Topologically stable gapped state in a layered superconductor

We show that a layered superconductor, described by a two-component order parameter, has a gapped state above the ground state, topologically protected from decay, containing flow and counter flow in the absence of an applied magnetic field. This state is made of skyrmions, breaks time reversal symmetry and produces a weak local magnetic field below the present threshold of detection by $\mu$SR and NMR/NQR. We estimate the density of carriers that condense into the pseudogap.Comment: 6 pages, 4 figure

Is the pseudogap a topological state?

We conjecture that the pseudogap is an inhomogeneous condensate above the homogeneous state whose existence is granted by topological stability. We consider the simplest possible order parameter theory that provides this interpretation of the pseudogap and study its angular momentum states. The normal state gap density, the breaking of the time reversal symmetry and the checkerboard pattern are naturally explained under this view. The pseudogap is a lattice of skyrmions and the inner weak local magnetic field falls below the experimental threshold of observation given by NMR/NQR and $\mu$SR experiments.Comment: 12 pages, six figures, one tabl

Modern techniques for constraint solving the CASPER experience

Dissertação apresentada para obtenção do Grau de Doutor em Engenharia Informática, pela Universidade Nova de Lisboa, Faculdade de Ciências e TecnologiaConstraint programming is a well known paradigm for addressing combinatorial problems which has enjoyed considerable success for solving many relevant industrial and academic problems. At the heart of constraint programming lies the constraint solver, a computer program which attempts to find a solution to the problem, i.e. an assignment of all the variables in the problemsuch that all the constraints are satisfied. This dissertation describes a set of techniques to be used in the implementation of a constraint solver. These techniques aim at making a constraint solver more extensible and efficient,two properties which are hard to integrate in general, and in particular within a constraint solver. Specifically, this dissertation addresses two major problems: generic incremental propagation and propagation of arbitrary decomposable constraints. For both problemswe present a set of techniques which are novel, correct, and directly concerned with extensibility and efficiency. All the material in this dissertation emerged from our work in designing and implementing a generic constraint solver. The CASPER (Constraint Solving Platformfor Engineering and Research)solver does not only act as a proof-of-concept for the presented techniques, but also served as the common test platform for the many discussed theoretical models. Besides the work related to the design and implementation of a constraint solver, this dissertation also presents the first successful application of the resulting platform for addressing an open research problem, namely finding good heuristics for efficiently directing search towards a solution

Panela’s manufacturing processes and their application to automation projects for the colombian case

La producción de panela es una actividad que ha estado presente en los hogares y en la dieta de los Colombianos desde hace muchos años tanto así que ya en épocas de la conquista, se comenzó a producir panela en pequeños trapiches artesanales con los cuales se marcó el primer acercamiento a los sistemas de producción pensados para la comercialización del producto más que para el consumo propio. De esta manera, la producción de panela se ha convertido en una de las fuentes generadoras de empleo en las zonas donde la geografía colombiana permite el cultivo de la caña de azúcar, esta área se puede estimar en aproximadamente 260.000 hectáreas con un una producción estimada de 3.8 ton/ha. Esto hace que la panela esté ubicada en un lugar importante para el producto interno bruto de la producción agroindustrial del país. No obstante lo anterior, se debe reconocer que en general, los sistemas y procesos de producción no han sido actualizados de acuerdo al comportamiento del mercado y las necesidades de la industria en el entorno actual de la industria en otros países de las mismas latitudes de Colombia.Panela’s production is an activity that has been present in homes and in the diet of Colombian people for many years as much so as in times of conquest, began to produce brown sugar in small artisanal trapiches with which marked the first approach to production systems designed for product marketing than for own consumption. Thus, panela’s production has become one of the generators of employment in areas where the Colombian geography permits the cultivation of sugarcane, this area can be estimated at approximately 260,000 hectares with an estimated production of 3.8 ton / ha. This makes the panela is located in an important gross domestic product of agribusiness production in the country instead. Nevertheless, we must be recognized that in general, processes and production systems have not been updated according to the behavior of the market and the needs of industry in the current industry environment in other countries of the same latitudes of Colombia

AGLOMERAÇÃO ESPACIAL, COOPERAÇÃO E INOVAÇÃO NA INDÚSTRIA BRASILEIRA: UMA ANÁLISE CROSS-SECTOR EXPLORATÓRIA

The article develops a cross-sector analysis in which we attempt to articulate the sector distribution of productive agglomerations in Brazilian economy with data about cooperative arrangements and innovative performance of industrial sectors, using data extracted from RAIS-MT carried out by the Ministry of Labor and from PINTEC, the innovation survey carried out by IBGE. The paper is divided into five sections. The first one describes the methodology used in the study. The second section presents an analysis of the sector distribution of the productive agglomerations in Brazilian economy. The third section presents a general view about the innovative performance of the industrial sectors, as well as a discussion about the presence of cooperative arrangements in those sectors. The forth section presents a statistical exercise in which those information are integrated in order to map different clusters of similar activities in the industrial sector. Finally, a conclusion section presents some possible implications of the analysis.

Espacios de formación y comercialización agroecológica: lecciones aprendidas en la Universidad Central del Ecuador

El artículo se enfoca en la importancia de la agroecología en el desarrollo sostenible y la necesidad de crear espacios de formación y comercialización para fomentar su producción y consumo. Se destaca la creciente demanda de productos agroecológicos y se presenta la feria agroecológica de la Universidad Central del Ecuador como un ejemplo de estos espacios. En la sección de Materiales y Métodos, se describe la metodología utilizada para analizar la feria agroecológica y se detallan los criterios de selección de los participantes y el proceso de recolección y análisis de los datos. En la sección de Resultados, se presentan los hallazgos obtenidos a partir del análisis de la feria agroecológica, destacando que es un espacio de formación y comercialización agroecológica que promueve la producción responsable y saludable, y que permite a los productores establecer relaciones directas con los consumidores