Discontinuous Molecular Dynamics for Rigid Bodies: Applications

Event-driven molecular dynamics simulations are carried out on two rigid body systems which differ in the symmetry of their molecular mass distributions. First, simulations of methane in which the molecules interact via discontinuous potentials are compared with simulations in which the molecules interact through standard continuous Lennard-Jones potentials. It is shown that under similar conditions of temperature and pressure, the rigid discontinuous molecular dynamics method reproduces the essential dynamical and structural features found in continuous-potential simulations at both gas and liquid densities. Moreover, the discontinuous molecular dynamics approach is demonstrated to be between 2 to 100 times more efficient than the standard molecular dynamics method depending on the specific conditions of the simulation. The rigid discontinuous molecular dynamics method is also applied to a discontinuous-potential model of a liquid composed of rigid benzene molecules, and equilibrium and dynamical properties are shown to be in qualitative agreement with more detailed continuous-potential models of benzene. Qualitative differences in the dynamics of the two models are related to the relatively crude treatment of variations in the repulsive interactions as one benzene molecule rotates by another.Comment: 14 pages, double column revte

Pitágoras como adivino: religión y política en la Magna Grecia.

Entre todas las facetas del filósofo griego Pitágoras de Samos, algunas de ellas aparentemente contradictorias, hay un cierto número de fuentes antiguas que lo acreditan como una gran autoridad en artes proféticas. Las actividades políticas y la influencia de su escuela en la Magna Grecia fueron también a menudo destacadas en muchos aspectos. En esta contribución nos proponemos abordar la figura de Pitágoras como adivino en la Magna Grecia preguntándonos por la posible relación entre estos dos aspectos del sabio. Por un lado, discutiremos una serie de ejemplos del poder profético de Pitágoras, analizando la evidencia literaria e iconográfi ca. Por otro lado, repasaremos las posibles implicaciones políticas de estos episodios. Si nuestra hipótesis se confirma, se podría abrir la vía para señalar cierta relación entre el arte profético tradicionalmente atribuido a Pitágoras y su supuesta influencia política, de acuerdo con un patrón de liderazgo religioso y político documentado en otros casos de la historia griega antigua.Amongst all the facets of the Greek philosopher Pythagoras of Samos, some of them seemingly contradictory, a certain number of ancient sources credited him with great authority on prophetic arts. The political activities and infl uence of his School in Magna Graecia were also often highlighted in many ways. In this contribution we intend to address the fi gure of Pythagoras as a soothsayer in Magna Graecia, in order to research the possible relation between these two aspects of his activity. On the one hand we will discuss a number of examples of Pythagoras’ prophetic power, analyzing the literary and iconographic evidence. On the other hand, we will examine the possible political implications of such function. If our hypothesis is confi rmed, we could open a research line on the interdependencies between the prophetic art traditionally ascribed to Pythagoras and his assumed political infl uence, according to a pattern of religious and political leadership attested in Ancient Greek history

Forging memory. Two works by Diener & Diener architekten in Berlin

[EN] The most distinctive feature of concrete is its ability to go from a liquid state to a stone-like state during the hardening stage. This entails moulding, restraining the liquid concrete. It is then when concrete becomes dependent on its mould, the shape, the texture, and partly on its history. To tackle two interventions in Berlin, a city with a convulsive history, the architects Diener & Diener, propose different buildings in which concrete becomes the key to link architecture to memory, to identity and to the place’s history, from a contemporary, but forward-looking perspective[ES] El rasgo más distintivo del hormigón como es su capacidad para pasar de estado líquido a pétreo durante el fraguado. Esto implica moldear, contener el hormigón fluido. Es ahí donde el hormigón se vuelve dependiente de su molde, de la forma, de la textura y también en parte de la historia de éste. Ante dos actuaciones en Berlín, una ciudad con una convulsa historia, los arquitectos Diener & Diener, plantean sendos edificios, en los que el hormigón se convierte en la clave para enlazar la arquitectura con la memoria, la identidad y la historia del lugar, desde una visión contemporánea que mira al futuro.Garcia Odiaga, I.; Begiristain Mitxelena, I. (2017). Fraguar la memoria. Dos obras de Diener & Diener Architekten en Berlín. EN BLANCO. Revista de Arquitectura. 9(22):114-122. doi:10.4995/eb.2017.7076.SWORD114122922BÜRDELIN, Markus. Precision and Madness: Swiss Made. Berlín: Hatje Cantz Publishers, 2007.Carrión MENA, Fernando. Urbicidio o la producción del olvido. Chile: Cultural Observatory, vol. 25, 2014. Available at: http://works.bepress.com/fernando_carrion/684/Hernandez MARTINEZ, Ascensión. La Clonación Arquitectónica. Madrid: Ediciones Siruela, 2007.López De La CRUZ, Juan José. Proyectos encontrados: arquitecturas de la alteración y el desvelo. Seville: Recolectores Urbanos, 2012.MARTÍNEZ GARCÍA-POSADA, Ángel. Sue-os y polvo: Cuentos de tiempo sobre arte y arquitectura. Madrid: Editorial Lampreave, 2009.PIZZA, Antonio; PLA, Maurici, Viena - Berlín: teoría, arte y arquitectura entre los siglos XIX y XX, Arquitext collection, vol. 26. Barcelona: Editorial UPC, 2002.SPEER, Albert. Memorias: Los recuerdos del Arquitecto y Ministro de Armamento de Hitler: Una crónica apasionante del tercer Reich. Barcelona: El Acantilado, 2002.SUDJIC, Deyan. La Arquitectura del poder, cómo los ricos y poderosos dan forma a nuestro mundo. Madrid: Editorial Ariel, 2007.WHITEREAD, Rachel. House. London: Phaidon, 1995

FLEXIBILITY IN HUMAN RESOURCES MANAGEMENT AND ITS IMPACT ON PERFORMANCE ORGANIZATIONS

People is the more important resource for any organization, flexibility is a highly desirable attribute for all companies; organizational flexibility is possible through people. This paper reports about the relationship between human resources management and organizational performance that can be upgraded by getting flexibility. The study was made in two main phases, first, a literature review looking for the state of the art about human resources management and organizational flexibility. Second, using affinity diagram, the relationship between these and the company performance was identified, for summarized in a conceptual proposal. The study conclude that companies can get high performance using the human resources management to be flexible

Nano-technological products in architecture and construction

This work presents a review of the scientific literature that deals with the use of nanoscience and nanotechnology in architecture and construction industry in view of letting architects, builders, real estate promoters and interested parties know the scope that various nanomaterials, existing in the construction market could be used in this activities every-day from a sustainable and durable approach to architecture and construction. As a result we present, in an orderly and classified manner, a list of nano-products that can be applied to architecture and construction in building structures, covers and installations with an approach based on the architectonic and constructive durability of each component. It is concluded that there are numerous nano-products with different uses and applications sufficient for some construction needs, with important applications such as: improvement of the durability and degradation of materials (mainly concrete and steel), the efficiency of equipment and devices such as batteries, photovoltaic cells, electrical conductors, OLED lamps, water filters, paints, sealants, windowpanes, electronical components, architectural finishes, among other products

New method for non-standard invisible particle searches in tau lepton decays

Motivated by models proposed to explain the Standard Model anomalies, and the unprecedented $\tau^{+}\tau^{-}$ data to be collected by the Belle~II experiment during the next years, we study the kinematics of tau pair decays and propose a new method to search for lepton flavor violating processes in tau lepton decays to invisible beyond Standard Model particles, such as $\tau \to \ell \alpha$, where $\ell$ is either an electron or a muon, and $\alpha$ is a massive particle that escapes undetected. The new method improves by one order of magnitude the expected upper limit on the $\tau \to \ell \alpha$ production in 3x1 prong tau decays and establishes the possibility of performing this search in 1x1 prong tau decays which has not been previously considered.Comment: 6 pages, 7 figure