42,288 research outputs found

    Active ageing – Enhancing digital literacies in elderly citizens

    Get PDF
    Being digital and information literate is crucial in nowadays society, although not every citizen has the necessary means and resources to achieve these skills, especially the elderly ones. Therefore it is necessary to develop ways to help them to enhance their digital and information competences. In this paper we will present an ongoing project that was designed and implemented with the goal to provide elderly citizens with the necessary skills of a networked society, contributing for an active ageing. The methods used were based on a set of hands on workshops delivered by a team of voluntary students and teacher, with the help of collaborators from a nursing home. The workshops were developed accordingly with the detected needs of a group of elderly citizens, based on the answers of an implemented questionnaire.info:eu-repo/semantics/publishedVersio

    Polarized antiquark flavor asymmetry: Pauli blocking vs. the pion cloud

    Full text link
    The flavor asymmetry of the unpolarized antiquark distributions in the proton, dbar(x) - ubar(x) > 0, can qualitatively be explained either by Pauli blocking by the valence quarks, or as an effect of the pion cloud of the nucleon. In contrast, predictions for the polarized asymmetry Delta_ubar(x) - Delta_dbar(x) based on rho meson contributions disagree even in sign with the Pauli blocking picture. We show that in the meson cloud picture a large positive Delta_ubar(x) - Delta_dbar(x) is obtained from pi-N - sigma-N interference-type contributions, as suggested by chiral symmetry. This effect restores the equivalence of the 'quark' and 'meson' descriptions also in the polarized case.Comment: 4 pages, revtex, 3 eps figure

    Biological effects of prolonged expoure of small animals to unusual gaseous environments semiannual report, 1 sep. 1964 - 28 feb. 1965

    Get PDF
    Biological effect of prolonged exposure of man and small animals to pure oxygen and helium - oxygen environmen

    Classical small systems coupled to finite baths

    Full text link
    We have studied the properties of a classical NSN_S-body system coupled to a bath containing NBN_B-body harmonic oscillators, employing an (NS+NB)(N_S+N_B) model which is different from most of the existing models with NS=1N_S=1. We have performed simulations for NSN_S-oscillator systems, solving 2(NS+NB)2(N_S+N_B) first-order differential equations with NS≃1−10N_S \simeq 1 - 10 and NB≃10−1000N_B \simeq 10 - 1000, in order to calculate the time-dependent energy exchange between the system and the bath. The calculated energy in the system rapidly changes while its envelope has a much slower time dependence. Detailed calculations of the stationary energy distribution of the system fS(u)f_S(u) (uu: an energy per particle in the system) have shown that its properties are mainly determined by NSN_S but weakly depend on NBN_B. The calculated fS(u)f_S(u) is analyzed with the use of the Γ\Gamma and qq-Γ\Gamma distributions: the latter is derived with the superstatistical approach (SSA) and microcanonical approach (MCA) to the nonextensive statistics, where qq stands for the entropic index. Based on analyses of our simulation results, a critical comparison is made between the SSA and MCA. Simulations have been performed also for the NSN_S-body ideal-gas system. The effect of the coupling between oscillators in the bath has been examined by additional (NS+NBN_S+N_B) models which include baths consisting of coupled linear chains with periodic and fixed-end boundary conditions.Comment: 30 pages, 16 figures; the final version accepted in Phys. Rev.

    Characterization of solar cells for space applications. Volume 1: Electrical characteristics of OCLI violet solar cells as a function of intensity and temperature

    Get PDF
    Electrical characteristics of OCLI violet N/P silicon solar cells are presented in graphical and tabular format as function of solar illumination intensity and temperature

    Laser Interferometer Gravitational-Wave Observatory beam tube component and module leak testing

    Get PDF
    Laser Interferometer Gravitational-Wave Observatory (LIGO) is a joint project of the California Institute of Technology and the Massachusetts Institute of Technology funded by the National Science Foundation. The project is designed to detect gravitational waves from astrophysical sources such as supernova and black holes. The LIGO project constructed observatories at two sites in the U.S. Each site includes two beam tubes (each 4 km long) joined to form an "L" shape. The beam tube is a 1.25 m diam 304 L stainless steel, ultrahigh vacuum tube that will operate at 1×10^–9 Torr or better. The beam tube was manufactured using a custom spiral weld tube mill from material processed to reduce the outgassing rate in order to minimize pumping costs. The integrity of the beam tube was assured by helium mass spectrometer leak testing each component of the beam tube system prior to installation. Each 2 km long, isolatable beam tube module was then leak tested after completion

    Effective target arrangement in a deterministic scale-free graph

    Full text link
    We study the random walk problem on a deterministic scale-free network, in the presence of a set of static, identical targets; due to the strong inhomogeneity of the underlying structure the mean first-passage time (MFPT), meant as a measure of transport efficiency, is expected to depend sensitively on the position of targets. We consider several spatial arrangements for targets and we calculate, mainly rigorously, the related MFPT, where the average is taken over all possible starting points and over all possible paths. For all the cases studied, the MFPT asymptotically scales like N^{theta}, being N the volume of the substrate and theta ranging from (1 - log 2/log3), for central target(s), to 1, for a single peripheral target.Comment: 8 pages, 5 figure
    • …
    corecore