title: Visco–resistive dissipation in transient reconnection driven by the Orszag–Tang vortex

authors: Armstrong, Craig Keith

subjects: Flares

abstract: Viscous effects are expected to significantly contribute to reconnective energy release mechanisms in solar flares. While simple scaling arguments based on head-on reconnection suggest that viscous dissipation may dominate resistive dissipation, it is not clear whether these findings can be applied in more general merging situations. Here we perform side-by-side planar reconnection simulations driven by the Orszag-Tang vortex, for both classical and Braginskii forms of the viscosity. This formulation has the advantage of providing an autonomous MHD system that develops strong current layers, sustained by large-scale vortical shearing flows. The dissipation rates are shown to follow analytically based scaling laws, which suggest that viscous losses generated from large-scale non-uniform velocity fields are likely to dominate resistive losses in current-sheet reconnection solutions.

text: Visco–resistive dissipation in transient reconnection driven by the Orszag–Tang vortex Viscous effects are expected to significantly contribute to reconnective energy release mechanisms in solar flares. While simple scaling arguments based on head-on reconnection suggest that viscous dissipation may dominate resistive dissipation, it is not clear whether these findings can be applied in more general merging situations. Here we perform side-by-side planar reconnection simulations driven by the Orszag-Tang vortex, for both classical and Braginskii forms of the viscosity. This formulation has the advantage of providing an autonomous MHD system that develops strong current layers, sustained by large-scale vortical shearing flows. The dissipation rates are shown to follow analytically based scaling laws, which suggest that viscous losses generated from large-scale non-uniform velocity fields are likely to dominate resistive losses in current-sheet reconnection solutions.

year: 2013

title: Selection and treatment of data for radiocarbon calibration: An update to the International Calibration (IntCal) criteria

authors: Reimer, Paula J.

abstract: High-quality data from appropriate archives are needed for the continuing improvement of radiocarbon calibration curves. We discuss here the basic assumptions behind 14C dating that necessitate calibration and the relative strengths and weaknesses of archives from which calibration data are obtained. We also highlight the procedures, problems, and uncertainties involved in determining atmospheric and surface ocean 14C/12C in these archives, including a discussion of the various methods used to derive an independent absolute timescale and uncertainty. The types of data required for the current IntCal database and calibration curve model are tabulated with examples.

text: Selection and treatment of data for radiocarbon calibration: An update to the International Calibration (IntCal) criteria High-quality data from appropriate archives are needed for the continuing improvement of radiocarbon calibration curves. We discuss here the basic assumptions behind 14C dating that necessitate calibration and the relative strengths and weaknesses of archives from which calibration data are obtained. We also highlight the procedures, problems, and uncertainties involved in determining atmospheric and surface ocean 14C/12C in these archives, including a discussion of the various methods used to derive an independent absolute timescale and uncertainty. The types of data required for the current IntCal database and calibration curve model are tabulated with examples.

year: 2013

title: An accountability model for Pakeha practitioners

authors: Huygens, Ingrid Louise Maria

subjects: Maori

abstract: This paper outlines a model of accountability for Pakeha practitioners developed over many years
as a practising community psychologist involved in research and development projects in Aotearoa
in the 1980s and 1990s, during an era of contract-funded health projects, and increasing
prominence of the Treaty of Waitangi2. The model could be termed 'transformative' in that it
reverses the usual flow of power by making the Pakeha practitioner accountable to relevant Maori
authority, and maximises the potential for new outcomes and new learning for all parties. A brief
case study is outlined where the model placed a local iwi governance structure and a national
psychiatric survivor organisation in positions of authority alongside the funder of a mental health
project. Helpful conditions, positive outcomes and barriers to transformative accountability
processes are briefly discussed.

text: An accountability model for Pakeha practitioners This paper outlines a model of accountability for Pakeha practitioners developed over many years
as a practising community psychologist involved in research and development projects in Aotearoa
in the 1980s and 1990s, during an era of contract-funded health projects, and increasing
prominence of the Treaty of Waitangi2. The model could be termed 'transformative' in that it
reverses the usual flow of power by making the Pakeha practitioner accountable to relevant Maori
authority, and maximises the potential for new outcomes and new learning for all parties. A brief
case study is outlined where the model placed a local iwi governance structure and a national
psychiatric survivor organisation in positions of authority alongside the funder of a mental health
project. Helpful conditions, positive outcomes and barriers to transformative accountability
processes are briefly discussed.

year: 1999