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Full-Text Articles in Physical Sciences and Mathematics

Volume Averaged Modeling Of The Oxidation Of Porous Carbon Fiber Material, Alexandre Martin Jun 2013

Volume Averaged Modeling Of The Oxidation Of Porous Carbon Fiber Material, Alexandre Martin

Mechanical Engineering Faculty Publications

Charring ablators remain the premium choice for space exploration missions that involve atmospheric re-entry. This type of ablative material is composed of a carbon matrix, usually made of fibers, which is then impregnated with a resin. During re-entry, the high heat flux produced by convective heating causes the material to chemically react. First, the resin pyrolyzes, and is vaporized into a gas that travels through the material, and is eventually ejected at the surface. Then, as the temperature rises, the surface of the porous matrix recess through ablative processes. For re-entry conditions typical of space exploration missions, this is mainly …


Simulation Of Electronic Processes Of Nanoenergetic Gas Generator Using Cabrera Mott Oxidation Model, Zamart Ramazanova Jun 2013

Simulation Of Electronic Processes Of Nanoenergetic Gas Generator Using Cabrera Mott Oxidation Model, Zamart Ramazanova

Theses and Dissertations - UTB/UTPA

This research study is a theoretical framework for understanding rapid thermal processes which occur during the performance of new Nanoenergetic Gas-Generators (NGG) systems that rapidly release a large amount of gaseous products and generate a fast-moving thermal wave during the explosion. The kinetics of rapid oxidation of metal nanoparticles acquires practical importance with the quickly developing nanoenergetic systems. The thin film oxidation theory of Cabrera-Mott model was examined for a spherically symmetric case and used to analyze the physical importance of the exothermic processes for prediction of the reaction time and front velocity. A rapid kinetic of oxide growth on …


Photocatalytic Oxidation Of Methanol Using Titanium Dioxide/Single-Walled Carbon Nanotube Composite, Jun Chen, Carol M. Lynam, Chonlada Dechakiatkrai, Gordon G. Wallace, Sukon Phanichphant Mar 2013

Photocatalytic Oxidation Of Methanol Using Titanium Dioxide/Single-Walled Carbon Nanotube Composite, Jun Chen, Carol M. Lynam, Chonlada Dechakiatkrai, Gordon G. Wallace, Sukon Phanichphant

Gordon Wallace

Titanium dioxide/single-walled carbon nanotube TiO2/SWNT composites were prepared for photocatalytic applications. Thecomposites were characterized using UV-visible and Raman spectroscopy, zeta-potential measurements, cyclic voltammetrycoupled with a photoreactor, scanning electron microscopy, and transmission electron microscopy coupled with energy dispersiveX-ray spectroscopy. The photocatalytic activity of TiO2 and the TiO2/SWNT composite was investigated using the photo-oxidationof methanol in sulfuric acid as supporting electrolyte. The results indicate that the TiO2/SWNT composite enhances the photocatalyticactivity compared to TiO2 alone. Electrochemical studies of the TiO2/SWNT composite were also carried out in varioussupporting electrolytes and the presence of SWNTs was shown to increase the current achieved in voltammetric …


A Light-Assisted, Polymeric Water Oxidation Catalyst That Selectively Oxidizes Seawater With A Low Onset Potential, Jun Chen, Pawel W. Wagner, Lei Tong, Danijel Boskovic, Weimin Zhang, David L. Officer, Gordon G. Wallace, Gerhard F. Swiegers Jan 2013

A Light-Assisted, Polymeric Water Oxidation Catalyst That Selectively Oxidizes Seawater With A Low Onset Potential, Jun Chen, Pawel W. Wagner, Lei Tong, Danijel Boskovic, Weimin Zhang, David L. Officer, Gordon G. Wallace, Gerhard F. Swiegers

Australian Institute for Innovative Materials - Papers

Vapour phase polymerisation (vpp) of PEDOT to incorporate high levels of a sulphonated manganese porphyrin yields a vivid green conducting polymer that, under illumination, catalyzes selective oxidation of water from seawater from ca. 0.40 V (vs. NHE; Pt counter electrode) without observable chlorine formation. This onset potential is comparable to that of certain metal oxide semiconductors that achieve higher photocurrents but are not capable of selectively oxidising the water in seawater.


Mass Spectrometric Analysis Of Oxidized Eicosapentaenoic Acid Sodium Salt, Kelsey D. Jordan, Rita K. Upmacis Jan 2013

Mass Spectrometric Analysis Of Oxidized Eicosapentaenoic Acid Sodium Salt, Kelsey D. Jordan, Rita K. Upmacis

Faculty Papers and Publications

Eicosapentaenoic acid (EPA) is an omega-3 polyunsaturated fatty acid (PUFA) with 20 carbon atoms and 5 carbon-carbon double bonds. Mammalian cells cannot synthesize long chain PUFAs such as EPA de novo, and, thus, the most effective way to enrich cells in EPA is by dietary intake of fish oils. EPA supplementation causes an increase in its concentration in plasma lipids and in cell membrane phospholipids. Many beneficial effects of EPA supplementation have been noted, including (1) the potential to sensitize cancerous tumors towards chemotherapy, (2) the promotion of cardiovascular health, and (3) the alleviation of some mental disorders, but results …


Oxidation Of Gold Clusters By Thiols, Brian M. Barngrover, Christine M. Aikens Jan 2013

Oxidation Of Gold Clusters By Thiols, Brian M. Barngrover, Christine M. Aikens

Faculty Publications

The formation of gold–thiolate nanoparticles via oxidation of gold clusters by thiols is examined in this work. Using the BP86 density functional with a triple ζ basis set, the adsorption of methylthiol onto various gold clusters AunZ (n = 1–8, 12, 13, 20; Z = 0, −1, +1) and Au384+ is investigated. The rate-limiting step for the reaction of one thiol with the gold cluster is the dissociation of the thiol proton; the resulting hydrogen atom can move around the gold cluster relatively freely. The addition of a second thiol can lead to H2 …


Unidirectional Suppression Of Hydrogen Oxidation On Oxidized Platinum Clusters, Yu Li, Jun Xing, Zong Chen, Zhen Li, Feng Tian, Li Zheng, Hai Wang, P Hu, Huijun Zhao, Huagui Yang Jan 2013

Unidirectional Suppression Of Hydrogen Oxidation On Oxidized Platinum Clusters, Yu Li, Jun Xing, Zong Chen, Zhen Li, Feng Tian, Li Zheng, Hai Wang, P Hu, Huijun Zhao, Huagui Yang

Australian Institute for Innovative Materials - Papers

Solar-driven water splitting to produce hydrogen may be an ideal solution for global energy and environment issues. Among the various photocatalytic systems, platinum has been widely used to co-catalyse the reduction of protons in water for hydrogen evolution. However, the undesirable hydrogen oxidation reaction can also be readily catalysed by metallic platinum, which limits the solar energy conversion efficiency in artificial photosynthesis. Here we report that the unidirectional suppression of hydrogen oxidation in photocatalytic water splitting can be fulfilled by controlling the valence state of platinum; this platinum-based cocatalyst in a higher oxidation state can act as an efficient hydrogen …