title: Phenomenology for the decay of energy-containing eddies in homogeneous MHD turbulence

authors: Hossain, Murshed

subjects: magnetohydrodynamics (MHD)

abstract: We evaluate a number of simple, one‐point phenomenological models for the decay of energy‐containing eddies in magnetohydrodynamic(MHD) and hydrodynamicturbulence. The MHDmodels include effects of cross helicity and Alfvénic couplings associated with a constant mean magnetic field, based on physical effects well‐described in the literature. The analytic structure of three separate MHDmodels is discussed. The single hydrodynamic model and several MHDmodels are compared against results from spectral‐method simulations. The hydrodynamic model phenomenology has been previously verified against experiments in wind tunnels, and certain experimentally determined parameters in the model are satisfactorily reproduced by the present simulation. This agreement supports the suitability of our numerical calculations for examining MHDturbulence, where practical difficulties make it more difficult to study physical examples. When the triple‐decorrelation time and effects of spectral anisotropy are properly taken into account, particular MHDmodels give decay rates that remain correct to within a factor of 2 for several energy‐halving times. A simple model of this type is likely to be useful in a number of applications in space physics, astrophysics, and laboratory plasma physics where the approximate effects of turbulence need to be included.

text: Phenomenology for the decay of energy-containing eddies in homogeneous MHD turbulence We evaluate a number of simple, one‐point phenomenological models for the decay of energy‐containing eddies in magnetohydrodynamic(MHD) and hydrodynamicturbulence. The MHDmodels include effects of cross helicity and Alfvénic couplings associated with a constant mean magnetic field, based on physical effects well‐described in the literature. The analytic structure of three separate MHDmodels is discussed. The single hydrodynamic model and several MHDmodels are compared against results from spectral‐method simulations. The hydrodynamic model phenomenology has been previously verified against experiments in wind tunnels, and certain experimentally determined parameters in the model are satisfactorily reproduced by the present simulation. This agreement supports the suitability of our numerical calculations for examining MHDturbulence, where practical difficulties make it more difficult to study physical examples. When the triple‐decorrelation time and effects of spectral anisotropy are properly taken into account, particular MHDmodels give decay rates that remain correct to within a factor of 2 for several energy‐halving times. A simple model of this type is likely to be useful in a number of applications in space physics, astrophysics, and laboratory plasma physics where the approximate effects of turbulence need to be included.

year: 1995

title: Ahamb (Malekula, Vanuatu) - Language Contexts

authors: Rangelov, Tihomir

subjects: Ahamb language

abstract: The Ahamb language is spoken by around 950 people, most of whom reside on the small Ahamb Island off the south coast of Malekula, the second largest island in the Republic of Vanuatu in the South Pacific. Ahamb is one of more than 30 languages of Malekula, and little was known about it until 2017 when a major language documentation project was initiated. In this paper we present the linguistic, geographic and social context in which Ahamb is spoken, assess its current vitality status, and consider prospects for its future. It is hoped that outputs of the Ahamb Documentation Project will boost the status of the language and increase literacy levels, counteracting external pressures to shift to the regional lingua franca Bislama.

text: Ahamb (Malekula, Vanuatu) - Language Contexts The Ahamb language is spoken by around 950 people, most of whom reside on the small Ahamb Island off the south coast of Malekula, the second largest island in the Republic of Vanuatu in the South Pacific. Ahamb is one of more than 30 languages of Malekula, and little was known about it until 2017 when a major language documentation project was initiated. In this paper we present the linguistic, geographic and social context in which Ahamb is spoken, assess its current vitality status, and consider prospects for its future. It is hoped that outputs of the Ahamb Documentation Project will boost the status of the language and increase literacy levels, counteracting external pressures to shift to the regional lingua franca Bislama.

year: 2019

title: New Zealand regions, 1986 – 2001: Hospitalisation and some related health facts

authors: Pool, Ian

subjects: health

abstract: Once age and gender composition is controlled for, regional health differentials are a function of problems of health service delivery, of socio-economic variance, and overall Māori Pakeha health differences. They indicate relative levels of exclusion and of inequality. This paper shows that these differentials follow in general the patterns seen in other papers in this series.

text: New Zealand regions, 1986 – 2001: Hospitalisation and some related health facts Once age and gender composition is controlled for, regional health differentials are a function of problems of health service delivery, of socio-economic variance, and overall Māori Pakeha health differences. They indicate relative levels of exclusion and of inequality. This paper shows that these differentials follow in general the patterns seen in other papers in this series.

year: 2006-03