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Full-Text Articles in Engineering
A Study Of The Diffusion Characteristics Of Tungsten Bar Stock And Tungsten Produced Via Direct Metal Laser Sintering (Dmls), Jonathan Robert Bruss
A Study Of The Diffusion Characteristics Of Tungsten Bar Stock And Tungsten Produced Via Direct Metal Laser Sintering (Dmls), Jonathan Robert Bruss
Master's Theses (2009 -)
Using a vacuum hot extraction method diffusivity and concentration of hydrogen were measured in samples of tungsten bar stock and direct metal laser sintered (DMLS) tungsten. It was found that the tungsten bar stock closely adhered to the model established by Frauenfelder. The DMLS samples approximately follow a downward sloping trend over the 500K-1200K temperature range. The trend is opposite of what is expected suggesting processing has a major effect on diffusion behavior. A CFD model was created using ANSYS Fluent to simulate the diffusion behavior. The model functions by separating out diffusion mechanisms and solving Fick’s law with each …
Doped Tio2 Nanowires For Applications In Dye Sensitized Solar Cells And Sacrifical Hydrogen Production, Qasem Alsharari
Doped Tio2 Nanowires For Applications In Dye Sensitized Solar Cells And Sacrifical Hydrogen Production, Qasem Alsharari
Electronic Thesis and Dissertation Repository
This thesis explores the synthesis of metal oxide 1-D nanowires using a sol-gel method in supercritical carbon dioxide (sc-CO2), as an environmental friendly enabling solvent. Porous nanowires were synthesized and their performance was tested in dye sensitized solar cell and sacrifical hydrogen production. Titanium isopropoxide (TIP) was used as a precursor for titania synthesis while copper, bismuth and indium were examined as dopants, respectively. The sol-gel reactions were catalyzed by acetic acid in CO2 at a temperature of 60 °C and pressure of 5000 psi. It was observed that acetic acid/monomer ratio > 4 produced nanowires while a …
Ruo2 Nanorods As An Electrocatalyst For Proton Exchange Membrane Water Electrolysis, Richard Smith
Ruo2 Nanorods As An Electrocatalyst For Proton Exchange Membrane Water Electrolysis, Richard Smith
Graduate College Dissertations and Theses
The desire for pure diatomic hydrogen gas, H2(g), has been on the rise since the concept of the hydrogen economy system was proposed back in 1970. The production of hydrogen has been extensively examined over 40 + years as the need to replace current fuel sources, hydrocarbons, has become more prevalent. Currently there are only two practical and renewable production methods of hydrogen; landfill gas and power to gas. This study focuses on the later method; using various renewable energy sources, such as photovoltaics, to provide off-peak energy to perform water electrolysis. Efficient electrolysis takes place in electrochemical cells which …
Study On The Hydrogen Permeation Through Zinc Electrodeposit, Jiangli Cao, Jixun Wu, Yanping Lu, Jie Shi
Study On The Hydrogen Permeation Through Zinc Electrodeposit, Jiangli Cao, Jixun Wu, Yanping Lu, Jie Shi
Journal of Electrochemistry
The electrochemical hydrogen_permeation technique was used to study hydrogen permeation through zinc electrodeposit with bilayer specimens of Fe substrate/zinc electrodeposit.The effect of coating thickness on hydrogen diffusion coefficient and hydrogen steady-state flux was studied. The results showed that hydrogen diffusion coefficient was approximately in the range of 10-11 cm2s-1 rank and zinc coating could retard hydrogen permeation. Accordingly, hydrogen steady_state flux and effective diffusion coefficient declined while the coating thickness increased.