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Using site-specific weather information and canopy sensing to support disease management in Idaho vineyard
No full textWeather dictates farm operations including irrigation scheduling, harvesting, and protection from crop damaging events such as frost, heat waves or disease outbreaks. In a changing climate, it is imperative that farmers are equipped with tools to efficiently and sustainably produce crops with limited resources. Farmers need real-time and site-specific weather data in order to better inform planning and resource allocation. Currently, regional weather networks provide near real-time data in most locations throughout the continental US, but these data may not represent local conditions for most locations. This thesis will focus on the development of low-cost weather stations using the Arduino-platform and describe their application to enhance management decisions in an Idaho vineyard. The low-cost weather stations showed robust results in calibration and were capable of testing rigorous hypotheses about site-specific weather phenomena. As a result, we show how site-specific weather data can answer questions that are directly relevant to disease management. Vineyard canopies are also surveyed using a field spectroradiometer and infrared thermometer to show spatial and temporal patterns of plant physiological response to their environment. A synthesis of socio-economic concerns that may impede the use of weather-based decision support tools is provided, and challenges associated with integrating weather into farm operations are discussed.masters, M.S., Water Resources -- University of Idaho - College of Graduate Studies, 2020-0
Procedural Content Generation via Diversity Engines
No full textAsset generation in video games and simulations is an expensive process that takes considerable resources to do well. Procedural Content Generation (PCG) is a technique that can be used to generate this content for video games and simulations. Although, there are certain flaws related to content quality and diversity that need to be addressed in order to utilize this technique generally. The Innovation Engine is a relatively new theoretical framework that is incrementally attempting to encapsulate human creativity by computational means. Optimizing techniques such as Genetic Algorithms (GAs) are inadequate when trying to accomplish goals related to creativity. A new software framework presented in this work, the Diversity Engine, acts as a practical application of the ideas found in Innovation Engines and shows procedurally generated flowers can be created, with mixed results, using a new Quality Diversity (QD) algorithm Centroidal Voronoi Tessalation MAP-Elites (CVT-MAP-Elites).masters, M.S., Computer Science -- University of Idaho - College of Graduate Studies, 2020-0
53rd Annual Lionel Hampton Jazz Festival Program
No full textEvent program. Includes artist biographies, concert schedules, performance schedules, workshop and clinic information, and sponsor information
53rd Annual Lionel Hampton Jazz Festival Poster
No full text24"x18" limited edition poster, number 11/15
Corrosion and Electrocatalytic Behaviors of Additively Manufactured INCONEL 718 Alloy in pH Adjusted 3.5% NaCl Solutions at Room Temperature
No full textINCONEL 718 is a heat treatable Ni-Fe-Cr-Mo alloy used in a wide range of temperatures (23 – 977 K) because of its superior strength, toughness, and resistance to creep and corrosion. It is a material of choice for components of aircraft engines, gas turbines, oil drilling equipment, nuclear reactors, cryogenic tanks, heat exchangers, and liquid fueled rockets. Additive manufacturing (AM) techniques are implemented to manufacture near net shape components out of INCONEL 718 because of the complexity of design of the components and to minimize the machining cost. Selective laser melting (SLM) is one of the AM techniques which uses a laser beam to selectively melt a layer of alloy powder. The layered melting helps build the required 3D shape of a component. The high energy density melting also leads to very high cooling rates in the order of 106ºC/s. Therefore, SLM process results in isotropic, fine grained microstructures with metastable phases that are not usually obtained in conventional manufacturing processes such as casting or forging. The objectives of this study are to: a) evaluate the corrosion behavior of additively manufactured INCONEL 718 in 3.5% NaCl solutions with varying pH (1.25, 6.25, and 12.25) and correlate with different microstructural conditions obtained by hot isostatic pressing (HIP), and two-step aging treatments; b) compare the corrosion resistance of the additively manufactured material with the conventional wrought material, and c) investigate the electrocatalytic behavior of AM-718 material for hydrogen and oxygen evolution reactions for possible applications as electrodes in water electrolyzers.Cyclic polarization, potentiostatic, and electrochemical impedance spectroscopy measurements were carried out on the INCONEL 718 alloy specimens in four different microstructural conditions. The results showed that the as-printed specimens showed better corrosion resistance than the wrought material in the acidic chloride solution. HIP specimens exhibited superior corrosion resistance to the as-printed ones. Heat treatment resulted in a reduction of overall corrosion resistance. The Tafel slopes for the HER were higher in the as-received samples compared to their heat-treated counterparts in all the pH conditions with samples tested in a basic environment showing the lowest Tafel slopes. The room temperature corrosion properties are relevant for oil field applications, and electrochemical machining of Inconel 718.masters, M.S., Chemical and Materials Science Engineering -- University of Idaho - College of Graduate Studies, 2020-1
Novel remote sensing approaches for monitoring seasonal and ephemeral water resources
No full textSeasonal and ephemeral surface water resources are essential to human consumptive uses and the nourishment of aquatic habitats, but they are increasingly threatened by climate-change related impacts. Western North America, for example, has already experienced significant declines in seasonal snow cover, which will have a range of effects on both human communities and aquatic ecosystems like wetlands. The swift rate of change requires consistent monitoring at scales that support adaptive management, but seasonal-ephemeral water resources are often distributed across vast areas that are poorly instrumented. As such, remote sensing is increasingly employed to monitor freshwater resources and understand hydrological processes. This dissertation investigates the application of novel remote sensing approaches to important questions involving the monitoring of seasonal snow supplies and snow-dependent, ephemeral wetlands. Also included is a study examining the socio-ecological context for climate change research and adaptation in the headwaters regions of a large watershed. The first research chapter explores the potential of using terrestrial laser scanning (TLS) for the estimation of intercepted snow masses on trees. The findings indicate good agreement (R2 = 0.69, RMSE = 0.91 kg) between TLS estimates of snow mass and measurements made on trees suspended from load cells. With further refinement, this approach may prove to be a useful tool in calibrating snow interception models to different forest types. The second research chapter utilizes this new technique to fit a Random Forest model that predicts snow interception volume from a suite of canopy metrics derived from aerial laser scanning (ALS). The findings demonstrate good agreement (R2 = 0.65, RMSE = 0.52 m3) between observations and model predictions and identified the best suite of predictors. This suggests that metrics capturing the intrinsic, three-dimensional variability of tree canopies may be useful as new parameters in hydrological or snow interception models. The third research chapter analyzes a thirty-year time series of satellite imagery to identify trends in ephemeral wetland (playa) inundation, with the goal of informing land management practices and wetland restoration planning. The findings indicate that localized weather conditions and hydrologic modification history are important drivers of playa inundation, that reductions in habitat availability and inundation duration should be expected with intensifying droughts, and that a small number of playa have the potential to function as hydrologic refugia during drought years. The fourth research chapter analyzed the spatial and topical distribution of climate change research in the headwaters of the Columbia River Basin. The findings identify broad patterns in a large body of research, such as gaps in interdisciplinary and geographic collaboration, and suggest future directions for understanding climate change across the region. All told, this set of studies adds to the body of knowledge on remote sensing for seasonal-ephemeral water resources, as well as applications for water resources research and management.doctoral, Ph.D., Water Resources -- University of Idaho - College of Graduate Studies, 2020-0
Dynamic Adsorption Studies of Organic Iodine Species on Mordenites
No full textOff – gas stream from used nuclear fuel recycling operations comprises of various contaminants such as 3H, 14C, 85Kr, 131I, and 129I. Radioactive iodine, 129I, is of significant concern due to its tendency to form hard-to-capture toxic volatile organic compounds such as methyl iodide, half-life in excess of 15 million years, and tendency to accumulate in human thyroid glands. It also has adverse impacts on the environment due to its toxic nature. Organic iodides can be hazardous even at ppb level concentrations, and hence the capture of 129I is extremely important. Various methods such as absorption and adsorption have been employed in the past to capture volatile iodine species. Recent studies have been focusing on the adsorption of iodine species using solid porous adsorbents, and the current work involves the capture of organic iodine species on mordenites. The off-gas environment was simulated using ppb level concentration of iodine species and the dynamic adsorption experiments were conducted to determine the efficiency of mordenites as adsorbents. Three different mordenites - sodium mordenite, partially exchanged silver mordenite, and fully exchanged silver mordenite were used as adsorbents. The silver mordenites were synthesized by ion exchange between silver nitrate solution and sodium mordenite and subjected to structural and compositional analysis. Adsorption-desorption cycles at different temperatures and using different materials of construction for the column were conducted and the effect of silver content on the adsorption capacity of sorbents was determined. The sorption columns exhibited behavior atypical of pure adsorption with no breakthrough and exhaustion of the adsorbents. It was hypothesized columns were behaving as reactors operating at a steady-state. Kinetic analysis of the system was conducted incorporating the effects of diffusion and mass transfer. The analysis indicates that a second-order reaction was the rate-controlling mechanism for methyl iodide removal. These research findings could give good insights about the behavior of volatile organic iodine species at lower concentrations and their effective capture.masters, M.S., Chemical and Materials Science Engineering -- University of Idaho - College of Graduate Studies, 2020-1
Escherichia coli exhibits single-cell heterogeneity in phenotypic tolerance to formaldehyde that is unrelated to persistence
No full textThe phenomenon of phenotypic heterogeneity, where a clonal population expresses varying phenotypes has been reported across a wide variety of organisms, and many of an organism’s traits may exhibit this heterogeneity. Heterogeneity is often phyisologically relevant, allowing the clonal population to divide the labor of metabolic (or other) tasks, or to maintain more resilient subpopulations that can survive stressors that kill the bulk of the population. Recently, it was discovered that Methylorubrum extorquens, a facultative methylotroph, possesses heterogeneity in tolerance to formaldehyde, a toxin produced by M. extorquens during growth on methanol. Surprisingly, transcriptomic data indicated that genes responsible for methylotrophy are not responsible for enhanced tolerance to formaldehyde demonstrated by the resistant subpopulation, but rather that more general mechanisms such as protein repair via chaperonins are responsible. This suggested that this heterogeneity may be present even in organisms that do not produce large quantities of formaldehyde during routine metabolism, and thus be widely distributed across bacteria. To investigate this, I tested Escherichia coli for heterogeneity, and compared its survival and growth dynamics to those of M. extorquens. It was determined that E. coli does indeed show heterogeneity to formaldehyde stress, however, there are some major differences in how this heterogeneity affects growth dynamics. It was further hypothesized that due to the nature of some of these differences this tolerance may be the result of persistence, a condition where a viable cell temporarily ceases division, a state that is widely reported to allow the cell to avoid damage from a broad variety of stressors. Experiments determined that this was not the case, however, these same experiments suggested that these persister cells can maintain memory of the environments that they were in during their entrance into a persistent state. This implies that persistence is a form of phenotypic heterogeneity that itself preserves other dimensions of heterogeneity, a concept which to my knowledge has not been previously described.masters, M.S., Biology -- University of Idaho - College of Graduate Studies, 2020-1
The Effects and Implications of Oxidation on Nuclear Grade Graphite
No full textGraphite is an important and often life-limiting component for reactors. It is used as a structural and moderating material in both research and commercial high-temperature gas cooled reactor designs. Prior to use in a reactor, the physical, mechanical, and thermal properties of the selected graphite grade must be assessed to evaluate the in-service performance over the life of the component. While graphite is inherently stable in the inert environment of a helium-cooled reactor during normal operations (anticipated 400–1000°C core temperature), graphite is susceptible to rapid oxidation when exposed to oxidizing conditions at these operating temperatures. The concern with oxidation is its impact on the physical, mechanical, and thermal properties of graphite. Changes to the structural integrity of the core components is the most critical issue for reactors, meaning the changes in mechanical strength of graphite must be determined for a variety of oxidizing conditions. Also critical is the impact of oxidation on physical and thermal properties, a decrease in the density of graphite due to oxidation for example will decrease neutron moderation. Additionally, the rate of heat removal from fuel will be impacted as the thermal diffusivity will decrease with oxidation.The strength behavior of fine- and medium-grain nuclear graphite grades are examined following exposure to varying oxidizing conditions within the kinetic regime as defined by the ASTM oxidation test standard 7542. This study addresses the critical licensing issue of remaining oxidized strength of graphite core components after oxidized mass losses up to and beyond the current limits recommended within the ASME Boiler and Pressure Vessel (BPV) code (implied maximum mass loss = 10%) over a range of oxidation temperatures from 550°C to 750°C. Preliminary results generally demonstrate that low-temperature oxidation can result in 30% greater strength reductions than is seen during oxidation at higher temperatures with similar mass-loss levels. These results have implications in the way the ASME BPV code is currently interpreted, as there is no provision for the oxidizing conditions which were found to have a significant effect on the strength of graphite after oxidation. Property changes of fine- and medium-grain nuclear graphite grades are examined after subjection to uniform oxidation conditions within the kinetic regime as defined by the ASTM oxidation test standard 7542. This study addresses the underlying physical property changes of nuclear-graphite components for oxidized mass losses beyond the current limits recommended for graphite components in the ASME code. Property measurements include density, elastic modulus, shear modulus, coefficient of thermal expansion, electrical resistivity, and thermal diffusivity. Results demonstrate a decrease in elastic modulus and thermal diffusivity, and an increase in electrical resistivity and coefficient of thermal expansion with increasing oxidation mass loss. The decrease in coefficient of thermal expansion contradicts previous work due to differing oxidation regimes and highlights a need for clarity in the ASME Boiler and Pressure Vessel code on the way oxidation occurs.masters, M.S., Mechanical Engineering -- University of Idaho - College of Graduate Studies, 2020-1
Quantifying Burn Severity Patterns and Post-Fire Recovery
No full textFire plays an important role in shaping landscape patterns and ecological processes in many ecosystems across western North America. Burn severity is a primary measure of the ecological change caused by fire and differing levels of burn severity can in turn result from the interaction of landscape patterns, ecological processes that have created differing fuel loads and continuity, and abiotic factors such as climate and slope. Understanding how burn severity impacts ecosystem recovery post-fire can therefore inform both future recovery and management planning but also the resulting landscape patterns and processes that can influence future fires. This dissertation examined how burn severity and spatial patterns of differing burn severity levels impacted long-term (9-15 years post-fire) ecological processes in ponderosa pine (Pinus ponderosa) and boreal spruce forests (Picea glauca/Picea mariana). Specifically, the chapters addressed 1) how two contrasting landscape models derived from high resolution satellite imagery captured burn severity patterns in a ponderosa pine forest and how those patterns related to post-fire processes (distance to live tree, seedling density, understory species richness) on the Egley Fire Complex (OR); 2) how burn severity and associated biotic and abiotic factors (e.g., tree density, understory green cover, soil cover, downed woody fuel) interacted with climate and site factors (e.g., elevation, soil productivity) to influence ponderosa pine seedling density and height growth on three fires across the western contiguous US (Jasper Fire [SD], Hayman Fire [CO], Egley Fire Complex [OR]); 3) how burn severity level, as indicated by a remote sensing index, related to understory species community assemblage and vegetation conditions (e.g., overstory density, surface cover, downed woody fuel load) 12 years after the Taylor Fire Complex (AK) in boreal spruce forest. Examination of high resolution satellite imagery captured shortly following containment of the Egley Fire Complex showed that tree crowns were driving the spatial variability of the landscape, and that both a continuous (gradient) and a categorical (patch-matrix) landscape model produced metrics that related strongly to distance to live tree. Neither model, however, produced metrics that related strongly to seedling density or understory species richness, indicating that potentially even analysis of fine-scale imagery (0.6 m) does not meaningfully capture microsite variation that explains these post-fire processes. Across three ponderosa pine fires, our model showed that burn severity and related factors (percent soil surface cover, fine woody fuel load, and basal area of dead trees) interact to influence the density of seedlings. In contrast, the height growth of those seedlings was influenced by soil productivity, basal area of live trees, and climate (fall degree-days above 5°C and winter evapotranspiration). Finally, 12 years following the Taylor Fire Complex in boreal spruce forest we found that burn severity, as indicated by Landsat-derived delta Normalized Burn Ratio, still significantly impacted tree density, tall shrub cover, and downed woody fuel load. Burn severity also related to significant differences in understory plant community species assemblage and richness, in association with elevation and aspect. Overall our research finds that long-term effects of burn severity continue to be present in these ecosystems and that these effects influence important post-fire processes. This research presents the first use of the gradient landscape model to characterize burn severity patterns and their relationship to ecological processes following fire in ponderosa pine. We further highlight the potential for differing factors to influence ponderosa pine seedling density vs. height growth and the importance of considering height growth when examining post-fire recovery. Finally we show that burn severity inferred from satellite imagery has long-term impacts on vegetation and woody fuels in boreal spruce forest.doctoral, Ph.D., Natural Resources -- University of Idaho - College of Graduate Studies, 2020-1