Engineering Commons^™

Assimilating Requirements Specification For Space Manned Missions: A Novel Approach, Khalfan Mohamed Al Remeithi

Theses

Aligned with the UAE Space Strategy 2117, which aims to establish the first inhabitable human on the Martian Surface by 2117, and with the current enthuse toward space tourism, the thesis proposes a novel framework to assimilate the process of requirement specification for a Manned Mission to Mars surface. Deep Space manned missions are unique and characterized by a set of specific requirements that should be elicited from different sources and stakeholders to ensure the missions’ success. In addition, these missions are highly dependent on the software components in the Command and Data Handling System (CDHS), which is used to …

Heat Transfer Intensification In Microchannel Heat Sinks (Mchs) - Wavy Channels Embedded With Pin Fins, Anas Mohammad Amin Alkhazaleh

Theses

This work conceptualizes heat sinks for electronics employing wavy/sinusoidal microchannels embedded with pin fins and subsequently analyzes their performance in terms of thermal resistance, pressure drop, maximum chip temperature, and the associated pumping power due to the pressure drop. The conceptualized wavy Microchannel Heat Sink (MCHS) is mathematically modeled using a combination of governing equations including energy equations, continuity equations, and Navier- Stokes equations. The performance of the wavy microchannel heat sink embedded with pin fins is evaluated based on a parametric study covering multiple parameters; microchannel’s amplitude, frequency, hydraulic diameter, pin fins’ diameter, and location, and Reynolds number. The …

Comprehensive Characterization Of The Aerosol And Cloud Condensation Nuclei In The Uae, Farah Hassan Abdi

Theses

Cloud seeding has emerged as a significant alternative freshwater source in the United Arab Emirates (UAE). It is employed to manipulate weather conditions and increase precipitation in specific target regions. These efforts aim to densify clouds and enhance the likelihood of rainfall by inducing nucleation. This technique involves an operational crew aboard an aircraft that disperses substantial quantities of seeding particles, such as salts or silver iodide, into suitable clouds. These particles can serve as cloud condensation nuclei (CCN) and indirectly affect the rate of rainfall. In 2018, cloud seeding operations were responsible for approximately 10-15% of the UAE's total …

Extraction And Bioactivity Evaluation Of Antioxidant Components From Teucrium Stocksianum Bioss Collected From Uae, Ahmad Ayman Al Salloum

Theses

Recently, the industry of Natural Bioactive Compounds (NBAC) is expanding dramatically due to its high medical potentials. High bioactivity of natural extracts from a wide range of plants is evident from the reported literature. For instance, NBACs show antibacterial, antifungal, antimicrobial, anti-inflammatory, anticancer and antioxidant activities. Teucrium stocksianum Boiss. from the Lamiaceae family is a known herb in the traditional medicine in United Arab Emirates. Multiple bioactivities of T. stocksianum were recorded such as anti-inflammation, analgesia, antioxidation, anticancer, antinociception and antimicrobial bioactivity. In this thesis, the extraction of NBACs from T. stocksianum was studied with Microwave-assisted extraction using Deep eutectic …

Study Of Electrodeposition Of Copper-Indium Material For Fabrication Of Cis Thin-Film Solar Cells, Leher Farooq

Theses

Abstract

Copper-Indium material for the fabrication of CIS/CIGS thin-film solar cells and for applications as an alloy is one of the most auspicious materials currently being studied and has attracted significant interest in solar energy and other industries. In the past, there have been several methods used for the fabrication of chalcopyrite thin-film solar cells. However, one of the best methods in the industry is electrodeposition, which employs the principles of electrochemistry to deposit materials on a working electrode. The cyclic voltammetry and constant potential deposition studies have been conducted for the electrodeposited copper indium material. In order to better …

The Effects Of Design Parameters On The Neural Recordings With Micro-Ecog Arrays, Manan Amish Sethia

Theses

In the field of neural prosthetics, electro-cortico-graph (ECoG) arrays are commonly used to record neural activity of the brain cortex both in animal and human subjects. A finite element model (FEM) was developed to simulate the electric field generated by a single neuron in the rat brain cortex and a micro ECoG array (µECoG) placed on the pia surface for recording the neural signal. The neuron was simulated as a dipole current source with a magnitude of 1µA and placed at three different depths in the motor cortex corresponding to different layers under the µECoG array. The array design was …

Iii-Nitride Ultraviolet Light-Emitting Diodes: Approaches For The Enhanced Efficiency, Moulik Patel

Theses

III-nitride ultraviolet (UV) light-emitting diodes (LEDs) offer marvelous potential for a wide range of applications, including air/water purification, surface disinfection, biochemical sensing, cancer cell elimination, and many more. III-nitride semiconductor alloys, especially AlGaN and AlInN, have drawn significant attention due to their significant advantages that include environmental-friendly material composition, compact in size, longer lifetime, low power consumption, and tunable optical emission. However, the performance of III-nitride UV LEDs in terms of efficiency and output power is still deficient. The presence of high defects and dislocations due to lattice-mismatched epilayers, polarization induced quantum-confined Stark effect, electron overflow with low hole injection …

Real Time Analysis Of Eye Movements Using Computer Aided Software, Farhan Ahmad

Theses

Eye movement analysis is a slow and tasking job that require a trained vision analyst to sift through hundreds of eye movements. The difficulty of the task increases when a subject has undiagnosed eye related disorders. One such disorder is Convergence insufficiency (CI) which affects nearly 12 million people in the US. Convergence insufficiency occurs when the eyes are unable to coordinate simultaneous inward movement for near focal tracking. Individuals with CI are unable to coordinate eye movements this can result in many symptoms such as double vision, blurred vision, headaches, vision strain, and fatigue. A diagnosis for CI relies …

Performance Of Ultrasound-Assisted Forward Osmosis Membrane Process In Desalination Of Seawater, Bara Awwad Al-Sakaji

Theses

The objective of this study was to investigate the effect of using ultrasound on water flux through forward osmosis membrane when applied for seawater desalination. A synthetically prepared solution simulating seawater characteristics was used. Parameters considered in the investigation included membrane cross-flow velocity (0.25 and 1.0 cm/s), flow configuration (co-current versus counter-current), direction of ultrasound waves relative to the membrane side (active layer versus support layer), and type of draw solution (NaCl versus MgCl₂). Furthermore, a two-level factorial design was considered in the analysis of the results obtained from the experimental work. This study revealed that applying a …

Scenario-Based Simulation Of Treatment Processes For Minimization Of Sludge Production From Al-Saad Wastewater Treatment Plant, Omar Gamil Abdelmajeed Hussien

Theses

The biological-activated sludge treatment process is the most widely used approach to treating domestic wastewater. It involves the transformation of soluble and particulate organic matter to gases and large amounts of settleable biomass (produced sludge). This sludge is considered one of the most pressing management challenges since its treatment represents approximately 50 to 60% of the total operational cost of a wastewater treatment plant (WWTP). The traditional management of excess sludge is by disposal in landfills, incineration, or agriculture reuse in the form of fertilizers but due to energy and environmental concerns, many jurisdictions developed strict policies and regulations for …

Performance Evaluation Of Cement-Free Geopolymer Concrete Made With Recycled Concrete Aggregates And Steel Fibers, Jamal Ahmad Samer Medljy

Theses

Sustainable and innovative alternatives have been investigated to replace concrete’s main components, natural aggregates, and cement. Previous studies have been carried out to replace NA and cement with recycled concrete aggregates (RCA) and inorganic alkali-activated geopolymer binders, respectively. Yet, such sustainable concrete has only been proposed for non-structural purposes, owing to the inferior properties of RCA. This research work aims to assess the feasibility of reutilizing RCA from construction and demolition waste and locally available industrial solid by-products in the production of sustainable geopolymer concrete for structural applications. The binding materials were either in the form of a single precursor, …

Numerical Investigation Of Mesh-Based Enhancement Of Vapor Bubble Condensation, Omar Darwish Ali Alqadi Alhammadi

Theses

The aim of this work is to study the vapor bubble condensation process and the enhancement technique via affecting bubbles dynamic using a mesh-based structure. The bubble dynamics and thermal behavior are studied by considering the heat and mass transfer through the bubble’s interface area between the vapor and liquid regions and the resulting condensation effects. The thermal characteristics of bubbles are observed considering the initial and final liquid temperatures. Additionally, the bubble dynamics are studied in terms of several parameters including the relative velocity of the bubble, bubble deformation, interfacial area, and the bubble diameters. The relation between the …

Bending-Torsion Flutter Analysis Of A Viscoelastic Tapered Wing Carrying An Engine And Subjected To A Follower Thrust Force, Youssef Shaaban Abdelfattah Matter

Theses

Flutter, a dynamic divergent instability, is one of the significant phenomena of Aeroelasticity. This dangerous aeroelastic phenomenon can occur to any flexible structure subjected to aerodynamic forces such as aircraft wings, bridges, buildings, etc. It is important to analyze the flutter in order to predict the speed and frequency at which it occurs so that structural damages and failures can be avoided. This thesis is concerned with non-dimensional parametric modeling of the flutter of a viscoelastic tapered wing with an attached engine. The main objectives of this thesis are to determine regions of stability and boundaries of flutter speed and …

Thermo Hydraulic Performance Of Polymer Double-Pipe Heat Exchanger For Single-Phase Heating/Cooling Application, Ahmed Mohamed Gafar

Theses

This thesis details the model-based study carried out for understanding the thermal and hydraulic performance of double pipe heat exchangers with and without pin-fins; both counter and parallel flow configurations are considered in the study. The pin-fins are located on the outer wall of the inner pipe thereby extending into the annulus and in this study, the hot fluid is assumed to pass through the annulus. The model consists of multiple governing equations such as continuity equations, Navier-Stokes equations, and energy equations. A fluent module of Ansys Workbench is used for conducting the model-based study. Double pipe heat exchangers constructed …

Electrodeposition Study Of Alloys For Solar Energy, Corrosion Resistance, And Battery Applications, Thaier Tawfeek Alawadh

Theses

Copper-Zinc-Tin sulphide (CZTS) compound is one of the alloys, which has significantly caught the attention of a considerable number of researchers since the beginning of the century. Consequently, academic laboratories started investigating the alloy in-depth with its various combination due to its valuable applications with high potential usage. The CZTS alloy has a high tendency to replace the current copper indium gallium selenide (CIGS) thin-film solar cell system due to scarcity of CIGS components, and toxic manufacturing procedures compared to CZTS. Nevertheless, CZTS is a new studied compound with exceptionally low photovoltaic empirical efficiency and an inadequate understanding of its …

Development Of Piezoelectric Energy Harvesting System For Low-Frequency Vibrations, Mai Rabie Mahmoud Ismail

Theses

Harvesting energy from vibration sources has attracted the interest of researchers for the past three decades. Researchers have been working on the potential of achieving self-powered MEMS scale devices. Piezoelectric cantilever harvesters have caught the attention in this field because of the excellent combination of high-power density and compact structure. The main objective of this thesis is to develop a novel and optimum piezoelectric harvester system using lumped parameter model (LPM) for given vibration sources. The finite element model (FEM) is used in this work as an original approach to be utilized for optimal design optimization. Three types of validations …

Modelling And Control Of A Two-Link Rigid-Flexible Manipulator, Rahma Saeed Rasheed Alnajjar

Theses

The literature lacks data on the reliability of 3D models created by Autodesk Inventor software and imported to MATLAB Simulink software in comparison to mathematically generated models. In this contribution, a two-link rigid-flexible manipulator modelled in two different methods was demonstrated, one of which is using Lagrange equations and Finite Element Method to generate a mathematical model of the manipulator, and the other is creating a 3D model with the aid of Autodesk Inventor then import to MATLAB Simulink, both models were subsequently controlled by three types of controllers, conventional PID controller, LQR controller, and LQG controller. The research demonstrated …

Performance Of Cement-Free Geopolymer Concrete Made With Ceramic Waste Powder Using Taguchi Method, Ponalagappan Chokkalingam

Theses

The ceramic industry produces a substantial amount of waste during its production processes. Recycling and reutilizing such ceramic waste is a challenge due to its extended biodegradation period. Consequently, the ceramic industry is dedicated to attaining a sustainable solution to dispose of this waste rather than discarding it wastefully into landfills or stockpiles. In turn, the demand for ordinary Portland cement has been on a steady increase, leading to concerns about the sustainability of the construction industry. As a sustainable alternative to cement, alkali-activated binders have been proposed owing to their ability to reduce carbon emissions, preserve nonrenewable natural resources, …

Development Of Heat Insulation Composite Materials Based On Bio-Polyesters And Natural Filler, Hyder Ali Reyah Al Abdallah

Theses

The increasing waste - bio or synthetic - is a critical issue, and managing this waste is a huge challenge for industry and academia. The use of biodegradable materials is sought as an eventual factor in decreasing the current level of waste generation. Therefore, one of the main research areas nowadays is to develop bio-composite materials over fuel-based materials where the bio-composites or waste-based composites serve several advantages both environmentally and economically, including the biodegradability feature of the bio fillers, and the affordability due to its abundant presence in nature. Bio-waste, specifically from agricultural sources, can be used as fillers …

Behavior Of Steel Fiber-Reinforced Geopolymer Concrete Made With Recycled Concrete Aggregates, Abdalla Ahmed Moallim Hussein

Theses

Industrial by-products and recycled concrete aggregates (RCA) have the potential to fully replace cement and natural aggregates, respectively, in the production of concrete rather than being discarded wastefully into landfills or stockpiles. Yet, their combined use in the development of a novel RCA geopolymer concrete has been limited to nonstructural purposes, owing to the inferior mechanical and durability properties of said concrete. To improve the properties of geopolymer concrete made with RCA, steel fibers may be added to the mix. This research aims to study the feasibility of reutilizing locally available industrial solid wastes and RCA in geopolymer concrete for …

Material Handling System For An Advanced Flexible Manufacturing Environment, Con Cronin

Theses

A Flexible Manufacturing System (FMS) is a method of production that is designed to easily adapt to changes in the type and quantity of the product being manufactured. Machines and computerised systems can be configured to manufacture a variety of parts and to handle the changing levels of production that is required. The aim of this project was to investigate the current manufacturing processes of Kostal Ireland GmbH with the aim of developing a bespoke prototype material handling system to achieve flexible manufacturing. Kostal Ireland GmbH currently do not have the ability to change their manufacturing operations easily when a …

Adaptive Uplink Data Rate Prediction And Networkselection In A Vehicular Mobile Channel, Georgi Nikolov

Theses

The rapid acceleration into the digital age brings a worldwide interconnectedness of an unprecedented level. This interconnectedness transforms the modern transportation network by linking its infrastructure components (e.g., signaling systems, traffic control systems, maintenance systems) together. Intelligent transportation systems (ITS) can utilize this newly emerged network infrastructure, improving traffic safety, traffic control, and reducing transportation-related environmental impacts, changing the way drivers, businesses and governments deal with road transport. It is expected that in the near future self-aware vehicles (e.g., trains, cars or trucks) will constitute the majority of the transportation infrastructure. Vehicles need to be able to reliably communicate critical …

Optimisation Of Grass Measurement Technologies Through Field Experimentation And Numerical Simulation Methods, Darren Joseph Murphy

Theses

Maximising pasture utilisation through optimal grassland management is vital in terms of ensuring the economic sustainability and mitigating the environmental impact of both Irish and global pasture-based livestock production. Frequent and accurate measurement of grass quantity and quality is one of the main methods of maximising grass production and utilisation on pasture-based farms. The most prominent grass measurement tool used on Irish pasture is the rising plate meter (RPM), however, there are a range of issues with this method including operator bias, precision and difficulties in accounting for spatial variation. Currently, there is no definitive protocol for grass measurement which …

Neurovascular Catheter Measurement System Development For Process And Design Effect Evaluation, Cathal Tadhg Merz

Theses

Neurovascular guide catheters are used to treat problems affecting blood vessels within the brain through minimally invasive procedures. Catheters are inserted into the patient via their femoral or brachial arteries and manually navigated to the brain to deliver treatment. This procedure replaces the requirement to cut into the patient’s skull and brain tissue but is limited by reduction of blood vessel lumen diameter and increase in tortuosity of blood vessels deep in the brain. During these procedures, catheters can sometimes fail by kinking or fracturing into two pieces. The rate of failure by fracture of a particular neurovascular catheter device …

Treated Hfo2 Based Rram Devices With Ru, Tan, Tin As Top Electrode For In-Memory Computing Hardware, Yuvraj Dineshkumar Patel

Theses

The scalability and power efficiency of the conventional CMOS technology is steadily coming to a halt due to increasing problems and challenges in fabrication technology. Many non-volatile memory devices have emerged recently to meet the scaling challenges. Memory devices such as RRAMs or ReRAM (Resistive Random-Access Memory) have proved to be a promising candidate for analog in memory computing applications related to inference and learning in artificial intelligence. A RRAM cell has a MIM (Metal insulator metal) structure that exhibits reversible resistive switching on application of positive or negative voltage. But detailed studies on the power consumption, repeatability and retention …

Incident Duration Time Prediction Using A Supervised Topic Modeling Method, Jihyun Park

Theses

Precisely predicting the duration time of an incident is one of the most prominent components to implement proactive management strategies for traffic congestions caused by an incident. This thesis presents a novel method to predict incident duration time in a timely manner by using an emerging supervised topic modeling method. Based on Natural Language Processing (NLP) techniques, this thesis performs semantic text analyses with text-based incident dataset to train the model. The model is trained with actual 1,466 incident records collected by Korea Expressway Corporation from 2016-2019 by applying a Labeled Latent Dirichlet Allocation(L-LDA) approach. For the training, this thesis …

Preparation And Characterization Of Reactive Composites Combining Boron With Mixed Oxides, Purvam Mehulkumar Gandhi

Theses

Thirteen liquids have been explored as Process Control Agents (PCAs) for high-energy mechanical milling of two metal oxide powders, CuO and Bi₂O₃, with the practical purpose to reduce the sizes of powder particles and refine their crystal structure. Multiple liquid properties have been considered to analyze their effect on evolution of both particle and crystallite sizes during milling for each oxide. Experimental data were analyzed using the δ-AICc (Akaike Information criterion) correlation function applied to linear relations between liquid properties and powder characteristics. Multiple linear correlation models were ranked based on the highest log-likelihood and the …

Cycloidal-Drive Joint Design For Wearable Exoskeletons, Abhi J. Rawal

Theses

This thesis's scope was to construct a highly back drivable and compact joint design that can be used for wearable exoskeletons specifically designed to assist with rehabilitation. A compact cycloidal gear transmission was designed to satisfy the compactness requirement while ensuring the minimum torque is required for backdriving the mechanism. The joint was designed based on the compact cycloidal drive specifications, and the backdrivability test was performed to measure the minimum torque required (1.20 Nm) to backdrive. The joint design incorporates various important features such as rotation lock feature to prevent hyperextension, a housing design that offers the benefit of …

Human Activity Recognition Using Wearable Sensors: A Deep Learning Approach, Jialun Xue

Theses

In the past decades, Human Activity Recognition (HAR) grabbed considerable research attentions from a wide range of pattern recognition and human–computer interaction researchers due to its prominent applications such as smart home health care. The wealth of information requires efficient classification and analysis methods. Deep learning represents a promising technique for large-scale data analytics. There are various ways of using different sensors for human activity recognition in a smartly controlled environment. Among them, physical human activity recognition through wearable sensors provides valuable information about an individual’s degree of functional ability and lifestyle. There is abundant research that works upon real …

Impact Of Different Environmental Conditions On The Thermo-Mechanical Characteristics Of Compacted And Non-Compacted Carbon/Epoxy Plain Weave Woven Laminated Composites, Maryam Hamad Helal Thabet Al Kuwaiti

Theses

Fibre-reinforced polymeric composites used for aerospace applications are subjected to different environmental conditions during their operational life, such as moisture and temperature, which can adversely affect their performance over time. On the other hand, the standard fabrication process of these composite aircraft components requires a certain level of in-process vacuum compaction during the composite lay-up process to ensure the escape of entrapped air between the composite layers to prevent the formation of voids, through the application of bleeders/breathers around the composite laminate known for creating a channel for air to escape through. The aim of this study is to evaluate …