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 21 for “"HCF"”.
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Use of Nonlinear Volterra Theory in Predicting the Propagation of Non-uniform Flow Through an Axial Compressor
… integrity through means of high cycle fatigue (HCF). HCF is a primary mechanism of blade failure caused by vibrations at levels exceeding material endurance limits. Previous research has shown total pressure distortions to be the dominant HCF driver in aero engines, and has demonstrated the …
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An Experimental Study on Soil Water Characteristics and Hydraulic Conductivity of Compacted Soils
… (SWCC) and hydraulic conductivity function (HCF) are vital soil properties that govern engineering behavior of unsaturated soils. In this study, a transient water release and imbibitions method (TRIM) is used to measure the SWCC and HCF under drying and wetting states, which accommodates …
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Development of optimized core design and analysis methods for high power density BWRs
… simulated transients. Helical Cruciform Fuel (HCF) rods were proposed in prior MIT studies to enhance the fuel surface to volume ratio. In this work, higher fidelity models (e.g. CFD instead of subchannel methods for the hydraulic behaviour) are used to investigate the resolution needed for …
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High-cycle fatigue / low-cycle fatigue interactions in Ti-6Al-4V
… has been attributed to high cycle fatigue (HCF). Additionally, both high-cycle fatigue (HCF) and lowcycle fatigue (LCF) loadings are widely recognized as unavoidable during operation of these components and because the classic Linear Damage Rule (LDR) neglects to account for the synergistic …
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Prediction of Inlet Distortion Transfer Through the Blade Rows in a Transonic Axial Compressor
… structural integrity through high cycle fatigue (HCF) induced by the excitation of blade vibratory modes. As previous research has shown total pressure distortion to be the dominant HCF driver in aero engines [Manwaring et al, 1997], an understanding of its transfer through, and impact on, …
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A study of fretting fatigue in aircraft components
… subject to fretting contact high cycle fatigue (HCF) via a Coffin-Manson type relation. Design and construction of an apparatus for performing quantitative fretting experiments are described, and results of early tests performed on 7075-T6 aluminum alloys are presented. These experiments …
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Fatigue Damage and Small Crack Growth During Biaxial Loading
… amplitudes, one in the high cycle fatigue (HCF) region and one in the low cycle fatigue (LCF) region were employed in this study for all loading patterns. The test program included constant amplitude loading and variable amplitude loading. Two types of variable loading patterns, step loading …
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The effects of abrasion on liquid-fabric interaction of selected nonwoven fabrics
… cotton fabric with a fluorochemical finish (HCF), a hydroentangled cotton fabric laminated with a microporous film (HCE), a spunbonded polypropylene with microporous film (PSM), a four layer laminated nonwoven including spunbonded polypropylene, microporous film, hydroentangled cotton layer, …
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Modal Response of a Transonic Fan Blade to Periodic Inlet Pressure Distortion
… that can ultimately lead to high cycle fatigue (HCF), which in turn can quickly cause partial damage to a single blade or complete destruction of an entire compressor blade row, leading to catastrophic failure of the gas turbine engine. A better understanding and prediction of vibratory blade …
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High Cycle Fatigue Simulation using Extended Space-Time Finite Element Method Coupled with Continuum Damage Mechanics
High cycle fatigue (HCF) is a failure mechanism that dominates the design for many engineering components and structures. Surface treatments such as laser shock peening (LSP), ultrasonic nanocrystal surface modification (UNSM) and many others introduce significant residual stresses in the material, …
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Ermüdungs- und Rissfortschrittsverhalten ausscheidungshärtbarer ultrafeinkörniger Aluminiumlegierungen
… in den Bereichen der hochzyklischen (HCF) und niedrigzyklischen (LCF) Ermüdung sowie des Rissfortschritts untersucht. Im Mittelpunkt steht dabei die Identifikation der mikrostrukturell wirksamen Mechanismen bei der Entstehung und Ausbreitung von Ermüdungsrissen. Es werden ein homogen …
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Distributed household effects of climate policy in the United States
… model of the household carbon footprint (HCF) for an average household in each US Census tract. Policy outcomes were assessed by quantifying the net increase or decrease of annual household expenses (e.g.
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Understanding tetratricopeptide repeats of <i>O</i>-GlcNAc transferase
… regulator protein host cell factor-1 (HCF-1). OGT contains an N-terminal tetratricopeptide repeat (TPR) domain, with some evidence to suggest that this domain plays a role in substrate and adaptor protein binding. However, our understanding of the mechanisms underlying OGT substrate …
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The microstructure and properties of powder HIPped nickel-based superalloy CM247LC
… as-HIPped specimens had the best tensile and HCF fatigue properties at both room temperature and 750 °C; the influence of post-HIP solution treatment conditions and of subsequent ageing on the properties of samples which had been HIPped at 1260 °C was thus investigated. A solution treatment at …
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Forced response of a centrifugal compressor stage due to the impeller-diffuser interaction
… failure, better known as a high cycle fatigue (HCF) failure. This thesis seeks to identify the physical mechanisms that set the forced response amplitude of an impeller due to the impeller-diffuser interaction. The centrifugal stage researched is comprised of a stationary discrete passage …
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Cyst morphology and serological variation in cystic echinococcosis patients from Turkana, Kenya
… antibody in response to HSP70, EgEF-1β/δ and HCF. The best diagnostic tool was found to be expression of IgG1 in response to TPx which showed sensitivity of 95%. In follow-up, responses of total IgG towards AgB was found to be useful. It increased in all recurring cases, decreased in all …
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Étude des recouvrements avec effet de barrière capillaire pour minimiser les infiltrations d'eau dans les sites d'enfouissement de matières résiduelles
… (WRC) and the hydraulic conductivity functions (HCF) of materials are fundamental. The design procedure included optimization of the thicknesses of the several layers composing the barrier and determination of the transfer length (TL) using an appropriate model. The latter had to be shorter than …
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Adaptable Spatial Agent-Based Facility Location for Healthcare Coverage
… and morbidity. Public healthcare facilities (HCFs) are expected to be located such that they can be reached within reasonable distances of the patients’ locations, while at the same time providing complete service coverage. However, complete service coverage is generally hampered by resource …
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Evaluating localized electrochlorination systems as a low-cost means of producing potable water
… A pilot evaluation in 26 Healthcare facilities (HCF) from Burkina Faso focusing on usability, cost-effectiveness, and sodium hypochlorite concentration compared outcomes with a control group. At a later stage, in 68 HCFs from Chad, impacts on Water, Sanitation, and Hygiene (WASH) indicators, …
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Design of a Total Pressure Distortion Generator for Aircraft Engine Testing
A new method and mechanism for generating non-uniform, or distorted, aircraft engine inlet flow is being developed in order to account for dynamic changes during the creation and propagation of the distortion. Total pressure distortions occur in gas turbine engines when the incoming flow is …
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