title: An ecological perspective on ‘undisturbed’ lake catchments in the Rotorua District

authors: Shaw, William

abstract: There is currently concern about trends in water quality in some lakes in largely natural catchments. Various potential contributing causes are under consideration, including pest animals, such as wallabies, and pest plants. This presentation provides an overview of aspects of ecological history and processes at work in the catchments of selected lakes. By necessity, this is largely an historical analysis, but this provides important background for current trends, and also to understand landscape-level processes. The effects of potentially threatening influences, such as pest plants and animals, need to be evaluated within various contexts, including landscape history, ongoing geomorphological change, human disturbance, vegetation dynamics, and the relative contributions of natural and human-induced changes.

text: An ecological perspective on ‘undisturbed’ lake catchments in the Rotorua District There is currently concern about trends in water quality in some lakes in largely natural catchments. Various potential contributing causes are under consideration, including pest animals, such as wallabies, and pest plants. This presentation provides an overview of aspects of ecological history and processes at work in the catchments of selected lakes. By necessity, this is largely an historical analysis, but this provides important background for current trends, and also to understand landscape-level processes. The effects of potentially threatening influences, such as pest plants and animals, need to be evaluated within various contexts, including landscape history, ongoing geomorphological change, human disturbance, vegetation dynamics, and the relative contributions of natural and human-induced changes.

year: 2015

title: Rheology of the gel formed in the California Mastitis Test

authors: Verbeek, Casparus Johan R.

subjects: Capillary viscosity

abstract: The California Mastitis Test has previously been adapted for use in an inline, cow-side sensor and relies on the fact that the viscosity of the gel formed during the test is proportional to the somatic cell concentration. In this paper, the use of capillary and rotational viscometry was compared in light of the expected rheology of the gel formed during the test. It was found that the gel is non-Newtonian, but the initial phase of viscosity increase was not due to shear dependence, but rather due to the gelation reaction. The maximum apparent viscosity of the gel was shear dependent while the time it took to reach the maximum was not truly shear dependent, but was rather dependent on the degree of mixing during gelation. This was confirmed by introducing a delay time prior to viscosity measurement, in both capillary and rotational viscometry. It was found that by mixing the reagent and infected milk, then delaying viscosity measurement for 30 s, shortened the time it took to reach maximum viscosity by more than 60 s. The maximum apparent viscosity, however, was unaffected. It was found that capillary viscometry worked well to correlate relative viscosity with somatic cell count, but that it was sensitive to the reagent concentration. It can therefore be deduced that the rheology of the gel is complicated not only by it being non-Newtonian, but also by the strong dependence on test conditions. These make designing a successful sensor much more challenging.

text: Rheology of the gel formed in the California Mastitis Test The California Mastitis Test has previously been adapted for use in an inline, cow-side sensor and relies on the fact that the viscosity of the gel formed during the test is proportional to the somatic cell concentration. In this paper, the use of capillary and rotational viscometry was compared in light of the expected rheology of the gel formed during the test. It was found that the gel is non-Newtonian, but the initial phase of viscosity increase was not due to shear dependence, but rather due to the gelation reaction. The maximum apparent viscosity of the gel was shear dependent while the time it took to reach the maximum was not truly shear dependent, but was rather dependent on the degree of mixing during gelation. This was confirmed by introducing a delay time prior to viscosity measurement, in both capillary and rotational viscometry. It was found that by mixing the reagent and infected milk, then delaying viscosity measurement for 30 s, shortened the time it took to reach maximum viscosity by more than 60 s. The maximum apparent viscosity, however, was unaffected. It was found that capillary viscometry worked well to correlate relative viscosity with somatic cell count, but that it was sensitive to the reagent concentration. It can therefore be deduced that the rheology of the gel is complicated not only by it being non-Newtonian, but also by the strong dependence on test conditions. These make designing a successful sensor much more challenging.

year: 2008

title: Indigenous-washing and colonial amnesia: how New Zealand’s nation brand depoliticizes climate change

authors: Hellmann, Olli

abstract: New Zealand’s nation brand has drawn ever louder accusations of “greenwashing” the country’s image in recent years. Through a visual discourse analysis of Air New Zealand’s Tiaki & The Guardians safety briefing video, this article shows that brand managers have responded with a strategy of “Indigenous-washing,” appropriating the Māori worldview to deflect attention from intensive farming’s carbon footprint and other environmentally unfriendly activities. More broadly, this article makes an important contribution to the growing critical-cultural literature on nation branding by revealing how New Zealand’s latest marketing initiative contributes to the depoliticization of climate change. The “Tiaki” campaign not only positions New Zealand as an “untouched land,” but also closes the space for democratic debate about climate change by obscuring the role of colonialism in causing the planet’s ecological crisis and by silencing alternative socioecological futures proposed by Indigenous peoples.

text: Indigenous-washing and colonial amnesia: how New Zealand’s nation brand depoliticizes climate change New Zealand’s nation brand has drawn ever louder accusations of “greenwashing” the country’s image in recent years. Through a visual discourse analysis of Air New Zealand’s Tiaki & The Guardians safety briefing video, this article shows that brand managers have responded with a strategy of “Indigenous-washing,” appropriating the Māori worldview to deflect attention from intensive farming’s carbon footprint and other environmentally unfriendly activities. More broadly, this article makes an important contribution to the growing critical-cultural literature on nation branding by revealing how New Zealand’s latest marketing initiative contributes to the depoliticization of climate change. The “Tiaki” campaign not only positions New Zealand as an “untouched land,” but also closes the space for democratic debate about climate change by obscuring the role of colonialism in causing the planet’s ecological crisis and by silencing alternative socioecological futures proposed by Indigenous peoples.

year: 2023-07-27