Cu(II) adsorption from aqueous solutions using the inner and outer portions of sugarcane bagasse

Artículo publicado en revista indizadaIn the present work, the adsorption capacity of internal and external portions of treated sugarcane bagasse (SCB) to remove Cu(II) from aqueous solution was evaluated. In order to reuse this solid waste as an effective adsorption material, both portions were treated with three different solutions (hot water, ethanol and NaOH) to remove sugar, external gummy tissue and impurities. Adsorption experiments were carried out in a batch system at room temperature. The kinetic data were fitted to pseudo-second order and Elovich models for the internal portion, and to the Elovich model for the external portion reaching equilibrium times from 8 to 24 h. Freundlich and Langmuir–Freundlich models described well the adsorption behavior of all systems. The compositional differences of the two portions of SCB and the surface chemistry were analyzed. Material characterization by scanning electron microscopy, Fourier transformed infrared spectroscopy, and X-ray photoelectron spectroscopy demonstrated morphologic and chemical modifications of the material after each treatment. Results showed that external SCB treated with a sodium hydroxide solution and internal SCB treated with ethanol solution were the best adsorbent materials, and provided a surface with more affinity to remove Cu(II).CONACYT-280518 "Fortalecimiento y desarrollo de la infraestructura científica y tecnológica" CONACYT beca escolar No 44972

PRODUCTIVE AND ECONOMIC ANALYSIS OF PRODUCTION UNITS OF BOVINE CATTLE FOR BEEF IN TLATLAYA, ESTADO DE MEXICO

La ganadería doble propósito es una actividad económica importante en zonas rurales por el ingreso que genera de la venta de leche y carne. El objetivo del trabajo fue realizar un análisis socio-económico de unidades de producción (UP) doble propósito (DP), orientadas a la producción de becerros para abasto. La información se obtuvo de 21 UP DP del Municipio de Tlatlaya, Estado de México, seleccionadas mediante muestreo aleatorio, durante 2015. El análisis económico se realizó a través de la metodología de presupuestos por actividad, considerando los ingresos en efectivo por venta de productos agrícolas, ganaderos, y precios y costos de oportunidad. Se observó que son UP con más de 50 años en la actividad, la principal fuente trabajo es la mano de obra familiar y el tamaño de hato es reducido. Más de 70 % de los ingresos provienen de la ganadería, principalmente de la venta de becerros para abasto. El ingreso se completa con la venta de maíz (Zea mays L.). El ingreso total unitario obtenido fue de $1,687.00 MXN por hectárea y$5,104 MXN por vaca. Sin embargo, el margen neto (MN) fue de solo $26,900 MNX. Se concluyó que la ganadería es una actividad económica importante en la zona de estudio. Las UP dedicadas a la producción de becerros para abasto perciben bajos ingresos y presentan un limitado margen de ganancia

Serum mineral profile of lactating Holstein cows in mixed indoor-grazing systems

Introducción. Los minerales juegan un papel muy importante en la nutrición, porque son necesarios para la biosíntesis de nutrientes esenciales. Objetivo. Evaluar el estado mineral en suero sanguíneo, el consumo de minerales y la producción de leche de vacas Holstein en pastoreo suplementadas con distintos niveles de alimento concentrado y tiempo de permanencia en la pradera en el valle de Toluca, México. Materiales y métodos. Se realizaron dos experimentos con un diseño de cuadro Latino 3x3 cada uno en la Universidad Autónoma del Estado de México, realizados en primavera-verano de 2011-2012. En el experimento uno se evaluó el nivel de concentrado en la dieta (3, 5 y 8 kg día-1) en vacas pastoreando; en el experimento dos se evaluaron tres tiempos de permanencia en la pradera (ocho horas continuas; dos tiempos de cuatro horas post-ordeño; y doce horas). En ambos experimentos se ofertó ensilado de maíz a libre consumo en el corral. En suero sanguíneo y alimentos se les midió la concentración de Ca, P, Mg, K, Na, Cu, Fe y Zn. Se realizaron análisis de correlación simple y de regresión múltiple para las variables de estudio. Resultados. El nivel de concentrado y el tiempo de permanencia en la pradera afectaron (p<0,05) el consumo de la mayoría de los minerales; no se cubrieron los requerimientos de Ca, P, Mg, K y Zn, y hubo exceso de Fe. Independientemente de la estrategia de alimentación, el contenido de minerales en suero sanguíneo de los bovinos fue adecuado para P, Na, Cu y Fe; marginal de Ca, deficiente en Mg y Zn; y hubo exceso de K. Conclusiones. El consumo de minerales no fue determinante para predecir la concentración de minerales en suero sanguíneo de vacas lecheras, sin embargo, mostró influencia sobre la producción de leche de vacas bajo dos sistemas de producción mixta pastoreo-estabulación

Forward-central two-particle correlations in p-Pb collisions at root s(NN)=5.02 TeV

Two-particle angular correlations between trigger particles in the forward pseudorapidity range (2.5 2GeV/c. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B. V.Peer reviewe

Event-shape engineering for inclusive spectra and elliptic flow in Pb-Pb collisions at root(NN)-N-S=2.76 TeV

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Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions

We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

Elliptic flow of muons from heavy-flavour hadron decays at forward rapidity in Pb-Pb collisions at root s(NN)=2.76TeV

The elliptic flow, v(2), of muons from heavy-flavour hadron decays at forward rapidity (2.5 <y <4) is measured in Pb-Pb collisions at root s(NN)= 2.76TeVwith the ALICE detector at the LHC. The scalar product, two- and four-particle Q cumulants and Lee-Yang zeros methods are used. The dependence of the v(2) of muons from heavy-flavour hadron decays on the collision centrality, in the range 0-40%, and on transverse momentum, p(T), is studied in the interval 3 <p(T)<10 GeV/c. A positive v(2) is observed with the scalar product and two-particle Q cumulants in semi-central collisions (10-20% and 20-40% centrality classes) for the p(T) interval from 3 to about 5GeV/c with a significance larger than 3 sigma, based on the combination of statistical and systematic uncertainties. The v(2) magnitude tends to decrease towards more central collisions and with increasing pT. It becomes compatible with zero in the interval 6 <p(T)<10 GeV/c. The results are compared to models describing the interaction of heavy quarks and open heavy-flavour hadrons with the high-density medium formed in high-energy heavy-ion collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V.Peer reviewe

Pseudorapidity and transverse-momentum distributions of charged particles in proton-proton collisions at root s=13 TeV

The pseudorapidity (eta) and transverse-momentum (p(T)) distributions of charged particles produced in proton-proton collisions are measured at the centre-of-mass energy root s = 13 TeV. The pseudorapidity distribution in vertical bar eta vertical bar <1.8 is reported for inelastic events and for events with at least one charged particle in vertical bar eta vertical bar <1. The pseudorapidity density of charged particles produced in the pseudorapidity region vertical bar eta vertical bar <0.5 is 5.31 +/- 0.18 and 6.46 +/- 0.19 for the two event classes, respectively. The transverse-momentum distribution of charged particles is measured in the range 0.15 <p(T) <20 GeV/c and vertical bar eta vertical bar <0.8 for events with at least one charged particle in vertical bar eta vertical bar <1. The evolution of the transverse momentum spectra of charged particles is also investigated as a function of event multiplicity. The results are compared with calculations from PYTHIA and EPOS Monte Carlo generators. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe

Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at root s(NN)=2.76TeV

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