Search results for " física"
showing 10 items of 920 documents
Measurement of the inelastic proton-proton cross-section at √s = 7 TeV with the ATLAS detector
2011
The dependence of the rate of proton–proton interactions on the centre-of-mass collision energy, √s, is of fundamental importance for both hadron collider physics and particle astrophysics. The dependence cannot yet be calculated from first principles; therefore, experimental measurements are needed. Here we present the first measurement of the inelastic proton–proton interaction cross-section at a centre-of-mass energy, √s, of 7 TeV using the ATLAS detector at the Large Hadron Collider. Events are selected by requiring hits on scintillation counters mounted in the forward region of the detector. An inelastic cross-section of 60.3±2.1 mb is measured for ξ>5×10[superscript −6], where ξ is ca…
Diffraction by fractal metallic supergratings.
2007
The reflectance of corrugated surfaces with a fractal distribution of grooves is investigated. Triadic and polyadic Cantor fractal distributions are considered, and the reflected intensity is compared with that of the corresponding periodic structure. The self-similarity property of the response is analyzed when varying the depth of the grooves and the lacunarity parameter. The results confirm that the response is self-similar for the whole range of depths considered, and this property is also maintained for all values of the lacunarity parameter. © 2007 Optical Society of America. Fil: Skigin, Diana Carina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación…
Pressure-Induced Hexagonal to Monoclinic Phase Transition of Partially Hydrated CePO4
2019
We present a study of the pressure dependence of the structure of partially hydrated hexagonal CePO 4 up to 21 GPa using synchrotron powder X-ray diffraction. At a pressure of 10 GPa, a second-order structural phase transition is observed, associated with a novel polymorph. The previously unknown high-pressure phase has a monoclinic structure with a similar atomic arrangement as the low-pressure phase, but with reduced symmetry, belonging to space group C2. Group-subgroup relations hold for the space symmetry groups of both structures. There is no detectable volume discontinuity at the phase transition. Here we provide structural information on the new phase and determine the axial compress…
Magic numbers, excitation levels, and other properties of small neutral math clusters (N < 50)
2006
The ground-state energies and the radial and pair distribution functions of neutral math clusters are systematically calculated by the diffusion Monte Carlo method in steps of one math atom from 3 to 50 atoms. In addition the chemical potential and the low-lying excitation levels of each cluster are determined with high precision. These calculations reveal that the “magic numbers” observed in experimental math cluster size distributions, measured for free jet gas expansions by nondestructive matter-wave diffraction, are not caused by enhanced stabilities. Instead they are explained in terms of an enhanced growth due to sharp peaks in the equilibrium concentrations in the early part of the e…
Calculation of size‐intensive transition moments from the coupled cluster singles and doubles linear response function
1994
Coupled cluster singles and doubles linear response (CCLR) calculations have been carried out for excitation energies and dipole transition strengths for the lowest excitations in LiH, CH+, and C4and the results compared with the results from a CI-like approach to equation of motion coupled cluster (EOMCC). The transition strengths are similar in the two approaches for single molecule calculations on small systems. However, the CCLR approach gives size-intensive dipole transition strengths, while title EOMCC formalism does not. Thus, EOMCC calculations can give unphysically dipole transition strengths, e.g., in EOMCC calculations on a sequence of noninteracting LiH systems we obtained a neg…
From social stigma to family referent, boccia for a change on the way of thinking
2016
The aim of this study was to assess the impact of the practice of Boccia (adapted sport) with children aged between 4 and 14 years old with cerebral palsy in rural India and the changes that this implies in social recognition and quality of family life. This study took place between January 2015 and February 2016. The research aims to fill the knowledge gap given the little information that exists on the importance of the context, specifically in the case of a family with a disabled person. This project is part of the "Family Centred Program" and is based on the use of a structured interview called Family Quality of Life McWilliams (FaQuOL). A statistical analysis using SPSS was conducted t…
La discapacidad es trending topic: análisis del impacto en Twitter de diez campañas de sensibilización
2022
La celebración de campañas de sensibilización sobre discapacidad nace para visibilizar en la sociedad las dificultades que afrontan diariamente personas con condiciones diferentes a las de las personas de desarrollo normotípico. El objetivo del presente estudio es analizar el impacto en Twitter de diez campañas españolas sobre discapacidad, celebradas entre 2013 y 2020. Para ello, se ha utilizado Trendinalia para determinar la cantidad, posición y duración de los trending topic (TT) generados; y una herramienta de análisis de sentimientos en Twitter para determinar la valencia positiva, neutra o negativa de los tuits. Los resultados demuestran el éxito cuantitativo de las campañas en Twitte…
Sinergia colaborativa en aulas inclusivas : una experiencia de grupos interactivos con alumnado con discapacidad intelectual
2022
El presente artículo tiene por objetivo describir y analizar el proyecto Aulas Inclusivas, una experiencia de colaboración sinérgica entre el profesorado que imparte docencia a alumnado con discapacidad intelectual y el personal voluntario que participa en las asociaciones de la Federación Síndrome de Down en Castilla-La Mancha. El proyecto se fundamenta en las comunidades de aprendizaje vehiculado mediante grupos interactivos en siete centros educativos ordinarios, tanto públicos como concertados, distribuidos por las provincias del territorio castellano manchego. Con una metodología cualitativa, se han utilizado dos tipos de técnicas para la extracción de datos: una rúbrica con 15 indicad…
The implication of subcortical motor centers in voluntary human activities
2009
The main objective of the present dissertation was to analyse the subcortical implications in the preparation and execution of complex voluntary movements. Three different tasks were selected on purpose. They all are everyday activities which although functionally related have differential characteristics. The first task was the sit-to-stand manoeuvre. Simple ballistic movements are executed faster in reaction time task paradigms when the imperative signal is accompanied by a startling auditory stimulus (SAS). We examined whether this effect also occurs in complex movements such as the sit-to-stand manoeuvre, taking into account both anticipatory postural adjustments and prime movers. React…
Estudio de los trinquetes de pilota valenciana. según criterios epidemiológicos, de opinión y biomecánicos
2010
INTRODUCCIÓN La pilota valenciana es un deporte tradicional muy arraigado en la Comunidad Valenciana cuyas modalidades, escala i corda y raspall se practican en un trinquete. Sin embargo, se ha observado una problemática en los trinquetes actuales: abandono, ausencia de estudios de mejora y carencia de una normativa que establezca las características biomecánicas de los trinquetes, como resultado de la interacción entre el jugador y la pelota con el pavimento. Por otra parte, no se han encontrado investigaciones epidemiológicas en la literatura científica sobre pilota valenciana, ni estudios que relacionen la amortiguación y la fricción con la epidemiología y/o con la mejora del rendimiento…