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A Retrofit Analysis of Unreinforced Masonry Walls Under Blast Loading
No full textThe primary objective of this study is to find effective ways of retrofitting unreinforced concrete masonry units (CMU) walls to survive against harmful blast loading effects. The retrofit investigation considered the use of carbon fiber reinforced polymers (CFRP), Kevlar, aluminum, and steel applied to CMU and exposed to a 100-kg ANFO charge at a 15-meter standoff distance. For the experimentation, Ansys Workbench and Ansys Autodyn (finite element software) were used to model a control CMU wall and compare model simulations with the retrofit materials at varying thicknesses. The control CMU wall measured 1000 millimeters long, 2200 millimeters tall, and 200 millimeters thick. Each material was added to the control wall in 3.175-mm increments starting with 3.175 millimeters and ending with 19.05 millimeters.The study concluded that each material made a significant contribution to decreasing the wall’s overall deflection values when compared to the control. After the data collection process, a discussion was held to compare the overall percent improvement, material weight, material costs, workability, and constructability for each material selection. With all factors considered, the discussion concluded that the use of a fiber reinforced polymer would be the best retrofit option. Keywords: Unreinforced masonry, blast loading, finite element, carbon fiber reinforced polymer, Kevlar, aluminum, steelmasters, M.Engr., Civil Engineering -- University of Idaho - College of Graduate Studies, 2020-1
Preferences for Alternative Water Supplies in the Pacific Northwest: A Choice Experiment
No full textUnderstanding residential water preferences allows utility and municipal wa- ter managers to improve residents’ welfare through informed pricing and investment decisions. This paper employs a choice experiment (CE) to elicit residents’ stated preferences for water sources, storage methods, and conservation policies across the inland Pacific Northwest. Generally, results suggest that–conditional on needing an additional municipal water supply–individuals have a strong aversion to creek-water, and are relatively indifferent to reclaimed wastewater or additional diversions from large rivers. Residents also have a strong preference for additional local water storage, either in the form of aquifer injection or reservoirs. CE results also suggest strong heterogeneity in preferences correlated with gender, current water supplier (municipal or personal well), and where respondents grew up. In particular, males are signifi- cantly more price-driven than females, and well-owners have a strong preference for municipal water reclamation.masters, M.S., Agricultural Economics and Rural Sociology (Applied Economics) -- University of Idaho - College of Graduate Studies, 2020-0
Crystallinity and Albedo: In-situ VNIR Analysis of Glassy lava flow Surfaces at Jordan Craters, OR
No full textWe present an in-situ analysis of the albedo of Visible Near Infrared (VNIR) and the petrologic texture of the surface of a glassy lava flow at Jordan Craters, OR. 10 of our collected samples, from the surface and vent of our flow, had very low reflectance in the VNIR range 0.02 – 0.04 and textures of mostly glass and phenocrysts of olivine and plagioclase. These dark samples were rapidly quenched morphologies, like spatter and scoria. Samples that had brighter VNIR (33% of samples) and had defined absorption bands at 500nm, 1500nm, 1900nm, and 2100nm also had devitrification, alteration, or higher crystal content, and were collected along the margins of the flow. Alteration was identified through the presence of specific absorption bands, e.g. 1900nm, while devitrification and higher crystal content were differentiated based on the depth of the absorption bands, with higher crystal content having the more well-defined absorption bands. We attribute these variations, alteration and devitrification, to the presence of water both during emplacement and post-cooling. A ~0.03 change in albedo that correlated to a range of 28% to 81% glass content across the flow was most clear from the in-situ measurements but was also broadly detectable from satellite ASTER data. Our findings indicate that VNIR can be used to identify variations in petrologic texture across glassy basaltic lava flows. In settings where in-situ study is not possible, such as on Mars, satellite data may give insight to where quenched basalts occur. This has implications for estimating the distribution of ancient water or ice on Mars and will allow for the better identification of locations for in-situ study by rovers for looking for evidence of ancient life.masters, M.S., Geology -- University of Idaho - College of Graduate Studies, 2020-0
The Utilization of Silica Nanosprings as an Insulating Support to Characterize the Morphology, Electrical Transport, and Optoelectronic Properties of Two-Dimensional Nanocoatings
No full textThis dissertation explores the nucleation, evolution, and growth dynamics of silica nanosprings and the utilization of silica nanosprings as an insulating support to characterize the morphology, electrical transport, and optoelectronic properties of two-dimensional nanocoatings. The primary results of this research are threefold. First, we identify the mechanisms of initial formation and growth dynamics of silica nanosprings. Second, we coat the surface of silica nanosprings with a novel conductive carbon to create a core–shell structure and definitively identify that the conductive carbon is a nanocrystalline graphitic layer consisting of an agglomeration of carbon nanospheres formed by the accretion of graphitic flakes. Third, we observe the photoconductive behavior of a single ZnO-coated silica nanospring, present models to explain the photoconduction and recombination mechanisms responsible for the observed sub-bandgap photocurrent rise and decay behavior, and present a phenomenological model to describe the characteristics of the saturation photocurrent dependence on excitation intensity. A single silica nanospring is composed of multiple individual amorphous silica nanowires bound together via a common catalyst to form a larger, well-defined helical structure with a wire diameter of ~70–500 nm, an outer diameter of ~200–1000 nm, and lengths on the order of hundreds of microns. Until now, the initial phases of formation and growth dynamics of this type of silica nanospring had not been explored. We find that the low-temperature growth conditions facilitate the formation of an asymmetrically-shaped gold catalyst. A row of silica nanowires is formed in an energetically favorable process beneath the gold catalyst. The varying growth rates of the individual nanowires produce an asymmetry in the interfacial surface tension and a corresponding variable work of adhesion along the outer boundary of the catalyst–nanowires interface. The variable work of adhesion provides the asymmetry necessary for the catalyst’s helical precession, which subsequently produces the silica nanospring’s helical morphology. The surface of silica nanosprings can be coated with an assortment of conducting and semiconducting materials to create a multifunctional nanomaterial that can be utilized in a wide variety of applications. One of these conducting materials, referred to as graphite from the University of Idaho thermolyzed asphalt reaction (GUITAR), has been coated onto silica nanosprings, and its structural and electrical properties have been investigated. Using a silica nanospring as a platform for GUITAR has allowed, for the first time, transmission electron microscopy images of a GUITAR coating that fully reveal its morphology. Images of a GUITAR coating obtained from scanning electron microscopy, transmission electron microscopy, and atomic force microscopy, together indicate that a GUITAR coating on a silica nanospring is a ~100 nm thick layer composed of an agglomeration of carbon hemispheres ~50–100 nm in diameter formed by the accretion of graphitic flakes ~1–5 nm in diameter. A Raman spectroscopic analysis of GUITAR and the measurements of the electrical resistivity and temperature coefficient of resistivity of 11 single GUITAR-coated silica nanospring electrical devices indicate that GUITAR is a form of nanocrystalline graphite. Polycrystalline ZnO was coated onto silica nanosprings using atomic layer deposition, and an electrical device consisting of a single ZnO-coated silica nanospring was fabricated and used to investigate the optoelectronic properties of the ZnO layer using near-ultraviolet (405 nm) and sub-bandgap (532 and 633 nm) excitation. The photocurrent responses of all three excitation sources display a typical two-step fast and slow rise and decay response. Physical models are presented and propose that the photocurrent rise and decay characteristics depend on the excitation energy and the trapping of electrons and holes in intermediate defect levels within the bandgap. A phenomenological model is presented to explain the breaks in the slopes of the saturation photocurrent versus excitation intensity profile for each excitation source. We find that these slopes are a function of the transition probabilities of defect states, the number of carriers available to populate the conduction (valence) band, and the rate at which electrons and holes recombine.doctoral, Ph.D., Physics -- University of Idaho - College of Graduate Studies, 2020-1
Detection of Cyber Bullying Using Social Media Network Data
No full textThe rapid development of online communication and information sharing platforms and the enthusiastic participation of their users have enabled peer-to-peer communication at unprecedented scale and diversity. On one hand, this communication channels, such as online social networks and news sharing websites, offer myriad opportunities for knowledge sharing and opinion mobilization. On the other hand, they also serve as a fertile domain for an abundance of unfortunate intimidation and hateful aggression and cyberbullying towards individuals targeted because of their identities or expressed opinions. In this thesis we have proposed an ensemble approach towards the detection of cyberbullying using machine learning techniques.doctoral, Ph.D., Computer Science -- University of Idaho - College of Graduate Studies, 2020-0
Connecting the Puzzle Pieces: Adapting Virtual Reality Environments with Biometric Data to Support Learners with Autism Spectrum Disorder
No full textEducators face many challenges when promoting engagement and retaining attention in neuro-diverse learners, such as those with autism. Recent advancements in virtual reality technology, biometric scanning, and education epistemology are opening new opportunities for these educators to connect with their students through adaptive real-time education simulations. This paper reviews the viability of several elements to propose a new, innovative framework for educating neuro-diverse individuals. First, virtual reality provides an immersive, controlled, high-fidelity presentation platform. Second, biometric data from cardiovascular responses, electrodermal activity, electroencephalograph, and eye tracking provide the data to determine mental state and adapt the environment. Finally, exploratory based learning grounds the learning experience helping engage learners and presenting knowledge in context. Together, these disparate elements have the potential to form a cohesive system, empowering neuro-diverse educators while promoting student success.masters, M.S., Architecture -- University of Idaho - College of Graduate Studies, 2020-0
""To Make a Pure Resort"": The Conflict Between Temperance and Profit at the Saltair Resort Under the Church of Jesus Christ of Latter-Day Saints
No full textIn 1893 Saltair, a resort with a massive Moorish revival pavilion, was built on the shores of the Great Salt Lake and attracted visitors from across the state of Utah. Owned by the Church of Jesus Christ of Latter-Day Saints, which was heavily influenced by the temperance movement, the question of whether alcohol should be served was a controversial subject by the owners and visitors alike. The Church wanted a wholesome resort where families could relax in peace away from alcoholic influences yet were also concerned that banning alcohol would result in the loss of prots. Despite this controversy and the hesitancy of the Mormon owners to sell alcohol, evidence of alcohol consumption is prevalent in the archaeological record. Here, I examine the role of alcohol at Saltair, and the spaces in which it was consumed. Additionally, I consider the attitudes that patrons and owners of Saltair had towards alcohol, and how its presence impacted their experience at the resort.masters, M.A., Anthropology -- University of Idaho - College of Graduate Studies, 2020-0
Development and Evaluation of a Data Acquisition Camera Technique to Measure Opening Loads Caused by Plasticity-Induced Crack Closure during Fatigue Crack Growth
No full textThis document describes the experimental approach used to identify crack-tip opening loads due to the plasticity-induced crack closure under fatigue loading conditions using a data acquisition camera (DAC) and DaVis, an advanced data analysis software. The primary pieces of equipment used in the experimental work are as follows: (1) a loading frame, which uses hydraulics to supply and control a cycling load applied to a compact tension (CT) specimen, (2) the DAC itself, set up on a stable tripod to collect the images required for specimen analysis by this method, and (3) a computer equipped with the DaVis software, used to analyze and process the images collected by the DAC. The DAC was used to collect images of the crack closing and opening during fatigue loading. The goal was to determine the exact instant of crack-tip opening during loading and unloading. Images were collected in series for each applied cycle, with separate data sets collected for the loading and unloading portion of each cycle. Data was collected at three ΔK levels, i.e., 10, 15, and 20 MPa∙√m, to identify changes in opening load as the crack increased in length. Using the DaVis software, the images collected were used to compute crack opening displacements, from which it could be determined whether or not the crack was open or closed at a given point in the cycle. As expected, the data collected indicated that opening load changes with increasing ΔK value. The computed opening load values were consistent with those computed using other methods, as will be laid out in this paper.masters, M.S., Mechanical Engineering -- University of Idaho - College of Graduate Studies, 2020-0
Tool Selection for use in Water Quality Based Citizen Science Projects
No full textWhen citizen scientists conduct water quality monitoring, the results can include better educated communities, increased local political participation, and an increased breadth in the geospatial and temporal range of the sampling campaigns. Unfortunately, the value of data collected by citizen scientists is often criticized as being inaccurate and unreliable. To address these criticisms, it is necessary to quantify volunteer accuracy using different tools and data collection strategies. The first chapter of this thesis reviews current citizen science literature and introduces the following two chapters, which focus on tool selection for citizen science monitoring. In the second chapter of this thesis evaluates the capacity of citizen scientists to gather accurate nitrate data. Specifically, this research focused on the quantification of Hach © nitrate test strips, which volunteers analyzed visually or using a cell phone app. The objective of this work was to compare the accuracy of the two quantification methods. The objective of the final chapter is to review the literature and identify the potential for citizen science research methods to contribute to environmental monitoring efforts through the collection of biologic tissues.masters, M.S., Water Resources -- University of Idaho - College of Graduate Studies, 2020-0
Community Learning in Social Resilience
No full textMy project explores a new model with which to articulate increased social resiliency from community learning. The research question at hand is: what contribution does community learning as an outcome of nonformal community-based education, play in social resilience? This work builds on existing frameworks of group learning and of social capitals, to articulate community learning resulting in greater community adaptive capacity. Communities must assemble knowledge from multiple sources, along with local (place-based) cultural adaptations, to adapt to change (Armitage, et al., 2011). The research described in this dissertation includes four published or publishable chapters: • Introductory and Literature Synthesis • Extension Professional’s involvement in multistakeholder groups as an alternative to the usual “focus group” method of identifying community needs • Analysis of Volunteer Activity in Two University Extension Citizen Science Water Quality Monitoring Programs • Synthesis of observed effects on community learning from involvement in extension programming, multistakeholder groups, and volunteerism: developing and pilot testing for validity, a conceptual model (framework) as an Extension tool.doctoral, Ph.D., Natural Resources -- University of Idaho - College of Graduate Studies, 2020-0