title: New Zealand regions, 1986-2001: Population dynamics

authors: Pool, Ian

subjects: fertility

abstract: New Zealand regions have markedly different population dynamics. Population change in a region is driven by three different factors: fertility, mortality and migration. A fourth factor that is often related, momentum, is analysed in a separate paper (Pool et al. forthcoming-f). The present paper analyses the degree to which the levels and impacts of these three factors differ within New Zealand. It looks at regional dynamics by analysing growth and its components, natural increase (births and deaths) and migration, both domestic and international. We first present a review of population flows, and then disaggregate these into their components; natural increase and net migration, so as to provide a demographic accounting of the factors of change. The changes are investigated for the period 1986-2001 and then for the three quinquennia of 1986-91, 1991-96 and 1996-2001.

text: New Zealand regions, 1986-2001: Population dynamics New Zealand regions have markedly different population dynamics. Population change in a region is driven by three different factors: fertility, mortality and migration. A fourth factor that is often related, momentum, is analysed in a separate paper (Pool et al. forthcoming-f). The present paper analyses the degree to which the levels and impacts of these three factors differ within New Zealand. It looks at regional dynamics by analysing growth and its components, natural increase (births and deaths) and migration, both domestic and international. We first present a review of population flows, and then disaggregate these into their components; natural increase and net migration, so as to provide a demographic accounting of the factors of change. The changes are investigated for the period 1986-2001 and then for the three quinquennia of 1986-91, 1991-96 and 1996-2001.

year: 2005-09

title: The Electrical Properties of Interfacial Double Layers

authors: Jones, Mark Hedley

subjects: Electrode modelling

abstract: When solids and liquids are brought together, interfacial double-layers are likely to form. They are too small to feel or see so their presence goes mostly unnoticed at the macroscopic level. A double layer is essentially a cluster of ions and/or charged molecules which are drawn from the body of a liquid to the surface of a solid. They are responsible for stabilising some of our most important fluids -- blood, milk, paints, and inks. Without the protection of double-layers, these mixtures clump and lose their fluidity.

This thesis examines both electricity generation from, and the electrical impedance of, interfacial double layers.  
Interfacial double-layers represent the underlying theme of this work, which is broken into two parts. In part I, double layers are used as a means of converting fluid-mechanical energy into electrical energy. My application for this is an energy harvester that could power electronic water meters. Domestic water meters are typically installed where electrical connection is not feasible. Harvesting energy at the meter may make electronic metering a feasible long-term solution. My findings show that double layer based energy harvesters are not efficient enough for this application yet. However, recent literature on the subject suggests large gains in efficiency may be possible using more exotic materials. Such gains would allow a compact harvester to generate enough energy to operate an electronic meter with wireless transmitter.

Part II models the electrical impedance of electrodes submerged in electrolytes. Double-layers contribute to the electrical impedance between solid-fluid interfaces. This work is important to designers of medical implants. Engineers use solutions of saline to mimic the environment experienced by their implants once implanted. This provides a way to test implant electronics without putting a patient at risk. A way of characterising the interface between electrodes and an electrolyte is to model it mathematically. An electrical model of an electrode-electrolyte interface was recently developed by my supervisor, Jonathan Scott. I use that model to compare electrodes placed in solutions of saline to those placed in a living animal. Measurements of the two show that no one concentration of saline matches the situation inside a live spinal cavity. I then create a low-cost electrolyte test solution that better matches the impedance measured in a living animal's spinal cavity.

text: The Electrical Properties of Interfacial Double Layers When solids and liquids are brought together, interfacial double-layers are likely to form. They are too small to feel or see so their presence goes mostly unnoticed at the macroscopic level. A double layer is essentially a cluster of ions and/or charged molecules which are drawn from the body of a liquid to the surface of a solid. They are responsible for stabilising some of our most important fluids -- blood, milk, paints, and inks. Without the protection of double-layers, these mixtures clump and lose their fluidity.

This thesis examines both electricity generation from, and the electrical impedance of, interfacial double layers.  
Interfacial double-layers represent the underlying theme of this work, which is broken into two parts. In part I, double layers are used as a means of converting fluid-mechanical energy into electrical energy. My application for this is an energy harvester that could power electronic water meters. Domestic water meters are typically installed where electrical connection is not feasible. Harvesting energy at the meter may make electronic metering a feasible long-term solution. My findings show that double layer based energy harvesters are not efficient enough for this application yet. However, recent literature on the subject suggests large gains in efficiency may be possible using more exotic materials. Such gains would allow a compact harvester to generate enough energy to operate an electronic meter with wireless transmitter.

Part II models the electrical impedance of electrodes submerged in electrolytes. Double-layers contribute to the electrical impedance between solid-fluid interfaces. This work is important to designers of medical implants. Engineers use solutions of saline to mimic the environment experienced by their implants once implanted. This provides a way to test implant electronics without putting a patient at risk. A way of characterising the interface between electrodes and an electrolyte is to model it mathematically. An electrical model of an electrode-electrolyte interface was recently developed by my supervisor, Jonathan Scott. I use that model to compare electrodes placed in solutions of saline to those placed in a living animal. Measurements of the two show that no one concentration of saline matches the situation inside a live spinal cavity. I then create a low-cost electrolyte test solution that better matches the impedance measured in a living animal's spinal cavity.

year: 2016

title: Governance of water based on responsible use – an elegant solution?‎

authors: Te Aho, Linda

abstract: The inspiration for this chapter is a proposal said to represent "a paradigm shift" for the governance of freshwater, articulated by Sir Edward Taihakurei Durie in 2014. ² Arising out of challenges to a government plan to sell its shares in powergenerating companies,³ the Durie proposal has at its heart a possibility for reconciling Maori rights and interests and wider general interests in freshwater. It is based on the assumption that Maori and the general public have a legitimate interest in the natural water regimes of the country. However, the source of the interest is not the same. The Maori interest is proprietary and is sourced in their status as the indigenous first peoples of the land who were guaranteed continuation of their tino rangatiratanga in respect of their lands and waters in Te Tiriti o Waitangi.⁴ The public interest is sourced in the British laws that superimposed Maori laws through processes of colonisation. The heart of the Durie proposal is that those utilising water for commercial purposes should be charged and that an independent commission would be responsible for overseeing charging and revenue collection and disbursement. A proportion of the funds would be allocated to Maori authorities in recognition of the Maori interest. Whether in public or Maori hands, the funds should be applied to the maintenance or improvement of the natural water bodies of the area or the assurance of water supplies to all homes. In short, the proposal focuses upon responsibility.

text: Governance of water based on responsible use – an elegant solution?‎ The inspiration for this chapter is a proposal said to represent "a paradigm shift" for the governance of freshwater, articulated by Sir Edward Taihakurei Durie in 2014. ² Arising out of challenges to a government plan to sell its shares in powergenerating companies,³ the Durie proposal has at its heart a possibility for reconciling Maori rights and interests and wider general interests in freshwater. It is based on the assumption that Maori and the general public have a legitimate interest in the natural water regimes of the country. However, the source of the interest is not the same. The Maori interest is proprietary and is sourced in their status as the indigenous first peoples of the land who were guaranteed continuation of their tino rangatiratanga in respect of their lands and waters in Te Tiriti o Waitangi.⁴ The public interest is sourced in the British laws that superimposed Maori laws through processes of colonisation. The heart of the Durie proposal is that those utilising water for commercial purposes should be charged and that an independent commission would be responsible for overseeing charging and revenue collection and disbursement. A proportion of the funds would be allocated to Maori authorities in recognition of the Maori interest. Whether in public or Maori hands, the funds should be applied to the maintenance or improvement of the natural water bodies of the area or the assurance of water supplies to all homes. In short, the proposal focuses upon responsibility.

year: 2019