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 “"Pre-Stress"”.
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Vowel Phonology in Russian Dialects: First Pre-Stress Syllable in Dialects Characterized by Akan'e
… checksum: fe204eca9c100713eaaef71fbfe86210 (MD5) Previous issue date: 1974
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Computational Modal Analysis of Prestressed Half Scale Generic Business Jet Substructures
… and require accurate modal models. The work presented here aims to provide insight into the techniques necessary to model business jet fuselages with prestressed skin panels through computational modal analysis of two substructures of a generic business jet design. The two substructures were …
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Stability of elastic grid shells
… depend on the deformation, or equivalently pre-stress of an initial structure. Elastic grid shells seem particularly promising as shelters, lightweight roofs, or kinetic structures. Although fundamental to the behavior of the strucure, the influence of the pre-stress on the stability of …
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Surface and interfacial waves and deformations in pre-stressed elastic materials
This thesis is concerned with the effect of pre-stress on the propagation of surface and interfacial waves in elastic materials. Following a review of the classical theory of Rayleigh and Stoneley waves for linear elastic materials we consider first the propagation of infinitesimal surface waves on …
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Investigating the neuroendocrine and hemodynamic responses to physical and psychological stress tasks and their effects on endothelial-dependent flow mediated vasodilation using a sustained stimulus
… cortisol responses to psychological and physical stress tasks with or without social evaluation. Flow-mediated dilation (FMD) with reactive hyperemia is impaired following acute stress though less is known regarding the impact of stress and cortisol on FMD with exercise induced increases in shear …
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Glulam beams strengthened with pre-stressed basalt fibres
… were either reinforced with slack basalt fibres, pre-stressed basalt fibres or with no reinforcement for comparison. The reinforcement ratio of the basalt fibres was about 0,45% of the beams cross section for both slack and pre-stressed beams. The pre-stressing was done with cambering where the …
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Dimensionamento de concreto protendido
This thesis presents comments about the International Recommendation of the C.E.B.-F.I.P./1970, on linear members of pre-stressed concrete, with constant or variable cross section, and comparisons with the Brasilian oficial specification as well. In order to acomplish this program of study a …
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Development of Pre-Stressed Retrofit Strategies for Mitigating Fatigue Cracking in Steel Waterway Lock Gate Components
… repair costs can be high. </p> <p>This thesis presents an analytical and experimental investigation into fatigue damage within common lock gate geometries, and develops fatigue mitigation strategies capable of extending gate service-life. The goal of the research program is to identify critical …
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Attachment, Personality, and Conflict Behaviors in Romantic Couples: Examining Vulnerability to Depression
<P>Major Depressive Disorder has been conceptualized from a number of theoretical perspectives. The present study aims to provide a theoretically integrated understanding of depression vulnerability. Cognitive and interpersonal theories of depressive vulnerability were considered simultaneously in …
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Attachment, Personality, and Conflict Behaviors in Romantic Couples: Examining Vulnerability to Depression
<P>Major Depressive Disorder has been conceptualized from a number of theoretical perspectives. The present study aims to provide a theoretically integrated understanding of depression vulnerability. Cognitive and interpersonal theories of depressive vulnerability were considered simultaneously in …
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Differentiation between the Effects of Physical and Psychosocial Stress on a Feedback-based Learning Task
… process in which decisions are made based on the previous feedback. This learning process is influenced by acute stress. However, different laboratory stressors elicit different physiological response patterns, which may influence feedback processing differently. Moreover, individual differences …
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Effect of Centrifugal Stiffening on the Natural Frequencies of Aircraft Wings During Rapid Roll Maneuvers
… affect the stiffness of the wings. A number of previous studies explain the effect of centrifugal stiffening in rotating beams and consequently on the frequencies of the beam. Multiple cases of the rotating beam are explored in this thesis to investigate effects of mass distribution and boundary …
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An examination of psychological stress and its effects on the mitochondrial DNA
Background: With improvements in cellular stress measurement, current findings firmly implicate mitochondrial activity in cell stress reactions. Recent studies have highlighted the effects of psychological stress on mitochondria in terms of oxidative deterioration and crisis signalling. However, …
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Yield and water-relation responses of soybeans to single and multiple periods of soil-moisture stress
… physiological and yield responses to water stress were studied in a movable weather (rainout) shelter facility at Ames, Iowa, during the summer of 1978. Soil-moisture deficits were induced in six combinations of three stress periods during reproductive growth to investigate the possibility …
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Influence of Brain Derived Neurotrophic Factor and Family History of Alcohol Dependence on Alcohol Use in Healthy Social Drinkers
… alcohol use was positively related to perceived stress levels in the Val66Met group, such that participants with higher stress levels tended to consume more alcohol. This relationship was not present in the Val66Val group. Aim 2 examined stress-related changes in serum BDNF levels. It was …
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Failure analysis of a 30kHz ultrasonic welding transducer
… high frequency mechanical vibrations and compressive pressure are applied to the plastic materials. This creates intermolecular friction within the plastic which raises the temperature high enough to reach the melting point. During high volume production in manufacturing environments, the …
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Reduced-order modelling, circuit-level design and SOI fabrication of microelectromechanical resonators
… modeling and simulation of these devices is presented. Then, a combined process flow for their simultaneous fabrication on a SOI substrate is proposed. Compact models for microresonators and switches are extracted by applying mathematical model order reduction (MOR) to the devices finite …
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Design and Fabrication of Polymer/Graphene Laminate Thin Films
… thin films under dynamic loading with different pre-tensions. The design of mechanical properties in PGLs is crucial for ensuring long-term stability and operational performance. The Young's modulus is an important mechanical parameter governed by mechanical mixing in PGLs, and better mechanical …
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The pathophysiological mechanisms underlying metamemory disruptions
… In this thesis, I investigate the role of stress as one pathway through which alterations to metacognition may arise. Emerging evidence that metacognitive deficits are common across multiple psychiatric disorder categories suggests that a transdiagnostic approach may better delineate the …
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Illinois integral abutment bridges: behavior under extreme thermal loading and design recommendations
… states. Throughout the United States, IABs are preferred over conventional bridge construction because they are generally cheaper and easier to construct; have lower maintenance costs due to reduced damage to bearings, expansion joints, and other conventional appurtenances; and will …