate clubs. Perhaps surprisingly, there are more than thirty effective historical and contemporary initiatives to learn from, showcasing a rich tapestry of previous efforts and templates to build on and to inform net-zero decarbonization efforts.UK Industrial Decarbonisation Research and Innovation Centre (IDRIC)European Research Council (ERC
Mxene-Based Implantable and Flexible Electrodes for Neuromuscular Monitoring
No full textA Master of Science thesis in Biomedical Engineering by Kashif Rast Baz Khan entitled, “Mxene-Based Implantable and Flexible Electrodes for Neuromuscular Monitoring”, submitted in June 2023. Thesis advisors are Dr. Amani Al Othman, Dr. Hasan Al Nashash, and Dr. Muhammad Al Sayah. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Biocompatible and long lasting bioelectrodes have advanced neural sensing and muscle stimulation research in recent years. Previously, bioelectrodes constructed from metals suffered from mechanical and immunological limitations that resulted in extremely high electrochemical resistances that would interfere with the neural-electrode bridge. They also had the problem of causing an immunologic response in the body due to mechanical mismatch and they lacked the flexibility. This shifted research to the development of soft, flexible electrodes that had low electrochemical resistances. In this thesis proposal we investigated the possibility of developing novel, flexible, implantable bioelectrodes based on Mxenes / Polydimethylsiloxane (PDMS) / Glycerol composite. MXenes possess the advantage of having metallic ultra-conductive transition metals consisting of large groups of carbides, nitrides, or carbonitrides, while PDMS has inherent biostability and biocompatibility. Various MXene-based electrodes compositions (15% and 20% Mxene content) were prepared and evaluated for their potential in neural sensing. The samples were subjected to a series of characterization techniques such as Electrochemical Impedance Spectroscopy (EIS), Cyclic Voltammetry (CV), mechanical, long-term stability, biocompatibility biosignal sensing from the skin. The experimental results showed that the Compositions exhibited promising bulk impedances of 280 Ω and 111 Ω, conductivities of 0.462 mS/cm and 1.533 mS/cm. The CV testing revealed promising electrochemical stability of the compositions and the charge storage capacities were 0.665 mC/cm2 and 1.99 mC/cm2. Through mechanical testing the Young’s moduli were found to be 2.61 MPa and 2.18 MPa respectively. The composite samples have elongated by 139% and 144% respectively. The long-term stability test was done via PBS immersion of samples for over 8 weeks. The results exhibited a reduction in the impedances for the prepared samples in general. CV revealed the electrochemical stability with an increase in CSC. ECG and EMG testing showed excellent results when compared with commercial electrodes, hence, promising potential for flexible biosignal sensing applications.College of EngineeringCollege of Arts and SciencesMultidisciplinary ProgramsMaster of Science in Biomedical Engineering (MSBME
Semantic based navigation and lane keeping
No full textA Master of Science thesis in Mechatronics Engineering by Abdallah Adel Abdeen entitled, “Semantic based navigation and lane keeping”, submitted in April 2023. Thesis advisor is Dr. Shayok Mukhopadhyay. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).This thesis develops a novel method of robotic navigation and lane keeping system for the outdoor environment. The system uses semantic information, that is knowledge of a given map, and camera-based object detection of landmarks on the map. This allows any robot/vehicle to identify its approximate location on the map without using any beacon-based sensors, but only using semantic data obtained from a single RGB camera. This approach also does not use any estimation algorithm. The approach combines artificial intelligence-based object detection along with path planning algorithms, to provide a user a path from one point of the map to another. The lane keeping portion of the algorithm follows road lane markings until the directions from the semantic navigation algorithm leading the user/robot/vehicle to its destination. This system can be used for navigation onboard vehicles where the driving is done by a human, or the navigation system can be plugged into the lane keeping system of an autonomous vehicle, for achieving autonomous driving capabilities onboard a robot or an autonomous vehicle. This work presents results showing that future navigation tasks can be made less dependent on requiring a multitude of sensing and computing hardware, in environments where reliable and high-quality maps are already available. This has the potential to make navigation for autonomous driving in urban areas less expensive, as requiring a suite of LIDAR/RADAR, imaging, precision GPS sensors; and fusing all the data together – as prevalent on current autonomous vehicles, is very expensive. Additionally, robots that are reliant on GPS sensors are very reliant on their connection with satellites, which can often fail. Our proposed method aims to create a self-sustained system with reduced costs by relying on visual data obtained from an inexpensive camera and using image processing and artificial intelligence to achieve a visual positioning system. Object detection was used as the main backbone of this system and from within our tests, 8 false positives were detected out of 9000 images, which is a promising result for building detection.College of EngineeringMultidisciplinary ProgramsMaster of Science in Mechatronics Engineering (MSMTR
Cost Evaluation of 3D Concrete Printing in the UAE Construction Industry
No full textA Master of Science thesis in Construction Management by Mhd Amjad Alhomsi entitled, “Cost Evaluation of 3D Concrete Printing in the UAE Construction Industry”, submitted in November 2023. Thesis advisor is Dr. Adil Kahwash Al-Tamimi and thesis co-advisor id Dr. Ghanim Kashwani. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).The integration of 3D Concrete Printing (3DCP) in the construction sector is rapidly expanding, poised to revolutionize conventional processes and usher in disruptive technologies. Globally, the construction industry is actively exploring automated construction technologies, with a particular focus on the burgeoning capabilities of 3DCP. This technological shift not only enhances efficiency and reduces costs in construction projects but also extends its reach into realms beyond Earth, as evidenced by its application in building space habitats. This paper delves into case studies that meticulously demonstrate the invaluable impact of integrating 3DCP in the United Arab Emirates (UAE) construction industry. The discussion sheds light on diverse 3D Concrete (3DC) printers, each distinguished by unique attributes such as weight, price, building envelope, layer thickness, and more. While these factors remain immutable, the strategic selection of a 3DC printer at an optimal price point holds the key to substantial cost reduction in the final product. The primary objective of this thesis is to empower Small and Medium-sized Enterprises (SMEs) in the UAE to make informed decisions when selecting a 3DC printer. Three carefully chosen printers from different manufacturers, widely available and easily deliverable, undergo rigorous evaluation through a cost analysis using the Delphi-Analytical Hierarchy Process (AHP) method, a Multicriteria Decision-Making (MCDM) technique. The research addresses decision-making challenges through Google Form questions, employing the AHP approach on the Saaty scale of 0–9 points. Supplemented by a thorough literature review on the challenges faced by SMEs in adopting 3DCP and an insightful interview with a construction professional from an SME, the research identifies the most crucial criteria for the second level in the AHP method. In the culmination of this comprehensive analysis, the research unequivocally asserts that CyBe Construction Robot Crawler (RC) emerges as the pinnacle 3DC printer. Offering SME decision-makers a harmonious blend of cost-effectiveness and feature-rich capabilities, CyBe RC stands as the optimal choice in the dynamic landscape of 3DCP.College of EngineeringMultidisciplinary ProgramsMaster of Science in Construction Management (MSCM
Identifying the Factors Impacting Bridge Deterioration in the GCC
No full textA Master of Science thesis in Civil Engineering by Rawan Abdullah Al-Rashed entitled, “Identifying the Factors Impacting Bridge Deterioration in the GCC”, submitted in April 2023. Thesis advisor is Dr. Akmal Abdelfatah and thesis co-advisor is Dr. Sherif Yehia. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Bridge management systems (BMS) are one of the effective tools that can efficiently help in managing bridges at both project and network levels. A BMS usually contains four basic modules, which are database, maintenance cost, deterioration, and decision making and optimization. The deterioration module is a crucial component since it predicts the future condition of the bridge. The development of BMS within the GCC is still in its infancy and there are almost no well-developed deterioration models for bridges. The aim of this research is to identify the factors that could be considered while developing deterioration models within the GCC countries. To best identify these factors, the research was performed in three stages. In the first stage, a review of literature has been conducted to investigate the factors that have been adopted in deterioration models around the world. This review has revealed 33 factors adopted in different deterioration models. After filtering the factors to include only the ones that can be applicable in the GCC countries, a list of 27 factors has been identified. This list has been utilized in an interview targeting bridge experts to select; based on their experience, the factors that contribute to bridge deterioration and assign each factor a weight that represents its impact on bridge deterioration. In the third phase, the list of factors identified by the experts has been included in a survey that was distributed to bridge engineers to identify the final selection and rank the factors according to their importance level. Based on the relative importance index, the final results indicate that steel reinforcement protection, design load, chloride attack, type of defect, and age are the most important factors impacting bridge deterioration in the GCC.College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE
A knowledge-based perspective on the professionalization of SMEs: A systematic literature review and future research directions
No full textThis paper provides a synthesis of theoretical and empirical work related to the professionalization of small and medium-sized enterprises (SMEs) from a knowledge-based perspective.
A systematic literature review consisting of three major steps of planning, conducting, and reporting is conducted. Articles are identified, selected, and deductively coded. Quantitative and qualitative methods are employed to analyze the articles. The finalized list includes 78 articles and 48 journals, with the oldest article published in 1980 and the most recent articles published in 2022.
The findings showed that the empirical works (n=69) outnumbered the conceptual works (n=9). Most articles focused on the organizational level of analysis and identified causal conditions, modes, intervening conditions, and consequences. A multidimensional characteristic of professionalization emerged inductively as an additional attribute.
This paper provides a synthesis of the current literature and offers a research agenda to academics and practitioners interested in the professionalization of SMEs from a knowledge-based perspective
Finite Element Modelling of FRCM-Confined RC Columns Exposed to Fire
No full textA Master of Science thesis in Civil Engineering by Reem Talo entitled, “Finite Element Modelling of FRCM-Confined RC Columns Exposed to Fire”, submitted in June 2023. Thesis advisor is Dr. Farid Abed and thesis co-advisor is Dr. Ahmed El Refai. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).Externally bonded fiber-reinforced polymers (FRP) have been widely used for strengthening and retrofitting applications. However, their efficacy is hindered by the poor resistance of epoxy resins to elevated temperature and their limited compatibility with concrete substrates. To address these limitations, fabric-reinforced cementitious matrix (FRCM), also known as textile reinforced mortar (TRM), systems have emerged as an alternative solution. This thesis presents the development of three-dimensional (3D) finite element (FE) models using ABAQUS software to investigate the performance of FRCM-confined RC columns exposed to fire. A parametric study was conducted to examine the behavior of confined columns under various conditions. The parameters studied include the concrete clear cover (40, 50, and 60 mm), the number of poly-paraphenylene benzobisoxazole (PBO) FRCM layers (0, 1, and 2 layers), the presence of a 30 mm thick insulation layer, and axial preloading. Numerical analysis revealed key findings. Increasing the concrete clear cover from 40 to 50 and 60 mm resulted in reductions of steel reinforcing bar temperatures by 14 and 27%, respectively, after 1 hour of fire exposure. Moreover, the inclusion of a 30 mm insulation layer reduced steel bar temperatures by 70% compared to uninsulated columns. Increasing the number of FRCM layers did not significantly affect load resistance duration, but increasing the preloading level significantly reduced the duration of load resistance. In addition to the numerical study, preliminary experimental tests were performed on PBO-FRCM confined cylinders subjected to different target temperatures (100, 400 and 800 °C) with different concrete strengths (30, 45, and 70 MPa) and number of FRCM layers (0,1, and 2). The experimental results highlighted the confinement effect of FRCM, particularly in cylinders with lower concrete compressive strength. Cylinders exposed to 100 °C exhibited a slight increase in strength, while no specific trend was observed in the variation of the compressive strength for cylinders heated to 400 °C. Specimens heated up to 800 °C experienced a significant reduction in strength, reaching up to 82%.College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE
CFRP Strengthening of Pre-damaged Fiber Reinforced Recycled and Lightweight Concrete Beams
No full textA Master of Science thesis in Civil Engineering by Michael AbdelMessih entitled, “CFRP Strengthening of Pre-damaged Fiber Reinforced Recycled and Lightweight Concrete Beams”, submitted in April 2023. Thesis advisor is Dr. Sherif Yehia. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form).College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE
World society and the convergence of consumer values: Buying patterns of eco-certification in the UAE
No full textEco-certifications offer consumers the opportunity to vote with their money for more sustainable methods of production. While consumer-facing eco-labels are mostly recognized and consumed in western countries little is known about their performance in expat societies. This study applies world society theory to a sample of Arab, Western, and South Asian United Arab Emirates (UAE) residents to test whether globalization causes assimilation of familiarity, attitudes, and buying frequencies for major eco-labels. The results show that respondents with Western ethnicities are more familiar with eco-certifications. However, Arab, and South-Asian citizens report similar or higher levels of importance for the purported benefits of eco-certifications. Among respondents familiar with eco-certification, we found no differences in buying frequency by ethnic group. Findings related to ethnicity support world society theory because social, environmental, and quality ideals converge among different ethnic groups in the UAE