University of Idaho Library Digital Initiatives
Not a member yet
54971 research outputs found
Sort by
Deep Creek bridge at Highway 95
No full textPhotograph of the Deep Creek bridge prior to replacement at Highway 95
Life in Potlatch Was Different & Farewell to the Potlatch Mill
No full textLife in Potlatch Was Different, by R.K. Harris and Farewell to the Potlatch Mill, by Keith Peterse
CHARACTERIZATION OF UNCERTAINTIES IN THE MODELING OF ABLATION HEAT TRANSFER IN ROCKET NOZZLES
No full textAblation of carbon cloth phenolic insulators used in solid rocket motor (SRM) nozzles involves highly complex phenomena that is difficult to accurately predict. Historical and even more modern ablation predictions rely heavily on anchoring to SRM testing data to improve predictability and SRM reliability. Accelerated schedules, reductions in static SRM testing prior to flight, and a highly competitive global market are placing substantial onus on computational capability. Strong shifts from real-world testing to advanced modeling capabilities are placing emphasis on ablation modeling uncertainty. Without funding or schedule for multiple test firings it is essential to cover the proper amount of uncertainty in nozzle designs. The importance is further exacerbated by modern views of low realized risk in SRM designs. This study aims to ease these challenges by quantifying uncertainty in ablation predictions of carbon cloth phenolic insulators exposed to SRM nozzle environments. A particular historical test motor is used as a demonstration case. System response quantities of interest are erosion depth and char depth. Model and input uncertainty are quantified and characterized using a comprehensive approach. Sensitivity analysis on inputs relevant to ablation system response quantities of interest is performed to identify influential parameters. Due to the inherent extent of numerical simulations required, surrogate modeling techniques are assessed and applied based on computational efficiency and accuracy. Uncertainty in numerical models and inputs are propagated through a two-dimensional uncertainty quantification using a Latin Hyper Cube sampling methodology. Results of this study show that the primary sources of uncertainty in SRM thermal modeling are incident radiation heat flux, heat transfer coefficient, char material thermal conductivity, virgin material density, char material density, char material specific heat, and pyrolysis gas enthalpy. Uncertainty in the predictions of nozzle insulation erosion and char for the test case are provided relative to nozzle location at the 99th percentile and 95th confidence interval. Following the uncertainty quantification, approaches to reducing uncertainty and recommended future work are provided.doctoral, Ph.D., Mechanical Engineering -- University of Idaho - College of Graduate Studies, 2022-1
Investigating the Chemistry and Biomechanical Strength of Stalks for Understanding Lodging
No full textSorghum is an important crop mainly grown for food, animal feed, bioenergy, and fiber requirements. The production of a higher yield is compromised by its stalk lodging. Stalk lodging, the permanent displacement and mechanical failure of stems from their natural position prior to harvesting, poses a serious agronomic challenge leading to substantial yield losses annually. Despite its enormous economic impact on commercial crops, stalk lodging mechanisms are not clearly understood. Previous studies used methods such as bending tests, histochemical methods, rind penetrometer, and crushing strength measurements to understand stem biomechanical behavior. However, these approaches are inadequate to fully understand the lodging, as the structural composition of the stalks was not considered. Thus, approaches involving compositional analysis together with the biomechanical behavior of the crops will improve our understanding to develop lodging-resistant varieties and narrow the knowledge gap in stalk lodging mechanisms. This study evaluated stem biomechanical, compositional, and microstructural traits to assess their relationship with mechanical strength and/or loading. The whole biomass composition of Della (D) and its mutant REDforGREEN (RG) sweet sorghum stalks grown in 2018 (D1, RG1) and 2019 (D2, RG2) were examined employing different analytical instruments. Noticeable changes in the composition of fatty acids, structural carbohydrates (glucan, and xylan), and lignin content and structure were found, attributable to growing season and mutation factors. The results revealed that D2 had the highest lignin content, while RG1 had the lowest lignin content. Particularly in RG1, Klason lignin reduction by 16-44 % at the internode was detected. Lignin from the sorghum stalks were enriched in guaiacyl units and syringyl/guaiacyl ratio was increased in RG1 and RG2 respectively by 96% and more than two-fold at IN. In addition, the chemical composition, biomechanical properties of rinds, and the microfibril angle (MFA) of the S2 cell wall were determined. The flexural modulus (FM) and flexural strength (FS) showed a significant reduction for RG. Particularly, a reduction of FS by (16-37%) and FM (22-41%) were detected for RG1. Changes in the stalk rind biomechanical properties were found positively correlated with total lignin and glucan/cellulose contents, and inversely proportional to MFA. However, the contents of xylan/hemicellulose in the rinds were not significant for the strength. The result suggested that the lodging resistance of sorghum stalk would be improved by increasing the amount of cellulose and lignin. The results can also provide biotechnological targets in breeding programs aimed at improving lodging resistance in sorghum.doctoral, Ph.D., Environmental Science -- University of Idaho - College of Graduate Studies, 2022-1
Navigating New Waters: A Case Study of Settler Colonialism in the Coeur d’Alene Tribe’s Legal Fight to Protect its Homeland
No full textThe western legal system has historically forced tribes to fight for their sovereignty in legal frameworks that can be antithetical and outright hostile to their value systems, in a court system that relies on conceptions of tribal land and property rights that are steeped in 15th century notions of racial inferiority. This study examines how one tribe, the Coeur d’Alene Tribe in northern Idaho, pursued legal affirmation of its ownership of Coeur d’Alene Lake and its tributaries in multiple courts over a period of thirty years so that it could improve its standing in separate but concurrent suits against mining corporations that had polluted the Tribe’s waters. The overarching research question guiding this study was: How has settler-colonialism impacted the Coeur d’Alene Tribe in its battles to assert sovereignty over its land and water? An in-depth instrumental case study of the Tribe’s legal history related to Coeur d’Alene Lake was conducted using the Tribe’s extensive legal archives. Additionally, a document analysis was combined with thematic analysis to consider one of the Tribe’s multiple cases: Idaho v. U.S., 533 U.S. 262 (2001), a case that involved the United States as lead plaintiff with the Tribe as intervenor-plaintiff suing the State of Idaho to quiet title for the United States on the southern third of the lake with the Tribe as beneficiary. The major understandings from this study were 1) Doctrine of Discovery and the legal conceptions of plenary power and domestic dependent nationhood that derive from the doctrine constrain full recognition of the Tribe’s historic and contemporary relationship and ability to govern the lake, and 2) Federal Indian law is embedded in notions of White supremacy and racial inferiority that persists through both explicit concepts and the repetition of legal precedents that mask racist language that would be unacceptable in any other governmental setting. This research may inform future tribal efforts in environmental and legal battles. doctoral, Ph.D., Curriculum & Instruction -- University of Idaho - College of Graduate Studies, 2022-0
Gravitational Interactions and Resonances in Ring-Moon Systems
No full textWhile resonances determine the large-scale dynamical structure of planetary systems, interactions among the small bodies in these resonances impact their orbital evolution. We use numerical simulations to study the orbital evolution of interacting small bodies orbiting within two different locations in Saturn's rings, and of interacting equal-mass co-orbitals. Modeling the clumps in Saturn's D68 ringlet as co-orbital point-masses reveals the fragility of low-mass co-orbital satellite systems. Simulations of multiple massive bodies in a common corotation resonance site, such as the ring arc of Saturn's moon Aegaeon, reveal the importance of interaction timescales for multi-body orbital dynamics. We also investigate the planetary normal mode spectra of Uranus and Neptune to predict where in their rings we might expect to see resonant phenomena.doctoral, Ph.D., Physics -- University of Idaho - College of Graduate Studies, 2022-0
A Case Study Using Deep Learning to Identify North American Arthropods in Photographs
No full textIdentification of arthropods is important in academic and medical applications such as species-species interaction studies and identification for medical diagnosis. Deep learning is a tool that can be used to solve these problems quickly and accurately. For this study, a deep learning model was developed that has the capability of identifying North American arthropods to the genus level and compared multiple methods to increase the performance of this model. These methods include changing the neural network architecture, class balancing, and changing the image input size. The full deep learning model using InceptionResNetV2 obtained top 1 accuracies of 80% and top 5 accuracies of 92%. Comparatively, it was found that changing the neural network to EfficientNetB7 in a subset of the full model achieved a top 1 accuracy of 90%. It was also found class balancing in certain circumstances increased recall and that increasing image input size had a logarithmic effect on performance.masters, M.S., Bioinformatics & Computational Biology -- University of Idaho - College of Graduate Studies, 2022-0
Unlocking keystone structures: Opening the door to new uses of airborne and handheld lidar for remote characterization of standing dead trees and nest cavities in closed-canopy conifer forests
No full textIn closed-canopy conifer forests, standing dead trees (known as snags) serve as keystone structures, supporting disproportionate amounts of biodiversity. Their reduced woody structure, as well as their decaying wood, make snags different enough from live trees to provide unique habitat features for wildlife. One such feature of snags in northwestern conifer forests¬ is that they are the preferred sites for woodpeckers to excavate nest cavities, which are also considered keystone structures in this system. Woodpecker cavities are essential to multiple species of birds and mammals for nesting and roosting–and this habitat feature makes locating snags all the more valuable. Using remote sensing to map where snags occur across the landscape is of great benefit in multiple ecological contexts but is made difficult due the sparse, cryptic, and variable nature of standing deadwood throughout a forest.This dissertation tests novel methodologies to evaluate whether one type of remote sensing, light detection and ranging (known as lidar), applied at different spatial scales is sensitive enough to discern structural characteristics pertaining to: (1) snags versus live trees; (2) variation among snags; and (3) tree cavity entrance dimensions. I evaluated lidar at the landscape scale for (1) and (2) to explore the capabilities of airborne lidar for snag detection and characterization in conifer stands of the Idaho Panhandle National Forest. I evaluated lidar at the individual tree scale for (3) to determine the accuracy of smartphone lidar in measuring cavity entrance dimensions under controlled conditions. I found airborne lidar to be (1) effective at distinguishing between snags and live trees at the individual tree level using the proportion of open space surrounding each, but (2) airborne lidar was not high enough resolution to reliably characterize multiple snag classes. I found that smartphone lidar (3) was very accurate in measuring at least one dimension of cavity entrance size, enabling discernment among species of cavity excavators.doctoral, Ph.D., Natural Resources -- University of Idaho - College of Graduate Studies, 2022-0
Modeling Natural Convection Through RELAP5-3D
No full textModeling a system with natural convection being the coolants primary driving force is fre-quently challenging due to the programs governing equations not accounting for pressure difference in calculating the mass flow rate. The objective of this project is to create a pro- gram that can run a model with the only driving force being the natural convection formed from the pressure difference between an energy sink and an energy source. To accomplish this the software RELAP5-3D will be used in the one-dimensional format. The model will not have any pumps within the program to ensure the evaluation is capturing only the mass flow rate from the natural convection forces. The only fluid that will be contained within the system is H2O in both gas and liquid form. The model is divided into four separate executable programs due to complication of the mass flow rate oscillating during initial startup of the program. The results showed that the RELAP program can run a system using the pressure differences as the driving force for the mass flow rate of the coolant fluid. The result had uncharacteristic oscillations in both the mass flow rate and temperature of the coolant. This is most likely due to the one-dimensional format of the model. It is recommended to modify to a two-dimensional model to reduce the oscillations within the system. When comparing to hand calculations there is a considerable difference between the two values. Without the physical models mass flow rate data to compare, the results are inconclusive as to the accuracy of both evaluations data.masters, M.S., Mechanical Engineering -- University of Idaho - College of Graduate Studies, 2022-1