Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 3 of 3

Full-Text Articles in Physical Sciences and Mathematics

Perfluoroalkyl Phosphonic And Phosphinic Acid Electrolytes For Proton Exchange Membrane Fuel Cells, Mahesha Herath Aug 2010

Perfluoroalkyl Phosphonic And Phosphinic Acid Electrolytes For Proton Exchange Membrane Fuel Cells, Mahesha Herath

All Dissertations

Perfluorinated sulfonic acid polymers have been considered as the state-of-art membrane materials for proton exchange membrane fuel cells. A major technical issue with these polymers is that they do not function well at temperatures above 80 °C and at low humidities. Therefore, research has been focused on developing PEM materials that can operate independent of hydration requirements. The operation of fuel cells at high temperature (e.g. 120 oC) increases fuel cell system efficiency due to faster electrode kinetics and better CO tolerance. This dissertation will describe a study of proton-transport rates and mechanisms under anhydrous and aqueous conditions using a …


Chemical Characterization Of Botanical Products: Comprehensive Speciation By Liquid Chromatography Particle Beam Mass Spectrometry, Joaudimir Castro Georgi May 2010

Chemical Characterization Of Botanical Products: Comprehensive Speciation By Liquid Chromatography Particle Beam Mass Spectrometry, Joaudimir Castro Georgi

All Dissertations

The dietary supplement industry has expanded and many of these supplements have become an important aspect of people's everyday lives. In 1994, the U.S. Dietary Supplement Health and Education Act (DSHEA) classified numerous nutraceutical/botanical products as dietary supplements because of their beneficial medicinal properties and provided the necessary regulation to the supplement producers. Since then, the interest of the scientific community towards dietary supplements has grown intensively and numerous studies have been carried out in order to understand the chemical behavior of the active molecules in the human body. The development towards analytical methods for the quantification of the active …


Comparison Of Rna Quality From Stressed And Unstressed Recombinant Escherichia Coli, Mary Alice Salazar May 2010

Comparison Of Rna Quality From Stressed And Unstressed Recombinant Escherichia Coli, Mary Alice Salazar

All Theses

High quality, intact RNA is required for DNA microarray studies, cloning, and reverse transcriptase polymerase chain reaction (rt-PCR) analysis. There are several analytical methods used to assess the RNA quality. The RNA Integrity Number (RIN) from the Agilent Bioanalyzer is one quality control assay used to evaluate RNA. For recombinant Escherichia coli cultured under stressful conditions the RNA profiles obtained using the Agilent Bioanalyzer indicate RNA degradation; however, RNA obtained and purified in parallel from unstressed recombinant cultures indicate acceptable RNA values without significant degradation. We proposed that for stressed E. coli the RIN value is not necessarily indicative of …