title: Energy dynamics in linear MHD with ion parallel viscosity

authors: Oughton, Sean

subjects: magnetohydrodynamics (MHD)

abstract: Analytic results for the time dependences of the kinetic and magnetic energies of an incompressible magneto fluid threaded by a strong uniform magnetic field B₀ are obtained. The governing equations are the linearised magnetohydrodynamic (MHD) ones, but with the conventional Laplacian dissipation replaced by ion parallel viscous effects. The behaviour is shown to depend on the relative sizes of the Alfvén frequency and the viscous and resistive dissipation rates. For many cases equipartition of the kinetic and magnetic energy holds at the (Fourier) modal level. An important exception to this behaviour occurs for two-dimensional fluctuations, that is when the wavevectors are perpendicular to B₀.

text: Energy dynamics in linear MHD with ion parallel viscosity Analytic results for the time dependences of the kinetic and magnetic energies of an incompressible magneto fluid threaded by a strong uniform magnetic field B₀ are obtained. The governing equations are the linearised magnetohydrodynamic (MHD) ones, but with the conventional Laplacian dissipation replaced by ion parallel viscous effects. The behaviour is shown to depend on the relative sizes of the Alfvén frequency and the viscous and resistive dissipation rates. For many cases equipartition of the kinetic and magnetic energy holds at the (Fourier) modal level. An important exception to this behaviour occurs for two-dimensional fluctuations, that is when the wavevectors are perpendicular to B₀.

year: 1997

title: Using task models to understand the intersection of numeracy skills and technical competence with medical device design

authors: Bowen, Judy

abstract: Task models are used in many different ways throughout the design and development of interactive systems. When the interactive systems are safety critical, task models can play an important role in ensuring system behaviours are consistent with user requirements, which may help to prevent errors. While task models can be used to describe a user’s goals and the steps required to achieve that goal, to understand where user errors may occur we also need to consider the users’ understanding of how to perform a task and how this relates to the system they are using. Our focus is on the use of medical devices such as syringe drivers and infusion pumps for intravenous medication, which forms a major part of hospital inpatient care throughout the world. While we might rely on software engineering and human factors techniques to ensure correctness of such devices, their use by medical personnel in practice includes other factors that are equally important. These include training medical personnel in the use of medical devices. Also numeracy education for medical staff to ensure that they are able to set up and perform the necessary calculations to convert prescribed medication into the appropriate values and measures for their delivery mechanisms. We have developed an approach that aims to bring together concepts of technology design (both functional correctness and usability concerns), numeracy and medication delivery competency. In order to do so we use task models as a common language that enables us to consider these different domains in a single way. We find that the ability to describe the two domains within a single process allows us to compare models of knowledge, tasks and use of devices, which can elicit potential mismatches and problems.

text: Using task models to understand the intersection of numeracy skills and technical competence with medical device design Task models are used in many different ways throughout the design and development of interactive systems. When the interactive systems are safety critical, task models can play an important role in ensuring system behaviours are consistent with user requirements, which may help to prevent errors. While task models can be used to describe a user’s goals and the steps required to achieve that goal, to understand where user errors may occur we also need to consider the users’ understanding of how to perform a task and how this relates to the system they are using. Our focus is on the use of medical devices such as syringe drivers and infusion pumps for intravenous medication, which forms a major part of hospital inpatient care throughout the world. While we might rely on software engineering and human factors techniques to ensure correctness of such devices, their use by medical personnel in practice includes other factors that are equally important. These include training medical personnel in the use of medical devices. Also numeracy education for medical staff to ensure that they are able to set up and perform the necessary calculations to convert prescribed medication into the appropriate values and measures for their delivery mechanisms. We have developed an approach that aims to bring together concepts of technology design (both functional correctness and usability concerns), numeracy and medication delivery competency. In order to do so we use task models as a common language that enables us to consider these different domains in a single way. We find that the ability to describe the two domains within a single process allows us to compare models of knowledge, tasks and use of devices, which can elicit potential mismatches and problems.

year: 2021

title: The Environmental Justice Implications of the Planning Policy and Practice of Flood Risk Management in New Zealand

authors: Martynoga, Charlotte

subjects: environmental justce

abstract: Following an international trend, the flood defence approach historically applied in New Zealand has been superseded by a shift to flood risk management, an approach that aligns with the notion of ‘living with risk’ and devolves responsibility to risk-takers at the local level. Citizens are required to assume responsibility for assessing and minimising their own exposure, increasing their resilience and adapting to periodic flooding events. Inevitably, specific communities respond differently to flooding as their capabilities to understand, identify and manage flood risk varies. Environmental justice is the framework of inquiry within which issues of power, representation and participation in planning for flood risk management are examined to consider the injustices that are experienced by communities ‘living with risk’. 

Quantitative and qualitative methods are used to investigate the extent planning is complicit in delivering flood risk management processes that can create environmentally unjust outcomes. Flood hazard maps overlaid with contextual demographic data identify who is living in at risk spaces in three case-study communities. Primary data was collected through semi-structured interviews with local government representatives and iwi, and a questionnaire to local residents was followed by interviews. 

The analysis demonstrates how the environmental justice components of distributive justice, procedural justice, justice as recognition and a capabilities approach to justice are tied together in the political and social processes of managing floods. Procedural justice is based on participatory parity so ensuring all members of the affected community are treated fairly in the deliberative and discursive decision-making is essential. Evidence revealed a community’s limited access to extensive flood risk information, unequal power sharing in decision-making and community participation, and restricted ability for disadvantaged groups to access legal processes. Distributive justice demands the use of multi-criteria analysis, rather than cost-benefit analysis, in prioritising and directing flood risk management to vulnerable communities. Using direct benefit rating to fund flood mitigation works heightens existing inequalities within communities and demands consideration of social difference in flood risk vulnerabilities. To ensure justice as recognition, local and indigenous knowledge needs to be valued and included in decision-making processes. Whilst working party arrangements are not inclusive they empower communities to be actively involved, promote trust and ownership of their local place and flood risk project. Recognition of identities and cultural practices is crucial for self-determination and minimises the marginalisation of voices. Planners need to examine social aspects of how people perceive, adapt and cope with flood risk, alongside place-based vulnerability. Policy, in embracing a capabilities approach to justice, would focus on the functionings people actually achieve rather than the opportunities. This calls for removing aggregations to look at the capabilities of individuals and communities to manage and respond to their flood risk. Judgements on planning initiatives need to be based on whether distributional outcomes enhance the capabilities of the relatively disadvantaged, thereby improving the resilience capacity of a community to manage flood risk. 

This study bridges a research gap in drawing together flood risk management, planning and environmental justice; advancing understanding of the environmental injustices within flood risk management in New Zealand.

text: The Environmental Justice Implications of the Planning Policy and Practice of Flood Risk Management in New Zealand Following an international trend, the flood defence approach historically applied in New Zealand has been superseded by a shift to flood risk management, an approach that aligns with the notion of ‘living with risk’ and devolves responsibility to risk-takers at the local level. Citizens are required to assume responsibility for assessing and minimising their own exposure, increasing their resilience and adapting to periodic flooding events. Inevitably, specific communities respond differently to flooding as their capabilities to understand, identify and manage flood risk varies. Environmental justice is the framework of inquiry within which issues of power, representation and participation in planning for flood risk management are examined to consider the injustices that are experienced by communities ‘living with risk’. 

Quantitative and qualitative methods are used to investigate the extent planning is complicit in delivering flood risk management processes that can create environmentally unjust outcomes. Flood hazard maps overlaid with contextual demographic data identify who is living in at risk spaces in three case-study communities. Primary data was collected through semi-structured interviews with local government representatives and iwi, and a questionnaire to local residents was followed by interviews. 

The analysis demonstrates how the environmental justice components of distributive justice, procedural justice, justice as recognition and a capabilities approach to justice are tied together in the political and social processes of managing floods. Procedural justice is based on participatory parity so ensuring all members of the affected community are treated fairly in the deliberative and discursive decision-making is essential. Evidence revealed a community’s limited access to extensive flood risk information, unequal power sharing in decision-making and community participation, and restricted ability for disadvantaged groups to access legal processes. Distributive justice demands the use of multi-criteria analysis, rather than cost-benefit analysis, in prioritising and directing flood risk management to vulnerable communities. Using direct benefit rating to fund flood mitigation works heightens existing inequalities within communities and demands consideration of social difference in flood risk vulnerabilities. To ensure justice as recognition, local and indigenous knowledge needs to be valued and included in decision-making processes. Whilst working party arrangements are not inclusive they empower communities to be actively involved, promote trust and ownership of their local place and flood risk project. Recognition of identities and cultural practices is crucial for self-determination and minimises the marginalisation of voices. Planners need to examine social aspects of how people perceive, adapt and cope with flood risk, alongside place-based vulnerability. Policy, in embracing a capabilities approach to justice, would focus on the functionings people actually achieve rather than the opportunities. This calls for removing aggregations to look at the capabilities of individuals and communities to manage and respond to their flood risk. Judgements on planning initiatives need to be based on whether distributional outcomes enhance the capabilities of the relatively disadvantaged, thereby improving the resilience capacity of a community to manage flood risk. 

This study bridges a research gap in drawing together flood risk management, planning and environmental justice; advancing understanding of the environmental injustices within flood risk management in New Zealand.

year: 2018