Chemistry Commons^™

Molecular Encapsulation In Kinetically Trapped, Hydrogen-Bonded Pyrogallolarene Hexamers, Jennifer Christine Chapin Lake

Electronic Theses and Dissertations

Pyrogallolarene and resorcinarene hexamers are hydrogen-bonded capsules that self-assemble in the solid state and can be studied in gaseous and solution phases. Guest loading within pyrogallolarene hexamers in solution has primarily been comprised of solvent molecules with some tertiary amines. A novel solvent-free method for loading guests into the interior of the hexamer has been shown to be effective for encapsulation of a variety of molecules. Aromatic and aliphatic compounds have particularly high guest loading within the hexamers and often result in kinetically stable guest-filled capsules in solution.

Kinetic studies of the encapsulation complexes of anthracene, biphenyl, fluoranthene, fluorene, naphthalene, …

Nitroxide Radicals For Low Frequency Electron Paramagnetic Resonance Imaging (Epri), Joshua R. Biller

Electronic Theses and Dissertations

Optimization of nitroxides as probes for EPR imaging requires detailed understanding of spectral properties such as spin lattice relaxation times, spin packet linewidths, and nuclear hyperfine splitting. Initial measurements of relaxation times for six low molecular weight nitroxides at X-band stimulated further measurement at frequencies between 250 MHz and 34 GHz. The impact of tumbling was studied with perdeuterated 2,2,6,6-tetramethyl-4-piperidinyl-1-oxyl (PDT) in five solvents with viscosities resulting in tumbling correlation times, τ_R, between 4 and 50 ps. A set of three ¹⁴N/¹⁵N pairs of nitroxides in water was selected such that τ_R varied between …

Photoassisted Access To New Polyheterocycles, Teresa M. Cowger

Electronic Theses and Dissertations

Photoassisted diversity-oriented synthesis holds great promise in its ability to provide rapid access to complex and diverse molecular scaffolds. As it stands, while photochemical techniques have this potential, their implementation in the field of synthetic organic chemistry is very limited. The main goal of this project was to utilize photochemically assisted techniques in the synthesis of a variety of novel polyheterocycles.

Initially, we explored the how the strain installed in these polycycles could be harnessed to trigger cationic rearrangements in the framework of the system. This was achieved via the high yield and rapid assembly of a highly strained system …

Probing Structure For Photophysical Properties Through Synthesis Of Novel Nucleosides, Brittney Jean Rodgers

Electronic Theses and Dissertations

A brief history of nucleosides and their photophysics provides the background information for the discussion of synthesis, photophysics and incorporation of fluorescent nucleotide analogs during enzymatic DNA synthesis. Through the use of nucleoside starting material, it is possible to synthesize a number of modified nucleotides for use as fluorescent probes in biochemical research. Synthetic endeavors into the synthesis of these and related molecules from nucleobase starting materials are also presented. The synthesis of these molecules involved re-development of the synthetic routes to broaden substrate scope by overcoming the changed reactivity resulting from the presence of additional functionality.

While many highly …

Development Of A Biosensor For Investigating Membrane Curvature Sorting, Joshua C. Black

Electronic Theses and Dissertations

The physical structure of cellular membranes plays a critical role in lipid and protein sorting. A novel biosensor was developed to probe the influence of curvature on sorting. This biosensor mimics large, two-dimensional membranes in dynamic equilibrium, achieves high spatial resolution between curvature and molecules of interest, and has high sensitivity, enough for single particle detection. The biosensor consists of continuous supported lipid bilayer formed over nanoparticles (40 to 200 nm diameter) deposited on a glass substrate. The nanoparticles determine the extent of curvature. This biosensor is the first to observe large-scale 2-dimensional diffusion of biomolecules on a supported lipid …

X-Band Rapid-Scan Epr, Deborah Gale Mitchell

Electronic Theses and Dissertations

The advantages of rapid-scan EPR relative to CW and pulse techniques for samples with long longitudinal relaxation time T₁ (N_s⁰ defects in diamond, N@C₆₀, and amorphous hydrogenated silicon), heterogeneous samples (crystalline 1:1 α,γ-bisdiphenylene-β-phenylallyl (BDPA):benzene), lossy samples (aqueous nitroxyl radicals), and transient radicals (5-tert-butoxycarbonyl-5-methyl-1-pyrroline-N-oxide (BMPO)-superoxide adduct) were studied.

For samples with long relaxation times, CW (continuous wave) EPR is challenging due to power saturation and distortions from passage effects. In rapid-scan EPR, the field is swept through resonance in a time that is short relative to T₂. In rapid-scan EPR, the magnetic field is …

Seeded Propagation Of Tau Fibrils, Paul David Dinkel

Electronic Theses and Dissertations

In various neurodegenerative diseases, including Alzheimer's disease, progressive supranuclear palsy, Pick's disease, and corticobasal degeneration, the deposition of fibrils composed of misfolded tau protein is observed. Recent evidence suggests that tau fibrils transfer between cells and spread throughout the brain, underscoring the significance of fibril propagation.

Six tau isoforms exist in the adult human brain that can be grouped into 4-repeat (4R) tau and 3-repeat (3R) tau based on the presence or absence of the second of four microtubule binding repeats. We demonstrate in vitro that seeded fibril growth, a prerequisite for the spreading of the tau pathology, is crucially …

Design And Synthesis Of Novel Fluorescent Nucleoside Analogues, Nada Abdulnasir Elsharif

Electronic Theses and Dissertations

This project aimed to obtain a set of fluorescent nucleoside analogues that closely resemble cytosine with extending the aromatic surface (extended conjugation) for enhance the photophysical properties. In addition to synthesize new fluorescent nucleoside analogues and evaluate their photophysical properties, this project aimed to understand the effects of donor substituent on the tC photophysical properties.

The main goal of these studies is to develop highly fluorescent nucleotide analogues. We first were looking to synthesize tC^C fluorescent nucleotide with the pyrimido[4,5-b]quinolone. In this part, 2-chloro-3- formylquinoline was easily prepared, yet the cyclization of 2-chloro-3- formylquinoline with urea or guanidine HCl …

Trends In Heavy-Duty Diesel Emissions And Analyses Of Colorado's Light-Duty Vehicle Inspection And Maintenance Program, Brent G. Schuchmann

Electronic Theses and Dissertations

Emission trends are reported and discussed resulting from the multi-year study of Heavy-Duty Diesel Vehicles (HDDV) at the Port of Los Angeles and at a weigh station in Peralta also in the L.A. basin. Remote sensing data were also collected from the Port of Houston and compared to the data from California. As part of San Pedro Bay Ports Clean Air Action Plan (CAAP) to fast track the turnover rate of cleaner trucks, many truck operators have been subject to modifying their trucks, or have purchased new trucks, with more advanced control technologies to reduce exhaust particulate matter (PM) and …

Particle Matter Measurements For Inspection/Maintenance Programs, Daniel Joseph Pope

Electronic Theses and Dissertations

Particle emissions from Heavy Duty Diesel Vehicles (HDDVs) are currently measured by opacity or dynamometer gravimetric analysis. The Electronic Tailpipe Particle Sensor (ETaPS) is an inexpensive measurement device purported to give real time response to particle mass and was proposed as a possible addition to Inspection/Maintenance (I/M) programs. There were three goals to this study. The first was to verify ETaPS response to particle mass of HDDV exhaust. Integrated ETaPS signal was plotted against filter weight from dynamometer gravimetric analysis and a correlation was found. The second goal was to find a correlation between ETaPS readings and the Remote Sensing …

Analysis And Treatment Of Emerging Polar Contaminants, Daniel E. Connors

Electronic Theses and Dissertations

Two major classes of polar compounds have recently become a major focus as sources of contamination of water systems. Pharmaceuticals and personal care products (PPCPs) enter water through wastewater streams, and many of these compounds survive current wastewater treatment processes. High production volume chemicals (HPVCs), defined as chemicals produced in excess of one million pounds per year have numerous entries into surface and drinking waters due to their ubiquity. The commonality between many of these compounds is their polarity, which makes them water-soluble.

While both PPCPs and HPVCs have been entering into the environment for decades, advances in analyte detection …

On-Road Remote Sensing Of Automobile Emissions In The Phoenix Area: Year 4, November 2002, Gary A. Bishop, Daniel A. Burgard, Mitchell J. Williams, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

On-Road Remote Sensing Of Automobile Emissions In The Chicago Area: Year 5, September 2002, Gary A. Bishop, Mitchell J. Williams, Daniel A. Burgard, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

On-Road Remote Sensing Of Automobile Emissions In The Denver Area: Year 4, January 2003, Daniel A. Burgard, Gary A. Bishop, Mitchell J. Williams, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

On-Road Remote Sensing Of Automobile Emissions In The Labrea Area: Year 2, Mitchell J. Williams, Gary A. Bishop, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

Feat Monochromator User's Guide, Gary A. Bishop

Fuel Efficiency Automobile Test Publications

No abstract provided.

A Five-Channel, Single Detector, Emission Remote Sensor (Presentation), Mitchell J. Williams, Donald H. Stedman, Gary A. Bishop, Richard W. Quine

Fuel Efficiency Automobile Test Publications

No abstract provided.

Fuel Efficiency Automobile Test Standard Operating Procedures, Donald H. Stedman, Gary A. Bishop

Fuel Efficiency Automobile Test Publications

No abstract provided.

On-Road Emissions Of Motor Vehicles In Brazil: Current Status And Future Possibilities (Presentation), Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

On-Road Remote Sensing Of Automobile Emissions In The Los Angeles Area: Year 3 (Riverside), Sajal S. Pokharel, Gary A. Bishop, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

The University of Denver conducted the third year of a multi-year remote sensing study in the Los Angeles, CA area. The remote sensor used in this study is capable of measuring the ratios of CO, HC, and NO to CO2 in motor vehicle exhaust. From these ratios, we calculate the percent concentrations of CO, CO2, HC and NO in motor vehicle exhaust which would be observed by a tailpipe probe, corrected for water and any excess oxygen not involved in combustion. The system used in this study was also configured to determine the speed and acceleration of the vehicle, and …

On-Road Remote Sensing Of Automobile Emissions In The Phoenix Area: Year 3, Sajal S. Pokharel, Gary A. Bishop, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

The University of Denver conducted a five-day remote sensing study in the Phoenix, AZ area in the fall of 2000. The remote sensor used in this study is capable of measuring the ratios of CO, HC, and NO to CO2 in motor vehicle exhaust. From these ratios, we calculate mass emissions per kg (or gallon) of fuel and the percent concentrations of CO, CO2, HC and NO in motor vehicle exhaust which would be observed by a tailpipe probe, corrected for water and any excess oxygen not involved in combustion. The system used in this study was also configured to …

Opacity Enhancement Of The On-Road Remote Sensor For Hc, Co And No, Donald H. Stedman, Gary A. Bishop

Fuel Efficiency Automobile Test Publications

No abstract provided.

Remote Sensing: A New Tool For Automobile Inspection And Maintenance, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

Federally-mandated emissions testing of automobiles in Colorado has decreased emissions, albeit much less than predicted. Recent breakthroughs in manufacturing low emitting vehicles and in remote sensing of a moving car’s exhaust could enable Colorado to phase out or drastically increase the efficiency of treadmill-style testing centers. Remote sensing technology now allows a piece of equipment small enough to fit in a van to assess the mass of pollutants per gallon of fuel emitted by a passing car. Once an emissions scofflaw is identified, a number of options exist:

· immediate pullover and ticketing by a police officer;

· a “smart …

On-Road Remote Sensing Of Automobile Emissions In The Denver Area: Year 3, Sajal S. Pokharel, Gary A. Bishop, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

Interpreting Remote Sensing Nox Measurements (Presentation), Robert Slott, Donald H. Stedman, Sajal S. Pokharel

Fuel Efficiency Automobile Test Publications

No abstract provided.

On-Road Remote Sensing Of Automobile Emissions In The Chicago Area: Year 4, Sajal S. Pokharel, Gary A. Bishop, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

The University of Denver has completed the first four years of a multi-year remote sensing study in the Chicago area. The remote sensor used in this study is capable of measuring the ratios of CO, HC, and NO to CO2 in motor vehicle exhaust. From these ratios, we calculate the percent concentrations of CO, CO2, HC and NO in the exhaust that would be observed by a tailpipe probe, corrected for water and any excess oxygen not involved in combustion. Mass emissions per mass or volume of fuel can also be determined. The system used in this study was configured …

Preliminary Studies Using Remote Sensing To Evaluate I/M Effectiveness, Sajal S. Pokharel, Gary A. Bishop, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

On-Road Motor Vehicle Emissions Measurements Worldwide (Presentation), Sajal S. Pokharel, Gary A. Bishop, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

Motorcycle Emissions System (Presentation), Donald H. Stedman

Fuel Efficiency Automobile Test Publications

Multireflection optics for noncontact measurement of small emissions plumes

Fuel-Based On-Road Motor Vehicle Emissions Inventory For The Denver Metropolitan Area, Sajal S. Pokharel, Gary A. Bishop, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

Emission inventories from mobile sources have traditionally been obtained through computer modeling. This method, however, has intrinsic shortcomings in that ideal factors are included while real-world observations are left out. The model predictions have not correlated well with measurements from several studies. Recently, a fuel-based method of obtaining on-road emissions inventories has been developed. This technique calculates emission factors in grams of pollutant per unit of fuel used (kg, gallons or L) from remote sensing measurements. Combining these factors with fuel use data, available from tax records, yields a fuel based emission inventory. We have used this routine to calculate …