169 research outputs found

    Scottish input-output tables for 1979

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    Scotland, for the year 1973, were published in 1978, as a result of a collaborative effort between the Fraser of Allander Institute, the IBM Scientific Centre and the Scottish Council Research Institute. A second set of tables, for the year 1979, have been compiled by the Industry Department for Scotland (IDS) and the results have recently been published in a series of four special volumes. The compilation of input-output tables is a complex exercise which involves a substantial commitment of resources and time, which explains the long interval (nearly five years) between the base year of the tables and the publication of the results. The tables however reveal a great deal about the structure of the economy and have a wide range of applications. The next section of this paper explains what input-output tables are, while the following section summarises the main features of the Scottish tables for 1979. The last part of the paper outlines some applications of input-output models, and gives some examples of applications in the Scottish context

    Developing the first generally-available openEHR archetypes and templates for physiotherapy: an example of building clinical models and modelling capacity via student-led academic–industrial collaboration

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    Given the clear assertions in published literature that physiotherapy needs, and will benefit from, electronic health records, it was surprising that the international repository for clinical models for the openEHR record architecture (the Clinical Knowledge Manager or CKM at openehr.org/ckm ) made no reference to physiotherapy, and that other published modelling work had not used formalisms that provided for easy re-use. We set out to explore what would be involved in changing this

    Upgrade of the Glasgow photon tagging spectrometer for Mainz MAMI-C

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    The Glasgow photon tagging spectrometer at Mainz has been upgraded so that it can be used with the 1500 MeV electron beam now available from the Mainz microtron MAMI-C. The changes made and the resulting properties of the spectrometer are discussed.Comment: 20 pages, 12 figure

    K+ΛK^+\Lambda and K+Σ0K^+\Sigma^0 photoproduction with fine center-of-mass energy resolution

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    Measurements of γpK+Λ\gamma p \rightarrow K^{+} \Lambda and γpK+Σ0\gamma p \rightarrow K^{+} \Sigma^0 cross-sections have been obtained with the photon tagging facility and the Crystal Ball calorimeter at MAMI-C. The measurement uses a novel K+K^+ meson identification technique in which the weak decay products are characterized using the energy and timing characteristics of the energy deposit in the calorimeter, a method that has the potential to be applied at many other facilities. The fine center-of-mass energy (WW) resolution and statistical accuracy of the new data results in a significant impact on partial wave analyses aiming to better establish the excitation spectrum of the nucleon. The new analyses disfavor a strong role for quark-diquark dynamics in the nucleon.Comment: 7 pages, 8 figure

    Quasi-free photoproduction of η-mesons off 3He nuclei

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    Quasi-free photoproduction of η-mesons has been measured off nucleons bound in 3He nuclei for incident photon energies from the threshold region up to 1.4 GeV. The experiment was performed at the tagged photon facility of the Mainz MAMI accelerator with an almost 4π covering electromagnetic calorimeter, combining the TAPS and Crystal Ball detectors. The η-mesons were detected in coincidence with the recoil nucleons. This allowed a comparison of the production cross section off quasi-free protons and quasi-free neutrons and a full kinematic reconstruction of the final state, eliminating effects from nuclear Fermi motion. In the S11(1535) resonance peak, the data agree with the neutron/proton cross section ratio extracted from measurements with deuteron targets. More importantly, the prominent structure observed in photoproduction off quasi-free neutrons bound in the deuteron is also clearly observed. Its parameters (width, strength) are consistent with the expectations from the deuteron results. On an absolute scale the cross sections for both quasi-free protons and neutrons are suppressed with respect to the deuteron target pointing to significant nuclear final-state interaction effects

    The world economy [April 1979]

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    In the January issue of the Commentary is was pointed out that the mildly favourable prospects for world economic growth in 1979 were overshadowed by some political uncertainties, notably the prospect of disruptions to the supply of oil and the growth of protectionism. While the volume of world trade, as measured by the utilisation rates of dry cargo shipping, has continued to improve since the trough of June, 1978, there have been further less favourable political developments. This brief considers the impact of these developments and analyses the latest economic data

    Measurement of the transverse target and beam-target asymmetries in η\eta meson photoproduction at MAMI

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    We present new data for the transverse target asymmetry T and the very first data for the beam-target asymmetry F in the γpηp\vec \gamma \vec p\to\eta p reaction up to a center-of-mass energy of W=1.9 GeV. The data were obtained with the Crystal-Ball/TAPS detector setup at the Glasgow tagged photon facility of the Mainz Microtron MAMI. All existing model predictions fail to reproduce the new data indicating a significant impact on our understanding of the underlying dynamics of η\eta meson photoproduction. The peculiar nodal structure observed in existing T data close to threshold is not confirmed.Comment: 5 pages, 3 figures, accepted for publication in PR

    The isospin structure of photoproduction of pi-eta pairs from the nucleon in the threshold region

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    Photoproduction of πη\pi\eta-pairs from nucleons has been investigated from threshold up to incident photon energies of \approx~1.4~GeV. The quasi-free reactions γppπ0η\gamma p\rightarrow p\pi^0\eta, γnnπ0η\gamma n\rightarrow n\pi^0\eta, γpnπ+η\gamma p\rightarrow n\pi^+\eta, and γnpπη\gamma n\rightarrow p\pi^-\eta were for the first time measured from nucleons bound in the deuteron. The corresponding reactions from a free-proton target were also studied to investigate final-state interaction effects (for neutral pions the free-proton results could be compared to previous measurements; the γpnπ+η\gamma p\rightarrow n\pi^+\eta reaction was measured for the first time). For the π0η\pi^0\eta final state coherent production via the γddπ0η\gamma d\rightarrow d\pi^0\eta reaction was also investigated. The experiments were performed at the tagged photon beam of the Mainz MAMI accelerator using an almost 4π4\pi coverage electromagnetic calorimeter composed of the Crystal Ball and TAPS detectors. The total cross sections for the four different final states obey the relation σ(pπ0η)\sigma(p\pi^0\eta) \approx σ(nπ0η)\sigma(n\pi^0\eta) \approx 2σ(pπη)2\sigma(p\pi^-\eta) \approx 2σ(nπ+η)2\sigma(n\pi^+\eta) as expected for a dominant contribution from a ΔηΔ(1232)πηN\Delta^{\star}\rightarrow\eta\Delta(1232)\rightarrow\pi\eta N reaction chain, which is also supported by the shapes of the invariant-mass distributions of nucleon-meson and π\pi-η\eta pairs. The experimental results are compared to the predictions from an isobar reaction model.Comment: accepted for publication in Phys. Lett.

    T and F asymmetries in π0 photoproduction on the proton

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    The γp→π0p reaction was studied at laboratory photon energies from 425 to 1445 MeV with a transversely polarized target and a longitudinally polarized beam. The beam-target asymmetry F was measured for the first time and new high precision data for the target asymmetry T were obtained. The experiment was performed at the photon tagging facility of the Mainz Microtron (MAMI) using the Crystal Ball and TAPS photon spectrometers. The polarized cross sections were expanded in terms of associated Legendre functions and compared to recent predictions from several partial-wave analyses. The impact of the new data on our understanding of the underlying partial-wave amplitudes and baryon resonance contributions is discussed

    Measurement of the beam-helicity asymmetry II^{\odot} in the photoproduction of π0π±\pi^0\pi^{\pm}-pairs off protons and off neutrons

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    Beam-helicity asymmetries have been measured at the MAMI accelerator in Mainz for the photoproduction of mixed-charge pion pairs in the reactions γpnπ0π+\boldsymbol{\gamma}p\rightarrow n\pi^0\pi^+ off free protons and γd(p)pπ0π\boldsymbol{\gamma}d\rightarrow (p)p\pi^0\pi^- and γd(n)nπ0π+\boldsymbol{\gamma}d\rightarrow (n)n\pi^0\pi^+ off quasi-free nucleons bound in the deuteron for incident photon energies up to 1.4 GeV. Circularly polarized photons were produced from bremsstrahlung of longitudinally polarized electrons and tagged with the Glasgow-Mainz magnetic spectrometer. The charged pions, recoil protons, recoil neutrons, and decay photons from π0\pi^0 mesons were detected in the 4π\pi electromagnetic calorimeter composed of the Crystal Ball and TAPS detectors. Using a complete kinematic reconstruction of the final state, excellent agreement was found between the results for free and quasi-free protons, suggesting that the quasi-free neutron results are also a close approximation of the free-neutron asymmetries. A comparison of the results to the predictions of the Two-Pion-MAID reaction model shows that the reaction mechanisms are still not well understood, in particular at low incident photon energies in the second nucleon-resonance region.Comment: accepted for publication in Eur. phys. J.
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