Propiedades tecnológicas de la madera de Citharexylum montevidense (Spreng.) Mol. “Espina de bañado”

Citharexylum montevidense (Spreng.) Mol “Espina de bañado” es una especie nativa empleada artesanalmente en carpintería, construcciones, postes y marcos para aberturas. Sin embargo, no existen estudios tecnológicos que caractericen sus cualidades maderables, los cuales podrían permitir revalorizar su madera hacia productos de mayor valor agregado. El objetivo del presente trabajo fue determinar las propiedades físicas y mecánicas de su madera con el propósito de identificar potenciales nuevos usos. Se determinaron: contenido de humedad, densidad normal, cambios dimensionales, dureza Janka y flexión estática. La densidad (0,68 g.$latex cm^{-3}$ +/- 1208,08). De acuerdo con los valores de dureza Janka hallados, puede considerarse a la madera de Espina de bañando como semidura. Los valores obtenidos en los parámetros físico mecánicos estudiados presumen un buen comportamiento de esta madera al secado, haciéndola apta para la fabricación de pisos, aberturas y muebles.Citharexylum montevidense (Spreng.)Mol a.k.a. “Marsh Thorn” is a native species used in craft carpentry, constructions, posts and door frames. However, there are no studies that characterize technological timber qualities, which could allow wood to revalue its higher value-added products. The aim of this work was to determine the physical and mechanical features of this wood in order to identify potential new uses. Thus water content, normal density, dimensional changes, Janka hardness and static bending were determined. Density values (0.68 g.$latex cm^{-3}$+/- 1208.08). According to the values found for the Janka hardness, the wood ofCitharexylum montevidense (Spreng.) Mol is a semi-hard one. All the values obtained for both the physical and mechanical parameters of this woodletits good behavior be assumed as to the drying process which makes it suitable for the making of floors, openings, and furniture

Selective Hybridization of a Terpyridine-Based Molecule with a Noble Metal

The electronic properties of metal-molecule interfaces can in principle be controlled by molecular design and self-assembly, yielding great potential for future nano- and optoelectronic technologies. However, the coupling between molecular orbitals and the electronic states of the surface can significantly influence molecular states. In particular, molecules designed to create metal-organic self-assembled networks have functional groups that by necessity are designed to interact strongly with metals. Here, we investigate the adsorption interactions of a terpyridine (tpy)-based molecule on a noble metal, Ag(111), by low-temperature scanning tunneling microscopy (STM) and spectroscopy (STS) together with density functional theory (DFT) calculations. By comparing the local density of states (DOS) information gained from STS for the molecule on the bare Ag(111) surface with that of the molecule decoupled from the underlying metal by a NaCl bilayer, we find that tpy-localized orbitals hybridize strongly with the metal substrate. Meanwhile, those related to the phenyl rings that link the two terminal tpy groups are less influenced by the interaction with the surface. The selective hybridization of the tpy groups provides an example of strong, orbital-specific electronic coupling between a functional group and a noble-metal surface, which may alter the intended balance of interactions and resulting electronic behavior of the molecule-metal interface

Microwave assisted heterogeneous catalysis: effects of varying oxygen concentrations on the oxidative coupling of methane

The oxidative coupling of methane was investigated over alumina supported La2O3/CeO2 catalysts under microwave dielectric heating conditions at different oxygen concentrations. It was observed that, at a given temperature using microwave heating, selectivities for both ethane and ethylene were notably higher when oxygen was absent than that in oxygen/methane mixtures. The differences were attributed to the localised heating of microwave radiation resulting in temperature inhomogeneity in the catalyst bed. A simplified model was used to estimate the temperature inhomogeneity; the temperature at the centre of the catalyst bed was 85 °C greater than that at the periphery when the catalyst was heated by microwaves in a gas mixture with an oxygen concentration of 12.5% (v/v), and the temperature difference was estimated to be 168 °C in the absence of oxygen

Characterization method of dielectric properties of free falling drops in a microwave processing cavity and its application in microwave internal gelation

[EN] Microwave internal gelation (MIG) is a chemical process proposed for the production of nuclear particle fuel. The internal gelation reaction is triggered by a temperature increase of aqueous droplets falling by gravity by means of non-contact microwave heating. Due to the short residence time of a solution droplet in a microwave heating cavity, a detailed knowledge of the interaction between microwaves and chemical solution (shaped in small drops) is required. This paper describes a procedure that enables the measurement of the dielectric properties of aqueous droplets that freely fall through a microwave cavity. These measurements provide the information to determine the optimal values of the parameters (such as frequency and power) that dictate the heating of such a material under microwaves.This work is a part of the PINE (Platform for Innovative Nuclear FuEls) project which targets the development of an advanced production method for Sphere-Pac fuel and is financed by the Swiss Competence Center for Energy and Mobility. The work has been also financed by the European Commission through contract no 295664 regarding the FP7 PELGRIMM Project, as well as contract no 295825 regarding the FP7-ASGARD Project. MC-S would like to thank the ITACA research team (UPV Valencia, Spain) and the EMPA Thun (Switzerland) for their support in the measurements and Carl Beard (PSI, Switzerland) for the help provided in respect with CST simulations. The work of FLP-F was supported by the Conselleria d'Educacio of the Generalitat Valenciana for economic support (BEST/2012/010).Cabanes Sempere, M.; Catalá Civera, JM.; Penaranda-Foix, FL.; Cozzo, C.; Vaucher, S.; Pouchon, MA. (2013). Characterization method of dielectric properties of free falling drops in a microwave processing cavity and its application in microwave internal gelation. Measurement Science and Technology. 24(9). https://doi.org/10.1088/0957-0233/24/9/095009S24

Working passionately does not always pay off : the negative moderating role of passion on the relationship between deliberate practice and venture performance

Deliberate practice, an iterative process that leads to expertise, is found to be positively associated with superior performance in domains such as sports, education, and entrepreneurship. At the same time, deliberate practice is also seen as being less than enjoyable and difficult to pursue consistently. As such, passion is considered to be a vital motivator of engagement in and maintenance of deliberate practice. Despite the evident importance of passion, the relationship between passion and deliberate practice in entrepreneurship has not been subject to sufficient empirical evaluation. Therefore, in this study, we consider the way in which passion moderates the relationship between deliberate practice and venture performance. We hypothesize that deliberate practice is positively related to venture performance and that passion positively moderates this relationship. We find support for our first hypothesis, in line with previous studies. However, contrary to our second hypothesis, we find that entrepreneurial passion negatively moderates the deliberate practice-venture performance relationship. In response to this finding, we provide possible explanations as to why this negative moderation effect was observed by drawing on Kolb’s experiential learning cycle