4,168 research outputs found

    Temperatures in cold rooms

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    Review of data on fishes of commercial and recreational fishing interest in the Great Barrier Reef Vol. 1

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    The first aim of this project was to synthesise and review all available data, both published and unpublished, relevant to the management of fish species of commercial and recreational interest on the Great Barrier Reef (GBR). The second was to make recommendations on research priorities based on the review.This is volume 1 of 2. Volume 2 can be found at http://hdl.handle.net/11017/56

    Exploring How Well UK Coach Education Meets the Needs of Women Sports Coaches

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    Inclusive and equitable processes are important to the development of sports coaching. The aim of this study was to explore how well UK coach education meets the needs of women sports coaches in order to make recommendations to further enhance the engagement of, and support for, aspiring and existing women coaches. The national governing bodies (NGBs) of four sports (Cycling, Equestrian, Gymnastics and Rowing) volunteered to participate and semi-structured interviews using the tenants of Appreciative Inquiry (AI) within a Self Determination Theory (SDT) framework were undertaken with 23 coaches, eight coach educators and five NGB officers. The data themed into an analytic structure derived from SDT comprising ‘Autonomy: Freedom to coach’, ‘Coaching competence’, and ‘Relatedness and belonging’. The coaches perceived potential benefit from enhanced relatedness and belonging within their sport with the findings suggesting that NGBs should embrace coach-led decision making in terms of the developmental topics which are important and should adopt the development of competence, rather than assessing technical understanding, as the foundational principle of more inclusive coach education. Future research should investigate the impact of the inclusive practices which are recommended within this investigation such as the softening of the technocratic focus of formal coach education

    The Complex Topology of Chemical Plants

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    We show that flowsheets of oil refineries can be associated to complex network topologies that are scale-free, display small-world effect and possess hierarchical organization. The emergence of these properties from such man-made networks is explained as a consequence of the currently used principles for process design, which include heuristics as well as algorithmic techniques. We expect these results to be valid for chemical plants of different types and capacities.Comment: 7 pages, 5 figures and 1 tabl

    `NMR Crystallization': in-situ NMR techniques for time-resolved monitoring of crystallization processes

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    Solid-state NMR spectroscopy is a well-established and versatile technique for studying structural and dynamic properties of solids, and there is considerable potential to exploit the power and versatility of solid-state NMR for in-situ studies of chemical processes. However, a number of technical challenges are associated with adapting this technique for in-situ studies, depending on the process of interest. Recently, an in-situ solid-state NMR strategy for monitoring the evolution of crystallization processes has been developed and has proven to be a promising approach for identifying the sequence of distinct solid forms present as a function of time during crystallization from solution, and for the discovery of new polymorphs. The latest development of this technique, called “CLASSIC” NMR, allows simultaneous measurement of both liquid-state and solid-state NMR spectra as a function of time, thus yielding complementary information on the evolution of both the liquid phase and the solid phase during crystallization from solution. This article gives an overview of the range of NMR strategies that are currently available for in-situ studies of crystallization processes, with examples of applications that highlight the potential of these strategies to deepen our understanding of crystallization phenomena

    OSETI with STACEE: A Search for Nanosecond Optical Transients from Nearby Stars

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    We have used the STACEE high-energy gamma-ray detector to look for fast blue-green laser pulses from the vicinity of 187 stars. The STACEE detector offers unprecedented light-collecting capability for the detection of nanosecond pulses from such lasers. We estimate STACEE's sensitivity to be approximately 10 photons per square meter at a wavelength of 420 nm. The stars have been chosen because their characteristics are such that they may harbor habitable planets and they are relatively close to Earth. Each star was observed for 10 minutes and we found no evidence for laser pulses in any of the data sets.Comment: 38 pages, 12 figures. Accepted for publication in Astrobiolog

    Spin dynamics of a trapped spin-1 Bose Gas above the Bose-Einstein transition temperature

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    We study collective spin oscillations in a spin-1 Bose gas above the Bose-Einstein transition temperature. Starting from the Heisenberg equation of motion, we derive a kinetic equation describing the dynamics of a thermal gas with the spin-1 degree of freedom. Applying the moment method to the kinetic equation, we study spin-wave collective modes with dipole symmetry. The dipole modes in the spin-1 system are found to be classified into the three type of modes. The frequency and damping rate are obtained as functions of the peak density. The damping rate is characterized by three relaxation times associated with collisions.Comment: 19 pages, 5 figur

    An Electron Paramagnetic Resonance (EPR) spectroscopy study on the γ-irradiation sterilization of the pharmaceutical excipient l-histidine: Regeneration of the radicals in solution

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    The effects of γ-radiation sterilization on the parenteral excipient L-histidine were analysed by means of EPR spectroscopy. The irradiation process was found to induce the formation of a deamination radical which was persistent in the solid state. The nature and reactivity of the radicals following dissolution in water was evaluated using spin-trapping EPR experiments. The deamination radical was found to regenerate in solution in the presence of trace metals, potentially leading to radical induced degradation reactions occurring up to an hour after the dissolution process. Understanding this process is significant for the improved design of parental pharmaceutical formulations in which unwanted radical reactions after γ radiation sterilization could lead to degradation of active ingredients

    Liquid-Solid Transition of Hard Spheres Under Gravity

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    We investigate the liquid-solid transition of two dimensional hard spheres in the presence of gravity. We determine the transition temperature and the fraction of particles in the solid regime as a function of temperature via Even-Driven molecular dynamics simulations and compare them with the theoretical predictions. We then examine the configurational statistics of a vibrating bed from the view point of the liquid-solid transition by explicitly determining the transition temperature and the effective temperature, T, of the bed, and present a relation between T and the vibration strength.Comment: 14 total pages, 4 figure

    Acceleration Schemes for Ab-Initio Molecular Dynamics and Electronic Structure Calculations

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    We study the convergence and the stability of fictitious dynamical methods for electrons. First, we show that a particular damped second-order dynamics has a much faster rate of convergence to the ground-state than first-order steepest descent algorithms while retaining their numerical cost per time step. Our damped dynamics has efficiency comparable to that of conjugate gradient methods in typical electronic minimization problems. Then, we analyse the factors that limit the size of the integration time step in approaches based on plane-wave expansions. The maximum allowed time step is dictated by the highest frequency components of the fictitious electronic dynamics. These can result either from the large wavevector components of the kinetic energy or from the small wavevector components of the Coulomb potential giving rise to the so called {\it charge sloshing} problem. We show how to eliminate large wavevector instabilities by adopting a preconditioning scheme that is implemented here for the first-time in the context of Car-Parrinello ab-initio molecular dynamics simulations of the ionic motion. We also show how to solve the charge-sloshing problem when this is present. We substantiate our theoretical analysis with numerical tests on a number of different silicon and carbon systems having both insulating and metallic character.Comment: RevTex, 9 figures available upon request, to appear in Phys. Rev.
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