48 research outputs found
Reforming of Diesel Fuel for Hydrogen Production over Catalysts Derived from LaCo0.8M0.2O3 (M = Ni, Ru, Fe, Ga)
Seasonal climate predictions in support of water reservoirs management in Spain
Póster presentado en: 1st Climateurope festival celebrado en Valencia, del 5 al 7 de abril de 2017.This work has been partially funded by the FP7 EUPORIAS projec
Very high energy particle acceleration powered by the jets of the microquasar SS 433
SS 433 is a binary system containing a supergiant star that is overflowing
its Roche lobe with matter accreting onto a compact object (either a black hole
or neutron star). Two jets of ionized matter with a bulk velocity of
extend from the binary, perpendicular to the line of sight, and
terminate inside W50, a supernova remnant that is being distorted by the jets.
SS 433 differs from other microquasars in that the accretion is believed to be
super-Eddington, and the luminosity of the system is erg
s. The lobes of W50 in which the jets terminate, about 40 pc from the
central source, are expected to accelerate charged particles, and indeed radio
and X-ray emission consistent with electron synchrotron emission in a magnetic
field have been observed. At higher energies (>100 GeV), the particle fluxes of
rays from X-ray hotspots around SS 433 have been reported as flux
upper limits. In this energy regime, it has been unclear whether the emission
is dominated by electrons that are interacting with photons from the cosmic
microwave background through inverse-Compton scattering or by protons
interacting with the ambient gas. Here we report TeV -ray observations
of the SS 433/W50 system where the lobes are spatially resolved. The TeV
emission is localized to structures in the lobes, far from the center of the
system where the jets are formed. We have measured photon energies of at least
25 TeV, and these are certainly not Doppler boosted, because of the viewing
geometry. We conclude that the emission from radio to TeV energies is
consistent with a single population of electrons with energies extending to at
least hundreds of TeV in a magnetic field of ~micro-Gauss.Comment: Preprint version of Nature paper. Contacts: S. BenZvi, B. Dingus, K.
Fang, C.D. Rho , H. Zhang, H. Zho
Measurement of the Crab Nebula Spectrum Past 100 TeV with HAWC
We present TeV gamma-ray observations of the Crab Nebula, the standard
reference source in ground-based gamma-ray astronomy, using data from the High
Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory. In this analysis we use
two independent energy-estimation methods that utilize extensive air shower
variables such as the core position, shower angle, and shower lateral energy
distribution. In contrast, the previously published HAWC energy spectrum
roughly estimated the shower energy with only the number of photomultipliers
triggered. This new methodology yields a much improved energy resolution over
the previous analysis and extends HAWC's ability to accurately measure
gamma-ray energies well beyond 100 TeV. The energy spectrum of the Crab Nebula
is well fit to a log parabola shape with emission up to at least 100 TeV. For the first
estimator, a ground parameter that utilizes fits to the lateral distribution
function to measure the charge density 40 meters from the shower axis, the
best-fit values are
=(2.350.04)10 (TeV cm
s), =2.790.02, and
=0.100.01. For the second estimator, a neural
network which uses the charge distribution in annuli around the core and other
variables, these values are
=(2.310.02)10 (TeV cm
s), =2.730.02, and
=0.060.010.02. The first set of uncertainties are statistical;
the second set are systematic. Both methods yield compatible results. These
measurements are the highest-energy observation of a gamma-ray source to date.Comment: published in Ap
Effect of remote ischaemic conditioning on clinical outcomes in patients with acute myocardial infarction (CONDI-2/ERIC-PPCI): a single-blind randomised controlled trial.
BACKGROUND: Remote ischaemic conditioning with transient ischaemia and reperfusion applied to the arm has been shown to reduce myocardial infarct size in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). We investigated whether remote ischaemic conditioning could reduce the incidence of cardiac death and hospitalisation for heart failure at 12 months. METHODS: We did an international investigator-initiated, prospective, single-blind, randomised controlled trial (CONDI-2/ERIC-PPCI) at 33 centres across the UK, Denmark, Spain, and Serbia. Patients (age >18 years) with suspected STEMI and who were eligible for PPCI were randomly allocated (1:1, stratified by centre with a permuted block method) to receive standard treatment (including a sham simulated remote ischaemic conditioning intervention at UK sites only) or remote ischaemic conditioning treatment (intermittent ischaemia and reperfusion applied to the arm through four cycles of 5-min inflation and 5-min deflation of an automated cuff device) before PPCI. Investigators responsible for data collection and outcome assessment were masked to treatment allocation. The primary combined endpoint was cardiac death or hospitalisation for heart failure at 12 months in the intention-to-treat population. This trial is registered with ClinicalTrials.gov (NCT02342522) and is completed. FINDINGS: Between Nov 6, 2013, and March 31, 2018, 5401 patients were randomly allocated to either the control group (n=2701) or the remote ischaemic conditioning group (n=2700). After exclusion of patients upon hospital arrival or loss to follow-up, 2569 patients in the control group and 2546 in the intervention group were included in the intention-to-treat analysis. At 12 months post-PPCI, the Kaplan-Meier-estimated frequencies of cardiac death or hospitalisation for heart failure (the primary endpoint) were 220 (8·6%) patients in the control group and 239 (9·4%) in the remote ischaemic conditioning group (hazard ratio 1·10 [95% CI 0·91-1·32], p=0·32 for intervention versus control). No important unexpected adverse events or side effects of remote ischaemic conditioning were observed. INTERPRETATION: Remote ischaemic conditioning does not improve clinical outcomes (cardiac death or hospitalisation for heart failure) at 12 months in patients with STEMI undergoing PPCI. FUNDING: British Heart Foundation, University College London Hospitals/University College London Biomedical Research Centre, Danish Innovation Foundation, Novo Nordisk Foundation, TrygFonden
TiO2 modifications by hydrothermal treatment and doping to improve its photocatalytic behaviour under visible light
Heterogeneous photocatalysis based on TiO2 materials is an interesting method for the treatment of polluted water because it allows degradation of a wide variety of organic contaminant compounds. The performance of TiO2 based photocatalysts was studied by aqueous solutions of methylene blue (MB) as a model contaminant compound by using 50 mg L−1 as initial water contaminant concentration in order to compare the photocatalytic behaviour of TiO2 Degussa P25 and some synthesized photocatalysts by hydrothermal treatment (nanostructured TiO2 and metal-doped nanostructured TiO2 photocatalysts: nanostructured Co–TiO2, nanostructured Fe–TiO2 and nanostructured Mn–TiO2) under UV and visible light irradiation. Photocatalytic materials characterization was carried out by X-ray diffraction (XRD), transmission electron microscopy (TEM), nitrogen adsorption–desorption, mercury porosimetry, XPS and diffuse reflectance UV–vis spectra. An improvement of the photocatalytic activity has been observed when nanostructured and doped photocatalysts were used under visible light irradiation, concluding that the hydrothermal treatment produces a nanostructuration of commercial titania by the formation of nanoparticles, which results in a large decrease of average crystallite size of undoped and doped titania, and in an important increase of BET specific area and total pore area.We would like to thank to Dr Jesús Canales-Vázquez from the Instituto de Energías Renovables (Albacete), for the TEM images. We are also grateful to the Spanish MICECO for funding through the project MAT2010-18743.Peer Reviewe
Anales de Edafología y Agrobiología Tomo 22 Número 11-12
Mikromorphometrische untersuchungeli ·an hohlraumen im boden, van W. Kubiena, W. Beckmann und E. Geyger.-- Adsorción de amoníaco en los geles Si02-Mg0. Calores de adsorción, por Teófilo Fernández Alvarez.-- Los minerales de la arcilla en suelos de la provinc:ia de Salamanca, III, por J. L. Martín Vivaldi, M. Sánchez Camazano y F. Lucena Conde.-- Color en sedimentos, por J. Galván, C. Alvarez, J. Alonso y J. Catalán.-- Disolución parcial de sílice orgánica en suelos, por Josefina Benayas Casares.-- Clases de fósforo inorgánico cambiable isotópicamente en los suelos calizos, por P. de Arambarri.-- Los suelos de la cuenca media del río Tormes, por T. Martín Patiño, J. T. Alonso Pascual y F. Lucena Conde.-- Estudio térmico diferencial y termogravimétrico de sustancias húmicas, por J. A. Acle de Cáceres y M. Sánchez Camazano.-- Composición química de· la flor del limonero Verna. II. Fósforo, por A. Ortuño Martínez, F. Costa Y agüe y S. Llorente Franco.-- Composición química de la flor del limonero Verna. III. Potasio, por A. Ortuño Martínez, F. Costa Yagüe y S. Llorente Franco.-- Notas. Curso Internacional de Edafología y Biología Vegetal.-- Conferencias del Prof. Butenandt·y visitas a Centros del Consejo.-- Decenio Hidrológico Internacional.-- Nombramiento de Director de la Estación Experimental de León.-- Actividad de los Centros.-- Concesión de la Medalla de Oro de la Sociedad Nacional para la Protección de la Naturaleza.-- Curso de Tecnología CerámicaPeer reviewe
Anales de Edafología y Agrobiología Tomo 24 Número 7-8
La morfología de los minerales detríticos en relación con sus propiedades estructurales por J. Pérez Mateos y Galván García.-- Caracterización mineralógica y micromorfológica de algunos suelos calizos del Pirineo, por J. Benayas y A. Higueras.-- Estudio de dos fracciones de ácidos fúlvicos de suelos podsólicos, por Francisco Martín Martínez.-- Aplicación del análisis espectroqulmico a la determinación de fósforo en abonos fosfatados, por Fernando Burriel Martí y Carmen Alvarez Herrero.-- Estudio analítico sobre magnitudes del intercambio catiónico en los suelos por Carlos A. Mazza y Carlos E .. Prelat.-- Efecto de la intensidad de transpiración y del tiempo de cosecha sobre íntercepción radicular,flujo masivo y absorción de. calcio· y magnesio por plantas de soja, por S. Oliver.-- Role of bacteria on the insoluble iron absorption by alfalfa plants;. por María R. Felipe Antón, Karl A. Grossenbacher and H. Fenny.-- Determinaciones del estado energético del agua en los suelos («curvas de pF») por un método biológico, por F. Gonzále, M. A . Ollacarizqueta y C. González.- Ensayo de sorgos forrajeros, por Manuel Capdevila Moret. Notas. Aclaración-- Conferencia sobre Suelos Mediterráneos.-- Premios Francisco Franco» 1964 de Ciencias.—Nombramiento de dos Miembros correspondientes.-- Congresos, Reuniones y Becas.-- Centros.-- lnvitaciones a Profesores extranjeros.-- Primeras Jornadas sobre Fertilizantes .-- Premio Instituto Internacional de la Potasa.-- Asamblea general de la Asociation Internationale des Selectionneurs póur la Protection des Obtentions Végétales.-- Simposium Cuprum Pro Vita.-- Premio agrícola A. E. D. O. S.-- Bibliografía. Análisis mineralógico de arenas (Juan Alotiso)Peer reviewe