Aplicabilidad de la energía cinética como parámetro indicador del inicio de la inestabilidad en materiales granulares en un tambor rotador empleando la técnica PIV (Particle Image Velocimetry)

Se presenta un estudio del comportamiento de materiales granulares sometidos a procesos de inestabilidad. Determinadas granulometrías se ensayan en diferentes montajes, para la captura de imágenes consecutivas del proceso de flujo de los materiales presentes en el tambor rotador. El procesamiento de las imágenes es realizado mediante la técnica de Particle Image Velocimetry (PIV) para así poder determinar los vectores de desplazamiento y el campo de velocidad de las partículas, utilizando el toolbox de Matlab llamado Pivlab. Posteriormente se calcula la energía cinética y se determina su aplicabilidad mediante el análisis de la variación de este parámetro en los procesos de inestabilidad y su relación con las granulometrías de los materiales y las velocidades de rotación del tambor.A study of the behavior of materials under granular instability processes is presented. Determinates particle sizes tested in different assemblies, to capture consecutive images of the process flow of the materials present in the rotator drum. The image processing is performed by the technique of Particle Image Velocimetry (PIV) in order to determine the displacement vectors and particle velocity field, using the Matlab toolbox called Pivlab. Subsequently kinetic energy is calculated and its applicability is determined by analyzing oscillation of this parameter on instability processes and its relationship with the grain sizes of materials and speeds of rotation of the drum.Ingeniero (a) CivilPregrad

Aplicabilidad de la energía cinética en el inicio de la inestabilidad de materiales granulares en un tambor rotador mediante la técnica PIV (Particle Image Velocimetry)

This article presents a study of the behavior of granular materials that are subject to a process of instability in a rotating drum. By employing an original procedure, the applicability of kinetic energy as a parameter to measure processes of instability and their relationships with the granulometry of materials and rotating drum’s velocities are evaluated. Certain granulometries are tested in various set-ups in order to capture consecutive images of the process in which the present materials flow into the rotating drum. Image processing is carried out by using the Particle Image Velocimetry (PIV) technique in order to be able to determine the particles’ displacement vectors and velocity fields by using Pivlab, the Matlab toolbox. Subsequently, the kinetic energy is calculated and its applicability is determined through analyzing the variation of this parameter in the processes of instability and its relationship with the granulometry of materials and the velocities of the rotating drum. The trials undertaken as part of this study have determined that there are two types of particle flow: falling and rolling. Moreover, the dependence of the material type on the threshold value of kinetic energy at the beginning of the process of instability was discovered as well as the independence of this parameter from the angle of inclination of the material inside the rotating drum. The results from this research allow for an analysis of the processes of instability in granular materials by means of non-conventional methodologiesSe presenta un estudio del comportamiento de materiales granulares sometidos a procesos de inestabilidad en un tambor rotador. Mediante un procedimiento novedoso se evalúa la aplicabilidad de la energía cinética como parámetro de medición de procesos de inestabilidad y su relación con las granulometrías de los materiales y las velocidades de rotación del tambor. Determinadas granulometrías se ensayan en diferentes montajes, para la captura de imágenes consecutivas del proceso de flujo de los materiales presentes en el tambor rotador. El procesamiento de las imágenes es realizado mediante la técnica de Particle Image Velocimetry (PIV) para así poder determinar los vectores de desplazamiento y el campo de velocidad de las partículas, utilizando el toolbox de Matlab llamado Pivlab. Posteriormente se calcula la energía cinética y se determina su aplicabilidad mediante el análisis de la variación de este parámetro en los procesos de inestabilidad y su relación con las granulometrías de los materiales y las velocidades de rotación del tambor. En los ensayos realizados se determinaron dos tipos de flujo de partículas: régimen de caída y régimen rodante. Además, se encontró la dependencia del tipo de material en el valor umbral de energía cinética al inicio del proceso de inestabilidad y la independencia de este parámetro del ángulo de inclinación del material dentro del tambor rotador. Los resultados de este proyecto permiten un análisis de los procesos de inestabilidad en materiales granulares mediante metodologías no convencionales

Perspectivas de innovación en gestión, educación ambiental para la adaptación y la mitigación

Esta publicación del libro-foro sobre ciudad y cambio climático responde al aporte de los diferentes profesionales de las entidades públicas y privadas que participaron en calidad de conferencistas, ponentes, panelistas y expositores y compartieron sus experiencias en la ciudad como una contribución al conocimiento de las comunidades acerca de la creciente importancia y consideración de la adaptación y mitigación. Se consideraron acciones de políticas públicas por parte de las administraciones públicas, los sectores económicos y la sociedad, grupos ecológicos y fundaciones ecológicas y de igual forma las acciones y grandes esfuerzos realizados por el Ministerio del Ambiente, el IDEAM, la CAR, la Secretaría de Ambiente, el Jardín Botánico, la Red RAUS y de los grupos de investigación de las universidades

Measurement of the top quark mass using charged particles in pp collisions at root s=8 TeV

Peer reviewe

Bose-Einstein correlations of charged hadrons in proton-proton collisions at s\sqrt s = 13 TeV

Bose-Einstein correlations of charged hadrons are measured over a broad multiplicity range, from a few particles up to about 250 reconstructed charged hadrons in proton-proton collisions at $\sqrt{s}$ = 13 TeV. The results are based on data collected using the CMS detector at the LHC during runs with a special low-pileup configuration. Three analysis techniques with different degrees of dependence on simulations are used to remove the non-Bose-Einstein background from the correlation functions. All three methods give consistent results. The measured lengths of homogeneity are studied as functions of particle multiplicity as well as average pair transverse momentum and mass. The results are compared with data from both CMS and ATLAS at $\sqrt{s}$ = 7 TeV, as well as with theoretical predictions.[graphic not available: see fulltext]Bose-Einstein correlations of charged hadrons are measured over a broad multiplicity range, from a few particles up to about 250 reconstructed charged hadrons in proton-proton collisions at $\sqrt{s} =$ 13 TeV. The results are based on data collected using the CMS detector at the LHC during runs with a special low-pileup configuration. Three analysis techniques with different degrees of dependence on simulations are used to remove the non-Bose-Einstein background from the correlation functions. All three methods give consistent results. The measured lengths of homogeneity are studied as functions of particle multiplicity as well as average pair transverse momentum and mass. The results are compared with data from both CMS and ATLAS at $\sqrt{s} =$ 7 TeV, as well as with theoretical predictions

Search for dark matter in events with a leptoquark and missing transverse momentum in proton-proton collisions at 13 TeV

A search is presented for dark matter in proton-proton collisions at a center-of-mass energy of root s= 13 TeV using events with at least one high transverse momentum (p(T)) muon, at least one high-p(T) jet, and large missing transverse momentum. The data were collected with the CMS detector at the CERN LHC in 2016 and 2017, and correspond to an integrated luminosity of 77.4 fb(-1). In the examined scenario, a pair of scalar leptoquarks is assumed to be produced. One leptoquark decays to a muon and a jet while the other decays to dark matter and low-p(T) standard model particles. The signature for signal events would be significant missing transverse momentum from the dark matter in conjunction with a peak at the leptoquark mass in the invariant mass distribution of the highest p(T) muon and jet. The data are observed to be consistent with the background predicted by the standard model. For the first benchmark scenario considered, dark matter masses up to 500 GeV are excluded for leptoquark masses m(LQ) approximate to 1400 GeV, and up to 300 GeV for m(LQ) approximate to 1500 GeV. For the second benchmark scenario, dark matter masses up to 600 GeV are excluded for m(LQ) approximate to 1400 GeV. (C) 2019 The Author(s). Published by Elsevier B.V.Peer reviewe

Search for an L-mu - L-tau gauge boson using Z -> 4 mu events in proton-proton collisions at root s=13 TeV

A search for a narrow Z' gauge boson with a mass between 5 and 70 GeV resulting from an L-mu - L-tau U (1) local gauge symmetry is reported. Theories that predict such a particle have been proposed as an explanation of various experimental discrepancies, including the lack of a dark matter signal in direct-detection experiments, tension in the measurement of the anomalous magnetic moment of the muon, and reports of possible lepton flavor universality violation in B meson decays. A data sample of proton-proton collisions at a center-of-mass energy of 13 TeV is used, corresponding to an integrated luminosity of 77.3 fb(-1) recorded in 2016 and 2017 by the CMS detector at the LHC. Events containing four muons with an invariant mass near the standard model Z boson mass are analyzed, and the selection is further optimized to be sensitive to the events that may contain Z -> Z'mu mu -> 4 mu decays. The event yields are consistent with the standard model predictions. Upper limits of 10(-8)-10(-7) at 95% confidence level are set on the product of branching fractions B(Z -> Z'mu mu)B(Z' -> mu mu), depending on the Z' mass, which excludes a Z' boson coupling strength to muons above 0.004-0.3. These are the first dedicated limits on L-mu - L-tau models at the LHC and result in a significant increase in the excluded model parameter space. The results of this search may also be used to constrain the coupling strength of any light Z' gauge boson to muons. (C) 2019 The Author(s). Published by Elsevier B.V.Peer reviewe

Measurement of electroweak WZ boson production and search for new physics in WZ + two jets events in pp collisions at √s=13TeV

A measurement of WZ electroweak (EW) vector boson scattering is presented. The measurement is performed in the leptonic decay modes WZ→ℓνℓ′ℓ′, where ℓ,ℓ′=e,μ. The analysis is based on a data sample of proton-proton collisions at √s=13 TeV at the LHC collected with the CMS detector and corresponding to an integrated luminosity of 35.9 fb−1. The WZ plus two jet production cross section is measured in fiducial regions with enhanced contributions from EW production and found to be consistent with standard model predictions. The EW WZ production in association with two jets is measured with an observed (expected) significance of 2.2 (2.5) standard deviations. Constraints on charged Higgs boson production and on anomalous quartic gauge couplings in terms of dimension-eight effective field theory operators are also presented

Studies of Beauty Suppression via Nonprompt D-0 Mesons in Pb-Pb Collisions at root s(NN)=5.02 TeV

The transverse momentum spectra of D-0 mesons from b hadron decays are measured at midrapidity (vertical bar y vertical bar D-0 yield is found to be suppressed in the measured p(T) range from 2 to 100 GeV/c as compared to pp collisions. The suppression is weaker than that of prompt D-0 mesons and charged hadrons for p(T) around 10 GeV/c. While theoretical calculations incorporating partonic energy loss in the quark-gluon plasma can successfully describe the measured B -> D-0 suppression at higher p(T), the data show an indication of larger suppression than the model predictions in the range of 2 <p(T) <5 GeV/c.Peer reviewe

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p&lt;0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p&lt;0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised