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Software Engineering Methodologies in Developing a Railway Condition Monitoring System
Get PDFWith the continuous growth of rail track geometry irregularities due to aging, environmental factors, and wheel loads, rail track requires frequent maintenance. Railroads often rely on the precise and correct localization and identification of track irregularities that significantly destroy infrastructure and create life-threatening environments. Therefore, monitoring the conditions of the railroad tracks is vitally essential for ensuring safety, reliability, and cost-efficiency of operations. Consequently, agencies inspect all tracks twice a week per federal track safety regulations. However, their existing methods of track inspection are expensive, slow, require track closure, and pose a high risk to workers. The technical constraints of these methods impede network-wide scaling to all railroads. More frequent, continuous, and network-wide monitoring to detect and fix irregularities can help to reduce the risk of harm, fatalities, property damages, and possible financial losses.
This work introduces and develops a generalized, scalable, affordable inspection and monitoring system called Railway Autonomous Inspection Localization System (RAILS). In particular, the study aims to detect, locate, and characterize track-related issues. The research focuses on designing RAILS architecture, implementing data collection, and building algorithms that include inertial signal feature extraction, data processing, signal alignment, and signal filtering.
Case studies validate and characterize system accuracy by estimating the position of detected irregularities based on a linear referencing system. In one case study, the estimated position of the irregularity is compared with the actual position of ground truth data (GTA) observed by a railroad inspector. In another case study, a railroad inspector verifies the estimated position of the irregularity to demonstrate the system?s effectiveness and affordability for practical applications.
Therefore, railroad agencies employing the developed methods will benefit from reliable track and equipment conditions to make informed decisions that will lead to resource optimization. The conclusion of this research outlines the significant potential of the proposed system, including limitations and future work for practical, real-time, and autonomous implementation.
Proposed Nonparametric Tests for the Simple Tree Alternative for Location and Scale Testing in a Mixed Design
Get PDFSix nonparametric tests are proposed for the mixed design consisting of a randomized complete block design (RCBD) and a completely randomized design (CRD). The proposed tests are designed to test for differences in location and/or scale for a simple tree alternative. The tests are a combination of the Fligner-Wolfe test, modified Page?s test, and modified Ansari-Bradley test. A simulation study is conducted to determine how well the proposed tests maintain their significance levels. Powers of the six proposed tests are estimated under a variety of cases: changing the underlying distribution, changing the number of treatments, increasing the variance between the CRD and RCBD portion, changing the proportions of the number of blocks in the RCBD to the sample size for each treatment in the CRD, and changing the parameter arrangements. A recommendation for which test has higher power depends on whether the underlying distribution is symmetric or asymmetric
Regolith Based Polymer Matrix Composites for In-Situ Additive Manufacturing for Long Term Extraterrestrial Missions
Get PDFThe completed study investigated Martian regolith simulant composites? material properties when there was variation in the type of used Martian regolith simulant. Four types of Martian regolith simulant were mixed at varying weight percent loadings with polypropylene using twin screw extrusion. Test parts were made via injection molding with all the polymeric composites, and additive manufacturing with select polymeric composites. ASTM standard based tests and ANOVA tests were completed to investigate material characteristics. Depending on the creation process, the results suggested that Martian regolith simulant type impacted several material characteristics. During material processing, a foaming behavior was observed with all the materials, especially material that used MGS-1S. Additive manufactured parts were found to be impacted by the foaming behavior. A literature based thermal breakdown study suggested that thermal releases from the Martian regolith simulants were the likely candidates for the foaming behavior
?Only as Strong as We All Make It:? The Limitations of Fargo?s Civil Defense during the Early Cold War (1950-1964)
Get PDFIn this thesis, I argue that civil defense failed to take hold in the United States because it required local communities to take responsibility for protective measures. Fargo, North Dakota provides a case study for this analysis. The first section examines how Fargo adopted many practices from federal, state, and municipal civil defense organizations in the early 1950s, but struggled to implement them due to volunteer shortages. The second section explains how the hydrogen bomb forced officials to revise civil defense policies. It also details efforts by congressional and private bodies to increase federal responsibility for civil defense. The third section covers Fargo?s lack of response to the Berlin and Cuban Missile Crises, focusing on the unwillingness of Fargoans and their government to invest in civil defense. I conclude that today?s policymakers should recognize the limitations of making local communities responsible for policy implementation
The Impacts of Exotic Species on Native Bee Communities and Interactions in Novel Northern Great Plains Grasslands
Get PDFHuman alterations to landscapes impose novel conditions on native plant and animal species. Exotic plants are among these changes and are presently common and prevalent across Northern Great Plains (NGP) grasslands. Their introductions alter plant communities and influence the wildlife species that rely on the resources provided by plant communities. Exotic plants displace native plant species, but we do not understand how or if some exotic plants can provide resources to pollinating insects requiring floral resources. Considering the spread of exotic plants and the important ecological services bees provide, it is important to understand how native bees value and interact with exotic plants, and how exotic plants may shape bee communities in the NGP. To address this, we employ a unique dataset built from a statewide survey of bees and associated plant species across North Dakota grasslands to investigate the broad questions of how bees select between native and exotic floral resources, how exotic grasses may indirectly affect bee diversity through the plant community, and how exotic species dominance changes the interaction structure between bees and plants. From our selection analyses, we found native bumble bees selected for native plants and plant diversity over exotic plants whenever significant selection occurred, while European honey bees selected for exotic plants and floral resource density. However, both benefited from floral resource diversity, indicating that common management may exist for both groups. Invasive grasses did not affect bee richness at a broad scale but negatively influenced particular bees, such as ground-nesting species. We found litter accumulation to be influential over plant communities and particular types of bees based on their life history traits, indicating the need for grassland management practices that prevent homogenous plant structure. Finally, we found that exotic bees and plants influenced bee-plant interaction network properties through their dominance over contemporary pollination networks. This implicates that managing exotic species may be needed to reduce effects on the complex bee-plant interactions and consequent pollination services. Broadly, this work provides further evidence of exotic species effects on ecological communities and the first large-scale assessment of their impacts on bee communities in NGP grasslands
Characterization and Detection of Bacterial Pathogens of Common Bean
No full textCommon bacterial blight (CBB) (Xanthomonas axonopodis pv. phaseoli (Xap) and X. fuscans pv. fuscans (Xff), halo blight (Pseudomonas savastanoi pv. phaseolicola (Psp)), and bacterial brown spot (P. syringae pv. syringae (Pss)), are yield-limiting diseases of common bean in North Dakota and Minnesota. The objectives of this research were to optimize a multiplex quantitative PCR (qPCR) assay for rapid detection and quantification of four bacterial pathovars in common bean seed, leaf, and pod tissue; determine the aggressiveness of Xap and Xff isolates; and determine the race types of Psp isolates in North Dakota and Minnesota. A fourplex qPCR assay was optimized, and novel primers and probe were designed for pathovar-specific detection of Pss. Significant differences were observed in Xap/Xff aggressiveness across isolates evaluated and in susceptibility of the differential lines (P <.0001). The 60 Psp isolates were identified as Race 6, the predominant race in the region
Voting Technology, Democracy, and Propaganda: Ontological Considerations for the 2020 Presidential Election
Get PDFThe 2020 United States Presidential election was considered one of the most tumultuous political contests in the 21st century. During an international pandemic, travel restrictions and social distancing requirements created uncertainty about whether to vote in person or via absentee-mail-in ballot. The present study sought to investigate how voters experience different technologies in the 2020 United States Presidential election. Selected concepts in media ecology supplemented Fox and Alldred?s (2013) framework for new materialist inquiry to explore the technical material characteristics of voting technology and the discursive elements of voter fraud propaganda. By tracing the history of voting technologies and voter fraud propaganda, the analysis argued that the vast array of technologies and experiences of voting in the 2020 election rendered the idea of an archetypal or monolithic voting method insufficient. Therefore, the present study suggests an ontological revision for the ways we conceptualize the relationship between voters, voting technologies, and democracy writ large
Cornets, Creativity, and Celebration: The Life and Works of Virtuoso Cornetist Alessandro Liberati (1847-1927)
Get PDFAlessandro Liberati (1847?1927) lived during the late nineteenth and early twentieth centuries, when music for solo cornet was one of the most popular musical outlets in America. He and many performers of this instrument were virtuosos and traveled the world performing beautiful melodies and stylistic acrobatics on the instrument. They were the stars of their day and were often also conductors who led their own bands. Scholarly literature has only been written about a select few of these cornet soloists and band leaders. Names like Herbert L. Clarke (1867?1945), Jean Baptiste Arban (1825?1889), and John Phillip Sousa (1854?1932), are far more commonplace and receive more attention and performance. This leads to trumpet players playing their music and not the music of any of the other cornetists and band leaders of the past. Significant cornet music and band arrangements are overlooked, simply because trumpet teachers and performers do not know of the other cornetists and their music.
In this dissertation, I address the life and works of virtuoso cornetist Alessandro Liberati to bring forth new evidence that Liberati deserves greater attention as an important cornetist and band leader, a musician on par with his contemporaries. Liberati was an active soloist, band leader, and notable composer in Italy, Canada, and the United States. Liberati?s generous output of compositions for both solo cornet and band is compiled in the appendix of this study. I rely on biographies, encyclopedias, dictionaries, method books, historical band books, newspaper articles, scholarly articles, and historical recordings of Liberati from Gold Moulded Records (1902). In addition, I consulted Liberati?s musical scores and other archival documents housed in his collection at the Library of Congress. These sources show his wide influence as a cornetist, band leader, and composer. To this end, I suggest that Alessandro Liberati was just as successful as his contemporaries, well-liked by the public, sought after in his time, and deserves the same attention and performance today as his more well-known contemporaries
Synergistic Bioactive Enhancement of Phytochemical-Linked Food Safety Relevant and Health Protective Benefits of Select Plant-Based Foods and By-Products
Get PDFUnder-utilized, ethnic, or traditional plant-based foods, food ingredients, or processed plant by-products have dual functional food safety and health protective benefits due to their rich phytochemical profile. Pre- and post-harvest strategies can enhance the phytochemical content in plant-based foods and by-products with an improvement in the overall food safety and health protective benefits. Based on this rationale, the food safety relevant antimicrobial properties of amla, kokum, clove, garlic, grape, flaxseed, emmer wheat and corn distillers dried grain with solubles (DDGS) were selectively screened for in vitro antimicrobial activity against common food borne pathogens Salmonella, Listeria, Escherichia coli and one human gut pathogen Helicobacter pylori. Additionally, the health protective benefits such as antioxidant, anti-hyperglycemic, anti-hypertensive, and prebiotic activity were also investigated using in vitro assay models. Pre-harvest (ozone treatment) and post-harvest (milling, fermentation, extraction, synergy) strategies were also utilized to improve the phytochemical-linked functionality of these plant-based foods and plant by-product. Amla, kokum, clove, and garlic displayed high antimicrobial activity against most of the Salmonella, Listeria, and E. coli serovars tested, and the antimicrobial activity was specific for the bacterial strain. Integration of amla and kokum in grape juice further enhanced the antimicrobial, anti-hyperglycemic, and anti-hypertensive activity of the grape juice. Pre-harvest ozone treatment of white and red grape cultivars resulted in improved TSP content and anti-hyperglycemic relevant ?-amylase inhibitory activity. High phenolic-linked antioxidant activity was found in aqueous extracts of milled flaxseeds, while flax lignan had high anti-hypertensive property. Emmer wheat with hull had highest TSP content, antioxidant and antihyperglycemic activity (before and after milling) when compared to commercial wheat cultivars. Furthermore, extracts of Emmer fermented with lactic acid bacteria (LAB) showed an altered phenolic profile with mild antimicrobial activity against H. pylori. Extracts of corn DDGS fermented with LAB showed an altered phenolic profile and the antimicrobial activity against H. pylori was attributed a culture isolated from corn DDGS which was later identified as Bacillus amyloliquefaciens. These results indicate that screening and pre- or post-harvest processing strategies are an effective approach to improve the phytochemical-linked food safety and human health protective benefits of underutilized and common plant-based foods and plant by-product.
Multiscale Modeling of Conjugated Polymers Towards Predicting Their Multifunctional Behaviors
Get PDFEasy processability, tunable mechanical and optoelectronic properties, and the endless possibilities of molecular modifications enable conjugated polymers (CPs) to be used in a wide range of lightweight, low-cost, and flexible organic electronic devices. However, despite the tremendous efforts in molecular engineering and improved electronic properties, the thermomechanical-structure-property relationship of these semiconducting materials is still less investigated. Predicting the thermal, mechanical, and photovoltaics (PV) properties of CPs is challenging due to heterogeneous chain architectures and diverse chemical building blocks. To address this critical issue, this dissertation aims to employ novel multiscale modeling and data-driven approaches to characterize the thermomechanical and optoelectronic properties of CPs. In particular, we utilize machine learning (ML) and scale-bridging molecular modeling techniques scaled from quantum mechanics simulations to force field all atomistic molecular dynamics (AA-MD) and coarse-grained (CG)-MD simulations to explore the multifunctional behavior of CPs. Validated by experimental measurements, our AA-MD and CG-MD simulations can capture glass transition temperature (??), elastic modulus, and strain-induced deformation mechanism of the CPs with varied side-chain lengths and backbone moieties. Furthermore, through the integration of ML, AA-MD simulations, and experiments, we propose a simplified but accurate predictive framework to quantify ?? directly from the geometry of the CPs? repeat unit. Next, first-principle calculations developed upon density functional theory (DFT) are utilized to quantify electronic configuration changes of CPs due to the charge injection. Finally, created upon ab initio excited state dynamics, we report a computational methodology to explore the PV performance of donor-acceptor organic bulk heterojunctions (BHJ). This computational framework facilitates screening of the best donor-acceptor molecules and narrows down the list of potential candidates to be used in BHJ. We believe data-driven and multiscale modeling approaches established in this dissertation are important milestones for the design and structure-property prediction of CPs and organic BHJ, paving the way for developing the next generation of organic electronics