4,900 research outputs found

    Teaching and Professional Fellowship Report 2004/5 : Improving reflective practice through learning journals and virtual learning environments.

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    This paper describes work carried out within the Fellowship with the intention of increasing student achievement by improving students’ abilities to reflect, evaluate, and act upon their evaluations. I also sought to improve communication across a large Course. Previous external verifiers have recognised the lack of evaluative practice within Foundation Courses as a national issue. My work since 2002 has involved the introduction, implementation and development of new learning tools. These tools have evolved from the very simple: An A5 pre-printed journal, written into by students, called the Thinktank, to more complex virtual learning environments (VLE) within the University’s Blackboard site. A survey of students’ final major project portfolios indicates that students who use these tools effectively are more likely to achieve merit & distinction grades in their final examinations. To create the VLE I built and activated a Foundation Studies Blackboard site. I have found that both the Thinktank and Blackboard have merit and have attempted to combine their use across the course. I piloted a number of Blackboard-specific assignments to encourage on-line peer group learning through the use of asynchronous discussion boards. I observed a number of advantages in using discussion boards, which facilitate a combination of live, (slowed) discussion, and personal reflective practice. The use of discussion boards also brings more benefits for learners such as flexibility of time and place, more time to engage in an online debate, transparency, a certain levelling of different language abilities, automatic archiving: (students can revisit the discussion at any point). Taking discussion board ideas back into live studio debates produced a high level of student engagement. A more open-ended pilot, the moblog, allows students working on an expressive, selfdirected project to send SMS messages to a webpage within the Blackboard site. With this pilot I was interested in exploring the potential of the mobile phone as ‘sketchbook/ journal’. Students were positive about the pilot and despite the limitations of SMS messaging, quickly established a recognisable 'voice' and the beginnings of an online communit

    Reaction mechanisms of pair transfer

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    The mechanisms of nuclear transfer reactions are described for the transfer of two nucleons from one nucleus to another. Two-nucleon overlap functions are defined in various coordinate systems, and their transformation coefficients given between coordinate systems. Post and prior couplings are defined for sequential transfer mechanisms, and it is demonstrated that the combination of `prior-post' couplings avoids non-orthogonality terms, but does not avoid couplings that do not have good zero-range approximations. The simultaneous and sequential mechanisms are demonstrated for the 124^{124}Sn(p,t)122^{122}Sn reaction at 25 MeV using shell-model overlap functions. The interference between the various simultaneous and sequential amplitudes is shown.Comment: 14 pages, 3 figures, chapter 34 in "50 Years of Nuclear BCS", edited by R. A. Broglia and V. Zelevinsky: ISBN 978-981-4412-48-3 Uses WS macros (included). Corrected text and calculations as in the published versio

    Detailed Abundances of 15 Stars in the Metal-Poor Globular Cluster NGC 4833

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    We have observed 15 red giant stars in the relatively massive, metal-poor globular cluster NGC 4833 using the Magellan Inamori Kyocera Echelle spectrograph at Magellan. We calculate stellar parameters for each star and perform a standard abundance analysis to derive abundances of 43 species of 39 elements, including 20 elements heavier than the iron group. We derive = -2.25 +/- 0.02 from Fe I lines and = -2.19 +/- 0.013 from Fe II lines. We confirm earlier results that found no internal metallicity spread in NGC 4833, and there are no significant star-to-star abundance dispersions among any elements in the iron group (19 <= Z <= 30). We recover the usual abundance variations among the light elements C, N, O, Na, Mg, Al, and possibly Si. The heavy-element distribution reflects enrichment by r-process nucleosynthesis ([Eu/Fe] = +0.36 +/- 0.03), as found in many other metal-poor globular clusters. We investigate small star-to-star variations found among the neutron-capture elements, and we conclude that these are probably not real variations. Upper limits on the Th abundance, log epsilon (Th/Eu) < -0.47 +/- 0.09, indicate that NGC 4833, like other globular clusters where Th has been studied, did not experience a so-called "actinide boost."Comment: Accepted for publication in MNRAS. Version 2 adds final publication referenc

    Quantum mechanics and consciousness: Thoughts on a causal correspondence theory

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    Which way does causation proceed? The pattern in the material world seems to be upward: particles to molecules to organisms to brains to mental processes. In contrast, the principles of quantum mechanics allow us to see a pattern of downward causation. These new ideas describe sets of multiple levels in which each level influences the levels below it through generation and selection. Top-down causation makes exciting sense of the world: we can find analogies in psychology, in the formation of our minds, in locating the source of consciousness, and even in the possible logic of belief in God

    A comparative study of formalisms for programming language definition : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Computer Science at Massey University

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    This study looks at a number of methods for defining the full syntax and semantics of computer programming languages. The syntax, especially the nature of context-dependent conditions in it, is first examined, then some extensions of context-free grammars are compared to see to what extent they can encompass the full context-conditions of typical programming languages. It is found that several syntax extensions are inadequate in this regard, and that the ability to calculate complicated functions and conditions, and to eventually delete the values of such functions, is needed. This ability may be obtained either by allowing unrestricted rules and meta-variables in the phrase-structure, or by associating mathematical functions either with individual production rules or with the whole context-free structure, to transform it into an 'abstract syntax'. Since the form of a definition of a programming language semantics depends critically on how one conceives "meaning", five main types of semantics are considered: these are called 'natural', 'prepositional', 'functional', and 'structural' semantics, as well as a semantics based on string rewriting rules. The five types are compared for their success in defining the semantics of computing languages, of the example Algol-like language ALEX in particular. Among other conclusions, it is found that the semantics of structures and computations on structures is the only type sufficiently comprehensive, precise, and readable

    Dynamical phase transitions in one-dimensional hard-particle systems

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    We analyse a one-dimensional model of hard particles, within ensembles of trajectories that are conditioned (or biased) to atypical values of the time-averaged dynamical activity. We analyse two phenomena that are associated with these large deviations of the activity: phase separation (at low activity) and the formation of hyperuniform states (at high activity). We consider a version of the model which operates at constant volume, and a version at constant pressure. In these non-equilibrium systems, differences arise between the two ensembles, because of the extra freedom available to the constant-pressure system, which can change its total density. We discuss the relationships between different ensembles, mechanical equilibrium, and the probability cost of rare density fluctuations.Comment: 11 pages, 11 figure

    Assembling and enriching digital library collections

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    People who create digital libraries need to gather together the raw material, add metadata as necessary, and design and build new collections. This paper sets out the requirements for these tasks and describes a new tool that supports them interactively, making it easy for users to create their own collections from electronic files of all types. The process involves selecting documents for inclusion, coming up with a suitable metadata set, assigning metadata to each document or group of documents, designing the form of the collection in terms of document formats, searchable indexes, and browsing facilities, building the necessary indexes and data structures, and putting the collection in place for others to use. Moreover, different situations require different workflows, and the system must be flexible enough to cope with these demands. Although the tool is specific to the Greenstone digital library software, the underlying ideas should prove useful in more general contexts

    Enzymatic transhalogenation of dendritic RGD peptide constructs with the fluorinase

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    We thank EPSRC and the Scottish Imaging Network (SINAPSE) for grants. DO’H thanks the Royal Society for a Wolfson Research Merit Award and ST is grateful to the John and Kathleen Watson Scholarship for financial support. We are grateful to Dr Catherine Botting and Dr Sally Shirran of the St Andrews Mass Spectrometry Service for MALDI-MS acquisitions. We also thank Dr Sally Pimlott of the University of Glasgow for the use of radiochemistry facilities. Open access via RSC Gold for Gold.Peer reviewedPublisher PD

    A Differential Abundance Analysis of Very Metal-Poor Stars

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    We have performed a differential, line-by-line, chemical abundance analysis, ultimately relative to the Sun, of nine very metal-poor main sequence halo stars, near [Fe/H]=-2 dex. Our abundances range from 2.66[Fe/H]1.40-2.66\leq\mathrm{[Fe/H]}\leq-1.40 dex with conservative uncertainties of 0.07 dex. We find an average [α\alpha/Fe]=0.34±0.09=0.34\pm0.09 dex, typical of the Milky Way. While our spectroscopic atmosphere parameters provide good agreement with HST parallaxes, there is significant disagreement with temperature and gravity parameters indicated by observed colors and theoretical isochrones. Although a systematic underestimate of the stellar temperature by a few hundred degrees could explain this difference, it is not supported by current effective temperature studies and would create large uncertainties in the abundance determinations. Both 1D and \langle3D\rangle hydrodynamical models combined with separate 1D non-LTE effects do not yet account for the atmospheres of real metal-poor MS stars, but a fully 3D non-LTE treatment may be able to explain the ionization imbalance found in this work.Comment: 18 pages, 13 tables, 5 figures, Accepted in Ap
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