Theses and Dissertations at Montana State University (MSU)
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Item Magnetic resonance imaging studies of forced and free convective heat transfer in packed beds and fluid columns(Montana State University - Bozeman, College of Engineering, 2021) Skuntz, Matthew Eric; Chairperson, Graduate Committee: Ryan Anderson; This is a manuscript style paper that includes co-authored chapters.Prediction of fluid flow and associated energy transport is an essential component in many engineering applications where analytical solutions are not possible. In these systems experimentation and numerical simulations are a necessary part of the design process. This work focuses on the experimental study of mass and energy transport in packed beds and pure fluids under forced and natural convection using nuclear magnetic resonance (NMR) imaging (MRI) techniques. It further evaluates the efficacy of commercial computational fluid dynamics (CFD) software to simulate these processes. The study of heat transfer via NMR has proven difficult historically, despite sensitivity of NMR parameters to temperature. Here, a novel experimental setup is pioneered, which enables the study of heat transfer in packed beds. The method employs fluorinated pore-filling fluid and hydrogen-rich core-shell packing particles. Hydrogen and fluorine are NMR-active chemicals that can be imaged with the same experimental equipment by adjusting the resonance frequency; providing means to image the two domains separately. Pore- fluid velocities and particle-wax melting are observed in the same packed bed, at sub-millimeter resolutions, presenting a more complete picture of the conditions in these hard-to-measure systems. In the presented studies, this methodology is demonstrated under forced convection and proven capable in identifying and correlating spatial variations in heat transfer to pore-fluid velocity. The technique is then employed to assess the accuracy of a CFD model in the commercial software package, STAR CCM+, using the melt to quantify energy absorbed by the bed. In natural convection studies of a pure fluid and packed bed in the Rayleigh-Bénard configuration, the axial circulation pattern is found to change with axial position in the long narrow cylinder, a result that is rarely discussed in literature. A CFD model is shown to match well with these experimental findings. In porous media convection with sub-, near- and super- critical fluid, the rapidly changing thermal diffusivity was captured by the rate the particles absorb energy. Finally, a correlation is developed allowing particle-wax T 2 relaxation time to be converted into temperature.Item Nuclear magnetic resonance studies to characterize phase transitions in porous systems(Montana State University - Bozeman, College of Engineering, 2018) Thrane, Linn Winsnes; Chairperson, Graduate Committee: Sarah L. Codd; Emily A. Berglund, James N. Wilking, David Vodak and Joseph D. Seymour were co-authors of the article, 'NMR relaxometry to characterize drug structural phase in a porous construct' in the journal 'Molecular pharmaceutics' which is contained within this thesis.; Sarah L. Codd and Joseph D. Seymour were co-authors of the article, 'Probing molecular dynamics during hydrate formation by high field NMR relaxometry and diffusometry' submitted to the journal 'Journal of magnetic resonance' which is contained within this thesis.; Ryanne L. Daily, Abby Thane, Catherine M. Kirkland, Evan R. McCarney, Robin Dykstra, Sarah L. Codd and Adrienne J. Phillips were co-authors of the article, 'Detecting microbially induced calcite precipitation in porous systems using low-field nuclear magnetic resonance relaxometry' submitted to the journal 'Environmental science & technology' which is contained within this thesis.Nuclear magnetic resonance (NMR) allows for in-situ non-invasive studies of a wide range of systems at microscopic time and length scales. NMR relaxometry and diffusometry techniques along with magnetic resonance imaging (MRI) are applied to explore and characterize various phase transitions in complex systems. NMR techniques are highly sensitive to the thermodynamic phase of the system as well as restrictions on molecular motion, and the ability to detect and monitor phase transitions non-invasively is of great interest for various industrial applications NMR frequency spectra and 1D T 2 relaxation measurements are used to characterize the presence of an amorphous drug and its liquid-solid phase transition. T 1- T 2 magnetic relaxation correlation experiments monitor the impact of long-time storage at high relative humidity on the drug in a porous silica tablet. The results indicate the ability of non-solid-state NMR to characterize crystalline and amorphous solid structural phases, and the potential for drug quality control by NMR methods. High resolution MRI along with T 1-T 2 magnetic relaxation correlation experiments and pulsed gradient stimulated echo (PGStE) NMR methods are demonstrated to characterize hydrate formation. MRI monitors the spatial heterogeneity of the system as well as local hydrate growth rates. Using T 1-T 2 correlation NMR and spectrally resolved diffusometry, the transition from mobile to restricted dynamics is observed simultaneously for both water and cyclopentane throughout the hydrate formation process. The combination of these MR techniques allows for exploration of the complex molecular dynamics involved in hydrate formation processes. Using a low-field NMR system, microbially induced calcite precipitation (MICP) processes in granular media are explored by means of 1D T 2 relaxation measurements. The 1D T 2 distributions allowed for in-situ monitoring of the mineral precipitation progress and indicates decrease in total pore volume and a significant change in the surface mineralogy of the granular media. The results confirm the potential for detailed characterization of MICP progression in engineering applications. Ultimately, NMR is demonstrated as an effective method for detecting, characterizing, and monitoring several distinct phase transitions at various time- and length-scales.Item Diffusion and diffusive exchange are sensitive to the structure of cartilage as measured by nuclear magnetic resonance(Montana State University - Bozeman, College of Engineering, 2017) Mailhiot, Sarah Elizabeth; Chairperson, Graduate Committee: Ronald K. June II; Nathan H. Williamson, Jennifer R. Brown, Joseph D. Seymour, Sarah L. Codd and Ronald K. June were co-authors of the article, 'T1-T2 correlation and biopolymer diffusion within human osteoarthritic cartilage measured with nuclear magnetic resonance' in the journal 'Applied magnetic resonance' which is contained within this thesis.; Sarah L. Codd, Jennifer R. Brown, Joseph D. Seymour and Ronald K. June were co-authors of the article, 'Pulsed gradient stimulated echo (PGSTE) NMR shows spatial dependence of fluid diffusion in human stage IV OA cartilage' submitted to the journal 'Magnetic resonance in medicine' which is contained within this thesis.; Fangrong Zong, James E. Maneval, Ronald K. June, Petrik Galvosas and Joseph D. Seymour were co-authors of the article, 'Quantifying NMR relaxation correlation and exchange in articular cartilage with time domain analysis' submitted to the journal 'Journal of magnetic resonance' which is contained within this thesis.; James E. Maneval, Ronald K. June and Joseph D. Seymour were co-authors of the article, 'Relaxation exchange in human OA cartilage impacts the observable T 2 relaxation rates' submitted to the journal 'Magnetic resonance in medicine' which is contained within this thesis.Osteoarthritis (OA) is the deterioration of the tissue on the surface of the articulating joints in mammals. OA is the progression loss of articular cartilage. OA affects 50% of people over age 65 and is the leading cause of workplace disability. There is no cure for OA and the state of the art treatment is joint replacement. One limitation for treating OA is the difficulty of diagnosing OA before tissue failure. Magnetic Resonance Imaging (MRI) is capable of detecting early pathologic changes to cartilage but challenges remain. The goal of this work is to evaluate how parameters, specifically relaxation and diffusion, used for creating imaging contrast in MRI are affected by disease in naturally occurring human osteoarthritis. Nuclear Magnetic Resonance (NMR) is utilized to measure the diffusion and magnetic relaxation in human OA cartilage samples. Diffusion Weighted Imaging (DWI) is a proposed imaging mechanism for diagnosing OA. The hypothesis is that fluid diffusion is faster in diseased tissue than in healthy tissue. We show that diffusion of fluid increases when cartilage is damaged by enzymes, such as during OA. We also show that the diffusion of fluid is donor specific in human OA cartilage. Diffusion of proteins in cartilage is also sensitive to enzyme degradation and donor as well as to the size and structure of the proteins in cartilage. These are complementary measures of the fluid and solid phase of cartilage. Relaxation weighted imaging is the most common way to image cartilage and is capable of measuring small structure changes due to OA. One limitation of this method is that reported relaxation rates vary between studies. We show that exchange, or motion of fluid, between the two sites of relaxation in cartilage alters the observed relaxation. Further, we show that the exchange rate is sensitive to donor and enzyme degradation. The results suggest that exchange rate is a sensitive measure of structure in cartilage and that relaxation should be cautiously interpreted when exchange occurs. Overall, this work shows that NMR and MRI are sensitive to the structure of cartilage and capable of detecting pathological damage to cartilage.