Predicted rates of merging neutron stars in galaxies

In this work, we compute rates of merging neutron stars (MNS) in galaxies of different morphological type, as well as the cosmic MNS rate in a unitary volume of the Universe adopting different cosmological scenarios. Our aim is to provide predictions of kilonova rates for future observations both at low and high redshift. In the adopted galaxy models, we take into account the production of r-process elements either by MNS or core-collapse supernovae. In computing the MNS rates we adopt either a constant total time delay for merging (10 Myr) or a distribution function of such delays. Our main conclusions are: i) the observed present time MNS rate in our Galaxy is well reproduced either with a constant time delay or a distribution function $\propto t^{-1}$. The [Eu/Fe] vs. [Fe/H] relation in the Milky Way can be well reproduced with only MNS, if the time delay is short and constant. If the distribution function of delays is adopted, core-collapse supernovae as are also required. ii) The present time cosmic MNS rate can be well reproduced in any cosmological scenario, either pure luminosity evolution or a typical hierarchical one, and spirals are the main contributors to it. iii) The spirals are the major contributors to the cosmic MNS at all redshifts in hierarchical scenarios. In the pure luminosity evolution scenario, the spirals are the major contributors locally, whereas at high redshift ellipticals dominate. iv) The predicted cosmic MNS rate well agrees with the cosmic rate of short Gamma Ray Bursts if the distribution function of delays is adopted, in a cosmological hierarchical scenario observationally derived. v) Future observations of Kilonovae in ellipticals will allow to disentangle among constant or a distribution of time delays as well as among different cosmological scenarios

Iongel Soft Solid Electrolytes Based on [DEME][TFSI] Ionic Liquid for Low Polarization Lithium-O-2 Batteries

Lithium-air/O-2 batteries are a promising battery technology for automotive applications due to their high energy density. However, many challenges need to be solved, particularly the high reactivity of the electrolyte with oxygen superoxide radicals and its low cyclability. In this work, we present a simple and fast way to prepare polymer-based iongel soft solid electrolytes. Thermally and mechanically stable iongels are prepared by fast UV-photopolymerisation exhibiting a high ionic conductivity (similar to 1.2 x 10(-3) S cm(-1) at 25 degrees C). When used as solid electrolytes in lithium symmetrical cells, they can withstand a critical current density of 0.5 mA cm(-2). Performance in Li-O-2 cells showed capacities as large as 3.3 mAh cm(-2), and cycling capability of 25 cycles, exceeding results on liquid-counterpart cells.European Commission's funded Marie Skłodowska-Curie. Grant Number: 76582

New poly(ionic liquid)s based on poly(azomethine-pyridinium) salts and its use as heterogeneous catalysts for CO2 conversion

A fast and simple synthetic route towards a new family of poly(ionic liquids) based on aromatic crosslinked poly(azomethine-pyridinium) salts is described. These new polymers were prepared in one step from new diamine methyl pyridinium salts and isopthaldehyde, in 30 min under microwave irradiation. By this method, poly(azomethine-pyridinium) containing chloride (Cl), bis(trifluoromethylsulfonyl)imide (TFSI) and hexaflorophosphate (PF6) as counter-anions were synthetized. This new pyridinium poly(ionic liquid)s were obtained as insoluble powders showing high thermal stability. The poly(azomethine-pyridinium)s were tested as heterogeneous catalysts in the cycloaddition of CO2 to epichlorohydrin to obtain chloropropylene carbonate. The polymers containing chloride anion shows high content of catalytically active sites and the best performance of the series, with 100% selectivity towards the chloropropylene carbonate in a reaction without solvent at 3 bar of CO2, 100 °C and low catalyst loading (0.5 mol%).Spanish Government, MINECO (Projects MAT2014-52085-C2-2-P and MAT2017-82288-C2-2-P, MAT2017-83373-R

La Universidad del Renacimiento, el renacimiento de la Universidad

Con esta nueva exposición la Universidad Complutense de Madrid conmemora el 500 Aniversario de la primera impresión de El Nuevo  Testamento, llevada a cabo en 1514 como parte de los finalmente seis volúmenes de la obra, cuya publicación total culminó ocho años después. Probablemente la elaboración de la Biblia Políglota fue el empeño académico más ambicioso e innovador del momento en el ámbito de las Humanidades; pero además marcó con su rigor el paradigma de excelencia que, desde entonces, cualquier ámbito científico busca alcanzar en su función

El Boletín del Documentalista, nº 19

Depto. de Biblioteconomía y DocumentaciónFac. de Ciencias de la Documentaciónpu

Origin of neutron capture elements with the Gaia-ESO survey: the evolution of s- and r-process elements across the Milky Way

We study the abundance patterns and the radial gradients of s-process elements (Y, Zr, Ba, La and Ce), r-process elements (Eu) and mixed-process elements (Mo, Nd and Pr) in the Galactic thin disc by means of a detailed two-infall chemical evolution model for the Milky Way with state-of-the-art nucleosynthesis prescriptions. We consider r-process nucleosynthesis from merging neutron stars (MNS), magneto-rotational supernovae (MR-SNe) and s-process synthesis from low- and intermediate- mass stars (LIMS) and rotating massive stars. The predictions of our model are compared with data from the sixth data release of the Gaia-ESO survey, from which we consider 62 open clusters with age > 0.1 Gyr and 1300 Milky Way disc field stars. We conclude that: i) the [Eu/Fe] vs. [Fe/H] is reproduced by both a prompt and a delayed source, but the quick source completely dominates the Eu production; ii) rotation in massive stars contribute substantially to the s-process elements of the first peak, but MNS and MR-SNe are necessary in order to reproduce the observations; iii) due to the adopted yields, our model overpredicts Pr and underpredicts Nd, while the [Mo/Fe] vs. [Fe/H] is nicely reproduced. For the radial gradients, we conclude that: i) our predicted slope of the [Fe/H] gradient is in agreement with the one observed in open clusters by Gaia-ESO and other high-resolution spectroscopic surveys. ii) The predicted slope of the [Eu/H] radial gradient is steeper than the observed one, independently on how quick the production of Eu is. We discuss the possible causes of this discrepancy in terms of both different Galaxy formation scenarios and stellar radial migration effects. iii) For all the elements belonging to the second s-process peak (Ba, La, Ce) as well as for Pr, we predict a plateau at low Galactocentric distances, which is probably due to the enhanced enrichment from LIMS in the inner regions.Comment: 17 pages, 11 figures. Submitted to MNRA

From Plastic Waste to New Materials for Energy Storage

The use of plastic waste to develop high added value materials, also known as upcycling, is a useful strategy towards the development of more sustainable materials. More specifically, the use of plastic waste as a feedstock for synthesising new materials for energy storage devices can not only provide a route to upgrading plastic waste but can also help in the search for sustainable materials. This perspective describes recent strategies for the use of plastic waste as a sustainable, cheap and abundant feedstock in the production of new materials for electrochemical energy storage devices such as lithium batteries, sodium batteries and supercapacitors. Two main strategies are described, the development of conducting carbons by combustion of plastic waste and the depolymerization of plastics into new chemicals and materials. In both cases, catalysis has been key to ensuring high efficiency and performance. Future opportunities and challenges are highlighted and hypotheses are made on how the use of plastic waste could enhance the circularity of current energy storage devices.NG acknowledges the funding from the European Union’s Horizon 2020 framework programme under the Marie Skłodowska-Curie agreement No. 101028682. CJ acknowledges the financial support from el Ministerio de ciencia e innovación from the Juan de la Cierva Program (FJC2020-045872-I). The funding from the European Union’s Horizon 2020 framework programme under the Marie Skłodowska-Curie agreement No. 101028975 and Ministerio de ciencia e innovación under PDC2021-121461-I00 project is acknowledged

Single-ion lithium conducting polymers with high ionic conductivity based on borate pendant groups

This communication reports a family of single-ion lithium conducting polymer electrolytes based on highly delocalized borate groups is reported. The effect of the nature of the substituents on the boron atom on the ionic conductivity of the resultant methacrylic polymers was analyzed. To the best of our knowledge the lithium borate polymers endowed with flexible and electron-withdrawing substituents presents the highest ionic conductivity reported for a lithium single-ion conducting homopolymer (1.65×10−4 S cm−1 at 60 °C). This together with its high lithium transference number tLi+= =0.93 and electrochemical stability window of 4.2 V vs Li0/Li+ show promise for application in lithium batteries. To illustrate this, a lithium borate monomer was integrated into a single-ion gel polymer electrolyte which showed good performance on lithium symmetrical cells (<0.85 V at ±0.2 mA cm−2 for 175 h).This work was supported by a Grant for Basque Government through grant IT1309-19, and European Commission’s funded Marie Skłodowska-Curie project POLYTE-EID (project no. 765828) and Spanish MCIN/ AEI/ PID2020-119026GB-I00. G.G-G. is grateful to "Secretaría de Educación, Ciencia, Tecnología e Innovación" from Ciudad de México for the postdoctoral fellowship through grant (SECTEI/133/2019)

Influence of synoptic meteorology on airborne allergenic pollen and spores in an urban environment in Northeastern Iberian Peninsula

The influence of the most frequent patterns of synoptic circulation on the dynamics of airborne pollen/spores recorded at the Barcelona Aerobiological Station (BCN) was analysed. Six pollen types (Platanus, Cupressaceae, Olea, Poaceae, Urticaceae and Amaranthaceae), and one fungal spore (Alternaria) were selected for their high allergenic effect in sensitive people. Six synoptic meteorological patterns were identified through cluster analysis of sea level pressure fields as the main responsible of the weather conditions in the Iberian Peninsula. The local meteorological conditions in Barcelona associated with each one of the synoptic types were also stablished. Different statistical methods were applied to analyse possible relationships between concentrations and timing of the recorded aerobiological particles and specific synoptic types. The study, focused in the 19-year period 2001–2019, shows that one of the scenarios, frequent in winter and linked to high stability and air-mass blockage, registered the highest mean and median values for Platanus and Cupressaceae, but it was not very relevant for the other taxa. It was also this scenario that turned out to be the most influent on the pollination timing showing a significant influence on the start occurrence of Urticaceae flowering and on the peak date of Platanus. On the other hand, the most frequent synoptic type in the period, relevant in spring and summer, was linked to sporadic episodes of levels considered to be of high risk of allergy to Platanus, Poaceae, and Urticaceae pollen, and Alternaria fungal spore. This synoptic pattern, characterized by the presence of the Azores anticyclone and the Atlantic low located in the north of the United Kingdom, was associated with high temperatures, low relative humidity and moderate winds from the NW in Barcelona. The identification of an interaction between synoptic meteorology and pollen/spore dynamics will allow better abatement measures, reducing adverse health effects on sensitive population.Peer ReviewedPostprint (published version