Moisture damage resistance of bituminous mixtures manufactured with waste biomass fly ashes form the paper industry as filler

Este póster foi presentado no congreso "8th EATA Asphalt Conference 2019", que foi organizado pola European Asphalt Technology Association e a Universidad de Granada, e que tivo lugar en Granada, entre o 3 e o 5 de xuño de 2019.[Abstract:] Biomass fly ashes (bioashes) are solid byproducts generated during the combustion of biomass. One of the main drawbacks of using biomass combustion as an energy source is the environmental management of the resulting bioashes. In this regard, some researchers have analysed the feasibility of using bioashes as filler for bituminous mixtures with encouraging results. Nevertheless, previous investigations concluded that the use of biomass waste fly ashes from the paper industry (BioFAPI) lead to bituminous mixtures with inadequate water resistance.Ministerio de Economía y Competitividad; ITC‐20133075Ministerio de Economía y Competitividad; BIA2010‐17751Ministerio de Economía y Competitividad; BES‐2011‐04437

Mechanochemically Synthetized PAN-Based Co-N-Doped Carbon Materials as Electrocatalyst for Oxygen Evolution Reaction

We report a new class of polyacrylonitrile (PAN)-based Co-N-doped carbon materials that can act as suitable catalyst for oxygen evolution reactions (OER). Different Co loadings were mechanochemically added into post-consumed PAN fibers. Subsequently, the samples were treated at 300 °C under air (PAN-A) or nitrogen (PAN-N) atmosphere to promote simultaneously the Co3O4 species and PAN cyclization. The resulting electrocatalysts were fully characterized and analyzed by X-ray diffraction (XRD) and photoelectron spectroscopy (XPS), transmission (TEM) and scanning electron (SEM) microscopies, as well as nitrogen porosimetry. The catalytic performance of the Co-N-doped carbon nanomaterials were tested for OER in alkaline environments. Cobalt-doped PAN-A samples showed worse OER electrocatalytic performance than their homologous PAN-N ones. The PAN-N/3% Co catalyst exhibited the lowest OER overpotential (460 mV) among all the Co-N-doped carbon nanocomposites, reaching 10 mA/cm2. This work provides in-depth insights on the electrocatalytic performance of metal-doped carbon nanomaterials for OER

Palaeoenvironmental analysis of the Aragonian (middle Miocene) mammalian faunas from the Madrid Basin based on body-size structure

As a consequence of the growth of the Antarctic ice-sheet during the middle Miocene, a global decrease of temperatures and an associated increase in aridity provoked several environmental changes all around the world. Such environmental variations can be detected in the continental record of the mammalian prey community structure using a synecological approach. Because of the good quality of its faunas, the rich Aragonian vertebrate fossil record from the Madrid Basin (Spain) appears as a good candidate to explore these environmental changes. In order to analyse the climatic evolution of the Iberian Peninsula associated to the Global Cooling Event, two classic palaeosynecological methodologies (cenograms and body size diversity), based on body-size community structure, were applied to 6 fossil sites from the Madrid Basin, ranging over 2 million years (15.5 – 13.5 Ma). To establish a comparative framework, we used the ecological faunal data from 100 modern localities uniformly distributed all around the world. Our palaeoenvironmental inference is based on multivariate discriminant analysis of the dataset containing both modern and fossil mammals. Finally, we can conclude that the Aragonian mammalian assemblage from the Madrid Basin showed a predominance of semiarid environments with pulses of higher aridity in biozones Dc, E and F associated with the Global Cooling Event of the middle Miocene.Como consecuencia del crecimiento del casquete polar Antártico, durante el Mioceno medio, se produjo un descenso global de la tem­peratura asociado a un aumento de la aridez. Este tipo de cambios ambientales pueden ser detectados en el registro continental, siguiendo un modelo sinecológico para analizar la estructura de las comunidades de las faunas de mamíferos herbívoros. Debido a la calidad de sus faunas, el registro fósil de las faunas de vertebrados del Aragoniense de la Cuenca de Madrid se antoja como un buen candidato para explorar estos patrones de cambio ambiental. Con el objetivo de analizar la evolución climática de la Península Ibérica asociada al evento de enfriamiento global durante este lapso temporal, dos metodologías paleosinecológicas clásicas (cenogramas y espectros de diversidad de tamaño corporal), basadas en la estructura de tamaños corporales de las comunidades de mamíferos, han sido aplicadas a la fauna de herbívoros fósiles presente en seis yacimientos de la Cuenca de Madrid, abarcando aproximadamente 2 millones de años (15.5 – 13.5 Ma). Se ha establecido un marco comparativo usando los datos ecológicos de la fauna de mamíferos presente en 100 localidades uniformemente distribuidas por todo el planeta. Esta inferencia paleoambiental está basada en la aplicación de análisis discriminante multivariante sobre el conjunto de datos de las faunas actuales y fósiles. Finalmente, las faunas de mamíferos del Aragoniense de la Comunidad de Madrid mostraron una predominancia de ambientes semiáridos con varios pulsos de mayor aridez en las biozonas Dc, E y F asociados al evento de enfriamiento global del Mioceno medio

High accuracy 234U(n,f) cross section in the resonance energy region

New results are presented of the 234U neutron-induced fission cross section, obtained with high accuracy in the resonance region by means of two methods using the 235U(n,f) as reference. The recent evaluation of the 235U(n,f) obtained with SAMMY by L. C. Leal et al. (these Proceedings), based on previous n-TOF data [1], has been used to calculate the 234U(n,f) cross section through the 234U/235U ratio, being here compared with the results obtained by using the n-TOF neutron flux

Characterization of the n-TOF EAR-2 neutron beam

The experimental area 2 (EAR-2) at CERNs neutron time-of-flight facility (n-TOF), which is operational since 2014, is designed and built as a short-distance complement to the experimental area 1 (EAR-1). The Parallel Plate Avalanche Counter (PPAC) monitor experiment was performed to characterize the beam prole and the shape of the neutron 'ux at EAR-2. The prompt γ-flash which is used for calibrating the time-of-flight at EAR-1 is not seen by PPAC at EAR-2, shedding light on the physical origin of this γ-flash

Measurement of the 240Pu(n,f) cross-section at the CERN n-TOF facility : First results from experimental area II (EAR-2)

The accurate knowledge of the neutron-induced fission cross-sections of actinides and other isotopes involved in the nuclear fuel cycle is essential for the design of advanced nuclear systems, such as Generation-IV nuclear reactors. Such experimental data can also provide the necessary feedback for the adjustment of nuclear model parameters used in the evaluation process, resulting in the further development of nuclear fission models. In the present work, the 240Pu(n,f) cross-section was measured at CERN's n-TOF facility relative to the well-known 235U(n,f) cross section, over a wide range of neutron energies, from meV to almost MeV, using the time-of-flight technique and a set-up based on Micromegas detectors. This measurement was the first experiment to be performed at n-TOF's new experimental area (EAR-2), which offers a significantly higher neutron flux compared to the already existing experimental area (EAR-1). Preliminary results as well as the experimental procedure, including a description of the facility and the data handling and analysis, are presented

New measurement of the 242Pu(n,γ) cross section at n-TOF-EAR1 for MOX fuels : Preliminary results in the RRR

The spent fuel of current nuclear reactors contains fissile plutonium isotopes that can be combined with 238U to make mixed oxide (MOX) fuel. In this way the Pu from spent fuel is used in a new reactor cycle, contributing to the long-term sustainability of nuclear energy. The use of MOX fuels in thermal and fast reactors requires accurate capture and fission cross sections. For the particular case of 242Pu, the previous neutron capture cross section measurements were made in the 70's, providing an uncertainty of about 35% in the keV region. In this context, the Nuclear Energy Agency recommends in its "High Priority Request List" and its report WPEC-26 that the capture cross section of 242Pu should be measured with an accuracy of at least 7-12% in the neutron energy range between 500 eV and 500 keV. This work presents a brief description of the measurement performed at n-TOF-EAR1, the data reduction process and the first ToF capture measurement on this isotope in the last 40 years, providing preliminary individual resonance parameters beyond the current energy limits in the evaluations, as well as a preliminary set of average resonance parameters

GEANT4 simulation of the neutron background of the C6D6 set-up for capture studies at n_TOF

The neutron sensitivity of the C6D6 detector setup used at n_TOF facility for capture measurements has been studied by means of detailed GEANT4 simulations. A realistic software replica of the entire n_TOF experimental hall, including the neutron beam line, sample, detector supports and the walls of the experimental area has been implemented in the simulations. The simulations have been analyzed in the same manner as experimental data, in particular by applying the Pulse Height Weighting Technique. The simulations have been validated against a measurement of the neutron background performed with a natC sample, showing an excellent agreement above 1 keV. At lower energies, an additional component in the measured natC yield has been discovered, which prevents the use of natC data for neutron background estimates at neutron energies below a few hundred eV. The origin and time structure of the neutron background have been derived from the simulations. Examples of the neutron background for two different samples are demonstrating the important role of accurate simulations of the neutron background in capture cross-section measurements

Experimental neutron capture data of 58Ni from the CERN n_TOF facility

The neutron capture cross section of 58 Ni was measured at the neutron time of flight facility n-TOF at CERN, from 27 meV to 400 keV neutron energy. Special care has been taken to identify all the possible sources of background, with the so-called neutron background obtained for the first time using high-precision GEANT4 simulations. The energy range up to 122 keV was treated as the resolved resonance region, where 51 resonances were identified and analyzed by a multilevel R-matrix code SAMMY. Above 122 keV the code SESH was used in analyzing the unresolved resonance region of the capture yield. Maxwellian averaged cross sections were calculated in the temperature range of κT = 5 - 100 keV, and their astrophysical implications were investigated

Fission Fragment Angular Distribution measurements of 235U and 238U at CERN n_TOF facility

Neutron-induced fission cross sections of $^{238}$U and $^{235}$U are used as standards in the fast neutron region up to 200 MeV. A high accuracy of the standards is relevant to experimentally determine other neutron reaction cross sections. Therefore, the detection efficiency should be corrected by using the angular distribution of the fission fragments (FFAD), which are barely known above 20 MeV. In addition, the angular distribution of the fragments produced in the fission of highly excited and deformed nuclei is an important observable to investigate the nuclear fission process. In order to measure the FFAD of neutron-induced reactions, a fission detection setup based on parallel-plate avalanche counters (PPACs) has been developed and successfully used at the CERN-n_TOF facility. In this work, we present the preliminary results on the analysis of new $^{235}$U(n,f) and $^{238}$U(n,f) data in the extended energy range up to 200 MeV compared to the existing experimental data