Total focussing method for volumetric imaging in immersion non destructive evaluation

This paper describes the use of a 550 (25x22) element 2MHz 2D piezoelectric composite array in immersion mode to image an aluminum test block containing a collection of artificial defects. The defects included a 1mm diameter side-drilled hole, a collection of 1mm slot defects with varying degrees of skew to the normal and a flat bottomed hole. The data collection was carried out using the full matrix capture; a scanning procedure was developed to allow the operation of the large element count array through a conventional 64-channel phased array controller. A 3D TFM algorithm capable of imaging in a dual media environment was implemented in MATLAB for the offline processing the raw scan data. This algorithm facilitates the creation of 3D images of defects while accounting for refraction effects at material boundaries. In each of the test samples interrogated the defects, and their spatial position, are readily identified using TFM. Defect directional information has been characterized using VTFM for defect exhibiting angles up to and including 45o of skew

Competitiveness Indices for Irish Manufactured Exports. Quarterly Economic Commentary Special Article, July 1981

This paper is devoted primarily to the construction of competitiveness indices for Irish manufactured exports. Our principal motivation in conducting such an exercise is the fact that no satisf a,ctory measures of competitiveness have as yet been developed for Ireland despite which the concept of competitiveness, and the problems assoicated with declining competitiveness in particular, frequently figure in public discussions of Ireland's economic performance. This concern is exemplified, for instance, by the fact that it is a recurring theme in the Quarterly Bulletins and Annual Reports of the Central Bank

Sectoral Changes in the Labour Force over the Period 1961-1980 with Particular Reference to Public Sector and Services Employment. Special Article in Quarterly Economic Commentary, Winter 2015

A knowledge of the significant changes which have been taking place in the sectoral composition of employment is fundamental to a proper understanding of the recent evolution of the labour force. This paper traces the changes in the numbers at work in broad sectors of the Irish economy over the period 1961-80. The basic information is given in Appendix I, Table A which contains an annual sectoral subdivision under four broad headings (Agriculture, Manufacturing, Building and Services); Tables 1 and lA following show these data for selected years* in this period with a somewhat more detailed sectoral subdivision, the second table giving absolute and relative employment changes by sector for the 1961/1971 and 1971/1979 periods

Sectoral Changes in the Labour Force over the Period 1961-1980 with Particular Reference to Public Sector and Services Employment. Quarterly Economic Commentary Special Article, August 1982

A knowledge of the significant changes which have been taking place in the sectoral composition of employment is fundamental to a proper understanding of the recent evolution of the labour force. This paper traces the changes in the numbers at work in broad sectors of the Irish economy over the period 1961-80. The basic information is given in Appendix I, Table A which contains an annual sectoral subdivision under four broad headings (Agriculture, Manufacturing, Building and Services); Tables 1 and 1A following show these data for selected years* in this period with a somewhat more detailed sectoral subdivision, the second table giving absolute and relative employment changes by sector for the 1961/1971 and 1971/1979 periods

Hypervelocity Stars from the Andromeda Galaxy

Hypervelocity stars (HVSs) discovered in the Milky Way (MW) halo are thought to be ejected from near the massive black hole (MBH) at the galactic centre. In this paper we investigate the spatial and velocity distributions of the HVSs which are expected to be similarly produced in the Andromeda galaxy (M31). We consider three different HVS production mechanisms: (i) the disruption of stellar binaries by the galactocentric MBH; (ii) the ejection of stars by an in-spiraling intermediate mass black hole; and (iii) the scattering of stars off a cluster of stellar-mass black holes orbiting around the MBH. While the first two mechanisms would produce large numbers of HVSs in M31, we show that the third mechanism would not be effective in M31. We numerically calculate 1.2*10^6 trajectories of HVSs from M31 within a simple model of the Local Group and hence infer the current distribution of these stars. Gravitational focusing of the HVSs by the MW and the diffuse Local Group medium leads to high densities of low mass (~ solar mass) M31 HVSs near the MW. Within the virialized MW halo, we expect there to be of order 1000 HVSs for the first mechanism and a few hundred HVSs for the second mechanism; many of these stars should have distinctively large approach velocities (< -500 km/s). In addition, we predict ~5 hypervelocity RGB stars within the M31 halo which could be identified observationally. Future MW astrometric surveys or searches for distant giants could thus find HVSs from M31.Comment: 14 pages, 6 figures, changed to match version accepted by MNRA