Degradación fotocatalítica de los contaminantes 2-clorofenol y 4-clorofenol presentes en agua residuales empleando SBA-15 modificado con galio como fotocatalizador

En el presente proyecto de investigación a nivel maestría se estudia el efecto de la incorporación de galio en diferentes proporciones en peso (1, 3, 5 y 10%) a la estructura mesoporosa SBA-15 caracterizando sus propiedades químicas, físicas, texturales y ópticas, y su actividad catalítica en la degradación fotocatalítica de los contaminantes presentes en aguas residuales. La síntesis de los distintos materiales se llevó a cabo utilizando el método de coprecipitación a temperatura constante en un baño térmico con el propósito de una adecuada incorporación de galio a la estructura mesoporosa. Se realizó la síntesis de materiales SBA-15 modificados con galio, manteniendo un pH y temperatura constante durante la síntesis, lo anterior con el propósito de controlar el tamaño de poro y área superficial para obtener una mayor eficiencia en la actividad catalítica. La evaluación catalítica se realizó utilizando una fuente de irradiación de luz (UV) para la degradación fotocatalítica de los contaminantes presentes en aguas residuales como 2- Clorofenol y 4-Clorofenol utilizando los fotocatalizadores SBA-15 modificados con galio, las reacciones de degradación fueron seguidas utilizando un espectrofotómetro de Uv-Vis, los resultados experimentales indicaron que el mayor porcentaje de degradación de estos contaminantes se obtienen con SBA-15 modificada con galio a un 3% en peso. Este resultado se puede explicar por un intercambio interatómico de heteroátomos de silicio y galio dentro de la estructura de SBA-15, es importante mencionar que se obtiene casi el mismo porcentaje de degradación de este material y el óxido de galio, la importancia de esta comparación es que se requiere una menor cantidad de óxido de galio para que se lleve a cabo este proceso de degradación, que la estructura de SBA-15 mantuvo sus características de estabilidad estructural, aun cuando sus propiedades físicas se vieron un poco modificadas, por lo que se puede decir que es un buen soporte

Evaluación de la actividad catalítica de MCM-41-Zn en la reacción de oxidación de benzaldehído utilizando O₂ como agente oxidante

En el presente trabajo se describe el diseño y la síntesis del material mesoporoso MCM-41 dopado con Zn, obtenido mediante la técnica de co¬precipitación, así como su aplicación como modulador de la reactividad en la reacción de oxidación de benzaldehído a ácido benzoico, empleando oxígeno molecular como agente oxidante. El catalizador mesoporoso MCM-41-Zn promueve la formación del producto de oxidación con una conversión del 90% y rendimientos del 100% en condiciones de reacción moderadas y tiempos de reacción cortos. Se presenta la comparación y optimización de las condiciones de reacción empleando diversas metodologías: síntesis con calentamiento convencional, síntesis asistida por microondas, así como mecanosíntesis.The present work describes the design and synthesis of a Zn doped MCM-41 mesoporous material, obtained by co-precipitation technique, and its application as a reactivity modulator in the oxidation reaction of benzaldehyde to benzoic acid, by using molecular oxygen as oxidant reagent. Mesoporous catalyst MCM-41-Zn promotes the formation of the oxidation product with conversions of 90% and yields of 100% in moderated reaction conditions and short reaction times. A comparison and optimization of the reaction conditions of diverse synthetic methodologies is presented: Conventional heating, Microwave assisted and mechanosynthesis

Vocabulario de la sociedad civil, la ruralidad y los movimientos sociales en América Latina

El Vocabulario de la Sociedad Civil, la Ruralidad y los Movimientos Sociales en América Latina tiene como objetivo desarrollar vocablos relacionados con temas de gran trascendencia para la vida colectiva de la población Latinoamericana; pretende introducir a estudiantes, personas del ámbito académico y activistas en la comprensión de estas categorías de análisis. A través de la mirada de 70 especialistas que participaron en este vocabulario, es posible comprender muchos de los términos que se utilizan dentro de la investigación social y áreas relacionadas con las ciencias políticas, ambientales y rurales, a partir de una mayor explicación y detalle. Es por ello que se inserta este trabajo desde una mirada colectiva y amplia de los conceptos que se exponen. En este libro podrá encontrar las ideas de varios autores y autoras de distintas universidades, con una visión multi, inter y transdisciplinaria. El esfuerzo que se realizó para conjuntar varios términos y analizar su compleja red de interpretaciones, permitirá que este manuscrito pueda ser consultado por estudiantes, personas del ámbito científico-académico, y ciudadanía; porque contiene el estado del arte, la historia del paulatino avance de múltiples conceptos y su vigencia en el contexto actual

The Helicobacter pylori Genome Project : insights into H. pylori population structure from analysis of a worldwide collection of complete genomes

Helicobacter pylori, a dominant member of the gastric microbiota, shares co-evolutionary history with humans. This has led to the development of genetically distinct H. pylori subpopulations associated with the geographic origin of the host and with differential gastric disease risk. Here, we provide insights into H. pylori population structure as a part of the Helicobacter pylori Genome Project (HpGP), a multi-disciplinary initiative aimed at elucidating H. pylori pathogenesis and identifying new therapeutic targets. We collected 1011 well-characterized clinical strains from 50 countries and generated high-quality genome sequences. We analysed core genome diversity and population structure of the HpGP dataset and 255 worldwide reference genomes to outline the ancestral contribution to Eurasian, African, and American populations. We found evidence of substantial contribution of population hpNorthAsia and subpopulation hspUral in Northern European H. pylori. The genomes of H. pylori isolated from northern and southern Indigenous Americans differed in that bacteria isolated in northern Indigenous communities were more similar to North Asian H. pylori while the southern had higher relatedness to hpEastAsia. Notably, we also found a highly clonal yet geographically dispersed North American subpopulation, which is negative for the cag pathogenicity island, and present in 7% of sequenced US genomes. We expect the HpGP dataset and the corresponding strains to become a major asset for H. pylori genomics

Challenge 9: Towards an Ocean-Engaged Society

Challenge 9.-- Coordinators: José Pintado Valverde (IIM, CSIC), Ana Crespo Solana (IH-CCHS, CSIC).-- 20 pages, 4 figures.The Ocean has shaped human societies, providing resources and ways of communication, trade, exploration and expansion. Understanding the interactions with Society in the past and the present, is essential to tackle the challenges that face the future of the Ocean. With that aim, this chapter develops the consilience between Ocean Science, Social Sciences and Humanities, leading to the integration of diverse methodologies in an interdisciplinary framework. This holistic approach will be used to increase the knowledge and understanding of the interactions of the Oceans with Society by integrating digital and historical data, and natural and cultural heritage management and protection; connecting Ocean and Cultural Heritage Literacy to promote social change and citizen participation in research; developing interdisciplinary knowledge to base Governance and Management and to foster Sustainable Blue Economy, bridging Local and Indigenous Knowledge with Science-based knowledgePeer reviewe

Measurement of electrons from beauty-hadron decays in p–Pb collisions at √sNN = 5.02 TeV and Pb–Pb collisions at √sNN = 2.76 TeV

The production of beauty hadrons was measured via semi-leptonic decays at mid-rapidity with the ALICE detector at the LHC in the transverse momentum interval 1<pT<8 GeV/c in minimum-bias p-Pb collisions at sNN−−−√=5.02 TeV and in 1.3<pT<8 GeV/c in the 20% most central Pb-Pb collisions at sNN−−−√=2.76 TeV. The pp reference spectra at s√=5.02 TeV and s√=2.76 TeV, needed for the calculation of the nuclear modification factors RpPb and RPbPb, were obtained by a pQCD-driven scaling of the cross section of electrons from beauty-hadron decays measured at s√=7 TeV. In the pT interval 3<pT<8 GeV/c a suppression of the yield of electrons from beauty-hadron decays is observed in Pb-Pb compared to pp collisions. Towards lower pT, the RPbPb values increase with large systematic uncertainties. The RpPb is consistent with unity within systematic uncertainties and is well described by theoretical calculations that include cold nuclear matter effects in p-Pb collisions. The measured RpPb and these calculations indicate that cold nuclear matter effects are small at high transverse momentum also in Pb-Pb collisions. Therefore, the observed reduction of RPbPb below unity at high pT may be ascribed to an effect of the hot and dense medium formed in Pb-Pb collisions

Elliptic flow of electrons from heavy-flavour hadron decays at mid-rapidity in Pb–Pb collisions at √sNN = 2.76 TeV

The elliptic flow of electrons from heavy-flavour hadron decays at mid-rapidity (|y| < 0.7) is measured in Pb-Pb collisions at sNN−−−√=2.76 TeV with ALICE at the LHC. The particle azimuthal distribution with respect to the reaction plane can be parametrized with a Fourier expansion, where the second coefficient (v2) represents the elliptic flow. The v2 coefficient of inclusive electrons is measured in three centrality classes (0-10%, 10-20% and 20-40%) with the event plane and the scalar product methods in the transverse momentum (pT) intervals 0.5-13 GeV/c and 0.5-8 GeV/c, respectively. After subtracting the background, mainly from photon conversions and Dalitz decays of neutral mesons, a positive v2 of electrons from heavy-flavour hadron decays is observed in all centrality classes, with a maximum significance of 5.9σ in the interval 2< pT < 2.5 GeV/c in semi-central collisions (20-40%). The value of v2 decreases towards more central collisions at low and intermediate pT (0.5 < pT < 3 GeV/c). The v2 of electrons from heavy-flavour hadron decays at mid-rapidity is found to be similar to the one of muons from heavy-flavour hadron decays at forward rapidity (2.5 < y < 4). The results are described within uncertainties by model calculations including substantial elastic interactions of heavy quarks with an expanding strongly-interacting medium

Centrality dependence of charged jet production in p–Pb collisions at √sNN = 5.02 TeV

Measurements of charged jet production as a function of centrality are presented for p-Pb collisions recorded at sNN−−−√=5.02 TeV with the ALICE detector. Centrality classes are determined via the energy deposit in neutron calorimeters at zero degree, close to the beam direction, to minimise dynamical biases of the selection. The corresponding number of participants or binary nucleon-nucleon collisions is determined based on the particle production in the Pb-going rapidity region. Jets have been reconstructed in the central rapidity region from charged particles with the anti-kT algorithm for resolution parameters R=0.2 and R=0.4 in the transverse momentum range 20 to 120 GeV/c. The reconstructed jet momentum and yields have been corrected for detector effects and underlying-event background. In the five centrality bins considered, the charged jet production in p-Pb collisions is consistent with the production expected from binary scaling from pp collisions. The ratio of jet yields reconstructed with the two different resolution parameters is also independent of the centrality selection, demonstrating the absence of major modifications of the radial jet structure in the reported centrality classes

Pseudorapidity dependence of the anisotropic flow of charged particles in Pb–Pb collisions at √sNN = 2.76 TeV

We present measurements of the elliptic (v2), triangular (v3) and quadrangular (v4) anisotropic azimuthal flow over a wide range of pseudorapidities (−3.5<η<5). The measurements are performed with Pb-Pb collisions at sNN−−−√=2.76 TeV using the ALICE detector at the Large Hadron Collider (LHC). The flow harmonics are obtained using two- and four-particle correlations from nine different centrality intervals covering central to peripheral collisions. We find that the shape of vn(η) is largely independent of centrality for the flow harmonics n=2−4, however the higher harmonics fall off more steeply with increasing |η|. We assess the validity of extended longitudinal scaling of v2 by comparing to lower energy measurements, and find that the higher harmonic flow coefficients are proportional to the charged particle densities at larger pseudorapidities. Finally, we compare our measurements to both hydrodynamical and transport models, and find they both have challenges when it comes to describing our data