Estabilización anaerobia mesofílica y termofílica de lodos activados provenientes de la industria cervecera

In this research was evaluated the degradation of activated sludges from a brewing industry located in Zulia State (Venezuela) under mesophilic condition (MC) to 37º C and termophilic condition (TC) to 55º C throughout the use of an anaerobic digester of suspended growth and complete mixture of 3.5 L, that worked with discontinuous flow. Hydraulic retention times (HRT) of 30, 25 and 15 days were evaluated. The highest removals were obtained by applying the volumetric organic load (VOL) of 1 kg COD m3 /d (30-day HRT), where 32% of the CODtotal were removed, 10% of total solids (TS) and 29% of the volatile solids (VS) for the MC and 59%, 32% and 43% for CODtotal, ST and SV respectively in the TC. The methane concentration in biogas was around 60% for both conditions, and the volatile fatty acid concentration (VFA) stayed always smaller than 35 mg/L indicating that all the acidified COD was transformed to methane.En esta investigación, se evaluó la degradación de lodos activados provenientes de una industria cervecera ubicada en el Estado Zulia (Venezuela) bajo condiciones mesofílicas (CM), a 37º C y condiciones termofílicas (CT), a 55º C mediante el uso de un digestor anaerobio de crecimiento suspendido y mezcla completa de 3,5 L, que trabajó con flujo discontinuo. Se evaluaron tiempos de retención hidráulicos (TRH), de 30, 25 y 15 días. Las mayores remociones se obtuvieron al aplicar la carga orgánica volumétrica (COV), de 1 kg DQO m3 /d (TRH de 30 días), en la cual se removió el 32% de la DQOtotal, 10% de sólidos totales (ST), y 29% de sólidos volátiles (SV), para la CM y 59%, 32% y 43% para DQOtotal, ST y SV respectivamente en la CT. La concentración de metano en el biogás estuvo cerca al 60% para ambas condiciones, y la concentración de ácidos grasos volátiles (AGV) se mantuvo siempre menor a 35 mg/L, indicando que toda la DQO acidificada fue transformada a metano

MODELAGEM HIDROLÓGICA COM O USO DE INFRAESTRUTURAS VERDES: ESTUDO DE CASO PARA A BACIA DO CÓRREGO RESSACA, SITUADA NO MUNICÍPIO DE BELO HORIZONTE

Com o aumento da urbanização nas cidades brasileiras, de maneira desordenada, é mais frequente a ocorrência de inundações, devido ao aumento da taxa de impermeabilização do solo e da vazão de escoamento. Neste sentido, o uso de técnicas compensátorias, também conhecidas como “infraestruturas verdes”, ganhou espaço a partir dos anos 70. Este método de drenagem procura mitigar os problemas de urbanização através da retenção ou infiltração das águas precipitadas. Considerando o exposto, este trabalho propõe a análise do impacto do uso de telhados verdes e pavimentos permeáveis no hidrograma de cheias da Bacia do Córrego do Ressaca, localizada na região da Pampulha em Belo Horizonte-MG, visando tentar mitigar os danos causados pelo processo de drenagem atual. Utilizando o software ABC-6 foram modelados dois cenários distintos para obter a viabilidade da implantação dessas técnicas, sendo modeladas a situação atual da bacia (Cenário 1), sem nenhuma técnica, e um cenário que recebeu a instalação de “infraestruturas verdes” (Cenário 2), para tempos de retorno de 10 e 50 anos. Após a modelagem, observou-se a redução da vazão de pico e do volume escoado para os tempos de retorno (TR) de 10 e 50 anos, porém para o TR de 10 anos o índice de redução é maior. A técnica que mais contribuiu para tais resultados foi o telhado verde, pois a bacia apresentou maior potencial para a instalação desta técnica, se comparado ao potencial para receber pavimentos permeáveis

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

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

Peer reviewe

Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| &lt; 0.03 at 95% confidence level. [Figure not available: see fulltext.

MUSiC : a model-unspecific search for new physics in proton-proton collisions at root s=13TeV

Results of the Model Unspecific Search in CMS (MUSiC), using proton-proton collision data recorded at the LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1), are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.Peer reviewe

Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe

Measurement of prompt open-charm production cross sections in proton-proton collisions at root s=13 TeV

The production cross sections for prompt open-charm mesons in proton-proton collisions at a center-of-mass energy of 13TeV are reported. The measurement is performed using a data sample collected by the CMS experiment corresponding to an integrated luminosity of 29 nb(-1). The differential production cross sections of the D*(+/-), D-+/-, and D-0 ((D) over bar (0)) mesons are presented in ranges of transverse momentum and pseudorapidity 4 < p(T) < 100 GeV and vertical bar eta vertical bar < 2.1, respectively. The results are compared to several theoretical calculations and to previous measurements.Peer reviewe

Combined searches for the production of supersymmetric top quark partners in proton-proton collisions at root s=13 TeV

A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 137 fb(-1) collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on themodel, the combined result excludes a top squarkmass up to 1325 GeV for amassless neutralino, and a neutralinomass up to 700 GeV for a top squarkmass of 1150 GeV. Top squarks with masses from 145 to 295 GeV, for neutralino masses from 0 to 100 GeV, with a mass difference between the top squark and the neutralino in a window of 30 GeV around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420 GeV