title: Direct comparisons of compressible magnetohydrodynamics and reduced magnetohydrodynamics turbulence

authors: Oughton, Sean

subjects: mathematics

abstract: Direct numerical simulations of low Mach number compressible three-dimensional magnetohydrodynamic (CMHD3D) turbulence in the presence of a strong mean magnetic field are compared with simulations of reduced magnetohydrodynamics (RMHD). Periodic boundary conditions in the three spatial coordinates are considered. Different sets of initial conditions are chosen to explore the applicability of RMHD and to study how close the solution remains to the full compressible MHD solution as both freely evolve in time. In a first set, the initial state is prepared to satisfy the conditions assumed in the derivation of RMHD, namely, a strong mean magnetic field and plane-polarized fluctuations, varying weakly along the mean magnetic field. In those circumstances, simulations show that RMHD and CMHD3D evolve almost indistinguishably from one another. When some of the conditions are relaxed the agreement worsens but RMHD remains fairly close to CMHD3D, especially when the mean magnetic field is large enough. Moreover, the well-known spectral anisotropy effect promotes the dynamical attainment of the conditions for RMHD applicability. Global quantities (mean energies, mean-square current, and vorticity) and energy spectra from the two solutions are compared and point-to-point separation estimations are computed. The specific results shown here give support to the use of RMHD as a valid approximation of compressible MHD with a mean magnetic field under certain but quite practical conditions.

text: Direct comparisons of compressible magnetohydrodynamics and reduced magnetohydrodynamics turbulence Direct numerical simulations of low Mach number compressible three-dimensional magnetohydrodynamic (CMHD3D) turbulence in the presence of a strong mean magnetic field are compared with simulations of reduced magnetohydrodynamics (RMHD). Periodic boundary conditions in the three spatial coordinates are considered. Different sets of initial conditions are chosen to explore the applicability of RMHD and to study how close the solution remains to the full compressible MHD solution as both freely evolve in time. In a first set, the initial state is prepared to satisfy the conditions assumed in the derivation of RMHD, namely, a strong mean magnetic field and plane-polarized fluctuations, varying weakly along the mean magnetic field. In those circumstances, simulations show that RMHD and CMHD3D evolve almost indistinguishably from one another. When some of the conditions are relaxed the agreement worsens but RMHD remains fairly close to CMHD3D, especially when the mean magnetic field is large enough. Moreover, the well-known spectral anisotropy effect promotes the dynamical attainment of the conditions for RMHD applicability. Global quantities (mean energies, mean-square current, and vorticity) and energy spectra from the two solutions are compared and point-to-point separation estimations are computed. The specific results shown here give support to the use of RMHD as a valid approximation of compressible MHD with a mean magnetic field under certain but quite practical conditions.

year: 2005-11-11

title: Dancing national Identity: The evolution of meta-narratives in Colombian and Filipino Folk Dance

authors: Diaz Rodriguez, José M.

subjects: Bambuco

abstract: The Philippines and Colombia share a history of colonial conquest from the same country, Spain. This shared history has influenced the ways in which folk dance has developed. Both countries have a wide folk repertoire, some of which reflects the different ways in which Spanish source material has been processed, adapted, and fused with local material to represent ways in which the past is remembered. Despite the apparent disparity, two dances in particular, the Cariñosa in the Philippines, and the Bambuco in Colombia, share similar features in terms of their choreographic material and narratives. This article explores several meta-narratives in both sets of dances, and the politics of memory behind them, through an interdisciplinary approach, intertwining cultural representation and choreographic politics. Included in this comparative exploration are the choices towards reflecting local identities through folk dance and some of the implications of these representations in both physical and political terms.

text: Dancing national Identity: The evolution of meta-narratives in Colombian and Filipino Folk Dance The Philippines and Colombia share a history of colonial conquest from the same country, Spain. This shared history has influenced the ways in which folk dance has developed. Both countries have a wide folk repertoire, some of which reflects the different ways in which Spanish source material has been processed, adapted, and fused with local material to represent ways in which the past is remembered. Despite the apparent disparity, two dances in particular, the Cariñosa in the Philippines, and the Bambuco in Colombia, share similar features in terms of their choreographic material and narratives. This article explores several meta-narratives in both sets of dances, and the politics of memory behind them, through an interdisciplinary approach, intertwining cultural representation and choreographic politics. Included in this comparative exploration are the choices towards reflecting local identities through folk dance and some of the implications of these representations in both physical and political terms.

year: 2023-04-04

title: Maori and epilepsy: Personal perceptions of the cause, treatment and consequences of epilepsy by Maori in the Bay of Plenty

authors: Simonsen, Kiri

subjects: Maori

abstract: This paper discusses the perceptions of epilepsy held by Maori in the Bay of Plenty. The paper
begins by introducing the purpose and rationale of the research. It then moves on to describe the
aims and qualitative research methods that were used to collect the data. Finally the paper
discusses the findings of the research, this includes: a close look at the unique perceptions of
epilepsy that were reported by Maori in the Bay of Plenty; the lack of resources and services
available in a small rural town of the Bay of Plenty; the services desired by Maori; attitudes
towards medication and the inappropriate behaviour many of the participants experienced by the
medical profession.

text: Maori and epilepsy: Personal perceptions of the cause, treatment and consequences of epilepsy by Maori in the Bay of Plenty This paper discusses the perceptions of epilepsy held by Maori in the Bay of Plenty. The paper
begins by introducing the purpose and rationale of the research. It then moves on to describe the
aims and qualitative research methods that were used to collect the data. Finally the paper
discusses the findings of the research, this includes: a close look at the unique perceptions of
epilepsy that were reported by Maori in the Bay of Plenty; the lack of resources and services
available in a small rural town of the Bay of Plenty; the services desired by Maori; attitudes
towards medication and the inappropriate behaviour many of the participants experienced by the
medical profession.

year: 1999