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Full-Text Articles in Engineering
Technical Evaluation Of Hardwood Biorefinery Using The "Near-Neutral" Hemicellulose Extraction Process, Haibo Mao
Electronic Theses and Dissertations
A technical analysis was performed for a new process that produces ethanol and acetic acid from hardwood in addition to bleached hardwood Kraft pulp. The new process, termed the "near neutral" hemicellulose extraction process, involves the extraction of wood hemicellulose using green liquor prior to conventional Kraft pulping. This thesis assumes that the new process is located at an existing kraft pulp mill. Ancillary unit operations in the process include hydrolysis of the extracted carbohydrates using sulfuric acid, filtration of the extract to remove lignin that was extracted with the carbohydrates, liquid-liquid extraction of acetic acid and by-product furfural, liming …
Sub-Femtomolar Isothermal Desoprtion And Reaction Kinetics On Microhotplate Sensor Platforms, Amol G. Shirke
Sub-Femtomolar Isothermal Desoprtion And Reaction Kinetics On Microhotplate Sensor Platforms, Amol G. Shirke
Electronic Theses and Dissertations
The population of adsorbates on a semiconductor surface directly influences the physical and chemical properties of the semiconductor. In the case of a metal-oxide semiconductor, the adsorbing species can change its electrical conductivity, a phenomenon which forms the operating principle of gas sensors. The interaction of adsorbed oxygen species on a metaloxide surface with reducing or oxidizing gases leads to an increase or decrease in electrical conductivity respectively. Miniature gas sensors called microhotplates (developed at the National Institute of Standards and Technology) are excellent surface science tools to explore surface reactions on semiconducting metal-oxide films. This thesis outlines how the …
Kinetics And Mechanism Of Oxygen Delignification, Yun Ji
Kinetics And Mechanism Of Oxygen Delignification, Yun Ji
Electronic Theses and Dissertations
Considerable research has been conducted into the kinetics and selectivity of the oxygen delignification process to overcome limitation in its use. However most studies were performed in a batch reactor whereby the hydroxide and dissolved oxygen concentrations are changing during the reaction time in an effort to simulate tower performance in pulp mills. This makes it difficult to determine the reaction order of the different reactants in the rate expressions. Also the lignin content and cellulose degradation of the pulp are only established at the end of the experiment when the sample is removed from the batch reactor. To overcome …
Modification Of Semi-Metal Oxide And Metal Oxide Powders By Atomic Layer Deposition Of Thin Films, Mark Q. Snyder
Modification Of Semi-Metal Oxide And Metal Oxide Powders By Atomic Layer Deposition Of Thin Films, Mark Q. Snyder
Electronic Theses and Dissertations
This work describes two methods of modifying, and the subsequent characterizing of, oxide nanopowders. The first method, atomic layer deposition, or ALD, is a series of surface-limited reactions that are repeated to deposit a thin, inorganic film on the surface of the nanopowder. Deposition of a thin film is a useful method to alter the surface properties of a material while retaining its bulk properties. Part of this thesis concerns the understanding of the growth mechanism of thin film titanium nitride (a material known for thermal and chemical stability as well as electronic conductivity) on silica through the ALD process. …