174 research outputs found
Development of Oxidizer Flow Control for use in Hybrid Rocket Motors of the Scientific Sounding Rocket Scale
To successfully build a rocket engine with variable thrust you must devise a reliable and robust oxidizer flow control system. The goal of this thesis is to contribute to the goal of building a variable thrust (throttled) hybrid rocket engine, which could eventually be used to power scientific sounding rockets. A variable thrust hybrid engine would increase reusability, flexibility, and capability of almost any small rocket.
Specifically, this thesis work regards the development of the closed loop oxidizer flow control system. To do this, a small test rig was built in the lab that consists of all the components in an actual rocket engine except for the combustion chamber. Using this apparatus the behavior of water in the system was analyzed, including the characterization of the oxidizer flow control valve and the response of the system to various controller parameters. By having a process perfected for characterizing a system with water it makes the process much easier when done with the more exotic oxidizer materials such as nitrous oxide and carbon dioxide
THE USE OF DISTRACTION: DOOMSCROLLING, LOSING TIME, AND DIGITAL WELL-BEING IN PANDEMIC SPACE-TIMES
In the space-times of the COVID-19 global health crisis, how have our relationships with smartphones changed? How do popular discourses designate mundane engagements with digital technologies as healthy or unhealthy, and how are these notions of wellness practiced? This thesis draws upon an online survey of smartphone users residing in Kentucky, and a review of marketing, journalistic, and academic literature to establish current understandings of âdigital well-beingâ. The paper then analyzes interviews with Kentucky smartphone users who were asked to track their screen time for a one-week period. This project reveals normative conceptions of well-being and the role of smartphone and screen time metrics in producing ideas of digital wellness. The thesis draws upon health geographies, disability studies, media studies, and STS to argue that the common heuristics of digital wellness are insufficient to either understand or improve subjective well-being, and that a relational and ecological analysis of âdigital well-beingâ allows us to re-evaluate normative prescriptions of care. Mobilizing theories of attention and neoliberal biopolitics, the paper connects normative notions of attentiveness and wellness to demonstrate a specific assemblage of âdigital well-being,â and theorizes distraction as a set of ambivalent, unruly practices which might disrupt it
Reconfiguring Absence: Daniel Libeskind's Jewish Museum in Berlin and the Rhetorical Negotiation of Cultural Display
This study traces the development of the Jewish Museum Berlin from its inception as the winning entry in a competition for an extension to the Berlin Museum in the summer of 1989 to 2005. Tracking Daniel Libeskindâs design inspirations, public arguments over continuation of the building and its eventual use, I argue that a consistent argumentative trope, characterized by Ernst Blochâs concept of anticipatory illumination, shows up in these various conversations and influences the buildingâs eventual use as the Jewish Museum Berlin. The rhetoric of anticipatory illumination, in this case, shifts over time, first emphasizing Jewish cultural absence in Berlin and the need to make that absence visible, but later pushing cultural absence to the background in favor of expressing the need for multicultural tolerance in Germany and beyond. The resulting museum, the Jewish Museum Berlin, combined the specificity of the history of the former in its curatorial design with injunctions for wider concern about intolerance in contemporary societies around the world. The author argues that the shift produces a âdoubled heterotopiaâ in the arrangement of the museum that ultimately is effective for addressing the diverse audiences for the Jewish Museum Berlin. The case study emphasizes that public art and architecture projects can be rich sites of rhetorical invention worthy of close study over the time of their development
How does gene flow limit local adaptation at a species range-edge? An artificial selection Drosophila model
Gene flow has the potential to create species range limits by impeding adaptation to selective pressures at the range-edge, but it is unclear whether there is a threshold level of gene flow that causes this effect. This gene swamping hypothesis was tested using laboratory populations of Drosophila melanogasterunder selection for desiccation resistance, and subject to a gradient of migration from unselected populations. Desiccation tolerance was impeded across the entire migration gradient, and populations receiving intermediate levels of migration exhibited no tolerance for desiccation stress, following twelve selection events. Female, but not male, flies increased desiccation tolerance following selection by reducing water loss rates, but not by carrying more water or becoming more tolerant of dehydration. This pattern is likely due to selection for increased female body size. Thus, intermediate levels of gene flow, in particular, have the potential to establish a species range-limit by confounding the response to selection
Alien Registration- Tardif, Jeannette (Auburn, Androscoggin County)
https://digitalmaine.com/alien_docs/30339/thumbnail.jp
Perceived similarity of desired intimacy in same-sex couples
2013 Summer.Includes bibliographical references.Past literature has discussed gender differences in romantic partners' desires for intimacy and has suggested that these gender differences have negative effects on some relationships. Much of this literature has discussed heterosexual relationships. The current study sought to explore the validity of these claims within same-sex relationships. Participants completed surveys assessing their own desires for intimacy, their perceptions of their partners' desires for intimacy, and relationship outcome variables (satisfaction/commitment). Results indicated that perceived similarity to one's partner in overall desired intimacy is associated with relationship satisfaction and commitment. The effects of perceived similarity varied across types of intimacy, such that perceived similarity in desires for intellectual intimacy and recreational intimacy were most associated with relationship outcome variables, though slightly differently for men and women. The importance of direction of perceived discrepancy was also explored. Comparisons to previous research and implications for counseling and future research are discussed
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