767 research outputs found

    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

    How Managers Can Predict Customer Retention Rates Through Psychological Profiling.

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    Managers have become increasingly concerned with the retention of their customers and how they improve their retention rates. Customer Relationship Management (CRM) processes have been implemented to allow managers to profile their customers in terms of their value and risk of defection, and to target customers differently. However, customer profiling is often based solely on customers’ behaviours e.g. level/ type of product consumption or demographic characteristics e.g. age, sex, length of customer relationship. Using my own research within the fitness industry, this paper will highlight the psychological variables which have been measured e.g. satisfaction, brand identification and self-determination and how they can be used to predict intentions to, and defection from, an organisation

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

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    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

    Measurement of D*+/- meson production in jets from pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    This paper reports a measurement of D*+/- meson production in jets from proton-proton collisions at a center-of-mass energy of sqrt(s) = 7 TeV at the CERN Large Hadron Collider. The measurement is based on a data sample recorded with the ATLAS detector with an integrated luminosity of 0.30 pb^-1 for jets with transverse momentum between 25 and 70 GeV in the pseudorapidity range |eta| < 2.5. D*+/- mesons found in jets are fully reconstructed in the decay chain: D*+ -> D0pi+, D0 -> K-pi+, and its charge conjugate. The production rate is found to be N(D*+/-)/N(jet) = 0.025 +/- 0.001(stat.) +/- 0.004(syst.) for D*+/- mesons that carry a fraction z of the jet momentum in the range 0.3 < z < 1. Monte Carlo predictions fail to describe the data at small values of z, and this is most marked at low jet transverse momentum.Comment: 10 pages plus author list (22 pages total), 5 figures, 1 table, matches published version in Physical Review

    Sedimentology, stratigraphic context, and implications of Miocene intrashelf bottomset deposits, offshore New Jersey

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    Drilling of intrashelf Miocene clinothems onshore and offshore New Jersey has provided better understanding of their topset and foreset deposits, but the sedimentology and stratigraphy of their bottomset deposits have not been documented in detail. Three coreholes (Sites M27–M29), collected during Integrated Ocean Drilling Program (IODP) Expedition 313, intersect multiple bottomset deposits, and their analysis helps to refine sequence stratigraphic interpretations and process response models for intrashelf clinothems. At Site M29, the most downdip location, chronostratigraphically well-constrained bottomset deposits follow a repeated stratigraphic motif. Coarse-grained glauconitic quartz sand packages abruptly overlie deeply burrowed surfaces. Typically, these packages coarsen then fine upwards and pass upward into bioturbated siltstones. These coarse sand beds are amalgamated and poorly sorted and contain thin-walled shells, benthic foraminifera, and extrabasinal clasts, consistent with an interpretation of debrites. The sedimentology and mounded seismic character of these packages support interpretation as debrite-dominated lobe complexes. Farther updip, at Site M28, the same chronostratigraphic units are amalgamated, with the absence of bioturbated silts pointing to more erosion in proximal locations. Graded sandstones and dune-scale cross-bedding in the younger sequences in Site M28 indicate deposition from turbidity currents and channelization. The sharp base of each package is interpreted as a sequence boundary, with a period of erosion and sediment bypass evidenced by the burrowed surface, and the coarse-grained debritic and turbiditic deposits representing the lowstand systems tract. The overlying fine-grained deposits are interpreted as the combined transgressive and highstand systems tract deposits and contain the deepwater equivalent of the maximum flooding surface. The variety in thickness and grain-size trends in the coarse-grained bottomset packages point to an autogenic control, through compensational stacking of lobes and lobe complexes. However, the large-scale stratigraphic organization of the bottomset deposits and the coarse-grained immature extrabasinal and reworked glauconitic detritus point to external controls, likely a combination of relative sea-level fall and waxing-and-waning cycles of sediment supply. This study demonstrates that large amounts of sediment gravity-flow deposits can be generated in relatively shallow (~100–200 m deep) and low-gradient (~1°–4°) clinothems that prograded across a deep continental shelf. This physiography likely led to the dominance of debris flow deposits due to the short transport distance limiting transformation to low-concentration turbidity currents

    Search for supersymmetry in final states with jets, missing transverse momentum and one isolated lepton in sqrt{s} = 7 TeV pp collisions using 1 fb-1 of ATLAS data

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    We present an update of a search for supersymmetry in final states containing jets, missing transverse momentum, and one isolated electron or muon, using 1.04 fb^-1 of proton-proton collision data at sqrt{s} = 7 TeV recorded by the ATLAS experiment at the LHC in the first half of 2011. The analysis is carried out in four distinct signal regions with either three or four jets and variations on the (missing) transverse momentum cuts, resulting in optimized limits for various supersymmetry models. No excess above the standard model background expectation is observed. Limits are set on the visible cross-section of new physics within the kinematic requirements of the search. The results are interpreted as limits on the parameters of the minimal supergravity framework, limits on cross-sections of simplified models with specific squark and gluino decay modes, and limits on parameters of a model with bilinear R-parity violation.Comment: 18 pages plus author list (30 pages total), 9 figures, 4 tables, final version to appear in Physical Review

    Teaching of Energy Issues: A debate proposal for a GLobal Reorientation

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    The growing awareness of serious difficulties in the learning of energy issues has produced a great deal of research, most of which is focused on specific conceptual aspects. In our opinion, the difficulties pointed out in the literature are interrelated and connected to other aspects (conceptual as well as procedural and axiological), which are not sufficiently taken into account in previous research. This paper aims to carry out a global analysis in order to avoid the more limited approaches that deal only with individual aspects. From this global analysis we have outlined 24 propositions that are put forward for debate to lay the foundations for a profound reorientation of the teaching of energy topics in upper high school courses, in order to facilitate a better scientific understanding of these topics, avoid many students' misconceptions and enhance awareness of the current situation of planetary emergency

    Reducing heterotic M-theory to five dimensional supergravity on a manifold with boundary

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    This paper constructs the reduction of heterotic MM-theory in eleven dimensions to a supergravity model on a manifold with boundary in five dimensions using a Calabi-Yau three-fold. New results are presented for the boundary terms in the action and for the boundary conditions on the bulk fields. Some general features of dualisation on a manifold with boundary are used to explain the origin of some topological terms in the action. The effect of gaugino condensation on the fermion boundary conditions leads to a `twist' in the chirality of the gravitino which can provide an uplifting mechanism in the vacuum energy to cancel the cosmological constant after moduli stabilisation.Comment: 16 pages, RevTe

    Measurement of tau polarization in W->taunu decays with the ATLAS detector in pp collisions at sqrt(s) = 7 TeV

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    In this paper, a measurement of tau polarization in W->taunu decays is presented. It is measured from the energies of the decay products in hadronic tau decays with a single final state charged particle. The data, corresponding to an integrated luminosity of 24 pb^-1, were collected by the ATLAS experiment at the Large Hadron Collider in 2010. The measured value of the tau polarization is Ptau = -1.06 +/- 0.04 (stat) + 0.05 (syst) - 0.07 (syst), in agreement with the Standard Model prediction, and is consistent with a physically allowed 95% CL interval [-1,-0.91]. Measurements of tau polarization have not previously been made at hadron colliders.Comment: 10 pages plus author list (25 pages total), 4 figures, 4 tables, revised author list, matches published EPJC versio

    Site-Specific Iron Substitution in STA-28, a Large Pore Aluminophosphate Zeotype Prepared by Using 1, 10-Phenanthrolines as Framework-Bound Templates

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    An AlPO4 zeotype has been prepared using the aromatic diamine 1, 10-phenanthroline and some of its methylated analogues as templates. In each case the two template N atoms bind to a specific framework Al site to expand its coordination to the unusual octahedral AlO4N2 environment. Furthermore, using this framework-bound template, Fe atoms can be included selectively at this site in the framework by direct synthesis, as confirmed by annular dark field scanning transmission electron microscopy and Rietveld refinement. Calcination removes the organic molecules to give large pore framework solids, with BET surface areas up to 540 m2 g-1 and two perpendicular sets of channels that intersect to give pore space connected by 12-ring openings along all crystallographic directions
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