Physical Sciences and Mathematics Commons^™

Monitoring Of Soil Moisture And Human Breath Using Colorimetric Humidity Sensors, Emily Bialka

Theses and Dissertations

The monitoring of soil moisture is essential to optimize plant growth, harvest, and water use, and respiration monitoring is one of the major vital signs of human health. Current soil moisture sensors are either costly or ineffective, and current breath sensors which also detect humidity levels are electronic-based with narrow humidity ranges. The following study targets these two needs by developing a cost-effective, high-sensitivity soil moisture sensor and breath monitor. Responsive interference coloration humidity sensors which utilize thin-film interference are applied to track soil moisture content over time, and to monitor breath humidity levels and respiratory rate in various scenarios. …

Chemical Investigation Of Camu Camu (Myrciaria Dubia) Leaves And Roots, Jorge L. Flores

Theses and Dissertations

Flores, Jorge L., Chemical Investigation of Camu Camu (Myrciaria dubia) Leaves and Roots. Master of Science (MS), December, 2020, 45 pp., 8 Tables, 28 Figures, 21 references, 12 titles.Being the largest on the planet, the Amazon rainforest also has the greatest biodiversity of plant life on earth. In the lowland regions of the Amazon grows the Peruvian camu camu (Myrciaria dubia) plant. A short and shaggy shrub, camu camu produces a tasty but sour fruit. Camu camu’s berry-like fruit is widely consumed by the native people of the Amazon. Its distinguished richness in vitamin C, as …

Applications Of Vanadium Phthalocyanine In Catalytic, Acid-Based Medium To Couple Sugar Molecules, Juan Ricardo Luna

Theses and Dissertations

The vanadium-substituted tetraazatetrabenzoporphyrin, vanadium phthalocyanine, was synthesized via reflux and characterized using FITR and XRD analysis. Subsequent to synthesis, the vanadium phthalocyanine was studied as a catalyst in redox reactions to convert fructose to different molecules, the products were predominately levulinic methyl ester and heptadionic acid. The ability to convert fructose to other compounds, such as alkyl levulinic derivative, is an important process to help eliminate reliance on traditional chemical feed stocks and promote alternative fuels. Levulinic acid has been commonly used as a starting material in the synthesis of biofuels and a precursor for pharmaceuticals, plasticizers, THF derivatives, γ-valerolatone. …

Uptake Analysis Of As(Iii) And As(V) By Cassia Fistula Seedlings, Valeria Velazquez

Theses and Dissertations

The natural and anthropogenic contamination of water by arsenic has become a major concern to the environment and public health. Phytoremediation is an attractive alternative to ecologically friendly remove contaminants at a potential high efficiency and low cost. Absorption of As(III) and As(V) was evaluated by the measuring the content of arsenic in the roots, leaves and stems Cassia fistula grown under controlled conditions in a hydroponics system. After seeds were germinated, the plants were grown in Hoagland nutrient solution individually supplemented with 1, 2, 5 ppm of As(III) and As(V). After two weeks of exposure, samples of leaves, roots, …

Exploration Of Vase As An Extraction Method For Emerging Disinfection By-Products And Acidic Methanol As A Safe And Effective Derivatization Method For Haloacids, Madison Leigh Kilpatrick

Theses and Dissertations

This project aims to create an environmentally friendly, robust, and efficient extraction and preconcentration method in both the detection and quantification of various disinfection by-products (DBPs). Vacuum assisted sorbent extraction (VASE) is a newly developed method in the extraction of both volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs). This extraction method is paired with a Thermo Scientific TSQ Quantum Triple Quadrupole GC-MS system for the quantification of DBPs. VASE outperforms current DBP extraction methods, with liquid-liquid extraction (LLE) being the most used alternative, because of its minimal use of solvent, high level of automation, and over-all ease of …

Plasmonic Metallic And Semiconductor Nanomaterials, Mengqi Sun

Theses and Dissertations

The earliest account of localized surface plasmon resonance (LSPR) has to date back to the ancient age of Rome in 400 A.D. The famous glass of Lycurgus cup told the story of unique light-and-matter interaction at the nanoscale that confines the electromagnetic field resonance at its surface and therefore allows LSPR feature to noticeably arise. The conventional metallic LSPR nanomaterials, like Au and Ag nanoparticles attract constant attentions due to their synthetic simplicity, chemical robustness, and visible spectral response. Its ability to generate sensitive dielectric sensing of the surroundings, strong electromagnetic field and active charge carriers upon optical excitation triggered …

Development Of Axial-Chiral Lewis Base Catalysts For Asymmetric Synthesis, Carlyn Louise Reep

Theses and Dissertations

Asymmetric Synthesis has become an essential tool to provide materials necessary to our everyday lives. The asymmetric formation of carbon-carbon bonds is the most important process in the construction of asymmetric organic molecules as this is how the structure/shape of a molecule is formed. Synthetic chiral molecules exist as agrochemicals, food additives, and pharmaceuticals, among other applications. As the demand for these materials has increased along with the growing population and scientific/technological advancements in these areas, the need for sustainable and efficient synthetic methods has come forefront as a scientific challenge. Chlorosilanes have emerged as an attractive reagent class for …

Developing And Understanding Catalysts For Organic Synthesis, Shelby Dickerson

Theses and Dissertations

Organic synthesis relies on improving catalyst designs and understanding reaction mechanisms for the advancement of the field. This dissertation will describe projects in both of these areas. First it will cover new photocatalysts in the aim of maintaining reactivity while increasing solubility in less polar solvents, and second understanding the importance of intermolecular interactions between new nucleophilic catalysts and substrates.

Photocatalysis has become a major focus as a sustainable pathway for chemical reactions with visible light photocatalysts performing a large range of reactions such as redox reactions, cyclization reactions, and energy transfer reactions. Chapter 1 will discuss classes of organic …

Characterization Of Ph – Responsive Nanocage Based On The Ferritin Iron Storage Protein, Satyam Singh

Theses and Dissertations

The iron-storage protein ferritin (Ftn) assembles into a protein cage structure with 24 subunits and octahedral (4-fold, 3-fold, 2-fold) symmetry. Each monomeric subunit contains a robust four-helix bundle fold. The fully assembled Ftn structure has a high degree of thermal stability (up to 100°C), a mono dispersed size (12 nm in diameter), and a large central cavity (7-8 nm in diameter). The central cavity stores ferric iron in phylogenetically diverse group of organisms, including humans. The central cavity has been used for encapsulation of cargoes such as other metals, contrast agents for imaging, small molecule drugs for therapy, …

Colloidal Semiconductor Quantum Dots: Solution Processing And Heterostructure-Based Optoelectronics, Mathew L. Kelley

Theses and Dissertations

Colloidal semiconductor quantum dots (QDs) are attractive candidates for high-efficiency solar cells and uncooled multiplexed photodetectors due to their favorable characteristics including large absorption cross-sections, size-tunable bandgap energies spanning the ultraviolet (UV) to short wave infrared, and solution processability. These QD-based optoelectronic devices operate on the basis of efficient photogenerated charge migration within QD solids and charge separation and recombination at electrical junctions, underscoring the need for (1) processing strategies that facilitate charge transport and (2) characterization techniques that robustly interrogate charge separation at QD interfaces. Here, my work on the post-synthetic processing and surface modifications of several semiconductor QDs, …

Alkyne Cyclization Involving A Zwitterionic Hexaruthenium Carbido Carbonyl Complex And The Synthesis Of The First-Nitrido Heterometallic Carbonyl Cluster Complexes, Nutan Damodhar Wakdikar

Theses and Dissertations

Chapter 1 introduces two related topics with the primary focus on the background of zwitterions and the conceptual understanding of a metal-complexed zwitterion. It also discusses the potential of a metal-complexed zwitterion for a carbon-carbon bond formation reaction. Synthesis of the metal carbonyl cluster, Ru6(µ6-C)(µ-CO)(CO)16, is also discussed in detail. Then, the background with the importance of heterometallic cluster complexes is discussed with the help of various examples used for catalysis.

The reaction of hexaruthenium carbido carbonyl cluster, Ru6(µ6-C)(µ-CO)(CO)16, with C2H2 and Me3NO yielding first examples of two new zwitterionic complexes, Ru6C(CO)15(μ−η2−C2H2NMe3), 2.2, and Ru6C(CO)14(μ3−η4−C4H4NMe3), 2.3, are presented in Chapter …

Characterization Of A High Affinity Glutathione Transporter And Its Impact On Glutathione Depleted Saccharomyces Cerevisiae, Tirthankar Bandyopadhyay

Theses and Dissertations

Thiol-disulfide redox homeostasis is integral for maintaining the redox status of proteins and other thiol-containing molecules within the cell. Among the many antioxidants and detoxifying enzymes and small peptides, glutathione (GSH) has proven to be critical for the preservation of function and structural integrity of the cell due to its functionality in areas like oxidative protein folding, thiol redox control, reactive oxygen species (ROS) and xenobiotics removal as well as iron regulation and Fe-S cluster biogenesis. Therefore, our studies are aimed at elucidating the factors that control GSH trafficking and metabolism in the model eukaryote Saccharomyces cerevisiae (baker’s yeast). Using …

Engineered Nanostructured Nitrogen-Doped Carbon Network (Ndc) Electrodes With Unprecedented Cycling Stability For Water Capacitive Deionization In Harsh Conditions, Soha Essam Anwar

Theses and Dissertations

Capacitive deionization (CDI) is a feasible low-cost desalination technique for low-to-medium (brackish) salinity water. However, cycling stability and regeneration of the CDI electrodes are the bottlenecks hindering the practical application of the technology on large scale. Oxidation of the electrodes during the sequential adsorption-desorption processes is one of the most challenging problems hindering their long-term cycling performance. Herein, we demonstrated the ability to design and fabricate exceptionally stable CDI electrodes via a one-pot pyrolysis protocol. The optimized pyrolysis of nitrogen-carbon precursors at different temperatures enabled the fabrication of carbon materials with a controlled amount nitrogen dopant (NDCs) with exceptional cycling …

Fullerene And Tungsten Oxide Nanostructures-Based Electrocatalysts For All-Vanadium Redox Flow Batteries, Farah Ahmed El Diwany

Theses and Dissertations

The vanadium redox flow battery (VRFB) is one of the most promising long-term energy storage solutions mainly due to its long service life and the independence of its energy capacity on power rating and vice versa. However, its relatively high capital cost limits its widespread deployment. Economic analysis reveals that a high-power density VRFB with decreased cell stack size can dramatically reduce the cost. The energy efficiency of a VRFB primarily depends on the kinetics of vanadium redox reactions that take place in the stack. Therefore, studying the effect of surface chemistry of electrodes on the kinetics of each …

Determination Of The Metabolism, Distribution, And Concentration Of Calcitroic Acid, Elliot Di Milo

Theses and Dissertations

Near the turn of the 20th century scientist were beginning to discover compounds thatwere essential for humans beyond the previous establish, protein, grains, and fat. This ushered in a new field of studying a class of molecules that were considered “vital amines” later shortened to vitamins. Vitamin D was the fourth of this new class of compound that was identified and over the next decades was shown to play a vital role in the homeostasis of calcium and phosphorous. The dominant active form of vitamin D is formed within the body through a series of oxidation reactions acting upon its …

Approach Toward The Total Synthesis Of Some Sarpagine Related Indole Alkaloids: Histrixnine, Gelsempervine A, Gelsempervine B, O-Methylmacusine B & 19,20-Dihydro-O-Methylmacusine B,Design, Synthesis & Biological Study Of Some Novel Gamma-Aminobutyric Acid Type (Gabaa) Receptor Ligands, Md Zubair Ahmed Khan

Theses and Dissertations

Indole alkaloids are chemically, biologically and commercially significant, as well as diversely distributed important group of natural products. These are of prominence because of their resemblance with various biologically essential molecules including tryptophan, tryptamine, and serotonin. The Sarpagine type indole alkaloids comprise one of the most diverse series of indole alkaloid natural products. These indole alkaloids are primarily isolated from three plant families: Apocynaceae, Rubiaceae, and Loganiaceae which have been used in traditional and folk medicines in many countries around the world. Biological screening of these alkaloids is not always possible, presumably, due to the paucity of the isolated natural …

Part I: Development Of Small-Molecule-Based Probes For The Vitamin D Receptor; Part Ii: Development Of A Scalable Manufacturing Process For Orcein Dye, Tania Roseann Mutchie

Theses and Dissertations

PART I:The vitamin D receptor (VDR) is a ligand-dependent transcription factor and member of the nuclear hormone receptor superfamily. VDR is expressed in the epithelia of endocrine organs, digestive system, bronchi, kidneys, and thymus, as well as being present in leukocytes and bone cells. Cell proliferation, cell differentiation, and immunomodulation, along with calcium and phosphate homeostasis, are all processes regulated by the receptor. Within the cell, VDR can be membrane-bound or located in the nucleus. Nuclear localization of VDR transpires following the binding of vitamin D metabolites, the most active of which is 1α,25-dihydroxyvitamin D3 (calcitriol). Within the nucleus, interactions …

Chapter 1: Part A: A Unique Approach Of Preparing 3,3-Disubstituted Oxindoles From Acyclic Tetrasubstituted Aldehydes: Total Synthesis Of (-)-Coerulescine And (-)-Coixspirolactam A, Chapter 1: Part B: Synthetic Scope Of Brønsted Acid Catalyzed Reactions Of Carbonyl Compounds And Ethyl Diazoacetate,, Md Shahnawaz Ali

Theses and Dissertations

CHAPTER 1: PART A: A UNIQUE APPROACH OF PREPARING 3,3-DISUBSTITUTED OXINDOLES FROM ACYCLIC TETRASUBSTITUTED ALDEHYDES: TOTAL SYNTHESIS OF (-)-COERULESCINE AND (-)-COIXSPIROLACTAM A(-)-Coerulescine and (-)-coixspirolactam A, two naturally occurring compounds characterized with an all-carbon quaternary center containing a spirooxindole, have been synthesized asymmetrically. The key feature of their total synthesis involves a novel rational construction of the chiral 3,3-disubstituted oxindole core from the acyclic chiral tetrasubstituted aldehyde. The later scaffold was prepared in high enantioselectivity (up to 86%) from the ethyl 3-hydroxy-2-(2-nitrophenyl)acrylate 1 by exploring both intermolecular and intramolecular Pd-mediated asymmetric allylic allylations (Pd-AAA). A through optimization of these approaches is …

The Aqueous Stability Of N-Acyl-L-Homoserine Lactones, Their Affinity For Cyclodextrin Inclusion, And The Investigation Of A Catalyst For Their Hydrolysis, Eric William Ziegler

Theses and Dissertations

Many bacteria demonstrate population-density dependent gene expression, a phenomenon known as quorum sensing, to regulate phenotypes that, if expressed by an individual bacterium, would be ineffective. While some of these phenotypes are innocuous (e.g., exhibiting bioluminescence), certain bacteria employ quorum sensing regulated phenotypes in their pathogenesis. Traditionally, infections by these pathogens have been treated with antibiotic therapies. However, with the emergence of multidrug resistant strains, alternative strategies are being considered for attenuation of quorum sensing regulated traits that do not apply selective pressures. Macrocycles — in particular the cyclodextrins — that are capable of forming inclusion complexes with Gram-negative quorum …

Metastable State Photoacids And Ultrasound Responsive Carbon Monoxide Releasing Polymer Micelle, Osamah Zaid Saleh Alghazwat

Theses and Dissertations

This dissertation described my Ph.D. work on the development of a novel metastable state photoacids (mPAH), which can be activated by near infrared light and a reversible mPAH switched by different wavelengths of light. Also, it described the development of a micelle that responded to ultrasound to localized carbon monoxide CO delivery. An introduction of metastable state photoacid is given in Chapter 1. In Chapter 2, described my work on the development of a novel mPAH, which can be activated by near infrared light is an important factor for various biological functions. mPAH was designed and synthesized with a donor-acceptor-donor …

Design And Synthesis Of Polymeric Metastable State Photoacid And Photo Co-Releasing Materials, Adnan Abdallah Muftah Elgattar

Theses and Dissertations

Metastable state photoacids (mPAHs) are molecules that possess a photoinduced metastable state with high acidity and good reversibility. The metastable state lasts long enough to produce a high proton concentration, which can drive various proton transfer processes. MPAHs have been intensively studied in recent years and applied to different chemical, material, biomedical areas. Covalently linking many mPAHs in a polymer allows the generation of a local proton concentration higher than that of the overall system. This dissertation described my PhD work on the synthesis of mPAH polymers using different radical and ring-opening polymerization methods. These polymers can repeatedly produce a …

Removal Of Arsenic (Iii) And Arsenic (V) From Aqueous Solution Via Solanum Lycopersicum Phytoremediation And Essential Nutrient Analysis, Grecia W. Garcia Salazar

Theses and Dissertations

ICP-OES was used to investigate the uptake of arsenic (V) and arsenic (III) from aqueous solution using tomato seedlings. The effect of arsenic on essential nutrient uptake by tomato was analyzed. The experiment was performed at three levels of arsenic: 1ppm, 2 ppm and 5 ppm [added as sodium arsenate (Na3AsO4) and arsenic trioxide (As2O3)], in nutrient solution. Plants remained in solution for two weeks. Arsenic accumulation depended on arsenic concentration in solution, when exposed to higher arsenic concentrations the plant uptake increased. The highest arsenic accumulation was found in roots, followed by stems and leaves in that order. Essential …

Virtual Screening For Potential New Chemotherapeutic Agents For The Gpr119 Receptor, A Target For Type Ii Diabetes, Jennifer Lizeth Bravo

Theses and Dissertations

Three frames from a molecular dynamics simulation run of a GPR119 receptor homology model were used for this study. The homology model was validated by virtually screening 76 known GPR119 receptor. 85% of these agonists bound to the receptor. Following the validation, 21,000 molecules were selected for the virtual screening study. 862 ligands came from the GPCR Selleckchem/Prestwick library, 42 compounds from the Prestwick Phytochemical library, 20,000 compounds from the ZINC library, plus four molecules from the literature. All ligands were built, geometry-optimized, and docked in the GPR119 models using a protocol combining High Throughput Virtual Screening, Standard Precision, and …

Investigation Of The C—Cn Bond Activation Of Fluorinated Benzonitriles With [Ni(Dmpe)] And Dft Benchmarking Study With [Ni(Dippe)], Dominique C. Gallegos

Theses and Dissertations

Carbon-carbon bond activation has become a rapidly growing area of research due to its extensive range of applications. Despite the significant progress that has been made in this field, the cleavage of kinetically inert and thermodynamically stable C—C σ-bonds under mild homogeneous conditions remains a challenge. The activation is primarily limited to systems in which either relief of strain or aromatization serves as a driving force. A notable exception to this is the oxidative addition of unstrained C—CN bonds of nitriles. In this study, we are looking at the effect of fluoro substituents. We hypothesized …

Limits Of Variationality In Full Configuration Interaction For The H2 Model System, Oscar Obed Rodriguez Vargas

Theses and Dissertations

We proposed a framework for exploring the limits of variationality in full configuration interaction (FCI) calculation of molecular electronic structure. We performed FCI calculations on the minimal basis (STO-3G) H2 model for the energy, gradient, and derivative coupling. These calculations were validated by finite difference. These quantities were recalculated with controlled injection of error in the FCI coefficient. The gradient was observed to be highly sensitive to error, while the energy and derivative coupling were robust to errors in the coefficients of nearly 10%. This study lays the groundwork for calculation of other derived quantities, such as the Hessian, adiabatic …

Flexible And Surface Modified Znsno3 Nanocubes For Enhanced Piezoelectric Power Generation And Wireless Sensory Application, Sk Md Ali Zaker Shawon

Theses and Dissertations

Piezoelectric systems and their mechanisms are held in high regard, due to their cost-effective structure and mechanical proficiency to harvest renewable energy. In the present article, we propose an aluminum-doped zinc stannate (ZnSnO3) piezoelectric nanogenerator that can be employed for the harvest of energy and sensory applications. In order to ensure and further enrich the piezoelectric mechanics and product outcome in our device, ZnSnO3 was doped with 1 wt% to 5 wt% of aluminum nanoparticles. We reported that 2 wt% of aluminum-doped ZnSnO3 showed the highest electrical output in terms of open circuit voltages and short circuit current.

The nanogenerator …

A Study Of Nanogenerator Based Flow Sensor, Farzana Tasnim

Theses and Dissertations

The utilization of kinetic energy from fluid flow to power sensory systems is experiencing an all-time high research focus. Invention of nanogenerators have fueled this research focus with unprecedented flexibility of applications. Many studies have reported on utilizing the mechanism of nanogenerator for sensing fluid flow. In this short work, we have summarized different types of self-powered nanogenerator-based flow sensors and their applications. We have also classified the use of Nanogenerator based flow sensors in different fields, such as Bio-medical Application, Fluid velocity sensing, and Chemical Detection. In the Bio-medical field, the flow sensor can be used for the patient’s …

Structure & Function Of Enzymes In Two Uncharacterized Gene Clusters From Pseudomonas Brassicacearum & Streptomyces Griseofuscus, Lamia Tabassum Badhon

Theses and Dissertations

Pyridoxal 5’-phosphate (PLP)-dependent enzymes harness this versatile cofactor to catalyze a variety of reactions including transamination, decarboxylation, racemization and various elemination/subsitution reactions. Several years ago, a new class of PLP-dependent enzymes was discovered that uses PLP and molecular oxygen to catalyze the 4-electron oxidation of L-arginine to 4-hydroxy-2-ketoarginine. Work with the prototypical enzyme of this class, MppP from Streptomyces wadayamensis (SwMppP), showed that the dioxygen consumed during the reaction is reduced to hydrogen peroxide, and that the hydroxyl group installed in the product derives from water. Thus, SwMppP is an L-arginine oxidase, and not an oxygenase. This was surprising given …

Cationic Metallo-Polyelectrolytes: Synthesis And Application In Self-Assembly And Mechanochemistry, Yujin Cha

Theses and Dissertations

In this dissertation, cationic metallocene-containing polyelectrolytes were investigated for the construction of nano-objects by CDSA and the mechanical force-responsive polymer. The self-assembly behavior and mechanically induced polymer deformation were characterized and discussed.

In Chapter 1, the overall background and recent development of metallocene-containing polymers as well as their applications in self-assembly and polymer mechanochemistry were introduced. Primary research objectives were described.

The first section of the dissertation on the CDSA of cationic metallocene-containing block copolymers was provided in Chapter 2. The preparation of PCL-b-PCoAEMAs was achieved through ring-opening polymerization (ROP) of ε-caprolactone and reversible addition-fragmentation chain-transfer (RAFT) polymerization of cobaltocenium …

Automating And Implementing Complex, Multistep Sample Preparation Processes To Generate Reproducible Proteomic And Phosphoproteomic Data, Brian Todd Mullis

Theses and Dissertations

Phosphorylation is the most common post-translational modification that occurs within the cell and is intricately involved in many biological processes. It is important to understand the roles that protein kinases and phosphatases play by mapping protein phosphorylation as many disease states stem from aberrant signaling events. With the advent of modern mass spectrometry (MS), researchers are now provided with more complex phosphorylation patterns from thousands of proteins in each mass spectrometric analysis. Further developments in quantification techniques, such as stable isotope labeling with amino acids in cell culture (SILAC) and label-free quantitation, have allowed researchers to reliably quantify changes to …