240 Works

Performance Evolution of Organic Solar Cells Using Nonfullerene Fused-Ring Electron Acceptors

Xin Song
As one of the most promising solar cell technologies, organic solar cells have unique superiorities distinct from inorganic counterparts, such as semitransparency, flexibility and solution-processability, as well as tunable photophysical properties, which originate from the structural verstailities of organic semiconductors. A major breakthrough in OSCs was the exploration of novel non-fullerene electron acceptor (NFAs): In comparison with traditional fullerene derivative acceptors, NFA possesses several advantages, such as low synthesis cost, tunable absorption range and adjustable...

Enhanced Chemical Cleaning of Reverse Osmosis Membranes to Mitigate Biofouling

Huma Sanawar
The effectiveness of reverse osmosis (RO) membrane systems may be compromised due to fouling, of which biofouling (excessive growth of biomass) is the most troublesome. Effective control of biofouling is essential to improve membrane performance and reduce operating costs. The periodic application of chemical cleaning agents is possibly the most widely practiced method of biofouling control in RO membranes. This research investigated advanced chemical cleaning strategies for biofouling control. The first part of this study...


Itsikiantsoa Randrianantenaina
The demand for wireless communication is ceaselessly increasing in terms of the number of subscribers and services. Future generations of cellular networks are expected to allow not only humans but also machines to be immersively connected. However, the radio frequency spectrum is already fully allocated. Therefore, developing techniques to increase spectrum efficiency has become necessary. This dissertation analyzes two spectrum sharing techniques that enable efficient utilization of the available radio resources in cellular networks. The...

Development of Solution Processed Co-planar Nanogap Capacitors and Diodes for RF Applications Enabled Via Adhesion Lithography

Zainab Felemban
Fabrication process of capacitors and Schottky diodes with nanogap electrodes is explained in this Thesis. The Schottky diode is made with IGZO in the nanogap, whereas the capacitor is made with ZrO2 in the nanogap which acts as the dielectric. Moreover, the electric characterization of both the diode and capacitor was obtained for different frequencies and different diameters. The end result showed that as the frequency increases the diode performance increases, but the capacitance of...

Single-Crystal Halide Perovskites for High Efficiency Photovoltaics

Abdullah Yousef Alsalloum

Understanding the Molecular Basis of Thermopriming in Plants

Natalia Lorena Gorron Serano
Plants acclimate to the changing environmental conditions by adjusting their molecular responses at different molecular levels including genome, epigenome, transcriptome, metabolome, and proteome levels to ensure survival. Plants adapt to abiotic stresses by establishing a ‘stress memory’ of previous exposures to mild stresses. Stress memory helps plants to develop tolerance and survive recurring exposures to the stress conditions. This memory establishes a new cellular state that differs from the state of unexposed naïve plants. This...

The Contrasting Roles and Importance of Dispersal, Horizontal Gene Transfer and Ecological Drift in Bacterial Community Assembly

Adriana Valenzuela-Cuevas
Communities are defined as the ensemble of populations that interact with each other and with the environment in a specific time and location. Community ecology studies how communities assemble, what are the patterns of diversity, abundance, and composition of species, and the processes driving these patterns. It includes four basic mechanisms for the assembly of communities: dispersal, drift, selection, and speciation, with each mechanism influencing how the communities change in a different way. Dispersal, the...

Genome assembly and annotation datasets of the plant growth promoting bacterium Paenibacillus sp. JZ16 isolated from the root endosphere of a pioneer desert plant in Jizan, Saudi Arabia

Abdul Aziz Eida, Salim Bougouffa, Intikhab Alam, Maged Saad & Heribert Hirt
The files associated with this dataset are the GenBank, GFF and protein coding-sequence (CDSs-FASTA) files of a plant growth promoting bacteria isolated from the root endosphere of a pioneer desert plant in Jizan, Saudi Arabia. Genome annotation was carried out using the Automatic Annotation of Microbial Genomes (AAMG) which is an integrated module in the in-house INDIGO-Desert v1.1 pipeline (Alam et al., 2013).

Optimization of Molecularly Imprinted Polymers for Electrochemical Sensing of Non-charged Biological Molecules

Sarah Al Abdullatif
Biosensors monitor physiological activities for diagnosis and treatment of disease. Molecularly imprinted polymers (MIPs) are a viable synthetic approach for molecular recognition in biosensing. For biosensing purposes, the most important properties in MIP optimization are sensitivity and selectivity towards a desired analyte. This study aims to optimize MIP sensitivity and selectivity by varying the amount and type of cross-linker used in the synthesis of cortisol and melatonin. The four cross-linkers tested were trimethylpropane trimethacrylate (TRIM),...

The role of PQL genes in response to salinity tolerance in Arabidopsis thaliana and barley

Mashael Daghash Saeed Alqahtani
Increasing salinity is a worldwide problem, but the knowledge on how salt enters the roots of plants remains largely unknown. Non-selective cation channels (NSCCs) have been suggested to be the major pathway for the entry of sodium ions (Na+) in several species. The hypothesis tested in this research is that PQ loop (PQL) proteins could form NSCCs, mediate some of the Na+ influx into the root and contribute to ion accumulation and the inhibition of...

High Performance Membranes for Solvent Resistant Ultra and Nanofiltration

Bruno Antonio Pulido Ponce De Leon
The aim of this work is the preparation of porous polymeric membranes for liquid separations stable in organic solvents, high temperature and/or extreme acid or basic conditions. Polymeric membranes with these properties could replace more traditional and energy-expensive separation processes like distillation, competing with ceramic membranes due to their easy processability and scalability. A limited library of polymers have been successfully used for decades in water-based applications. They are however unstable in organic solvents without...

Harvesting Clean Water from Air

Renyuan Li
Water scarcity has caused severe impact on the entire ecosphere while the climate change is resulting in high frequency of extreme weather conditions, especially extended period of drought. Due to the even increasing world’s population and the continued societal modernization, water scarcity is now one of the leading global challenges towards the development of human society. On the other hand, atmospheric water, accounting for 6 times the water in all rivers on Earth, is emerging...

Electrochemical CO2 Reduction to Value-added Chemicals on Copper-based Catalysts

Shenghong Zhong
Controlled and selective electrochemical CO2 reduction to hydrocarbons and oxygenates utilizing energy from renewables such as solar energy is a promising alternative approach to store energy in chemical bonds while simultaneously close the anthropogenic carbon cycle, thus to address the twin problems of fossil fuels depletion and environmental challenges. Copper-based electrocatalysts have been demonstrated promising performance for CO2 reduction. However, Cu usually converts CO2 into a mixture, where more than 16 different species have been...

Deep-Ultraviolet Optoelectronic Devices Enabled by the Hybrid Integration of Next-Generation Semiconductors and Emerging Device Platforms

Nasir Alfaraj
In this dissertation, the design and fabrication of deep-ultraviolet photodetectors were investigated based on gallium oxide and its alloys, through the heterogeneous integration with metallic and other inorganic materials. The crystallographic properties of oxide films grown directly and indirectly on silicon, magnesium oxide, and sapphire are examined, and the challenges that hinder the realization of efficient and reliable deep-ultraviolet photodetectors are described. In recent years, single-crystalline heterojunction photodiodes employing beta-polymorph gallium oxide thin films as...

Hybrid Lead Halide Perovskite and Bismuth-Based Perovskite-Inspired Photovoltaics: An In Situ Investigation

Ming-Chun Tang
Ink-based semiconductors that come to mind today include conjugated molecules and polymers, colloidal quantum dots, metal halide hybrid perovskites, and transition metal oxides. These materials form an ink (solution/ suspension/ sol-gel) that can be applied and dried in ambient air to form high-quality films for optoelectronic devices. In this study, we will introduce the current understanding of ink-based lead and lead-free hybrid perovskite and perovskite-inspired thin films. Examples will be presented through time-resolved studies of...

Efficient and Thermodynamically Consistent Numerical Schemes for Porous Media Flow and Multicomponent Transport

Xiaolin Fan
In the first part, efficient and fully mass-conservative numerical schemes for gas flow and multicomponent transport in fractured porous media are studied. The gas flow and multicomponent transport in fracture is rigorously derived and described by reduced fracture modeling. A new IMplicit Pressure Explicit Concentration (IMPEC) scheme is derived for the gas flow and multicomponent transport in fractured porous media. Compared with IMPEC schemes in the literature by which mass-conservation of all species may not...

Compliant Electronics for Unusual Environments

Amani Saleh Saad Almislem
Compliant electronics are an emerging class of electronics which offer physical flexibility in their structure. Such mechanical flexibility opens up opportunities for wide ranging applications. Nonetheless, compliant electronics which can be functional in unusual environments are yet to be explored. Unusual environment can constitute a harsh environment where temperature and/or pressure is much higher or lower than the usual room temperature and/or pressure. Unusual environment can be an aquatic environment, such as ocean/sea/river/pond, industrial processing...

Genetics of Salinity Tolerance in Rice

Nadia Al Tamimi
For more than half of the world’s population, rice (Oryza sativa L.), the most saltsensitive cereal, is a dietary staple. Soil salinity is a major constraint to rice production worldwide. Thus, to feed 9 billion people by 2050, we need to increase rice production while facing the challenges of rapid global environmental changes. To meet some of these challenges, there is a vital requirement to significantly increase rice production in salinized land and improve photosynthetic...

Engineering of Pseudocapacitive Materials and Device Architecture for On-Chip Energy Storage

Qiu Jiang
The emergence of micropower-type applications such as self-powered sensors and miniaturized electronic systems has increased interest in on-chip electrochemical energy storage such as microsupercapacitors. Microsupercapacitors (MSCs) are high rate and high power yet miniaturized versions of macroscopic supercapacitors. MSCs with planar configuration have higher power density at potentially comparable energy density to thin-film batteries, while possessing essentially infinite cycle life. They could also offer compatible integration with smart electronic devices on an integrated chip (IC)....

Gasoline Combustion Chemistry in a Jet Stirred Reactor

Bingjie Chen
Pollutant control and efficiency improvement propel the need for clean combustion research on internal combustion engines. To design cleaner fuels for advanced combustion engines, gasoline combustion chemistry must be both understood and developed. A comprehensive examination of gasoline combustion chemistry in a jet stirred reactor is introduced in this dissertation. Real gasoline fuels have thousands of hydrocarbon components, which complicate numerical simulation. To mimic the behavior of real gasoline fuels, surrogates, composed of a few...

Gain Enhancement Techniques for mm-wave On-chip Antenna on Lossy CMOS Platforms

Haoran Zhang
Recently, there is great interest in achieving higher-level integration, higher data rates, and reduced overall costs. At millimeter-wave (mm-wave) bands, the wavelength is small enough to realize an antenna-on-chip (AoC), which is an ideal solution for high compactness and lower costs. However, the main drawback of AoC is the low resistivity (10 Ω-cm) Si substrate used in the standard CMOS technology, which absorbs most radio-frequency (RF) power that was supposed to be radiated by the...

Characterization of Red Sea Cyanobacteria Aimed for Cell Factory Applications in Saudi Arabia: Synechococcus sp. RSCCF101.

Yi Mei Ng
Saudi Arabia is highly accessible to marine water, receives year-round availability of sunlight and generates a high annual carbon dioxide emission, all of which are justifications that merits the deployment of cyanobacterial cell factories. However, industrial cyanobacterial strains capable of thriving in conditions of the Arabian Peninsula are currently lacking. Given the fact that native cyanobacteria from the Red Sea are adapted to the local conditions, they are therefore good cell factory candidates where their...

Numerical study of linear and nonlinear problems using two-fluid plasma model in one dimension

Bhargav Mantravadi
The ideal two-fluid plasma model is a more generalized plasma model compared to the ideal MHD and it couples the ion and electron Euler equations via Maxwell's equations. Two-fluid plasma model is essential when the ion and electron fluids are at different temperatures. In this work, a fundamental investigation on the effect of non-dimensional light speed, ion-to-electron mass ratio and plasma beta on the plasma dynamics in the Brio-Wu shock tube Riemann problem is presented....

Theoretical and Experimental Studies of Optical Properties of BAlN and BGaN Alloys

Feras S. AlQatari
Wurtzite III-nitride semiconductor materials have many technically important applications in optical and electronic devices. As GaN-based visible light-emitting diodes (LEDs) and lasers starts to mature, interest in developing UV devices starts to rise. The search for materials with larger bandgaps and high refractive index contrast in the UV range has inspired multiple studies of BN-based materials and their alloys with traditional III-nitrides. Additionally, alloying III-nitrides with boron can reduce their lattice parameters giving a new...

Development of Reusable heterogeneous Catalysts for Sustainable formic acid production and methanol utilization

Ding-Jier Yuan
The green production of formic acid and utilization of methanol over heterogeneous catalysis system were investigated in this study. The heterogeneous catalysts are widely used in the chemical industry. They offer high stability and reusability which can enhance the production ability and lower the production cost, it can be considered as the sustainable energy solution for the future. In this work, we demonstrated several different heterogeneous catalysts for sustainable formic acid production and methanol utilization,...

Registration Year

  • 2019

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  • King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia