33,552 research outputs found
Particle Tracking Studies Using Dynamical Map Created from Finite Element Solution of the EMMA Cell
The unconventional size and the possibility of transverse displacement of the magnets in the EMMA non-scaling FFAG motivates a careful study of particle behavior within the EMMA ring. The magnetic field map of the doublet cell is computed using a Finite Element Method solver; particle motion through the field can then be found by numerical integration, using (for example) OPERA, or ZGOUBI. However, by obtaining an analytical description of the magnetic field (by fitting a Fourier-Bessel series to the numerical data) and using a differential algebra code, such as COSY, to integrate the equations of motion, it is possible to produce a dynamical map in Taylor form. This has the advantage that, after once computing the dynamical map, multi-turn tracking is far more efficient than repeatedly performing numerical integrations. Also, the dynamical map is smaller (in terms of computer memory) than the full magnetic field map; this allows different configurations of the lattice, in terms of magnet positions, to be represented very easily using a set of dynamical maps, with interpolation between the coefficients in different maps*
A generalized bayesian inference method for constraining the interiors of super Earths and sub-Neptunes
We aim to present a generalized Bayesian inference method for constraining
interiors of super Earths and sub-Neptunes. Our methodology succeeds in
quantifying the degeneracy and correlation of structural parameters for high
dimensional parameter spaces. Specifically, we identify what constraints can be
placed on composition and thickness of core, mantle, ice, ocean, and
atmospheric layers given observations of mass, radius, and bulk refractory
abundance constraints (Fe, Mg, Si) from observations of the host star's
photospheric composition. We employed a full probabilistic Bayesian inference
analysis that formally accounts for observational and model uncertainties.
Using a Markov chain Monte Carlo technique, we computed joint and marginal
posterior probability distributions for all structural parameters of interest.
We included state-of-the-art structural models based on self-consistent
thermodynamics of core, mantle, high-pressure ice, and liquid water.
Furthermore, we tested and compared two different atmospheric models that are
tailored for modeling thick and thin atmospheres, respectively. First, we
validate our method against Neptune. Second, we apply it to synthetic
exoplanets of fixed mass and determine the effect on interior structure and
composition when (1) radius, (2) atmospheric model, (3) data uncertainties, (4)
semi-major axes, (5) atmospheric composition (i.e., a priori assumption of
enriched envelopes versus pure H/He envelopes), and (6) prior distributions are
varied. Our main conclusions are: [...]Comment: Astronomy & Astrophysics, 597, A37, 17 pages, 11 figure
Two flavors of dynamical quarks on anisotropic lattices
We report on our study of two-flavor full QCD on anisotropic lattices using
-improved Wilson quarks coupled with an RG-improved glue. The bare gauge
and quark anisotropies corresponding to the renormalized anisotropy
are determined as functions of and , which
covers the region of spatial lattice spacings --0.16 fm and
--0.9. The calibrations of the bare anisotropies are
performed with the Wilson loop and the meson dispersion relation at 4 lattice
cutoffs and 5--6 quark masses. Using the calibration results we calculate the
meson mass spectrum and the Sommer scale . We confirm that the values of
calculated for the calibration using pseudo scalar and vector meson
energy momentum dispersion relation coincide in the continuum limit within
errors. This work serves to lay ground toward studies of heavy quark systems
and thermodynamics of QCD including the extraction of the equation of state in
the continuum limit using Wilson-type quark actions.Comment: 16 pages, 23 figures, Version accepted for publication in Physical
Review
Undergraduate antimicrobial stewardship training for pharmacy students: Creating a foundation for containment of antimicrobial resistance in South Africa
To the Editor: The inappropriate and excessive use of antimicrobial
agents has cultivated the development and progression of antimicrobial
resistance worldwide, which has been recognised as a
threat to global health and safety.[1] In response to this alarming
growth in antimicrobial resistance, antimicrobial stewardship
initiatives, which aim to improve the judicious use of antimicrobial
agents, have gained global support.[2] The Antimicrobial Resistance
Strategy Framework in South Africa (SA) recognises the education of
healthcare professionals as a strategy for containment of antimicrobial
resistance in SA.[3
Perturbative renormalization factors in domain-wall QCD with improved gauge actions
We evaluate renormalization factors of the domain-wall fermion system with
various improved gauge actions at one loop level. The renormalization factors
are calculated for quark wave function, quark mass, bilinear quark operators,
three- and four-quark operators in modified minimal subtraction (MS-bar) scheme
with the dimensional reduction(DRED) as well as the naive dimensional
regularization(NDR). We also present detailed results in the mean field
improved perturbation theory.Comment: 44 page
Flavor Singlet Meson Mass in the Continuum Limit in Two-Flavor Lattice QCD
We present results for the mass of the eta-prime meson in the continuum limit
for two-flavor lattice QCD, calculated on the CP-PACS computer, using a
renormalization-group improved gauge action, and Sheikholeslami and Wohlert's
fermion action with tadpole-improved csw. Correlation functions are measured at
three values of the coupling constant beta corresponding to the lattice spacing
a approx. 0.22, 0.16, 0.11 fm and for four values of the quark mass parameter
kappa corresponding to mpi over mrho approx. 0.8, 0.75, 0.7 and 0.6. For each
beta, kappa pair, 400-800 gauge configurations are used. The two-loop diagrams
are evaluated using a noisy source method. We calculate eta-prime propagators
using local sources, and find that excited state contributions are much reduced
by smearing. A full analysis for the smeared propagators gives
metaprime=0.960(87)+0.036-0.248 GeV, in the continuum limit, where the second
error represents the systematic uncertainty coming from varying the functional
form for chiral and continuum extrapolations.Comment: 9 pages, 19 figures, 4 table
Essential micro-foundations for contemporary business operations: top management tangible competencies, relationship-based business networks and environmental sustainability
Although various studies have emphasized linkages between firm competencies, networks and sustainability at organizational level, the links between top management tangible competencies (e.g., contemporary relevant quantitative-focused education such as big data analytics and data-driven applications linked with the internet of things, relevant experience and analytical business applications), relationship-based business networks (RBNs) and environmental sustainability have not been well established at micro-level, and there is a literature gap in terms of investigating these relationships. This study examines these links based on the unique data collected from 175 top management representatives (chief executive officers and managing directors) working in food import and export firms headquartered in the UK and New Zealand. Our results from structural equation modelling indicate that top management tangible competencies (TMTCs) are the key determinants for building RBNs, mediating the correlation between TMTCs and environmental sustainability. Directly, the competencies also play a vital role towards environmental practices. The findings further depict that relationship-oriented firms perform better compared to those which focus less on such networks. Consequently, our findings provide a deeper understanding of the micro-foundations of environmental sustainability based on TMTCs rooted in the resource-based view and RBNs entrenched in the social network theory. We discuss the theoretical and practical implications of our findings, and we provide suggestions for future research
Non-visualization of lung markings below hemidiaphragm in subtle subpulmonic effusion: an old sign resuscitated
To assess the lack of visibility of vascular markings under the hemidiaphragm on a frontal chest radiograph as a sign of pleural effusion, fifteen patients were collected showing this sign. Pleural effusion was diagnosed by ultrasound, comparison with previous or subsequent chest x-ray or computed tomography. Patients in the study group exhibited this sign in the absence of the classical signs of pleural effusion. In the control group, lack of visibility of blood vessels was observed in only 4.2% cases. Non-visualization of vascular markings below the hemidiaphragm should alert the interpreter to the possible presence of pleural effusion and a lateral or decubitus view or ultrasound examination may be carried out to rule out effusion
Relativistic Quantum Games in Noninertial Frames
We study the influence of Unruh effect on quantum non-zero sum games. In
particular, we investigate the quantum Prisoners' Dilemma both for entangled
and unentangled initial states and show that the acceleration of the
noninertial frames disturbs the symmetry of the game. It is shown that for
maximally entangled initial state, the classical strategy C (cooperation)
becomes the dominant strategy. Our investigation shows that any quantum
strategy does no better for any player against the classical strategies. The
miracle move of Eisert et al (1999 Phys. Rev. Lett. 83 3077) is no more a
superior move. We show that the dilemma like situation is resolved in favor of
one player or the other.Comment: 8 Pages, 2 figures, 2 table
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