225 Works
Contributions to the semi-classical signal analysis method: The arterial stiffness assessment case study
Evangelos Piliouras
Semi-classical signal analysis (SCSA) is a signal representation framework based on quantum mechanics principles and the inverse scattering transform. The signal of interest is decom- posed in a linear combination of the Schrodinger operator squared eigenfunctions, influenced by the semi-classical parameter. The framework has been utilized in several applications, in virtue of the adaptivity and localization of its components. In this thesis, we expand two direc- tions. From the theoretical perspective, up to date, the...
Rejection of Organic Micropollutants by Nanofiltration and Reverse Osmosis Membranes
Emmanuel Alonso
Abstract: The worldwide consumption of pharmaceuticals and personal care products for healthcare purposes has resulted in the occurrence of organic micropollutants (OMPs) in freshwater and wastewater resources. These pollutants are not entirely removed by conventional water and wastewater treatment plants, leading to potential human and animal health problems. Membranes are a promising technology capable of solving this problem. This study evaluated the ability of high-pressure driven membranes such as nanofiltration (NF) and reverse osmosis (RO)...
Percolation Theory-Analysis of Malware Epidemics in Large-Scale Wireless Networks
Ainur Zhaikhan
The foreseen massive deployment of the internet of things (IoT) is expected to suffer from high security risks. This mainly results from the difficulty to monitor and cure the IoT devices in such large-scale deployment. In this thesis, we propose a spatial random deployment of special nodes (firewalls) which can detect and cure infected nodes within certain radius. An important concern is to add sufficient number of firewalls to make an epidemics finite and, hence,...
Analyzing Germline-Specific Expression in Caenorhabditis elegans
Samar Alkoblan
Maintaining cells in an undifferentiated totipotent state is essential for initiating developmental programs that lead to a fully formed organism in each generation and for maintaining immortal germ cells across generations. Caenorhabditis elegans is a powerful genetic model organism to study early germ cell development due to the animal’s transparency and the ability to screen for mutant phenotypes. However, our ability to use standard techniques to study gene expression using fluorescent reporter genes has been...
Machine Learning to Predict Entropy and Heat Capacity of Hydrocarbons
Mohammed Aldosari
Chemical substances are essential to all aspects of human life, and understanding their properties is essential for effective application. The properties of chemical species are usually measured by experimentation or computational calculation using theoretical methods. In this work, machine learning models (ML) for predicting entropy, S, and heat capacity, cp, were developed for alkanes, alkenes, and alkynes at 298.15 K. The data for entropy and heat capacity were collected from various sources. Commercial software (alvaDesc)...
Contact Angle Hysteresis: Implications for Fluid Flow
Cristhian F. Andrade
Contact angle behavior controls the spreading, sticking, or movement of fluid droplets on top of solid substrates, and the immiscible displacement of mixed fluids in porous media. Therefore, it influences applications such as oil recovery, CO2 geological storage, water transport in unsaturated soils, and DNAPL soil remediation techniques. The attraction forces and geometrical-molecular arrangement at the atomic scale define the strength of the interfacial tension that changes in response to changes in temperature, pressure, or...
Dynamics of heterotrophic bacterioplankton in costal ecosystems of the central Red Sea
Luis Silva
Heterotrophic bacterioplankton dynamics have seldom been assessed in the Red Sea, an exceptionally warm oligotrophic basin, which could be used as a model for the future ocean. To understand the function of heterotrophic bacteria in biogeochemical cycles and the flows of matter and energy to higher trophic levels, it is peremptory to understand how bacterial growth is controlled. Bottom-up (resources availability), top-down (mortality by predators and viruses) and temperature are the main hypotheses of control...
The Rootstock-Scion Combination Drives Microorganisms’ Selection and Recruitment in Grapevine Rhizosphere
Hend Alturkey
In the last decade, several studies demonstrated that plants have developed a tight partnership with the edaphic microbial communities, mainly bacteria, fungi, and archaea. Such microbiome accomplishes essential functions and ecological services complementary to the functions encoded by the host plant, conferring adaptive advantages to the plant, particularly during stressful conditions. The interaction between microbial communities and their host plants in the natural ecosystem are complex and the mechanisms regulating these mutualistic associations are not...
A Comparative DNA Binding Study of the Human MAPK ERK2 and the Plant MAPK MPK4
Siba I. Alharbi
Mitogen-activated protein kinases (MAPKs) are an important subfamily of protein kinases that are well conserved in all eukaryotes. MAPKs are the final component of a three-tiered signaling module that regulates the activation of various essential cellular responses. They activate most of their substrates through catalyzing their phosphorylation. However, emerging evidence reveals that some MAPKs also possess non-catalytic functions. In particular, the human MAPK ERK2 can bind to DNA directly and mediate gene expression. The mechanism...
Acoustic Scattering from 3D Rigid Objects
Noha Al-Harthi, Rabab Alomairy, Kadir Akbudak, Rui Chen, Hatem Ltaief, Hakan Bagci & David E. Keyes
The dataset contains meshes of a unit sphere and a simplified submarine model generated using I-DEAS software. There are three important parameters: edge length, order of curvilinear elements (both are inputs to I-DEAS), and number of elements. Element order 2 for all meshes in the dataset.
Machine Learning Models for Biomedical Ontology Integration and Analysis
Fatima Z. Smaili
Biological knowledge is widely represented in the form of ontologies and ontology-based annotations. Biomedical ontologies describe known phenomena in biology using formal axioms, and the annotations associate an entity (e.g. genes, diseases, chemicals, etc.) with a set of biological concepts. In addition to formally structured axioms, ontologies contain meta-data in the form of annotation properties expressed mostly in natural language which provide valuable pieces of information that characterize ontology concepts. The structure and information contained...
The Umklapp Scattering and Spin Mixing Conductance in Collinear Antiferromagnets
Nisreen Alshehri
Antiferromagnetic spintronics is a new promising field in applied magnetism. Antiferromagnetic materials display a staggered arrangement of magnetic moments so that they exhibit no overall magnetization while possessing a local magnetic order. Unlike ferromagnets that possess a homogeneous magnetic order, the spin-dependent phenomena occur locally upon the interaction between the itinerant electron and the localized magnetic moments. In fact, unique spin transport properties such as anisotropic magnetoresistance, anomalous Hall effect, magnetooptical Kerr effect, spin transfer...
Photophysical Processes in Lead Halide Perovskite Solar Cells Revealed by Ultrafast Spectroscopy
Esma Ugur
Metal halide perovskites have emerged as photoactive materials in solution-processed devices thanks to their unique properties such as high absorption coefficient, sharp absorption edge, long carrier diffusion lengths, and tunable bandgap, together with ease of fabrication. The single-junction perovskite solar cells have reached power conversion efficiencies of more than 25%. Although the efficiency of perovskite devices has increased tremendously in a very short time, the efficiency is still limited by carrier recombination at defects and...
Halide Perovskites: Materials Properties and Emerging Applications
Mohammed Haque
Semiconducting materials have emerged as the cornerstone of modern electronics owing to their extensive device applications. There is a continuous quest to find cost-effective and low-temperature compatible materials for future electronics. The recent reemergence of solution processable halide perovskites have taken the optoelectronics research to new paradigms. Apart from photovoltaics, the versatile characteristics of halide perovskites have resulted in a multitude of applications. This dissertation focuses on various properties and emerging applications particularly, photodetection and...
Learning from Scholarly Attributed Graphs for Scientific Discovery
Uchenna Thankgod Akujuobi
Research and experimentation in various scientific fields are based on the knowledge and ideas from scholarly literature. The advancement of research and development has, thus, strengthened the importance of literary analysis and understanding. However, in recent years, researchers have been facing massive scholarly documents published at an exponentially increasing rate. Analyzing this vast number of publications is far beyond the capability of individual researchers. This dissertation is motivated by the need for large scale analyses...
Micro-electromechanical Resonator-based Logic and Interface Circuits for Low Power Applications
Sally Ahmed
The notion of mechanical computation has been revived in the past few years, with the advances of nanofabrication techniques. Although electromechanical devices are inherently slow, they offer zero or very low off-state current, which reduces the overall power consumption compared to the fast complementary-metal-oxide-semiconductor (CMOS) counterparts. This energy efficiency feature is the most crucial requirement for most of the stand-alone battery-operated gadgets, biomedical devices, and the internet of things (IoT) applications, which do not require...
Mesoscale Eddy Dynamics and Scale in the Red Sea
Michael F Campbell
Recent efforts in understanding the variability inherent in coastal and offshore waters have highlighted the need for higher resolution sampling at finer spatial and temporal resolutions. Gliders are increasingly used in these transitional waters due to their ability to provide these finer resolution data sets in areas where satellite coverage may be poor, ship-based surveys may be impractical, and important processes may occur below the surface. Since no single instrument platform provides coverage across all...
The Harrat volcanic Fields on the Arabian Peninsula: their geologic setting, petrology, and suitability for carbon disposal
Miliausha V. Petrova
This thesis evaluates the suitability of the Late Miocene-Recent basalts on the Harrat volcanic elds of Saudi Arabia for the disposal of CO2 emitted from industrial sources. For this evaluation, topography, geological setting, hydrology, and petrology of the Harrat basalts are the most important parameters. The basalts must have su cient thickness of at least 500 m of which at least 400 m must be saturated with groundwater in order to completely dissolve CO2 at...
Leveraging Graph Convolutional Networks for Point Cloud Upsampling
Guocheng Qian
Due to hardware limitations, 3D sensors like LiDAR often produce sparse and noisy point clouds. Point cloud upsampling is the task of converting such point clouds into dense and clean ones. This thesis tackles the problem of point cloud upsampling using deep neural networks. The effectiveness of a point cloud upsampling neural network heavily relies on the upsampling module and the feature extractor used therein. In this thesis, I propose a novel point upsampling module,...
A Novel HVDC Architecture for Offshore Wind Farm Applications
Otávio José Dezem Bertozzi Junior
The increasing global participation of wind power in the overall generation ca- pacity makes it one of the most promising renewable resources. Advances in power electronics have enabled this market growth and penetration. Through a literature review, this work explores the challenges and opportunities presented by offshore wind farms, as well as the different solutions proposed concerning power electron- ics converters, collection and transmission schemes, as well as control and protection techniques. A novel power...
Cancer Therapy based on Core-Shell Iron-Iron Oxide Nanowires
Aldo Martinez Banderas
Nanomaterials have been widely investigated for improving the treatment of diseases acting as vectors for diverse therapies and as diagnostic tools. Iron-based nanowires possess promising potential for biomedical applications due to their outstanding properties. The combination of different therapeutic and diagnostic strategies into one single platform is an approach for more efficient and safer treatments. In this thesis, I investigate the application of iron-iron oxide core-shell nanowires as therapeutic agents for cancer treatment. In particular,...
Enhancing the bonding of CFRP adhesive joints through laser-based surface preparation strategies
Ran Tao
Nowadays, Carbon Fiber-Reinforced Polymers (CFRPs) have been widely applied in the aerospace and automotive industries. Secondary adhesive bonding, instead of using rivets or bolts in conventional mechanical fastenings, is promising in joining CFRPs because it is simple and applicable for cured parts, widely applied for repairing structures, and of light weight. However, the mechanical performance of secondary bonding is very sensitive to the treatment of CFRP parts. Besides, another concern arises from the fact that...
Sustainability Evaluation of Hybrid Desalination Systems: Multi Effect Distillation – Adsorption (MED-AD) and Forward Osmosis – Membrane Distillation (FO-MD)
Hyuk Soo Son
Water is life for all living organisms on earth, and all human beings need water for every socio-economic activity in their daily lives. However, constant challenges are faced in securing quality water resources due to environmental pollution, a growing demand, and climate changes. To overcome imminent worldwide challenges on water resources, desalination of seawater and saline wastewater became inevitable, and significant efforts have been deployed by the desalination research community to advance the technology. However,...
Fundamental Molecular Communication Modelling
Nadezhda Briantceva
As traditional communication technology we use in our day-to-day life reaches its limitations, the international community searches for new methods to communicate information. One such novel approach is the so-called molecular communication system. During the last few decades, molecular communication systems become more and more popular. The main difference between traditional communication and molecular communication systems is that in the latter, information transfer occurs through chemical means, most often between microorganisms. This process already happens...
An experimental study of spray collapse under ash boiling conditions
Jianguo Du
Gasoline and gasoline-like fuels (naphtha) have high volatility, which results in flash boiling spray in gasoline engines when operated at throttling or low load conditions. Flash boiling can achieve better atomization, thus benefit fuel evaporation and fuel-air mixing. However, when flash boiling occurs, spray morphology, and fuel distribution are dramatically varied from the injectors' intentional design. This difference will affect the performance of combustion and emissions. Thus it is essential to investigate the spray collapse...