title: The Value of Irrigation Water in New Zealand

authors: Kravchenko, Alexey

subjects: irrigation

abstract: The aim of this thesis is to examine issues pertaining to freshwater quantity in New Zealand agriculture. Currently, freshwater is managed under the Resource Management Act (1991) and the allocation system is essentially on a “first-come first-served” basis – whoever gains access to water rights first blocks out subsequent users, if catchment allocation limits have been reached.   One of the recommendations from a government taskforce engaged to look at the issues of freshwater management suggests that market mechanisms or charges could be viable options of demand management. For any such market or price mechanism to work, it is imperative to know the value of irrigation water in New Zealand as well as to understand wider economic ramifications of establishing such mechanisms. Currently, there is relatively little research concerning these issues and this thesis aims to fill this research gap. The methodologies used include an econometric analysis of dairy farm panel data, a stated choice experiment of irrigation consent holders and a computable general equilibrium [CGE] analysis. In addition to filling the research gap, this thesis also aims to provide improvements in each of the methodologies used. Panel data analysis imputes the water demand function without actual data on water through examining the relationship between milksolid production and output-weighted expected payout – a unique dairy price index developed that more accurately reflects farmers’ incentives than the final payout. The choice modelling section pays particular attention to the issue of attribute non-attendance [ANA], eexamining  its effects on model outputs and compares methods of data collection on ANA. The main findings of the survey suggest that the majority of farmers would be willing to pay for water instead of facing an abstraction ban. In terms of ANA, the results indicate that not accounting for ANA, particularly if it is due to heuristics or respondent fatigue, may significantly bias the welfare estimates and decrease statistical significance. A novel calibration method is presented to negate the ANA bias. Finally, the CGE modelling work modifies the well-known GTAP model to include water as factor of production, as well as to disaggregate the results to a regional level within the New Zealand economy. The findings indicate strong interconnectedness between sectors and regions, with policies in one region having the potential to affect economic activity and resource demand in other regions.

text: The Value of Irrigation Water in New Zealand The aim of this thesis is to examine issues pertaining to freshwater quantity in New Zealand agriculture. Currently, freshwater is managed under the Resource Management Act (1991) and the allocation system is essentially on a “first-come first-served” basis – whoever gains access to water rights first blocks out subsequent users, if catchment allocation limits have been reached.   One of the recommendations from a government taskforce engaged to look at the issues of freshwater management suggests that market mechanisms or charges could be viable options of demand management. For any such market or price mechanism to work, it is imperative to know the value of irrigation water in New Zealand as well as to understand wider economic ramifications of establishing such mechanisms. Currently, there is relatively little research concerning these issues and this thesis aims to fill this research gap. The methodologies used include an econometric analysis of dairy farm panel data, a stated choice experiment of irrigation consent holders and a computable general equilibrium [CGE] analysis. In addition to filling the research gap, this thesis also aims to provide improvements in each of the methodologies used. Panel data analysis imputes the water demand function without actual data on water through examining the relationship between milksolid production and output-weighted expected payout – a unique dairy price index developed that more accurately reflects farmers’ incentives than the final payout. The choice modelling section pays particular attention to the issue of attribute non-attendance [ANA], eexamining  its effects on model outputs and compares methods of data collection on ANA. The main findings of the survey suggest that the majority of farmers would be willing to pay for water instead of facing an abstraction ban. In terms of ANA, the results indicate that not accounting for ANA, particularly if it is due to heuristics or respondent fatigue, may significantly bias the welfare estimates and decrease statistical significance. A novel calibration method is presented to negate the ANA bias. Finally, the CGE modelling work modifies the well-known GTAP model to include water as factor of production, as well as to disaggregate the results to a regional level within the New Zealand economy. The findings indicate strong interconnectedness between sectors and regions, with policies in one region having the potential to affect economic activity and resource demand in other regions.

year: 2016

title: Aspects of the chemistry of milk protein films formed on stainless steel

authors: Nisbet, Trevor John

abstract: The literature on the properties of stainless steel surfaces, the physico-chemical properties of milk and the surface chemistry of proteins was reviewed to gain an insight into the formation, of protein-mineral films (“milkstone”) on the contact surfaces of dairy milk lines. Protein adsorption processes were considered fundamental to the formation of such deposits. Standard methods of protein separation and purification were employed to obtain purified αₛ₁, β, and K-casein. 
Radiochemical methods provided a convenient means of studying protein adsorption on to low surface area systems. Of the various methods for labelling proteins, radioiodination by a slightly modified version of Hunter and Greenwood Chloramine T method proved to be the most satisfactory. By this method, stable labelled milk proteins of high specific activity containing not more than one iodine atom per protein molecule and having properties that could not be distinguished from those of unlabelled proteins were prepared.
In the course of the work several further aspects of the iodination reaction and the reactions of iodine species with milk components were investigated. Iodination efficiencies were found to be sensitive to the storage time of the radioactive iodine stock solutions (supplied free of reducing agent at pH 8-11). The drop in iodination efficiency was correlated with an increase in the concentration of oxidised iodine species in the radioactive stock solutions. Studies of the iodination of whole milk showed that with the exception of K-casein, the tyrosyl residues of all proteins in milk were iodinated with approximately the same iodination efficiency. The iodination efficiencies of K-casein tyrosyls were significantly lower. A theoretical examination of the effect of the hydrophobicity of the molecular environment on tyrosyl iodination efficiency, indicated the likelihood that the affect observed was due to the incorporation of the K-casein in inaccessible regions of the micelle rather than a molecular environment effect.
Iodinated caseins, when added to whole skim milk became bound to the micelle fraction. In the case of β and K-casein, the binding was temperature dependent and at least partially reversible. αₛ₁-casein binding to micelle was largely independent of temperature and irreversible. The stabilising effect of calcium ions on diluted micelle suspensions was demonstrated. The variation in the K-casein content of casein micelles with micelle size was also demonstrated. When inorganic iodine was added to milk, part of this became encapsulated by milk micelles. However, there was virtually no chemical binding of the iodine to the milk proteins of cooled milk. 
Techniques were developed to study the surface chemistry of radioactively labelled milk proteins at stainless steel-water interfaces. The amount adsorbed was calculated according to the principle of isotope dilution. Autoradiography and high resolution autoradiography, using nuclear track emulsion and scanning electron microscopy confirmed the uniform distribution of the adsorbed protein. Studies of adsorption from whole skim milk, whey and milk serum, indicated that of the various milk proteins serum caseins had the greatest affinity for stainless steel surfaces. Adsorption data for purified caseins and mixtures of casein indicated that β-casein was the species preferentially adsorbed. Generally it was observed that adsorption was largely irreversible and providing adequate time was allowed, proceeded to form a relatively constant close packed film of adsorbed protein molecules. The amount of protein in the films ranged from 2.0 mg m⁻² to 3.0 mg m⁻² irrespective of protein concentration, except at high concentrations of β-casein and to some extent, αₛ₁-casein, where a second adsorption process seemed to be present. This effect also seemed to be present in studies of adsorption from whole milk. 
The kinetics of adsorption and desorption were monitored by tracer techniques. The data for adsorption from unstirred solutions indicated the process was diffusion controlled. A diffusion model was developed which accounted for the rate of adsorption and the amount adsorbed in terms of the size, shape and hydration of the protein molecule, the viscosity of the medium and the effective surface area of the stainless steel surface. The model was used to estimate hydration and axial ratio values for β-casein. Values of 1.9 grams of water per gram of protein for the  hydration, and 11 for the axial ratio (a/b) were obtained. 
Desorption of adsorbed protein is a complex process that does not obey simple rate laws. Desorption was facilitated by hydroxyl ions and anionic surfactants but no simple relationship between rate of desorption and species concentration was obtained.
Simple adsorption process cannot account for the formation of macroscopic milk protein films on milk contact surfaces. After the surface has been covered by the initial adsorbed layer, no further protein could be adsorbed until the surface of this layer was modified in some way, for example, by the adsorption of positively charged colloids of iron oxide, chromium oxide or calcium phosphate. Deposition by evaporation of solution films, or precipitation from solution are other mechanisms by which macroscopic films may be formed. The film thicknesses of the drained milk films formed after immersions of clean stainless steel surfaces into dilute milk solutions remained independent of dilution at 3.8 ± 0.6 x 10⁻⁴ cm. The properties of protein films formed at surfaces can be altered by thermal denaturation, chemical modification and also presumably by bacterial action. 
Analytical and microscopic examination of actual milkstone deposits generally supported a previous milkstone classification based upon chemical analysis, i.e. fat deposits, high protein, deposits, calcium phosphate milkstone and iron milkstone. As a result of the present investigation the further classification of high protein deposits into chlorine-induced (from sodium hypochlorite) and phosphate-induced (from phosphoric acid) was suggested. It does not seem likely that milkstone deposits are formed by a single mechanism. This conclusion was supported by an analysis of data for deposits formed in simulator trials where evaporation of milk films (in one simulator) and precipitation induced by hypochlorite (in two simulators) were major factors. The variety of possible mechanisms for deposition is due to the range of conditions that can occur in milk lines. The results of the present work will assist in determining the mechanism operative in a particular case and will allow the development of better procedures for the removal and prevention of such deposits.

text: Aspects of the chemistry of milk protein films formed on stainless steel The literature on the properties of stainless steel surfaces, the physico-chemical properties of milk and the surface chemistry of proteins was reviewed to gain an insight into the formation, of protein-mineral films (“milkstone”) on the contact surfaces of dairy milk lines. Protein adsorption processes were considered fundamental to the formation of such deposits. Standard methods of protein separation and purification were employed to obtain purified αₛ₁, β, and K-casein. 
Radiochemical methods provided a convenient means of studying protein adsorption on to low surface area systems. Of the various methods for labelling proteins, radioiodination by a slightly modified version of Hunter and Greenwood Chloramine T method proved to be the most satisfactory. By this method, stable labelled milk proteins of high specific activity containing not more than one iodine atom per protein molecule and having properties that could not be distinguished from those of unlabelled proteins were prepared.
In the course of the work several further aspects of the iodination reaction and the reactions of iodine species with milk components were investigated. Iodination efficiencies were found to be sensitive to the storage time of the radioactive iodine stock solutions (supplied free of reducing agent at pH 8-11). The drop in iodination efficiency was correlated with an increase in the concentration of oxidised iodine species in the radioactive stock solutions. Studies of the iodination of whole milk showed that with the exception of K-casein, the tyrosyl residues of all proteins in milk were iodinated with approximately the same iodination efficiency. The iodination efficiencies of K-casein tyrosyls were significantly lower. A theoretical examination of the effect of the hydrophobicity of the molecular environment on tyrosyl iodination efficiency, indicated the likelihood that the affect observed was due to the incorporation of the K-casein in inaccessible regions of the micelle rather than a molecular environment effect.
Iodinated caseins, when added to whole skim milk became bound to the micelle fraction. In the case of β and K-casein, the binding was temperature dependent and at least partially reversible. αₛ₁-casein binding to micelle was largely independent of temperature and irreversible. The stabilising effect of calcium ions on diluted micelle suspensions was demonstrated. The variation in the K-casein content of casein micelles with micelle size was also demonstrated. When inorganic iodine was added to milk, part of this became encapsulated by milk micelles. However, there was virtually no chemical binding of the iodine to the milk proteins of cooled milk. 
Techniques were developed to study the surface chemistry of radioactively labelled milk proteins at stainless steel-water interfaces. The amount adsorbed was calculated according to the principle of isotope dilution. Autoradiography and high resolution autoradiography, using nuclear track emulsion and scanning electron microscopy confirmed the uniform distribution of the adsorbed protein. Studies of adsorption from whole skim milk, whey and milk serum, indicated that of the various milk proteins serum caseins had the greatest affinity for stainless steel surfaces. Adsorption data for purified caseins and mixtures of casein indicated that β-casein was the species preferentially adsorbed. Generally it was observed that adsorption was largely irreversible and providing adequate time was allowed, proceeded to form a relatively constant close packed film of adsorbed protein molecules. The amount of protein in the films ranged from 2.0 mg m⁻² to 3.0 mg m⁻² irrespective of protein concentration, except at high concentrations of β-casein and to some extent, αₛ₁-casein, where a second adsorption process seemed to be present. This effect also seemed to be present in studies of adsorption from whole milk. 
The kinetics of adsorption and desorption were monitored by tracer techniques. The data for adsorption from unstirred solutions indicated the process was diffusion controlled. A diffusion model was developed which accounted for the rate of adsorption and the amount adsorbed in terms of the size, shape and hydration of the protein molecule, the viscosity of the medium and the effective surface area of the stainless steel surface. The model was used to estimate hydration and axial ratio values for β-casein. Values of 1.9 grams of water per gram of protein for the  hydration, and 11 for the axial ratio (a/b) were obtained. 
Desorption of adsorbed protein is a complex process that does not obey simple rate laws. Desorption was facilitated by hydroxyl ions and anionic surfactants but no simple relationship between rate of desorption and species concentration was obtained.
Simple adsorption process cannot account for the formation of macroscopic milk protein films on milk contact surfaces. After the surface has been covered by the initial adsorbed layer, no further protein could be adsorbed until the surface of this layer was modified in some way, for example, by the adsorption of positively charged colloids of iron oxide, chromium oxide or calcium phosphate. Deposition by evaporation of solution films, or precipitation from solution are other mechanisms by which macroscopic films may be formed. The film thicknesses of the drained milk films formed after immersions of clean stainless steel surfaces into dilute milk solutions remained independent of dilution at 3.8 ± 0.6 x 10⁻⁴ cm. The properties of protein films formed at surfaces can be altered by thermal denaturation, chemical modification and also presumably by bacterial action. 
Analytical and microscopic examination of actual milkstone deposits generally supported a previous milkstone classification based upon chemical analysis, i.e. fat deposits, high protein, deposits, calcium phosphate milkstone and iron milkstone. As a result of the present investigation the further classification of high protein deposits into chlorine-induced (from sodium hypochlorite) and phosphate-induced (from phosphoric acid) was suggested. It does not seem likely that milkstone deposits are formed by a single mechanism. This conclusion was supported by an analysis of data for deposits formed in simulator trials where evaporation of milk films (in one simulator) and precipitation induced by hypochlorite (in two simulators) were major factors. The variety of possible mechanisms for deposition is due to the range of conditions that can occur in milk lines. The results of the present work will assist in determining the mechanism operative in a particular case and will allow the development of better procedures for the removal and prevention of such deposits.

year: 1979

title: Colonial versus ancestral legacy: The assertion of culture and identity through public arts in Kirikiriroa/Hamilton

authors: Kiff, Shirin

subjects: Ethnography

abstract: This thesis is an ethnography of Hamilton. It focuses on the role of public arts as a cultural regeneration tool and their function in shaping the community(s) in Kirikiriroa/Hamilton through building a sense of place and identity. As a qualitative study, I conducted nine semi- structured interviews with public art artists, art advocates and residents to explore the relational context within which the development and transmission of meaning takes place, a process which is central to culture and identity. The primary purpose of the research interviews was to gain insight into the factors that motivate arts organisers and planners to direct valuable limited resources into public art projects and its observable outcomes. The second purpose of the interviews, conducted while walking to public artworks in the city centre with six participants, was to examine the effect of public art on the public.
My methods also include tracking press reviews, monitoring comments and posts on social media and institutional debates involving residents, artists, and public authorities concerning public arts. I also recorded data by taking photographs and recording field notes of my observations during and after the fieldwork process. Data gathering was also enhanced by the large-scale collection of written materials and resources, including public art publications and HCC policy documents. Taken together, these research methods allowed me to investigate whether Hamilton had achieved its goals in its cultural regeneration efforts. In my analysis, I discuss the role of public art and its association with place and consider how artworks may antagonise Māori-Pākehā relationships or otherwise emphasis residents’ sense of place.
Biculturalism and monoculturalism narratives appear to dominate public arts with the purpose of invoking either a colonial legacy or ancestral legacy while the politics of multiculturalism continue to jockey for place. Colonial legacy refers to the glorifying of colonial achievements while ancestral legacy in this context refers to Māori assertion of history, culture and identity. Particularly, in this research, ancestral legacy belonging to local hapū, Ngāti Wairere. Participants’ narratives reveal four overarching themes, 1) the publics’ resistance to the making of colonial places through public art, 2) Ngāti Wairere struggles to assert ancestral legacy through public arts, 3) the need for ethnically diverse artworks to create and maintain ethnically diverse places, and 4) a yearning for a collective identity represented through public arts. Hamilton’s public artworks are variously perceived as a superficial representation of Māori culture, identity and history, a reminder of a colonial binary discourse, the colonised versus the coloniser, an assertion of either a Māori ancestral legacy or a colonial legacy or, minimally, a nod to multiculturalism. Nevertheless, my research shows that participants engagement with these artworks reveal a yearning for a local collective identity that is still a work in progress.

text: Colonial versus ancestral legacy: The assertion of culture and identity through public arts in Kirikiriroa/Hamilton This thesis is an ethnography of Hamilton. It focuses on the role of public arts as a cultural regeneration tool and their function in shaping the community(s) in Kirikiriroa/Hamilton through building a sense of place and identity. As a qualitative study, I conducted nine semi- structured interviews with public art artists, art advocates and residents to explore the relational context within which the development and transmission of meaning takes place, a process which is central to culture and identity. The primary purpose of the research interviews was to gain insight into the factors that motivate arts organisers and planners to direct valuable limited resources into public art projects and its observable outcomes. The second purpose of the interviews, conducted while walking to public artworks in the city centre with six participants, was to examine the effect of public art on the public.
My methods also include tracking press reviews, monitoring comments and posts on social media and institutional debates involving residents, artists, and public authorities concerning public arts. I also recorded data by taking photographs and recording field notes of my observations during and after the fieldwork process. Data gathering was also enhanced by the large-scale collection of written materials and resources, including public art publications and HCC policy documents. Taken together, these research methods allowed me to investigate whether Hamilton had achieved its goals in its cultural regeneration efforts. In my analysis, I discuss the role of public art and its association with place and consider how artworks may antagonise Māori-Pākehā relationships or otherwise emphasis residents’ sense of place.
Biculturalism and monoculturalism narratives appear to dominate public arts with the purpose of invoking either a colonial legacy or ancestral legacy while the politics of multiculturalism continue to jockey for place. Colonial legacy refers to the glorifying of colonial achievements while ancestral legacy in this context refers to Māori assertion of history, culture and identity. Particularly, in this research, ancestral legacy belonging to local hapū, Ngāti Wairere. Participants’ narratives reveal four overarching themes, 1) the publics’ resistance to the making of colonial places through public art, 2) Ngāti Wairere struggles to assert ancestral legacy through public arts, 3) the need for ethnically diverse artworks to create and maintain ethnically diverse places, and 4) a yearning for a collective identity represented through public arts. Hamilton’s public artworks are variously perceived as a superficial representation of Māori culture, identity and history, a reminder of a colonial binary discourse, the colonised versus the coloniser, an assertion of either a Māori ancestral legacy or a colonial legacy or, minimally, a nod to multiculturalism. Nevertheless, my research shows that participants engagement with these artworks reveal a yearning for a local collective identity that is still a work in progress.

year: 2021