University of Idaho Library Digital Initiatives
Not a member yet
54971 research outputs found
Sort by
Vertex-Disjoint Large Cycles
No full textIn this dissertation, we discuss cycles of length at least six. We prove that (Theorem 1) if is a graph of order and the minimum degree of is at least , then contains disjoint cycles of length at least six, and (Theorem 2) if is a graph of order and the minimum degree of is at least , then contains disjoint cycles covering all the vertices of such that are 6-cycles.doctoral, Ph.D., Mathematics -- University of Idaho - College of Graduate Studies, 2020-0
Creating invasive plant distribution models for the Greater Yellowstone Ecosystem to meet conservation objectives
No full textThe Greater Yellowstone Ecosystem (GYE) is a unique and intact ecosystem that covers over 8-million hectares across portions of Idaho, Wyoming, and Montana. The GYE has been protected through active management for conservation of lands, waters, and wildlife by the Greater Yellowstone Coalition (GYC) since 1983. The conservation goals of the GYC are currently challenged by invasive plants that reduce forage quality and plant diversity. Susceptibility models within geographic information systems (GIS) can effectively direct ground surveys to locate invasive plant populations when their special extent is small. Early detection of infestations less than one hectare are commonly eradicated. Once an infestation reaches 1,000 hectares it is unlikely to be eradicated, so ongoing containment costs will be necessary. Every dollar spent on prevention can avoid 17 dollars spent on later control which is why early detection is critical. The first chapter of this thesis details construction of new susceptibility models for meadow hawkweed (Hieracium caespitosum) and orange hawkweed (Hieracium aurantiacum) in 1.31 ha of the GYE using known locations of each species with aspect, slope, precipitation, and Sentinel-2 satellite spectral data. Models were used to select transect locations within susceptible areas for plant cover acquisition to identify indicator species and habitat types. Approximately 662,000 ha were determined to be susceptible to meadow hawkweed and 436,000 ha were determined to be susceptible to orange hawkweed, representing 51% and 33% of the study area, respectively. Forty-three 20-meter transects were surveyed; seven indicator species of meadow hawkweed and three indicator species of orange hawkweed (two of which were indicators of both) were identified. Transects were in 10 different habitat types within predicted orange or meadow hawkweed susceptibility. Eight habitat types were shared by both species but only meadow hawkweed was predicted in the big sagebrush/Idaho fescue type and only orange hawkweed was predicted in the Douglas fir/common snowberry habitat type. The second chapter of this study extended susceptibility models created in Idaho, using Idaho presence data for leafy spurge (Euphorbia esula) and rush skeletonweed (Chondrilla juncea) into 1.12 million ha of the GYE. Model extension was used due to few known occurrences of leafy spurge or rush skeletonweed in the GYE that prevent creation of independent GYE models. The environmental variables used for these models were maximum temperature, minimum temperature, sun angle, precipitation, and National Agriculture Imagery Program spectral data. Susceptibility was divided into low, moderate, and high categories (plus a not-susceptible category). Only 105,100 ha (9% of the study area) were predicted to be susceptible to leafy spurge. Rush skeletonweed susceptibility was predicted across 396,500 ha (33% of the study area). Overall, the study area was at a low risk to leafy spurge and rush skeletonweed invasions based on the extension of Idaho susceptibility models. When managing a region as large as the GYE, it is important to prioritize efforts on landscapes at the greatest risk to invasion because funds are often limited, and early detection is critical for successful eradication or control.masters, M.S., Plant, Soil and Entomological Sciences -- University of Idaho - College of Graduate Studies, 2020-0
Rural Schools Around Potlatch and North Latah County
No full textPotlatch Historical Society. Occasional Paper. Rural Schools Around Potlatch and North Latah County. Compiled by Gary E. Strong. The Society. 2020
Design and Improvement of a Real-Time Simulated Microgrid and SCADA System for the University of Idaho Industrial Control System Testbed
No full textOne of the main goals of this thesis is to expand upon a previously created simulation of a microgrid system to better emulate a real-world power system. By doing this, the system can function more dynamically and behave more realistically in test scenarios. The next goal is to implement substation hardware into the loop to simulate a utility SCADA system with network communication for testing the effect cyber-attacks can have on the system's operation. This will allow the testbed to be used to develop measures to detect attacks along with countermeasures to mitigate cyber-attacks and allow the system to recover faster from such attacks. This research project successfully, designed, tested, and implemented improvements to the simulated system including the inclusion of dynamic loads, improved generator controls, and DC storage device. These improvements allow the simulated system to more accurately mimic a real-world power system while remaining within a stable operating region. The project also successfully configured and incorporated of substation equipment to simulate multiple substations along with designing and implementing a SCADA master used by operators to directly control the system from a remote location. This SCADA master consists of a human-machine interface, used to monitor and interact with the system, and a data historian, used to record system data points for future review and analysis. These improvements and incorporated hardware allow for the system to be utilized in future projects relating to system resilience and cyber threat analysis.masters, M.S., Electrical and Computer Engineering -- University of Idaho - College of Graduate Studies, 2020-0
In-Medium Nucleonic Interactions and Chiral Effective Field Theory: Insight into the Nuclear and Neutron Matter Equation of State from Neutron Skins to Neutron Stars
No full textThe goal of microscopic nuclear physics is to describe nuclear structure and nuclear reactions in terms of fundamental forces between the elementary constituents of hadrons. Quantum Chromodynamics (QCD) is understood to be the fundamental theory of strong interactions. In QCD, hadrons are bound states arising from interacting quarks and gluons. Unfortunately, in the low-energy regime QCD is non-perturbative, which renders the theory unmanageable for the description of low-energy reactions and nuclear structure. Chiral Effective Field Theory provides the link between QCD and nuclear forces that are suitable to describe bound nuclear systems and low-energy reactions. While respecting the symmetries of the QCD Lagrangian, the theory adopts nucleons and pions as its degrees of freedom. In this work we use two- and three-nucleon forces constructed from Chiral Effective Field Theory and apply them in nuclear matter. The energy per particle as a function of density in infinite nuclear matter is referred to as the nuclear matter equation of state. Nuclear matter is an infinite system with equal densities of protons and neutrons. More precisely, this is referred to as ``symmetric nuclear matter." Neutron-rich matter is then an infinite system with larger concentration of neutrons, and, of course, pure neutron matter contains only neutrons. The many-body framework we use to evaluate the nuclear matter equation of state is known as the Bruckner-Hartree-Fock approach. Having presented our theoretical tools for the development of the equation of state based on few-nucleon chiral forces (Chapter 2), we proceed to show and apply our predictions. Modern theoretical predictions of neutron-rich matter are particularly timely. On-going and planned experiments aim at measuring observables which are sensitive to the equation of state of neutron-rich matter or pure neutron matter, particularly the neutron skin. Our predictions (Chapter 3) are within presently available empirical constraints. The equation of state of neutron-rich matter has recently been brought to the forefront of nuclear astrophysics due its relevance for the properties of neutron stars. Neutron stars are important natural laboratories for constraining theories of the equation of state, because the mass-radius relationship of these stellar objects has been shown to be sensitive to it. Our calculations and predictions of neutron star radii are presented in Chapter 4. We find them to be in good agreement with recent observational constraints. We conclude this work with our most recent effort, where we calculate the nuclear matter equation of state with the inclusion of subleading contributions to the chiral three-nucleon force. Additional studies related to this development are in progress.doctoral, Ph.D., Physics -- University of Idaho - College of Graduate Studies, 2020-1
Microreactor AGile Non-nuclear Experimental Testbed Aspen HYSYS Analysis
No full textThere is a lot of interest in modular nuclear microreactors and the benefits they bring for mobile power in remote areas and process heat applications (World Nuclear Association, 2020). Many companies in the nuclear power industry are developing various types of reactors, ranging from high temperature gas reactors (HTGRs), sodium-cooled fast reactors, molten salt reactors, light water reactors, and heat pipe cooled reactors. Each reactor type requires different thermal conditions to achieve their most efficient operations. Many of these miniaturized transportable reactor designs remain largely untested and unproven. To aid in the development of the miniaturized reactors, Idaho National Laboratory (INL) is developing a Microreactor AGile Non-nuclear Experimental Testbed (MAGNET). The MAGNET will be used to simulate the thermal conditions (pressures, temperatures, heat transfer fluids, etc.) that microreactors are expected to deliver. The MAGNET facility will accommodate various electrically heated microreactor prototypes. However, the first reactor type under consideration is a heat pipe cooled test article. The working fluid being considered to cool the heat pipes in the MAGNET system is nitrogen or helium with a max operating temperature of 600°C. To help in the development of the MAGNET facility, models were developed in Aspen HYSYS (Aspen Technology, Inc., 2016) to approximate the thermal conditions throughout the test loop.The MAGNET models created could be used to simulate the experiments and potential experiments for the MAGNET. This could save time and money by reducing the number of costly experiments that provide little information. It could also be used to simulate off design conditions to determine safety parameters that could be potentially dangerous, like extreme pressures or temperatures. From the analyses, it was shown that the upper end temperature while using helium could reach close to 635°C. This approaches the upper limit of the piping at 650°C, making helium potentially dangerous unless changes are made to the mass flow rate or heat pipe power load. The models also showed a detailed pressure drop throughout the system showing that the MAGNET’s compressor could handle the required pressure ratio. However, it also showed concern about the compressor handling the required mass flow rates. Another major application drawn from the HYSYS models was a representation of the heat loss and temperature loss throughout the piping. This showed that the heat loss from the piping was minimal when the power applied to the heat pipes was at least greater than 75 kW. Modular nuclear microreactors generate power using various power conversion units (PCUs). Several common PCUs include steam Rankine cycles, air Brayton cycles, closed helium Brayton cycles, recuperated Brayton cycles, supercritical carbon dioxide cycles, and organic Rankine cycles. Combined power cycles can also be used to increase the thermal efficiency of the PCU. Combined cycles could include a Brayton cycle with a steam Rankine bottoming cycle. An advantage of the MAGNET is having the ability to easily attach a PCU to the MAGNET. Two options were considered for adding a PCU to the MAGNET. The first option was to find a physical PCU unit to attach to the test loop and the second option was to develop a PCU simulator. The MAGNET HYSYS models were designed with a compressor and turbine to model a PCU. The configuration made was a recuperated Brayton cycle. The cycle was optimized by varying the outlet pressure of the turbine to achieve the highest thermal efficiency of 8.57% with nitrogen and 15.5% with helium. A PCU simulator was also designed from the research that Brayton cycles can be uniquely identified by three state points and knowing the pressure ratio. The PCU simulator simulates simple and recuperated Brayton cycles using a series of heat exchangers and valving. The major advantage of the PCU simulator was that it could simulate various Brayton cycles under various compressor and turbine efficiencies. However, the major disadvantage was that the system has be large capital cost estimated near 2.15 million dollars. A simple Brayton cycle start up process was analyzed to provide understanding for the start- up process of a nuclear powered Brayton cycle. The data provided an upper limit for realistic compressor and turbine adiabatic efficiencies of 85% and 90%, respectively. From the analysis, the three key state points were collected which would allow the PCU simulator to simulate start up processes. An understanding for how a nuclear powered Brayton cycle could start up was also learned from the analysis. One could say that the nuclear powered PCU start up is similar to a conventional natural gas PCU except when the start up process begins. The nuclear reactor would be at operating temperatures before the PCU started. Then the heat could be applied to the PCU instantly instead of at conventional timing in natural gas PCU. This thesis details the development of the Aspen HYSYS MAGNET model as well as the development of the PCU simulator, including cost estimates and start up analysis.masters, M.S., Mechanical Engineering -- University of Idaho - College of Graduate Studies, 2020-1
APPLICATION OF YELLOW PEA (PISUM SATIVUM) FLOUR INTO BAKED GOODS
No full textLegumes and pulses are increasingly viewed as a superfood and sustainable future protein source. Yellow pea flour produced in large quantities in North America is high in protein and fiber, and low in lipids. The objective of this thesis is to study the effect of incorporating dry split yellow pea flour into baked goods like bread and pancakes and identify the threshold of maximum incorporation at which physical and sensorial attributes are not affected significantly. The section titled “the physical and sensorial characterization of yellow split pea flour incorporated pancakes” in the thesis tested the effect of pea flour addition on pancake physical and sensorial properties by instrumental analyzes and a trained descriptive panel at levels of 1%, 2%, 5%, 10%, and 20% w/w basis. Sodium metabisulfite (SMB) was added as the reducing agent to evaluate the hypothesis that changes to protein conformation will impact the flavor profile of the pea flour. All the pancake batters prepared with pea flour, with pea flour and SMB, and with only SMB were optimized to have the same viscosity. It was observed that viscosity optimization was advantageous in attaining pancakes with similar physical attributes, like height, weight, and diameter. There were no significant differences in the measure of weight, height, and specific volume of pancake amongst all the treatments with the value of control at 244.73 g, 2.22 cm3/g, and 4.97 cm, respectively. However, the deviation was not avoidable at a higher level of pea flour incorporation (i.e., 20%) for diameter and texture, which ranged from 12.18 to 13.13 cm and 2637.52 to 3316.86 g, respectively. Sensory attributes did not show any drastic improvement with the addition of SMB. Nevertheless, some interesting observations on the overall sensorial attributes of pancakes were made. The “Incorporation of yellow pea flour into white pan bread” section of this thesis investigates the bread quality of pea flour incorporated bread. Pea flour was added at 1%, 2%, 5%, 10%, and 20% levels, and the resulting bread was evaluated for the physical and sensory quality. For sensory analysis, control (100% wheat flour), 5%, and 20% of bread were made and evaluated by a consumer panel. It was observed that the bread made with 10% pea flour was not significantly different from control in terms of height, specific volume, and firmness. Bread incorporated with 5% and 20% pea flour was not perceived to be different by the consumer panel. However, the control was significantly different for flavor, after-taste, willingness to buy, and overall acceptability from the pea flour incorporated treatments. On the other hand, control was similar to 10% pea flour bread in terms of texture and appearance. The panelists were not able to differentiate between the appearance of the bread across all treatments.masters, M.S., Food Science -- University of Idaho - College of Graduate Studies, 2020-0