Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 21 for “"Hydrogen Uptake"”.
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Effective Optimization of Catalytic Hydrogenations Using a Rationally Designed Hydrogen Uptake System
… a reactor material, to perform as an effective hydrogenation catalyst at temperatures above 100 oC, under reducing aqueous-acidic media. Additionally, an external apparatus was developed in order to facilitate the optimization of catalytic hydrogenations. The accuracy and applicability of this …
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Effects of hydrogen uptake and yttrium doping on the oxidation of zirconium-yttrium alloys
… nuclear reactors is susceptible to significant hydrogen uptake during normal operating conditions. This results in the formation of zirconium hydride. The nucleation of a brittle hydride phase results in a degradation of cladding mechanical properties in the long term as plate-like hydrides …
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Hydrogen sorption in palladium doped microporous materials
This research investigated “hydrogen spillover” which has been suggested to improve the hydrogen uptake of bridged and chemically doped porous materials at room temperatures. XRD, Temperature Programmed Desorption and hydrogen sorption measurements were used to characterise the as-received and …
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Hydrogen permeation in uncoated and coated X60steel
The sustainable storage and transport of hydrogen represent major challenges for the deployment of renewable energy systems, requiring a comprehensive understanding of hydrogen–material interactions in pipeline steels and effective strategies to limit hydrogen uptake. This PhD research investigates …
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Hydrogen physisorptive storage in metal-organic frameworks (MOFs)
… gained great popularity in recent years has been hydrogen. The characteristics which it possesses make it an ideal alternative to fossil fuels for on-board energy generation and also for stationary (portable) power applications. Widespread use of hydrogen as an energy carrier can only be realised …
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The relative susceptibility of ferrous alloys to hydrogen embrittlement determined by effective electrolytic hydrogen pressure measurement
Electrochemical hydrogen charging experiments with AISI 1018 and 410 steels showed that when these steels were cathodically charged under experimentally identical conditions, both the hydrogen uptake and transport characteristics and the effective hydrogen pressures developed at the charged …
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Use of nitrous oxide as the terminal electron acceptor during growth and respiration of Bradyrhizobium Japonicum USDA 143
… cathode, and the instrumentation for monitoring hydrogen uptake amperometrically were used to monitor the reduction of N₂O during anaerobic respiration.
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Tuneable graphite intercalates for hydrogen storage
The development of hydrogen as an energy transfer mechanism is of great importance to alleviate environmental damage and economic destabilisation caused by over-reliance on oil, as long as the hydrogen can be generated renewably. To be suitable for road transport applications, safe and compact …
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Sustainable Mechanochemical Synthesis and Manufacturing of Metal-Organic Frameworks for Enhanced Hydrogen Storage
… the need for sustainable and efficient hydrogen storage solutions to replace fossil fuels is becoming increasingly urgent. This thesis investigates sustainable mechanochemical processing routes for metal-organic frameworks (MOFs), focusing on enhancing the hydrogen storage performance of …
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Estudo da permeação de hidrogênio e fragilização pelo hidrogênio de um aço API 5L X80
… comes the concern about the risks involving hydrogen diffusion and hence, embrittlement due to severe operational conditions and corrosive environment containing hydrogen sulphide (H2S). Although many efforts have been made to predict and understand those phenomena, the mechanisms involving …
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Chemolithotrophic nitrate dependent growth of Rhizobium japonicum on carbon monoxide and its relationship to hydrogenase activity
… growth was correlated with the growth rate. Hydrogen uptake was measured amperometrically with cells grown in the presence of CO with nitrate, nitrite, nitrous oxide or oxygen serving as the electron acceptor. Addition of acetylene, in the presence of N₂O resulted in a 92.5% inhibition of …
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Hydrogenase of Clostridium acetobutylicum ATCC 824
… that produces acetic and butyric acids, hydrogen gas, and carbon dioxide during the exponential phase of growth. When the culture pH is allowed to remain near 4.5, the metabolism switches to the production of the neutral compounds (solvents) - acetone, n-butanol, and ethanol. The two …
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Stress corrosion cracking and corrosion of carbon steel in simulated fuel-grade ethanol
… also investigated to understand the oxygen and hydrogen reactions. Hydrogen uptake into the pipeline steel and the conditions of the fractures related to hydrogen embrittlement were identified and studied.
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Recovery Of Hydrogen And Helium From Their Mixtures Using Metal Hydrides
Waste streams of hydrogen and helium mixtures are produced at the Kennedy Space Center during purging of the hydrogen systems and supply lines. This process is done prior to and after hydrogen servicing. The purged waste gases are lost to the atmosphere, resulting in an annual loss of 2 million and …
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Investigation of Pd-Ti and Ni-Ti Multilayer Thin Films for Enhanced Hydrogen Storage Capacity
… of compact and secure storage solutions for hydrogen in solid-state materials presents significant challenges and demands. High-capacity storage technologies that operate effectively at low pressures and exhibit favourable kinetics in absorption and desorption are essential for hydrogen …
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Assessing thermo-mechanical performance of ThO₂ and SiC clad light water reactor fuel rods with a modular simulation tool
… neutron fluence on the accelerated oxidation and hydrogen pickup by Zircaloy-2 have been investigated and incorporated. In developing the ThO2-based RBWR concept, three designs have been proposed based on different goals and applied assumptions. With the exception of hydrogen uptake, none of the …
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Functionalization, growth and applications of single wall carbon nanotubes
… SWNTs for electrochemically-induced hydrogen storage, in-situ formation of new polymer and ceramic nanocomposites with SWNTs, and the fabrication and study for the first time, to the best of our knowledge, of a SWNT-based biofuel cell and self-powered biosensor, are the thrusts of the …
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Hydrogen in thin film niobium
"An experimental study of hydrogen dissolved in thin films of niobium is presented. The chief techniques used were x-ray diffraction and ion-beam hydrogen profiling. Niobium was grown on sapphire substrates by molecular beam epitaxy, resulting in high quality films. It has previously been shown …
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Influence Of Dissolved Hydrogen On The Fatigue Crack Growth Behaviour Of Aisi 4140 Steel
… structural components come into contact with hydrogen during manufacturing processes or forming operations such as hot stamping of auto body frames and while in service. This interaction of metallic parts with hydrogen can occur due to various reasons such as water molecule dissociation during …
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Response of chromium and chromium-aluminum coatings on zircaloy-2 to high temperature steam
… was studied in 700C steam environment. Hydrogen generated from the steam oxidation of uncoated Zr were absorbed and formed δ-hydrides in Zircaloy matrix. Synchrotron XRD demonstrated that longer exposure times increased hydride peak intensity and decreased intermetallic SPPs peak …
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