3,333 research outputs found

    Tailoring block copolymer nanoporous thin films with acetic acid as a small guest molecule

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    Block copolymers offer the fabrication of mesoporous thin films with distinct nanoscale structural features. In this contribution, we present the use of acetic acid (CH3COOH) as a low‐molecular‐weight guest molecule to tune the supramolecular assembly of poly[styrene‐block‐(4‐vinylpyridine)] (PS‐b‐P4VP), offering a versatile and straightforward method to obtain tailored nanostructured films with controlled topography and pore size. Spin‐coating toluene solutions of PS‐b‐P4VP, with a variable amount of CH3COOH, leads to micellar thin films, where the micelles contain the carboxylic acid as a guest molecule. The size can be conveniently modified in these films (from 48 to 75 nm) by varying the amount of organic acid in the starting solutions. Subsequent surface reconstruction of micellar films using ethanol leads to ring‐shaped copolymer nanoporous films with modulated diameter. Controlling the micelle reconstruction process, cylindrical porous films are also obtained. Interestingly, changing the type of aliphatic carboxylic acid leads to a modification of the observed film morphology from micelles to out‐of‐plane P4VP cylinders (or lamellae) in a PS matrix

    Charm Production in DPMJET

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    In this work, charm production in the {\sc dpmjet} hadronic jet simulation is compared to experimental data. Since the major application of {\sc dpmjet} is the simulation of cosmic ray-induced air showers, the version of the code integrated in the CORSIKA simulation package has been used for the comparison. Wherever necessary, adjustments have been made to improve agreement between simulation and data. With the availability of new muon/neutrino detectors that combine a large fiducial volume with large amounts of shielding, investigation of prompt muons and neutrinos from cosmic ray interactions will be feasible for the first time. Furthermore, above 100\gtrsim 100 TeV charmed particle decay becomes the dominant background for diffuse extraterrestrial neutrino flux searches. A reliable method to simulate charm production in high-energy proton-nucleon interactions is therefore required.Comment: 10 pages, to be published in JCA

    CSA06 Computing, Software and Analysis challenge at the Spanish Tier-1 and Tier-2 sites

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    This note describes the participation of the Spanish centres PIC, CIEMAT and IFCA as Tier-1 and Tier-2 sites in the CMS CSA06 Computing, Software and Analysis challenge. A number of the facilities, services and workflows have been demonstrated at the 2008 25% scale. Very valuable experience has been gained running the complex computing system under realistic conditions at a significant scale. The focus of this note is on presenting achieved results, operational experience and lessons learnt during the challenge

    Factors associated with the development of septic shock in patients with candidemia: A post hoc analysis from two prospective cohorts

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    Background: Almost one third of the patients with candidemia develop septic shock. The understanding why some patients do and others do not develop septic shock is very limited. The objective of this study was to identify variables associated with septic shock development in a large population of patients with candidemia. Methods: A post hoc analysis was performed on two prospective, multicenter cohort of patients with candidemia from 12 hospitals in Spain and Italy. All episodes occurring from September 2016 to February 2018 were analyzed to assess variables associated with septic shock development defined according to The Third International Consensus Definition for Sepsis and Septic Shock (Sepsis-3). Results: Of 317 candidemic patients, 99 (31.2%) presented septic shock attributable to candidemia. Multivariate logistic regression analysis identifies the following factors associated with septic shock development: age > 50 years (OR 2.57, 95% CI 1.03-6.41, p = 0.04), abdominal source of the infection (OR 2.18, 95% CI 1.04-4.55, p = 0.04), and admission to a general ward at the time of candidemia onset (OR 0.21, 95% CI, 0.12-0.44, p = 0.001). Septic shock development was independently associated with a greater risk of 30-day mortality (OR 2.14, 95% CI 1.08-4.24, p = 0.02). Conclusions: Age and abdominal source of the infection are the most important factors significantly associated with the development of septic shock in patients with candidemia. Our findings suggest that host factors and source of the infection may be more important for development of septic shock than intrinsic virulence factors of organisms

    TESLA Technical Design Report Part III: Physics at an e+e- Linear Collider

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    The TESLA Technical Design Report Part III: Physics at an e+e- Linear ColliderComment: 192 pages, 131 figures. Some figures have reduced quality. Full quality figures can be obtained from http://tesla.desy.de/tdr. Editors - R.-D. Heuer, D.J. Miller, F. Richard, P.M. Zerwa

    Search for the glueball candidates f0(1500) and fJ(1710) in gamma gamma collisions

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    Data taken with the ALEPH detector at LEP1 have been used to search for gamma gamma production of the glueball candidates f0(1500) and fJ(1710) via their decay to pi+pi-. No signal is observed and upper limits to the product of gamma gamma width and pi+pi- branching ratio of the f0(1500) and the fJ(1710) have been measured to be Gamma_(gamma gamma -> f0(1500)). BR(f0(1500)->pi+pi-) < 0.31 keV and Gamma_(gamma gamma -> fJ(1710)). BR(fJ(1710)->pi+pi-) < 0.55 keV at 95% confidence level.Comment: 10 pages, 3 figure

    The Hubbard model within the equations of motion approach

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    The Hubbard model has a special role in Condensed Matter Theory as it is considered as the simplest Hamiltonian model one can write in order to describe anomalous physical properties of some class of real materials. Unfortunately, this model is not exactly solved except for some limits and therefore one should resort to analytical methods, like the Equations of Motion Approach, or to numerical techniques in order to attain a description of its relevant features in the whole range of physical parameters (interaction, filling and temperature). In this manuscript, the Composite Operator Method, which exploits the above mentioned analytical technique, is presented and systematically applied in order to get information about the behavior of all relevant properties of the model (local, thermodynamic, single- and two- particle ones) in comparison with many other analytical techniques, the above cited known limits and numerical simulations. Within this approach, the Hubbard model is shown to be also capable to describe some anomalous behaviors of the cuprate superconductors.Comment: 232 pages, more than 300 figures, more than 500 reference

    Search for supersymmetry with a dominant R-parity violating LQDbar couplings in e+e- collisions at centre-of-mass energies of 130GeV to 172 GeV

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    A search for pair-production of supersymmetric particles under the assumption that R-parity is violated via a dominant LQDbar coupling has been performed using the data collected by ALEPH at centre-of-mass energies of 130-172 GeV. The observed candidate events in the data are in agreement with the Standard Model expectation. This result is translated into lower limits on the masses of charginos, neutralinos, sleptons, sneutrinos and squarks. For instance, for m_0=500 GeV/c^2 and tan(beta)=sqrt(2) charginos with masses smaller than 81 GeV/c^2 and neutralinos with masses smaller than 29 GeV/c^2 are excluded at the 95% confidence level for any generation structure of the LQDbar coupling.Comment: 32 pages, 30 figure

    Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

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    A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

    Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

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    The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30
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