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 20 for “"In-situ Xrd"”.
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A layered sodium titanate as promising anode material for sodium ion batteries
… have been proposed, it's quite challenging to develop suitable anode materials with high energy density and good cyclability for sodium ion batteries. Herein, we report a layered material, 03-NaTiO2, that delivers 130mAhg-1 of reversible capacity and presents excellent cyclability with …
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Determination of the synthesis diagram of sodium cobalt oxide and electrochemical study
… 450°C to 750°C by solid-state reactions with initial Na:Co ratio ranging from 0.60 to 1.05. Four monophasic domains of' O3, O3', P3' and P2 and four biphasic regions were revealed based on an XRD analysis. The sodium contents in these phases were determined according to the d00j-x relations …
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The effect of temperature on phase transformation mechanisms in electrodes for Li-ion batteries
… on the phase transformation mechanisms in electrodes for lithium-ion batteries (LIBs) is an important but – to date – only less studied subject in battery research. In real-life applications, LIBs usually function at non-ambient conditions and especially increased temperatures give rise …
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A Study of the Kinetics of Phase Separation in a Nickel-12.5 at.percent Silicon Alloy
The kinetic behavior of $\gamma\sp\prime$ precipitation in a supersaturated Ni-12.5 at.% Si alloy single crystal has been studied by means of in situ wide-angle x-ray diffraction (XRD), small-angle neutron scattering (SANS) and high-resolution wide-angle XRD techniques. The kinetic parameters, i.e. …
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Das Industriemineral Vermiculit - Enfluß der Rohstoffmineralogie auf die De- und Rehydratation bei der Herstellung von Hochtemperaturdämmstoffen
Vermiculite is an important clay mineral and due to its exfoliation characteristics also used for industrial processing. Over the past years crystal structure and chemistry of selected samples have been extensively investigated. But so far the in-situ investigation of temperature and humidity …
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Interrelationships of microstructure, stress and diffusion
Extensive research has been performed on thin metal films due to their interesting mechanical, electrical and magnetic properties. They can exhibit very high residual, internal stresses arising from the film growth and/or external effects. Apart from direct mechanical consequences, several …
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Investigation on the phase stability and defect structure of Li-Mn-O and Li-Me-Mn-O spinel (Me=Mg, Ni, Co)
This thesis has been an effort to interpret the defect structure of the nonstoichiometric spinel. The Li-Mn-O spinel and doped Li-Me-Mn-O (Me = Mg, Co, Ni) spinel were synthesized in modified Pechini method. The phase stability was investigated by in situ XRD, TG and DTA. A new phase diagram is put …
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The relationship between mechanical properties and microstructure of HT9 steel
… HT9, a ferritic/martensitic alloy, was used in previous fast research reactors (such as EBR-II and FFTF). However, it needs validation before it can be selected for use in the more extreme environments of Gen–IV reactors. This dissertation presents a series of in-situ high-energy synchrotron …
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Investigation of mechanical behavior of Alloy 709 for advanced fast reactor applications
… of next-generation nuclear reactor systems brings with it a multitude of material challenges. The structural materials to be used for these reactors will be exposed to more extreme conditions of radiation, stress, and temperature than those of prior generations. The development and …
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Surface studies of Li-ion and Mg battery electrodes
… battery electrodes. A fundamental understanding of processes occurring at the electrode surface is vital to the development of advanced battery systems. Additionally, modifications to the electrode surfaces are made and further characterized for improved performance. LiMn2O4 Cathodes for …
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Metal oxide supported iron-nickel nano-alloys in the reverse water-gas shift reaction
Rising atmospheric CO2 concentrations pose an existential threat to human life. The development of carbon capture and utilization (CCU) technologies which can consume CO2 at the same scale that it's being produced are necessary to limit the global mean surface temperature increase to 2 °C, in …
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Alumina-modified cobalt catalysts for the Fischer-Tropsch synthesis
In the Fischer-Tropsch process, valuable hydrocarbons are produced using the basic starting materials hydrogen and carbon monoxide, which can be derived from alternative carbon sources such as coal, gas or biomass [1]. Although this process has been studied for almost a century, the effects of the …
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Oxidative dehydrogenation of ethane with carbon dioxide over iron-nickel nano-alloys supported on metal oxide overlayers
… of ethane (CO2-ODHE) is one of the promising alternative routes for simultaneous conversion of ethane and the greenhouse gas (GHG) CO2 into high-demand monomers: ethylene and CO [1,2]. It has been extensively investigated on oxide catalysts with those based on Cr, V and Ga exhibiting high …
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Molecular Beam Epitaxy Synthesis and Characterization of Indium Selenide Films
In this thesis, synthesis and physical characterization of In2Se3 films, characterization of the effect of cooling rate on the β→α phase transition, and electrical characterization β-, γ-, and κ-In2Se3 thin-film transistors has been demonstrated. The effects of substrate temperature, substrate …
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Tensile behavior analysis on neutron irradiated Fe-Cr-C alloys using in-situ synchrotron X-ray and micromechanics modeling
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2025-12-01
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Thermodynamic and kinetic examinations of inorganic materials formation
Inorganic materials formation is the result of a complicated interplay between thermodynamics and kinetics. Improved understanding of such factors can aid the synthesis of target materials and the discovery of new materials. Here, techniques for carrying out time-resolved studies were developed and …
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Novel empowered supports for iron-based Fischer-Tropsch in a power-to-liquids process
… that converts carbon monoxide and hydrogen into liquid hydrocarbons 1 . In the past, FT synthesis has been used to produce gasoline and diesel from coal and natural gas. However, with increasing demand for renewable and sustainable energy sources, there has been renewed interest in using FT …
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Fabrication, Kinetics and Crystallography of Lithium Disilicate Glass-Ceramics
This research project mainly focuses on three aspects of investigations on lithium disilicate glass-ceramics, namely, fabrication, kinetics, and crystallography. One of the objectives is to fabricate a high-strength glass-ceramic in complex lithium disilicate glass systems for dental restorative …
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Metallic cobalt derived from cobalt nitrides for Fischer-Tropsch Synthesis
… a mixture of carbon monoxide (CO) and hydrogen, into long chain hydrocarbons, namely α-olefins and n-paraffins. The product selectivity of this reaction is dependent on the nano effects of the catalyst used in addition to the reaction conditions, making FTS a highly structure-sensitive reaction. …
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Διαφοροποίηση της μικρο/νανοπορώδους δομής πολυολεφινών στην προσπάθεια ανάπτυξης αναπνεύσιμων νοσοκομειακών μη υφασμένων προϊόντων
… ή οξειδωτική ατμόσφαιρα, με περίθλαση ακτίνων Χ (XRD), ηλεκτρονιακή μικροσκοπία σάρωσης (SEM), φασματοσκοπία Raman, ποροσιμετρία υδραργύρου και φυσιορόφηση αζώτου (BET). Ακολούθως, εξετάσθηκε η ενσωμάτωση εμπορικού CaCO3, εργαστηριακών πληρωτικών υλικών (πορώδες CaCO3, αεροπήκτωμα SiO¬2, κλπ) και …