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Monolithic Multiphysics Simulation Of Hypersonic Aerothermoelasticity Using A Hybridized Discontinuous Galerkin Method, William Paul England May 2023

Monolithic Multiphysics Simulation Of Hypersonic Aerothermoelasticity Using A Hybridized Discontinuous Galerkin Method, William Paul England

Theses and Dissertations

This work presents implementation of a hybridized discontinuous Galerkin (DG) method for robust simulation of the hypersonic aerothermoelastic multiphysics system. Simulation of hypersonic vehicles requires accurate resolution of complex multiphysics interactions including the effects of high-speed turbulent flow, extreme heating, and vehicle deformation due to considerable pressure loads and thermal stresses. However, the state-of-the-art procedures for hypersonic aerothermoelasticity are comprised of low-fidelity approaches and partitioned coupling schemes. These approaches preclude robust design and analysis of hypersonic vehicles for a number of reasons. First, low-fidelity approaches limit their application to simple geometries and lack the ability to capture small scale flow …


Physiology Of Human-Equine Interaction During Substance Withdrawal, Molly Marie Friend May 2023

Physiology Of Human-Equine Interaction During Substance Withdrawal, Molly Marie Friend

Theses and Dissertations

Psychotherapy incorporating equine interaction (PIE) is emerging as an effective treatment for substance use disorder (SUD), but research is limited concerning physiological impacts during substance withdrawal. This study investigated impacts of PIE on salivary cortisol concentrations, heart rate, anxiety, and depression during SUD withdrawal. Heart rate and cortisol concentrations were measured in horses to determine potential human-horse coupling. Saliva samples and heart rates were collected pre and post PIE from residential SUD patients (n=18) and their therapy horses (n=4) during and following the withdrawal period. Participants (n=10) also completed a survey measuring anxiety and depression (P = 0.05). A …


Versatile And Robust Non-Iterative Coupling Algorithm For Vehicle-Structure Interaction, Arya Datta Oct 2022

Versatile And Robust Non-Iterative Coupling Algorithm For Vehicle-Structure Interaction, Arya Datta

Theses and Dissertations

The dynamic analysis of the vehicle-structure interactions can be extremely computationally expensive. A general non-iterative coupling algorithm based on the substructure approach has been presented. It retains the advantage of the substructure approach that smaller subsystems are solved instead of a large system, which is usually solved when monolithic systems are solved. However, the advantage of using this general coupling approach is that it is non-iterative in nature, instead of the substructure approach that usually uses iterative procedure. The general coupling algorithm developed has been implemented to analyze dynamic interactions between the vehicle and the structure, both in two and …


Assessing Code Decay By Detecting Software Architecture Violations, Ajay Bandi Dec 2014

Assessing Code Decay By Detecting Software Architecture Violations, Ajay Bandi

Theses and Dissertations

Code decay is a gradual process that negatively impacts the quality of a software system. Developers need trusted measurement techniques to evaluate whether their systems have decayed. This dissertation aims to assess code decay by discovering software architectural violations. Our methodology uses Lightweight Sanity Check for Implemented Architectures to derive architectural constraints represented by can-use and cannot-use phrases. Our methodology also uses Lattix to discover architectural violations. We also introduce measures that indicate code decay in a software system. We conducted two case studies of proprietary systems (9 versions of System A and 14 versions of System B) to demonstrate …


Coupling Sediment Transport And Water Quality Models, Yi Xiong Dec 2010

Coupling Sediment Transport And Water Quality Models, Yi Xiong

Theses and Dissertations

Sediment has profound effects on water quality. Correspondingly, water quality modeling often needs sediment transport modeling. However, simplified descriptive sediment transport was originally employed for water quality modeling, and the linkage between sediment transport models and water quality models is less developed. Therefore, the main purposes of this study were to develop general methods of coupling sediment transport and water quality models and to improve sediment transport modeling for water quality modeling. Linkage of sediment transport and water quality was discussed and a comprehensive sediment transport literature review was conducted. SEDDEER (Sediment Deposition and Erosion), a stand-alone sediment and contaminant …


Coupling Of Autotrophic And Heterotrophic Plankton Food Web Components In The Tidal-Freshwater James River, Usa, Matthew Beckwith Apr 2009

Coupling Of Autotrophic And Heterotrophic Plankton Food Web Components In The Tidal-Freshwater James River, Usa, Matthew Beckwith

Theses and Dissertations

Empirical studies have shown that algal- and detrital-based food web components are coupled in many pelagic systems as algal carbon enhances bacterioplankton production and growth efficiencies. Such phyto-bacterioplankton coupling impacts carbon flow through plankton food webs, yet the extent of coupling is poorly understood in systems receiving large amounts of allochthonous carbon. To investigate this issue, bacterioplankton abundance (BA) and community composition were compared to chlorophyll a concentrations and phytoplankton production in the tidal-freshwater James River (VA). BA averaged 107 cells mL-1 and was significantly related to chlorophyll a, phytoplankton production, and DOC concentrations. Analysis of DOC quality using fluorescence …


Tooth Engagement Evaluation Of Involute Spline Couplings, Robert R. Robins Aug 2008

Tooth Engagement Evaluation Of Involute Spline Couplings, Robert R. Robins

Theses and Dissertations

Spline couplings are used in applications involving high torque; however, due to variations in teeth clearances, all teeth in spline couplings do not engage simultaneously, causing some of the teeth to carry a disproportionately large portion of the total load. Variations in tooth-to-tooth clearances mean the first pair of teeth to engage will carry more load and fail sooner. This has lead to an industry practice of designing splines around the criteria that only 25-50% of the teeth on a spline coupling will engage and carry the load, and the load is generally assumed to be uniformly distributed. This research …