title: The development of a novel large area building integrated solar collector for pool heating

authors: Anderson, Timothy Nicholas

subjects: building integrated solar collector

abstract: Unglazed solar collectors have often been used a means of providing low cost heating to swimming pools. However, these systems are typically polymer style “mats” that are laid on top of a roof, often leading to poor aesthetics due to their lack of integration with the building itself. This study charts the development of a novel large area unglazed building integrated solar pool heating system (BIT), based on long run sheet metal roofing, from its initial conceptualisation through to its implementation. It discusses the design of the building integrated solar collector modules, the assessment of their performance through theoretical modelling and experimental validation. Subsequently, it shows the scaling of laboratory scale testing to a large area array through modelling and discusses the performance of the system in the “as-built” configuration. In doing this, it provides a succinct illustration of the design process for the development of the University of Waikato’s building integrated pool heating system.

text: The development of a novel large area building integrated solar collector for pool heating Unglazed solar collectors have often been used a means of providing low cost heating to swimming pools. However, these systems are typically polymer style “mats” that are laid on top of a roof, often leading to poor aesthetics due to their lack of integration with the building itself. This study charts the development of a novel large area unglazed building integrated solar pool heating system (BIT), based on long run sheet metal roofing, from its initial conceptualisation through to its implementation. It discusses the design of the building integrated solar collector modules, the assessment of their performance through theoretical modelling and experimental validation. Subsequently, it shows the scaling of laboratory scale testing to a large area array through modelling and discusses the performance of the system in the “as-built” configuration. In doing this, it provides a succinct illustration of the design process for the development of the University of Waikato’s building integrated pool heating system.

year: 2010

title: Changes in natural ¹⁵n abundance in pastoral soils receiving differing amounts of superphosphate fertilizer and irrigation for 50 years

authors: Mudge, Paul Lawrence

abstract: Intensification of pastoral agriculture has led to increased N losses to the wider environment. This has led to an emphasis on improving our understanding of soil N dynamics, and development of management practices which mitigate N losses. The natural abundance of the stable isotope δ¹⁵N relative to ¹⁴N (δ¹⁵N) in soils can provide an integrated measure of past N cycle processes, and in particular soil δ15N can reflect past N losses, because during most N transformation processes 14N is preferentially lost. We therefore hypothesized that pastoral soils under intensive management regimes (with high N inputs, cycling, and loss) would become progressively enriched with ¹⁵N relative to soils under less intensive management. To test this hypothesis we analyzed archived surface soils from two long-term grazed field trials in New Zealand, where different rates of irrigation and superphosphate fertilizer had been applied for ∼50 yr. In all treatments except one (a control treatment receiving no fertilizer), δ¹⁵N increased with time and the increase was greater in treatments receiving more superphosphate or irrigation (average increases ranged from ∼0.015–0.034 ‰ yr–1). Pasture production and grazing intensity also increased with increasing fertilizer rate and irrigation frequency, and we found positive correlations between the average rate of change in soil δ¹⁵N, and total pasture production (r² = 0.77, p = 0.02), clover production (r² = 0.95, p < 0.001), and calculated N losses (r² = 0.98, p < 0.001) over ∼50 yr. We suggest that most of the difference in δ¹⁵N observed between treatments was due to the influence fertilizer and irrigation had on pasture production, and the resulting effects this had on isotope fractionating N loss processes. Soil δ¹⁵N could therefore be a useful indicator of past management intensity and N cycling and loss from pastoral systems.

text: Changes in natural ¹⁵n abundance in pastoral soils receiving differing amounts of superphosphate fertilizer and irrigation for 50 years Intensification of pastoral agriculture has led to increased N losses to the wider environment. This has led to an emphasis on improving our understanding of soil N dynamics, and development of management practices which mitigate N losses. The natural abundance of the stable isotope δ¹⁵N relative to ¹⁴N (δ¹⁵N) in soils can provide an integrated measure of past N cycle processes, and in particular soil δ15N can reflect past N losses, because during most N transformation processes 14N is preferentially lost. We therefore hypothesized that pastoral soils under intensive management regimes (with high N inputs, cycling, and loss) would become progressively enriched with ¹⁵N relative to soils under less intensive management. To test this hypothesis we analyzed archived surface soils from two long-term grazed field trials in New Zealand, where different rates of irrigation and superphosphate fertilizer had been applied for ∼50 yr. In all treatments except one (a control treatment receiving no fertilizer), δ¹⁵N increased with time and the increase was greater in treatments receiving more superphosphate or irrigation (average increases ranged from ∼0.015–0.034 ‰ yr–1). Pasture production and grazing intensity also increased with increasing fertilizer rate and irrigation frequency, and we found positive correlations between the average rate of change in soil δ¹⁵N, and total pasture production (r² = 0.77, p = 0.02), clover production (r² = 0.95, p < 0.001), and calculated N losses (r² = 0.98, p < 0.001) over ∼50 yr. We suggest that most of the difference in δ¹⁵N observed between treatments was due to the influence fertilizer and irrigation had on pasture production, and the resulting effects this had on isotope fractionating N loss processes. Soil δ¹⁵N could therefore be a useful indicator of past management intensity and N cycling and loss from pastoral systems.

year: 2013

title: Kua Huri Taku Tira: The Rereahu Journey Towards Autonomy

authors: Crown, Jenny

subjects: autonomy

abstract: The establishment of the Native Land Court in Aotearoa New Zealand by the settler government caused much upheaval for tangata whenua. Traditional land tenure was interrupted by the colonised view of land ownership. Impetus to establish individual ownership of land was placed upon iwi and hapū Māori. This necessitated the iwi and hapū of the Rohe Pōtae to define their own individual boundaries within the autonomous region.

Over one hundred years later, the New Zealand government were under pressure from the Māori community. Iwi and hapū were vociferous in their requirements. The returning of land and natural resources to Māori was of paramount importance. The implementation of the Māori Trust Board Act enabled iwi and hapū to establish governance entities which permitted access to government funding. These entities also provided a vehicle through which iwi could pursue cultural redress from the Crown. This was the only way forward – the way dictated by the Crown.

Devolution was to become a reality and a sign of the decolonisation process at play. Such would allow Māori to re-establish autonomy which had been lost over a century prior. Destructive notions such as marginalisation, disenfranchisement and displacement would be reversed and Māori would regain control over their own cultural practices, cultural resources and future. Under the Fourth Labour Government of New Zealand this became a reality for some iwi and hapū.

This thesis investigates the attempts made by the Rereahu iwi in securing such recognition. Interrogation into the many ways in which Rereahu has attempted to navigate the multiple political landscapes which still exist and continue to control iwi and hapū have been discussed. The study develops a theoretical framework of Māori wide concepts as applied through a Rereahu-centric lens. Thus, allowing for a balanced approach to the collection, collation and analysis of all evidence utilised in this thesis.

Key findings bring to light the effects colonisation has had and continues to have on Rereahu autonomy. The ways in which Rereahu has been misrepresented, and how Rereahu has responded to threats of colonisation in the 21st century are apparent. This thesis contributes new knowledge to the realm of academia through the experiences of the iwi Rereahu; and offers indigenous discourse regarding resilience and resistance.

The ongoing effects of colonisation being felt by the Rereahu iwi in this contemporary landscape are defined. It is an example of how the oppressed can easily become the oppressor. This thesis goes some way to highlighting the destructive nature of the Waitangi Tribunal process in regards to Rereahu. The knowledge presented in this thesis could be utilised by the Office of Treaty Settlements, education and health establishments, policy makers and the iwi of Rereahu in addressing and combating the negative effects created by the cycle of colonisation.

text: Kua Huri Taku Tira: The Rereahu Journey Towards Autonomy The establishment of the Native Land Court in Aotearoa New Zealand by the settler government caused much upheaval for tangata whenua. Traditional land tenure was interrupted by the colonised view of land ownership. Impetus to establish individual ownership of land was placed upon iwi and hapū Māori. This necessitated the iwi and hapū of the Rohe Pōtae to define their own individual boundaries within the autonomous region.

Over one hundred years later, the New Zealand government were under pressure from the Māori community. Iwi and hapū were vociferous in their requirements. The returning of land and natural resources to Māori was of paramount importance. The implementation of the Māori Trust Board Act enabled iwi and hapū to establish governance entities which permitted access to government funding. These entities also provided a vehicle through which iwi could pursue cultural redress from the Crown. This was the only way forward – the way dictated by the Crown.

Devolution was to become a reality and a sign of the decolonisation process at play. Such would allow Māori to re-establish autonomy which had been lost over a century prior. Destructive notions such as marginalisation, disenfranchisement and displacement would be reversed and Māori would regain control over their own cultural practices, cultural resources and future. Under the Fourth Labour Government of New Zealand this became a reality for some iwi and hapū.

This thesis investigates the attempts made by the Rereahu iwi in securing such recognition. Interrogation into the many ways in which Rereahu has attempted to navigate the multiple political landscapes which still exist and continue to control iwi and hapū have been discussed. The study develops a theoretical framework of Māori wide concepts as applied through a Rereahu-centric lens. Thus, allowing for a balanced approach to the collection, collation and analysis of all evidence utilised in this thesis.

Key findings bring to light the effects colonisation has had and continues to have on Rereahu autonomy. The ways in which Rereahu has been misrepresented, and how Rereahu has responded to threats of colonisation in the 21st century are apparent. This thesis contributes new knowledge to the realm of academia through the experiences of the iwi Rereahu; and offers indigenous discourse regarding resilience and resistance.

The ongoing effects of colonisation being felt by the Rereahu iwi in this contemporary landscape are defined. It is an example of how the oppressed can easily become the oppressor. This thesis goes some way to highlighting the destructive nature of the Waitangi Tribunal process in regards to Rereahu. The knowledge presented in this thesis could be utilised by the Office of Treaty Settlements, education and health establishments, policy makers and the iwi of Rereahu in addressing and combating the negative effects created by the cycle of colonisation.

year: 2019