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 14 of 14 for “"Hydrothermal Stability"”.
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Carbon Coating for Improved Hydrothermal Stability of Silica Supports
… and alumina, will not work because they are not hydrothermally stable. Silica and alumina are used as catalyst supports because they are mechanically stable, have large surface areas, and synthesis methods are well established but they tend to react with water and lose their integrity during …
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Hydrothermal stability of hierarchically-structured two-dimensional MFI zeolite nanosheets
… very limited knowledge is available on their hydrothermal stability under industrially-relevant conditions. The hydrothermal stability of the thin crystalline domains governs their enhanced use as selective catalysts, adsorbents and in thin membranes’ preparation. This dissertation focuses on …
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An investigation of the hydrothermal stability and mineralisation of collagen and their relationship
Mineralised collagen displays an improved hydrothermal stability compared to collagen that is unmineralised. The possibility of using in-vitro partial mineralisation of collagen as a method of increasing the hydrothermal stability was investigated. Remineralisation experiments using demineralised …
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Hydrothermal aging of zeolite-based catalysts
… and alumina-silica gel matrix, was treated hydrothermally under simulated FCC regenerator conditions in a laboratory scale fluidized bed. Fresh and steam-aged catalysts were characterized by surface area reduction using the nitrogen BET and t-Plot surface area methods. The surface morphology …
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Hydrothermally stable heterogeneous catalysts for biorenewable-derived molecule conversions to chemicals
… difficulty by developing new catalysts with a hydrothermally stable scaffold and active group.</p> <p>From this work the development of the carbon catalyst is shown. First, I investigated of the hydrothermal stability of the current carbon catalysts in literature. Second, some model compound …
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Study of Neem bark tannins for the leather industry
… with the rest of the techniques used. The hydrothermal stability of neem bark tannin tanned and crosslinked hide powder and leathers was found to be paralleled to mimosa tannin extract. Studies of the physical properties of tanned and retanned leathers showed corn pai.ahility of micem bark …
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Ab initio molecular dynamics simulations of lanthanide coordination structures in water and in faujasite
… mechanisms by which lanthanum increases the hydrothermal stability of faujasite in cracking catalysts, as well as in cation exchange in faujasite. The structures of the lanthanide aqua ions were resolved with density functional theory calculations and ab initio molecular dynamics (AIMD) …
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Enhancing Zeolite Synthesis with Tailored Structure-Directing Agents (SDAs) and High-throughput Platform
… implies a significant improvement in zeolites’ hydrothermal stability, potentially enhancing their catalytic lifetime and overall performance in targeted reactions. In summary, this thesis offers an innovative, efficient, and versatile methodology for zeolite synthesis. The proposed …
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Relationships between crystal structure, bonding and thermal stability of amphiboles
… for the physical conditions of their formation. Hydrothermal stability studies of several amphibole endmembers have demonstrated that the FeMg₋₁ substitution produces a wide spread in thermal stability. The crystal structure, upon substitution, responds to the differences in cation size and site …
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Metal induced degradation of leather
… was characterised in terms of the decline in hydrothermal stability, progressive lowering of tensile strength, loss of metal-tannin binding interactions, changes in the fibre structure and the occurrence of gelatinisation. Direct evidence on the reduction of V(V) by tannins was obtained using …
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Nanocomposite catalysts for soot combustion and propane steam reforming
… excellent activity, coke resistance and thermal/hydrothermal stability of Re,V-promoted nickel aluminate nanocomposite would be attractive towards H2 generation for fuel cell applications, especially in portable devices.
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Design of Robust Heterogeneous Catalysts for Sustainable Chemistry
… The microporous materials showed good thermal stability and activity in selective hydrogenation of aryl acetylenes but as polymer to ceramic conversion was not complete at 600°C, the materials possessed low hydrothermal stability at higher temperatures due to the hydrolysis of Si-N bonds. In …
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Sillica Nanoporous Materials Adsorption and Release Study
… parameter for providing a high degree of hydrothermal stability and improved mechanical stability compared to mesoporous MCM-41 and related silicas, and thus a sufficiently long lifetime in biological environments. Therefore, SBA-15 mesoporous materials could be modified with various …
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Fundamental studies on copper zeolites for catalytic NO x abatement
… SCR applications because it shows exceptional hydrothermal stability in addition to commercially viable SCR performance. Our work focuses on 1) determination of the active sites, and 2) elucidation of the dominant reaction steps on active sites, for standard SCR (at 473 K) and catalytic …