818 research outputs found
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
Proton lifetime bounds from chirally symmetric lattice QCD
We present results for the matrix elements relevant for proton decay in Grand
Unified Theories (GUTs). The calculation is performed at a fixed lattice
spacing a^{-1}=1.73(3) GeV using 2+1 flavors of domain wall fermions on
lattices of size 16^3\times32 and 24^3\times64 with a fifth dimension of length
16. We use the indirect method which relies on an effective field theory
description of proton decay, where we need to estimate the low energy
constants, \alpha = -0.0112(25) GeV^3 and \beta = 0.0120(26) GeV^3. We relate
these low energy constants to the proton decay matrix elements using leading
order chiral perturbation theory. These can then be combined with experimental
bounds on the proton lifetime to bound parameters of individual GUTs.Comment: 17 pages, 9 Figure
Lattice QCD with mixed actions
We discuss some of the implications of simulating QCD when the action used
for the sea quarks is different from that used for the valence quarks. We
present exploratory results for the hadron mass spectrum and pseudoscalar meson
decay constants using improved staggered sea quarks and HYP-smeared overlap
valence quarks. We propose a method for matching the valence quark mass to the
sea quark mass and demonstrate it on UKQCD clover data in the simpler case
where the sea and valence actions are the same.Comment: 15 pages, 10 figures some minor modification to text and figures.
Accepted for publicatio
Trust, professionalism and regulation: a critical comparison of Medicine and Law
Background & Aims: Trust, professionalism and regulation are complex social phenomena, which are contextually dependent and dynamic. This project aims to explore the concept of âtrustâ in Law and Medicine - questioning what it means to be a âtrustworthyâ professional and how these understandings relate to ideas of professionalism and regulation. Methods: This study draws on a comprehensive review of the literature and interviews with thirty participants from within, or related to, the UK legal and medical professions. Participants included practitioners, those creating and implementing policy, and public representatives. Data was analysed using the âlogics approachâ from Political Discourse Theory (PDT). This helped us draw out taken-for-granted ideas and beliefs about trust, professionalism and regulation and expose these to critique. Results: Participants highly valued patient/client trust, seeing it as fundamental to the functioning of their professional âserviceâ. Trust was seen as attributed primarily to the individual practitioner and maintained through demonstrating measurable âprofessionalismâ. Practitioners were understood to be individually responsible for preserving their image as a âgood professionalâ, via evidencing their âprofessionalismâ to the patient/client and the regulator. Discussion: Current ways-of-thinking about trust permitted trust in individuals to be maintained, even when trust in the professions as a whole was challenged. However, for medical professionals particularly, this was predicated on a need to âevidenceâ that one was a âgood professionalâ through intensive and continual regulation. This created an increased dependency on a âtrust-industryâ of regulatory bodies and systems. This project critically questions how regulation shapes and impacts trust in the professions. It is a problem-driven approach, which seeks to break with current patterns of thinking and question: âwhat might be possible instead?â This opens up an ideological space and new viewpoints, whereby audiences are encouraged to consider future change
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