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 25 for “"in situ Raman spectroscopy"”.
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In situ Raman spectroscopy of lanthanum-strontium-cobaltite thin films
Raman spectroscopy is used to probe the structural change of Lanthanum Strontium Cobaltite (La1.xSrxCoO 3 -8) thin films across change in composition (0%-60% strontium) and temperature (30*C-520°C). Raman shift peaks were identified and correlated with specific vibrational modes. Results were …
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In situ Raman spectroscopy of pressure-induced phase transformations in DyPO₄ and GdxDy(1-x)PO₄
… at ambient temperature under high pressures inside a diamond anvil cell with in situ Raman spectroscopy. The Raman active modes of the xenotime structure were observed at low pressures and the appearance of new Raman peaks at higher pressures indicate a phase transformation to a lower …
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Light as a universal tool : Microcapsule sizing by elastic light scattering and mineral investigation by in situ Raman spectroscopy
… of two major parts. The first part, extending over chapters 1, 2, 3 and 4, addresses the design and construction of a device capable of determining the shell thickness and the core size for monolayer spherical particles in a flow. The second part containing chapters 5, 6, 7, 8, 9 and 10, …
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Investigating the nature of passive films on austenitic stainless steels
… and breakdown of the passive film on stainless steels are mainly controlled by ionic and electronic transport processes. Both these processes are in part controlled by the electronic properties of the oxide film. Consequently it is vital to gain a detailed perception of the electronic …
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Vibrational spectroscopic techniques (Raman, FT-IR and FT-NIR spectroscopy) as a means for the solid-state structural analysis of pharmaceuticals
… of vibrational spectroscopic techniques (Raman, FT-IR and FT-NIR spectroscopy) as a means for the solid-state structural analysis of pharmaceuticals. Budesonide, fluticasone propionate, salbutamol hemisulfate, terbutaline hemisulfate, ipratropium bromide, polymorphic forms of salmeterol …
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Ozone Decomposition and Acetone Oxidation on Manganese Oxide Catalysts
… manganese oxide catalysts and their application in the oxidation of acetone, a typical volatile organic compound (VOC), and ozone decomposition. This topic is of great value because of environmental concerns of the elimination of the harmful VOCs and ozone. Manganese oxide was chosen because it …
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Electrochemical Pathways to Decarbonizing Urea and Ammonia Production
… challenges of the 21st century, and chemical engineers have a critical role to play in addressing it by designing processes that not only minimize carbon emissions but also have the potential to reverse them. This thesis focuses on decarbonizing the production of ammonia, a chemical indispensable …
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Understanding phase transformations during flash sintering
Improving the efficiency of synthesis methods in addition to establishing methods to produce novel materials or materials that are difficult to synthesize are driving factors in research for materials science. Flash sintering is both a method to densify ceramics within seconds and a method to …
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Structural heterogeneity in silk fibers and its effects on failure mechanics and supercontraction
Spider dragline silk is a protein material that has evolved over millions of years to become one of the strongest and toughest natural fibers known. Silk features a heterogeneous structure that comprises [beta]-sheet crystals embedded in an amorphous matrix. However, it is not fully understood how …
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Mechanisms In the Water Vapor Hydrolysis of Sodium Borohydride
… volumetric capacities of NaBH<sub>4</sub> combined with its relatively low cost make it a prominent near-term candidate for hydrogen storage. In addition to hydrogen, hydrated sodium metaborate (NaBO<sub>2</sub>·xH<sub>2</sub>O), is formed as a byproduct. The term x represents the excess …
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VOC Catalytic Oxidation on Manganese Oxide Catalysts Using Ozone
… describes the current and common problem of removing low concentrations of pollutants known as volatile organic compounds (VOCs) from large volume gas emissions. Silica-supported manganese oxide catalysts with loadings of 3, 10, 15, and 20 wt. % (as MnO2) were characterized using x-ray absorption …
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Kinetics and Mechanism of Ozone Decomposition and Oxidation of Ethanol on Manganese Oxide Catalysts
Understanding and establishing reaction mechanisms is an important area in heterogeneous catalysis. This dissertation describes the use of in situ laser Raman spectroscopy combined with kinetic measurements and dynamic experiments to determine the mechanism of catalytic reactions. Two cases …
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Synthesis, characterization and catalytic testing of metal tungstates as catalysts for activation of lower alkanes
… and structural properties of vanadium-containing phases govern the formation of isolated active sites at the surface of these catalysts for selective alkane oxidation. This concept is not restricted to vanadium oxide. The deliberate use of hydrothermal techniques can turn the typical …
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Understanding Liquid-Air Interface Corrosion of Steel in Simplified Liquid Nuclear Waste Solutions
Carbon steel is susceptible to the liquid-air interface (LAI) corrosion in liquid nuclear waste and in simulants, but a precise understanding of the mechanism is still missing. This work aimed to expand the understanding of the LAI corrosion mechanism.LAI corrosion was found to initiate at the very …
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Electrocatalytic dioxygen reduction with copper complexes
… while very exothermic (-474 kJ/mol), remains a difficult reaction to harness due to the high O-O bond strength (485 kJ). Many proteins in nature couple the ORR to various substrate oxidations in order to provide energy, such as in respiration. Commercially, the ORR is important in a large …
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New high pressure phase transition of natural orthoenstatite and sound velocity measurements at simultaneous high pressures and temperatures by laser heating
… and sound velocities of candidate mantle minerals under high-pressure high-temperature conditions are essential for understanding the mineralogical composition and physical processes of Earth’s interior. Phase transitions in candidate deep earth minerals under high-pressure high-temperature …
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Structure and Glass Transition Behavior of As-Rich As-Se Glasses: Modeling and Experiment
Chalcogenide glasses have been widely used in various technologies due to their wide IR transparency and good glass forming ability. Arsenic selenide glasses (AsxSe100-x), in particular, have been readily adopted for IR applications and widely studied to provide insights into fundamental …
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Strategies to tune active site environments for alkene epoxidations with H2O2 over supported transition metal atoms
Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2022-11-15 without embargo terms
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Carbon dioxide hydrates for carbon capture, utilization, and storage
With global temperatures continuing to rise, actions like carbon capture, utilization, and storage (CCUS) must be taken to halt and even reverse this trend. In all stages of CCUS, carbon dioxide properties must be well characterized for any of these schemes to work. With the high pressures and …
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A noninvasive screening tool for cell fate determination using raman spectroscopy and machine learning in tissue engineering and microbiology applications
… are a small heterogeneous pool of self-renewing cells responsible for maintaining the blood and immune system in the human body. The hematopoietic systems of patients suffering from immune or hematological disorders may be reconstituted through the transplantation of healthy HSCs. Transplant …
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