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Modeling the historic distribution of bluntface shiner (Cyprinella camura) and estimating contemporary detection and occupancy probabilities in their historic range within Oklahoma
Get PDFBluntface Shiner (Cyprinella camura; BFS) is a fish that is endemic to the Arkansas, Lower- Mississippi, and Tennessee river basins, but exists as disjunct populations east and west of the Lower Mississippi River. Evidence suggests that BFS are experiencing declines across their known range, however the drivers of their decline are mostly unknown and knowledge of life history and habitat requirements of BFS remains limited. We aimed to address these knowledge gaps using species distribution modeling (SDM) and detection and occupancy modeling techniques. In chapter 1, we used SDMs to estimate the historic distribution of BFS across the entirety of its range, identify landscape scale factors which underly their distribution, and compare environmental conditions between the disjunct ranges. Our results revealed a naturally fragmented distribution in either BFS range, and that populations to the east of the Lower-Mississippi occupy streams with broadscale environmental conditions which differ from those to the west. In chapter 2, we focused on the historic distribution of BFS within Oklahoma, and we used a single season occupancy modeling framework while accounting for imperfect detection to estimate contemporary detection and occupancy probabilities for BFS. Our aims were to identify best gears (seine versus backpack electrofishing) for detecting BFS and the environmental conditions which influence gear effectiveness, as well as environmental factors which influence occupancy of the species in wadable streams of their historic range in Oklahoma. We found that detection of BFS varied with gear type depending on environmental conditions present at our sites, but seine produced overall higher detection probabilities. Our occupancy estimates were low despite our search within the historic distribution within Oklahoma. This suggests that BFS are rare and have seemingly declined across large portions of its range. Our findings call for focused conservation and management efforts for BFS across their entire range
Magic Lantern Tales: A Music/Text Analysis of the Vocal Works of Cheryl-Frances-Hoad
Get PDFThis document explores Cheryl Frances-Hoad’s song cycle Magic Lantern Tales, as a highlight of her oeuvre as well as of contemporary art song. Each song in the cycle, and a select few of Frances-Hoad’s other vocal works, will be studied from a performer’s perspective to identify Frances-Hoad’s compositional approach to song, as well as her individual style in Magic Lantern Tales. The document examines stylistic features and unifying elements of Frances-Hoad’s vocal repertoire, with particular emphasis on music/text relationships. This document is motivated by a desire to raise awareness of Frances-Hoad’s vocal literature. Serving as an introduction to Frances-Hoad and her vocal music, this document offers a biography of the composer and a music/text analysis of some of her vocal works, specifically Magic Lantern Tales. For each of her songs examined, background, compositional style, and text setting will be considered. A study of each of these elements, combined and in conjunction with the context of the poetry, will reveal Frances-Hoad’s approach to portraying a story, especially through text painting. It will also explore the role this particular cycle plays as a historical commemoration of World War I. As the proverbial saying goes, “Tell me and I forget, teach me and I may remember, involve me and I learn.” Music not only involves, but has the power to move and change us. The commemorative nature of this song cycle in accordance with compositional and performance devices that carry the power of the words, and ultimately the stories, to the hearts of the listener, can create an experience of remembrance that ensures historical preservation through music. Ultimately my intention is to demonstrate the significance of Magic Lantern Tales to the genre of modern art song, and perhaps more importantly, to demonstrate Cheryl Frances-Hoad’s merit as a living song composer. In addition, this study of Frances-Hoad’s compositional style and approach to storytelling will hopefully bring a wider awareness of her vocal music as a whole, and will promote more frequent performances of this music among students and professionals alike
Generative Design, Characterization, and Testing for Additive Manufacturing of Lightweight Structures
Get PDFGenerative design has developed over the years through various CAD software’s and has changed the industry in new ways. Generative design has opened a new aspect of engineering that can change industries through design created with artificial intelligence technology. Through generative design, various components and characteristics of materials and objects can be reinvented to make them lighter weight and more cost effective within the industry. Within this thesis, the aspects of Fusion 360, a CAD software, has been reviewed and utilized when creating an I beam. The I beam has ran through various simulations to understand the forces and constraints applied on it to see the force the beam will break at. The safety factor allows for the understanding of when the beam will break and how the force can be withstood with a new design. With the known forces, the beam was placed in the generative design component of the software to redesign the beam based on the given information and requirements. The generative design portion of the software and artificial intelligence created a new object via iterations to be evaluated. Through additive manufacturing the beam was printed with PLA and resin materials. This thesis discusses the processes of 3D printing and testing of the I beam and generative designed I beam. Through testing, the analysis of the displacement, mass, and force of the I beams was evaluated with the Fusion 360 results to see if the requirements was met during the redesign
Design and development of a Selective Laser Sintering (SLS) 3D printer for potential biomedical engineering applications.
Get PDFAn additive manufacturing method called Selective Laser Sintering (SLS) involves heating material particles to bond them together. Each two-dimensional layer is selectively sintered in the fabrication piston until the part is entirely manufactured. New layers are created by depositing material from the delivery piston to the fabrication piston, where the laser will follow the cross-sectional toolpath generated from a slicer. One of the most significant advantages of SLS 3D printing is that there is no need to have structural support for the material. The unused material provides support for the sintered shape throughout the whole process. Due to its biocompatibility and mechanical properties, sugar can be a biodegradable structure with many applications in biomedical engineering, such as sugar skeletons for tissue engineering and drug delivery [1]. Thus, this thesis examines the SLS process to print simple and complex geometry single-layer sugar samples. Each sample is designed to showcase the sintering capabilities and technology of an SLS 3D printer for potential biomedical engineering applications. Each sample is sliced into its cross-sectional layers using a non-proprietary software called Slic3r; its G-Code is translated to generate the lasers toolpath, then uploaded to the printer. The printing parameters such as heat chamber temperature, laser scanning speed, and laser intensity are the major determining factors in sample accuracy. Therefore, ideal printing parameters are discussed, and samples are evaluated through various tests. Results show that this printer can sinter single-layer sugar samples in multiple geometries to an acceptable level of accuracy. The printer is limited to two-dimensional printing. However, the results of the final samples indicate that this printer will be able to print in three dimensions in future research
Techno-optimization of CO2 transport networks with constrained pipeline parameters
Get PDFIn planning large scale carbon sequestration projects, one of the key parameters affecting project economics is the selection of optimal pipeline transportation networks connecting physical locations of carbon sources to sinks (or injection sites). This network is usually determined based on several limiting factors including existing right-of-way, densely populated regions, topology, etc. Open-source tools such as SimCCS2.0 do an effective job in proposing provably optimal routes for construction of new pipelines but are unable to accommodate existing pipelines in techno-economic optimization. With the newly amended 45Q laws offering 70% more tax credits for carbon sequestration than it did in the 2018 amendment, energy companies are looking more into repurposing gas and liquid transportation lines for CO2 transportation to abandoned oil and gas wells for carbon storage and this has further bolstered the need to have a method to account for existing pipelines in sequestration economics.
This project demonstrates a method to account for existing pipelines by 1 introducing zero cost paths into the cost surface to represent pipelines, 2 allowing for tie points into the existing pipeline by use of cost exclusion zones around zero cost paths and then, 3 calculating least cost paths and defining transshipment nodes along pipeline intersections. Doing this allowed for a reformulation of the alternate network paths between sources and sinks, and the network was then solved as Minimum-Cost-Network-Flow-Problem (MCNFP) modeled as a mixed integer programming problem.
The solution was developed using Python programming language and demo test cases are shown to illustrate the effectiveness of the solution in assessing cost reduction associated with CO2 transfer from sources tied into locations along existing transport pipelines to sinks.
This solution has been packaged into a software name Sequestrix and has been made publicly available on GitHub for researchers and economic analysts to take advantage of for evaluating large scale CCUS projects, and to encourage further development and collaboration
Magnetostratigraphic constraints of the pre Colorado-River integration Bouse Formation, Blythe Basin, Arizona
Get PDFMagnetostratigraphic studies offer unique insights into the orientation of Earth’s ancient magnetic field and provide an opportunity to determine the chronology of depositional events, particularly when combined with other dating methods. A successive series of basins trending south from Needles, California to Cibola, Arizona, records the evolution of the lower Colorado River through the preservation of sediments within the Bouse Formation. The Bouse Formation is characterized by basal marl, tufa, alternating silts and muds and Colorado River sands. It was deposited between ~5.24 and ~4.6Mya and represents pre-Colorado River integration deposits. Magnetic polarities are recorded in sediments during deposition and are revealed through the stepwise, destructive process known as alternating field (AF) demagnetization. The magneto-stratigraphic record near the end of the deposition of the Bouse Formation is poorly constrained trained and can be improved through the identification of a transition between the normal polarity Sidjufall (4.81-4.89Mya) and Nunivak (4.49-4.63Mya) subchrons. This study is anchored by dates acquired through tephrachronology of 40Ar/39Ar in detrital sanidine grains in the middle of the Sidjufall and Thvera subchrons. Sanidine grain analysis within Hart Mine Wash revealed an age of ~4.72Mya, corresponding to the age of the Lawlor Tuff, within the Bouse formation. Additional tephrachronology of the Bouse Formation revealed an age of 5.24Mya for the Wolverine Creek Tuff, just below the base of the Bouse Formation in the Lost Cabin Beds in Cottonwood Valley. The magnetic inclinations of the samples were anchored by the absolute ash dates and compared to the geomagnetic polarity timescale (GPTS) to determine the timing of deposition of the Bouse, and therefore the timing of arrival of the Colorado River to Blythe Basin. Surrounding the Hart Mine Wash ash lie sections of both normal and reversed polarity. Additional normal polarity intervals were captured in sediments surrounding Parker, AZ (Riversides) and further North near Lake Havasu City, within Mohave Valley (See Figure 2). The study consists of 3 unique locations, 26 individual sites, 40 sediment core specimens and 76 oriented specimens. Rock magnetic tests include hysteresis, first-order reversal curve (FORC) diagrams and Curie temperature analysis of thermomagnetic curves. These tests yielded low-quality results due to a low abundance of magnetic minerals, although the presence of stable ancient magnetization in specimens has been established through AF demagnetization. The results of this magnetostratigraphic study will improve the understanding of the timing of deposition of the Bouse Formation and date the arrival of the Colorado River within Blythe Basin to ~4.6-4.7Mya
Exploring CopterSonde Use for National Weather Service Operations
Get PDFThe CopterSonde is a state of the art sampling platform that can be used to advance the field of meteorology in operational forecasting and data collection. One capability of the CopterSonde is that it can collect high-resolution observations in the lowest levels of the atmosphere, including in the atmospheric boundary layer, which traditionally is not well sampled. CopterSonde data were collected during a mixed-phase precipitation event in central Oklahoma in February 2019 and during a quasi-linear convective system event in the Mississippi Delta in March 2022. The primary goal of this study was to determine the operational benefits of CopterSonde data when used by National Weather Service forecasters. Specifically, a virtual post-event forecast experiment investigated the impacts on forecasters’ operational processes, decisions, and communication of hazards.
Volunteers from four National Weather Service Weather Forecast Offices in the Southern Region initially participated in a background survey during the winter of 2021. This survey investigated the current suite of boundary layer observations available and introduced the CopterSonde platform to them. The survey results suggested that the most anticipated benefits from incorporating CopterSonde data in NWS operational forecasting were: improved understanding of numerous weather phenomena (severe and winter weather were highlighted), increased forecaster confidence and situational awareness, and enhanced communication of hazard expectations to core partners and the public. These findings guided the goals and creation of a forecast experiment that followed.
In the fall of 2022, 16 total forecasters from the 4 Weather Forecast Offices completed 2 case studies over the course of 4 days. The goals were to investigate the impact of the CopterSonde data focusing on their situational awareness, hazard identification, and communications. For each case, CopterSonde data were only provided to half of the forecasters, and focus groups were held at the end of each day. These meetings allowed forecasters to discuss the impacts of the CopterSonde data for both cases.
A situational awareness framework was used to guide the thematic coding of data collected during the case studies. Forecasters with the CopterSonde data reported greater levels of situational awareness and higher confidence in their environmental analysis and decisions. One key finding between the two cases was that the CopterSonde data had a demonstrably more significant impact on the winter weather case versus the severe weather case. This difference in impact is due to the greater uncertainty regarding expected outcomes for the winter weather case. When using the CopterSonde data to identify precipitation types, the probability of detection for forecasters, during the winter weather case, was 0.50. This exceeded that of the group without the CopterSonde data by 0.12. During the severe weather case, an outflow boundary and its impacts were identified in the CopterSonde data. This feature went unnoticed by participants that did not have CopterSonde data available. Overall, forecasters were very enthusiastic about the potential to include CopterSonde data in their day-to-day operations when making decisions and communicating expected weather impacts to their audiences
Relative Distances: Sailors and Women on the Philadelphia Waterfront, 1760-1825
No full textThis dissertation uses Philadelphia as a case study to reveal the varied and significant relationships—business, sexual and romantic, and familial—that connected Anglo-Atlantic sailors and women across land and sea between 1760 and 1825. Placing traditional social history sources such as city directories, maps, insolvency petitions, Alms House records, public-private aid society minutes, newspapers, and personal correspondence alongside analyses of maritime culture texts such as sailor songs, broadsides, periodicals, novels, plays, and prints, it reveals the motivations, close connections, and patterns of behavior that facilitated Philadelphia’s seafaring labor cycles. This research adds nuance to enduring portrayals of common seamen as footloose “Jack Tars” whose work separated them from land-based community and domestic life by choice or by fiat, and instead focuses on the everyday choices that sailors and women made to transcend physical distance and deliberately incorporate maritime labor cycles into their domestic, communal, and commercial lives. Connecting Atlantic history with histories of urban port cities, commerce, women and gender, and the family, this project also traces various changes over time, from the transformation of both sailors and working-class women into objects of moral intervention or nostalgic caricature to the transition between wooden and steam ships, the increased appearance of women as passengers and proxy crew on commercial and naval vessels, and shrinking legal and economic opportunities for women to act as femes soles in the absence of a male head of household. At the same time, it highlights key continuities, including the ubiquitous presence of women in and on the Philadelphia waterfront, interconnected oral performances and written transmissions of songs by and about sailors, and sustained patterns of cross-gender contact and connection in a diverse, dynamic, and expansive cityscape
Investigating Arctic Cyclone-Tropopause Polar Vortex Interactions with Observing System Simulation Experiments
Get PDFTropopause polar vortices (TPVs) are upper-level cyclonic circulations that are common in high latitudes. TPVs most directly impact weather at the surface by providing baroclinic forcing for the development of Arctic cyclones (ACs), surface low-pressure systems over the Arctic Ocean and surrounding landmasses. ACs, in turn, help to drive the Arctic heat and moisture budgets via transport from the midlatitudes and govern sea ice variability on short timescales via dynamic and thermodynamic influences. Although prior studies have demonstrated and examined the link between TPVs and ACs, the exact role played by the TPV and its characteristics in the development of the surface cyclone has yet to be established. In the present study, we seek to take a step forward toward closing this gap using an idealized observing system simulation experiment (OSSE). This approach involves simulating dense dropsondes over a TPV as a surface cyclone is forming and examining the changes that the additional observations produce to the TPV and resulting surface cyclone. The ECMWF Cubic Octahedral grid Nature Run (ECO1280) is taken as the truth for the OSSE (all observations are simulated from the output of this model), and the Model for Prediction Across Scales (MPAS) is coupled with the Data Assimilation Research Testbed's (DART) ensemble adjustment Kalman filter in order to run numerical experiments. It is expected that the development of the TPV and surface cyclone will be especially sensitive to moisture observations, which influence TPV strength via diabatic processes, and that proper representation of mesoscale dynamic features along the tropopause will be key to accurate forecasts.
In addition to a control in which only existing observations are simulated from ECO1280, we conduct four primary experiments assimilating additional dropsonde observations of (1) temperature, (2) humidity, (3) temperature and humidity, and (4) temperature and humidity over a broad region. All of the experiments reduce errors relative to the control throughout the atmosphere and at the surface, with Experiment 4 producing the most accurate forecast of the surface cyclone. The humidity observations lead to enhanced PV generation near the tropopause and, by the end of the forecast, a deeper surface cyclone. These improvements are more limited when temperature and humidity dropsondes are combined. Experiment 4 exhibits a much more accurate representation of the PV features surrounding the main TPV and other synoptic scale features surrounding the system (including a Rossby wave breaking into the Arctic from the midlatitudes), which may explain its better forecast performance with respect to the surface cyclone. Additionally, it is discovered that AC strength is linked to the accuracy of the modeled distance between the surface cyclone and the core of the TPV throughout its lifetime (an indicator of baroclinic growth potential). This TPV-AC distance is, in turn, controlled by a breaking midlatitude Rossby wave that was not directly observed in any of the experiments
What drives working adults to be lifelong learners? Determinants and patterns of adult education participation in the United States
Get PDFWith the recent shifts in the global economy, many scholars and policymakers are in broad agreement on the importance of lifelong learning practices in the occupational sphere. In response, there has been growing academic interest in adult education participation in which working adults acquire knowledge and skills to fulfill the ever-changing needs of the world of work. Many researchers have revealed that participating in adult education provides a wide array of benefits for individuals, organizations, and society. Yet, despite the increased research efforts, empirical findings are still inconclusive on what contextual factors most decisively or relatively importantly contribute to determining and patterning working adults’ participation in adult education. In this context, this study is conducted to present a holistic picture of adult education participation. To that end, the purpose of this study is to re-examine the determinants and patterns of adult education participation of working adults by leveraging emerging analytic techniques to capture population-level insights on (1) what drives participation in adult education and (2) how discrete patterns in adult education participation emerge.
The data is drawn from the 2017 U.S. Program for the International Assessment of Adult Competencies (PIAAC). The total sample size was 1,283 respondents aged 25 to 65 years old who had work experience in the last 12 months. Outcome measures were formal adult education and training (AET), non-formal AET, and informal learning, all of which indicate three major pillars of adult education participation. The selected 19 independent variables represent working adults’ individual-level (i.e., demographic information, human capital, and learning-related socio-psychological states) and work-related contexts. Through the random forest classifiers (RFCs) technique, one of the machine learning algorithms, this study identified important factors associated with participation in adult education. In addition, latent class analysis (LCA) was applied to investigate discrete patterns of adult education participation among sub-groups of working adults that share similar profiles of individual-level and work-related characteristics.
According to the results obtained from RFCs models, first, skills proficiency and/or utilization appeared to be the far most critical influencers across every type of adult education participation. Second, education level and monthly income were the common salient predictors across types of adult education participation. Third, predictors explaining adult education participation somewhat varied depending on the types of adult education. By applying the LCA approach, this study identified four latent classes of working adults in adult education participation: (1) low-participation learners, (2) high-participation learners, (3) informal learners, and (4) structured learners. Moreover, the results demonstrated that the broader separation of working adults’ participation in adult education itself was strongly affected by situational and institutional contexts, whereas individual preference or selection across types of adult education relies on personal demographics and human capital. Based on the findings, this study concluded with several discussions and implications for research, policy, and practice