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Characterizing Aerodynamic and Flutter Behavior of Flags in a Free Jet Flow
No full textFluid-Structure-Interaction (FSI) is a widely studied research area in the field of fluid dynamics since a detailed understanding of FSI flow behavior can impact a wide range of engineering applications like new generation parachutes used in space exploration, helicopter aerodynamics, bio-propulsion, and flexible wing aerodynamics. However, developing a detailed understanding of the underlying physics in an FSI flow can be challenging due to the non-linear nature of the coupling between fluid flow and structures. Therefore, this investigation aims to quantify the FSI behavior of a flag in uniform jet flow, specifically the aerodynamic performance, flutter movement, and fluid flow velocity around the flag. For this purpose, three flag samples of varying lengths were used, and experiments were performed for a range of three critical non-dimensional parameters, i.e., Mass Ratio (R1), Dimensionless Rigidity (R2), and Reynolds number (Re). The R1 and R2 values were varied from 1.48 to 2.77, and 1.3 x 10-3 to 14.4 x 10-3, respectively, and Reynolds Number was varied from 44 x 103 to 123 x 103. All experiments were conducted in the sub-sonic open jet facility at the University of Idaho's Experimental Fluids and Aerodynamics Laboratory. The aerodynamic load experienced by the flag was measured using a high-precision load cell. The flag movement was captured using a triggered image acquisition system, and Particle Image Velocimetry (PIV) was used to measure the velocity fields around the fluttering flag. The results showed that the longest flag model has a unique aerodynamic load characteristic, i.e., a drag crisis region for R2 from 3.1 x 10-3 to 5.3 x 10-3 followed by a drag recovery region for R2 from 1.9 x 10-3 to 3.1 x 10-3. All the studied flag models start oscillating with increasing Re and exhibit mode-2 oscillation behavior. With the further increase in Re, the longest flag model transitions from mode-2 to a mode-3 oscillation. Furthermore, these results suggest that the flag movement and oscillation modes contribute to observed drag by these models. Finally, the stability plots identify a new region highlighting the transition from mode-2 to mode-3 oscillation behavior.masters, M.S., Mechanical Engineering -- University of Idaho - College of Graduate Studies, 2021-0
The Relationship Between Postpartum Ovulation and Concentration of Nutritional and Inflammatory Blood Markers in Multiparous Dairy Cows
No full textPrevious research has shown the association between negative energy balance, changes in blood metabolites, and reproductive performance. Cows that ovulate later in the early postpartum period exhibit an increased time to pregnancy. Thus, delayed ovarian cyclicity ultimately leads to longer calving intervals, multiple AI attempts, and loss of profit. Although relationships exist between inflammatory blood biomarkers and disease states, the relationships between these biomarkers, postpartum ovarian cyclicity, and fertility in dairy cows have not been thoroughly investigated. The objective of this study was to examine the relationship between body condition score (BCS), glucose (GLU), cholesterol (CHO), free cholesterol (FCHO), serum amyloid A (SAA), and resumption of ovarian activity during the early postpartum period in lactating dairy cows. Sixty-seven multiparous Holstein cows were monitored from 2 weeks prepartum to 8 weeks postpartum. Weekly blood samples, BCS, and ultrasonography were obtained to characterize inflammatory responses, energy status, ovarian structures, blood progesterone (P4), and the approximate timing of ovulation. Cows were divided into two groups; early ovulation (EO 28 DIM; n=46) and healthy (H; n=40), vs sick (S; n=27). As expected, BCS decreased over time for both groups (P masters, M.S., Animal and Veterinary Science -- University of Idaho - College of Graduate Studies, 2021-1
Developing a Pre-service Teachers’ Critical Literacy Beliefs Instrument
No full textThis study focuses on pre-service teachers’ experiences and beliefs about critical literacy, the importance of critical literacy, and the lack of explicit practices known about how to teach critical literacy in pre-service teacher education. Data were collected for eight weeks using the Critical Literacy Beliefs Survey (CLBS-1). A sample (N=405) of pre-service teachers from across the United States were recruited to take the Critical Literacy Beliefs Survey. The CLBS-1 was developed to examine pre-service teachers’ beliefs of critical literacy and answer the following research question: To what extent does the Critical Literacy Beliefs Survey (CLBS-1) represent the hypothesized dimensions of critical literacy found in the literature?Survey-development methods (Johnson & Morgan, 2016) were used to examine if Lewison et al.’s (2002) critical literacy framework can be rendered into a quantitative instrument to explore pre-service teachers’ critical literacy beliefs. Using Confirmatory Factor Analysis (CFA), the factor structure of the CLBS-1 was examined and compared to the collected data from a pre-service teacher sample. Findings from the CFA showed a three-factor structure. Model fit was satisfactory upon revision (CFI = .93, TLI = .91, RMSEA = .09, SRMR = .05). The current findings can be discussed only in the context of the sampled population, contingent upon the revision of the CLBS-1 through multiple iterations with a random population of pre-service teachers to deem this instrument a valid and reliable measure of their critical literacy beliefs. More surveying on and with this teacher population is needed to further explore how critical literacy can be examined in larger-scale studies.doctoral, Ph.D., Curriculum & Instruction -- University of Idaho - College of Graduate Studies, 2021-0
Off Ramp of the Pleistocene: A Review of the Taxonomy, Osteology, and Biogeographic Distribution of Late Pleistocene Mammoths of Idaho
No full textMammoths were endemic on the North American continent during the late Pleistocene to early Holocene and are considered a keystone species in paleoecology. Here, I examined the skeletal remains of a mammoth excavated from southeastern Idaho to provide insight into its depositional age, taxonomy, and ontogeny. This multidisciplinary analysis revealed possibly the first M. jeffersonii hybrid reported in Idaho that lived 11,700 +/- 40 years ago. The remains belonged to a male mammoth that was a juvenile between 18 and 28 years old. Its remains were preserved in an ancient hot spring deposit during a time within 500-1000 years of the final megafaunal extinction on the continental landmasses. This mammoth is one of the last mammoths in mainland North America before the species’ ultimate extinction.masters, M.S., Geology -- University of Idaho - College of Graduate Studies, 2021-0
Multivariate Patterns in Potential Environmental Covariates of Elk Abundance in Three Oregon Management Regions
No full textThe purpose of this study was to evaluate top-down and bottom-up effects controlling elk (Cervus elaphus) recruitment by making inferences concerning the predator-prey dynamics of elk and mountain lions (Puma concolor) inhabiting Northeast Oregon ecosystems. We formulated hypotheses about the environmental drivers of the number of elk observed in annual surveys, bulls per hundred cows, and calves per hundred cows in annual surveys of three elk populations in Northeast Oregon. The study analyzed key environmental factors gathered from 1962-2007 which potentially control the elk population growth rate in three management units: the Snake, Wenaha, and Desolation areas. The study was conducted using principal component analysis, canonical correlation analysis, and multiple regression analysis to determine covariates to characterize potential top-down and bottom-up effects which defined elk abundance and recruitment in all three management units. Overall, in Wenaha area, 70% of variation in elk recruitment as measured by calf to cow ratios was induced by the cougar abundance and total elk harvest. In the Snake and Desolation areas respectively, 54% and 40% of the variation in elk abundance was explained by the cougar abundance and harsh weather climate. The correlation patterns in the Snake unit was consistent with additive mortality from predation while the patterns in the Wenaha unit was consistent with compensatory mortality from predation. The Desolation unit was consistent with both the additive and compensatory mortality from predation. Elk biologists and managers could conduct field research from these findings to test methods of preventing elk populations from declining in Northeast Oregon. Key words: top-down, bottom-up, Cervus elaphus, Puma Concolor, Northeast Oregon, population abundancemasters, M.S., Environmental Science -- University of Idaho - College of Graduate Studies, 2021-0
Dissolution Phenomena of Nuclear Research Reactor Fuel Constituents in Molten Salt Systems
No full textIn its 70-year history, Idaho National Laboratory has pioneered significant nuclear advancements and enduring technologies, including liquid metal reactors with an accompanying electrometallurgical treatment process for conditioning the reactor’s used metallic fuels, pressurized water reactors operating with uranium oxide fuels, and materials testing reactors operating with aluminum matrix fuels. These highly productive nuclear technology developments at the Laboratory have resulted in a legacy of nuclear fuels and materials that require stabilization prior to their ultimate disposal. A primary concern with disposal of these materials is their potential release of radioactive constituents into the biosphere. One way to lessen the burden on a repository for used nuclear fuel and materials is to process them into waste forms that are more robust than the used fuel matrix itself. Such is an outcome of the electrometallurgical treatment process, which is based on molten salt dissolution of specific metallic fuels and could be extended to other used nuclear fuels. The aim of this study was to examine molten salt dissolution techniques that could be used to address stabilization and disposition of select legacy nuclear fuels and materials at the Laboratory. Specifically, the scope of this study was limited to dissolution phenomena of nuclear research reactor fuel constituents in molten salt systems. Fuels and constituents in this study included (1) used nuclear oxide fuels, (2) aluminum matrix fuels, (3) bond sodium from metallic fuels, and (4) uranium metal and hydride to synthesize high-purity uranium trichloride for use in molten salt dissolution studies. The dissolution of used nuclear oxide fuels in molten salt systems initially involved contacting various forms of nuclear oxide fuel in molten lithium chloride – potassium chloride eutectic with 9 wt% uranium as the trichloride at 500°C. Alkali, alkaline earth, lanthanide, and transuranium constituents partitioned from the oxide fuels into the molten salt phase to varying extents with a wide range of 12 – 99%. Higher extents of fuel constituent dissolution were attributed to reducing conditions in the fuel matrix and preconditioning of the fuel. Subsequent experiments were performed in which reducing conditions in preconditioned oxide fuel were created via electrolytic and chemical-seeded means. Other parameters, including higher operating temperatures (500 to 800°C) and uranium trichloride concentrations (upwards of 19 wt% uranium as the trichloride), were investigated in these experiments, leading to fuel constituent dissolution above 90%. Dissolution of an aluminum fuel matrix involved contacting and heating neodymium metal (as a surrogate for uranium metal) and aluminum metal (in foil and particulate form) initially with lithium and ammonium chloride. The aluminum metal forms reacted into volatile aluminum chloride, separating from the neodymium metal which simultaneously reacted to form neodymium chloride and fused with the lithium chloride. Experiments were repeated with lithium and ammonium bromide to assess the performance of a bromide system vis-à-vis a chloride system. Extents of aluminum removal ranged from 94.5 – 98.2% and 91.4 – 97.8% for the chloride and bromide systems, respectively. Sodium metal was deactivated into molten salt systems via reaction with non-metal (ammonium) and metal (ferrous) chlorides. The reaction of molten sodium metal with metered ammonium chloride particulate proceeded without excursions, producing a pure colorless sodium chloride. The reaction of molten sodium with ferrous chloride yielded occasional excursions and salt fuming, producing a dark salt-metal mixture. These experiments identified a controlled technique to convert reactive and pyrophoric sodium metal into a stable sodium chloride – a technique that could be applied in a remote-handled inert-atmosphere environment with sodium metal containing elevated levels of reactivity, such as bond sodium in used nuclear metallic fuels. Uranium metal and uranium hydride were separately reacted with ammonium chloride in the presence of lithium chloride – potassium chloride eutectic to form a ternary mixture of uranium trichloride with the alkali-metal chlorides. Similar experiments were performed to synthesize a eutectic mixture of sodium chloride – uranium trichloride. Extensive characterization of the synthesized products was performed to assess their form and purity. This collection of experimental studies highlights the safety and effectiveness of molten salts at dissolving select used nuclear research reactor fuel constituents under specific conditions. When applied to used fuels, the radioactive components in the molten salt systems may be further treated, as needed, into leach-resistant, robust waste forms for ultimate disposal in a federal repository.doctoral, Ph.D., Chemical and Materials Science Engineering -- University of Idaho - College of Graduate Studies, 2021-0
Understanding the Liminal Space between Science and Archaeology: pXRF in Historical Archaeology
No full textThere exists a shared space where archaeologists use techniques developed by scientists to explore archaeological questions. Portable x-ray fluorescence spectrometry (pXRF) is one such technique where archaeologists are uncovering appropriate archaeological applications. However, pXRF is currently used mainly by prehistoric archaeologists examining obsidian artifacts and is only used sparingly by historical archaeologists. This thesis sets out to explore the liminal space between science and archaeology through a case study of the use (or lack thereof) of pXRF in historical archaeological contexts. This mixed-methods qualitative study has three parts: (1) an examination of the history of the relationship between archaeology and science, (2) semi-structured interviews with eight historical archaeologists and two representatives of manufacturers experiences with pXRF, and (3) a scoping literature review of published historical archaeological research in the last two decades. Data suggest that historical archaeologists are negotiating inclusion of their work into the boundary of ‘science’; meaningful, varied, and successful research is currently being conducted, but there are negative feedback loops that prevent wider usage. Although participants spoke with enthusiasm about their own work and future applications of pXRF in historical archaeology, they described barriers with training, lack of published methodologies, and a generally negative climate surrounding historical archaeological applications of pXRF, which is reflected in the lack of peer-reviewed published literature discovered in the scoping review. However, this study suggests that pXRF is useful tool, with limitations, that, with further research, has the ability to be applied appropriately in more historical contexts to answer interesting and novel archaeological questions. However, determining ‘appropriateness’ of various applications depends entirely on (re)negotation of the boundaries between archaeology and science, which is mediated by the complicated historic relationship between the fields.masters, M.A., Anthropology -- University of Idaho - College of Graduate Studies, 2021-0
OPPORTUNITES FOR ADDING VALUE AND INCREASING CONSISTENCY OF BEEF
No full textOversized beef carcass and tenderness are issues the beef industry is working to overcome. The objectives of this research were to: 1) assess the effects of beef carcass size and its relationship to chill time, color, pH, and tenderness of the beef top round, 2) assess three aging periods of commercially available top rounds from varying carcass weights as it relates to retail shelf-life and color stability, 3) survey environmental parameters of commercial dry-aging facilities from selected regions of the United States, and 4) determine the effect of dry-aging parameter influences on eating quality of dry-aged beef. Eight industry average weight beef carcasses and eight oversized beef carcasses were evaluated for temperature and pH measurements for the initial 48 h postharvest. The top round anatomically deep location cooled at the slowest rates and had more rapid pH declines. Additionally, the deep portion of top round steaks from oversized carcasses was the lightest and most yellow in color. Furthermore, the drastic color difference between the superficial portion and deep portion of the top round steak is further amplified as carcass weights increase. Retail characteristics varied with aging times, and differences were further amplified by carcass size. Alternative top round steak fabrication which separates the deep and superficial anatomical locations could be an effective means of providing consumers with more uniform steaks at the retail counter. Commercial dry-aging facility cooler conditions varied in cooler temperature, percent relative humidity, and wind speed. Consumer taste panel results identified differences in dry-aged steak acceptability, tenderness, and flavor based on location. The findings indicate that conditions within individual dry-aging facilities aid in producing unique dry-aged beef flavors. Overall, the results of these studies indicate opportunities for adding value and increasing consistency of beef.doctoral, Ph.D., Animal and Veterinary Science -- University of Idaho - College of Graduate Studies, 2021-0