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Evaluation and Improvements to a Mechanical Engineering Capstone Designed Autoclave System for Use in High Temperature Aqueous Environments
No full textServohydraulic load frames have been used to perform fatigue testing for decades. Additions to these frames, such as high temperature furnaces and torsional stressing, have allowed for increased research opportunities. An area of additional needed fatigue research is the nuclear industry. Crack growth analysis in an aqueous reactor environment with high temperature and pressure is needed. Specimens in this environment provide fatigue data in a corrosive environment when subjected to these conditions for long tests. To gather this data, a new experimental system is required. One such system was designed by a senior capstone group at the University of Idaho. The system was developed from a modified autoclave with a servo-hydraulic frame attached to it. The system was designed to be attached to a fluid control panel that would circulate pressurized water into the autoclave. This system could be heated and would fully simulate a reactor environment. Several issues emerged in the building of this system. The control and functionality was limited, causing the need for future improvements. Improving the cooling jacket, seals, fluid control, and data collection process was performed. Several iterations of these processes were attempted. Preliminary testing of these new devices was performed to show the progress and results. Data was collected in both air and water as the working fluid filling the autoclave chamber. Several heated and pressurized tests were performed as well. Problems were encountered upon several stages of the initial testing. While promising results were gathered, future improvements are still needed. Safety features as well as additional system cooling will need to be applied. Once completed, this system can perform fatigue testing in a heated and pressurized aqueous environment simulating that of a reactor.masters, M.S., Mechanical Engineering -- University of Idaho - College of Graduate Studies, 2020-0
Community and Reciprocity in Conservation Aquaculture of Pacific Lamprey and Western Freshwater Mussels: Species of Importance to Native American Tribes of the Columbia River Basin
No full textColumbia River Plateau tribes, such as the Confederated Tribes of the Umatilla Indian Reservation (CTUIR), have developed sustainable relationships with communities of food resources throughout the Pacific Northwest (PNW) since time immemorial (i.e., as far back as time is recalled or recognized). These relationships are evident in tribal creation stories, where plants and animals offered themselves to sustain humans, and in turn humans were given the responsibility of reciprocity—to take care of the foods that take care of them. Today, indigenous organizations like the CTUIR fulfill the promise of reciprocity by developing research programs that are focused on restoring ecological and cultural services. For many indigenous groups, traditional ecological knowledge (TEK) drives these programs and restoration objectives. Policies and management frameworks that are based on TEK promote the restoration of both physical and biological river processes that include important interspecies linkages and community interactions (Chapter 2). Interactions between First Foods, traditional foods of cultural importance (e.g., water, fish, big game, roots, and berries), and their environments are critical to tribal natural resource management. The populations of two First Foods, Pacific Lamprey Entosphenus tridentatus and native western freshwater mussels, are declining in the Columbia River Basin in the western United States. Specific reasons for these declines are not well understood but are linked to changes to the biotic and abiotic features of the system. Physical habitat alterations, declining water quality and quantity, and changes to the biotic community structure of the river are possible factors that are affecting population declines of lamprey, mussels, and other native aquatic species (e.g., salmon, trout, and nongame native fishes). The loss of cultural connection to Pacific Lamprey and native freshwater mussels and the loss of the ecological services that are provided by these organisms are understudied elements of most Pacific Northwest aquatic-restoration projects. The positive contributions of lamprey and mussels to the river environment have been explored through limited studies. For example, larval lamprey can affect the benthic microbial community structure, promoting more aerobic than anaerobic microbial species. They also contribute to nutrient cycling, processing organic matter and waste products from other river organisms. Freshwater mussels provide numerous ecosystem services to the river community, including water filtration, nutrient cycling and storage, and food-web connections. For example, macroinvertebrate communities associated with mussel beds are larger and more diverse than those not associated with mussel beds; these macroinvertebrate communities in turn provide food and ecosystem services for other river organisms. Mussels are reliant on fishes to provide nutrients and transportation to their larvae, which transform into juveniles while on the fishes. Reciprocity drives community interactions and flows from the benthos to higher and lower trophic levels. The community interactions that are observed in the river environment can be further investigated through laboratory study to improve culture techniques for both lamprey and mussels. Lamprey and mussels require artificial propagation and laboratory culture to supply organisms for research and restoration. Providing community interactions during laboratory rearing can benefit cultured organisms. In this dissertation, I use macro- (teleost fishes) and micro- (bacteria) organisms to study community interactions in the context of artificial propagation and rearing of freshwater mussels (Chapter 3) and Pacific Lamprey (Chapters 4 and 5). A healthy, thriving community in any freshwater system requires that all parts of the system are functional and connected, a sentiment popularized for a western audience by Aldo Leopold’s Land Ethic essay in the 1940s. Aquatic restoration projects that are implemented to improve habitat for salmonids can also serve to improve habitat for benthic organisms like larval Pacific Lamprey and native freshwater mussels with little extra effort or expense. To restore populations to harvestable abundances, inclusion of lamprey and mussels in ongoing habitat restoration projects should be a priority for Columbia Plateau tribes, and other agencies. Using Leopold’s Land Ethic principles, I discuss ecological benefits of including lamprey and mussels in ongoing salmonid restoration projects, explore a case study of this in action for a tribal project, and present a call to action for regional restoration practitioners to acknowledge and include the benthic community in river restorations—a “benthic ethic” (Chapter 6).doctoral, Ph.D., Environmental Science -- University of Idaho - College of Graduate Studies, 2020-0
Slightly Serious
No full textMy series of drawings and paintings is an exploration of the awkward moments that we often encounter in our adult lives. The figures are a depiction of the psychological reaction of characters confronting an awkward situation. In other situations, characters are used as case studies for observational jokes dealing with politics, the art world/art history, and American culture.masters, M.F.A., Art & Design -- University of Idaho - College of Graduate Studies, 2020-0
Impact of Wildfire on Annual Water Yield in Large Watersheds
No full textAvailable studies on the effects of wildfire on water yield were conducted in small size watersheds (100km2) have been increasing in the last decades, resulting on the need to predict their impacts on watershed hydrology. The impact of wildfire on watershed annual water yield is constrained by a complex interaction among several processes, which include hydrologic, geologic, ecologic, climatic alterations. This study investigates short- and long-term responses of annual water yield changes due to wildfire in large watersheds within a paired watershed framework. We, also, propose a new theoretical approach based on the Budyko framework to predict the change in annual water yield due to wildfires, which was originally proposed to explore alterations of water and energy balance within burned watersheds. Long-term responses of annual water yield were predicted by analyzing residuals between annual water yields measured in the field and estimated with paired watershed regression models. Paired watershed analyses were applied to 34 pairs between 11 burned watersheds and 8 unburned watersheds in the Salmon River and Payette River basin (Central Idaho USA), Yellowstone National Park (Wyoming, USA), and Klamath River basin (California, USA). The Budyko framework was conducted in 8 burned watersheds for 10 wildfires, were statistically significant from paired watershed analyses. The Budyko framework was applied both at the yearly time scale (one point for each year) and as originally developed as time averaged (one point for pre and one for post-fire period). This study employed (1) a simple linear model with evaporative index (AET/P) and (2) Fu [1981]’s equation with relative evaporative index (1-Q/P). Results show that annual water yield generally increases after wildfires that burned more than 10% of drainage area with negligible and undetectable changes for smaller burned areas. Exceptions to this trend are for watersheds whose hydrological system is dominated by baseflows (with large ground water storage) and those whose wildfire mainly burned short vegetation. Annual water yield tends to return toward pre-fire condition following the Kuczera’s curve, which is related with changes in water demand following regrowth or resuccession of burned trees/vegetation. Post-fire annual water yield increased with burned area, and this correlation was more evident in Mediterranean than in arid climate regions. Post-fire change in annual water yield increases proportionally with drainage area in small watersheds, but this relationship is limited in large watersheds. Results of the Budyko framework show decrease in evapotranspiration rate in most burned watersheds. Reduction in evapotranspiration results in an increase of annual water yield. On the other hand, increase in evaporative index was detected in burned watershed where trees grew quickly during the post-fire period. Climatic conditions can affect the hydrological response during post-fire. Weather condition is an important factor for estimating the annual water yield responses against wildfire. Budyko framework shows that wildfire impact is mitigated under wet weather condition or enhanced under dry weather condition. Results of paired watershed analysis and Budyko framework show a good agreement that post-fire annual water yield responses are strongly correlated with changes in evapotranspiration rate associated with tree mortality or regrowth rate.doctoral, Ph.D., Civil Engineering -- University of Idaho - College of Graduate Studies, 2020-0
Electrophysiological Characterization of Mesenchymal Stem Cells Differentiating into Tenocytes via Dielectrophoresis
No full textTenocytes or tendon cells are the primary cells of a tendon that are responsible for holding a muscle and a bone, and are found throughout the body from head to the feet at several muscle bone joints such as collar bone, hip joint, knee, etc. It is also a major component of the musculoskeletal system. Tendons are susceptible to injuries such as tendinitis, tendon rupture etc., due to the effects of aging and stress. Stem cell based therapies offer alternative methods to treat such conditions. Among various types of stem cells, mesenchymal stem cells (MSCs), a type of multipotent stem cell, are known for their ability to regenerate and differentiate to tendon lineages. Undifferentiated MSCs derived from the bone marrow of a mouse, are characterized to obtain dielectric properties (i.e., conductivity and permittivity) of their outer membrane and cytoplasm using the dielectrophoretic crossover frequency technique. Undifferentiated MSCs are then treated with growth factors to induce differentiation (tenogenesis) into tenocytes and are dielectrically characterized at several time points. In this thesis, we chose to explore the day-3 time point of differentiation to detect changes in the membrane and cytoplasm along with undifferentiated cells aged to day-3 as control samples. Experimental results are statistically analyzed for their reproducibility and are modeled using a single shell model to quantify the dielectric properties. It is observed that the electrical nature of the cells significantly varied through their course of differentiation, which will be utilized to serve as a label-free biomarker for sorting the differentiated MSCs from the undifferentiated ones. Sorted differentiated cells can then be used in stem cell based therapy without resulting in post-treatment complications such as tumors. The designed stem cell sorter via dielectrophoresis (DEP) in a label-free way avoids complications involved in the current separation techniques such as FACS and MACS.masters, M.S., Chemical and Materials Science Engineering -- University of Idaho - College of Graduate Studies, 2020-0
The Physiological Response of Conifers to Fire
No full textOne of the grand unknowns of ecosystem science is how fire kills trees. Answering this question is critical to parameterize climate-vegetation models given the observed changes in global fire regimes, the feedbacks between fire and forests in the global carbon cycle, and the potential role of forest management in moderating anthropogenic climate change. In this dissertation I conducted three studies using Pinus ponderosa saplings burned under controlled conditions to improve the understanding how fire effects on tree physiology. First, I assessed the impact of two fire intensities on sapling mortality under two water status pre-fire (well-watered and drought-stressed). The results showed that saplings under drought-stress pre-fire were more vulnerable to mortality when exposed to low fire intensities. However, 100% of mortality was observed regardless of the pre-fire water status when saplings were exposed to high fire intensity. Thus, the data also suggest that there is a fire intensity threshold where the pre-fire water stress can have a significant influence on sapling mortality. Second, we investigated the short (one-day post-fire) and long-term (21-months post-fire) effects of fire on sapling water transport. In the short-term, fire did not have impact on sapling xylem hydraulic conductivity or were more vulnerable to drought-induced embolism. However, in the long-term, saplings were more vulnerable to cavitation. But no damage in the xylem conduits cell walls were observed. Thus, it was hypothesized that the new traumatic xylem formed in the edges of the fire scar and the pre-fire xylem clogging with resin could be responsible for increasing vulnerability to cavitation in these plants. Lastly, I evaluated the impact of a lethal fire intensity on sapling hydraulic conductivity and non-structural carbohydrates periodically for 28-days post-fire. Hydraulic conductivity was not affected any day. This confirmed the results found in the second study. Fire caused a decline in total NSC in burned plants compared with unburned saplings, but it was significantly only 28-days post-fire. The results suggest that tree mortality from fire is likely not due to hydraulic failure but may be related to carbon imbalance.doctoral, Ph.D., Natural Resources -- University of Idaho - College of Graduate Studies, 2020-0
Soil Disturbance Recovery After Timber Harvests on the Malheur National Forest, Oregon
No full textSoil productivity is essential to the sustained production of ecosystem goods and services and monitoring the impacts of land management is critical for ensuring the continuation of productive forests. The National Forest Management Act of 1976 (NFMA) mandates monitoring soil property changes following management practices at all national forests, so they “will not produce substantial and permanent impairment of the land”. The Forest Soil Disturbance Monitoring Protocol (FSDMP) was developed by the U.S. Department of Agriculture Forest Service (USFS) to ensure a standard method for collecting pre- and post-harvest soil monitoring data. Data collected following the FSDMP provide temporal and spatial insights into soil recovery rates and alteration of soil processes or hydrologic function following disturbance. The objective of this study was to 1) identify site factors and operational harvest impacts that alter dynamic soil properties, and 2) outline best management practices that account for these site and operational factors. Prior harvested stands on the Malheur National Forest in northeastern Oregon, USA were identified to reflect a range of soil types, climatic conditions, past timber harvest mechanisms and seasonal timing, as well as topographic position (slope, aspect). Fifty-one stands were selected within a project area approximately 31,000 hectares and monitored retrospectively to evaluate soil disturbance and site characteristics that influence soil recovery from timber harvests completed within the past 5, 10, 20, or 40 years ago. We found that clay and silt content, spring moisture deficit, fall mean maximum temperature as well as interactions between clay x silt content, depth to restrictive layer x coarse fragment content, and silt x depth to restrictive layer had the most influence on soil disturbance. Important management considerations are (1) harvest operations that occurred during winter months resulted in less soil disturbance, (2) greater clay content (relative to silt content) decreased the amount of soil disturbance, and (3) soils show a trend toward recovery 10-years after harvest operations are complete.masters, M.S., Plant, Soil and Entomological Sciences -- University of Idaho - College of Graduate Studies, 2020-0
Evaluating Field-Based Grazing Intensity Measurements for Adaptive Rangeland Monitoring
No full textA diversity of field-based grazing intensity measurements are used for rangeland management. However, there is a lack of acknowledgement that the choice of method and their implementation may influence the precision, accuracy and sensitivity of grazing intensity estimates. Improved understanding of the sources of variation and bias within grazing intensity estimates can improve planning of monitoring programs, increase use of more appropriate methods for a given situation, and improve the ability of data to inform management. I evaluated and compared several methods for measuring utilization and grazing intensity in two semi-arid grassland and shrubland ecosystems: the pacific northwest bunchgrass prairie and sagebrush steppe. Utilization methods were also compared to actual stocking rates and locations of livestock using GPS data. A multiple-regression approach used to attribute variation in grazing intensity estimates found a significant proportion of variation was related to observer’s recent experience and training, particularly with visual estimation methods. Other sources of variation in utilization estimates included plant composition and cover. Calibration techniques which used in-field estimates of utilization from quantitative measurements were able to improve the relationship between visual estimation methods and livestock GPS-based grazing intensity estimates. Different methods produced significantly different estimates of mean utilization at both fine and broad scales however correlation between methods and actual stocking rates increased at broader scales. Results suggested improvements to the implementation and design of rangeland monitoring including consideration of observers’ recent experience, increasing site-specific training and using sample designs which represent the fine scale spatial variation in grazing intensity and vegetation cover. Improved understanding of the relative limitations of different rangeland monitoring methods creates capacity to leverage the growing trend in citizen science and provides an opportunity for increased flexibility and resilience in rangeland management.masters, M.S., Natural Resources -- University of Idaho - College of Graduate Studies, 2020-0
A Novel Puncture Method for Determining Plant Stem Morphology and Lodging Resistance
No full textBackground Maize (Zea Mays L.) is one of the most extensively grown crops in the world. Due to lodging, or plant destruction caused by high wind and rain, 5% to 15% of the annual global crop is lost. Developing maize hybrids that exhibit high lodging resistance could increase food security and decrease the risk of crop loss. A new method of predicting stem lodging resistance is presented in this thesis. Results A novel rind puncture technique was used to obtain measurements of rind thickness and diameter for samples of poison hemlock that were highly correlated with caliper measurements and photographic image analysis measurements. Higher sample throughput was demonstrated by the novel rind puncture technique than by caliper measurements and image analysis techniques. The data generated by the novel puncture method was used to calculate an index quantity (the Integrative Puncture Score) that was highly correlated with stem failure load in maize. Conclusions The novel rind puncture technique shows promise as a high throughput method for determining rind thickness and diameter. The technique is an excellent candidate for direct implementation in the field. The Integrative Puncture Score shows promise as a breeding metric for producing lodge resistant maize hybrids.masters, M.Engr., Mechanical Engineering -- University of Idaho - College of Graduate Studies, 2020-0
Nutrition Intake and Child Feeding Styles Among Latino Farmworkers in Southern Idaho to Childhood Obesity
No full textChildhood obesity is a health concern in the United States (US); obesity among children of Migrant and Seasonal Farm Working (MSFW) families exceeds that of other US Latino children. Childhood obesity is impacted by several factors; however, a crucial factor is parenting influences. Child nutrition intake and child-feeding styles have been associated with children’s weight status. As a result, knowledge about family’s dietary quality is needed to understand the parental role in the origins and prevention of child obesity in MSFW families. A secondary qualitative study was conducted to investigate the MSFW families’ perspectives on their feeding styles, nutrition intake, and their children’s Body Mass Index (BMI). This study attempted to characterize the association of feeding styles to dietary intake and measure overweight and obesity status in MSFW children. A convenience sample was used from the existing data (N=384) from the Community Council of Idaho, Migrant and Seasonal Head Start (MSHS) Programs in Idaho. The data were obtained from families and children, ages 3-5 years of age attending MSHS centers. The method of data collection that is used for this project included anthropometric measurements to conduct children’s height and weight and the nutrition history questionnaire answered by families. The results were analyzed using SPSS software by coding the responses to the nutrition history questionnaire numerically. The results indicated that most of the families in this study reported similar child-feeding styles and perspectives on child nutrition intake across different child weight status ranging from underweight to obese. A similar pattern was found in parental reported child-feeding styles and parents’ perspective on child nutrition intake to children’s BMI. This study adds to the literature because it was one of few studies using the parental self-report method to gain understanding on MSFW child feeding styles and children’s food intake. Understanding how feeding styles influence children’s eating behaviors can benefit prevention programs, specifically those that aim to prevent childhood obesity and to help parents understand effective feeding styles.masters, M.S., Family and Consumer Sciences -- University of Idaho - College of Graduate Studies, 2020-0