title: Slowest to fastest: Extreme range in lichen growth rates supports their use as an indicator of climate change in Antarctica

authors: Sancho, Leopoldo G.

subjects: lichenometry

abstract: Global temperature rise is suggested to be greater and more rapid in polar regions. There has been a clear temperature rise of 0.056 °C y⁻¹ in the Antarctic Peninsula and this has led to changes in higher plant extent and range. In the more extreme environments of the main continent the vegetation is scattered and composed of lichens and mosses. There is interest in the possible effects of global climatechange on these communities acting through changes in temperature and precipitation. Lichens have been extensively used to date the substrates on which they are growing using the techniques of lichenometry. The slowgrowth and longevity of lichens particularly suites them for this use. We present evidence that there appears to be a substantial (two orders of magnitude) cline in lichengrowthrate from the warmer, wetter and more productive Peninsula to the cold Dry Valleys at 77°S latitude. The differences in growthrate reflect the precipitation and temperature regimes at the different sites. The large range in growthrates coupled with the simplicity of measuring lichengrowth using modern techniques suggests that this could be an excellent tool for the detection of climatechange in continental Antarctica.

text: Slowest to fastest: Extreme range in lichen growth rates supports their use as an indicator of climate change in Antarctica Global temperature rise is suggested to be greater and more rapid in polar regions. There has been a clear temperature rise of 0.056 °C y⁻¹ in the Antarctic Peninsula and this has led to changes in higher plant extent and range. In the more extreme environments of the main continent the vegetation is scattered and composed of lichens and mosses. There is interest in the possible effects of global climatechange on these communities acting through changes in temperature and precipitation. Lichens have been extensively used to date the substrates on which they are growing using the techniques of lichenometry. The slowgrowth and longevity of lichens particularly suites them for this use. We present evidence that there appears to be a substantial (two orders of magnitude) cline in lichengrowthrate from the warmer, wetter and more productive Peninsula to the cold Dry Valleys at 77°S latitude. The differences in growthrate reflect the precipitation and temperature regimes at the different sites. The large range in growthrates coupled with the simplicity of measuring lichengrowth using modern techniques suggests that this could be an excellent tool for the detection of climatechange in continental Antarctica.

year: 2007

title: Distinguishability of rechargeable battery equivalent circuit models

authors: Poihipi, Eden Kathleen

subjects: ECM

abstract: The contention made by Berthier et al. - that competing fractional-element equivalent- circuit models of battery cells are indistinguishable in the presence of noise - is revisited in this work. A set of six equivalent circuit models (ECMs) were chosen as a subset of West- erhoff’s generalised ECM from 2016. These six ECMs had increasing complexity, and gave a simulated output similar to that of an idealised Lithium battery impedance spec- trum. By extending the frequency range of Berthier, using methods suggested by both Mauracher & Karden, and Hasan & Scott, sets of simulated electrochemical impedance spectra (EIS) are generated. A Nelder-Mead based optimisation method, which em- ploys multiple restarts, is used to fit each ECM to the sets simulated data. The data was produced with 0%, 1%, 3% and 5% noise. The optimisations showed that all six ECMs were distinguishable at 0% noise, but as the noise increased - distinguishability is lost. Typically a 4-element ECM is shown to model the simulated data with preci- sion which is comparable to the error in the data. When optimising the ECMs against measured data (measured with an Egilent 66332A, E5270 and a Keithley 2460A) from INR and NCA batteries, it is seen that the 3-element ECMs are an adequate model. However there is some variation between the two battery chemistries. Battery ageing and the measurement system used also contribute to variation in which ECM models the data best. Further work on this project should include repeating this fitting method on different battery chemistries, and collating and fitting ECMs to a battery which is measured at different points as it ages.

text: Distinguishability of rechargeable battery equivalent circuit models The contention made by Berthier et al. - that competing fractional-element equivalent- circuit models of battery cells are indistinguishable in the presence of noise - is revisited in this work. A set of six equivalent circuit models (ECMs) were chosen as a subset of West- erhoff’s generalised ECM from 2016. These six ECMs had increasing complexity, and gave a simulated output similar to that of an idealised Lithium battery impedance spec- trum. By extending the frequency range of Berthier, using methods suggested by both Mauracher & Karden, and Hasan & Scott, sets of simulated electrochemical impedance spectra (EIS) are generated. A Nelder-Mead based optimisation method, which em- ploys multiple restarts, is used to fit each ECM to the sets simulated data. The data was produced with 0%, 1%, 3% and 5% noise. The optimisations showed that all six ECMs were distinguishable at 0% noise, but as the noise increased - distinguishability is lost. Typically a 4-element ECM is shown to model the simulated data with preci- sion which is comparable to the error in the data. When optimising the ECMs against measured data (measured with an Egilent 66332A, E5270 and a Keithley 2460A) from INR and NCA batteries, it is seen that the 3-element ECMs are an adequate model. However there is some variation between the two battery chemistries. Battery ageing and the measurement system used also contribute to variation in which ECM models the data best. Further work on this project should include repeating this fitting method on different battery chemistries, and collating and fitting ECMs to a battery which is measured at different points as it ages.

year: 2023

title: Maori syllabus and the curriculum documents: A critical analysis. Part 1: Tihe Mauri Ora

authors: Crombie, Winifred

subjects: Te reo Māori

abstract: This paper presents, within the context of ongoing debates on syllabus design, a critical analysis of Tihē Mauri Ora, a syllabus document produced by the New Zealand Ministry of Education to support the teaching and learning of the Māori language in schools in New Zealand. It includes a number of suggestions in relation to any future documents prepared with similar intent.

text: Maori syllabus and the curriculum documents: A critical analysis. Part 1: Tihe Mauri Ora This paper presents, within the context of ongoing debates on syllabus design, a critical analysis of Tihē Mauri Ora, a syllabus document produced by the New Zealand Ministry of Education to support the teaching and learning of the Māori language in schools in New Zealand. It includes a number of suggestions in relation to any future documents prepared with similar intent.

year: 2001