Lattice Boltzmann Magnetohydrodynamics

Lattice gas and lattice Boltzmann methods are recently developed numerical schemes for simulating a variety of physical systems. In this paper a new lattice Boltzmann model for modeling two-dimensional incompressible magnetohydrodynamics (MHD) is presented. The current model fully utilizes the flexibility of the lattice Boltzmann method in comparison with previous lattice gas and lattice Boltzmann MHD models, reducing the number of moving directions from $36$ in other models to $12$ only. To increase computational efficiency, a simple single time relaxation rule is used for collisions, which directly controls the transport coefficients. The bi-directional streaming process of the particle distribution function in this paper is similar to the original model [ H. Chen and W. H. Matthaeus, Phys. Rev. Lett., {\bf 58}, 1845(1987), S.Chen, H.Chen, D.Mart\'{\i}nez and W.H.Matthaeus, Phys. Rev. Lett. {\bf 67},3776 (1991)], but has been greatly simplified, affording simpler implementation of boundary conditions and increasing the feasibility of extension into a workable three-dimensional model. Analytical expressions for the transport coefficients are presented. Also, as example cases, numerical calculation for the Hartmann flow is performed, showing a good agreement between the theoreticalComment: 45 pages, to appear in Physics of Plasma

Towards a Homotopy Domain Theory

An appropriate framework is put forward for the construction of $\lambda$-models with $\infty$-groupoid structure, which we call \textit{homotopic $\lambda$-models} through the use of an $\infty$-bicategory with cartesian closure and enough points. With this, we establish the start of a project of generalization of Domain Theory and $\lambda$-calculus, in the sense that the concept of proof (path) of equality of $\lambda$-terms is raised to \textit{higher proof} (homotopy)

SWE bridge: software interface for plug & work instrument integration into marine observation platforms

7th International Workshop on Marine Technology – Martech Workshop 2016, 26-28 October 2016, Barcelona.-- 2 pages, 2 figuresThe integration of sensor systems into marine observation platforms such as gliders, cabled observatories and smart buoys requires a great deal of effort due to the diversity of architectures present in the marine acquisition systems. In the past years important steps have been taken in order to improve both standardization and interoperability, i.e. the Open Geospatial Consortium’s Sensor Web Enablement. This set of standards and protocols provide a well-defined framework to achieve standardized data chains. However a significant gap is still present in the lower-end of the data chain, between the sensor systems and the acquisition platforms. In this work a standards-based architecture to bridge this gap is proposed in order to achieve plug & work, standardized and interoperable acquisition systemsWe acknowledge the financial support from Spanish Ministerio de Economía y Competitividad under contract CGL2013- 42557-R INTMARSIS, the European Union’s NeXOS Project under contract nº 614102 and EMSODEV Project under contract n°676555Peer Reviewe

Adaptive Electrical Stimulation to Improve In-Vitro Cell Growth

AbstractAn adaptive system is used to stimulate electrically (In-Vitro) muscle vagina cells and epithelial rabbit bladder cells with external electrical stimulation ES. Waveform stimulation is synthesized from both: A specific known action potential or by a set of independent ionic potentials conforming a multi output system. Each ionic potential is the output of a set of FIR filters in which the coefficient adaptation is carried out by using a time varying step size normalized LMS (NLSM) algorithm. The adaptive system output stimulates in-vitro culture cells emulating biological neurotransmitters action. Electrical stimulation (ES) shows that cells under test grow faster than non-stimulated ones, observing bigger cell viability in stimulated cells than non stimulated. The objective of the experiment is to analyze the effect of external electrical stimulation ES on confluence and cell viability in culture cells by MTT (3-[4,5-Dimethylthiazol-2-Yl]-2,5-diphenyl-tetrazolium bromide) assays [A]

Phase stability of lanthanum orthovanadate at high-pressure

When monoclinic monazite-type LaVO4 (space group P21/n) is squeezed up to 12 GPa at room temperature, a phase transition to another monoclinic phase has been found. The structure of the high-pressure phase of LaVO4 is indexed with the same space group (P21/n), but with a larger unit-cell in which the number of atoms is doubled. The transition leads to an 8% increase in the density of LaVO4. The occurrence of such a transition has been determined by x-ray diffraction, Raman spectroscopy, and ab initio calculations. The combination of the three techniques allows us to also characterize accurately the pressure evolution of unit-cell parameters and the Raman (and IR)-active phonons of the low- and high-pressure phase. In particular, room-temperature equations of state have been determined. The changes driven by pressure in the crystal structure induce sharp modifications in the color of LaVO4 crystals, suggesting that behind the monoclinic-to-monoclinic transition there are important changes of the electronic properties of LaVO4.Comment: 39 pages, 6 tables, 7 figure

Photoacoustic characterization of phase transitions in amorphous metal alloys

In this work a pulsed laser photoacoustic technique is employed in amorphous alloys for the characterization of crystallization temperatures and the determination of the activation energies for the transitions. It is shown that the changes produced in the photoacoustic signal generated by low energy laser pulses (< 200 μJ), is a sensitive probe for detecting the crystallization of a metallic amorphous sample. A piezoelectric transducer attached to the sample by means of a glass substrate was used for the acoustic detection. The developed technique has the advantages of requiring a minimum amount of sample, with no special sample preparation or conditioning. In order to demonstrate the validity of the technique, it was applied to the study of the crystallization processes of the amorphous Mg-Zn alloy, comparing the result with respect to resistivity measurements

Smart sensing interoperability platforms in the scope of Atlantos

This paper aims to demonstrate the capabilities of a Smart Cable which aims to convert any commercial non-PUCK-enabled sensor in a Smart PUCK-enabled device. Through this development, it can be easily integrated on a sensor web platform in order to access the data in real time, and so there is no need to rely on each sensor manufacturer to comply with Sensor Web Enablement standards. The results presented in this paper were acquired during some real field experiments performed between the 24th and 28th of September at PLOCAN facilities in Gran Canaria. During these days three Turner Designs Cyclops sensors were successfully integrated and tested in a mission using an observing surface vehicle such as the Wave Glider SV-2.Peer Reviewe

Europium Underneath Graphene on Ir(111): Intercalation Mechanism, Magnetism, and Band Structure

The intercalation of Eu underneath Gr on Ir(111) is comprehensively investigated by microscopic, magnetic, and spectroscopic measurements, as well as by density functional theory. Depending on the coverage, the intercalated Eu atoms form either a $(2 \times 2)$ or a $(\sqrt{3} \times \sqrt{3})$R$30^{\circ}$ superstructure with respect to Gr. We investigate the mechanisms of Eu penetration through a nominally closed Gr sheet and measure the electronic structures and magnetic properties of the two intercalation systems. Their electronic structures are rather similar. Compared to Gr on Ir(111), the Gr bands in both systems are essentially rigidly shifted to larger binding energies resulting in n-doping. The hybridization of the Ir surface state $S_1$ with Gr states is lifted, and the moire superperiodic potential is strongly reduced. In contrast, the magnetic behavior of the two intercalation systems differs substantially as found by X-ray magnetic circular dichroism. The $(2 \times 2)$ Eu structure displays plain paramagnetic behavior, whereas for the $(\sqrt{3} \times \sqrt{3})$R$30^{\circ}$ structure the large zero-field susceptibility indicates ferromagnetic coupling, despite the absence of hysteresis at 10 K. For the latter structure, a considerable easy-plane magnetic anisotropy is observed and interpreted as shape anisotropy.Comment: 18 pages with 14 figures, including Supplemental Materia

Simulación por eventos discretos: aplicación en un proyecto de automatización industrial

Se presenta la aplicación de la simulación por eventos discretos para comprobar la viabilidad de un proyecto de automatización mediante la incorporación de robots industriales en la manufactura de cigarrillos. Se expone el contexto internacional y nacional de la robótica industrial, como una de las tecnologías habilitadoras de la industria 4.0. Luego, se describe el sistema en estudio que representa la implementación de dos robots de apoyo en el abastecimiento a las líneas de armado de la empresa. Los robots realizan la carga de rollos de determinados materiales a dos tipos de carros que luego son llevados a la línea de producción. Debido a que se trata de un sistema complejo, por la variedad de productos a procesar, la combinación de un elevado número de materiales, la programación del robot y los distintos tiempos de operación, es que se decide aplicar la simulación computacional por eventos discretos para el estudio de viabilidad. Luego del análisis de la simulación, se extraen conclusiones respecto a las estrategias abordadas en la lógica de programación de los robots, los resultados obtenidos de la simulación, y las experiencias profesionales del proyecto. El modelo fue desarrollado en Simul8, software especializado en simulación por eventos discretos.Sociedad Argentina de Informática e Investigación Operativ