title: Failure analysis of some Toyota Prius battery packs and potential for recovery

authors: Leijen, Peter

subjects: Toyota Prius

abstract: The Toyota Prius battery pack consists of 38 individual battery blades, each blade contains 6 NiMH cells in series. This means that each pack contains 228 NiMH cells. Each cell has the potential to fail. This report investigates the mode of failure of Prius battery packs by first analysing a number of packs in the lab, and then road testing them in a Toyota Prius. The analysis of the battery packs shows that some packs had aged “linearly”, that is in a balanced manner, such that the state of health of all blades remained similar. However, in other packs discrete blades had significantly different states of health. A pack that consists of cells that are matched in both state of health and state of charge delivers the best performance. The research also showed that the worst cell in the pack determines the overall pack performance. This was demonstrated by substituting reducedcapacity or short-circuited blades into a functioning battery pack. A vehicle with a pack consisting of 37 2400 mAh battery blades and one 1200 mAh battery blade was only able to drive 1.3 km in Electric Vehicle mode, as opposed to 2.6 km with a pack consisting of 38 2400 mAh battery blades.

text: Failure analysis of some Toyota Prius battery packs and potential for recovery The Toyota Prius battery pack consists of 38 individual battery blades, each blade contains 6 NiMH cells in series. This means that each pack contains 228 NiMH cells. Each cell has the potential to fail. This report investigates the mode of failure of Prius battery packs by first analysing a number of packs in the lab, and then road testing them in a Toyota Prius. The analysis of the battery packs shows that some packs had aged “linearly”, that is in a balanced manner, such that the state of health of all blades remained similar. However, in other packs discrete blades had significantly different states of health. A pack that consists of cells that are matched in both state of health and state of charge delivers the best performance. The research also showed that the worst cell in the pack determines the overall pack performance. This was demonstrated by substituting reducedcapacity or short-circuited blades into a functioning battery pack. A vehicle with a pack consisting of 37 2400 mAh battery blades and one 1200 mAh battery blade was only able to drive 1.3 km in Electric Vehicle mode, as opposed to 2.6 km with a pack consisting of 38 2400 mAh battery blades.

year: 2011

title: A Transnational Analysis of Elderly European Wealth Distributions: Developing and Testing New Methodologies within the new Household Financial and Consumption Survey

authors: Gaylard, David Michael

subjects: wealth

abstract: Transnational wealth inequality is an expanding field of study. However, the field has many limitations especially relating to problems of data availability, methodologies used, and the very limited pool of existing transnational literature. Alongside these basic limitations is a predominating focus on populations as a whole that correspond with a dearth of studies concerned specifically with elderly wealth distributions.
This thesis’ objective is to tackle these three problematic areas in the field, but with a specific focus on the elderly. In particular, new methodologies for analysing transnational distributions of wealth are explored and developed. These new methodologies are then tested within the Household Financial and Consumption Survey environment specifically focusing on the elderly population. This new survey provides an extensive high quality database on household financial characteristics that are pivotal to transnational and sub-cohort focused analysis.
The analysis generates several results. The first is a tested framework of a multifaceted approach for describing wealth distributions. This approach counters the widespread habit of using summary statistics which do not fully describe distributions. The results also provide evidence for two distinct macro distributions of wealth within the countries observed. These distributions represent two ends on a spectrum which contains all the possible wealth distribution shapes.
The combination of developing new methodological tools of analysis and testing them within a new data environment contribute significantly to the field. These new tools will allow for a standardised view providing deep level analysis which is still applicable to a large dataset.

text: A Transnational Analysis of Elderly European Wealth Distributions: Developing and Testing New Methodologies within the new Household Financial and Consumption Survey Transnational wealth inequality is an expanding field of study. However, the field has many limitations especially relating to problems of data availability, methodologies used, and the very limited pool of existing transnational literature. Alongside these basic limitations is a predominating focus on populations as a whole that correspond with a dearth of studies concerned specifically with elderly wealth distributions.
This thesis’ objective is to tackle these three problematic areas in the field, but with a specific focus on the elderly. In particular, new methodologies for analysing transnational distributions of wealth are explored and developed. These new methodologies are then tested within the Household Financial and Consumption Survey environment specifically focusing on the elderly population. This new survey provides an extensive high quality database on household financial characteristics that are pivotal to transnational and sub-cohort focused analysis.
The analysis generates several results. The first is a tested framework of a multifaceted approach for describing wealth distributions. This approach counters the widespread habit of using summary statistics which do not fully describe distributions. The results also provide evidence for two distinct macro distributions of wealth within the countries observed. These distributions represent two ends on a spectrum which contains all the possible wealth distribution shapes.
The combination of developing new methodological tools of analysis and testing them within a new data environment contribute significantly to the field. These new tools will allow for a standardised view providing deep level analysis which is still applicable to a large dataset.

year: 2017

title: Investigating the Social Supports of Successful Māori Undergraduate Appellants at the University of Waikato

authors: Diamond, Danielle Jade

subjects: Social Supports

abstract: Educational disparities between Māori and non-Māori tertiary students are evident in regards to participation, retention, and completion rates at secondary and tertiary levels. Instead of focusing on negative statistics, it was of interest to investigate Māori students who had failed sufficient papers to initially be denied re-entry to university study, yet continued to attain their degrees, as a result of a successful appeal. Māori undergraduate students, who had successfully appealed from 2003-2012, were recruited for my research. The availability and utilisation of social supports were investigated, along with the decision to make an appeal, the role of cultural expectations, and barriers experienced by participants. A mixed method approach was utilised in this research through use of an adapted overarching Kaupapa Māori framework, statistical analysis, and 13 interviews. My research found that social supports were beneficial for participants throughout their appeal, as they provided: emotional, instrumental, appraisal, and informational support. Although the social supports utilised by participants were satisfactory, barriers to accessing formal supports were also found, which included: perceived stigma having failed their papers, pride, as well as being whakamā. The appeal process was a beneficial intervention from the University of Waikato, which provided participants another opportunity to overcome the factors that contributed to their initial failure. Post appeal, participants implemented strategies to address and reduce their factors in order to become academically engaged. Participants were deemed to be resilient from their continued pursuit of degree attainment, implementation of their strategies, and their use of perceived social supports.

text: Investigating the Social Supports of Successful Māori Undergraduate Appellants at the University of Waikato Educational disparities between Māori and non-Māori tertiary students are evident in regards to participation, retention, and completion rates at secondary and tertiary levels. Instead of focusing on negative statistics, it was of interest to investigate Māori students who had failed sufficient papers to initially be denied re-entry to university study, yet continued to attain their degrees, as a result of a successful appeal. Māori undergraduate students, who had successfully appealed from 2003-2012, were recruited for my research. The availability and utilisation of social supports were investigated, along with the decision to make an appeal, the role of cultural expectations, and barriers experienced by participants. A mixed method approach was utilised in this research through use of an adapted overarching Kaupapa Māori framework, statistical analysis, and 13 interviews. My research found that social supports were beneficial for participants throughout their appeal, as they provided: emotional, instrumental, appraisal, and informational support. Although the social supports utilised by participants were satisfactory, barriers to accessing formal supports were also found, which included: perceived stigma having failed their papers, pride, as well as being whakamā. The appeal process was a beneficial intervention from the University of Waikato, which provided participants another opportunity to overcome the factors that contributed to their initial failure. Post appeal, participants implemented strategies to address and reduce their factors in order to become academically engaged. Participants were deemed to be resilient from their continued pursuit of degree attainment, implementation of their strategies, and their use of perceived social supports.

year: 2013