Physical Chemistry Commons^™

The Transsulfuration Pathway Significantly Contributes To Glutathione Biosynthesis In Human Mammary Epithelial Cells, Andrea Del Pilar Belalcazar Maya

Theses, Dissertations and Capstones

Cellular methylation and antioxidant metabolism are linked by the transsulfuration pathway, which converts the methionine cycle intermediate homocysteine to cysteine, a precursor for glutathione biosynthesis, principally in hepatic cells. In mammals, the transsulfuration pathway has been identified in liver, kidney, pancreas and brain. To determine whether the pathway exists in mammary cells human breast adenocarcinoma cells (MCF-7) and normal mammary epithelial cells (HMEC) were labeled with ³⁵S-methionine for 24 hours following pre-treatment with a vehicle control, the cysteine biosynthesis inhibitor propargylglycine (PPG) or the gammaglutamyl cysteine synthesis inhibitor buthionine sulfoximine (BSO). Cell lysates were prepared and reacted with glutathione-S-transferase …

Triatomic Molecular Orbitals, Carl W. David

Chemistry Education Materials

If elementary Quantum Chemistry stops at diatomic molecules, some students may be left with false impressions concerning how one builds polyatomic molecule's LCAO-MOs. This reading discusses building such molecular orbitals from atomic orbitals centered at different spatial coordinates.

Continued Fraction Solutions To Hermite's, Legendre's And Laguerre's Differential Equation, Carl W. David

Chemistry Education Materials

The continued fraction method for solving differential equations is illustrated using three famous differential equations used in quantum chemistry.

More Than You Ever Cared To Know About Solution Thermodynamics, Carl W. David

Chemistry Education Materials

These readings are a compendium of earlier works put together and corrected for errors. The subject is solution thermodynamics, based on the one dimensional binary solution as "extended" to three dimensions.

The Investigation Of Epr Paramagnetic Probe Line Width And Shape Temperature Dependence In High-Temperature Superconductors Of Bi–Pb–Sr–Ca–Cu–O System, J. G. Chigvinadze, Juana Vivó Acrivos, I. G. Akhvlediani, M. I. Chubabria, T. L. Kalabegishvili, T. I. Sanadze

Faculty Publications, Chemistry

The work is related with the finding out of magnetic phases in strongly anisotropic high-temperature superconductor Bi1,7Pb0,3Sr2Ca2Cu3O10-δ in the temperature region where the superconductor is in the normal state. It was studied the temperature dependence of the paramagnetic probe EPR line width. In the normal state at T>Tc near 175 K it was revealed a pick in the temperature dependence of line width. In this region it was observed the time increase of the line width with the characteristic time ~ 17 min. This shows the possibility of magnetic phase formation in this material.

One-Pot Synthesis Of Anionic (Nitrogen) And Cationic (Sulfur) Codoped High-Temperature Stable, Visible Light Active, Anatase Photocatalysts, Suresh Pillai, Declan Mccormack, Steven Hinder, Pradeepan Periyat

Articles

No abstract provided.

Carnot Cycles: Traditional And Stefan Boltzmann, And The First Planck Argument, Carl W. David

Chemistry Education Materials

The Stefan Boltzmann equation is obtained using a non-traditional Carnot Engine. In addition, the original Planck argument for radiation density is given.

Lee O. Case's "Elements Of The Phase Rule", Chapter 1, One Component Systems, Carl W. David

Chemistry Education Materials

One component systems are treated from the point of view of the Gibbs' phase rule.

Lee O Case's "Elements Of The Phase Rule", Chapter 3, Carl W. David

Chemistry Education Materials

This is the last (third) chapter of the phase rule text, again altered by the author, addressing 3 and 4 compnent systems.

Nanofiltration Membrane Pilot Studies For Disinfection By-Product Control, Eric J. Lynne

Electronic Theses and Dissertations

Watertown, South Dakota currently uses conventional softening to treat ground water to remove hardness, iron and manganese, and natural organic matter. The distribution system has experienced elevated concentrations of disinfection by-products, which will require additional treatment to comply with future limits set by the Stage 2 Disinfectant/Disinfection By-Products Rule. A nanofiltration membrane system has been proposed to remove additional natural organic matter from the softened water. Removing the natural organic material disinfection by-product precursors should reduce the concentration of disinfection by-products. The use of nanofiltration membranes has been previously documented to reject total organic carbon, while allowing desirable levels of …

Physical Properties Of Cytochromes C : 1. Role Of Cytochrome C' As A Nitric Oxide Carrier, 2. Folding Of Cytochrome C, Byunghoon Lee

Legacy Theses & Dissertations (2009 - 2024)

Cytochrome c’ binds and transfers endogenous NO in the denitrifying variant of Rhodobacter sphaeroides 2.4.3 and the NO bound ferrous heme that forms 5-coordinate resembles regulatory site in soluble guanylate cyclase. The Arg127 is close to the 5-coordiate NO bound heme of the cytochrome c’. The mutant (R127A) that was overexpressed in a cytochrome c’ knock-out R. sphaeroides 2.4.3 provided the opportunity to research the functional role of Arg127 in the redox potential and NO binding. The mutant (R127A) showed lower redox potential and lower NO binding free energy than wild type. ERP and ENDOR showed that the mutant had …

Bowl-Shaped Polyaromatic Hydrocarbons (Buckybowls) : Crystal Packing And Metal Binding Reactions, Alexander S. Filatov

Legacy Theses & Dissertations (2009 - 2024)

This work is a part of a broad program in our laboratory dedicated to the investigation of a new class of non-planar polyaromatic hydrocarbons that map onto the surfaces of fullerenes (and referred to as buckybowls). It focuses on the preparation of buckybowls, their molecular and solid state structures, and reactivity in metal binding reactions. For the first time, the structures of all available buckybowls have been analyzed using X-ray diffraction data collected in the course of this work, as well as data previously obtained in our group or reported by others (and dearchived from the Cambridge Structural Database). Forces …

Nanocomposite Thin Films Of Au Nanoparticles Embedded In Yttria-Stabilized Zirconia For Plasmonic-Based Harsh Environment Gas Detection, Phillip Henry Rogers

Legacy Theses & Dissertations (2009 - 2024)

Increased health concerns due to the emission of gases linked to the production of tropospheric ozone by petroleum based fuel burning engines has resulted in the codification of more stringent emissions regulations domestically. Emissions regulations on commercial jetliners are one of the areas to be met with stricter standards. Currently there is not a sensing technology that can detect the emissions gases in the exhaust stream of a jet turbine engine with lower detection limits that meet these standards.

Preparation And Characterization Of Some Substituted Benzyl N-Nitrosocarbamates Containing An N-2-(Methylthio)Ethyl Or A Bis(2-Aminoethyl)Sulfide Functionality, Satya Venkata, Eric Shamo, Vladimir Benin

Chemistry Faculty Publications

The synthesis and characterization of some substituted benzyl N-nitrosocarbamates with an N-2-(methylthio)ethyl or a bis(2-aminoethyl)sulfide functionality is reported, as a part of a long-term goal to design and prepare novel photolabile structures that could be used as substances for controlled release of alkylating and/or crosslinking agents. The synthesis was accomplished by reaction of benzyl chloroformates with the corresponding amines, resulting in the preparation of carbamates. The latter were subsequently nitrosated, utilizing two different N-nitrosation methods, to yield the target structures.

One-Pot Synthesis Of Anionic (Nitrogen) And Cationic (Sulfur) Codoped High-Temperature Stable, Visible Light Active, Anatase Photocatalysts, Suresh Pillai, Declan Mccormack, Steven Hinder, Pradeepan Periyat

Articles

No abstract provided.

Partial Ion Yield Sspectroscopy Around The Cl 2p And C 1s Ionization Thresholds In Cf3cl, D. Ceolin, Maria Novella Piancastelli, Wayne C. Stolte, Dennis W. Lindle

Chemistry and Biochemistry Faculty Research

We present a partial ion yield experiment on freon 13, CF₃Cl, excited in the vicinity of the C 1s and Cl 2p ionization thresholds. We have collected a large amount of cationic fragments and a few anionic fragments at both edges. We have observed a strong intensity dependence of Rydberg transitions with ion fragment size for the CF_nCl⁺ and CF_n⁺/F⁺ (n=0–3) series at both the Cl 2p and C 1s ionization edges. Selectivity in the fragmentation processes involving the C–Cl and C–F bonds are highlighted by the intensities of the C …

Yttrium And Hydrogen Superstructure And Correlation Of Lattice Expansion And Proton Conductivity In The Bazr0.9y0.1o2.95 Proton Conductor, A. Braun, A. Ovalle, V. Pomjakushin, A. Cervellino, S. Erat, Wayne C. Stolte, T. Graule

Chemistry and Biochemistry Faculty Research

Bragg reflections in Y-resonant x-ray diffractograms of BaZr_0.9Y_0.1O_2.95 (BZY10) reveal that Y is organized in a superstructure. Comparison with neutron diffraction superstructure reflections in protonated/deuterated BZY10 suggests that both superstructures are linked, and that protons move in the landscape imposed by the Y. The thermal lattice expansion decreases abruptly for protonated BZY10 at T≥648±20 K, coinciding with the onset of lateral proton diffusion and suggesting a correlation of structural changes and proton conductivity. The chemical shift in the Y L₁-shell x-ray absorption spectra reveals a reduction from Y³⁺ toward Y²⁺ upon …

Pressure Induced Phase Transformation Of Sno2: An Ab Initio Constant Pressure Study, Daniel Tesfai Yehdego

Open Access Theses & Dissertations

The behavior of SnO2 under rapid hydrostatic pressures is studied using constant-pressure ab initio simulations. The rutile-type SnO2 gradually transforms into the CaCl2-type structure at 15 GPa. At a pressure of about 20 GPa, a phase transformation into a cubic fluorite-type structure is observed. The orthorhombic Pnma cotunnite-structured phase is observed above 150 GPa. The mechanisms of these phase transformations at the atomistic level are discussed.

Spectroscopic Investigation Of Palladium-Copper Bimetallic Systems For Pem Fuel Cell Catalysts, Timo Hofmann

UNLV Theses, Dissertations, Professional Papers, and Capstones

One of the main barriers to commercialization of polymer electrolyte membrane fuel cells systems is cost, which is largely due to the need of platinum (Pt)-containing catalysts. In this thesis we investigate bimetallic systems consisting of a base metal (copper) and a noble metal (palladium) that, as an alloy on the nanoscale, mimic the electronic properties that make Pt desirable as a catalyst.

We present a detailed investigation of the electronic structure of carbon-supported Pd/Cu nanoparticle catalysts, model bilayer thin film systems, alloys, and various metal reference samples. We have investigated the valence band structure of the catalysts using a …

Characterization Of Iron Oxide Thin Films For Photoelectrochemical Hydrogen Production, Kyle Eustace Nelson George

UNLV Theses, Dissertations, Professional Papers, and Capstones

Solar energy is the most sustainable source of energy available. However, solar applications such as photovoltaic cells represent only a partial solution to weaning our dependence upon fossil fuels. Several methods of storing solar energy are currently being pursued, and chemical storage stands out as a promising option - combining design simplicity with high energy density, with hydrogen being particularly attractive because of its abundance and inherently clean nature. A monolithic Photoelectrochemical (PEC) device that produces hydrogen by electrolyzing water directly from sunlight has the benefit of utilizing "free" solar energy to drive the reaction.

Although α-Fe 2 O 3 …

The Isotopological Homodesmotic Reaction: A Further Refinement To The Quantification Of Aromaticity, Marco Olguin

Open Access Theses & Dissertations

Aromaticity imparts a significant energetic stabilization to various chemical systems as a result of cyclic pi-electron delocalization. One of the most widely used methods for the quantification of the Aromatic Stabilization Energy (ASE) of a molecule is the formulation of a Homodesmotic reaction. The following research employs a refined Homodesmotic approach based on previous work by Herndon and Mills which utilized Isotopological Homodesmotic Reactions (IHR) to determine the Aromatic Stabilization Energy (ASE) of a flourenyl cation. The advantage of employing an IHR for an ASE calculation is that the strain energy contribution from the sigma framework of reactant and product …

Study Of Corrosion Of Materials In The Sulfur-Iodine Hydrogen Production Cycle, Thao Trung Ho

UNLV Theses, Dissertations, Professional Papers, and Capstones

Hydrogen is of great interest since the availability of traditional fossil fuels is in decline. Strictly speaking, hydrogen is not a primary source of energy but is an energy carrier, since energy typically must be used from another source (electricity, natural gas, coal, etc.) to produce it. Of hydrogen production techniques, the Sulfur-Iodine thermochemical water splitting process (S-I cycle), which was proposed by General Atomics (GA), is promising with its simplicity and high efficiency. Most of the chemicals are recycled except water. However, the S-I cycle operates in a harsh, corrosive environment in the presence of a mixture of iodine …

The Effect Of Adsorbent Geometry And Surface Chemistry On Hplc Retention, Zhaoxia Liu

Seton Hall University Dissertations and Theses (ETDs)

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Microwave Syntheses And Thermal Gravimetric Analysis Of Trans-Hydrogen Bis(Dimethylsulfoxide)Tetrachlororuthenate(Iii), S. Chui, Mark Draganjac, E. Benjamin, B. Rougaeu

Journal of the Arkansas Academy of Science

No abstract provided.

Microwave Synthesis Of Cis-Dichlorotetrakis(Dimethylsulfoxide)Ruthenium(Ii), A. Harvey, Mark Draganjac, S. Chui, R. Snell, E. Benjamin

Journal of the Arkansas Academy of Science

No abstract provided.