Estabilidad de puentes líquidos axilsimétricos

En este trabajo se ha realizado una descripción analítica detallada de los límites de estabilidad (tanto de máximo como de mínimo volumen) de puentes líquidos axilsimétricos entre dos discos coaxiales y circulares, en ausencia de fuerzas exteriores sometidos a perturbaciones arbitrarias. Se ha obtenido una parametrización de la entrefase de las formas de equilibrio marginalmente estables, así como expresiones analíticas de los parámetros característicos de la configuración, en términos de variables elípticas. Mediante el método de Lyapunov-Schmidt, se ha descrito en detalle la bifurcación a soluciones de equilibrio en el entorno del límite de estabilidad de mínimo volumen. Se ha obtenido analíticamente la ecuación de bifurcación en el entorno de cada punto crítico, contemplándose el efecto de pequeñas perturbaciones axilsimétricas: gravedad axial, desigualdad del diámetro de los discos soporte y rotación del sistema alrededor de su eje. Se ha descrito así el comportamiento aslntótico del límite de estabilidad de mínimo volumen para pequeños valores de estas imperfecciones. Por último, se ha analizado numéricamente la estabilidad de las formas de equilibrio axilsimétricas de puentes líquidos entre discos coaxiales de diferente diámetro, en condiciones de ingravidez. Se han calculado las regiones estables para diferentes valores de la relación entre los radios de los discos, en función de los parámetros adimensionales que caracterizan la longitud y el volumen del puente. Se ha encontrado que una pequeña desigualdad en el diámetro de los discos cambia radicalmente el límite superior de estabilidad. Se han deducido relaciones entre los valores críticos de los parámetros para algunos casos particulares de especial interés en los procesos de purificación de materiales y crecimiento de monocnstales mediante el método de la zona flotante: para valores típicos del ángulo de crecimiento en materiales semiconductores y para volúmenes de líquido próximos al del cilindro de radio el radio medio de los discos

Copper-catalyzed enantioselective synthesis of β-Boron β-Amino Esters

In this report, the enantioselective, copper-catalyzed borylation of β-amidoacrylates is disclosed. A broad variety of biologically important α-aminoboronates has been prepared with consistently high levels of enantiocontrol using an inexpensive copper catalyst and a commercially available chiral ligand. The method can be applied to the synthesis of novel boron-containing dipeptides and hemiboronatesWe thank the European Research Council (ERC-337776), MINECO (CTQ2016-78779-R), National Science Foundation (1151092 and 1543699) for financial support. M. T. thanks MICINN for RyC contrac

Copper-catalyzed silylation of p-quinone methides: New entry to dibenzylic silanes

An efficient and general copper(i)-catalyzed silylation of p-quinone-methides is described. Non-symmetric dibenzylic silanes are obtained in high yields under mild reaction conditions. These compounds can be used as bench-stable benzylic carbanion precursorsWe thank the European Research Council (ERC-337776) and MINECO (CTQ2012-35957) for financial support. M. T. and A. P. thank MICINN for RyC and JdC contract

Incentives to exclusive and non-exclusive technology licensing under partial vertical integration

In this paper, we compare the scenarios of exclusive licenses and cross-licenses under the existence of partial vertical integration. To do this, a successive duopoly model is proposed, with two technology owners and two firms competing in a differentiated product market. Each technology owner has a share in one of the competing firms, so that competition is also extended to the upstream R&D sector. Thus, this model represents a mixed case to what is normally analyzed in the literature. We explore the implications of the size of innovation and the degree of vertical integration in technology diffusion. In equilibrium, patent holders’ decisions might not be aligned.The authors acknowledge financial support from the Chair GVA-UMH for the Transformation of the Economic Model

An interpolation tool for aerodynamic mesh deformation problems based on octree decomposition

Desarrollo de algoritmo de interpolación basado en descomposición octree y funciones radiales de soporte compacto para movimiento de mallas en problemas aerolástico

English Is It! (ELT Training Series) Vol. 16

The Research group From English Acquisition to English Learning and Teaching is registered at the Institute of Professional Development Teaching (IDP-ICE), at the University of Barcelona. The group, founded and led by Lourdes Montoro (September 2013 - June 2021), has involved 28 teachers and professionals. 7 of them have been members of the group, and, together with 21 guest authors, have presented their work in the publication which she also created, and coordinated to fulfill the objectives of the pedagogical project which she had devised: English Is It! (ELT Training Series (Vols. 1-16)

Development of Silane-Based Coatings with Zirconia Nanoparticles Combining Wetting, Tribological, and Aesthetical Properties

Silane-based coatings with nanoparticles have been widely used in applications related to surface protection. Between them, the improvement of corrosion resistance by increasing the hydrophobicity is one of the main research goals. However, most coatings present problems of low wear resistance and poor aesthetic appearance. Therefore, the overall goal of this research is to manufacture hydrophobic sol-gel coatings based on silanes which comply with good tribological and aesthetical properties. In the present study, stainless steel plates were coated with a silane-based solution containing zirconia nanoparticles by dip coating. Water&-ethanol solutions with silanes (methyltrimethoxysilane (MTS) and tetrathoxysilane (TEOS)) and different percentages of ZrO2 nanoparticles were prepared. Gloss, color, contact angle, surface energy, wear resistance, and thickness of coating were analyzed to elucidate the effect of zirconium oxide on the performance of the coatings. Results demonstrate that the ZrO2&-silane coatings on stainless steel offer a balanced combination of properties: low wettability, high wear resistance, and similar color and brightness compared to pristine stainless steel.This research received funding from the SUDOE project SOE1/P1/E307.The authors would like to thank to the Advanced Materials and Nanotechnology group(Mechanical Engineering Department, Universidad Pontifica Comillas-ICAI)

Insight into the copper-catalyzed borylation of strained alkenes

This document is the accepted manuscript version of a published work that appeared in final form in Synlett 2015; 26(04): 494-500, copyright © Georg Thieme Verlag Stuttgart · New York after peer review and technical editing by the publisher. To access the final online work see DOI: 10.1055/s-0034-1379882The copper-catalyzed hydro- and carboboration of strain alkenes is presented. The reaction is highly diastereoselective and affords boronic ester derivatives many of which are difficult to synthesize by known methods. Competition experiments with different alkenes show that high levels of chemoselectivity can be achieved. DFT calculations are in agreement with the observed chemoselectivityWe thank the European Research Council (ERC-337776) and MINECO (CTQ2012-35957 and CTQ2013-43698-P) for financial support. M. T. and S. D.-T thank MINECO for RyC contracts. A. P. thanks MINECO for JyC contrac

Thermal characterization and diffusivity of two mono-component epoxies for transformer insulation

The main aim of this study is the thermal characterization of an organic insulation. This insulation is a compound of two mono-component epoxy resins: Epoxylite® primer and Elmotherm® varnish. A mono-component epoxy resin usually needs a high temperature to cure; through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), non-isothermal curves are obtained, allowing the estimation of activation energies of curing and decomposition processes respectively. If Model Free Kinetic (MFK) is used from DSC curves, it is possible to simulate isothermal curves at different temperatures and times, plotting activation energy as a function of the conversion degree. The simulation from TGA curves can be used to estimate lifetime of the resins and compare them following the Toop method. DSC also allows measurement of thermal conductivity, the melting peak of metallic gallium being used for this measurement. Finally, water diffusion in resins is studied. Currently, the Materials Performance research group of UC3M is working on the European project named "Essial", where this organic insulation is used to protect the windings and the whole transformer from the environment. The results obtained will be used to determinate the optimal operating range for this insulator, demonstrating that both epoxies are required to achieve the insulating performance of the transformer and long curing times are required for full curing of Epoxylite®.This research was funded by European Union's Horizon 2020 research and innovation programme under grant agreement No 766437 (ESSIAL project)

Mesh movement strategy based on octree decomposition

The aim of the present work is to apply an interpolation method based on Radial Basis Functions(RBF) to transfer deformations from surface mesh to volume mesh in multidisciplinary CFD computations. In order to deal with the increasing need in all engineering areas to manipulate meshes of very large computational size, it is mandatory to develop methodologies based on the decomposition of the global problem into local smaller problems according to the current computational capabilities of personal computers. In this way we have applied an octree decomposition to generate computational domains where the interpolation can be easily affordable. The problem now is to develop an efficient strategy to carry out the domain decomposition, independently of mesh topology, and to lay down the influence anddependence regions for a given interpolation domain. This methodology can manage any kind of meshes, multiblock structured and unstructured, in an easy, robust and efficient way, preserving the quality of the original mesh even for very large deformations. In this work, it has been tested on inviscid and viscous meshes for aeronautical configurations. Furthermore, the methodology is suitable for parallel computations because of the inherent domain decomposition strategy