1,224 Works


Saad Ilyas
This dissertation presents the modeling, design, fabrication, and experimental testing of a polyimide based micro mirror for applications in MEMS logic devices based on its static behavior and in MEMS resonators using mixed frequency excitation. First, a universal MEMS logic device that can perform all the logic operations, such as INVERTER, AND, NAND, NOR, and OR gates using one physical structure, within an operating range of 0-10 volts. It can also perform XOR and XNOR...

Hydrodynamic Drag on Streamlined Projectiles and Cavities

Aditya Jetly
The air cavity formation resulting from the water-entry of solid objects has been the subject of extensive research due to its application in various fields such as biology, marine vehicles, sports and oil and gas industries. Recently we demonstrated that at certain conditions following the closing of the air cavity formed by the initial impact of a superhydrophobic sphere on a free water surface a stable streamlined shape air cavity can remain attached to the...

Massively Parallel Dimension Independent Adaptive Metropolis

Yuxin Chen
This work considers black-box Bayesian inference over high-dimensional parameter spaces. The well-known and widely respected adaptive Metropolis (AM) algorithm is extended herein to asymptotically scale uniformly with respect to the underlying parameter dimension, by respecting the variance, for Gaussian targets. The result- ing algorithm, referred to as the dimension-independent adaptive Metropolis (DIAM) algorithm, also shows improved performance with respect to adaptive Metropolis on non-Gaussian targets. This algorithm is further improved, and the possibility of probing...

Study of Diurnal Cycle Variability of Planetary Boundary Layer Characteristics over the Red Sea and Arabian Peninsula

Weigang Li
This work is aimed at investigating diurnal cycle variability of the planetary boundary layer characteristics over the Arabian Peninsula and the Red Sea region. To fulfill this goal the downscaling simulations are performed using Weather Research and Forecasting (WRF) model. We analyze planetary boundary layer height, latent and sensible heat fluxes, and surface air temperature. The model results are compared with observations in different areas, for different seasons, and for different model resolutions. The model...

How Corals Got Bones - Comparative Genomics Reveals the Evolution of Coral Calcification

Xin Wang
Scleractinian corals represent the foundation species of one of the most diverse and productive ecosystem on earth, coral reefs. Corals not only constitute the trophic basis of these ecosystems, but also provide essential habitats and shelter for a wide variety of marine species, many of which are commercially relevant. They also provide other important ecosystem services such as food provision, shoreline protection and opportunities for ecotourism. Despite the ecological importance of corals, very little is...

Self-assembled Block Copolymer Membranes with Bioinspired Artificial Channels

Burhannudin Sutisna
Nature is an excellent design that inspires scientists to develop smart systems. In the realm of separation technology, biological membranes have been an ideal model for synthetic membranes due to their ultrahigh permeability, sharp selectivity, and stimuliresponse. In this research, fabrications of bioinspired membranes from block copolymers were studied. Membranes with isoporous morphology were mainly prepared using selfassembly and non-solvent induced phase separation (SNIPS). An effective method that can dramatically shorten the path for designing...

Synthesis, Characterization, and Application of Superhydrophobic Sands in Desert Agriculture

Joel W. Reihmer
A sustainable supply of fresh water for the human population is a global concern. Intriguingly, about 70% of the total fresh water consumed in the world annually is claimed by agriculture alone; this fraction is even higher in the Middle East and North Africa (MENA) region, where natural regeneration of groundwater is the slowest. Thus, there is a serious need for innovative materials and technologies to enhance the efficiency water usage in agriculture. To this...

Compressive Sensing for Feedback Reduction in Wireless Multiuser Networks

Khalil Elkhalil
User/relay selection is a simple technique that achieves spatial diversity in multiuser networks. However, for user/relay selection algorithms to make a selection decision, channel state information (CSI) from all cooperating users/relays is usually required at a central node. This requirement poses two important challenges. Firstly, CSI acquisition generates a great deal of feedback overhead (air-time) that could result in significant transmission delays. Secondly, the fed-back channel information is usually corrupted by additive noise. This could...

An Exact and Grid-free Numerical Scheme for the Hybrid Two Phase Traffic Flow Model Based on the Lighthill-Whitham-Richards Model with Bounded Acceleration

Shanwen Qiu
In this article, we propose a new grid-free and exact solution method for computing solutions associated with an hybrid traffic flow model based on the Lighthill- Whitham-Richards (LWR) partial differential equation. In this hybrid flow model, the vehicles satisfy the LWR equation whenever possible, and have a fixed acceleration otherwise. We first present a grid-free solution method for the LWR equation based on the minimization of component functions. We then show that this solution method...

Magnetic Nanowires as Materials for Cancer Cell Destruction

Maria F. Contreras
Current cancer therapies are highly cytotoxic and their delivery to exclusively the affected site is poorly controlled, resulting in unavoidable and often severe side effects. In an effort to overcome such issues, magnetic nanoparticles have been recently gaining relevance in the areas of biomedical applications and therapeutics, opening pathways to alternative methods. This led to the concept of magnetic particle hyperthermia in which magnetic nano beads are heated by a high power magnetic field. The...

Scalable Frequent Subgraph Mining

Ehab Abdelhamid
A graph is a data structure that contains a set of nodes and a set of edges connecting these nodes. Nodes represent objects while edges model relationships among these objects. Graphs are used in various domains due to their ability to model complex relations among several objects. Given an input graph, the Frequent Subgraph Mining (FSM) task finds all subgraphs with frequencies exceeding a given threshold. FSM is crucial for graph analysis, and it is...

Miniaturized and Ferrite Based Tunable Bandpass Filters in LCP and LTCC Technologies for SoP Applications

Eyad A. Arabi
Wireless systems with emerging applications are leaning towards small size, light-weight and low cost. Another trend for these wireless devices is that new applications and functionalities are being added without increasing the size of the device. To accomplish this, individual components must be miniaturized and the system should be designed to maximize the integration of the individual components. The high level of 3D integration feasible in system on package design (SoP) concept can fulfill the...

Analytic Treatment of Deep Neural Networks Under Additive Gaussian Noise

Modar Alfadly
Despite the impressive performance of deep neural networks (DNNs) on numerous vision tasks, they still exhibit yet-to-understand uncouth behaviours. One puzzling behaviour is the reaction of DNNs to various noise attacks, where it has been shown that there exist small adversarial noise that can result in a severe degradation in the performance of DNNs. To rigorously treat this, we derive exact analytic expressions for the first and second moments (mean and variance) of a small...

III-nitride Photonic Integrated Circuit: Multi-section GaN Laser Diodes for Smart Lighting and Visible Light Communication

Chao Shen
The past decade witnessed the rapid development of III-nitride light-emitting diodes (LEDs) and laser diodes (LDs), for smart lighting, visible-light communication (VLC), optical storage, and internet-of-things. Recent studies suggested that the GaN-based LDs, which is free from efficiency droop, outperform LEDs as a viable high-power light source. Conventionally, the InGaN-based LDs are grown on polar, c-plane GaN substrates. However, a relatively low differential gain limited the device performance due to a significant polarization field in...

Microbial Aggregate and Functional Community Distribution in a Sequencing Batch Reactor with Anammox Granules

Shan Sun
Anammox (anaerobic ammonium oxidation) process is a one-step conversion of ammonia into nitrogen gas with nitrite as an electron acceptor. It has been developed as a sustainable technology for ammonia removal from wastewater in the last decade. For wastewater treatment, anammox biomass was widely developed as microbial aggregate where the conditions for enrichment of anammox community must be delicately controlled and growth of other bacteria especially NOB should be suppressed to enhance nitrogen removal efficiency....

Concept of Compound Retention Time for Organic Micro Pollutants in Anaerobic Membrane Bioreactor with Nanofiltration

Jiangjiang Pan
Organic micropollutants (OMPs) have received more and more attention in recent years due to their potential harmful effects on public health and aquatic ecosystems, and eliminating OMPs in wastewater treatment systems is an important solution to control OMPs wastage. An innovative hybrid process, anaerobic membrane bioreactor with nanofiltration (AnMBR-NF), in which enhanced OMPs removal is possible based on the concept of compound retention time (CRT) through coupling anaerobic biodegradation and NF rejection, is proposed and...

Analysis and Modeling of Social In uence in High Performance Computing Workloads

Shuai Zheng
High Performance Computing (HPC) is becoming a common tool in many research areas. Social influence (e.g., project collaboration) among increasing users of HPC systems creates bursty behavior in underlying workloads. This bursty behavior is increasingly common with the advent of grid computing and cloud computing. Mining the user bursty behavior is important for HPC workloads prediction and scheduling, which has direct impact on overall HPC computing performance. A representative work in this area is the...

Preparation of Reduced Graphene Oxides as Electrode Materials for Supercapacitors

Yaocai Bai
Reduced graphene oxide as outstanding candidate electrode material for supercapacitor has been investigated. This thesis includes two topics. One is that three kinds of reduced graphene oxides were prepared by hydrothermal reduction under different pH conditions. The pH values were found to have great influence on the reduction of graphene oxides. Acidic and neutral media yielded reduced graphene oxides with more oxygen-functional groups, lower specific surface areas but broader pore size distributions than those in...

A Robust Vision-based Runway Detection and Tracking Algorithm for Automatic UAV Landing

Khaled F. Abu Jbara
This work presents a novel real-time algorithm for runway detection and tracking applied to the automatic takeoff and landing of Unmanned Aerial Vehicles (UAVs). The algorithm is based on a combination of segmentation based region competition and the minimization of a specific energy function to detect and identify the runway edges from streaming video data. The resulting video-based runway position estimates are updated using a Kalman Filter, which can integrate other sensory information such as...

Molecular Epidemiology of Viral Gastroenteritis in Hajj pilgrimage

Eriko Padron Regalado
Hajj is the annual gathering of Islam practitioners in Mecca, Saudi Arabia. During the event, gastrointestinal infections are usually experienced and outbreaks have always been a concern; nevertheless, a deep and integrative study of the etiological agents has never been carried out. Here, I describe for the first time the epidemiology of pathogenic enteric viruses during Hajj 2011, 2012 and 2013. The focus of this study was the common enteric viruses Astrovirus, Norovirus, Rotavirus and...

Stimuli-Responsive Materials for Controlled Release Applications

Song Li
The controlled release of therapeutics has been one of the major challenges for scientists and engineers during the past three decades. To address this outstanding problem, the design and fabrication of stimuli-responsive materials are pursued to guarantee the controlled release of cargo at a specific time and with an accurate amount. Upon applying different stimuli such as light, magnetic field, heat, pH change, enzymes or redox, functional materials change their physicochemical properties through physical transformation...

Nanoengineering of Ruthenium and Platinum-based Nanocatalysts by Continuous-Flow Chemistry for Renewable Energy Applications

Noktan Mohammed AlYami
This thesis presents an integrated study of nanocatalysts for heterogenous catalytic and electrochemical processes using pure ruthenium (Ru) with mixed-phase and platinum-based nanomaterials synthesized by continuous-flow chemistry. There are three major challenges to the application of nanomaterials in heterogenous catalytic reactions and electrocatalytic processes in acidic solution. These challenges are the following: (i) controlling the size, shape and crystallography of nanoparticles to give the best catalytic properties, (ii) scaling these nanoparticles up to a commercial...

Generation of Hybrid Peptide-Silver Nanoparticles for Antibacterial and Antifouling Applications

Kholoud Seferji
An alarming increase of antibiotic-resistant bacterial strains has made the demand for novel antibacterial agents, for example, more effective antibiotics, highly crucial. One of the oldest antimicrobial agents is elementary silver which has been used for thousands of years. Even in our days, elementary silver is used for medical purposes, such as for burns, wounds, and microbial infections. We have taken the effectiveness of elementary silver into consideration to generate novel antibacterial and antifouling agents....

Molecular Simulation towards Efficient and Representative Subsurface Reservoirs Modeling

Ahmad Salim Kadoura
This dissertation focuses on the application of Monte Carlo (MC) molecular simulation and Molecular Dynamics (MD) in modeling thermodynamics and flow of subsurface reservoir fluids. At first, MC molecular simulation is proposed as a promising method to replace correlations and equations of state in subsurface flow simulators. In order to accelerate MC simulations, a set of early rejection schemes (conservative, hybrid, and non-conservative) in addition to extrapolation methods through reweighting and reconstruction of pre-generated MC...

Stationary Mean-Field Games with Congestion

David Evangelista
Mean-field games (MFG) are models of large populations of rational agents who seek to optimize an objective function that takes into account their state variables and the distribution of the state variable of the remaining agents. MFG with congestion model problems where the agents’ motion is hampered in high-density regions. First, we study radial solutions for first- and second-order stationary MFG with congestion on Rd. The radial case, which is one of the simplest non...

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