Theses and Dissertations at Montana State University (MSU)
Permanent URI for this communityhttps://scholarworks.montana.edu/handle/1/732
Browse
57 results
Search Results
Item Power and perils of partnership: a lifecycles approach to understanding barriers to data use in Montana volunteer water monitoring programs(Montana State University - Bozeman, College of Letters & Science, 2022) Bean, Liam Francis; Chairperson, Graduate Committee: Sarah P. ChurchAs socionatural systems become more unpredictable due to increased anthropogenic interference, the need for responsive data-driven governance is apparent. However, there is a repeated assertion that public trust in science and the scientific process is eroding. Public participation in scientific research, or citizen science, is often seen as a pathway to rebuilding public trust in data collection and analysis while also being an effective cost-cutting measure as research funding becomes more and more difficult to secure. I developed case studies of five different volunteer water monitoring programs from across the state of Montana. Each case was primarily constructed from semi-structured interviews with various volunteers, program managers, and decision-makers. These cases explore how trust in volunteer water quality data was generated across stakeholder groups and if, and how, volunteer collected data are used in local governance processes. To explore the relationship between different volunteers, program managers, tributaries, monitoring equipment, and decision-makers, an approach inspired by actor network theory was adopted during the analysis. The five cases all had key parallels in their histories and while each case was distinct, all five seemed to pass through similar phases I describe as a generalized lifecycle. The four key phases of this lifecycle were: 1) an inciting incident, 2) enrollment of allies, 3) re-enrollment of allies, and 4) program evaluation. The second and third phases were key to understanding how data produced by volunteers would eventually be used. When programs enrolled alongside state actors like the Montana Department of Environmental Quality, volunteers and local community members saw decision-making processes as more legitimate, and volunteer water monitoring programs had a direct route to having their data used. However, the process of being enrolled alongside a different monitoring program or state agency created a problem with the salience of volunteer collected data, often making it less reflexive to community needs and less used in local governance processes. In addition, regular re-enrollment with new agencies, partners, and monitoring efforts allowed many programs to secure funding and paths to data use but hampered their ability to produce datasets for long-term trend analysis.Item Design and fabrication of membrane-based pressure sensor for capillary pressure measurement in micromodels(Montana State University - Bozeman, College of Engineering, 2021) Raventhiran, Nishagar; Chairperson, Graduate Committee: Yaofa LiPressure is a fundamental quantity in virtually all problems in fluid dynamics from macro-scale to micro/nano scale flows. Although technologies are well developed for its measurement at the macro-scale, pressure quantification at the microscale is still not trivial. Yet, precise pressure mapping at microscale such as in microfluidics is imperative in a variety of applications, including porous media flows and biomedical engineering. In particular, pore-scale capillary pressure is a defining variable in multiphase flow in porous media and has rarely been directly measured. To that end, this study aims to design and fabricate an on-chip sensor that enables quantification of capillary pressure in microfluidic porous media, called micromodels. The micromodel is fabricated in polydimethylsiloxane (PDMS) using soft lithography with a thin membrane incorporated that deflects with pressure variations in the fluid flow. Employing a microscope coupled with a high-speed camera and the astigmatism particle tracking principle, precise pressure measurement is achieved with an accuracy of ~ 60Pa. This sensor is then applied to characterize the viscous pressure drop in single phase flows, and the capillary pressure in a water-air multiphase in microchannels, and good agreement is obtained between the sensor measurement, theoretical values and measurements employing a commercial pressure transducer. This thesis provides a novel method for in-situ quantification of local pressure and potentially 2D pressure field in microfluidics and thus opens the door to a renewed understanding of pore-scale physics of multiphase flow in porous media.Item Towards a precision measurement of the Newtonian constant of gravitation and accelerometry with a levitated microsphere in a magneto-gravitational trap(Montana State University - Bozeman, College of Letters & Science, 2020) Lewandowski, Charles Wayne; Chairperson, Graduate Committee: Brian D'UrsoSince the theory of gravity was published by Issac Newton in the seventeenth century, scientists have studied its strength, originally for the purpose of astronomy and measuring the density of the Earth. After centuries of research and measurements, G remains the least precisely known fundamental constant. A new method for a time-of-swing measurement of G, developed a the National Bureau of Standards 1930, is proposed using a levitated microsphere in a magneto-gravitational trap. A new magneto-gravitational trap based on a previous system from our laboratory has been developed for a measurement of G. This trap has been designed to load large particles with low oscillation frequencies with large amplitudes of motion to improve sensitivity to G. Because of the weak trap, a loading method has been developed utilizing electric fields to help balance the force of gravity. A stable and variable high voltage reference has been developed to provide the necessary electric field. Camera-based feedback control has been implemented for cooling the center-of-mass motion or heating the motion in a controlled way. To limit errors due to equilibrium shifts of the particle in the trap from tilt, a simple modification was made to an optical table to actively stabilize the tilt. A measurement of G requires high sensitivity to accelerations and forces. The parameters achieved towards the measurement of G makes this system sensitive to acceleration. The first direct use of a room temperature levitated optomechanical system as an accelerometer has been achieved, with the best sensitivity to accelerations of any room temperature levitated optomechanical system. The sensitivity was measured to be 3:6 x 10 -8 g / square root of Hz.Item Statistical methodology for biological signals in the presence of measurement uncertainty(Montana State University - Bozeman, College of Letters & Science, 2018) Barbour, Christopher Robert; Chairperson, Graduate Committee: Mark Greenwood; Bibiana Bielekova (co-chair); Mark Greenwood, Dominique Zosso and Bibiana Bielekova were co-authors of the article, 'Constructed composite response: a framework for constructing targeted latent variables' submitted to the journal 'Biometrika' which is contained within this dissertation.; Christopher Barbour, Mark Greenwood, Dominique Zosso and Bibiana Bielekova were co-authors of the article, 'Extending CCR methodology to high-dimensional data to develop a sensitive clinical endpoint for multiple sclerosis' submitted to the journal 'Computational and graphical statistics' which is contained within this dissertation.; Peter Kosa, Mika Komori, Makoto Tanigaw, Ruturaj Masvekar, Tianxia Wu, Kory Johnson, Panagiotis Douvaras, Valentina Fossati, Ronald Herbst, Yue Wang, Keith Tan, Mark Greenwood and Bibiana Bielekova were co-authors of the article, 'Molecular-based diagnosis of multiple sclerosis and its progressive stage' in the journal 'Annals of neurology' which is contained within this dissertation.In recent years, increasing amounts of complex biological data are being collected on patients in many branches of medical research. Many of these signals are being collected with a certain amount of imprecision in the attained measurements. Two such areas in multiple sclerosis (MS) research are clinical scale development and proteomics analysis. Scales are often constructed from multiple outcome measures to create a combined metric that is a better measure of the true trait of interest than any of the original components. When the interest is in creating a scale that is sensitive to changes over time, developing it using cross-sectional data may not tune the projection to detect changes over time optimally. The proposed methodology, coined the Constructed Composite Response (CCR), was developed to maximize detected longitudinal change. A simulation study, and analysis of a motivating dataset, demonstrated that the CCR methodology performs better at capturing longitudinal change than traditional techniques. Including sparsifying constraints, motivated by penalized regression models, improved the performance of the CCR in high- dimensional data. In proteomics data, undesirable sources of variation are often present. Examples include temporal fluctuation in control samples and technical variability from multiple assay runs. When developing a molecular classifier of MS, a novel variable screening procedure was implemented to eliminate proteins with high levels of these unwanted sources. A simulation study compared this with traditional screening approaches and findings are discussed. Future extensions and directions of research are also discussed.Item Developing a load acquisition system for a multiaxial test frame(Montana State University - Bozeman, College of Engineering, 2019) Carpenter, Aaron James; Chairperson, Graduate Committee: David A. MillerMaterial testing has traditionally been completed by using a uniaxial load frame which isolates a single stress component. Engineers however, design components for applications in a multi-axial world to withstand stress in multiple directions. The In-Plane Loader (IPL) at Montana State University expands the realm of material testing to three degrees of freedom within a two-dimensional plane. Applications of the IPL include composite material testing and experimental validation of constitutive models in multiple axes. The multi-axial test frame has been in place at MSU for several years. One of the primary challenges associated with the IPL is its ability to accurately measure multi-axial load components. The purpose of this work was to develop and validate an updated multi-axial load acquisition system for the IPL. The procedure included design, manufacture, implementation, and validation of the system. Validating the system in multiple axes required isolating single stress components along each of the planar axes. Tension tests were completed to isolate the vertical component, and shear tests were completed to isolate the horizontal component. Each of the results were compared to results of standardized test procedures designed to isolate their respective stress components. Digital image correlation was implemented as a non-contact method of measuring displacement for the testing procedures. The data collected in this study provides confidence in the ability to measure multi-axial loading in combination with digital image correlation to expand the capabilities of multi-axial testing. The system provides the ability to study load dependent failure of materials as well as displacement dependent failure. The information presented provides an understanding of challenges associated with multi-axial testing which hopes to assist in the development of future multi-axial test frames.Item Measuring methane emissions from American bison (Bison bison L.) using eddy covariance(Montana State University - Bozeman, College of Agriculture, 2019) Cook, Adam Anderson; Chairperson, Graduate Committee: Paul C. StoyAmerican bison (Bison bison L.) have recovered from the brink of extinction over the past century. Bison offer potential environmental benefits as they re-occupy their native range, but many specific impacts of bison reintroduction are not well understood. Methane emissions are known to be a major climate impact of ruminants, but few measurements for bison exist due to challenges caused by their mobile grazing habits and safety issues associated with direct measurements. Here, we measure the methane and carbon dioxide fluxes from a bison herd on winter range using the eddy covariance technique. Methane emissions were negligible (mean = 0.0024 micromole m -2 s -1, SD = 0.0102 micromole m -2 s -1) before and after bison grazed in the area sampled by the eddy covariance flux footprint with the exception of a single spike possibly attributable to thawing soil or the presence of white-tailed deer (Odocoileus virginianus Z.). Methane fluxes when bison were present in the study area averaged 0.041 micromole m -2 s -1 (SD = 0.046 micromole m -2 s -1), similar to previous measurements over sheep and cattle pastures, but with little diurnal pattern due to a lack of consistent bison movement habits over the course of each day. An eddy covariance flux footprint analysis coupled to bison location estimates from automated camera images calculated methane flux with a median of 56.5 micromole s -1 per animal and a mean of 91.6 micromole s-1 per animal, approximately 50 and 75% of established emission rates for range cattle, respectively. Eddy covariance measurements are a promising way to measure methane and carbon dioxide flux from large ruminants on native range and we recommend comparisons amongst alternate grazing systems to help identify management strategies that are cognizant of climate.Item Improving measurement accuracy during science experiments with fourth grade students(Montana State University - Bozeman, College of Letters & Science, 2018) Eichner, Samantha; Chairperson, Graduate Committee: Walter WoolbaughThis action research study measured fourth grade students' length measurement accuracy on performance assessments and science experiments before and after treatment. The purpose of the treatment was to determine whether meaningful practice would improve students' accuracy. Students' measurement accuracy on science experiments and performance tasks was recorded along with observations, interviews, and surveys. To determine which system they were most accurate in, students measured in both the English and metric systems. The results suggest that with practice students can make notable gains and record fewer unreasonable answers.Item The elastic properties of bone by ultrasound(Montana State University - Bozeman, College of Engineering, 1985) LaMont, Donald Thompson; Chairperson, Graduate Committee: Michael K. WellsItem Compressive laser ranging with embedded systems(Montana State University - Bozeman, College of Engineering, 2015) Pandit, Pushkar Pradeep; Chairperson, Graduate Committee: Joseph A. ShawCompressive sensing is a signal processing technique that has recently come to the forefront due to its ability to work around the well-known Shannon-Nyquist-Whittaker sampling theorem by exploiting certain properties in real world signals. This thesis will explore the theory behind compressive sensing and demonstrate its implementation toward laser ranging, cumulatively known as compressive laser ranging. Experiments were set up using electronic and photonic devices combining the theory behind compressive sensing and laser ranging and successful results measuring distances to multiple targets were obtained. The experimental setup was also implemented on an FPGA in an effort to create a compact laser ranging system.Item Determining snowpack accumulation at snow course sites in southwestern Montana using climatic station data and meteorological parameters--an assessment(Montana State University - Bozeman, College of Letters & Science, 1984) Tremper, W. Bruce