3,296 research outputs found

    Mentor-Teaching in the English Classroom

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    This dissertation is a rhetorical analysis of the theories and practices surrounding student-centered mentor-teaching. I examine textual representations of the teacher/student relationship as well as theories and practices involved in the discursive formation of teacher/student relationships, examining the intersection (or lack thereof) between the ways we as researchers talk about teacher/student relationship formation and the way(s) such relationships form in the “real world” of the English classroom. This institutional critique of teacher/student relationships draws on the works of ancient rhetorical scholars like Quintillian and Socrates, and on the post-1980 scholarship of Robert Connors, Lad Tobin, bell hooks, Paulo Freire, Parker J. Palmer, Mike Rose, Wendy Bishop, Louise Rosenblatt, Jeffrey Berman, and Peter Elbow. These scholars have all provided helpful models for me as I have framed my own beliefs about the value of expressive writing, the usefulness of writing conferences, the need for teacher vulnerability as a model for students’ expressive writing, the appropriateness of various relational settings beyond the classroom, and the ways grading/responding to student writing can either promote or inhibit a trusting student/teacher bond. While all of these scholars have contributed to my own beliefs and ideas, I am merely identifying and classifying pedagogical movements; rather, I am synthesizing these movements’ theories and practices in order to formulate an overall critique of the strengths and weaknesses of the various approaches. I also draw heavily upon the theoretical underpinnings of psychoanalysis, feminism, reader-response criticism, and composition studies to weave together a synthesized working model of mutually beneficial teacher/student relationships as they pertain to the high school and college English classrooms. Ultimately, I suggest my own contributions to the existing scholarship that will call for a mixture of both bolder pedagogical approaches and greater relational caution, depending upon the concept and the student(s) involved. I conclude with suggestions for utilizing teacher research to formulate new theories and practices for mentor-teaching in the English classroom

    A target for production of radioxenons

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    A liquid cesium target has been developed which allows the production and separate identification of the neutron deficient isotopes of xenon. The present report describes irradiations utilizing 34 to 41 MeV protons to produce millicurie quantities of Xe-127 and Xe-129m. At higher energies, however, the target could be used without modification to produce xenon isotopes as light as 119

    A review of single-mode fiber optofluidics

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    We review the field we describe as “single-mode fiber optofluidics” which combines the technologies of microfluidics with single-mode fiber optics for delivering new implementations of well-known single-mode optical fiber devices. The ability of a fluid to be easily shaped to different geometries plus the ability to have its optical properties easily changed via concentration changes or an applied electrical or magnetic field offers potential benefits such as no mechanical moving parts, miniaturization, increased sensitivity and lower costs. However, device fabrication and operation can be more complex than in established single-mode fiber optic devices

    Limitations in Predicting Radiation-Induced Pharmaceutical Instability during Long-Duration Spaceflight

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    As human spaceflight seeks to expand beyond low-Earth orbit, NASA and its international partners face numerous challenges related to ensuring the safety of their astronauts, including the need to provide a safe and effective pharmacy for long-duration spaceflight. Historical missions have relied upon frequent resupply of onboard pharmaceuticals; as a result, there has been little study into the effects of long-term exposure of pharmaceuticals to the space environment. Of particular concern are the long-term effects of space radiation on drug stability, especially as missions venture away from the protective proximity of the Earth. Here we highlight the risk of space radiation to pharmaceuticals during exploration spaceflight, identifying the limitations of current understanding. We further seek to identify ways in which these limitations could be addressed through dedicated research efforts aimed towards the rapid development of an effective pharmacy for future spaceflight endeavors.Comment: in press, Nature Microgravit

    Comparison Testings between Two High-temperature Strain Measurement Systems

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    An experimental evaluation was conducted at NASA Lewis Research Center to compare and contrast the performance of a newly developed resistance strain gage, the PdCr temperature-compensated wire strain gage, to that of a conventional high-temperature extensometry. The evaluation of the two strain measurement systems was conducted through the application of various thermal and mechanical loading spectra using a high-temperature thermomechanical uniaxial testing system equipped with quartz lamp heating. The purpose of the testing was not only to compare and contrast the two strain sensors but also to investigate the applicability of the PdCr strain gage to the testing environment typically employed when characterizing the high-temperature mechanical behavior of structural materials. Strain measurement capabilities to 8OO C were investigated with a nickel base superalloy IN100 substrate material, and application to titanium matrix composite (TMC) materials was examined with the SCS-6/Ti-15-3 08 system. PdCr strain gages installed by three attachment techniques, namely, flame spraying, spot welding and rapid infrared joining were investigated

    Stability and Instability of Extreme Reissner-Nordstr\"om Black Hole Spacetimes for Linear Scalar Perturbations I

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    We study the problem of stability and instability of extreme Reissner-Nordstrom spacetimes for linear scalar perturbations. Specifically, we consider solutions to the linear wave equation on a suitable globally hyperbolic subset of such a spacetime, arising from regular initial data prescribed on a Cauchy hypersurface crossing the future event horizon. We obtain boundedness, decay and non-decay results. Our estimates hold up to and including the horizon. The fundamental new aspect of this problem is the degeneracy of the redshift on the event horizon. Several new analytical features of degenerate horizons are also presented.Comment: 37 pages, 11 figures; published version of results contained in the first part of arXiv:1006.0283, various new results adde

    Preliminary results of fast neutron treatments in carcinoma of the pancreas

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    A group of 30 patients with adenocarcinoma of the pancreas including some patients with very advanced disease, were treated with the so-called mixed beam modality employing photon treatments three times per week and neutron treatments twice a week. Two hundred Rads or equivalent Rads (RBE 3.3) were given in daily fractions aiming at a total dose of 6000 Rads in 6 to 8 weeks. The treatments were well tolerated and significant palliation was achieved in 26 to 30 cases. Twelve months survival was 33 percent with a median survival of 7 months or 210 days. Treatment techniques and localization procedures are discussed

    Limitations in Predicting the Space Radiation Health Risk for Exploration Astronauts

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    Despite years of research, understanding of the space radiation environment and the risk it poses to long-duration astronauts remains limited. There is a disparity between research results and observed empirical effects seen in human astronaut crews, likely due to the numerous factors that limit terrestrial simulation of the complex space environment and extrapolation of human clinical consequences from varied animal models. Given the intended future of human spaceflight, with efforts now to rapidly expand capabilities for human missions to the moon and Mars, there is a pressing need to improve upon the understanding of the space radiation risk, predict likely clinical outcomes of interplanetary radiation exposure, and develop appropriate and effective mitigation strategies for future missions. To achieve this goal, the space radiation and aerospace community must recognize the historical limitations of radiation research and how such limitations could be addressed in future research endeavors. We have sought to highlight the numerous factors that limit understanding of the risk of space radiation for human crews and to identify ways in which these limitations could be addressed for improved understanding and appropriate risk posture regarding future human spaceflight.Comment: Accepted for publication by Nature Microgravity (2018
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