1,147 Works

Industrial Computed Tomography using Proximal Algorithm

Guangming Zang
In this thesis, we present ProxiSART, a flexible proximal framework for robust 3D cone beam tomographic reconstruction based on the Simultaneous Algebraic Reconstruction Technique (SART). We derive the proximal operator for the SART algorithm and use it for minimizing the data term in a proximal algorithm. We show the flexibility of the framework by plugging in different powerful regularizers, and show its robustness in achieving better reconstruction results in the presence of noise and using...

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...

Towards an Efficient Artificial Neural Network Pruning and Feature Ranking Tool

Mona AlShahrani
Artificial Neural Networks (ANNs) are known to be among the most effective and expressive machine learning models. Their impressive abilities to learn have been reflected in many broad application domains such as image recognition, medical diagnosis, online banking, robotics, dynamic systems, and many others. ANNs with multiple layers of complex non-linear transformations (a.k.a Deep ANNs) have shown recently successful results in the area of computer vision and speech recognition. ANNs are parametric models that approximate...

Nonlinear Dynamics of Memristor Based 2nd and 3rd Order Oscillators

Abdul Hafiz Talukdar
Exceptional behaviours of Memristor are illustrated in Memristor based second order (Wien oscillator) and third order (phase shift oscillator) oscillator systems in this Thesis. Conventional concepts about sustained oscillation have been argued by demonstrating the possibility of sustained oscillation with oscillating resistance and dynamic poles. Mathematical models are also proposed for analysis and simulations have been presented to support the surprising characteristics of the Memristor based oscillator systems. This thesis also describes a comparative study...

Effect of Dimethyl Ether Mixing on Soot Size Distribution in Premixed Ethylene Flame

Zepeng Li
As a byproduct of incomplete combustion, soot attracts increasing attentions as extensive researches exploring serious health and environmental effects from soot particles. Soot emission reduction requires a comprehensive understanding of the mechanism for polycyclic aromatic hydrocarbons and of soot formation and aging processes. Therefore, advanced experimental techniques and numerical simulations have been conducted to investigate this procedure. In order to investigate the effects of dimethyl ether (DME) mixing on soot particle size distribution functions (PSDFs),...

An Underwater Superoleophobic Sepiolite Fibrous Membrane (SFM) for Oil­-in­-water Emulsion Separation

Pinjiang Yao
Separating oil/water emulsions is significant for the ecosystem and the petroleum and processing industry. To this end, we prepared an underwater superoleophobic membrane inspired by unique wettability of the fish scales. This membrane was fabricated by a facile vacuum filtration process of sepiolite nanofibers and chitosan, and after the cross-linking via glutaraldehyde, a self-standing membrane was obtained. The as-prepared membrane exhibited excellent capability of separating both the surfactant-free and surfactant-stabilized oil-in-water emulsions with high efficiency....

Using physicochemical and compositional characteristics of DNA sequence for prediction of genomic signals

Pierre Abraham Mulamba
The challenge in finding genes in eukaryotic organisms using computational methods is an ongoing problem in the biology. Based on various genomic signals found in eukaryotic genomes, this problem can be divided into many different sub­-problems such as identification of transcription start sites, translation initiation sites, splice sites, poly (A) signals, etc. Each sub-­problem deals with a particular type of genomic signals and various computational methods are used to solve each sub-­problem. Aggregating information from...

Transcriptional Profiling of Chromera velia Under Diverse Environmental Conditions

Annageldi Tayyrov
Since its description in 2008, Chromera velia has drawn profound interest as the closest free-­-living photosynthetic relative of apicomplexan parasites that are significant pathogens, causing enormous health and economic problems. There-­- fore, this newly described species holds a great potential to understand evolu-­- tionary basis of how photosynthetic algae evolved into the fully pathogenic Apicomplexa and how their common ancestors may have lived before they evolved into obligate parasites. Hence, the aim of this work...

Cytotoxic Effects of Nickel Nanowires in Human Fibroblasts

Laura P. Felix Servin
There is an increasing interest for the use of nanostructures as potential tools in areas that include biology and medicine, for applications spanning from cell separation to treatments of diseases. Magnetic nanoparticles (MNPs) have been the most widely studied and utilized nanostructures in biomedical applications. Despite their popularity, the regular shape of MNPs limits their potential for certain applications. Studies have shown that magnetic nanowires (MNWs), due to their high-­-aspect ratio and specific magnetic properties,...

Liquid Marbles

Kareem Khalil
Granulation, the process of formation of granules from a combination of base powders and binder liquids, has been a subject of research for almost 50 years, studied extensively for its vast applications, primarily to the pharmaceutical industry sector. The principal aim of granulation is to form granules comprised of the active pharmaceutical ingredients (API’s), which have more desirable handling and flowability properties than raw powders. It is also essential to ensure an even distribution of...

Growth Curve Analysis and Change-Points Detection in Extremes

Rui Meng
The thesis consists of two coherent projects. The first project presents the results of evaluating salinity tolerance in barley using growth curve analysis where different growth trajectories are observed within barley families. The study of salinity tolerance in plants is crucial to understanding plant growth and productivity. Because fully-automated smarthouses with conveyor systems allow non-destructive and high-throughput phenotyping of large number of plants, it is now possible to apply advanced statistical tools to analyze daily...

Separation, Characterization and Fouling Potential of Sludge Waters from Different Biological Wastewater Treatment Processes

Jinkai Xue
The major limitation, which hinders the wider application of membrane technology and increases the operating costs of membranes involved in wastewater treatment plants, is membrane fouling induced by organic matter. Extracellular polymeric products (EPS) and soluble microbial products (SMP) are the two most mentioned major foulants in publications, for which the debate on precise definitions seems to be endless. Therefore, a concept of sludge water, which conceptually covers both EPS and SMP, has been developed...

Synthesis, Characterization and Application of Poly (Styrene-4- Vinyl Pyridine) Membranes Assembled With Single-Wall Carbon Nanotubes

Haoze He
Poly(styrene-4-vinylpyridine) (PS-P4VP) isoporous membranes were prepared and their properties were evaluated in this research. The solution was prepared by dissolving PS-P4VP polymer with necessary additives into a 1:1:1 1,4-dioxane – N,N-dimethyl formamide – tetrahydrofuran (DOX-DMF-THF, DDT) solvent. Then 0.5-1.0 mL of the primary solution was cast onto the non-woven substrate membrane on a glass slide, evaporated for 15-20 sec and immersed into de-ionized water for more than 30 min for the solidification of isoporous structure...

Study of Monte Carlo Simulation Method for Methane Phase Diagram Prediction using Two Different Potential Models

Ahmad Salim Kadoura
Lennard-Jones (L-J) and Buckingham exponential-6 (exp-6) potential models were used to produce isotherms for methane at temperatures below and above critical one. Molecular simulation approach, particularly Monte Carlo simulations, were employed to create these isotherms working with both canonical and Gibbs ensembles. Experiments in canonical ensemble with each model were conducted to estimate pressures at a range of temperatures above methane critical temperature. Results were collected and compared to experimental data existing in literature; both...

Antimicrobial and Cytotoxic Activities of Extracts from Laurus nobilis Leaves

Shaza Felemban
The cytotoxic activity and antimicrobial properties of crude extracts from Laurus nobilis were investigated. With the use of the organic solvents, methanol and ethanol, crude extracts were obtained. To determine the availability of active bio-compounds, an analysis using liquid chromatography was conducted. The crude extract was also tested for antimicrobial activity. The disc diffusion method was used against the bacterium Escherichia coli. The results showed a weak antimicrobial activity against E. coli. For cytotoxicity testing,...

Carbon Sequestration in Saline Aquifers: Modeling Diffusive and Convective Transport Of a Carbon-­Dioxide Cap

Rebecca Allen
An increase in the earth’s surface temperature has been directly linked to the rise of carbon dioxide (CO2) levels In the atmosphere and an enhanced greenhouse effect. CO2 sequestration is one of the proposed mitigation Strategies in the effort to reduce atmospheric CO2 concentrations. Globally speaking, saline aquifers provide an adequate storage capacity for the world’s carbon emissions, and CO2 sequestration projects are currently underway in countries such as Norway, Germany, Japan, USA, and others....

The Mechanism of the Silencing of a Transgene, NCED3-LUC, in Arabidopsis Thaliana

Junsong Zhao
The Arabidopsis thaliana NCED3-LUC transgenic line was constructed by several groups to study the regulatory network of the NCED3 gene, the protein of which catalyzes the rate-limiting step of ABA biosynthesis under drought. The transgenic luciferase gene is expressed when the plants encounter drought stress. Intriguingly, this transgenic luciferase gene is silenced after propagation for several generations. To determine the mechanism of this gene silencing, we used a forward genetics approach. The seeds of NCED3-LUC...

Molecular Characterization of the Plant Growth Promoting Bacterium Enterobacter sp. SA187 upon Contact with Arabidopsis thaliana

Wiam Alsharif
Salt stress is a severe environmental challenge in agriculture, limiting the quality and productivity of the crops around the globe. Plant growth promoting rhizobacteria (PGPR) is proposed as a friendly solution to overcome those challenges. The desert plant endophytic bacterium, Enterobacter sp. SA187 has shown plant growth promotion and salt stress tolerance beneficial effect on the model plant Arabidopsis thaliana in vitro as well as under the field conditions on different crops. SA187 has a...

Towards Optimal Buffer Size in Wi-Fi Networks

Ahmad Showail
Buffer sizing is an important network configuration parameter that impacts the quality of data traffic. Falling memory cost and the fallacy that ‘more is better’ lead to over provisioning network devices with large buffers. Over-buffering or the so called ‘bufferbloat’ phenomenon creates excessive end-to-end delay in today’s networks. On the other hand, under-buffering results in frequent packet loss and subsequent under-utilization of network resources. The buffer sizing problem has been studied extensively for wired networks....

The Effect of Nitrogen Surface Ligands on Propane Metathesis: Design and Characterizations of N-modified SBA15-Supported Schrock-type Tungsten Alkylidyne

Ahmed A. Eid
Catalysis, which is primarily a molecular phenomenon, is an important field of chemistry because it requires the chemical conversion of molecules into other molecules. It also has an effect on many fields, including, but not limited to, industry, environment and life Science[1]. Surface Organometallic Chemistry is an effective methodology for Catalysis as it imports the concept and mechanism of organometallic chemistry, to surface science and heterogeneous catalysis. So, it bridges the gap between homogenous and...

Testing the Feasibility of Using PERM to Apply Scattering-Angle Filtering in the Image-Domain for FWI Applications

Hani Ataiq Alzahrani
ABSTRACT Testing the Feasibility of Using PERM to Apply Scattering-Angle Filtering in the Image-Domain for FWI Applications Hani Ataiq Alzahrani Full Waveform Inversion (FWI) is a non-linear optimization problem aimed to estimating subsurface parameters by minimizing the mis t between modeled and recorded seismic data using gradient descent methods, which are the only practical choice because of the size of the problem. Due to the high non-linearity of the problem, gradient methods will converge to...

P-type Oxide Semiconductors for Transparent & Energy Efficient Electronics

Zhenwei Wang
Emerging transparent semiconducting oxide (TSO) materials have achieved their initial commercial success in the display industry. Due to the advanced electrical performance, TSOs have been adopted either to improve the performance of traditional displays or to demonstrate the novel transparent and flexible displays. However, due to the lack of feasible p-type TSOs, the applications of TSOs is limited to unipolar (n-type TSOs) based devices. Compared with the prosperous n-type TSOs, the performance of p-type counterparts...

First assessment of viral diversity across corals from the central Red Sea suggests abundant association with Baculoviridae

Jin Ye
Coral reefs are among the most diverse marine ecosystems, but they are threatened by climate change. The foundation of reef ecosystems is the coral holobiont or metaorganism that consists of the coral animal host, photosynthetic microalgae, bacteria, and viruses (among other organisms). While microalgae provide the energy for corals to build the massive three-dimensional skeletons, bacteria support functions related to metabolism, immunity, and environmental adaptation. Conversely, the function of viruses is less well understood. Although...

Optimization of an Efficient and Sustainable Sonogashira Cross-Coupling Protocol

Philipp E. Walter
Cross coupling reactions are a well-established tool in modern organic synthesis and play a crucial role in the synthesis of a high number of organic compounds. Their importance is highlighted by the Nobel Prize in chemistry to Suzuki, Heck and Negishi in 2010. The increasing importance of sustainability requirements in chemical production has furthermore promoted the development of cross-coupling protocols that comply with the principles of “Green Chemistry”1. The Sonogashira reaction is today the most...

Mesoporous Carbon Produced from Tri-constituent Mesoporous Carbon-silica Composite for Water Purification

Yanjie Yu
Highly ordered mesoporous carbon-silica nanocomposites with interpenetrating carbon and silica networks were synthesized by the evaporation-induced tri-constituent co- assembly approach. The removal of silica by concentrated NaOH solution produced mesoporous carbons, which contained not only the primary large pores, but also the secondary mesopores in the carbon walls. The thus synthesized mesoporous carbon was further activated by using ZnCl2. The activated mesoporous carbon showed an improved surface area and pore volume. The synthesized mesoporous carbon...

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