1,867 research outputs found
Thyroid function in relation to bile lipids and bile acids
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SELF-RADIATION PRODUCTS FORMED FROM 3,5,3'-TRI-IODO-L-THYRONINE LABELLED WITH131I
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Density functional theory of the trapped Fermi gas in the unitary regime
We investigate a density-functional theory (DFT) approach for an unpolarized
trapped dilute Fermi gas in the unitary limit . A reformulation of the recent
work of T. Papenbrock [Phys. Rev. A, {\bf 72}, 041602(R) (2005)] in the
language of fractional exclusion statistics allows us to obtain an estimate of
the universal factor, , in three dimensions (3D), in addition to
providing a systematic treatment of finite- corrections. We show that in 3D,
finite- corrections lead to unphysical values for , thereby
suggesting that a simple DFT applied to a small number of particles may not be
suitable in 3D. We then perform an analogous calculation for the
two-dimensional (2D) system in the infinite-scattering length regime, and
obtain a value of . Owing to the unique properties of the
Thomas-Fermi energy density-functional in 2D our result, in contrast to 3D, is
{\em exact} and therefore requires no finite- corrections
Advocating for the inclusion of operatic collaborative piano curricula in higher education: Informing curricula through lived experience
The purpose of this article was to examine how the lived experiences of five professional collaborative pianists during the 35th International Hans Gabor Belvedere Singing Competition, that was held in Cape Town in 2016, could inform the inclusion of new curricula for specialised operatic collaborative piano modules in tertiary institutions. Based on the literature reviewed and themes that emerged from the data, a curriculum could include the following aspects: a knowledge of the rules of lyric diction in foreign languages; excellent sight-reading skills; knowledge of the art of orchestral reduction and repertoire; the ability to transcribe and reduce full opera scores. One personal skill that is not often developed and should also be included is the ability of a pianist to evince empathy when working with singers
Phase I and Phase II control charts for the variance and generalized variance
By extending the results of Human, Chakraborti and Smit (2010), Phase I control charts are derived for the generalized variance when the mean vector and covariance matrix of multivariate normally distributed data are unknown and estimated from m independent samples, each of size n. In Phase II predictive distributions based on a Bayesian approach are used to construct Shewart-type control limits for the variance and generalized variance. The posterior distribution is obtained by combining the likelihood (the observed data in Phase I) and the uncertainty of the unknown parameters via the prior distribution. By using the posterior distribution the unconditional predictive density functions are derived
Riemann zeros, prime numbers and fractal potentials
Using two distinct inversion techniques, the local one-dimensional potentials
for the Riemann zeros and prime number sequence are reconstructed. We establish
that both inversion techniques, when applied to the same set of levels, lead to
the same fractal potential. This provides numerical evidence that the potential
obtained by inversion of a set of energy levels is unique in one-dimension. We
also investigate the fractal properties of the reconstructed potentials and
estimate the fractal dimensions to be for the Riemann zeros and for the prime numbers. This result is somewhat surprising since the
nearest-neighbour spacings of the Riemann zeros are known to be chaotically
distributed whereas the primes obey almost poisson-like statistics. Our
findings show that the fractal dimension is dependent on both the
level-statistics and spectral rigidity, , of the energy levels.Comment: Five postscript figures included in the text. To appear in Phys. Rev.
Exact results for a charged, harmonically trapped quantum gas at arbitrary temperature and magnetic field strength
An analytical expression for the first-order density matrix of a charged,
two-dimensional, harmonically confined quantum gas, in the presence of a
constant magnetic field is derived. In contrast to previous results available
in the literature, our expressions are exact for any temperature and magnetic
field strength. We also present a novel factorization of the Bloch density
matrix in the form of a simple product with a clean separation of the
zero-field and field-dependent parts. This factorization provides an
alternative way of analytically investigating the effects of the magnetic field
on the system, and also permits the extension of our analysis to other
dimensions, and/or anisotropic confinement.Comment: To appear in Phys. Rev.
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