Physical Sciences and Mathematics Commons^™

First-Principles Study Of Doping Effects On Ferroelectricity And On Rashba Spin Splitting, Zegnet Yimer Muhammed

Graduate Theses and Dissertations

In this dissertation, we have thoroughly studied the effect of chemical and charge dopingon ferroelectrics (PbTiO3 and BaTiO3) and Rashba type semiconductor (BiTeI). In the first project, We investigate the polar instability and soft modes in electron-doped PbTiO3 using linear-response density functional calculations. Because, metallicity and ferroelectric-like polar distortion are mutually non-compatible, and their coexistence in the same system is an intriguing subject of fundamental interest in the field of structure phase transition. However, it is unclear what mechanism may extend the limit of metallicity that allows polar distortion. We find that ferroelectric instability can remarkably sustain up to an …

A Study On Interactions Between Metal-Organic Frameworks And Biological Materials, Josh Phipps

Graduate Theses and Dissertations

Metal-organic frameworks or MOFs are an extremely useful tool in many areas of applications. Their popularity in recent years has arisen from their high efficiency in catalytic chemical reactions. This is made possible due to their porous interior and the ability of the MOFs components to be functionalized. These same traits make MOFs excellent for use in protein encapsulation or immobilization and have the potential to become excellent drug carriers. Their development in this utilization has been limited dramatically compared to MOFs chemical applications. This is due in part to the nature of biological processes taking longer to study, but …

The Binding Of The Micronutrient Transition Metals To The Alkylation Products Of Chemical Warfare Agent, Sulfur Mustard, And Thiols, Potentially Giving New Understanding To Physiological Effects Of Exposure And Increased Toxicity, Colin O'Donnell

Graduate Theses and Dissertations

Model compounds, 3,6,9-trithaiundecane-1,11-dicarboxylic acid (TTDPA), 2,5,8-trithianonane-1,9-dicarboxylic acid (TTDAA), and 1,11-diamide-3,6,9-trithiaundecane (TTDAce), closely related to the adducts formed by cysteine alkylation of the chemical weapon, sulfur mustard, were synthesized. It is shown that TTDPA forms complexes with key metal micronutrients: copper, nickel, cobalt, manganese, and zinc. Though the strength of binding to TTDPA varies, the complexes in many cases precipitate from solution. All metals produced a visible precipitate upon interaction with TTDPA under the conditions tested, however only Cu2+, Mn2+, and Zn2+ produced enough to be measured. The mass of formed precipitate seemed to peak at an equimolar ratio of TTDPA …

Unassisted Photoelectrochemical Solar-To-Hydrogen On Cubi2o4 Photocathodes Using Glycerol As A Sacrificial Oxidant, Caroline Eddy

Chemistry & Biochemistry Undergraduate Honors Theses

The need to decarbonize society has driven the development of alternative energy technologies. Solar panels are capable of generating electricity at large scale and at competitive costs to fossil fuels, such as coal or natural gas. However, they are only capable of generating electricity when the sun is out. It is therefore necessary to understand how to store that energy for on-demand use. It is also desirable that the storage be portable, lightweight, and compatible with transportation infrastructure like fossil fuels are. A very desirable chemical fuel is H₂ which can be produced simply by water electrolysis. Production of …

Using Molecular Dynamics Simulations To Decipher Mechanistic Details Of Biomolecular Processes Of Biology And Biotechnology Oriented Applications, Adithya Polasa

Graduate Theses and Dissertations

Researchers in chemistry and biology often utilize computer simulations, in conjunction with experimental data, to model and predict the structures, energies, kinetics, processes, and functions of the systems that are their focus of study, ranging from single molecules to whole viruses. Here, we use molecular dynamics (MD) techniques to gain a deeper understanding of biomolecular processes in biology and biotechnology-oriented applications. Using a mixture of equilibrium and non-equilibrium MD simulations, this work describes the insertion process of YidC at the atomic level. In order to better comprehend the insertion process, several docking models of YidC-Pf3 in the lipid bilayer were …

Hierarchical Structure And Material Integration For Electrocatalytic Co2 Reduction, Hamed Mehrabi

Graduate Theses and Dissertations

CO2 released by the combustion of fossil fuels is driving significant changes to the earth’sclimate. The natural cycle for removing CO2 from the atmosphere, namely photosynthesis, cannot keep up with the rate at which it is being added. Developing engineering approaches to remove CO2 from the atmosphere is becoming essential to reduce these effects. Removal leads to further issues of carbon sequestration and favorable CO2 reuse strategies, including the electrochemical transformation of recovered CO2 to useful products such as fuels and materials. Copper is an important electrocatalyst for the CO2 reduction reaction (CO2RR) because of its unique capability for producing …

Visible Light-Assisted Deconstruction/Refunctionalization Of Strained And Unstrained N-Cycloalkylanilines, Elvis Duah Boateng

Graduate Theses and Dissertations

The exploitation of ring strain as a driving force to facilitate chemical reactions is a well-appreciated principle in organic chemistry. Of the strained carbocycles frequently explored in this respect, cyclopropane ring systems have drawn considerably more interest among synthetic chemists than their homolog, the cyclobutane ring systems, even though the strain energy of cyclobutane (26.7 kcal/mol) is similar to that of cyclopropane (27.5 kcal/mol). We have previously developed a [4+2] annulation reaction for the synthesis of aniline-substituted six-membered carbocycles under photoredox catalysis via the oxidative cleavage of N-cyclobutylanilines. The key reaction involved in this method is a ring-opening process of …

Catalytic Activity Of Tungsten-Dioxo And Tungsten-Diimido Complexes, Kayla Denike

Graduate Theses and Dissertations

Due to the significant decline in the availability of petrochemical resources and the increasing demand for the useful olefin mixtures extracted from oil, a sustainable and efficient alternative to these materials has become vital. Fortunately, renewable biomass derived materials may serve as a sustainable solution to the limited resources problem. Molecules derived from the degradation of biomasses are highly oxygenated and highly functionalized. Developing processes to efficiently defunctionalize these oxygen-rich materials will lead to potential up-conversion to carbon chemicals. Homogeneous catalytic deoxygenation processes present an opportunity to access valuable carbon commodity chemicals from biomass derived polyols. This dissertation details the …

Hierarchically Structured Photoelectrodes Via Atomic Layer Deposition, Justin Rowan Reed Demoulpied

Graduate Theses and Dissertations

In the search for a sustainable method to meet increasing energy needs, solar energy emerges as an underutilized, plentiful resource. Solar intermittency and requirements for transportation necessitate storing solar energy in the form of chemical bonds via artificial photosynthesis. Photoelectrochemical (PEC) water splitting generates hydrogen fuel from solar energy and water. A semiconducting material that successfully meets the complex requirements for building an industrially scalable PEC device has yet to emerge. This is leading to a reevaluation of materials previously overlooked within PEC research, mainly materials with limitations such as minimal charge carrier mobility and propensity to corrosion under illumination …

Colloidal Monolayers For Concentration Light In Ultra-Thin Semiconductor Layers, Rachel Cherry

Graduate Theses and Dissertations

Thin film semiconductors are used as photoconductive absorber layers for the development of broadband terahertz generation. Using a femtosecond laser pulse, the generation of a transient increase in the conductivity occurs by photoexciting conduction band electrons in the semiconductor. These thermalize through the emission of terahertz radiation. The route to terahertz generation is not particularly efficient as significant losses come from the absorption in the substrate that is beneath the photoconductive antenna layer. This work explores the application of hexagonally close-packed monolayers of chemically synthesized nanospheres as a potential light concentration method for ultra-thin films of GaAs and black phosphorus …

Investigation Of The Binding Domain Interfaces Of The C-Terminus Of The Albino3 Insertase And The 43kda Chloroplast Signal Recognition Particle Subunit Via Single Molecule Förster Resonance Energy Transfer, Amanda Tomanek

Chemistry & Biochemistry Undergraduate Honors Theses

Fluorescent labeling is a technique used for visualizing functional groups contained in biomolecules by fluorescence imaging. This technique was used in this project to analyze post-translational targeting of light-harvesting chlorophyll-binding proteins (LHCP), which are the core complexes that harvest sunlight to drive photosynthetic electron transfer. This protein is synthesized in the cytosol and post-translationally targeted to the stroma of chloroplasts. CpSRP43 is a signal recognition particle (SRP) subunit unique to chloroplasts, which has been shown to interact with the stroma-soluble C-terminus of the thylakoid-bound Albino3 insertase (Alb3-Cterm). In the chloroplast stroma, targeting to thylakoids is performed via the cpSRP pathway …

Introduction Of Human Acidic Fibroblast Growth Factor (Fgf1) Variant With Increased Stability And Bioactivity, Azadeh Tavousi Tabatabaei

Graduate Theses and Dissertations

Human acidic Fibroblast Growth Factor 1 (FGF-1) involves in a broad spectrum of biological processes, including cell growth, proliferation, differentiation, migration, angiogenesis, wound healing, and embryonic development. hFGF1 non-selectively binds to cell surface hFGF receptor isoforms to elicit these cell-signaling processes. Since hFGF1 plays a significant role in tissue repair activity, that is a prime candidate for novel wound healing therapeutics. However, hFGF1 has been found to unfold near physiological temperature due to a strong electrostatic repulsion created by a dense cluster of positively charged amino acids near the c-terminus. The problem not only leads to proteolytic degradation of the …

“Translation Of Hdac6 Pet Imaging Using [18f]Ekz-001 – Cgmp Production And Measurement Of Hdac6 Target Occupancy In Nhps” – A Review, Dania Rahal

Chemistry & Biochemistry Undergraduate Honors Theses

The inhibition of histone deacetylase 6 (HDAC6) has been reported to alleviate the effects of neurodegenerative diseases such as Alzheimer’s disease. The brain-penetrant PET radioligand [¹⁸F]EKZ-001 has high affinity and selectivity towards HDAC6 and therefore suggests great promise in therapeutic treatment studies and development for neurodegenerative diseases. “Translation of HDAC6 PET imaging using [¹⁸F]EKZ-001 – cGMP production and measurement of HDAC6 target occupancy in NHPs” has achieved an effective, fully automated method of producing [¹⁸F]EKZ-001 in compliance with current good manufacturing practices (cGMP) to support the translation of [¹⁸F]EKZ-001 PET for …

The Design Of A Efficient Production And Purification Of Fibroblast Growth Factor 2, Mandeep Kaur

Chemistry & Biochemistry Undergraduate Honors Theses

Chronic wounds pose a major problem in the United States with an estimate of twenty-five million dollars a year spent on associated treatments. Growth factors can be used as a potential treatment for chronic wounds since they promote cell proliferation and angiogenesis. This study employs one specific growth factor, fibroblast growth factor 2 (FGF2) so that it could potentially be used in future treatment. Wild-type FGF2 is thermally unstable, and it has a mean elimination time of 7.6 hours. This study attempted to improve upon its stability through a mutation on the heparin binding loop. The mutation performed was K134E. …

Fabrication Of Mof Films Of Uio Or Pcn Type Through Layer-By-Layer Molecular Deposition As Well As Bulk Deposition For Catalytic Applications, John Ozdemir

Graduate Theses and Dissertations

Metal-organic frameworks (MOFs) are crystalline, porous materials comprised of symmetric organic linkers coordinated to positively charged metal atoms or metal oxide nodes. This dissertation uses strategies in crystal engineering to advance the study of functional MOFs with emphasis on thin film deposition. The first chapter of this dissertation will introduce the field of reticular chemistry to the reader and describe synthetic efforts to develop useful building blocks for MOF materials: namely porphyrin macrocycles and carboxylate capped zirconium-oxo and hafnium-oxo clusters. The building blocks for MOFs developed in the first chapter will be employed in the second and third chapters through …

Understanding Interfacial Reactions Initiating On Electrode Materials For Energy Storage Technologies, Jingnan Li

Graduate Theses and Dissertations

Since the first generation of lithium-ion batteries featured lithium cobalt oxide cathode and carbon anode commercialized in the 1990s, the high-capacity materials with lower cost are in demand to further increase the battery energy density. Lithium metal and silicon anode are promising high-capacity anode materials to achieve next-generation lithium batteries. However, both the materials actively react in electrolytes and suffer from dramatic volume change. Therefore, a reliable passivation layer at the electrolyte/electrode interphase (i.e., solid electrolyte interphase, or “SEI”) is required to support the long-term cycling of both materials. Cetrimonium hydro fluoride (CTAHF2) has been proposed and synthesized as an …

Diffusion Of A Salt In An Aqueous Media, Aldaly Pineda Hernandez

Chemical Engineering Undergraduate Honors Theses

Diffusion is defined as the net transfer of a molecule from a high concentration region to a low concentration region. The concept of diffusion is used in a very important process called "desalination." Desalination is a separation process used to reduce the salt content dissolved in brackish water to make it suitable for human consumption, irrigation, and industrial use.

In desalination plants, it is important to monitor the constantly changing salt content of water, partly due to the diffusive effect. The main purpose of this experiment was to study the diffusion of NaCl in water at two NaCl concentrations. The …