19 research outputs found

    Modelling Rhizophora Mangle L Bark-Extract Effects on Concrete Steel-Rebar in 0.5 M H2SO4: Implications on Concentration for Effective Corrosion-Inhibition

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    In this paper, electrochemical test-data were obtained from 0.5 M H2SO4-immersed steel-reinforced concrete admixed with different Rhizophora mangle L bark-extract concentrations and subjected to modelling analyses for studying corrosion-inhibition effectiveness. For this, macrocell current from zero-resistance ammeter and corrosion-rate from linear-polarization resistance instruments were respectively subjected to total-corrosion modelling as per ASTM G109-99a and statistical-distribution modelling as per ASTM G16-95 R04. Further analyses of these modelled test-results showed that the corrosion-rate correlated excellently (R = 95.04%, Nash-Sutcliffe efficiency = 90.33%, p-value = 0.037) with function of the bark-extract concentration and the total-corrosion from the steel-reinforced concrete samples. In agreements, both experimental and correlation fitting models identified 0.167% Rhizophora mangle L bark-extract with good corrosion-inhibition efficiency, η = 73.30% (experimental) or η = 60.81% (correlation prediction). These bare implications on macrocell technique usage for complimenting identification of admixture concentration for effective corrosion-inhibition of concrete steel-rebar in the microbial/industrial simulating-environment studied

    Cysticercose of the central nervous system: II. Spinal cysticercose

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    The compromising of the spinal canal by cysticercus is considered infrequent, varying from 16 to 20% in relation to the brain involvement. In the spinal canal the cysticercus predominantly places in the subarachnoid space. Clinical signs in spinal cysticercosis can be caused by direct compression of the spinal cord/roots by cisticerci and by local or at distance inflammatory reactions (arachnoiditis). Another mechanism of lesion is degeneration of the spinal cord due to pachymeningitis or circulatory insufficiency. The most frequent clinical features are signs of spinal cord and/or cauda equina compression. The diagnosis of spinal cysticercosis is based on evidence of cerebral cysticercosis and on neuroradiological examinations (myelography and myelo-CT) that show signs of arachnoiditis and images of cysts in the subarachnoid space and sometimes, signs of intramedullary lesions, but the confirmation can only be made through immunological reactions in the CSF or during surgery. The clinical course of 10 patients with diagnosis of spinal cysticercosis observed among 182 patients submitted to surgical treatment due to this diasease are analyzed. The clinical pictures in all cases were signs of spinal cord or roots compression. All but two presented previously signs of brain cysticercosis. Neuroradiological examinations showed signs of arachnoiditis in 4 patients, images of cysts in the subarachnoid space in 5, and signs of arachnoiditis and images of cysts in one. The 6 patients that presented intraspinal cysts were submitted to exeresis of the cysts and 2 patients with total blockage of the spinal canal underwent surgery for diagnosis. The 2 remaining patients with arachnoiditis and blockge of the spinal canal were clinically treated. All of the six patients submitted to cyst exeresis had initial improvement but 4 of them later developed arachnoiditis and recurrence of the clinical signs and only 2 remained well for long-term. The 2 non operated patients had no improvement of their clinical signs. Two patients died later due to complications of cerebral cysticercosis. Based on the experience acquired in the management of these patients we indicate surgical treatment for patients that present free cyst in subarachnoid space. For those who present arachnoiditis, surgery is indicated only when there is doubt in the diagnosis. Intramedullary cysts should also be surgically treated

    Performance of the CMS missing transverse momentum reconstruction in pp data at √s= 8 TeV

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    The performance of missing transverse energy reconstruction algorithms is presented using root s = 8 TeV proton-proton (pp) data collected with the CMS detector. Events with anomalous missing transverse energy are studied, and the performance of algorithms used to identify and remove these events is presented. The scale and resolution for missing transverse energy, including the effects of multiple pp interactions (pileup), are measured using events with an identified Z boson or isolated photon, and are found to be well described by the simulation. Novel missing transverse energy reconstruction algorithms developed specifically to mitigate the effects of large numbers of pileup interactions on the missing transverse energy resolution are presented. These algorithms significantly reduce the dependence of the missing transverse energy resolution on pileup interactions. Finally, an algorithm that provides an estimate of the significance of the missing transverse energy is presented, which is used to estimate the compatibility of the reconstructed missing transverse energy with a zero nominal value

    Search for pair production of third-generation scalar leptoquarks and top squarks in proton-proton collisions at v root s=8 TeV

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    A search for pair production of third-generation scalar leptoquarks and supersymmetric top quark partners, top squarks, in final states involving tau leptons and bottom quarks is presented. The search uses events from a data sample of proton-proton collisions corresponding to an integrated luminosity of 19.7 fb(-1), collected with the CMS detector at the LHC with root s = 8 TeV. The number of observed events is found to be in agreement with the expected standard model background. Third-generation scalar leptoquarks with masses below 740 GeV are excluded at 95% confidence level, assuming a 100% branching fraction for the leptoquark decay to a tau lepton and a bottom quark. In addition, this mass limit applies directly to top squarks decaying via an R-parity violating coupling. lambda(') (333). The search also considers a similar signature from top squarks undergoing a chargino-mediated decay involving the Rparity violating coupling. lambda(')(3jk). Each top squark decays to a tau lepton, a bottom quark, and two light quarks. Top squarks in this model with masses below 580 GeV are excluded at 95% confidence level. The constraint on the leptoquark mass is the most stringent to date, and this is the first search for top squarks decaying via. lambda(')(3jk)

    Measurement of the cross section ratio sigma(t(t)over-barb(b)over-bar)/sigma(t(t)over-barjj) in pp collisions at root s=8 TeV

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    The first measurement of the cross section ratio sigma(t (t) over barb (b) over bar)/sigma(t (t) over bar jj) is presented using a data sample corresponding to an integrated luminosity of 19.6 fb(-1) collected in pp collisions at root s = 8 TeV with the CMS detector at the LHC. Events with two leptons (e or mu) and four reconstructed jets, including two identified as b quark jets, in the final state are selected. The ratio is determined for a minimum jet transverse momentum p(T) of both 20 and 40 GeV/c. The measured ratio is 0.022 +/- 0.003 (stat) +/- 0.005 (syst) for p(T) > 20GeV/c. The absolute cross sections sigma(t (t) over barb (b) over bar) and sigma(t (t) over bar jj) are also measured. The measured ratio for p(T) > 40 GeV/c is compatible with a theoretical quantum chromodynamics calculation at next-to-leading order. (C) 2015 CERN for the benefit of the CMS Collaboration

    Search for supersymmetry in pp collisions at in events with a single lepton, large jet multiplicity, and multiple b jets

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    Results are reported from a search for supersymmetry in pp collisions at a center-of-mass energy of 8 TeV, based on events with a single isolated lepton (electron or muon) and multiple jets, at least two of which are identified as b jets. The data sample corresponds to an integrated luminosity of 19.3 fb(-1) recorded by the CMS experiment at the LHC in 2012. The search is motivated by supersymmetric models that involve strong-production processes and cascade decays of new particles. The resulting final states contain multiple jets as well as missing transverse momentum from weakly interacting particles. The event yields, observed across several kinematic regions, are consistent with the expectations from standard model processes. The results are interpreted in the context of simplified supersymmetric scenarios with pair production of gluinos, where each gluino decays to a top quark-antiquark pair and the lightest neutralino. For the case of decays via virtual top squarks, gluinos with a mass smaller than 1.26 TeV are excluded for low neutralino masses

    Measurement of the t(t)over-bar production cross section in pp collisions at root s=8 TeV in dilepton final states containing one tau lepton

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    The top-quark pair production cross section is measured in final states with one electron or muon and one hadronically decaying tau lepton from the process t (t) over bar -> (l nu(l))(tau nu(tau))b (b) over bar, where l = e, mu. The data sample corresponds to an integrated luminosity of 19.6 fb(-1) collected with the CMS detector in proton-proton collisions at root s = 8 TeV. The measured cross section sigma(t (t) over bar) = 257 +/- 3 (stat) +/- 24 (syst) +/- 7 (lumi) pb, assuming a top-quark mass of 172.5 GeV, is consistent with the standard model prediction

    Measurement of the production cross section ratio sigma(chi b2(1P))/sigma(chi b1(1P)) in pp collisions at root s=8TeV

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    A measurement of the production cross section ratio sigma(chi b2(1P))/sigma(chi b1(1P)) is presented. The chi b1 (1P) and chi b2 (1P) bottomonium states, promptly produced in pp collisions at root s = 8TeV, are detected by the CMS experiment at the CERN LHC through their radiative decays chi b1,2(1P) -> Y(1S) + gamma. The emitted photons are measured through their conversion to e(+) e(-) pairs, whose reconstruction allows the two states to be resolved. The Y(1S) is measured through its decay to two muons. An event sample corresponding to an integrated luminosity of 20.7 fb(-1) is used to measure the cross section ratio in a phase-space region defined by the photon pseudorapidity, vertical bar eta(gamma)vertical bar < 1.0; the Y(1S) rapidity, vertical bar y(Y)vertical bar < 1.5; and the Y(1S) transverse momentum, 7 < p(T)(Y) < 40 GeV. The cross section ratio shows no significant dependence on the.(1S) transverse momentum, with a measured average value of 0.85 +/- 0.07 (stat + syst) +/- 0.08 (BF), where the first uncertainty is the combination of the experimental statistical and systematic uncertainties and the second is from the uncertainty in the ratio of the chi b branching fractions

    Measurement of the production cross section for a W boson and two b jets in pp collisions at root s=7 TeV

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    The production cross section for a Wboson and two b jets is measured using proton-proton collisions at v root s = 7 TeV in a data sample collected with the CMS experiment at the LHC corresponding to an integrated luminosity of 5.0 fb(-1). The W + bbevents are selected in the W..decay mode by requiring a muon with transverse momentum pT> 25GeVand pseudorapidity |eta| 25GeVand |eta| < 2.4. The measured W + bbproduction cross section in the fiducial region, calculated at the level of final-state particles, is s(pp. W + bb) xB(W..) = 0.53 +/- 0.05 (stat.) +/- 0.09 (syst.) +/- 0.06 (theo.) 0.01 (lum.) pb, in agreement with the standard model prediction. In addition, kinematic distributions of the W + bbsystem are in agreement with the predictions of a simulation usingMadGraphandpythia
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