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Full-Text Articles in Physical Sciences and Mathematics

Studies Of Optical And Electronic Properties Of Nanoparticles For Solar Energy Conversion, Caitlin Kruse, Libai Huang Aug 2015

Studies Of Optical And Electronic Properties Of Nanoparticles For Solar Energy Conversion, Caitlin Kruse, Libai Huang

The Summer Undergraduate Research Fellowship (SURF) Symposium

The higher energy needs for today's technological society requires sustainable and renewable energy source, such as solar energy. This study focuses on using semiconducting quantum dots and fluorescent dyes as light absorbers for solar energy conversion devices such as solar cells. Quantum dots are small nanocrystals (usually 2-10 nm in diameter) with tunable absorbing properties. The smaller the dot, the shorter the wavelength being absorbed. Quantum dots are extremely efficient light absorbers and emitters. Fluorescent dyes have a high quantum yield. In order to examine the energy conversion, cadmium selenide (CdSe) quantum dots and Rhodamine 6G (R6G) dye were spin …


Mass Spectrometric Characterization Of Peptide Radical Ions And Implication For Radical Chemistry, Lei Tan Apr 2015

Mass Spectrometric Characterization Of Peptide Radical Ions And Implication For Radical Chemistry, Lei Tan

Open Access Dissertations

Gas-phase radical ion chemistry has attracted increasing research interest from the mass spectrometry (MS) society because it provides new capabilities in bio-analysis which often complements traditional MS methods developed from even-electron ions. Fundamental studies of biomolecule related radical species are essential to broadening the scope of radical chemistry and pushing the frontiers of its analytical applications. This dissertation mainly discusses the gas-phase chemistry of peptide sulfinyl radicals (-SO·), which has been rarely studied before. In order to establish an effective research approach, a method that can generate site-specific peptide sulfinyl radical ion has been developed. This method is based on …


A Bracketing Method For Proton Affinity Measurements Of Dehydro-And Didehydropyridines, Guannan Li Apr 2015

A Bracketing Method For Proton Affinity Measurements Of Dehydro-And Didehydropyridines, Guannan Li

Open Access Theses

Proton affinity (PA) is a fundamental property that is related to the structure and reactivity of a molecule. Currently, very few experimental PA values are available for organic radicals and none for biradicals. Equilibrium methods cannot be used for these measurements. The traditional bracketing method is based on monitoring reactions of different reference bases with known proton affinities with the protonated analyte for the occurrence of exothermic proton transfer to determine the upper and lower limits of proton affinity. However, the energy deposited into the precursor ions upon CAD when forming protonated radicals may cause endothermic proton transfer reactions occur …


Quantification Of Molecular Aggregation Equilibria Using Spectroscopic Measurements And Random Mixing Modeling, Blake M. Rankin Apr 2015

Quantification Of Molecular Aggregation Equilibria Using Spectroscopic Measurements And Random Mixing Modeling, Blake M. Rankin

Open Access Dissertations

Molecular aggregation equilibria, such as the binding of ligands to a central solute molecule, are prevalent throughout biological processes and energy storage devices. However, both the sign and magnitude of hydrophobic and ionic interactions remains a subject of theoretical debate, and has yet to be experimentally determined. Here, Raman vibrational spectroscopy is combined with multivariate curve resolution (Raman-MCR) to experimentally quantify both the number of hydrophobic contacts between alcohol molecules in water and the affinity of ions for molecular hydrophobic interfaces. Furthermore, a generalized theoretical model is developed based on random statistics in which it is assumed that the concentration …