Magnetism of two-dimensional defects in Pd: stacking faults, twin boundaries and surfaces

Careful first-principles density functional calculations reveal the importance of hexagonal versus cubic stacking of closed packed planes of Pd as far as local magnetic properties are concerned. We find that, contrary to the stable face centered cubic phase, which is paramagnetic, the hexagonal close-packed phase of Pd is ferromagnetic with a magnetic moment of 0.35 $\mu_{B}$/atom. Our results show that two-dimensional defects with local hcp stacking, like twin boundaries and stacking faults, in the otherwise fcc Pd structure, increase the magnetic susceptibility. The (111) surface also increases the magnetic susceptibility and it becomes ferromagnetic in combination with an individual stacking fault or twin boundary close to it. On the contrary, we find that the (100) surface decreases the tendency to ferromagnetism. The results are consistent with the magnetic moment recently observed in small Pd nanoparticles, with a large surface area and a high concentration of two-dimensional stacking defects.Comment: 8 pages, 10 figure

THREE OCEAN’S BORDERS

The dossier that we present is intended to reflect on the Portuguese trio-oceanic voyage of the Renaissance centuries, not only from the perspective of the evident complexity of the encounter with other cultures, but also from that of the difficulty in understanding the plurality of observed realities. A difficult dialogue is then established, which needs time and space for assimilation and changes the idea of the world that Western thought had built over the centuries

Handling Missing Annotations for Semantic Segmentation with Deep ConvNets

International audienceAnnotation of medical images for semantic segmentation is a very time consuming and difficult task. Moreover, clinical experts often focus on specific anatomical structures and thus, produce partially annotated images. In this paper, we introduce SMILE, a new deep con-volutional neural network which addresses the issue of learning with incomplete ground truth. SMILE aims to identify ambiguous labels in order to ignore them during training, and don't propagate incorrect or noisy information. A second contribution is SMILEr which uses SMILE as initialization for automatically relabeling missing annotations, using a curriculum strategy. Experiments on 3 organ classes (liver, stomach, pancreas) show the relevance of the proposed approach for semantic seg-mentation: with 70% of missing annotations, SMILEr performs similarly as a baseline trained with complete ground truth annotations

Stability and electronic structure of M-DNA: Role of metal position

We investigate, by first-principles density-functional calculations, fragments and periodic helices of CG- and AT-DNA, modified by incorporation of Zn2+ cations. We study the relative stability of different binding sites for the metal ions as well as different methods of charge neutralization. We find that binding the Zn cation to the N(7) atom of guanine or adenine leads always to lower energies than substitution of an imino proton between two H-bonded bases. Also, neutralizing with OH- groups bonded to Zn2 + is more stable than removing protons from the phosphate groups. Contrarily to common wisdom, we find that planarity of the base pairs is not an essential factor of stability, and that nonplanar base pairs can also be stacked effectively. Finally, we find that the most stable CG and AT helices, with Zn2+ bonded to N(7) atoms and neutralized by OH- ions, have wide band gaps of more than 2 eV, and we conclude that they are poor candidates for electronic conductionThis work has been supported by Brazilian agencies: Fapemig, CNPq, and Ministerio da Ciencia e Tecnologia; by Grants FIS2009-12712, MAT2010-20843-C02-01, and CSD2007-00050 of the Spanish Ministry of Science and Innovation; and by European Grant EU(FP6-029192

Room temperature compressibility and diffusivity of liquid water from first principles.

The isothermal compressibility of water is essential to understand its anomalous properties. We compute it by ab initio molecular dynamics simulations of 200 molecules at five densities, using two different van der Waals density functionals. While both functionals predict compressibilities within ~30% of experiment, only one of them accurately reproduces, within the uncertainty of the simulation, the density dependence of the self-diffusion coefficient in the anomalous region. The discrepancies between the two functionals are explained in terms of the low- and high-density structures of the liquid

Developments in the implementation of integrated management systems

[EN] Since the emergence of standardized management systems, quality, environment, safety and health, it has experienced a continuous development of existing schemes and development of new regulations. Throughout the years, we have been looking at how companies are implementing different management systems gradually extended or tailored to their process, product and market for getting better management and underwriting policies, objectives and specific goals. This paper will give an overview of the most important management systems, seeking similarities and differences between them as well as strengths, weaknesses, and key aspects of implementation and integration.[ES] Desde la aparición los sistemas de gestión normalizados, calidad, medio ambiente, seguridad y salud, se ha vivido un continuo perfeccionamiento de los esquemas actuales así como desarrollo de normativas nuevas. A lo largo de los años hemos ido viendo como las empresas van implementando diferentes sistemas de gestión de forma paulatina, ampliados o ajustados a su proceso, producto y mercado para conseguir una mejor gestión y un aseguramiento de las políticas, objetivos y metas determinadas. En este artículo ofreceremos una visión global de los más importantes sistemas de gestión, buscando analogías y diferencias entre ellos, así como fortalezas, debilidades y aspectos claves para su implementación e integración.Gisbert Soler, V.; Bohigues Ortiz, A. (2014). Evolución en la implantación de sistemas integrados de gestión. 3C Empresa. 3(20):193-205. http://hdl.handle.net/10251/50994S19320532