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 13 of 13 for “"Degradation Modes"”.
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Degradation modes of the top-side contacting of SiC power semiconductors
… bond interconnections and to better understand degradation mechanisms. In the Al module, thermomechanical stresses led to bond wire lift-off, with cracks starting at the bond foot and spreading along the bond interface due to the coefficient of thermal expansion (CTE) mismatch between aluminum …
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Impedance model of a solid oxide fuel cell for degradation diagnosis
… the possibilities to diagnose and identify degradation mechanisms in a minimally invasive way using impedance spectroscopy. This is the first report of an SOFC impedance model to incorporate degradation, as well as the first one to include the ribbed interconnect geometry, using a 2-D …
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DEVELOPMENT AND OPTIMIZATION OF BACK SURFACE ACRYLICSOLARMIRRORS TO ASSURE 25 YEAR LIFETIME PERFORMANCE
… long periods, may result in premature degradation or outright failure; howevermanyunproven material systems have not been evaluated for their lifetime performance. Inaddition, they can present opportunities to reduce system costs without negatively impactingperformance. Lifetime and …
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Lifetime prediction for lithium-ion batteries undergoing fast charging protocols
… of the inverse problem, the attribution of degradation modes, and the accuracy of parametric power-law lifetime predictions. Multiphase Porous Electrode Theory (MPET) is also explored in this thesis. In MPET, each particle of the porous electrode ensemble is described by generalized …
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Concrete deterioration inspection system for extending the operating life of nuclear power plants
This study has evaluated the degradation processes which will potentially affect the reinforced concrete structures of a nuclear power generation facility during and beyond its original design life. This task was undertaken in consideration of the feasibility of extending the life of nuclear power …
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Non-destructively detecting spinodal decomposition at a distance towards developing gigahertz ultrasonics for in-vessel inspection
… of their structural components to environmental degradation. In particular, critical components for light water reactors (LWRs) evolve over decades in service, losing ductility and toughness due to thermal and irradiation aging. Techniques to monitor their health cannot be easily applied in the …
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Inspection of Ferromagnetic Support Structures From Within Alloy 800 Steam Generator Tubes Using Pulsed Eddy Current
… induced currents. However, when multiple degradation modes are present simultaneously near ferromagnetic materials, such as tube fretting, support structure corrosion, and magnetite fouling, ECT reliability decreases. Pulsed eddy current (PEC), which induces transient eddy currents via …
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Impact of electrochemical process on the degradation mechanisms of AlGaN/GaN HEMTs
… on understanding the physics behind various degradation modes and providing new quantitative models to explain these mechanisms. The first part of the thesis, Chapters 2 and 3, reports studies of the origin of permanent structural and electrical degradation in AlGaN/GaN HEMTs. Hydroxyl groups …
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Structure-Property Relationships of Alicyclic Polyesters
… polymer to thermal, hydrolytic, and oxidative degradation during melt processing. The various degradation modes result in a drop in molecular weight, loss of key physical properties, and release of volatile compounds. Furthermore, the vast issue of plastic accumulation and pollution in diverse …
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In-situ impedance characterization for assessing SiC MOSFETs reliability
… on-state resistance correlates with gate-oxide degradation, while bond-wire lift-off leads to a measurable increase in package inductance. The circuit is thus capable of simultaneously tracking both degradation modes. Its performance is validated through extensive experimental setups including …
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Linear and Nonlinear Electrochemical Impedance Spectroscopy for Lithium-ion Batteries
… NLEIS and EIS are able to characterize early degradation (< 1% capacity loss) in commercially available (1.5 Ah LiNMC|C) batteries. While NLEIS shows that fresh cells have high symmetry charge transfer (α<sub>a</sub> = α<sub>c</sub> = 0.5), a shift toward kinetics that favor oxidation on the …
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Developing durable electrodes for selective electroreduction of CO2 to value-added intermediates
… mA cm–2). In addition, Chapter 2 discusses the degradation mechanisms that plague various ECO2RR cells and cause their eventual failure and short durability. Common degradation modes include catalyst agglomeration, carbonate formation, and binder dissolution. This chapter concludes by proposing …
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Viability under adversity: Safe self-organizing control of systems in the unknown
Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2025-03-28 without embargo terms