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 150 for “"Oxide layer"”.
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Effect of a derivatized oxide layer and environment on the bond durability of aluminum/polyimide and titanium/polyimide bonds
A surface pretreatment for aluminum and titanium involving the reaction of phosphonic acid (RPO(OH)2), R=butyl or vinyl for aluminum and R=vinyl for titanium, has been investigated. The durability of phosphonic acid-pretreated samples was compared with that for P2-etched (ferric sulfate-sulfuric …
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Optoelectronic characterization of wide-bandgap (AgCu)(InGa)Se 2 thin-film polycrystalline solar cells including the role of the intrinsic zinc oxide layer
… sheet resistance of the high resistance (HR) ZnO layer in polycrystalline thin film (AgCu)(GaIn)Se2 (ACIGS) solar cells. The effect of varying these parameters on the electric field distribution, depletion width and hence capacitance were studied by SCAPS simulation. Devices were then fabricated …
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Synchrotron X-Ray Diffraction and Piezospectroscopy used for the Investigation of Individual Mechanical Effects from Environmental Contaminants and Oxide Layer Undulations in Thermal Barrier Coatings
… Zirconia Topcoat (YSZ) and Thermally Grown Oxide (TGO) strain in sprayed Thermal Barrier Coating (TBC) samples of varying porosity with and without CMAS ingression. In-Situ Synchrotron X-ray Diffraction measurements were taken on the sample under thermal loading conditions from which the YSZ …
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Impedance spectroscopy response of aluminum-copper-silicon alloys
… heat treatment on the polarization resistance, oxide-layer/double-layer capacitance, open circuit potential and breakdown potential of Al-Cu-Si alloys was evaluated. Electrochemical impedance spectroscopy and DC polarization techniques were combined with mechanical property evaluations to …
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Flow Effects Upon the Repassivation of Iron and Cobalt in Neutral and Acidic Solutions
… mechanism by which metal reforms a protective oxide layer after removal though erosion or other mechanical means, experiments were performed in a specially designed flow cell. Particle impaction and subsequent depassivation were simulated through amperometric reduction of the oxide layer. …
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Local Charging Behavior on GaN Surfaces
… preparation and the presence of a surface oxide layer. If a substantial oxide layer exists, then both positive and negative charging is possible on n-type and p-type samples. Surface treatments and photoemission spectroscopy (XPS) data confirm the presence and influence of the oxide layer …
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Development of a 3D Printer for Oxide-free Aluminum Transportation
… when exposed to air aluminum forms an inert oxide layer on its surface, preventing reaction. High reaction temperatures are required to overcome the oxide layer leading to a high energy penalty. This thesis proposes a novel concept of aluminum encapsulation with water-soluble polymer. A 3d …
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Aspects of the oxidation of liquid aluminium alloys.
… by the diffusion of species through thick oxide scales, but by the strength and the deformation characteristics of the oxide skin, and by the short-time oxidation rate of the molten aluminium. The deformation behaviour of the oxide layer covering liquid molten aluminium alloys was …
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Water based adhesive primers on aluminum substrates
… effects of the thickness of both the aluminum oxide surface layer and the primer layer on bond durability were established. 5052 aluminum alloy was oxidized by phosphoric acid anodization prior to primer coating. The oxide layer thickness was controlled mainly by changing anodization voltage …
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Oxidation behavior of very high temperature reactor (VHTR) candidate materials: 316l stainless steel, Alloy 617, and Incoloy-800H
… at 873 K to 1273 K. At 773 K, a thin external oxide layer was observed, while at higher temperatures a continuous and relatively irregular and inwardly protruded external oxide layer was observed. The external layer width and composition depended on increasing temperatures. At 1073 K a Cr2O3 …
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Optimization of surface preparation technique for unipolar silicon direct bonding
… wafers is given to ensure a minimized amount of oxide layer on the surface. Several key factors that govern the quality of the wafer surfaces, such as the degree of hydrophobicity, HF etching time, composition of HF etching solution and Dr water rinse, are examined with ellipsometric and XPS …
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Substrate cleaning using a remote hydrogen rf-plasma
… used in semiconductor processing have a surface oxide layer (the so-called native oxide layer) and a hydrocarbon contamination layer that must be removed before growing an epitaxial film of good quality. In this work, low temperature remote rf-hydrogen plasma cleaning of II-VI and silicon …
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Metal oxide/organic interface investigations for photovoltaic devices
This thesis outlines investigations of metal oxide / organic interfaces in photo- voltaic devices. It focuses on device instabilities originating from the metal oxide layer surface sensitivity and it presents suggested mechanisms behind these in- stabilities. A simple sol-gel solution deposition …
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Suspended Gate Silicon Nanodot Memory
… of devices and systems from pen drives, mp3 players to cars, planes and satellites. However,the conventional floating gate memory technology in use for flash memory is facing a serious scalability issue, the tunnel oxide thickness cannot be reduced to less than 7nm as pointed out in the latest …
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In-situ investigation of the oxidation kinetics of Fe-12Cr-2Si using time-resolved transient grating spectroscopy
… kinetics of Fe-12Cr-2Si, a model alloy with oxide layer formation properties similar to large classes of Fr-Cr alloys. By monitoring the effect of thin oxide layers on surface thermal transport, there exists a pathway to continuously determine the thickness of a tens of nanometers thick …
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The effect of moisture exposure on pretreated aluminum alloys
… times of exposure to water. The thickness of the oxide layer was found to increase with time of exposure to water based on ESCA results. The same conclusion was reached by depth profiling the oxide layer using AES. The rate of increase in the concentration of pseudoboehmite on the surfaces as …
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Titanium dioxide dielectric layers made by anodization of titanium: the effect of dissolved nitrogen and oxygen
… the Ti substrateon the formation of the anodic oxide and its properties, particularly the leakage currentdensity. The best diffusion treatment condition to decrease the leakage current densityfor Grade 1 Ti was found to be infusion at 1133 K (860 °C) for 22 ks. Under this condition, nitrogen and …
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The influence of molybdenum and vanadium on the activity and selectivity of a cobalt Fischer-Tropsch catalyst
… on CO hydrogenation indicates that molybdenum oxide and vanadium oxide used as a promoter may be beneficial for the activity and selectivity of a cobalt based catalyst. To eliminate the structural influence on the selectivity by using commercial MoO3 and V2O5 supports, and alumina support was …
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Effects of flux application and melting parameters in investment casting of pure aluminium by in-situ melting technique
… as a result of the entrainment of the surface oxide (Al2O3) film known as bifilm. Currently, turbulence free filling system was applied in casting process using tilt casting, bottom filling integrated with low pressure and also in-situ casting or in-situ melting techniques to address the …
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Oxidation kinetics of metallic powders
… oxidation of aluminum covered by a thin natural oxide layer in oxygen occurring at relatively low temperatures is quantitatively characterized using different types of thermo-gravimetric (TG) measurements with increased amount of powder for greater sensitivity. Activation energy and the …
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