Chemistry Commons^™

Switzerland - Canton Of Uri 1998, University Of Denver

FEAT Heavy-Duty Vehicle Measurements

Relevant Publications

Environmental Science & Technology Publication

Texas - Port Of Houston 2009, University Of Denver

FEAT Heavy-Duty Vehicle Measurements

Relevant Publications

Thesis

Colorado - Coors Brewery, University Of Denver

FEAT Heavy-Duty Vehicle Measurements

Relevant Publications

Environmental Science & Technology Publication (2001)

Environmental Science & Technology Publication (2006)

Thesis

Probing The Surface Acidity Of Supported Aluminum Bromide Catalysts, Md Ashraful Abedin, Swarom Kanitkar, Nitin Kumar, Zi Wang, Kunlun Ding, Graham Hutchings, James J. Spivey

Faculty Publications

Solid acid catalysis is an important class of reactions. The principal advantages of solid acid catalysts as compared to their corresponding fluid acids include minimal waste and ease of product separation. One type of these catalysts is based on aluminum bromide (Al2Br6), which is a stronger Lewis acid than Al2Cl6. In this report, Al(2)Br(6)is grafted on commercial mesoporous silica (CMS), SBA-15 and silica gel to create a solid catalyst similar to the silica-supported Al(2)Cl(6)superacid. These supported Al(2)Br(6)catalysts were characterized by NH3-Temperature Programmed Desorption (TPD), pyridine Diffuse Reflectance for Infrared Fourier Transform Spectroscopy (DRIFTS) and Magic Angle Spinning Nuclear Magnetic Resonance …

Embedded Gold Nanoparticles For Metal Enhanced Photoluminescence, Hasna Alali

Dissertations

Noble metal nanoparticles (MNPs) have attracted great attention in electronics, solar cells and catalysis. Their unique optical properties and biocompatibility makes them useful in biological applications like imaging, drug delivery, therapy and diagnostic. At the surface of MNPs the collective oscillation of free electrons resonates with a particular wavelength of incident light, generating the Localized Surface Plasmons Resonance (LSPR). LSPR results in absorption and scattering of incident light. Scattering results in reflecting photons and absorption leads to enhanced photoluminescence and quenching of fluorophores, if the fluorophore is in the vicinity of MNPs.

Most of the studies in this regard have …

Structural Characterization Of Organic Matter In Oil Shales Using Multiple Nuclear Magnetic Resonance Spectroscopic Techniques, Wenying Chu

Chemistry & Biochemistry Theses & Dissertations

Oil shale is a promising source of hydrocarbon fuel that is distributed throughout the world. The petroleum generating potential of oil shale is related to the molecular structure of the organic matter in source rock. The major fraction of organic matter of oil shale is termed kerogen, and due to its insolubility in organic solvents, ¹³C solid-state nuclear magnetic resonance (NMR) spectroscopy is one of the best ways to directly measure the insoluble organic matter without changing its chemical structures. This dissertation investigated oil shale samples using advanced solid-state ¹³C NMR spectroscopy techniques and high resolution magic angle …

Innovative Approaches In The Discovery Of Aquatic Mycobacteriophages, Janis H. Doss

Biomedical Sciences Theses & Dissertations

Bacteriophages (phages), viruses that infect bacteria, have many applications in medicine, agriculture, molecular biology, and other fields. As antibiotic resistance becomes an increasing problem, interest in phages has grown. The traditional techniques of phage discovery are successful for some phages, but others require modified procedures to achieve detectable host infection.

Mycobacterium is a diverse bacterial genus characterized by a unique cell wall containing mycolic acids, which aids in survival and pathogenesis. The aims of the present research were to isolate mycobacteriophages, use bioinformatics techniques to analyze mycobacterial prophages, and combine genetic analysis with multi-well plate host range studies to identify …

Assessing The Robustness And Versatility Of Nanojars For Anion Binding, Mia Lily Ann Jawor

Masters Theses

Supramolecular chemistry is a field in chemistry that focuses on intermolecular bonds in a “host-guest complex” or supramolecular assemblies. Nanojars are supramolecular assemblies of the formula [anion⊂{Cu(μ-OH)(μ-pz)}_n] (n = 27‒33) which incarcerate kosmotropic anions, such as carbonate (CO₃^2‒), sulfate (SO₄^2‒) and hydrogen phosphate (HPO₄^2‒). Nanojars consist of three [Cu(μ-OH)(μ-pz)]_x (x = 6‒14, except 11) rings that are assembled similarly to Matryoshka dolls, where the top and bottom rings act as guests for the central ring. The larger central ring is bound to the two smaller rings by multiple …

Nanoceria Distribution And Effects Are Mouse-Strain Dependent, Robert A. Yokel, Michael T. Tseng, D. Allan Butterfield, Matthew L. Hancock, Eric A. Grulke, Jason M. Unrine, Arnold J. Stromberg, Alan K. Dozier, Uschi M. Graham

Pharmaceutical Sciences Faculty Publications

Prior studies showed nanoparticle clearance was different in C57BL/6 versus BALB/c mice, strains prone to Th1 and Th2 immune responses, respectively. Objective: Assess nanoceria (cerium oxide, CeO₂ nanoparticle) uptake time course and organ distribution, cellular and oxidative stress, and bioprocessing as a function of mouse strain. Methods: C57BL/6 and BALB/c female mice were i.p. injected with 10 mg/kg nanoceria or vehicle and terminated 0.5 to 24 h later. Organs were collected for cerium analysis; light and electron microscopy with elemental mapping; and protein carbonyl, IL-1β, and caspase-1 determination. Results: Peripheral organ cerium significantly increased, generally more …

Determining The Relative Activities Of Wild-Type Mycobacterium Tuberculosis Indole-3-Glycerol Phosphate Synthase And Mutants E57a And E219a With An Investigation Into The Relationship Between Wild-Type Mycobacterium Tuberculosis Igps Activity And Ph, Thomas Emmanuel Candela

Theses, Dissertations and Culminating Projects

The relationship between wild-type protein indole-3-glycerol phosphate synthase (IGPS) activity and pH was investigated through the formation of pH activity profiles, and the relative catalytic activities of wild-type Mycobacterium tuberculosis and mutants E57A and E219A were also deduced in this work. The activity of each enzyme variant was determined by reacting native substrate 1-(o-carboxyphenylamino)-1-deoxyribulose-5-phosphate with enzyme buffered at pH 7.5 in a cuvette and using a fluorometer to detect the increase in fluorescent signal produced by the formation of fluorescent product indole-3 glycerol phosphate. Work with wild-type IGPS showed the enzyme to have a kcat of 1.26 ± 1.75 (s …

Characterizing Functions Of Two Regulatory Proteins In The Parasitic Nematode Brugia Malayi And Their Potential As Drug Targets In Treating Lymphatic Filariasis, Brittany Amber Hart

Theses, Dissertations and Culminating Projects

Lymphatic filariasis (LF) is a debilitating disease caused by parasitic nematodes that affect millions of people in largely tropical environments. While drugs are available for treating LF, they suffer from a lack of efficacy against adult parasites, toxicity, and emergence of resistance. Here, we describe two novel potential drug targets within the filarial parasite, Brugia malayi (B. malayi). These two proteins, bm9350, a predictive MAPK stress response protein, and bm2032, a potential histone modifying enzyme, have little or no annotation or experimental evidence of function. Using predictive analysis and tools, we examined potential functions of these proteins and their potential …

Studies Toward The Synthesis Of A Novel Diamine Scaffold, Joseph Edward Quinlan Iii

Theses, Dissertations and Culminating Projects

The orexin system in humans contains receptors Orexin 1 (OX1) and Orexin 2 (OX2). These receptors are involved in numerous physiological processes including wake/sleep cycling, energy homeostasis, and motivation/reward. In scientific literature, it is known that antagonism of these receptors exhibits therapeutic effects in the realm of cocaine and alcohol addiction, as well as sleep disorders. On the market today exist drugs for treatment of sleep disorders through orexin receptor antagonization. Here we report a synthesis toward novel conformationally rigid antagonists of the orexin receptor system that may provide improved affinity and/or selectivity compared to known compounds. We report the …

Strategies For Enhancing Chromatographic Efficiencies In Chiral And Achiral Supercritical And Liquid Chromatography, Daipayan Roy

Chemistry & Biochemistry Dissertations - Archive

The fundamental aim of chromatography has been to achieve baseline separation between the components of a mixture in the shortest possible time. Recently there has been a shift in the chromatographic focus of enantiomeric separations, with an emphasis on increasing the efficiency of columns. Superficially porous particles (SPP) introduced about a decade ago lead to a surge in efficiency as compared to the traditionally used fully porous particles (FPP). Recently chiral selectors bonded to superficially porous particles have been commercialized. This work reports new methods for enantioseparation using chiral selectors like macrocyclic glycopeptides, modified cyclodextrins and cyclofructans bonded to SPPs. …

Graphite Intercalation Compounds Derived By Green Chemistry As Oxygen Reduction Reaction Catalysts, Jianchao Zhao, Joseph H. Dumont, Ulises Martinez, Javier Macossay-Torres, Kateryna Artyushkova, Plamen Atanassov, Gautam Gupta

Physics & Astronomy Faculty Publications

Precious group metal (PGM) catalysts such as Pt supported on carbon supports are expensive catalysts utilized for the oxygen reduction reaction (ORR) due to their unmatched catalytic activity and durability. As an alternative, PGM-free ORR electrocatalysts that offer respectable catalytic activity are being pursued. Most of the notable PGM-free catalysts are obtained either from a bottom-up approach synthesis utilizing nitrogen-rich polymers as building blocks, or from a top down approach, where nitrogen and metal moieties are incorporated to carbonaceous matrixes. The systematic understanding of the origin of catalytic activity for either case is speculative and currently employed synthesis techniques typically …

The Legacy Of Mining In Southwest Missouri: Past And Present Conditions Of The Tri-State Mining District, Anastasia M C Mcclanahan

Graduate Theses/Dissertations

The historic Tri-State Mining District (TSMD) of southwestern Missouri, southeastern Kansas, and northeastern Oklahoma has a history of lead and zinc mining that extended over a hundred years. During the district’s peak production period, the TSMD was one of the world’s largest producers of lead and zinc. The mining activities in the TSMD produced economic growth that supported the local communities and were essential to the victory of the Allied Forces during World War I and World War II. Beginning in the 1920s, the mining activities in the district slowly began to cease due to depletion of metal ores and …

Freshwater Endmembers Impacting Carbonate Chemistry In The Mississippi Sound, Allison Savoie

Master's Theses

Coastal ecosystems are highly dynamic areas for carbon cycling and are likely to be negatively impacted by increasing ocean acidification. This research focused on dissolved inorganic carbon (DIC) and total alkalinity (TA) in the Mississippi Sound in order to understand the influence of local rivers that supply alkalinity to the area and buffer against ocean acidification. This area receives large fluxes of freshwater from local rivers, in addition to episodic inputs from the Mississippi River through a human-built diversion, the Bonnet Carré Spillway. Sites in the Mississippi Sound were sampled monthly during August 2018 to November 2019 and at weekly …

Application Of Carbon Nanoparticles As Dna Detection Probe And Fluorescent Ink, Luckio Frank Owuocha

Graduate Theses/Dissertations

There is a significant interest in developing a sensitive, selective, efficient, and inexpensive method for rapid molecular diagnostic tests. This research aims to develop an inexpensive nucleic acid detection method by using DNA-conjugated carbon nanoparticles that exhibit fluorescence in the visible region. Carbon nanoparticles of this class can be detected without specialized equipment and have great promise toward the development of analytical methods that can be used in resource-limited environments with a lack of access to proper diagnostic and healthcare. We employed EDC-NHS (two-step) and EDC (one-step) coupling techniques to prepare DNA-conjugated carbon nanoparticles. The dot blotting method was adapted …

Doping Effects On Transition-Metal Silicides: Crystal Structures And Physical Properties Of Aluminium Doped Rhenium Silicide, Victoria Decocq

Graduate Theses/Dissertations

Semiconductive transition-metal silicides (e.g., ReSi) express weak thermoelectric properties. These properties can improve through n-type or p-type doping (e.g., Al), resulting in altered crystal structures. Binary rhenium silicide (ReSi_1.75) exhibits promising thermoelectric properties and an intriguing crystal structure. Previous research has shown ReSi_1.75 changes from a commensurate supercell MoSi₂-type structure to an incommensurate superspace group structure, when doped with aluminium to ReAl_0.074Si_1.67. ReSi_1.75 expresses a figure of merit (ZT) of 0.70 at 800°C, which improves to a ZT of 0.95 at 150°C for ReAl_0.02Si_1.75. Because of …

A Simple Predictive Model For Estimating Relative E-Cigarette Toxic Carbonyl Levels, Shawna Vreeke, Xijing Zhu, Robert Strongin

Chemistry Faculty Publications and Presentations

E-cigarette devices are wide ranging, leading to significant differences in levels of toxic carbonyls in their respective aerosols. Power can be a useful method in predicting relative toxin concentrations within the same device, but does not correlate well to inter-device levels. Herein, we have developed a simple mathematical model utilizing parameters of an e-cigarette’s coil and wick in order to predict relative levels of e-liquid solvent degradation. Model 1, which is coil length/(wick surface area*wraps), performed in the moderate-to-substantial range as a predictive tool (R² = 0.69). Twelve devices, spanning a range of coil and wick styles, were analyzed. …

Synthesis, Characterization, And Biological Studies Of Novel Organoantimony(V) Cyanoximates, Kevin Anthony Pinks

Graduate Theses/Dissertations

The requirement of new antimicrobial treatments has become an urgent field recently. Multi-drug resistant (MDR) bacteria are now resistant to common antibiotics. To antagonize such bacteria 8 novel organoantimony(V) cyanoximates were synthesized to be characterized and submitted for biological activity studies. Eight organoantimony(V) cyanoximates were characterized by elemental analysis, thermal analysis, IR-, ¹³C{¹H} NMR, some with UV-visible spectroscopy, and single crystal X-ray analysis. Antimicrobial Disk studies indicated Sb(Ph)₄(ACO) and Sb(Ph)₄(ECO) had significant antimicrobial effect against all three strains: two gram-negative a) Escherichia coli strain S17 and b) Pseudomonas aeruginosa strain PAO1, alongside a …

Characterization Of An Acid Rock Drainage Microbiome And Transcriptome At The Ely Copper Mine Superfund Site, Lesley Ann Giddings, George Chlipala, Kevin Kunstman, Stefan Green, Katherine Morillo, Kieran Bhave, Holly Peterson, Heather Driscoll, Mark Maienschein-Cline

Chemistry: Faculty Publications

The microbial oxidation of metal sulfides plays a major role in the formation of acid rock drainage (ARD). We aimed to broadly characterize the ARD at Ely Brook, which drains the Ely Copper Mine Superfund site in Vermont, USA, using metagenomics and metatranscriptomics to assess the metabolic potential and seasonal ecological roles of microorganisms in water and sediment. Using Centrifuge against the NCBI “nt” database, ~25% of reads in sediment and water samples were classified as acid-tolerant Proteobacteria (61 ± 4%) belonging to the genera Pseudomonas (2.6-3.3%), Bradyrhizobium (1.7-4.1%), and Streptomyces (2.9-5.0%). Numerous genes (12%) were differentially expressed between seasons …

Water Cluster Motifs In Structurally Similar N-(2-Aminoethyl)-1-Methylimidazole-2-Carboxamide Metal Complexes: Synthesis, Characterization, Thermal And Electrical Properties., Nina Saraei

Electronic Theses and Dissertations

Water is a remarkable molecule and in all of its forms exhibits an amazing collection of properties and functions. Besides its crucial role in life and many technological processes, water displays some unusual and anomalous properties at various interfaces and under different conditions. Although the role of hydrogen-bonding interactions and their fluctuations are well known to determine the properties of water, the main obstacle exists in the complexity of correctly describing the interactions between water molecules. The key to understanding the behavior of water is to collect precise structural data of various H-bonded water networks in diverse environments. In this …

(Pseudo)Phase Tuning In The Service Of Synthesis: Technologies For Sustainable Catalysis., Justin Douglas Smith

Electronic Theses and Dissertations

Strategies for manipulation of chemical phases were explored with emphasis on synthetic chemistry applications. Some strategies are fairly divergent from their origin, but all ultimately began from investigations of micellar media. Accordingly, Chapter 1 reviews the historical development of micellar catalytic processes. Chapters 2 and 3 detail development of synthetic methods in micellar solutions of designer surfactant PS-750-M. PS-750-M was designed to create benign micellar solutions which effectively mimic toxic organic solvents; it contains a proline-based linker between its hydrophobic and hydrophilic regions which imparts increased polarity to the micellar core. Chapter 2 details an interfacial nucleophilic substitution of perfluoroarenes …

Unbinding Of Testosterone From The Androgen Receptor And Two Bf-3 Site Mutants, Muniruzzaman Chowdhury

Theses and Dissertations

The androgen receptor (AR) can be activated by molecules binding in the steroid binding pocket. It can also be regulated allosterically by cofactors binding to the AF-2 surface site as well as by exogenous small molecules binding to the BF-3 surface site. Recent data indicated that mutations in the BF-3 site changed the amount of the endogenous steroid needed to activate the receptor, indicating that mutations of BF-3 can cause an allosteric effect. Molecular dynamics and steered molecular dynamics simulations were used to study the allosteric effect of the mutations on AR structure and the unbinding pathways of testosterone (TES) …

Nonwovens Of Ceramic Decorated Cellulose Based Fine Fibers For Leaded Water Purification, Alejandro J. Castillo

Theses and Dissertations

Fine fibers of cellulose acetate were Forcespun and used to make nonwoven mats of cellulose. Nonwovens were activated using a solution combustion synthesis which deposited iron nitride onto fibers. Cellulose and cellulose composite mats were tested as adsorbents for lead ion in water. Cellulose showed slightly higher adsorption capacities (mg/g) up to 1300 mg/g lead loading. Adsorption data were further analyzed using several isotherms, of which the Dubinin-Raduskevich gave the best fits.

Synthesis And Characterization Of Bimetallic Gold-Silver (Au-Ag) Nanocatalyst Via Seed Colloid Technique, Berahim Nurafaliana

Student Works (2020-2029)

In the present study, unique catalysts of monometallic gold (Au), silver (Ag) and bimetallic gold-silver (Au-Ag) nanoparticles (NPs) were prepared with different size or diameters by the citrate-thermal reduction and the seed colloidal techniques, respectively. The catalytic nanoparticles were characterized by various advanced analytical techniques such as Ultraviolet-visible spectroscopy (UV-vis), zeta potential, electron dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), High-angle annular dark-field (HAADF) scanning transmission-electron microscopy (STEM) imaging and the energy dispersive spectroscopy (EDS) elemental mapping. The catalytic performance of the nanoparticles were ascertained through the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in …

Synthesis And Characterization Of Self-Cleaning Hydrophobic Organic Coating, Abdul Jaafar Amirul Syafiq

Student Works (2020-2029)

Three self-cleaning coating systems namely Polydimethylsiloxane (PDMS)/Sylgard, PDMS/3-Aminopropyltriethoxysilane (APTES) (tagged as A1) and A1 blended with nano-Calcium Carbonate (CaCO3) have been synthesised on glass substrates via dip-coating and spray-coating techniques. All of the prepared coatings were dried under ambient condition before being subjected to characterisations and testing(s). The effect of various weight percentages of Sylgard resin that are 5wt.% (S1 coating), 10wt.% (S2 coating), 15wt.% (S3 coating), and 20 wt.% (S4 coating) on the hydrophobicity, self-cleaning property, anti-fog performance and mechanical property of PDMS/Sylgard coating have been discussed in the first section of this thesis. The PDMS/Sylgard coated glass substrates …

Synthesis Of Polyaniline Modified With Palm Oil Based Alkyd As Counter Electrode In Solar Cell Application, Ramli Mariam Fadzlina

Student Works (2020-2029)

Presently, shortage of sustainable and environmental friendly energy resources has become an important global concern. Dye-sensitized solar cell (DSSC) has widely been used as a clean energy conversion device that can solve this problem. Platinum (Pt) has commonly been used as counter electrode (CE) in DSSC due to its good redox property. However, Pt is expensive and could be easily corroded in tri-iodide solution. Recently, polyaniline (PAni) has shown promising performance in DSSC, but PAni exhibit poor adhesion on fluorine-doped tin oxide (FTO) substrate. In this study, an environmental friendly CE was developed by modifying PAni using titanium dioxide (TiO2) …

Synthesis And Biological Activities Of Imidazolium Acridines And Their Silver Complexes, H S Sharhan Olla

Student Works (2020-2029)

In the present study, a series of acridine-based imidazolium ligands were synthesized by the Menshutkin reaction and used for the preparation of the silver complexes. The structures were established using NMR and IR spectroscopy as well as high-resolution mass spectrometry. The purity of the ligands was confirmed by CHN elemental analysis, while energy-dispersive X-ray spectroscopy (EDX) was applied for the silver complexes. In view of the luminescent behaviour of acridine, UV-Vis and fluorescence spectra were recorded for ligands and complexes. However, low water solubility constrains potential application as analytical probe. Preliminary in vitro cytotoxicity screenings were performed using an MTT …

Microstructural Evolution And Mechanical Properties Of Ultra-Fine Grained Tubular Components Processed By Severe Plastic Deformation, Mesbah Mohsen

Student Works (2020-2029)

The lightweight alloys have been widely used in various engineering applications such as automotive, aerospace, construction, and biomedical industries due to their low densities, high ductility, formability, and facile machining. However, the emerging trend for materials with high mechanical strength and plasticity hampers the widespread application of these alloys. Over the last two decades, severe plastic deformation (SPD) has been introduced as a promising approach for enhancement of the mechanical performance of the lightweight alloys through microstructural manipulations and grain refinement. However, the SPD techniques have been extensively utilized for the fabrication of non-tubular geometries and the studies on the …