Physical Sciences and Mathematics Commons^™

Electrical Properties Of Metal Semiconductor Contacts - Metals On Mos2: A Case Study, Xiao Chang

Theses

Properties of monolayer semiconductor, MoS2, are presented in the research. Schottky barrier height and Schottky-Mott rules are discussed. The current-voltage measurement and capacitance-voltage measurement are analyzed considering the role of the work function. We mainly focus on metal semiconductor contacts on molybdenum disulfide (MoS2). The properties of bulk and monolayer molybdenum disulfide are discussed. The differences between the bulk and monolayer, based on band gap structure theory, are presented. Utilizing the data obtained in the literature, the influence of temperature on the electrical properties of monolayer molybdenum disulfide are analyzed. In particular, the electrical properties of metals on MoS2 such …

Characteristics Of Different Deep Neural Networks And Application Of Pre-Trained Model Without Transfer Learning, Zhiqi Peng

Theses

Deep neural networks have been successful in many areas, some of them even surpass human performances. The goal of this thesis is using data simulations to present different characteristics of three deep neural networks: fully connected deep neural network, convolutional neural network, recurrent neural network, which will perform best when dealing with different feature patterns. By using these characteristics to design a deep neural network on top of an adopted pre-trained model with untrainable layers, achieved an averagely 11.1% improvement than a model with transfer learning method.

Looping Predictive Method To Improve Accuracy Of A Machine Learning Model, Subramanyam Reddy Pogili

Theses

The topic of this project is an analysis of drug-related tweets. The goal is to build a Machine Learning Model that can distinguish between tweets that indicate drug abuse and other tweets that also contain the name of a drug but do not describe abuse. Drugs can be illegal, such as heroin, or legal drugs with a potential of abuse, such as painkillers. However, building a good Machine Learning Model requires a large amount of training data. For each training tweet, a human expert has determined whether it indicates drug abuse or not. This is difficult work for humans. …

Exact Localized Solutions Of The Nonlinear Dirac Equation, Yaser Hasan Sabbah

Theses

The nonlinear Dirac equation is a relativistic classical field theory that describes the behavior of a system of self-interacting spinor fields. According to this theory, the interactions among spinor fields are represented by additional Kerr-nonlinearity added to the Dirac equation, which justifies and models the noticed solitonic behavior of the systems. There are various models of the nonlinear Dirac equation which differ from each other in the factors taken into account in the modelling, especially the mode of the coupling among the spinor fields as well as the nature of the system represented by the model. In this present thesis, …

Comparative Degradation Of Emerging Pollutants Using Chemical And Enzymatic Approaches, Khadega Abobaker Abudullarhman Al-Maqdi

Theses

Organic pollutants, especially those found in water bodies; pose a direct threat to various aquatic organisms as well as humans. A variety of different remediation approaches, including chemical and biological methods have been developed for the degradation of these organic pollutants. However, comparative mechanistic studies of pollutant degradation by these different systems are almost non-existent. In this study, the degradation of two emerging pollutants an antibiotic pollutant, Sulfamethoxazole (SMX) and a model thiazole pollutant, Thioflavin T (ThT), was carried out using advanced oxidation process (AOP), using UV+H2O2 or a peroxidase enzyme system. Optimization conditions for Sulfamethoxazole degradation by peroxidase enzyme …

A Field Study On Treating Wastewater Using Bioretention And Permeable Pavement Systems, Rubab Ammad

Theses

The wastewater treatment study was conducted as a part of the efforts initiated by the UAE government for combating water shortage in the country by adopting the strategy of water conservation and reuse. This study investigated the performance of two water sensitive urban design systems, the Permeable Pavement and the Bioretention System, in improving the wastewater quality from fish tanks. Conventionally, these systems are used for storm water treatment but as UAE is situated in an arid climatic zone and experiences minimal rainfall, the two systems in undertaken study have been used in treatment of wastewater to gage their performance …

Business-It Alignment In Higher Education Institutions: United Arab Emirates University Case Study, Nayla Salem Ali Al Khateri

Theses

This thesis addresses the importance of Business-IT alignment in higher education institutions. Business-IT alignment is defined as applying IT in a suitable and timely manner, in harmony with business strategies, goals and needs. Business- IT alignment is an ultimate goal of governmental and non-governmental organizations that requires close attention and continuous monitoring. UAE university has a well-defined business strategy augmented with a well-defined IT strategy. So, to get the most benefits of acquiring and using IT in the university, the IT need to be aligned with the core business and the supporting services. The main objective of this thesis is …

Evaluation Of Functionalized Magnetite Nanoparticles For The Removal Of Heavy Metal Ions From Aqueous Media, Khaula A. Ai Jahoushi

Theses

Sorption is one of the most efficient techniques for the removal of heavy metal ions from waste water. It involves the use of solid materials, known as sorbents, which can be natural of synthetic in origin. Recently, synthetic nanomaterials of various compositions have been used as sorbents. Among these materials, calcium phosphate; also known as hydroxyapatite (HAp), and magnetite were previously investigated as potential sorbents. In the current study, commercial HAp, and magnetite nanoparticles as well as their physical and chemical mixtures were investigated as potential sorbents for the removal of Cd2+ ions from simulated wastewater. A comparison is made …

2-D Electrophoresis Modeling Of Multienzyme Cutting Of Polypeptides, Howard Mayes

Theses

2-Dimensional Electrophoresis is one of the tools in the identification of proteins by molecular weight and pH. The display of molecular weight allows the researcher to quickly identify whether a specific protein or peptide string is in the sample. The pH measurement allows even better resolution between different species in the sample. The MultiEnzyme ElectroPhoresis (MEEP) program tries to model that by providing a graph that displays separated protein strings by both molecular weight and pH. The ability to cleave the protein with 43 different enzyme variations allows the researcher to analyze appropriate enzymes to isolate a protein subsequence before …

Vertical And Cross-Shore Distributions Of Barnacle Larvae In La Jolla, Ca Nearshore Waters: Implications For Larval Transport Processes, Malloree Lynn Hagerty

Theses

Many marine organisms begin their lives as tiny larvae that are at the mercy of ocean currents. Understanding the transport and subsequent dispersal of larvae is crucial, as it drives population connectivity in the ocean. Larval transport is a complex process involving both physical motions of the water and larval behavior. Vertical positioning is especially important because currents vary throughout the water column, and larvae at different depths will be advected differently. With swimming speeds insufficient to swim against currents, marine larvae can mediate cross-shore transport by controlling their depth distributions. Thus, the overall objective of this study was to …

Matrix Completion Algorithms With Applications In Biomedicine, E-Commerce And Social Science, Yiran Wang

Theses

This thesis investigates matrix completion algorithms with applications in biomedicine, e-commerce and social science. In general, matrix completion algorithms work well for low rank matrices. Such matrices find many applications in recommender systems and social network analysis. On the other hand, biological networks often yield high rank matrices. For example, the adjacency matrix representing interactions between transcription factors and target genes in the cell is a highly sparse matrix, in which most entries correspond to absent interactions and only a few entries correspond to present interactions. This sparse matrix is a high rank or even full rank matrix. Matrix completion …

Rational Drug Design Directed At Blocking The Initial Signaling Events In Lipopolysaccharide-Induced Sepsis., Christopher A. Tipton

Theses

Systemic Inflammatory Response Syndrome (SIRS) is classified as an immune system response to an infectious state. If left untreated, SIRS leads to sepsis, septic shock, end-organ dysfunction, and death. As a patient progresses through these stages, associations of acute respiratory distress, disseminated intravascular coagulation, and acute renal failure persist, resulting in millions of deaths annually. Lipopolysaccharide (LPS), a bacterial endotoxin, is released into the blood stream, triggering SIRS. LPS is found in the outer cell-wall of Gram-negative bacteria and is responsible for initiation of a devastating cytokine storm. One of the regions of LPS, lipid A, is a polyacylated glucosamine …

The Effect Of Watershed Runoff And Sediment Resuspension On Turbidity And Sediment Deposition In St. John, Us Virgin Islands: Implications For Watershed And Marine Development And Restoration In Bays With Coral Reefs, Stephen E. Campbell

Theses

In the US Virgin Islands (USVI), land-based (terrigenous) sedimentation has been identified as a major cause of coral stress. Development, such as the building of unpaved roads in steep coastal watersheds, has increased sediment yields and marine terrigenous sedimentation by up to an order of magnitude above background levels. When activated during storm events, ephemeral streams transport sediment from the watershed to coastal waters. Once deposited on the seafloor, resuspension of benthic sediments can further increase turbidity and deposition. However, isolating the relative contributions of runoff and resuspension to turbidity and deposition using conventional sediment trap monitoring has been challenging. …

Larval Rockfish Diversity Abundance Dynamics In Association With A Marine Protected Area In The Southern California Bight, Dustin Chen

Theses

Marine protected areas (MPAs) are areas aimed at protecting natural and cultural resources that are often proposed as a way to alleviate the effects of overfishing on populations of targeted species; these areas have varying degrees of fishing and recreational use restrictions. In order to assess MPA efficacy, it is important to determine the mechanisms by which the presence of MPAs affect reproductive output within and potentially even beyond their boundaries. I attempted to address this through studying the responses of rockfish (Sebastes spp.) larval abundances to the presence of the Cowcod Conservation Areas (CCAs) located within the Southern California …

Optimization Of A Combined Carbon/Oxygen And Neutron Porosity Oil Well Logging Tool, Entisar Ali Al Muraikhi

Theses

Well logging technique is used to determine the physical and chemical properties of borehole formation, by using neutron porosity oil well logging tools. The present study simplifies logging tool design in order to reduce the time spent on obtaining well logging. We have combined both carbon/oxygen (C/O) tool and thermal neutron porosity tool. This has been done by adding boron lining on the detectors in C/O tool, where the boron lining acts as a thermal neutron porosity tool while maintaining C/O functions simultaneously. The Monte Carlo N-Particle (MCNP) Transport Code, which was originally developed in Los Alamos National Laboratory, is …

A Parallelized Method For Solving Large Scale Integer Linear Optimization Problems Using Cut-And-Solve With Applications To Cgwas, John Brandenburg

Theses

The commercial solver CPLEX has been one of the top solvers of mixed-integer and purely integer linear problems for some time. Its method of solving, Branch-and-Cut, has been shown to be highly effective, but has its limits in terms of input sizes which are tractable, and cannot be effectively parallelized beyond a small number. Here we present a different method of solution, Cut-and-Solve, which utilizes the power of CPLEX to effectively parallelize any mixed-integer or integer linear problem. We have utilized Cut-and-Solve in a novel way to offer optimal solution guarantees more quickly. We will show comparisons of Cut-and-Solve to …

Network Exploration Of Correlated Multivariate Protein Data For Alzheimer's Disease Association, Matthew J. Lane

Theses

Alzheimer Disease (AD) is difficult to diagnose by using genetic testing or other traditional methods. Unlike diseases with simple genetic risk components, there exists no single marker determining as to whether someone will develop AD. Furthermore, AD is highly heterogeneous and different subgroups of individuals develop the disease due to differing factors. Traditional diagnostic methods using perceivable cognitive deficiencies are often too little too late due to the brain having suffered damage from decades of disease progression. In order to observe AD at early stages prior to the observation of cognitive deficiencies, biomarkers with greater accuracy are required. By using …

Mobile Big Data Analytics In Healthcare, Alramzana Nujum Navaz

Theses

Mobile and ubiquitous devices are everywhere around us generating considerable amount of data. The concept of mobile computing and analytics is expanding due to the fact that we are using mobile devices day in and out without even realizing it. These mobile devices use Wi-Fi, Bluetooth or mobile data to be intermittently connected to the world, generating, sending and receiving data on the move. Latest mobile applications incorporating graphics, video and audio are main causes of loading the mobile devices by consuming battery, memory and processing power. Mobile Big data analytics includes for instance, big health data, big location data, …

Unwrapping Mri Phase By Using Multi-Echo Technique, Shamma Ali Rashed Ali Al Hassani

Theses

Phase unwrapping is a classic signal processing problem and an unavoidable procedure that can be faced with in a variety of applications which are interested in the phase, such as synthetic aperture radar (SAR), field mapping in magnetic resonance imaging (MRI), wavefront distortion measurement of adaptive optics, interferometry, and surface shape measurement. Although phase unwrapping is one of the most challenging tasks in signal processing because of the presence of residues, noise in the data, discontinuities or other phase particularities, there are many successful phase unwrapping techniques and algorithms that have been developed in the last decades. In this thesis, …

Modeling The Mitigation Of Seawater Intrusion By Pumping Brackish Water From The Coastal Aquifer Of Wadi Ham, Uae, Modou A Sowe

Theses

The control and management of seawater intrusion in coastal aquifers is a major challenge in the field of water resources management. Seawater intrusion is a major problem in the coastal aquifer of Wadi Ham, United Arab Emirates caused by intensive groundwater abstraction from increased agricultural activities. This has caused the abonnement of salinized wells and ultimately affected farming activities and domestic water supply in the area. In this study, the 3D finite element groundwater flow and solute transport model, FEFLOW was used to simulate pumping of brackish water from the intrusion zone to control seawater intrusion in the aquifer. The …

Gallium-Doped Microporous Γ-Al2o3: The Effect Of Preparative Conditions And Composition On The Textural Properties And The Catalytic Activity In Methanol Conversion To Dimethyl Ether As A Clean Fuel Alternative, Rawad Maarouf Bou Jaber

Theses

Solid acid catalysts, such as γ-alumina, are important materials in different catalytic applications such as dehydration reactions of alcohols. Methanol is one of the most important intermediates that can be obtained from natural gas and can be further converted to other efficient fuels and chemicals. Dimethyl ether, which can be obtained from methanol, is being considered as a promising future fuel besides being the building block for several industrially important chemicals. Although γ-alumina has shown significant activity for the dehydration of methanol to dimethyl ether, improving the conversion and the selectivity at relatively low temperatures is still a major concern. …

Effects Of Environmental Diesel Exhaust Particles On Gastric Stem Cells, Heba Ahmed Mazen Al Sadik

Theses

I would like to express my special thanks to the General Secretariat of the Executive Council of Abu Dhabi Emirate and Abu Dhabi National Oil Company (ADNOC) for their input and support. Last, but certainly not least, these acknowledgments would be incomplete without expressing my deepest appreciation to my family. Special acknowledgment of this achievement goes to my parents, who not only showed me unconditional love, acceptance, and respect for the person that I am throughout my life, they also showed me the strength of character which has brought me to where I am today. To my wife, for her …

Microbial Degradation Of Various Organic Pollutants Using Bacteria Isolated From Petroleum Sludge, Manal Ali Hassan Saeed Alhefeiti

Theses

Intensification of agriculture and manufacturing industries has resulted in increased release of a wide range of xenobiotic compounds to the environment. The extensive discharge of hazardous waste in industrial wastewater and the recalcitrant nature of some of these organic pollutants have fueled a strong interest in exploring efficient and environmentally friendly approaches for wastewater remediation. Bioremediation approaches can provide efficient, inexpensive and environmentally safe cleanup tools. In the present study, our main objective was to isolate novel bacterial strains from UAE petroleum sludge and to examine their abilities to degrade various aromatic pollutants, including azo dyes and emerging pollutants. We …

Inkjet Printing Polymerized Pcda As A Means Of Serialization, Constantino Stavrou

Theses

Polymerized PCDA, otherwise known as pentacosadiynoic acid, due to its color changing response to high temperatures, has been used as a means of indicating whether the material has been exposed to high temperatures. Quick-Response codes or Q-R codes have been used as means of serialization due to their two-dimensional design, allowing for the embedding of larger amounts of information than their one-dimensional barcode predecessors.

Combining the colorimetric response of PCDA polymer with the information coding powers of Q-R codes, an improved version of the Q-R Code is made, which was used not only for serialization purposes, but as a means …

An Application Of Time Series Methods To Investigate Eu Dairy Commodity Price Dynamics, Dennis Bergmann

Theses

Fundamental changes to the common agricultural policy (CAP) have led to greater market orientation which in turn has resulted in significantly changed price dynamics of EU dairy prices. These changed dynamics include sharply increased price variability of EU farm gate milk prices as well EU dairy commodity prices such as butter and Skimmed Milk Powder (SMP). In addition it was expected that EU dairy prices will align to Word dairy prices. This alignment of prices would also see an alignment of volatility levels which were significantly higher for World dairy prices than EU dairy prices. The aim of this thesis …

Novel Neuroevolution Techniques For The Life Science Domain, Timothy Manning

Theses

The life science domain is a high value research area, both in terms of the benefits in increased knowledge and in societal impact. Much of the research funding has focused on wet lab based approaches to increase visibility into biological processes and producing maximal relevant information on which to make decisions. Given the complexity of biological functions, in many cases this has led to an information overload. Researchers are now able to routinely generate and access petabytes of data as a result of high throughput experiments, and this capability is growing. This data can be difficult to interpret and intractable …

Semiconductor Materials And Devices For 2 Micron Generation, Dzianis Saladukha

Theses

In the last century, semiconductor research has led to significant changes in the fields of communication, medicine, the environment, and many others. Semiconductor devices provide a relatively simple and effective way to convert electrical energy to light and vice versa. Devices based on semiconductor materials of various kinds provide interaction of an electromagnetic signal in the range of wavelengths with a medium. Examples of such devices are LED lamps, photovoltaic cells, thermometers, gas sensors, cameras, and many others. The study of various semiconductors broadens the range of application of photonics. This work is based on the study of materials which …

Intelligent Profiling Of Blood Donors In Ireland, Joanna Kossakowska

Theses

The demand for blood products in Ireland is constantly rising due to population growth and population ageing. It is believed that within the next decade these two factors will present challenges to blood donor recruitment and the availability of blood supplies. Improving the retention of blood donors will have a positive impact on the availability of blood products. Identification of suitable donors with the potential for long-term donating can potentially enhance the predictability of blood supply levels.

This research proposes that the patterns of blood donation behaviours of donors can be isolated from blood donor databases held by blood collecting …

Sedimentation Dynamics Of The Cagayan De Oro River Catchment And The Implications For Its Coastal Marine Environments, Mars P. Tan

Theses

Declines in coastal environment condition can often be attributed to land-based activities in the uplands. This may be the case in some parts of Macajalar Bay, where river plume is observed almost daily. This present study aims to demonstrate the erosion-sedimentation process along the Cagayan de Oro River Catchment to its river mouth, and its implication for the marine coastal habitats. Highlighted in the study are the various natural factors that have influenced the erosion-sedimentation process: its volume; direction; and effects on the coastal habitats.

In the uplands, to account for the influence of catchment spatial heterogeneity and local rainfall …

Development Of A Dynamic Cfd Model For Offshore Oscillating Water Columns With Non-Linear Interactions, Ken O'Connell

Theses

This thesis focuses on the development of a state of the art modelling technique for offshore Oscillating Water Column (OWC) type Wave Energy Converters (WEC) using Computational Fluid Dynamics (CFD). Current literature indicates a limited amount of work has been completed on studying these devices containing non-linear time dependent flow phenomenon. Initially, a 2D Numerical Wave Tank (NWT) is studied to reduce discretisation error in order to reproduce accurately propagating waves. Further development into a 3D domain permits the geometrical requirements of an OWC type spar buoy to be included.

In parallel, a single Degree of Freedom (DOF) model is …