Engineering Commons^™

Itraconazole Nanocomposites Prepared Via Rotary Evaporator Drying Of Nanomilled Suspensions, Alexander Santos Coelho

Theses

The aim of this study is to explore the feasibility of rotary evaporation for drying wetmilled drug suspensions as a novel approach to produce drug nanocomposites that exhibit fast redispersion and immediate drug release. To this end, the physical stability of the nanomilled itraconazole (drug) suspensions, a.k.a., nanosuspensions, during the milling and storage; the drying of the itraconazole nanosuspensions via the rotary evaporator; and the type/loading of various polymers/surfactants (dispersants) on aqueous redispersion and drug release from the nanocomposites were examined. Our results suggest that smaller drug particle size, owing to nanomilling, and smaller nanocomposite particle size, owing to optimized …

Flexible Microfluidic Device With Nonplanar Interdigitated Microelectrodes, Saud Alssaidy

Theses

The lab-on-a-chip concept has improved significantly in recent years to meet global demand for various applications with the advent of new technologies. Much progress has been achieved, but many microfluidic devices still suffer from design limitations in terms of sensitivity and selectivity because they use rigid, fragile substrate materials and conventional electrodes, which do not provide high sensitivity or selectivity and suffer from signal-to-noise ratio issues. This work proposes a novel device architecture that uses flexible, transparent top and bottom layers integrated with (nonplanar interdigitated microelectrodes) to create a sandwich-like flexible substrate base. The top and bottom layers consist of …

Towards Automation Of Aluminum Cell Ramming Process, Maryam Salem Mohamed Alkaabi

Theses

Newly installed cathode blocks in an aluminium reduction cell, expand due to a rapid increase of temperature when passing a high current at the start-up of the cell. High thermal stresses may result if cathode blocks are lined without gaps, and this can lead to cracking of the cathodes and failure of the cell. On the other hand, leaving gaps would cause failure due to molten metal infiltration in the gaps. To overcome these problems carbon-based ramming material is used to fill these gaps. Currently ‘Filling’ is carried out manually or partially automated, but this needs to be fully automated …

Immobilized Lipase On Zif For Enhanced Biofuel Production, Reem Mohammed Al Mansouri

Theses

Enzymatic transesterification of triglycerides to produce biodiesel has been gaining increasing attention owing to its advantages over chemical processes. Being catalysts, enzymes are not consumed during the processes in which they are used. Therefore, a successful technique to allow their repeated use can significantly enhance the economic feasibility of the process. The most common approach to allow easy separation of the enzymes and to eliminate their wastage is immobilization on a support matrix. Recently, Metal-Organic Frameworks (MOFs) have been suggested as preferable support for enzyme immobilization, owing to their high-order structure and high porosity and specific surface area. This thesis …

The Impact Of Wastewater Chemistry And Flow Characteristics On Hydrogen Sulfide Concentration, Mohsina Muhammed Sherief

Theses

Hydrogen sulfide (H₂S) is a naturally occurring, highly toxic gas that is formed from the decomposition of sulfur compounds. At low concentrations, H₂S is an irritant for the eyes, respiratory and gastrointestinal tract. At higher H₂S concentrations, it produces neurological impairment with dizziness, headache, and loss of consciousness. Mortality was reported to reach 6 percent following exposure to elevated concentrations. H₂S is generated in different industrial processes. In wastewater collection and treatment plants, H₂S is a common source of concrete and metal corrosion that has resulted in huge economic loss. …

Minimization Of The Weld Distortion By Weld Sequence Optimization Using Artificial Intelligence, Jeyaganesh Devaraj

Theses

The application of dissimilar metal welding processes is increasing nowadays in the automobile, aerospace, marine industry as they not only serve for joint welding for different metals but also assist in repairing and reworking in a simplified manner. Study on optimization of weld parameter to weld a structure is important to have control over the distortion, mass deposition, tensile strength, etc. The present research reports the development and implementation of the Genetic algorithm integrated Artificial Neural Network (GANN) based weld sequence optimization for reducing deformation of dissimilar metal joining using the hot-encode technique. Gas Metal Arc Welding (GMAW) is used …

Split-Horizon Dual-Stage Dispatch Scheme For A Standalone Microgrid, Aslam Amir

Theses

The advent of microgrids has prompted plenty of studies into its design, control, protection, and implementation, with several operational as well as pilot systems being commissioned worldwide. This necessitates the development of hardware and software for the Energy Management System, the supervisory controller in a microgrid. Hence, this thesis provides a novel dual-stage dispatch scheme for the Energy Management System of a Standalone microgrid by “splitting” the dispatch time horizon into four equal quarters to facilitate better usage of power forecast accuracies. The two stages include Unit Commitment/Scheduling and Economic Dispatch for the dispatchable Distributed Energy Resources based on renewable …

Immobilization Of Lipase On Metal Organic Frameworks For Biodiesel Production, Reem L Safwan Shoma

Theses

For the economical application of enzymatic processes in biodiesel production, lipase enzyme has to be used in immobilized form to allow easy retention and reuse. The main challenges facing the industrialization of the enzymatic process are the high mass transfer resistance, the tendency to adsorb the by-product glycerol onto the support matrix and poor operational stability. These problems can be solved by a good selection of supports of favourable surface characteristics and pore sizes. In that regard, increasing interest has recently been in Metal-Organic Frameworks (MOFs) as a new kind of porous support for enzyme immobilization. Physical adsorption, which is …

Strengthening Of Concrete Deep Beams Using Carbon Fabric Reinforced Cementitious/Geopolymeric Matrix, Nour Mohamed Muhsen Khir Allah

Theses

This research aimed to examine the effectiveness of using carbon fabric-reinforced matrix (C-FRM) composites to improve the shear response of reinforced concrete (RC) deep beams. Ten RC deep beams with a/h of 1.6 were tested, where a is the shear span and his is the beam depth. Test parameters included the presence of internal shear reinforcement (no shear reinforcement and minimum shear reinforcement), number of C-FRM composite layers (one and two layers), angle of inclination of the second layer of CFRM (90o and 0o with respect to the longitudinal direction of the beam), and type of matrix (cementitious and geopolymer). …

Flutter Suppression By Active Controller Of A Two-Dimensional Wing With A Flap, Abdallah Tarabulsi

Theses

Flutter is a divergent oscillation of an aeroelastic structure, and one of a family of aeroelastic instability phenomena, that results from the interaction of elastic and inertial forces of the structure with the surrounding aerodynamic forces. Airfoil Flutter is important due to its catastrophic effect on the durability and operational safety of the structure. Traditionally, flutter is prevented within an aircraft's flight envelope using passive approaches such as optimizing stiffness distribution, mass balancing, or modifying geometry during the design phase. Although these methods are effective but they led to heavier airfoil designs. On the other hand, active control methods allow …

Material Characterization For Microwave Absorbing And Shielding Applications, Muhammed Shafeeque Kallumottakkal

Theses

The rapid advancement and widespread of microwave and RF-communication systems have contributed to an abundant rise in electromagnetic energy radiation in our living environment. Such an increase in microwave sources is due to the development and advancement in communication techniques (mobile phones, laptops, and antennas for aeronautics or automobile) and electronic warfare in the military field (radar and satellite). To address these concerns, EM absorbing materials are used to ensure public safety and the safety of military operations. Various types of EM absorbing materials made up of composite materials have been produced and studied. This thesis discusses the microwave properties …

Biosensor Devices Based On Graphene And 2d Materials, Suhada Poovathy

Theses

Nanomaterials offered new improvements and developments to the bio-sensing field due to their unique physical and chemical properties. Unique and exceptional electronic properties, such as the ultrahigh surface-to-volume ratio and the excellent electrical properties of the 2D materials like in graphene, making these materials promising for future smaller and faster electronics, but an extensive amount of research is still needed. This thesis is concerned with the study of the integration of 2D material graphene in the development of sensitive and rapid biosensors. The main objective of this thesis is to understand the features and characteristics of graphene, evaluate the scope …

Environmental Assessment Of The Impact Of Land-Based Discharges On Marine Water And Sediment Quality In Dubai, Uae, Ayman Fathy Halawa

Theses

The current seawater and Creek – Canal waterway in the Emirate of Dubai, UAE, is under tremendous pressure because of continuous urban water discharges from land-based sources. Therefore, the impact of urban water discharges on marine water and sediment quality in the Emirate requires a thorough assessment. The main objective of this study is to assess the impacts of effluent discharges on the quality of water and sediment in the open sea and Dubai Creek. The land-based sources include the power and desalination plants, industrial sector, sewage treatment plant, and stormwater runoff. To achieve the stated objective, relevant data on …

Drug Releasing Hydrogels For Opioid Use Disorder, Kaytlyn M. Crowe

Theses

Ease of access to prescription opioids and the strength of synthetic opioids have contributed to the rise in over use disorders, overdose, and death rates during the opioid epidemic. The current overdose standard of care, rescue NLX (NLX), is a competitive antagonist to the μ-opioid receptor but has a relatively short period of action compared to opioid agonists, especially synthetic agonists. Rises in the abuse of these synthetic and semi-synthetic agents in recent years have shown the weaknesses of rescue NLX, as it can leave overdose patients vulnerable to renarcotization and precipitated withdrawal. To prevent both from occurring, we developed …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 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 …