3,650 research outputs found

    Thermal Management of Satellite Electronics via Gallium Phase Change Heat Sink Devices

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    The purpose of this research was to determine the effectiveness and feasibility of additively manufactured heat sinks using gallium as a phase change material in the thermal management of satellite electronics. A design was created based on the footprint of an Astronautical Development, LLC Lithium 1 UHF radio and six heat sinks were additively manufactured; two each of stainless steel 316, Inconel 718, and ULTEM 9085. Each heat sink was filled with gallium for testing purposes. Models were created to simulate the behavior of the heat transfer and phase change processes occurring within the heat sink. Additionally, laboratory data was gathered on the actual processes occurring. Testing was carried out in a thermal vacuum chamber with the use of film heaters that were attached to the heat sink to simulate a radio in transmitting mode while a satellite is in contact with a ground station. Finally, temperature profiles of the laboratory data were created to gain insight into the characteristics of the phase change process and its effectiveness in thermal management of satellite electronics

    Requiem for the Transient

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    Requiem for the Transient is a six-movement piece of music for full orchestra and choir. The six movements are the “Prelude,” “Introit,” “Sequentia,” “Agnus Dei,” “Lux Aeterna,” and “In Paradisum,” As with most Requiems, the music is a setting of prayers from the Roman Missal. Historically composers have used various prayer choices, sometimes even including texts outside of the Missal. Requiem for the Transient contains only one source of text outside of the Missal; the first movement, “Prelude”, uses text from the New King James version of Ecclesiastes 12:1-7. This document will compare and contrast Requiem for the Transient with other works from the twentieth and twenty-first century with a focus on the melodic, harmonic, and rhythmic construction of key sections of music. The Requiem will also be compared to other notable Requiems ranging back as far as Mozart. This thesis will provide an explanation of compositional approaches to show the musical influences that have directly, or indirectly, influenced the writing of Requiem for the Transient

    Evading the Patronage Trap

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    Why have Latin American democracies proven unable to confront the structural inequalities that cripple their economies and stymie social mobility? Brian Palmer-Rubin contends that we may lay the blame on these countries’ systems of interest representation, which exhibit “biased pluralism,” a system in which the demands of organizations representing economic elites—especially large corporations—predominate. A more inclusive model of representation would not only require a more encompassing and empowered set of institutions to represent workers, but would also feature spaces for non-eliteproducers—such as farmers and small-business owners to have a say in sectoral economic policies. With analysis drawing on over 100 interviews, an original survey, and official government data, this book focuses on such organizations and develops an account of biased pluralism in developing countries typified by the centrality of patronage—discretionarily allocated state benefits. Rather than serving as conduits for demand-making about development models, political parties and interest organizations often broker state subsidies or social programs, augmenting the short-term income of beneficiaries, but doing little to improve their long-term economic prospects. When organizations become diverted into patronage politics, the economic demands of the masses go unheard in the policies that most affect their lives, and along the way, their economic interests go unrepresented

    Electrical brain responses reveal sequential constraints on planning during music performance

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    Funding: National Science Foundation Graduate Research Fellowship to B.M. Canada Research Chairs grant and Natural Sciences and Engineering Research Council of Canada grant 298173 to C.P.Peer reviewe

    Auditory N1 reveals planning and monitoring processes during music performance

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    The current study investigated the relationship between planning processes and feedback monitoring during music performance, a complex task in which performers prepare upcoming events while monitoring their sensory outcomes. Theories of action planning in auditory‐motor production tasks propose that the planning of future events co‐occurs with the perception of auditory feedback. This study investigated the neural correlates of planning and feedback monitoring by manipulating the contents of auditory feedback during music performance. Pianists memorized and performed melodies at a cued tempo in a synchronization‐continuation task while the EEG was recorded. During performance, auditory feedback associated with single melody tones was occasionally substituted with tones corresponding to future (next), present (current), or past (previous) melody tones. Only future‐oriented altered feedback disrupted behavior: Future‐oriented feedback caused pianists to slow down on the subsequent tone more than past‐oriented feedback, and amplitudes of the auditory N1 potential elicited by the tone immediately following the altered feedback were larger for future‐oriented than for past‐oriented or noncontextual (unrelated) altered feedback; larger N1 amplitudes were associated with greater slowing following altered feedback in the future condition only. Feedback‐related negativities were elicited in all altered feedback conditions. In sum, behavioral and neural evidence suggests that future‐oriented feedback disrupts performance more than past‐oriented feedback, consistent with planning theories that posit similarity‐based interference between feedback and planning contents. Neural sensory processing of auditory feedback, reflected in the N1 ERP, may serve as a marker for temporal disruption caused by altered auditory feedback in auditory‐motor production tasks.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/136038/1/psyp12781_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/136038/2/psyp12781.pd

    Incentives for Organizational Participation: A Recruitment Experiment in Mexico

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    While the presence of a strong civil society is recognized as desirable for democracies, an important question is what motivates citizens to join organizations. This article presents novel experimental evidence on the conditions under which citizens join interest organizations. We presented 1,400 citizens in two Mexican states with fliers promoting a new local interest organization. These fliers contain one of four randomly selected recruitment appeals. We find evidence that both brokerage of state patronage and demand-making for local public goods are effective recruitment appeals. The effect for patronage brokerage is especially pronounced among respondents with prior organizational contact, supporting our hypothesis of a “particularistic socialization” effect wherein organizational experience is associated with greater response to selective material benefits. Our findings suggest that under some conditions, rather than generating norms of other-regarding, interest organizations can reinforce members’ individualistic tendencies

    Hearing the Voice of Medical Students Worldwide

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    The Student Forum, a new section of PLoS Medicine, is a space where medical students from across the world can exchange ideas about the critical issues affecting health and health care from their unique perspectiv
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