title: Early prediction of Li-ion cell failure from EIS derived from current-voltage time series

authors: Wilson, Marcus T.

abstract: The ability to reliably detect the forthcoming failure of a rechargeable cell without removing it from its normal operating environment remains a significant goal in battery research. In this work we have cycled in the laboratory a previously-aged 3.2 A h, 3.6 V 18650 INR LiNixMnyCo 1 − x − y O2 cell for 300 d until failure was apparent, using a current waveform representative of use in an electric vehicle application. Electrochemical impedance spectroscopy (EIS) down to 5 µHz was also performed on the cell as a ‘gold-standard’ measure, at the beginning, end and part way through the cycling. Analysis of voltage and current time series data using both parametric (equivalent circuit model) and non-parametric (wavelet-based analysis) approaches allowed us to successfully reconstruct the EIS data. As the battery aged, impedance gradually increased at frequencies between 10−4 Hz—10−1 Hz. The increase accelerated around 50 d before the battery ultimately failed. The acceleration in rate of change of impedance was detectable while the cycle efficiency remained high, indicating that a user of the cell would be unlikely to detect any change in the cell based on its performance or by common measures of state-of-health. The results imply upcoming failure may be detectable from time series analysis weeks before any noticeable drop in cell performance.

text: Early prediction of Li-ion cell failure from EIS derived from current-voltage time series The ability to reliably detect the forthcoming failure of a rechargeable cell without removing it from its normal operating environment remains a significant goal in battery research. In this work we have cycled in the laboratory a previously-aged 3.2 A h, 3.6 V 18650 INR LiNixMnyCo 1 − x − y O2 cell for 300 d until failure was apparent, using a current waveform representative of use in an electric vehicle application. Electrochemical impedance spectroscopy (EIS) down to 5 µHz was also performed on the cell as a ‘gold-standard’ measure, at the beginning, end and part way through the cycling. Analysis of voltage and current time series data using both parametric (equivalent circuit model) and non-parametric (wavelet-based analysis) approaches allowed us to successfully reconstruct the EIS data. As the battery aged, impedance gradually increased at frequencies between 10−4 Hz—10−1 Hz. The increase accelerated around 50 d before the battery ultimately failed. The acceleration in rate of change of impedance was detectable while the cycle efficiency remained high, indicating that a user of the cell would be unlikely to detect any change in the cell based on its performance or by common measures of state-of-health. The results imply upcoming failure may be detectable from time series analysis weeks before any noticeable drop in cell performance.

year: 2025

title: Towards a framework of deep diversity: Identity and invisibility in the Indian diaspora in New Zealand

authors: Nachowitz, Todd

subjects: Indian diaspora

abstract: Using the Indian diaspora in New Zealand as a case study, this thesis examines how state categorisation practices and nation building narratives have constructed and racialised migrant minorities, such as Indians, in particular ways. It does so through a review of the historical settlement narrative and census records that have tended to erase early ethnic minority presence from what is seen as a predominantly bicultural encounter. 

Aotearoan colonial society has tended to render early Indian presence in New Zealand invisible. This pattern remains perceptible in the prolonged use of homogenising ethnic categories utilised throughout the history of the New Zealand census that obfuscate the extent of ethnic minority diversification with specific reference to the Indian community. 

The thesis critiques state constructions of ethnic identity through (1) the presentation of alternative historical narratives that more appropriately demonstrate the presence of non-Māori non-European minorities at first contact; (2) an examination of minority reporting in the New Zealand census during the period of early European settlement; and (3) an analysis of data from a survey of the Indian community in New Zealand. The survey data on self-reported experiences of discrimination underscore the importance of ethnic self-identification and the use of more heterogeneous categories for appropriate minority recognition. 

At a theoretical level, the thesis outlines a novel framework for diversity governance, known as deep diversity, which is informed by an interdisciplinary methodological and theoretical approach that draws on the disciplines of anthropology, demography, history, and policy studies. This framework rethinks current policy approaches that position minorities as beneficiaries of policies designed for their social uplift and integration into majority society, and instead places the onus of social integration on both minorities and majorities. The framework is applied to an analysis of qualitative data from historical sources that fundamentally question New Zealand’s existing bicultural settlement narrative; to quantitative data from both historical and contemporary census records; and to a self-administered predominantly web-based survey of 1,124 Indian respondents using a snowball sampling method.

This thesis presents an alternative historical settlement narrative that positions Indians as participating, along with Europeans, in first contact encounters with Māori in Aotearoa. Past and present census analysis also reveals the extent of historic Indian invisibility, and demonstrates continued state use of enumeration techniques that obscure and homogenise the diversity that exists within the Indian population. The survey results focus on the themes of identity and discrimination, the analysis of which offers insights about the importance of ethnic self-identification, the continued presence of discrimination, and the use of more heterogeneous categories for appropriate minority recognition. Specific survey results show that respondents, while identifying as ‘Indian’ on the census, favour terms that cite hyphenated nationality or ethnicity (e.g. Kiwi-Indian, Indo-Fijian) or regional, religious, linguistic and country of birth identifiers, as significant forms of self-identification. Results on discrimination demonstrate that 48.4% of survey respondents reported being the target of a discrimination event in New Zealand (86.9% of whom are migrants, while 13.1% were born in New Zealand). When queried about the presence of discrimination, 90.7% of respondents believe that racism and discrimination currently exist within New Zealand society, while only 9.3% believe that it does not exist. 

Minority invisibility contributes to social discrimination, and helps perpetuate the shallow diversity management practices in use today. More attention to the importance of appropriate minority self-identification and accommodation, involving majorities in minority integration programmes, and institutional support for a shared national identity, could all help facilitate and promote vital social cohesion strategies in New Zealand. The deep diversity framework articulated in this thesis offers an alternative vision for diversity governance and social cohesion that is appropriate for western liberal democracies with highly pluralised societies such as New Zealand.

text: Towards a framework of deep diversity: Identity and invisibility in the Indian diaspora in New Zealand Using the Indian diaspora in New Zealand as a case study, this thesis examines how state categorisation practices and nation building narratives have constructed and racialised migrant minorities, such as Indians, in particular ways. It does so through a review of the historical settlement narrative and census records that have tended to erase early ethnic minority presence from what is seen as a predominantly bicultural encounter. 

Aotearoan colonial society has tended to render early Indian presence in New Zealand invisible. This pattern remains perceptible in the prolonged use of homogenising ethnic categories utilised throughout the history of the New Zealand census that obfuscate the extent of ethnic minority diversification with specific reference to the Indian community. 

The thesis critiques state constructions of ethnic identity through (1) the presentation of alternative historical narratives that more appropriately demonstrate the presence of non-Māori non-European minorities at first contact; (2) an examination of minority reporting in the New Zealand census during the period of early European settlement; and (3) an analysis of data from a survey of the Indian community in New Zealand. The survey data on self-reported experiences of discrimination underscore the importance of ethnic self-identification and the use of more heterogeneous categories for appropriate minority recognition. 

At a theoretical level, the thesis outlines a novel framework for diversity governance, known as deep diversity, which is informed by an interdisciplinary methodological and theoretical approach that draws on the disciplines of anthropology, demography, history, and policy studies. This framework rethinks current policy approaches that position minorities as beneficiaries of policies designed for their social uplift and integration into majority society, and instead places the onus of social integration on both minorities and majorities. The framework is applied to an analysis of qualitative data from historical sources that fundamentally question New Zealand’s existing bicultural settlement narrative; to quantitative data from both historical and contemporary census records; and to a self-administered predominantly web-based survey of 1,124 Indian respondents using a snowball sampling method.

This thesis presents an alternative historical settlement narrative that positions Indians as participating, along with Europeans, in first contact encounters with Māori in Aotearoa. Past and present census analysis also reveals the extent of historic Indian invisibility, and demonstrates continued state use of enumeration techniques that obscure and homogenise the diversity that exists within the Indian population. The survey results focus on the themes of identity and discrimination, the analysis of which offers insights about the importance of ethnic self-identification, the continued presence of discrimination, and the use of more heterogeneous categories for appropriate minority recognition. Specific survey results show that respondents, while identifying as ‘Indian’ on the census, favour terms that cite hyphenated nationality or ethnicity (e.g. Kiwi-Indian, Indo-Fijian) or regional, religious, linguistic and country of birth identifiers, as significant forms of self-identification. Results on discrimination demonstrate that 48.4% of survey respondents reported being the target of a discrimination event in New Zealand (86.9% of whom are migrants, while 13.1% were born in New Zealand). When queried about the presence of discrimination, 90.7% of respondents believe that racism and discrimination currently exist within New Zealand society, while only 9.3% believe that it does not exist. 

Minority invisibility contributes to social discrimination, and helps perpetuate the shallow diversity management practices in use today. More attention to the importance of appropriate minority self-identification and accommodation, involving majorities in minority integration programmes, and institutional support for a shared national identity, could all help facilitate and promote vital social cohesion strategies in New Zealand. The deep diversity framework articulated in this thesis offers an alternative vision for diversity governance and social cohesion that is appropriate for western liberal democracies with highly pluralised societies such as New Zealand.

year: 2015

title: Indigenous human rights and knowledge in archives, museums, and libraries: Some international perspectives with specific reference to New Zealand and Canada

authors: Morse, Bradford W.

subjects: indigenous records

abstract: This article highlights the extent to which international law has changed rapidly in recent years in relation to the rights of Indigenous peoples generally and in particular how this impacts upon the legal status of traditional knowledge and culture. It reviews the recognition of the unique legal status of Māori in Aotearoa and Aboriginal peoples in Canada in relation to self-determination and how their changing place within these nations are affecting the operations of museums, libraries, and archives as case studies, illustrating some of the key legal and practical challenges that now impinge upon the work of archivists and related professionals in many countries.

text: Indigenous human rights and knowledge in archives, museums, and libraries: Some international perspectives with specific reference to New Zealand and Canada This article highlights the extent to which international law has changed rapidly in recent years in relation to the rights of Indigenous peoples generally and in particular how this impacts upon the legal status of traditional knowledge and culture. It reviews the recognition of the unique legal status of Māori in Aotearoa and Aboriginal peoples in Canada in relation to self-determination and how their changing place within these nations are affecting the operations of museums, libraries, and archives as case studies, illustrating some of the key legal and practical challenges that now impinge upon the work of archivists and related professionals in many countries.

year: 2012