455 research outputs found

    Process Safety Competence Assurance

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    PresentationCompetence is a critical component of an organization’s success—one that is also very relevant for process safety. In fact, process safety competence can help ensure compliance with regulatory requirements and can be an important business improvement driver, particularly when it comes to process safety risk. Competence is often confused with knowledge; therefore, it can be difficult to assess competence levels. However, having a well-defined framework to assess process safety competence across the organization can offer many benefits, including helping the organization to: Identify gaps in organizational understanding and competence, and uncover opportunities to close those gaps; Ensure that personnel have the appropriate process safety competence levels (i.e., knowledge, experience, education and training); Ensure correct decisions and actions are taken to prevent incidents; Facilitate training to help effectively manage process safety in the workplace; and Create a sustainable model to support ongoing staffing and succession planning. This paper introduces a structured and scalable approach to process safety competence assurance, which is modeled using recognized industry guidelines, publications, and experience. This approach is fit-for-purpose and provides a framework designed to encourage intentional learning and development to close identified process safety competence gaps. The ultimate outcome of this approach is a competent staff who help recognize and drive process safety improvement

    Tests for exponentiality against NBUE alternatives: a Monte Carlo comparison

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    Testing of various classes of life distributions has been addressed in the literature for more than 45 years. In this paper, we consider the problem of testing exponentiality (which essentially implies no ageing) against positive ageing which is captured by the fairly large class of new better than used in expectation (NBUE) distributions. These tests of exponentiality against NBUE alternatives are discussed and compared. The empirical size of the tests is obtained by simulations. Power comparisons for different popular alternatives are done using Monte Carlo simulations. These comparisons are made for both small and large sample sizes. The paper concludes with a discussion in which suggestions are made regarding the choices of the test when a particular alternative is suspected

    A neuroendocrine role for chemerin in hypothalamic remodelling and photoperiodic control of energy balance

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    YesLong-term and reversible changes in body weight are typical of seasonal animals. Thyroid hormone (TH) and retinoic acid (RA) within the tanycytes and ependymal cells of the hypothalamus have been implicated in the photoperiodic response. We investigated signalling downstream of RA and how this links to the control of body weight and food intake in photoperiodic F344 rats. Chemerin, an inflammatory chemokine, with a known role in energy metabolism, was identified as a target of RA. Gene expression of chemerin (Rarres2) and its receptors were localised within the tanycytes and ependymal cells, with higher expression under long (LD) versus short (SD) photoperiod, pointing to a physiological role. The SD to LD transition (increased food intake) was mimicked by 2 weeks of ICV infusion of chemerin into rats. Chemerin also increased expression of the cytoskeletal protein vimentin, implicating hypothalamic remodelling in this response. By contrast, acute ICV bolus injection of chemerin on a 12h:12h photoperiod inhibited food intake and decreased body weight with associated changes in hypothalamic neuropeptides involved in growth and feeding after 24hr. We describe the hypothalamic ventricular zone as a key site of neuroendocrine regulation, where the inflammatory signal, chemerin, links TH and RA signaling to hypothalamic remodeling.BBSRC (grant number BB/K001043/1) and the Scottish Government

    Pions in isospin asymmetric nuclei

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    Using a pair of the lightest mirror nuclei, 3^3He and 3^3H, we study the effect of the medium modification of pion fields on the flavor non-singlet structure function. The change of the pion fields leads to an enhancement of the flavor asymmetry of the antiquark distributions in a nucleus.Comment: 14 pages (4 figures

    Pion Content of the Nucleon as seen in the NA51 Drell-Yan experiment

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    In a recent CERN Drell-Yan experiment the NA51 group found a strong asymmetry of uˉ\bar u and dˉ\bar d densities in the proton at x≃0.18x\simeq0.18. We interpret this result as a decisive confirmation of the pion-induced sea in the nucleon.Comment: 10 pages + 3 figures, Preprint KFA-IKP(TH)-1994-14 .tex file. After \enddocument a uu-encodeded Postscript file comprising the figures is appende

    Three-Charge Black Holes on a Circle

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    We study phases of five-dimensional three-charge black holes with a circle in their transverse space. In particular, when the black hole is localized on the circle we compute the corrections to the metric and corresponding thermodynamics in the limit of small mass. When taking the near-extremal limit, this gives the corrections to the constant entropy of the extremal three-charge black hole as a function of the energy above extremality. For the partial extremal limit with two charges sent to infinity and one finite we show that the first correction to the entropy is in agreement with the microscopic entropy by taking into account that the number of branes shift as a consequence of the interactions across the transverse circle. Beyond these analytical results, we also numerically obtain the entire phase of non- and near-extremal three- and two-charge black holes localized on a circle. More generally, we find in this paper a rich phase structure, including a new phase of three-charge black holes that are non-uniformly distributed on the circle. All these three-charge black hole phases are found via a map that relates them to the phases of five-dimensional neutral Kaluza-Klein black holes.Comment: 58 pages, 10 figures; v2: Corrected typos, version appearing in JHE

    Systematic Cu-63 NQR studies of the stripe phase in La(1.6-x)Nd(0.4)Sr(x)CuO(4) for 0.07 <= x <= 0.25

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    We demonstrate that the integrated intensity of Cu-63 nuclear quadrupole resonance (NQR) in La(1.6-x)Nd(0.4)Sr(x)CuO(4) decreases dramatically below the charge-stripe ordering temperature T(charge). Comparison with neutron and X-ray scattering indicates that the wipeout fraction F(T) (i.e. the missing fraction of the integrated intensity of the NQR signal) represents the charge-stripe order parameter. The systematic study reveals bulk charge-stripe order throughout the superconducting region 0.07 <= x <= 0.25. As a function of the reduced temperature t = T/T(charge), the temperature dependence of F(t) is sharpest for the hole concentration x=1/8, indicating that x=1/8 is the optimum concentration for stripe formation.Comment: 10 pages of text and captions, 11 figures in postscript. Final version, with new data in Fig.

    Economic evaluation of diagnosing and excluding ectopic pregnancy

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    BACKGROUND: The diagnosis of ectopic pregnancy in women presenting in early pregnancy is often protracted, relying on costly investigations that are psychologically burdensome to the patient. The aim of this study was to evaluate the financial costs to the health services in Scotland of the current methods used to diagnose and exclude ectopic pregnancy, and compare these with that of a theoretical single diagnostic serum biomarker. METHODS: We conducted a retrospective cost description analysis (with and without costs of diagnostic laparoscopy) of the healthcare costs incurred by all patients presenting to a large Scottish teaching hospital between June and September 2006 with pain and bleeding in early pregnancy, where ectopic pregnancy was not excluded. Additionally, a cost minimisation analysis was performed of the costs of current ectopic pregnancy investigations versus those of a theoretical single diagnostic serum biomarker. This included sensitivity analyses where the biomarker was priced at increasing values and assumed to have less than 100% diagnostic sensitivity and specificity. RESULTS: 175 patients were eligible to be included in the analysis. 47% of patients required more than 3 visits to diagnose or exclude ectopic pregnancy. The total yearly cost for diagnosing and excluding ectopic pregnancy was ÂŁ197K for the hospital stated, and was estimated to be ÂŁ1,364K for Scotland overall. Using a theoretical diagnostic serum biomarker we calculated that we could save health services up to ÂŁ976K (lowest saving ÂŁ251K after subanalyses) every year in Scotland. CONCLUSIONS: Ectopic pregnancy is expensive to diagnose and exclude, and the investigation process is often long and might involve significant psychological morbidity. The development of a single diagnostic serum biomarker would minimise this morbidity and lead to significant savings of up to ÂŁ1 million pounds per year in Scotland

    Transport properties of strongly correlated metals:a dynamical mean-field approach

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    The temperature dependence of the transport properties of the metallic phase of a frustrated Hubbard model on the hypercubic lattice at half-filling are calculated. Dynamical mean-field theory, which maps the Hubbard model onto a single impurity Anderson model that is solved self-consistently, and becomes exact in the limit of large dimensionality, is used. As the temperature increases there is a smooth crossover from coherent Fermi liquid excitations at low temperatures to incoherent excitations at high temperatures. This crossover leads to a non-monotonic temperature dependence for the resistance, thermopower, and Hall coefficient, unlike in conventional metals. The resistance smoothly increases from a quadratic temperature dependence at low temperatures to large values which can exceed the Mott-Ioffe-Regel value, hbar a/e^2 (where "a" is a lattice constant) associated with mean-free paths less than a lattice constant. Further signatures of the thermal destruction of quasiparticle excitations are a peak in the thermopower and the absence of a Drude peak in the optical conductivity. The results presented here are relevant to a wide range of strongly correlated metals, including transition metal oxides, strontium ruthenates, and organic metals.Comment: 19 pages, 9 eps figure
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