Surface magnetism in ZnO/Co3O4 mixtures

We recently reported the observation of room temperature ferromagnetism in mixtures of ZnO and Co3O4 despite the diamagnetic and antiferromagnetic character of these oxides respectively. Here we present a detailed study on the electronic structure of this material in order to account for this unexpected ferromagnetism. Electrostatic interactions between both oxides lead to a dispersion of Co3O4 particles over the surface of ZnO larger ones. As a consequence, the reduction of Co+3 to Co2+ at the particle surface takes place as evidenced by XAS measurements and optical spectrocopy. This reduction allows to xplain the observed ferromagnetic signal within the well established theories of magnetism.Comment: Accepted in Journal of Applied Physic

Recursos de la empresa y pertenencia a un sector industrial: un estudio empírico de su influencia sobre la rentabilidad empresarial

En esta investigación tratamos de analizar cuál es la importancia relativa del conjunto de factores industriales (efecto sector) frente al conjunto de características internas de las empresas (efecto empresa) en la determinación de la rentabilidad empresarial. Para ello, realizamos un análisis de componentes de la varianza, con el objetivo de confirmar o refutar los resultados obtenidos por los estudios previos, utilizando un conjunto distinto de empresas con datos más actualizados sobre su rentabilidad. En concreto, nuestra muestra está compuesta por 1453 empresas de la Comunidad Valenciana de las que se dispone de datos sobre su rentabilidad durante cinco años (1994-1998), de forma que el análisis estadístico se aplica sobre 7265 observaciones

Wide-Field Multi-Parameter FLIM: Long-Term Minimal Invasive Observation of Proteins in Living Cells.

Time-domain Fluorescence Lifetime Imaging Microscopy (FLIM) is a remarkable tool to monitor the dynamics of fluorophore-tagged protein domains inside living cells. We propose a Wide-Field Multi-Parameter FLIM method (WFMP-FLIM) aimed to monitor continuously living cells under minimum light intensity at a given illumination energy dose. A powerful data analysis technique applied to the WFMP-FLIM data sets allows to optimize the estimation accuracy of physical parameters at very low fluorescence signal levels approaching the lower bound theoretical limit. We demonstrate the efficiency of WFMP-FLIM by presenting two independent and relevant long-term experiments in cell biology: 1) FRET analysis of simultaneously recorded donor and acceptor fluorescence in living HeLa cells and 2) tracking of mitochondrial transport combined with fluorescence lifetime analysis in neuronal processes

Anabolic steroids and their effects on health: a case study of media social responsibility

Anabolic steroids are among the oldest performance- enhancing drugs in sport and their use has spread into many other layers of society. The use and sale of steroids are illegal in most parts of the world, and authorities who attempt to combat trafficking in them find themselves engaged in ceaseless, yet ultimately futile efforts: traffickers are always a step ahead of them. However, an effective way to combat steroid use could be to inform people about these drugs' advantages and disadvantages. The mainstream media can play an important part in this process. They have a social responsibility to provide exhaustive information about the long-term damage caused by these substances. Do journalists uphold this responsibility? Through a study of the headlines the Spanish press devoted to the issue between 2007 and 2011, we have examined the following question: did journalists actually inform their audience about all aspects of this public health problem? We found that they easily fall prey to sensationalism, emphasizing catchier facts to the expense of others, health-related for instance, which provides an incomplete depiction of the matter and may have harmful long-term effects, as well as going against journalism deontology

Room-Temperature Spin Transport in C60-Based Spin Valves

Carbon-based spin valves, composed of a C60 layer sandwiched between two magnetic materials show room temperature spin transport for a fullerene thickness up to 30 nm. This result, interpreted by a multistep tunnelling transport model, represents an advance in the field of carbon spintronics.Fil: Gobbi, Marco. CIC nanoGUNE Consolider; EspañaFil: Golmar, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Industrial; Argentina. CIC nanoGUNE Consolider; EspañaFil: Llopis, Roger. CIC nanoGUNE Consolider; EspañaFil: F. Casanova. CIC nanoGUNE Consolider; España. Basque Foundation for Science; EspañaFil: Hueso, Luis E.. CIC nanoGUNE Consolider; España. Basque Foundation for Science; Españ

Expanded Total Equivalent Warming Impact analysis on experimental standalone fresh-food refrigerator

The stand-alone refrigerators for fresh food storage represent a large part of supermarket refrigeration equip-ment. In these devices, the usage of refrigerants with low Global Warming Potential allows the mitigation of the direct emissions due to refrigerant leakages. In contrast, the indirect emissions in these components are highly dependent on the refrigerant charge, leakage, and equivalent emission factors related to the electricity pro-duction mix. The most used index to evaluate the environmental impact of refrigerators is the Total Equivalent Warming Impact. Despite that this index presents limits on the fixed evaluation of many parameters such as refrigerant charge, electricity consumption and, electricity emission factor. Otherwise in this study, an accurate evaluation of refrigerators emissions has been realised by using the innovative Expanded Total Equivalent Warming Impact method to an experimental stand-alone refrigerator by using a dynamic approach to evaluate direct and indirect contributions. The environmental analysis considers four different refrigerants and four different countries of location. The results show that the indirect emissions due to electricity consumption cover the highest share of emissions. In addition, the operating years affected by low refrigerant charges are respon-sible for emissions by greater than 25% compared to other ones. The hourly equivalent emissions due to elec-tricity consumption in countries characterized by an electricity generation mix mainly based on renewable and/ or nuclear plants show an indirect environmental impact up to 5 times lower than countries with a natural gas -based electricity production mix. The study also defines new strategies to reduce the environmental impact of the stand-alone refrigerator such as the use of photovoltaic systems combined with this technology or earlier maintenance processes that could determine an equivalent emission saving of up to 38%

In situ electrical characterization of palladium-based single electron transistors made by electromigration technique

We report the fabrication of single electron transistors (SETs) by feedback-controlled electromigration of palladium and palladium-nickel alloy nanowires. We have optimized a gradual electromigration process for obtaining devices consisting of three terminals (source, drain and gate electrodes), which are capacitively coupled to a metallic cluster of nanometric dimensions. This metal nanocluster forms into the inter-electrode channel during the electromigration process and constitutes the active element of each device, acting as a quantum dot that rules the electron flow between source and drain electrodes. The charge transport of the as-fabricated devices shows Coulomb blockade characteristics and the source to drain conductance can be modulated by electrostatic gating. We have thus achieved the fabrication and in situ measurement of palladium-based SETs inside a liquid helium cryostat chamber.Fil: Arzubiaga, L.. CIC nanoGUNE; EspañaFil: Golmar, Federico. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Instituto Nacional de Tecnología Industrial; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Llopis, R.. CIC nanoGUNE; EspañaFil: Casanova, F.. CIC nanoGUNE; España. IKERBASQUE; EspañaFil: Hueso, Luis E.. CIC nanoGUNE; España. IKERBASQUE; Españ