7,427 research outputs found

    On the motion and radiation of charged particles in strong electromagnetic waves. 1 - Motion in plane and spherical waves

    Get PDF
    Motion and radiation of charged particles in strong electromagnetic waves in plane and spherical wave

    Effect of an oxide cap layer and fluorine implantation on the metal-induced lateral crystallization of amorphous silicon

    No full text
    In this work, we investigate the effect of oxide cap layer on the metal-induced lateral crystallization (MILC) of amorphous silicon. The MILC is characterized at temperatures in the range 550 to 428°C using Nomarski optical microscopy and Raman spectroscopy. It is shown that better lateral crystallization is obtained when the oxide cap layer is omitted, with the crystallization length increasing by 33% for a 15 hour anneal at 550°C. A smaller increase of about 10% is seen at lower temperatures between 525°C and 475°C and no increase is seen below 450°C. It is also shown that the detrimental effect of the oxide cap layer can be dramatically reduced by giving samples a fluorine implant prior to the MILC anneal. Raman spectroscopy shows that random grain growth is significantly less for unimplanted samples without an oxide cap and also for fluorine implanted samples both with and without an oxide cap. The crystallization length improvement for samples without an oxide cap layer is explained by the elimination of random grain crystallization at the interface between the amorphous silicon and the oxide cap layer

    Self Similar Spherical Collapse Revisited: a Comparison between Gas and Dark Matter Dynamics

    Full text link
    We reconsider the collapse of cosmic structures in an Einstein-de Sitter Universe, using the self similar initial conditions of Fillmore & Goldreich (1984). We first derive a new approximation to describe the dark matter dynamics in spherical geometry, that we refer to the "fluid approach". This method enables us to recover the self-similarity solutions of Fillmore & Goldreich for dark matter. We derive also new self-similarity solutions for the gas. We thus compare directly gas and dark matter dynamics, focusing on the differences due to their different dimensionalities in velocity space. This work may have interesting consequences for gas and dark matter distributions in large galaxy clusters, allowing to explain why the total mass profile is always steeper than the X-ray gas profile. We discuss also the shape of the dark matter density profile found in N-body simulations in terms of a change of dimensionality in the dark matter velocity space. The stable clustering hypothesis has been finally considered in the light of this analytical approach.Comment: 14 pages, 2 figures, accepted for publication in The Astrophysical Journa

    Housing Manitoba's disabled : case studies of representative housing types

    Get PDF
    iv, 19 p

    Profiles of housing alternatives available to Manitoba's disabled

    Get PDF
    iv, 30 p

    Skeletal Rearrangements of Tetracyclic Diterpenoids

    Get PDF
    Abstract Not Provided

    Economic circumstances of Native people in selected metropolitan centres in western Canada

    Get PDF
    Report : 95 p
    corecore