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Finite Element Analysis Validation in Ball Bearing and Linkage Assemblies for Exoskeleton Robotics
No full textStroke is one of the leading causes of disability in the world today. Many individuals who have suffered a stroke experience upper-extremity impairment, reducing their quality of life. Studies have suggested that with proper rehabilitation and assessment these individuals can achieve greater recovery, thus improving the lives of many. BLUE SABINO, an exoskeleton being developed at the University of Idaho, is being designed to help assess these stroke patients as well as assist in the rehabilitation process. One of the greatest challenges while designing an exoskeleton is keeping it lightweight while simultaneously ensuring adequate rigidity. Finite element analysis (FEA) is an engineering tool that allows computer models, of structural assemblies/components, to be simulated under specified loading conditions. For structural applications these simulations result in estimates of stresses, strains, and deflections. This tool allows engineers to assess a variety of scenarios rapidly without manufacturing physical components, saving money and time during the design process. However, careful implementation is required to achieve accurate results. This thesis describes three experiments that are compared to their FEA counterparts to check the validity of the solution. One of the assemblies acted as a control test, only featuring bolt connections. The other two assemblies consisted of similar bolt connections while also including multiple bearing connections. The control test was used to find an optimal mesh that kept simulation times low without compromising accuracy and resulted. Comparing the simulation to the experimental data resulted in an error 6.6%. While performing the simulations for the bearing tests, axial and lateral stiffness values could be assigned to the bearings. An optimal value of 3.5e7 N/m (lateral stiffness) and 3.75e5 N/m (axial stiffness) was determined, resulting in solutions with errors of -1.04% and -0.28% at a load of 200N. Using these optimized stiffness values while varying the simulation’s applied load resulted in increased error for both models, with a maximum error of 24.6%. These results show that FEA can be used to accurately predict deflections in bolted and bearing connections used in exoskeletons and provided insight that the bearings were the main source of deflection within the assembly.masters, M.S., Mechanical Engineering -- University of Idaho - College of Graduate Studies, 2019-1
Myogenic Transcription Factors and Ornithine decarboxylase mRNA are Influenced by Polyamine Supplementation in vitro.
No full textPolyamines; putrescine and spermine are important nutrients that support cell proliferation, and growth. Study of the influence of polyamines in skeletal muscle growth is limited. This research is driven towards understanding nutritional means for optimizing muscle growth in cattle. Using commercial cell lines; c2c12 and sol8 cells the effects of physiological doses of polyamines in undifferentiated and differentiated cells was assessed in the context of mRNA analyses of key myogenic transcription factors and the mRNA for the rate limiting step for de novo synthesis of polyamines; ornithine decarboxylase. Myogenic transcription factors (MyoD, Myf5, myogenin) and ODC mRNA were measured at 8 and 16 hr. time points after treatment with polyamines, or methionine (aa control) or no polyamine supplementation (control). Exogenous supplementation with putrescine (5mM) or spermine (0.5mM) in undifferentiated c2c12 and sol8 cells significantly increases in myogenic transcription factors and ODC mRNA. However, polyamine treatment of differentiated c2c12 and sol8 cells resulted in a significant decrease in myogenic transcription factors and ODC mRNA at similar time points. Methionine (10mM) treatment of undifferentiated c2c12 and sol8 cells did not show a significant difference in their myogenic transcription factor mRNA relative to control, however ODC mRNA increases. Treatment of differentiated c2c12 and sol8 cells with the amino acid control; methionine (10mM), resulted in a similar pattern of mRNA abundance as was observed for polyamine treated differentiated cells. These results indicate that polyamines may induce a promyogenic state in undifferentiated myoblasts (c2c12 and sol8) at 8hr and 16hr as compared to controls, though the evaluation of more time points as well as further study in differentiated myoblasts is critical for a clearer understanding of the role of polyamines in skeletal muscle growth.masters, M.S., Animal and Veterinary Science -- University of Idaho - College of Graduate Studies, 2019-0
Forest Ecosystem and Avian Niche Modeling: Improving Climate Change Forest Modeling via Interdisciplinary Model Linking
No full textClimate change is impacting forest structure and processes, and more than half of the forested land cover of North America will experience future climates that differ from historical growing conditions. Forest composition and structure are integral to biodiversity, however, climate change induced declines in tree species occurrence, increases in forest mortality events, and increases in burned area will have biodiversity implications. Process-based forest landscape models provide a means to evaluate forest structure, composition, and biogeochemical responses to climate change, while providing data to secondarily model biodiversity responses. This dissertation focuses on integrating forest landscape and avian niche models to evaluate the effects of climate change on the Northern Rockies Ecoregion of Idaho, USA. Chapter 1 addresses the rational for integrating avian cavity nester niche models with forest landscape models. I introduce the conceptual climate-woodpecker-forest model and conduct a literature review of ongoing and projected responses of woodpeckers to climate change. I found that projections are not always in agreement with observed contemporary trends, and the ecological constraints associated with contemporary woodpecker niches are not being integrated into climate-based projection models. I conclude that the coupling of woodpecker niche models with finer scale process-based vegetation models is a way to better approximate the key ecological constraints of woodpeckers. This coupling will then provide a functional measure of biodiversity in multi-objective ecosystem modeling frameworks. In Chapter 2, I propose a framework to integrate avifauna niche and forest landscape models. The framework implements a process to 1) aid in selecting available and appropriate niche models for a study region; 2) evaluate the transferability of a niche model when developed in a region outside of the focal study area; 3) derive niche model predictor variable parameterizations from the forest landscape model when the outputs of the forest landscape model cannot directly inform the avian niche model; 4) compare the forest landscape modeled avian niche response to the response derived from the original niche model parameterizations. Through implementation of this process using two avian cavity nester species and the forest landscape model LANDIS-II, I found model selection and transferability are the primary limiting factors to integration. Secondarily, species that are spatially irruptive because of the dynamics of habitat condition still benefit from this model integration. The spatial extent of core habitat features of these species, which are a product of long term management decisions, can be identified and further evaluated through time using forest landscape model scenarios. Overall, the framework provides a viable process to model integration. In Chapter 3, I apply LANDIS-II to the Northern Rockies Ecoregion to evaluate the effects of climate change, fire disturbance, and harvest disturbance on the forest composition, structure, and biogeochemical dynamics of the region. I integrate the avifauna niche models from Chapter 2 into the modeling scenarios to provide a measure of biodiversity response. The Northern Rockies Ecoregion is projected to …doctoral, Ph.D., Environmental Science -- University of Idaho - College of Graduate Studies, 2019-0
Imagine that You Close Your Eyes
No full textI seek to create visual fields that hold space for viewers, whether they be imagined or physical images, that through the act of viewing, can internalize an experience similar to that of my own creation process. In my creative research, I don’t seek to define what my artwork will depict when I begin, but rather I seek to be present through it. How I define space is often gestural and suggestive of an expanse that exists outside of our everyday understanding. It is the thing of which there are no words to describe. Consider this suggestion: imagine that you close your eyes. This phrase distills the essence of creation by way of limiting it to the cognitive form. By asking the viewer to confront the contradictory act of attempting something that is seemingly impossible, I am leaving them suspended in a space that is full of potential. The same can be said for asking someone to hug the air. There is something to be considered in the vacant space created in the shell of their body and arms. It is up to the individual to imagine who or what could occupy that space. My work is an open invitation for the audience to consider the roles of form, memory and introspection and how we as creative beings can use them to reconcile that which we know to exist but are unable to define.masters, M.F.A., Art & Design -- University of Idaho - College of Graduate Studies, 2019-0
An Experimental Approach to Determine Skill Level at Obsidian Biface Cache Site 35MA375, Salem, Oregon
No full textA landowner in Salem, Oregon, recovered an obsidian biface cache during the excavation of a spring fed pond in 2015. This unique archaeological site (35MA375) is the only recorded obsidian biface cache within Oregon’s Willamette Valley. The cache provided a unique opportunity to examine bifacial blanks and produce data useful for interpreting other biface caches in the region. These obsidian bifacial blanks had natural and anthropogenic attributes that may hinder further reduction. Assessing a flintknapper’s skill level may give us insight into why the bifaces have characteristics and attributes undesirable to an experienced flintknapper. I worked with novice, intermediate, and expert flintknappers to produce 15 obsidian bifacial blanks each. The project goal is to determine if skill level can be designated by comparing the technological analysis of the original bifacial blanks to those produced by flintknappers who vary in skill level. This approach provides information about choices and strategies used by novice flintknappers as they become progressively familiar with stone tool production.masters, M.A., Anthropology -- University of Idaho - College of Graduate Studies, 2019-0
She Can’t Always Get What She Wants: Aspirations Versus Actualities Where Work and Motherhood Converge
No full textUsing original survey data from a convenience sample of 1,776 mothers across the United States, this research explored the intersection of motherhood and women’s paid work at three distinct axes: 1) before the arrival of children, as women make plans about how and whether to alter their paid work to accommodate the demands of childrearing, 2) immediately following the transition to motherhood, as they attempt to translate their initial plans into on-the-ground arrangements, and 3) over the ensuing years of raising children. Mixed methods analysis identified that mothers’ preferences, resources, and logistics influenced mothers’ initial decision-making as well as the work paths they subsequently followed. The quantitative data allowed for the tracking of large-scale patterns, while the complementary open-ended responses revealed more nuanced sources of support and constraint that bolstered or impeded mothers in attaining (and maintaining) arrangements that suited their unique circumstances. By giving voice to the mothers on the ground, both those who are valiantly making it all work and those who feel frustratingly stuck in less-than-ideal arrangements, this research paints a more complex and honest picture of the pushes and pulls where work and motherhood converge.masters, M.S., Family and Consumer Sciences -- University of Idaho - College of Graduate Studies, 2019-0
A Journey of Self-Love
No full textA Journey of Self-Love is a visual narrative in the form of ten water-colored relief prints that, explore my personal journey towards the reunion with my authentic self. This colorful collection of prints investigates themes of self-discovery: my connection to nature, energy healing and experiences, metaphysics, and the rising of the holy oil.masters, M.F.A., Art & Design -- University of Idaho - College of Graduate Studies, 2019-0
Characteristics of High-Quality Career and Technical Education Teachers
No full textThis study was designed to explore high-quality teacher characteristics of Career and Technical Education (CTE) teachers. It is generally acknowledged that promoting teacher quality is a key element in improving secondary education in the United States. While recent research has documented the importance of quality teaching in promoting student achievement, there is a lack of consensus on the characteristics of good teachers because identification of good teaching practices are often dependent on student learning outcomes. The purpose of the study was to explore and inventory the characteristics of Idaho’s high-quality CTE teachers (i.e. knowledge and skills, beliefs, and practice) without using student learning outcomes as a measure. The survey was distributed to 770 postsecondary teachers in the State of Idaho with a response rate of 44.8%. Significant results from the study indicated Idaho’s CTE teachers have strong self-efficacy, a growth mindset, and believe that having a mentor was related to their success as a teacher. The inventory of teacher characteristics formed the CTE-CTI Framework: Characteristics of a high-quality CTE teacher which depicted education and experience, professional development, beliefs, great teacher attitudes, and related practice components. This study is considered to be generalizable. With noted revisions, the CTE-CTI can be used to inventory the characteristics of high-quality CTE teachers.doctoral, Ph.D., Curriculum & Instruction -- University of Idaho - College of Graduate Studies, 2019-0