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Communications and Attitudes Across Jurisdictional Lines During Post-Fire Ecological Restoration Collaborations
No full textWildfire seasons are changing from a seasonal and typical management season to a year-round global problem. Magnifying this change is a dramatic uptick in uncharacteristic catastrophic wildfire trends. These fires are responsible for decreases in local wildlife populations worldwide and a multitude of other societal issues due to increases and redistribution of human populations resulting in an ever-expanding Wildland Urban Interface (WUI). In the United States there are multiple land management agencies working within differing ecological landscapes that manage wildfire and ecological restoration pre-and-post-wildfire. There are no overarching management rules for all agencies pertaining to post-fire ecological restoration aside from the National Environmental Policy Act (NEPA), so we examine what management gaps exist due to the patchwork of management across the United States. Our study analyzed survey data (n=80) from diverse employees involved in post-fire ecological restoration efforts. Survey participants include employees from state, federal, private, tribal and nongovernmental organizations. Our goal was to examine the attitudes and perceptions of each agency towards one another with respect to their fire management and restoration methods. We observed complicated results based on each agency’s unique perceptions, organizational ideologies, values and opinions about ecological restoration post-wildfire and how interjurisdictional fire events impact restoration and the decisions made during ecological restoration. The results suggest that despite many of these agencies being near or even next to one another or having overlapping collaboration efforts (meaning potentially being in close enough proximity to be on ecologically similar landscapes despite differing management methods) the methods used during post-wildfire ecological restoration vary depending on what jurisdiction a manager is currently working under. This complicates the restoration process during large-scale fire events. Further, the results suggest that the opinions of those surveyed in differing agencies can depend on what jurisdiction they currently belong to. Based on this research, we suggest multi-agency collaboration specifically with more frequent and/or effective communication that is specific to each agency’s needs. This will emphasize the importance of working across the landscape’s jurisdictional boundaries and accommodating each agency’s differing policies and goals within of times fragmented ecosystems.masters, M.S., Natural Resources -- University of Idaho - College of Graduate Studies, 2021-0
Demonstration of the Feasibility of an Acoustic Flow Meter Utilizing Edge Tone Phenomena
No full textThe research described herein explores the development of an acoustically driven flowmeter for use with liquids in extreme environments; with a specific interest of applicability for use in nuclear reactors such as Molten Salt, Molten Sodium, and High Temperature Gas Reactors. The environments in these reactors are extremely hostile, especially to the sensitive electronics that are typically required of sensory equipment. The acoustic signal generation component of the flow meter is solid state, void of moving parts and electronics, and can be either machined or 3D printed from virtually any material, thereby offering suitability to practically any single phase fluid and environ- ment. Acoustic signals are allowed to propagate through the pipes, fittings, and structural framework where they are measured using piezoelectric sensors some distance from the device, allowing the sensitive electronics to be safe from harmful conditions. The flow meter utilizes edge tone phenomena which produce a tone in which frequency is dependant on the volumetric flow rate through the device. The device was tested on a test loop where temperature and actual flow rate (measured with a Coriolis flowmeter) were controlled allowing generated frequencies to be correlated with their respective flow rates. The flow meter was tested with both water (30 ◦C) and Therminol 66 (100 ◦C) to provide the necessary data for the non-dimensional analysis which relates the flow rate, fluid properties, and geometry of the device to the tone produced by the flow meter.masters, M.S., Mechanical Engineering -- University of Idaho - College of Graduate Studies, 2021-0
Applying Omics Techniques to Uncover Polyhydroxyalkanoate (PHA) Feast-Famine Metabolisms by Mixed Microbial Consortia Cultured on Fermented Dairy Manure
No full textPolyhydroxyalkanoates (PHAs) are bacterially synthesized polymers that exhibit thermoplastic material properties when desiccated. PHA can be synthesized by mixed microbial consortia (MMC) cultured on volatile fatty acid (VFA)-rich wastewater. However, with an ultimate aim to achieve commercial PHA production using MMC and wastewater, much remains to be understood about critical metabolisms to maximize polymer production. This research aimed to characterize metabolomes within undefined mixed microbial consortia (MMC) to better understand what factors inhibit and/or enhance the efficient conversion of volatile fatty acids (VFAs) into polyhydroxyalkanoate (PHA). LC/MS-based targeted metabolomics methods were applied to uncover “feast” PHA metabolisms of MMC cultured on fermented dairy manure; “feast” metabolisms induced under aerobic dynamic feeding (ADF) remain poorly understood, with only limited molecular-level exploration. Preliminary metabolomic data helped illustrate potentially important biochemical pathways of PHA synthesis such as the glycolysis pathway, and describe correlated metabolites present in the MMC metabolome. Results enhance understanding of MMC cultured on real wastewaters, MMC metabolome dynamics when synthesizing PHAs, better describe the feast-famine response, and identify critical metabolites involved in PHA synthesis.masters, M.S., Environmental Science -- University of Idaho - College of Graduate Studies, 2021-0
Investigation of Nitrogen-Doped Pseudo Graphite as an Oxygen Reduction Reaction Electrocatalyst and Robust Electrochemical Sensor
No full textThis dissertation discusses the nitrogen modification of GUITAR (Pseudo-Graphite from the University of Idaho Thermalized Asphalt Reaction). Different methods for selectively doping a variety of nitrogen moieties and their characterization are presented in various chapters. Chapter one introduces the material ‘GUITAR’ and presents the motivation for these works. Chapter two discusses the method for selectively doping pyridinic- and pyrrolic-nitrogen groups (with 0.0 % graphitic nitrogen) onto the GUITAR surface. It is herein referred to as N’-GUITAR. Physical and electrochemical characterization revealed that this material makes the robust electrode for oxygen reduction reaction (ORR) via four-electron pathways, which is desirable for fuel cell applications. The material exhibited high performance and excellent stability than any other carbon materials reported in the literature. Chapter three presents the method for synthesis of N-GUITAR, which comprises predominantly graphitic nitrogen(72.6%). Like N’-GUITAR, this material retains basic characteristic features of GUITAR but demonstrated robustness toward electrode fouling by air aging and polymerization of matrix components during dopamine detection. Application of later form of selectively nitrogen-doped GUITAR (N-GUITAR) for ORR is discussed in chapter four. This material efficiently reduces oxygen to hydrogen peroxide via two-electron pathways. It exhibited higher current efficiency (up to 96%) for H2O2 generation with a significant production rate. This experimental result, along with the results from chapter two, suggests that graphitic nitrogen moieties are responsible for two-electron ORR to hydrogen peroxide. In contrast, pyridinicand pyrrolic- nitrogen moieties are responsible for four-electron ORR to water. The ability to selectively dope different nitrogen moieties is unique to this GUITAR material. This investigation, along with the resistance behavior of the N-GUITAR electrode, is summarized in chapter five. Chapter five further reveals the possibilities of this material as an excellent electrocatalyst and robust electrochemical sensor for numerous applications.doctoral, Ph.D., Chemistry -- University of Idaho - College of Graduate Studies, 2021-1
Microbial Community Dynamics and Function During Coarse Woody Debris and Leaf Litter Decomposition
No full textNitrogen fertilization is a common soil amendment; however little is known about how surface and belowground wood decomposition are affected by N amendments. We analyzed data from a field study in Norrliden, Sweden where the mass loss of trembling aspen (Populus tremuloides Michx.) and loblolly pine (Pinus taeda L.) wood stakes was recorded for three years. Wood stakes were placed horizontally on the surface of the organic horizon and at the interface between the mineral and organic horizons and inserted vertically into the mineral soil in plots treated with different amounts of ammonium nitrate fertilizer (no nitrogen (control), 60 kg ha-1 (N1), 120 kg ha-1(N2)). Fungi colonizing the wood stakes were also analyzed. Mass loss was greater in the mineral soil for aspen and pine stakes compared to surface stakes and N treatment only affected stakes placed on the surface. Nitrogen treatment did not affect fungal richness, but it did affect fungal community composition. Overall, N treatment had minimal effect on coarse woody debris (CWD) decomposition and CWD decomposition appeared to be driven more by microclimatic conditions of the soil as related to soil depth. Microbial communities are important drivers of decomposition and the ability to link community structure to function will strengthen our understanding of their role in C and nutrient cycling. We used microcosms to study how seven different microbial communities sourced from areas with different vegetative cover decomposed the same litter by recording mass loss, respiration, and total volatile organic compound (VOC) production weekly for 12 weeks. We sampled microbial community composition at four time periods during the 12-week study. Mass loss was more related to fungal community as a whole while respiration and total VOCs were more related to the fungal class Sorardiomycetes. Microbial communities remained compositionally distinct throughout the study and were related to differences in decomposition, respiration, and total VOC production, suggesting that microbial communities are not functionally redundant. Because of the differences observed in total VOCs and community composition, we propose that microbial community structure could be studied via VOC production.masters, M.S., Environmental Science -- University of Idaho - College of Graduate Studies, 2021-1
Assessment of Various Mitigation Strategies of Alkali-Silica Reactions in Concrete and Implementing the Outlier Detection Method in Industrial Applications
No full textThe mitigation of Alkali-Silica Reaction (ASR) has become more urgent than ever before, due to the high demand for concrete in an increasingly industrialized world with expanding urban infrastructure. This study analyzes the efficacy of additives in cement aggregate mixtures in stopping or mitigating the Alkali-Silica Reactions that damage the structural integrity of concrete construction. While there is existing research on certain supplementary cementitious materials or SCMs and their role in stopping ASR in concrete, in this research we analyze the effectiveness of Metakaolin, waste glass powder, basalt fiber, and lithium in preventing ASR using the latest and most reliable test methods available. We utilize the ASTM C1260 14-day accelerated mortar bar test for this purpose, and all supplementary materials are tested separately according to ASTM standards. Moreover, concrete properties such as compressive strength, and concrete flow test are also evaluated in order to complement the test results. Our preliminary findings are that Metakaolin when used as a SCM at a ratio higher than 10% (per cement replacement), effectively mitigates ASR in the concrete prisms used for testing. Additionally, it was found that Metakaolin also keeps concrete expansion under the safe level of 0.10%. The test results of the other two SCMs glass powder and basalt fibers showed insignificant mitigation of ASR in concrete. Furthermore, although expansion was slowed, it was not kept under safe levels (0.10% expansion) of the test. Finally, the experimental results point positively to the simultaneous addition of multiple SCMs and additives in cement mixtures to further increase its numerous properties. The rapid development in construction industry induces a large amount of concrete data that are usually measured and analyzed everyday naming that concrete is the second usable material on earth. Concrete is made from numerous ingredients that have huge variability either at the design stage or at the testing stage. The main goal of this paper is to quantify the anomalies and outliers during the design phase of concrete mixtures. Concrete mixtures have various percentages of ingredients such as cement, slag, fly ash, water, superplasticizer, and fine and coarse aggregates. Machine learning and data mining is considered a very thriving topic in many research fields and its implementation in the construction industry still limited. Concrete community is in need for such a tool to produce efficiently designed concrete mixtures. Outliers could occur during the evaluation of samples’ measurements that might include human or system errors. The Local Outlier Factor (LOF) algorithm is the most common method used to determine outliers, however, the LOF has some challenges. In this paper, an anomaly-based outlier detection algorithm called Isolation Forest based on a Sliding window for the Local Outlier Factor (IFS-LOF) algorithm, is proposed to solve the limitations of the LOF in evaluating 1030 concrete mixtures. The proposed algorithm works without any previous knowledge of data distribution and executes the process within limited memory and with minimal computational effort. The evaluation of results proved that the IFS-LOF algorithm is more efficient in detecting the sequence of outliers and provided more efficient accuracy than other state of the art LOF algorithms.doctoral, Ph.D., Civil Engineering -- University of Idaho - College of Graduate Studies, 2021-0
Model-Based Learning to Augment Collaborative Filtering: Prediction and Evaluation
No full textCollaborative filtering (CF) is a novel statistical technique developed to retrieve useful information and to generate predictions based on provided data from users. It is fundamentally characterized by recommender systems (RSs), which have recently gained and attracted researchers’ attention. CF can be defined as systems and software tools that automatically and effectively generate a list of recommendations of the most suitable items to a target user by predicting a user’s future ratings for unseen items. As a field of study, the dramatic evolution of machine learning solves problems that appear in the early time of CF systems. Researchers claim that the main research focus of current CF research, especially in the big data era, is how to effectively develop models to address the problems of data sparsity and limited coverage that CF systems unexpectedly experience. The particular objectives of this empirical research are: (1) providing a novel model based on machine learning and data mining algorithms that address the data sparsity problem in CF, (2) providing a novel similarity model based on rating alignment that results in better accuracy of rating prediction compared to the other similarity models used for CF, (3) providing a novel model to incorporate information from social network sites (SNSs) in order to augment CF and solve the data sparsity problem, and (4) providing academic advisory RS based on a web-based framework. To validate the effectiveness of the proposed models, intensive experiments are conducted to compare the performance of the proposed models with the state-of-the-art CF models using four datasets collected from four popular RSs’ domains (music, jokes, books, and movies). These proposed models are computationally efficient and effectively generalized to other related fields in RSs. Results retained from evaluation metrics reveal that the proposed models can demonstrate promising prediction accuracy and improve the prediction performance than the state-of-the-art algorithms. Furthermore, the proposed models can successfully address the data sparsity and the limited coverage problems.doctoral, Ph.D., Computer Science -- University of Idaho - College of Graduate Studies, 2021-0
Exploring mechanical and biochemical regulators of the collagen crosslinking enzyme, lysyl oxidase, in tenogenically differentiating Stem cells
No full textCollagen crosslinking impacts normal tendon mechanics. This thesis first reviews the major types of collagen crosslinks found in tendon (enzymatic crosslinking and non-enzymatic), and their contributions to tendon mechanical properties, as well as their mechanisms of formation. Enzymatic crosslinking that occurs during normal development is mediated by the enzyme lysyl oxidase (LOX), which plays a role in collagen matrix stiffening and strain attenuation in tendon mechanical loading. However, the cellular mechanisms regulating LOX production remain largely unknown. Several possible regulators of LOX have been identified, and experiments were conducted to, explore transforming growth factor (TGF)β2, hypoxia-inducible factor (HIF)-1α, and mechanical stimuli through applied shear stress as potential LOX regulators in mesenchymal stem cells (MSCs). TGFβ2 significantly upregulated both LOX and HIF-1α in MSCs, suggesting that, in addition to inducing tenogenesis, TGFβ2 may play a role in regulation of enzymatic crosslinking. Although hypoxic environments have been shown to upregulate LOX, HIF-1α, a transcription factor that occurs in hypoxia, does not have any significant effects on LOX, although it is upregulated in early TGFβ2-induced tenogenesis. Shear stress applied at 25 mPa did not impact LOX production, although it may be explained by magnitude-dependent regulation. A different level of mechanical stimuli, perhaps one that imitates loading experienced physiologically, could induce LOX, as seen in previous studies using different levels of stress. Other types of collagen crosslinking that occur include nonenzymatic crosslinking, or advanced glycation endproducts (AGEs) and might also be worth exploring in future studies. Due to the slow turnover of collagen, free glucose reacts to form collagen crosslinks between amino acids in the collagen fibrils. This occurs over time during the aging process, but much more quickly in hyperglycemic environments like those seen in diabetes. AGEs typically contribute to tissue stiffening and can be detrimental to tissue healing. Overall, collagen crosslinking is critical for tendon formation and homeostasis. Our results suggest that TGFβ2 may play a role in regulating enzymatic crosslinking by MSCs, and these findings could be used in future studies to improve tendon mechanical properties and advance regenerative medicine.masters, M.S., Biological & Agricultural Engineering -- University of Idaho - College of Graduate Studies, 2021-0