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: An assessment of endocrine disrupting potential of a New Zealand pulp and paper mill effluent using rainbow trout Oncorhynchus mykiss and mosquitofish Gambusia affinis

authors: Ellis, Rosanne Jane

abstract: I examined the effects of a modern mixed thermo-mechanical pulp/bleached kraft (TMP/BK) mill effluent on potential reproductive-endocrine impacts on two fish species, rainbow trout and mosquitofish using a combined approach of laboratory and on-site mesocosm exposures. Rainbow trout Oncorhynchus mykiss were utilised in a combination of early life stage and juvenile (+1 year) long- and short term exposures. Exposure of rainbow trout eggs to 15% (v/v) effluent until 10.5 months of age had no effect on fertilisation, hatching success, time to hatch, time to swim-up, juvenile mortality rate, growth and development. Juvenile (+1 year) rainbow trout were exposed to secondary treated TMP /BK mill effluent at a range of concentrations from environmentally relevant (10%) to 70% (v/v) in two exposure studies. During both 21- and 56-day exposures to 10% and 30% (v/v) effluent, no statistically significant impacts on spleen weight, liver weight, condition factor, and circulating testosterone and pregnenolone levels were observed. Consequently, vitellogenin induction as well as the expression of the estrogen receptor in juvenile males was not observed in either experiment. Statistically significant differences in spleen and liver size as well as high experimental mortality were observed in the 70% (v/v) effluent 21-day treatment and was linked to an atypically high suspended solids load. Two mosquitofish Gambusia affinis experiments were conducted, both consisted of a 21-day exposure using adult females. The first experiment was a multiple concentration exposure to primary and secondary treated effluents. A statistically significant masculinisation response (gonopodial development) was noted in all effluent treatments. However, secondary treatment of the effluent resulted in a significant decrease in gonopodial development. The second experiment focused on filtered and unfiltered secondary treated effluent at an environmentally relevant concentration (15%). Filtration of the treated effluent resulted in the almost complete elimination of the female masculinisation response. In all experiments, male mating behaviour was observed in the masculinised female mosquitofish. I concluded that a significant species difference regarding sensitivity to reproductive-endocrine modulating compounds occurred following exposure to a mixed TMP/BKM effluent. In addition, the data suggest that the compounds of concern are bound to solid matter within the effluent and these effluents have the potential to exert effects through an androgen-like mode of action.

text: An assessment of endocrine disrupting potential of a New Zealand pulp and paper mill effluent using rainbow trout Oncorhynchus mykiss and mosquitofish Gambusia affinis I examined the effects of a modern mixed thermo-mechanical pulp/bleached kraft (TMP/BK) mill effluent on potential reproductive-endocrine impacts on two fish species, rainbow trout and mosquitofish using a combined approach of laboratory and on-site mesocosm exposures. Rainbow trout Oncorhynchus mykiss were utilised in a combination of early life stage and juvenile (+1 year) long- and short term exposures. Exposure of rainbow trout eggs to 15% (v/v) effluent until 10.5 months of age had no effect on fertilisation, hatching success, time to hatch, time to swim-up, juvenile mortality rate, growth and development. Juvenile (+1 year) rainbow trout were exposed to secondary treated TMP /BK mill effluent at a range of concentrations from environmentally relevant (10%) to 70% (v/v) in two exposure studies. During both 21- and 56-day exposures to 10% and 30% (v/v) effluent, no statistically significant impacts on spleen weight, liver weight, condition factor, and circulating testosterone and pregnenolone levels were observed. Consequently, vitellogenin induction as well as the expression of the estrogen receptor in juvenile males was not observed in either experiment. Statistically significant differences in spleen and liver size as well as high experimental mortality were observed in the 70% (v/v) effluent 21-day treatment and was linked to an atypically high suspended solids load. Two mosquitofish Gambusia affinis experiments were conducted, both consisted of a 21-day exposure using adult females. The first experiment was a multiple concentration exposure to primary and secondary treated effluents. A statistically significant masculinisation response (gonopodial development) was noted in all effluent treatments. However, secondary treatment of the effluent resulted in a significant decrease in gonopodial development. The second experiment focused on filtered and unfiltered secondary treated effluent at an environmentally relevant concentration (15%). Filtration of the treated effluent resulted in the almost complete elimination of the female masculinisation response. In all experiments, male mating behaviour was observed in the masculinised female mosquitofish. I concluded that a significant species difference regarding sensitivity to reproductive-endocrine modulating compounds occurred following exposure to a mixed TMP/BKM effluent. In addition, the data suggest that the compounds of concern are bound to solid matter within the effluent and these effluents have the potential to exert effects through an androgen-like mode of action.

year: 2001

title: Pākehā Roots: Is claiming a Pākehā identity based on ethnic heritage or ethical choice?

authors: Green, Lynda

subjects: Authenticity

abstract: Development of a Pākehā identity has been an ongoing process since the first influx of people from the Northern Hemisphere set foot on the shores of Aotearoa. Originally the term Pākehā served as a generic term to distinguish early European colonisers from the Indigenous population who came to be known under the generic term of Māori. Both of these terms separated two groups of residents that have come to be known under the broader title of New Zealander. 

Chapter 2 begins with providing definitions from a range of sources describing some origins and definitions of the term Pākehā, discussion around the appropriateness of the term and how it can be used in our current timeframe to show empathy with Māori and their struggle for self-determination. A brief overview of human migration to the British Isles then the resulting migration to Aotearoa provides historical context to our pre-Pākehā heritage. Following this is a snapshot of some of our earliest Pākehā settlers which leads into the extent our governing bodies enlisted assisted immigrants to populate and provide infrastructure for this new colony of the British Empire. 

Chapter 3 delves into the angst-ridden territory of authentic existence championed through the existential philosophical movement. Tempered with a more compassionate approach from communitarian philosophy we are provided with a means to explore the many layers that build not only individual identity, but a collective identity also. Evidence is offered for the accommodation of the similarities, and more importantly differences we all experience in our wider relationships. Finally, focus is narrowed to specific issues attached to identifying as Pākehā in Aotearoa.

Underpinning this research are the nine semi-structured interviews which have provided tangible evidence of the complex elements accompanying the decision to self-identify as Pākehā (Chapter 4).  The very nature of identifying as Pākehā, as illustrated through the interview is not straightforward eliciting responses ranging from abundantly clear, to confusing and to contentious.  

The sheer diversity of responses generated an initial observance that, if this level of diversity in defining the term Pākehā is shown by nine people, how much more diversity would be operating throughout the general population. Here we can see how the basic premise of existential philosophy, that is, there is no essential nature to our existence, can be applied to attempting to seek a definition of being Pākehā that encapsulates all of the possible elements. What became abundantly apparent was the heartening feeling of most people striving for a sense of connectedness, on various levels, and a sense of belonging to this country we all call home.

text: Pākehā Roots: Is claiming a Pākehā identity based on ethnic heritage or ethical choice? Development of a Pākehā identity has been an ongoing process since the first influx of people from the Northern Hemisphere set foot on the shores of Aotearoa. Originally the term Pākehā served as a generic term to distinguish early European colonisers from the Indigenous population who came to be known under the generic term of Māori. Both of these terms separated two groups of residents that have come to be known under the broader title of New Zealander. 

Chapter 2 begins with providing definitions from a range of sources describing some origins and definitions of the term Pākehā, discussion around the appropriateness of the term and how it can be used in our current timeframe to show empathy with Māori and their struggle for self-determination. A brief overview of human migration to the British Isles then the resulting migration to Aotearoa provides historical context to our pre-Pākehā heritage. Following this is a snapshot of some of our earliest Pākehā settlers which leads into the extent our governing bodies enlisted assisted immigrants to populate and provide infrastructure for this new colony of the British Empire. 

Chapter 3 delves into the angst-ridden territory of authentic existence championed through the existential philosophical movement. Tempered with a more compassionate approach from communitarian philosophy we are provided with a means to explore the many layers that build not only individual identity, but a collective identity also. Evidence is offered for the accommodation of the similarities, and more importantly differences we all experience in our wider relationships. Finally, focus is narrowed to specific issues attached to identifying as Pākehā in Aotearoa.

Underpinning this research are the nine semi-structured interviews which have provided tangible evidence of the complex elements accompanying the decision to self-identify as Pākehā (Chapter 4).  The very nature of identifying as Pākehā, as illustrated through the interview is not straightforward eliciting responses ranging from abundantly clear, to confusing and to contentious.  

The sheer diversity of responses generated an initial observance that, if this level of diversity in defining the term Pākehā is shown by nine people, how much more diversity would be operating throughout the general population. Here we can see how the basic premise of existential philosophy, that is, there is no essential nature to our existence, can be applied to attempting to seek a definition of being Pākehā that encapsulates all of the possible elements. What became abundantly apparent was the heartening feeling of most people striving for a sense of connectedness, on various levels, and a sense of belonging to this country we all call home.

year: 2014