Fast microwave-assisted synthesis of Li-stuffed garnets and insights into Li diffusion from muon spin spectroscopy

Lithium-stuffed garnets attract huge attention due to their outstanding potential as solid-state electrolytes for lithium batteries. However, there exists a persistent challenge in the reliable synthesis of these complex functional oxides together with a lack of complete understanding of the lithium-ion diffusion mechanisms in these important materials. Addressing these issues is critical to realizing the application of garnet materials as electrolytes in all solid-state lithium-ion batteries. In this work, a cubic phase garnet of nominal composition Li6.5Al0.25La2.92Zr2O12 is synthesized through a microwave-assisted solid-state route for the first time, reducing considerably the reaction times and heating temperatures. Lithium-ion diffusion behavior is investigated by electrochemical impedance spectroscopy (EIS) and state-of-art muon spin relaxation (μSR) spectroscopy, displaying activation energies of 0.55 ± 0.03 eV and 0.19 ± 0.01 eV respectively. This difference arises from the high inter-grain resistance, which contributes to the total resistance in EIS measurements. In contrast, μSR acts as a local probe providing insights on the order of the lattice, giving an estimated value of 4.62 × 10−11 cm2 s−1 for the lithium diffusion coefficient. These results demonstrate the potential of this lithium-stuffed garnet as a solid-state electrolyte for all-solid state lithium-ion batteries, an area of growing interest in the energy storage community

Nano-alambres de dioxido de manganeso como material electroactivo en supercondensadores

III Encuentro sobre Nanociencia y Nanotecnología de Investigadores y Tecnólogos Andaluce

Enantioselective organocatalyzed aza-Michael addition reaction of 2-hydroxybenzophenone imines to nitroolefins under batch and flow conditions

Herein, an asymmetric organocatalytic aza-Michael addition reaction of ketimines to nitroolefins is presented. The use of 2-hydroxybenzophenone imine improves the enantioselective addition of N-centered nucleophiles to nitroalkenes by means of intramolecular hydrogen bond formation at the imine moiety. Moreover, the versatility of the process is demonstrated under both batch and flow conditions, showing the synthesis of a large variety of nitroamine derivatives with excellent yields and enantioselectivities. In addition, we applied this methodology to the formal synthesis of VNI, a drug-like scaffold for the treatment of Chagas diseaseWe acknowledge the financial support by the Spanish Govern ment (RTI2018-095038-B-I00) and ERC (ERC-CG, 647550, ERC-PoC, Contract No. 861930

Nanomateriales cristalinos como electrodos en bacterías acuosas Li-ión

II Encuentro sobre nanociencia y nanotecnología de investigadores y tecnólogos de la Universidad de Córdoba. NANOUC

A Bound on the Existence of the Maximum Jointly Invariant Set of Input-Coupled Systems

We present a set-theoretical characterization of a bound on the maximal portion that an agent can cede of its input variable to another agent. By ceding control authority, agents can decompose coupling variables into public and private parts, which is of interest in situations of partial cooperation. In particular, sufficient conditions under which the non-existence of the maximum robust control invariant set is guaranteed are provided, expressed in terms of support functions and the dominant system eigenvalue. Finally, the results are illustrated via stable and unstable example systems with different coupling

Modelo empírico para el cálculo de los residuos generados en obras de edificiación residencial

There are numerous studies developing quantification models of construction and demolition waste (CDW) in building works. Currently, knowing the amount of CDW generated in a construction site is essential to optimize its management. Therefore, any tool, which can estimate in advance the waste generated, should be considered a strategy to propose real solutions in the field of sustainability. However, the developed models up to now, offer indicators taking into consideration only the gross floor area (GFA) of the project. In general, GFA has been widely used for CDW estimation worldwide and mainly in high density urban areas such as China or Hong Kong where dwellings are sold by GFA. However, regions such as Europe, U.S or Australia may need to consider other parameters such as the numbers of dwellings as houses are usually sold by units. Also, previous research highlight that masonry work is the main activity generating CDW. Considering this issue, the amount of waste generated during masonry works in two different projects --with the same floor area—but one designed with big surface dwellings and the other with small studios, will differ --as the latter has more brick interior partitions--. Consequently, the main aim of this research is to establish a model to estimate the waste generated, both in weight and volume, considering the GFA and the number of dwellings of the project. To do this, several construction works built in the Community of Madrid have been analyzed. The results obtained offer some formulas to know in advance the amount, both in weight and volume of the total waste that will be generated in newly built construction works. In short, the methodology developed in this paper can help to optimize and systematize the management of the CDW generated in residential construction and can help building agents in the development of CDW management Plans and Reports in agreement with the legislation in force.Existen numerosos estudios que analizan distintos modelos de cuantificación de residuos de construcción y demolición (RCD) en obras de edificación. Actualmente, es esencial conocer la cantidad de residuo generado en una obra para optimizar su gestión. Por lo tanto, cualquier herramienta que permita estimar los RCD generados en una edificación debe considerarse como una estrategia que ofrece soluciones reales en el ámbito de la sostenibilidad. Sin embargo, los modelos desarrollados hasta ahora, sólo tienen en cuenta la superficie total construida del proyecto. En general, este parámetro ha sido ampliamente utilizado para la estimación de RCD, en zonas urbanas de alta densidad, como China o Hong Kong, donde las viviendas se venden por metros cuadrados. Sin embargo, otras regiones, como Europa, Estados Unidos o Australia, deben considerar otros parámetros, como el número de viviendas ya que generalmente las viviendas se venden por unidades. Por otro lado, diversas investigaciones previas destacan que la albañilería es la actividad que más residuo genera en una obra. Teniendo en cuenta esta cuestión, la cantidad de residuo de albañilería generado en dos obras diferentes con igual superficie, pero una diseñada con grandes viviendas y la otra con pequeños estudios, diferirá pues la ejecutada con pequeños estudios generará más residuo al tener más particiones interiores. En consecuencia, el objetivo principal de esta comunicación es establecer un modelo para estimar los residuos generados, tanto en peso como en volumen, considerando la superficie total y el número de viviendas del proyecto. Para ello, se han analizado varias obras construidas en la Comunidad de Madrid. Los resultados obtenidos ofrecen dos fórmulas para estimar la cantidad, tanto en peso como volumen del RCD total generado en obras de nueva construcción. En resumen, la metodología desarrollada en esta comunicación puede ayudar a optimizar y sistematizar la gestión de los RCD generados en obras residenciales, ayudando a los agentes de la construcción en el desarrollo de los Planes y Estudios de gestión de RCD de acuerdo con la legislación vigente

Ultrasound-assisted extraction of anthocyanins and total phenolic compounds in Vitis vinifera L. 'Tempranillo' winemaking lees

Winemaking lees (WL) are the less exploited by-products from the winemaking industry. This by-product is generated after the fermentation of grape must and its composition is variable, although it is mainly made up of lysed yeasts, tartaric acid, colloids, polyphenols and ashes. Of all the compounds that can be found in lees, polyphenols exhibit particularly powerful bioactive properties and their extraction for their reuse in different matrices could be a matter of particular interest.Ultrasound-assisted extraction (UAE) has been used to extract both total anthocyanins (TA) and total phenolic compounds (TPC) from lees from Vitis vinifera L. 'Tempranillo' vinification. The optimization of six extraction variables (% methanol, pH, temperature, amplitude, cycle and ratio solvent:mass) was performed using a Box-Behnken design (BBD) where TA and TPC were considered independent variables. The UAE method that has been developed in this research could be a new rapid and efficient method to extract TPC and, coupled to chromatographic methodologies, identify up to fourteen different anthocyanins from WL. The objective of this study is to determine WL polyphenolic content and its potential for further uses in other procedures aiming to create value from vinification waste

Versatility of a Nitrogen-Containing Monolithic Porous Carbon for Lithium-Based Energy Storage

N-containing monolithic porous carbon material with dual micro and mesoporous structures was synthesized using an innovative, cheap and easy synthesis route based on the classical resorcinol-formaldehyde synthesis. A completely chemical, structural and morphological characterization was carried out. The N content in the carbonaceous material was 7.3 % and XPS data showed that is present in two different surrounds, as N-pyrrolic and N-pyridinic atoms. Is known that, the last one, can acts as a catalyst at surface level in heterogeneous reactions. In addition, using this material, we were able to fabricate lithium-ion and lithium-sulfur batteries obtaining high values of discharge capacity and cycle stability and demonstrating the multifunctional character of this carbon in energy storage devices

Oxidized multiwalled nanotubes as efficient carbocatalyst for the general synthesis of azines

The carbocatalytic synthesis of azines (N-N linked diimines) by mild-oxidized multiwalled carbon nanotubes catalyst (oxMWNT) is presented. The material, just with a 5 %wt. loading, is able to carry out a smooth room-temperature metal-free condensation of aldehydes and hydrazine, without external additives, to obtain a wide library of symmetric and also asymmetric azines in excellent yields, even in gram scale, with an excellent selectivity for aromatic substrates. This methodology allows the synthesis of azines with application in nonlinear optics, and the organic materials and biological active compounds crafting. oxMWNT catalysed the reaction in just 3 h with full recyclability upon the recovery of the catalyst. In addition, due to the inherent oxMWNT oxidative capacity in the presence of nitric acid, we have also developed the one-pot synthesis of azines starting from alcoholsFinancial support was provided by the European Research Council (ERC-CoG, Contract Number: 647550, ERC-PoC, Contract No. 861930), the Spanish Government (RTI2018-095038-B-I00), the ‘Comunidad de Madrid’ and European Structural Funds (S2018/NMT-4367) and proyectos sinérgicos I+D (Y2020/NMT6469). M.B. wishes to thank the Spanish Government for a Juan de la Cierva contract (IJC2019-042157-I