30,351 research outputs found

    The spectrum of neutrons at 60 hg m(-2)

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    The rate of neutron interactions was measured for the energy range 7.5 to 60 MeV, using a 3.85 kg cell of liquid scintillator. The neutrons are selected by pulse shape discrimination, with anticoincidence counters used to reduce interference from muons transversing the scintillator. The observed flux is interpreted in terms of neutrons produced from environmental uranium and thorium, those resulting from the capture of negative muons in nuclei and those from fast muon interactions

    Mg II Absorption Characteristics of a Volume-Limited Sample of Galaxies at z ~ 0.1

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    We present an initial survey of Mg II absorption characteristics in the halos of a carefully constructed, volume-limited subsample of galaxies embedded in the spectroscopic part of the Sloan Digital Sky Survey. We observed quasars near sightlines to 20 low-redshift (z ~ 0.1), luminous M_r <= -20.5 galaxies in SDSS DR4 and DR6 with the LRIS-B spectrograph on the Keck I telescope. The primary systematic criteria for the targeted galaxies are a redshift z >~ 0.1 and the presence of an appropriate bright background quasar within a projected 75 kpc/h of its center, although we preferentially sample galaxies with lower impact parameters and slightly more star formation within this range. Of the observed systems, six exhibit strong [EW(2796) >= 0.3 Ang.] Mg II absorption at the galaxy's redshift, six systems have upper limits which preclude strong Mg II absorption, while the remaining observations rule out very strong [EW(2796) >= 1-2 Ang] absorption. The absorbers fall at higher impact parameters than many non-absorber sightlines, indicating a covering fraction f_c = 0.3-Angstrom absorbers at z ~ 0.1, even at impact parameters <= 35 kpc/h (f_c ~ 0.25). The data are consistent with a possible dependence of covering fraction and/or absorption halo size on the environment or star-forming properties of the central galaxy.Comment: accepted for publication in A

    Progressive (dis)ability: the experience of living with Charcot-Marie-Tooth disease

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    This thesis is an Interpretative Phenomenological Analysis of the experiences of six women living with Charcot-Marie-Tooth (CMT), an inherited degenerative neurological condition with a range of debilitating symptoms. It is the first ever in-depth qualitative study into the lived experience of CMT, which is relatively common yet largely unknown. This is “Paradigm II” disability research (Olkin, 1999) that listens to the voices of those with disabilities to advocate for improved conditions, services and status in the world. Those who are disabled are empowered to speak for themselves. The researcher, too, has CMT and another progressive neurological condition, Parkinson’s. The women’s stories are analysed alongside his own autobiographical narrative. Four themes are identified and discussed, drawing on literature from across the fields of psychology, psychotherapy and disability studies: loss, discrimination, identity and growth. Arising from these findings, the concept of “disability apartheid” is developed into a “two worlds” model which can be used to describe how psychological factors such as acceptance and shame can impact the ways in which those with disability identify and engage with a disabling world and with their own lives. The researcher argues for “one world” where all individual capabilities and limitations are respected. The findings also inform 12 clinical recommendations for counselling psychologists, psychotherapists or other healthcare professionals working with CMT, other neurological or progressive physical conditions, or disability

    Contributions of Vacuum and Plasmon Modes to the Force on a Small Sphere near a Plate

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    The force on a small sphere with a plasma model dielectric function and in the presence of a perfectly reflecting plane is considered. The contribution of both the vacuum modes of the quantized electromagnetic field and of plasmon modes in the sphere are discussed. In the case that the plasmon modes are in their ground state, quasi-oscillatory terms from the vacuum and plasmon parts cancel one another, leading a monotonic attractive force. If the plasmon modes are not in the ground state, the net force is quasi-oscillatory. In both cases, the sphere behaves in the same way as does an atom in either its ground state or an excited state.Comment: 7 pages, no figures, talk presented at "Quantum Fields under External Conditions - 2005", Barcelona, Spain, September 200

    Beyond the happy sheets! Evaluating learning in information skills teaching

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    This paper reviews three years of data measuring students' immediate reactions to a computer-assisted learning package in information skills and reports on work in progress to establish a more comprehensive programme of evaluation which will assess the longer term impact on learning of both the courseware itself and the way the courseware is delivered to students. The GAELS courseware was developed in the late 1990s as part of a collaborative project between the Universities of Glasgow and Strathclyde, with funding from the Scottish Higher Education Funding Council. The courseware was designed to teach higher level information skills and was initially developed for use with postgraduate engineering students; it has subsequently been adapted for use with students in other subject areas, including biological and physical sciences, and has been embedded for several years now in workshop sessions undertaken with postgraduate and undergraduate students across the Faculties of Science and Engineering at the University of Strathclyde. The courseware is introduced at the start of the academic session and made available on the Web so that students can use it as needed during their course and project work. During the first year, the courseware was used in isolation from other teaching methods (although a librarian was present to support students), whilst in the second and third years it was integrated into more traditional workshop-style teaching sessions (led by a librarian). Following work described in Joint (2003), library staff now wish to assess the longer term impact on learning of both the courseware itself and the way the courseware is delivered to students. However, the existing evaluation data does not adequately support this type of assessment. Teaching sessions are routinely evaluated by means of simple feedback forms, with four questions answered using a five-point Likert scale, collected at the conclusion of each session. According to Fitzpatrick (1998), such feedback forms measure students' reactions and represent but the first level of evaluation. Learning, which can be defined as the extent to which a student changes attitudes, improves knowledge and/or increases skill as a result of exposure to the training, is the second level and is not being measured with these forms. A more comprehensive programme of evaluation, including logging usage of the courseware outside teaching sessions and follow-up of students several months after their introduction to the courseware, is now being established to support a more meaningful assessment of impact of the courseware on student learning
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