The fundamental differences between Quantum Spin Hall edge-states at zig-zag and armchair terminations of honeycomb and ruby nets

Combining an analytical and numerical approach we investigate the dispersion of the topologically protected spin-filtered edge-states of the Quantum Spin Hall state on honeycomb and ruby nets with zigzag (ZZ) and armchair (AC) edges. We show that the Fermi velocity of the helical edge-states on ZZ edges increases linearly with the strength of the spin-orbit coupling (SOC) whereas for AC edges the Fermi velocity is independent of the SOC. Also the decay length of edge states into the bulk is dramatically different for AC and ZZ edges, displaying an inverse functional dependence on the SOC.Comment: 5 pages, 4 figure

Determination of screened Coulomb repulsion energies in organic molecular crystals: A real space approach

We present a general method for determining screened Coulomb parameters in molecular assemblies, in particular organic molecular crystals. This allows us to calculate the interaction parameters used in a generalized Hubbard model description of correlated organic materials. In such a model only the electrons in levels close to the Fermi level are included explicitly, while the effect of all other electrons is included as a renormalization of the model parameters. For the Coulomb integrals this renormalization is mainly due to screening. For molecular materials we can split the screening into intra- and inter-molecular screening. Here we demonstrate how the inter-molecular screening can be calculated by modeling the molecules by distributed point-polarizabilities and solving the resulting self-consistent electrostatic screening problem in real space. For the example of the quasi one-dimensional molecular metal TTF-TCNQ we demonstrate that the method gives remarkably accurate results.Comment: Submitted to Special Issue - ISCOM 2009 - Physica B Condensed Matte

Quantum critical behavior of electrons at the edge of charge order

We consider quantum critical points (QCP) in which quantum fluctuations associated with charge rather than magnetic order induce unconventional metallic properties. Based on finite-T calculations on a two-dimensional extended Hubbard model we show how the coherence scale T* characteristic of Fermi liquid behavior of the homogeneous metal vanishes at the onset of charge order. A strong effective mass enhancement reminiscent of heavy fermion behavior indicates the possible destruction of quasiparticles at the QCP. Experimental probes on quarter-filled layered organic materials are proposed for unveiling the behavior of electrons across the quantum critical region.Comment: 4 pages, 4 figures, accepted for publication in Phys. Rev. Let

Diseño de un de arco de protección en material compuesto para vehículos de competición

[ES] El presente proyecto consta de la realización de un arco de seguridad para vehículos decompetición, similar al recientemente implantado por la Federación Internacional de Automovilismo (FIA) para la Fórmula 1. Dicho componente, denominado Halo, está diseñado para soportar un impacto directo yasegurar la integridad física del piloto. El arco de protección se diseñaráen titanio y acero, como indica la norma de la FIA, con ayuda del programa SolidWorks. Una vez diseñada la pieza, se deberá comprobar si cumple con el peso, ya que cada material tiene uno diferente. Como las medidas se han querido mantener iguales para los dos materiales, primero se ha diseñado en titanio y, una vez se ha comprobado que cumple con el peso, se ha calculado para el acero. Si el acero también cumpliese, se realizará el cálculo de las tensiones producidas por las cargas de los testpara los dos materiales. Las propiedades mecánicas de los dos materiales se han obtenido con la base de datos CES Edupack. Si los dos test de cada material son superados, se efectuará un estudio estático con el material compuesto de fibra de carbono con resina epoxi. Para conocer las propiedades mecánicas del material compuesto, se ha utilizado el programa eLamX, ya que el programa SolidWorks no ha podido realizar los cálculos cuando se ha indicado el comportamiento ortotrópico del material compuesto, por lo que se considerará como isotrópico a efectos de cálculo. Si no se superasen los dos test se deberá modificar las dimensiones de la pieza hasta cumplirlos. Finalmente, se realizará un estudio aerodinámico para observarlas tensiones generadas sobre el Haloy se desarrollará un estudio económico para evaluar la viabilidad del producto diseñado.[EN] The present project aims for the design of a safety structure for racing vehicles, similar to the one recently implemented by the Fédération Internationale de l'Automobile (FIA) for Formula 1. Said component, called Halo, is designed to withstand a direct impact and ensure thephysical integrity of the race driver. The protective structure is designed in titanium and steel, as indicated by the FIA standard, using SolidWorks. Once designed in one of these two materials (titanium has been arbitrarily chosen as the starting design material), the piece is checked for compliance with weight specifications. The piece is then rebuilt in the second design material, keeping dimensions the same, and rechecked for weight specifications. If successfully passed for both materials, the piece is consequently subjected to two loading tests (for each material) and mechanical stresses are calculated. The mechanical properties of titanium and steel were obtained from the CES Edupack database. After passing loading tests, a static study iscarried out withthe piece rebuilt in carbon fiber/epoxy resin composite. eLamX software was used to know the mechanical properties of the composite material since SolidWorks could not perform the calculations when specifying the composite materialas being orthotropic. Isotropic behavior was therefore assumed for calculation purposes. Should the two tests not pass, the dimensions of the piece are modifiedand the design redone.Finally, an aerodynamic study is carried out to observe the stresses generated on the Halo,and an economic study performed to evaluate the viability of the designed product.Cano Cortés, JM. (2019). Diseño de un de arco de protección en material compuesto para vehículos de competición. http://hdl.handle.net/10251/124512TFG

Sincretismo cultural y desarrollo arquitectónico. El arte múdejar como lenguaje artístico del imperio español en la Edad Moderna

La continuidad del “moro” en el territorio cristiano cuando el movimiento de la frontera había transformado el mapa político peninsular, con la presencia en el territorio de las técnicas, los modelos y los alarifes andalusíes, determinará la creación de un nuevo imaginario artístico, el mudéjar, que con el paso del tiempo traspasará las barreras simbólicas, geográficas y físicas. El arte mudéjar alcanzó tal proyección y asimilación en la sociedad cristiana que ésta llegará a considerar, en los inicios de los tiempos modernos, los elementos decorativos y constructivos de tradición musulmana como algo propio, permeando todos los sectores sociales y alcanzando este lenguaje artístico los territorios recién conquistados por la Corona española. El Imperio desarrollará una estrategia de dominio, persuasión y propaganda a través de la utilización del arte mudéjar

Aproximaciones dogmáticas y jurisprudenciales del tipo penal de fraude de subvenciones en Colombia

Con la expedición del Estatuto Anticorrupción a través de la Ley 1474 de 2011, el sistema estatal se dispuso a generar una respuesta a los actos en contra de la Administración Pública que afectaban, además de su correcto funcionamiento, el patrimonio público y su moralidad. Una de las novedades de este Estatuto, fue la creación del delito de fraude a subvenciones, en el que se penalizaron a aquellos que obtuvieran ayudas o auxilios del Estado, sin el cumplimiento de los requisitos exigidos por la ley para acceder a este, o que los hubieran destinado a una finalidad distinta. Con esto, se han generado una serie de debates, como, por ejemplo, aquel referido a si, efectivamente con este, se pretende la protección del bien jurídico de la Administración Pública, por cuanto también se generaría una afectación al orden económico y social, bien jurídico protegido a su vez por el Código Penal. Por lo tanto, realizar un análisis dogmático y conceptual, se hace menester frente a ello, con el fin de generar debates y argumentos que permitan extraer conclusiones y posiciones particulares. Acudir a ordenamientos jurídicos extranjeros en donde la figura del fraude a subvención tenga un mayor desarrollo, como es el caso de España, será necesario para establecer comparativos y diferenciaciones entre estos dos sistemas, toda vez que, en Europa, este tipo penal data de la década de los 70 ́s. En consecuencia, este trabajo presenta una serie de aproximaciones conceptuales y jurisprudenciales sobre el tipo penal de fraude de subvenciones.With the issuance of the Anti-Corruption Statute through Law 1474 of 2011, the state system set out to generate a response to acts against the Public Administration that affected, in addition to its proper functioning, public assets and its morality. One of the novelties of this Statute was the creation of the crime of subsidy fraud, in which those who obtained aid or assistance from the State were penalized, without complying with the requirements demanded by law to access it, or who They would have been used for a different purpose. With this, a series of debates have been generated, such as, for example, the one referring to whether, effectively with this, the protection of the legal good of the Public Administration is intended, since it would also affect the economic and social order, legal right protected in turn by the Penal Code. Therefore, carrying out a dogmatic and conceptual analysis, it is necessary to face it, in order to generate debates and arguments that allow drawing conclusions and particular positions. Going to foreign legal systems where the figure of subsidy fraud has a greater development, as is the case of Spain, will be necessary to establish comparisons and differentiations between these two systems, since, in Europe, this criminal type dates from the decade of the 70's. Consequently, this work presents a series of conceptual and jurisprudential approximations on the criminal type of subsidy fraud

Polymeric Frameworks as Organic Semiconductors with Controlled Electronic Properties

The rational assembly of monomers, in principle, enables the design of a specific periodicity of polymeric frameworks, leading to a tailored set of electronic structure properties in these solid-state materials. The further development of these emerging systems requires a combination of both experimental and theoretical studies. Here, we investigated the electronic structures of two-dimensional polymeric frameworks based on triazine and benzene rings, by means of electrochemical techniques. The experimental density of states was obtained from quasi-open-circuit voltage measurements through galvanostatic intermittent titration technique, which we show to be in excellent agreement with first principles calculations performed for two and three-dimensional structures of these polymeric frameworks. These findings suggest that the electronic properties do not only depend on the number of stacked layers but also on the ratio of the different aromatic rings

Disruptive and Conventional Technologies for the Support of Logistics Processes: A Literature Review

The supply chain has become a key element of increasing the productivity and competitiveness of companies. To achieve this, it is essential to implement a strategy based on the use of technologies, which depends on knowledge of the scope and impact of logistics technologies. Therefore, this article aims to identify the main technologies supporting logistics management and supply chain processes to establish their functionality, scope, and impacts. For this, conventional technologies and technologies framed by the concept of Industry 4.0 that allow the implementation of Logistics 4.0 in companies are analyzed. As a result of searching databases such as Scopus, Web of Science, and Science Direct, we provide an analysis of 18 technologies focusing on their definition, scope, and the logistics processes involved. This study concludes that technologies in logistics management allow for a reduction in total costs, improve collaboration with suppliers and customers, increase the visibility and traceability of products and information, and support decision-making for all agents in the supply chain, including the final consumer

Metodología para la conservación del patrimonio mudéjar

Este trabajo es resultado de la investigación realizada a través de una serie de proyectos, en los que han participado especialistas de diversas disciplinas que han tenido como marco de actuación el desarrollo de estudios encaminados a la conservación del patrimonio mudéjar. Sus resultados nos permiten exponer una metodología que puede aplicarse para mejorar el mantenimiento del patrimonio artístico construido en ladrillo.This work is the result of research carried out through a series of projects, in which specialists from different disciplines have participated and whose framework for action has been the development of studies aimed at the conservation of Mudejar heritage. Its results allow us to present a methodology that can be applied to improve the maintenance of artistic heritage built in brick