4,160 research outputs found
Explorando los Impactos de la RFID en los Procesos de Negocios de una Cadena de Suministro
The main purpose of this exploratory study is to improve our understanding of the potential of RFID technology in the context of selected activities in one specific supply chain in the utility industry. Empirical data was gathered from two closely inter-related firms from three layers of the supply chain. A research approach is proposed where we aim to identify RFID opportunities, build potential scenarios and validate these scenarios through laboratory simulation. Results indicate that the adoption of RFID technology allows i) the development of new business models, ii) the integration of processes, and iii) the reengineering and automation of existing processes, facilitating supply chain integration and B-to-B e-commerce activities
Single-step ambient-air synthesis of graphene from renewable precursors as electrochemical genosensor
©The Author(s) 2017. Thermal chemical vapour deposition techniques for graphene fabrication, while promising, are thus far limited by resource-consuming and energy-intensive principles. In particular, purified gases and extensive vacuum processing are necessary for creating a highly controlled environment, isolated from ambient air, to enable the growth of graphene films. Here we exploit the ambient-air environment to enable the growth of graphene films, without the need for compressed gases. A renewable natural precursor, soybean oil, is transformed into continuous graphene films, composed of single-to-few layers, in a single step. The enabling parameters for controlled synthesis and tailored properties of the graphene film are discussed, and a mechanism for the ambient-air growth is proposed. Furthermore, the functionality of the graphene is demonstrated through direct utilization as an electrode to realize an effective electrochemical genosensor. Our method is applicable to other types of renewable precursors and may open a new avenue for low-cost synthesis of graphene films
Coherent J/ψ photoproduction in ultra-peripheral PbPb collisions at √s_NN = 2.76 TeV with the CMS experiment
The cross section for coherent J/ψ photoproduction accompanied by at least one neutron on one side of the interaction point and no neutron activity on the other side, X_(n)0_(n), is measured with the CMS experiment in ultra-peripheral PbPb collisions at √s_NN = 2.76 TeV. The analysis is based on a data sample corresponding to an integrated luminosity of 159 μb^(−1), collected during the 2011 PbPb run. The J/ψ mesons are reconstructed in the dimuon decay channel, while neutrons are detected using zero degree calorimeters. The measured cross section is dσ^(coh)_(X_(n)0_(n))/dy(J/ψ) = 0.36 ± 0.04 (stat) ± 0.04 (syst) mb in the rapidity interval 1.8 < |y| < 2.3. Using a model for the relative rate of coherent photoproduction processes, this X_(n)0_(n) measurement gives a total coherent photoproduction cross section of dσ^(coh)/dy(J/ψ) = 1.82 ± 0.22 (stat) ± 0.20 (syst) ± 0.19 (theo) mb. The data strongly disfavor the impulse approximation model prediction, indicating that nuclear effects are needed to describe coherent J/ψ photoproduction in γ+Pb interactions. The data are found to be consistent with the leading twist approximation, which includes nuclear gluon shadowing
Search for new physics with the M_(T2) variable in all-jets final states produced in pp collisions at √s = 13 TeV
A search for new physics is performed using events that contain one or more jets, no isolated leptons, and a large transverse momentum imbalance, as measured through the M_(T2) variable, which is an extension of the transverse mass in events with two invisible particles. The results are based on a sample of proton-proton collisions collected at a center-of-mass energy of 13 TeV with the CMS detector at the LHC, and that corresponds to an integrated luminosity of 2.3 fb^(−1). The observed event yields in the data are consistent with predictions for the standard model backgrounds. The results are interpreted using simplified models of supersymmetry and are expressed in terms of limits on the masses of potential new colored particles. Assuming that the lightest neutralino is stable and has a mass less than about 500 GeV, gluino masses up to 1550-1750 GeV are excluded at 95% confidence level, depending on the gluino decay mechanism. For the scenario of direct production of squark-antisquark pairs, top squarks with masses up to 800 GeV are excluded, assuming a 100% branching fraction for the decay to a top quark and neutralino. Similarly, bottom squark masses are excluded up to 880 GeV, and masses of light-flavor squarks are excluded up to 600-1260 GeV, depending on the degree of degeneracy of the squark masses
Measurement of the cross section for electroweak production of Zγin association with two jets and constraints on anomalous quartic gauge couplings in proton–proton collisions at √s = 8 TeV
A measurement is presented of the cross section for the electroweak production of a Z boson and a photon in association with two jets in proton–proton collisions at √s = 8 TeV. The Z bosons are identified through their decays to electron or muon pairs. The measurement is based on data collected with the CMS detector corresponding to an integrated luminosity of 19.7 fb^(−1). The electroweak contribution has a significance of 3.0 standard deviations, and the measured fiducial cross section is 1.86_(−0.75)^(+0.90) (stat)_(−0.26)^(+0.34) (syst)±0.05(lumi) fb, while the summed electroweak and quantum chromodynamic total cross section in the same region is observed to be 5.94_(−1.35)^(+1.53) (stat) _(−0.37)^(+0.43) (syst) ± 0.13(lumi) fb. Both measurements are consistent with the leading-order standard model predictions. Limits on anomalous quartic gauge couplings are set based on the Zγ mass distribution
Search for dark matter produced in association with heavy-flavor quark pairs in proton-proton collisions at √s = 13 TeV
A search is presented for an excess of events with heavy-flavor quark pairs (tt and bb) and a large imbalance in transverse momentum in data from proton–proton collisions at a center-of-mass energy of 13 TeV. The data correspond to an integrated luminosity of 2.2fb^(−1) collected with the CMS detector at the CERN LHC. No deviations are observed with respect to standard model predictions. The results are used in the first interpretation of dark matter production in tt and bb final states in a simplified model. This analysis is also the first to perform a statistical combination of searches for dark matter produced with different heavy-flavor final states. The combination provides exclusions that are stronger than those achieved with individual heavy-flavor final states
Search for new physics in final states with two opposite-sign, same-flavor leptons, jets, and missing transverse momentum in pp collisions at √s = 13 TeV
A search is presented for physics beyond the standard model in final states with two opposite-sign, same-flavor leptons, jets, and missing transverse momentum. The data sample corresponds to an integrated luminosity of 2.3 fb^(−1) of proton-proton collisions at √s=13 TeV collected with the CMS detector at the LHC in 2015. The analysis uses the invariant mass of the lepton pair, searching for a kinematic edge or a resonant-like excess compatible with the Z boson mass. Both search modes use several event categories in order to increase the sensitivity to new physics. These categories are based on the rapidity of the leptons, the multiplicity of jets and b jets, the scalar sum of jet transverse momenta, and missing transverse momentum. The observations in all signal regions are consistent with the expectations from the standard model, and the results are interpreted in the context of simplified models of supersymmetry
Search for narrow resonances in dilepton mass spectra in proton–proton collisions at √s = 13 TeV and combination with 8 TeV data
A search for narrow resonances in dielectron and dimuon invariant mass spectra has been performed using data obtained from proton–proton collisions at √s = 13 TeV collected with the CMS detector. The integrated luminosity for the dielectron sample is 2.7 fb−1 and for the dimuon sample 2.9 fb^(−1). The sensitivity of the search is increased by combining these data with a previously analyzed set of data obtained at √s = 8 TeV and corresponding to a luminosity of 20 fb^(−1). No evidence for non-standard-model physics is found, either in the 13 TeV data set alone, or in the combined data set. Upper limits on the product of production cross section and branching fraction have also been calculated in a model-independent manner to enable interpretation in models predicting a narrow dielectron or dimuon resonance structure. Limits are set on the masses of hypothetical particles that could appear in new-physics scenarios. For the Z_(SSM)^′ particle, which arises in the sequential standard model, and for the superstring inspired Z_ψ^′ particle, 95% confidence level lower mass limits for the combined data sets and combined channels are found to be 3.37 and 2.82 TeV, respectively. The corresponding limits for the lightest Kaluza–Klein graviton arising in the Randall–Sundrum model of extra dimensions with coupling parameters 0.01 and 0.10 are 1.46 and 3.11 TeV, respectively. These results significantly exceed the limits based on the 8 TeV LHC data
Measurement of the B^± Meson Nuclear Modification Factor in Pb-Pb Collisions at √S_(NN) = 5.02  TeV
The differential production cross sections of B^± mesons are measured via the exclusive decay channels B^± → J/ψK^ ±→ μ^+μ^−K^± as a function of transverse momentum in pp and Pb-Pb collisions at a center-of-mass energy √S_(NN) = 5.02  TeV per nucleon pair with the CMS detector at the LHC. The pp(Pb-Pb) data set used for this analysis corresponds to an integrated luminosity of 28.0  pb^(-1) (351  μb^(-1)). The measurement is performed in the B^± meson transverse momentum range of 7 to 50  GeV/c, in the rapidity interval |y| < 2.4. In this kinematic range, a strong suppression of the production cross section by about a factor of 2 is observed in the Pb-Pb system in comparison to the expectation from pp reference data. These results are found to be roughly compatible with theoretical calculations incorporating beauty quark diffusion and energy loss in a quark-gluon plasma
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