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: "Experiences of families and professionals living/interacting with neurodivergent children while navigating the policy contexts of health, education and social services: The fight for accessible and suitable support"

authors: Robyns, Kelly Louise

subjects: Neurodivergent

abstract: Families of neurodivergent children often end up interacting with policy contexts of health, education, and social services on a regular basis when they have unmet needs. My research investigates these policy contexts to better understand how more accessible and suitable support can be provided to meet those needs. My research also describes the experiences of families that struggle to find or receive accessible and suitable support. I also aimed to highlight the principles of the neurodiversity paradigm to illustrate the deficit-based thinking of current systems and practice. It is natural, healthy, and valuable to have diversity among minds, both in the classroom and in society. The principles of the neurodiversity paradigm challenge the ways in which health, education, and social service systems respond to neurodivergent children. My research design included literature review, policy analysis, key informant interviews and autoethnographic reflections. Literature was drawn from academic research, but grey literature was particularly important as sometimes families of neurodivergent children at crisis point feel that they had no choice but to talk to the media. I also undertook interviews with social service professionals locally to understand their position on New Zealand provision for neurodivergent children and their families. My findings indicate that there are key limitations and problems in relation to current policy and practice. There is tension between the policy emphasis of inclusion and the real-life experiences that document the practice of exclusion. This could be due to the ways in which neurodivergent children are constructed and framed through policy language that reflects a deficit-thinking model. To ensure that the needs of neurodivergent children are met through the paradigm of neurodiversity more professional development and policy language shifts need to occur so that society can see neurological differences as a valuable part of humanity. Furthermore, greater emphasis needs to be placed on options that are accessible for families, and suitable to the unique needs of their children. Overall, the research also demonstrates that much higher levels of transparency is needed between the siloed policy areas of health, education and social services, the professionals who work in each of these areas and most importantly between clinicians and families in relation to diagnoses, funding, and physical support. Finally, there also needs to be transparency in terms of the objectives of the neurodiversity paradigm which is to make clear the faults of the system and accept difference as the norm. The neurodiversity movement and paradigm challenge the deficit-based pathological views of neurological differences such as autism, ADHD, epilepsy and other neurodivergences. When neurodivergence is pathologized neurodivergent people are compared to a fictional norm or a ‘right’ way of being resulting in stigma, shame and often co-occurring mental health conditions such as anxiety and depression. These findings are important as families of neurodivergent children with unmet needs are forced to interact with policy contexts to receive support and funding. Accessible, suitable support including funding availability is essential to a neurodivergent child’s well-being and inclusion within society.

text: "Experiences of families and professionals living/interacting with neurodivergent children while navigating the policy contexts of health, education and social services: The fight for accessible and suitable support" Families of neurodivergent children often end up interacting with policy contexts of health, education, and social services on a regular basis when they have unmet needs. My research investigates these policy contexts to better understand how more accessible and suitable support can be provided to meet those needs. My research also describes the experiences of families that struggle to find or receive accessible and suitable support. I also aimed to highlight the principles of the neurodiversity paradigm to illustrate the deficit-based thinking of current systems and practice. It is natural, healthy, and valuable to have diversity among minds, both in the classroom and in society. The principles of the neurodiversity paradigm challenge the ways in which health, education, and social service systems respond to neurodivergent children. My research design included literature review, policy analysis, key informant interviews and autoethnographic reflections. Literature was drawn from academic research, but grey literature was particularly important as sometimes families of neurodivergent children at crisis point feel that they had no choice but to talk to the media. I also undertook interviews with social service professionals locally to understand their position on New Zealand provision for neurodivergent children and their families. My findings indicate that there are key limitations and problems in relation to current policy and practice. There is tension between the policy emphasis of inclusion and the real-life experiences that document the practice of exclusion. This could be due to the ways in which neurodivergent children are constructed and framed through policy language that reflects a deficit-thinking model. To ensure that the needs of neurodivergent children are met through the paradigm of neurodiversity more professional development and policy language shifts need to occur so that society can see neurological differences as a valuable part of humanity. Furthermore, greater emphasis needs to be placed on options that are accessible for families, and suitable to the unique needs of their children. Overall, the research also demonstrates that much higher levels of transparency is needed between the siloed policy areas of health, education and social services, the professionals who work in each of these areas and most importantly between clinicians and families in relation to diagnoses, funding, and physical support. Finally, there also needs to be transparency in terms of the objectives of the neurodiversity paradigm which is to make clear the faults of the system and accept difference as the norm. The neurodiversity movement and paradigm challenge the deficit-based pathological views of neurological differences such as autism, ADHD, epilepsy and other neurodivergences. When neurodivergence is pathologized neurodivergent people are compared to a fictional norm or a ‘right’ way of being resulting in stigma, shame and often co-occurring mental health conditions such as anxiety and depression. These findings are important as families of neurodivergent children with unmet needs are forced to interact with policy contexts to receive support and funding. Accessible, suitable support including funding availability is essential to a neurodivergent child’s well-being and inclusion within society.

year: 2023

title: Maori at Te Aroha after the opening of the goldfield in 1880 (mostly through Pakeha eyes)

authors: Hart, Philip

abstract: As the Maori population continued to decline, the aged rangatira admired by Pakeha (even including those who had fought against the Crown) gradually died off, to be replaced by Maori more noted for their drinking and occasional violence than their prestige. Although concerts and haka were popular with many Pakeha, much Maori behaviour was mocked, including by children. Many Maori were seen as being unsophisticated, unable to express themselves properly in English, and prone to drunkenness and laziness, whereas those who adopted Pakeha ways were praised.
Some Pakeha sympathized with poverty-stricken Maori and regretted the decline of their language. There were many examples of close and friendly relations and of Maori assisting Pakeha in trouble, but in general they lived geographically separate lives. To earn money, Maori were forced to work at road making, timber cutting, gum digging, and farming what land remained in their possession. Most Maori struggled financially, their limited resources being stretched by holding expensive tangi and entertaining visitors – resulting in more land sales. They used the court system to defend their economic interests.
Ngati Rahiri (including supporters of the Kingitanga) were seen as ‘loyal’ to the Crown, and visiting Maori kings received kindly treatment from Pakeha as well as from Maori. 
Poor health prompted some government assistance, but poor housing remained, although some attempts were made to improve it (partly to protect Pakeha from diseases). Before the twentieth century only a few children, mostly ‘half-castes’, were educated. Most Ngati Rahiri were members of the Church of England before being attracted by the new Mormon faith.
Ngati Rahiri participated with Pakeha in horse races, sporting contests, and, especially, rugby, and a few joined the Volunteers. Much less desirable to most residents was their heavy drinking (encouraged by some publicans and their Pakeha drinking buddies), and occasional fights, very occasionally with Pakeha. Overall, Pakeha ways, both good and bad, of necessity were adopted, and Ngati Rahiri became inextricably a subordinate part of the Pakeha community, although still retaining some distinctive features. 

 (Note: Unless otherwise indicated, all those named in this paper, both Maori and Pakeha, were shareholders in claims in the Te Aroha district.)

text: Maori at Te Aroha after the opening of the goldfield in 1880 (mostly through Pakeha eyes) As the Maori population continued to decline, the aged rangatira admired by Pakeha (even including those who had fought against the Crown) gradually died off, to be replaced by Maori more noted for their drinking and occasional violence than their prestige. Although concerts and haka were popular with many Pakeha, much Maori behaviour was mocked, including by children. Many Maori were seen as being unsophisticated, unable to express themselves properly in English, and prone to drunkenness and laziness, whereas those who adopted Pakeha ways were praised.
Some Pakeha sympathized with poverty-stricken Maori and regretted the decline of their language. There were many examples of close and friendly relations and of Maori assisting Pakeha in trouble, but in general they lived geographically separate lives. To earn money, Maori were forced to work at road making, timber cutting, gum digging, and farming what land remained in their possession. Most Maori struggled financially, their limited resources being stretched by holding expensive tangi and entertaining visitors – resulting in more land sales. They used the court system to defend their economic interests.
Ngati Rahiri (including supporters of the Kingitanga) were seen as ‘loyal’ to the Crown, and visiting Maori kings received kindly treatment from Pakeha as well as from Maori. 
Poor health prompted some government assistance, but poor housing remained, although some attempts were made to improve it (partly to protect Pakeha from diseases). Before the twentieth century only a few children, mostly ‘half-castes’, were educated. Most Ngati Rahiri were members of the Church of England before being attracted by the new Mormon faith.
Ngati Rahiri participated with Pakeha in horse races, sporting contests, and, especially, rugby, and a few joined the Volunteers. Much less desirable to most residents was their heavy drinking (encouraged by some publicans and their Pakeha drinking buddies), and occasional fights, very occasionally with Pakeha. Overall, Pakeha ways, both good and bad, of necessity were adopted, and Ngati Rahiri became inextricably a subordinate part of the Pakeha community, although still retaining some distinctive features. 

 (Note: Unless otherwise indicated, all those named in this paper, both Maori and Pakeha, were shareholders in claims in the Te Aroha district.)

year: 2016