title: Finite element modeling of lead acid batteries

authors: Foster, Geoffrey James

abstract: This thesis investigates the finite element method with regard to the macrohomogeneous theory for flooded porous electrochemical cells, more specifically lead-acid cells. One- and two-dimensional finite element models are developed for flooded porous electrochemical lead acid cells. Chapter One introduces the background of the technology of lead-acid batteries, theory fundamentals, previous mathematical models for lead acid batteries, and the reason for the work. Chapter Two develops Newman’s macrohomogeneous equations for flooded porous electrodes. Chapter Three details the finite element theory, and how it is used to solve time dependent coupled non-linear partial differential equations. Chapter Four applies finite element theory to one-dimensional macrohomogeneous equations that describe lead-acid batteries. The results of the model are compared to previously published papers utilising finite difference methods. In Chapter Five, the technique is extend to two-dimensions and is validated with previously published papers of models on lead-acid batteries.

text: Finite element modeling of lead acid batteries This thesis investigates the finite element method with regard to the macrohomogeneous theory for flooded porous electrochemical cells, more specifically lead-acid cells. One- and two-dimensional finite element models are developed for flooded porous electrochemical lead acid cells. Chapter One introduces the background of the technology of lead-acid batteries, theory fundamentals, previous mathematical models for lead acid batteries, and the reason for the work. Chapter Two develops Newman’s macrohomogeneous equations for flooded porous electrodes. Chapter Three details the finite element theory, and how it is used to solve time dependent coupled non-linear partial differential equations. Chapter Four applies finite element theory to one-dimensional macrohomogeneous equations that describe lead-acid batteries. The results of the model are compared to previously published papers utilising finite difference methods. In Chapter Five, the technique is extend to two-dimensions and is validated with previously published papers of models on lead-acid batteries.

year: 1998

title: Osmotic Dehydration of New Zealand Chestnuts with and without Shell and Pellicle

authors: Pontawe, Reagan Jazmin

abstract: Osmotic dehydration offers an alternative to air-drying for reducing moisture content at ambient temperature. Of four different solutes investigated, 22% (mass basis) sodium chloride (NaCl) and 60% (mass basis) sucrose solutions were the most successful, with each achieving approximately a 10% reduction in wet basis moisture content after 8 h without significant detrimental side effects, although NaCl solutions cause noticeable darkening in the pits on the surface of the chestnuts. The presence of the shell and pellicle did not significantly affect the dehydration rate. Osmotic dehydration by NaCl or sucrose prior to mechanical shell removal produced a small increase in efficiency of the shell removal process.

text: Osmotic Dehydration of New Zealand Chestnuts with and without Shell and Pellicle Osmotic dehydration offers an alternative to air-drying for reducing moisture content at ambient temperature. Of four different solutes investigated, 22% (mass basis) sodium chloride (NaCl) and 60% (mass basis) sucrose solutions were the most successful, with each achieving approximately a 10% reduction in wet basis moisture content after 8 h without significant detrimental side effects, although NaCl solutions cause noticeable darkening in the pits on the surface of the chestnuts. The presence of the shell and pellicle did not significantly affect the dehydration rate. Osmotic dehydration by NaCl or sucrose prior to mechanical shell removal produced a small increase in efficiency of the shell removal process.

year: 2016-01-01

title: Whakarongo mai!: Transformative teaching to support Māori identity and success in a mainstream school

authors: Gilgen, Renée

subjects: Māori and mainstream education

abstract: This thesis topic emerged following a year’s teaching experience in a mainstream classroom during 2009. My cultural assumptions of being a Māori teacher in a mainstream class were challenged predominantly by a group of Māori students in the classroom. The level of despondency I felt as a result of disruptive student behaviours forced me to reassess my own socio-cultural constructs which had influenced the formation of my identity as Māori and as a mainstream teacher. The purpose of this study was to understand and explore a transformational behavioural shift which occurred within a group of Māori students during 2009 and the level of support they felt they received as Māori within a mainstream classroom context. National and international literature demonstrates that transformative praxis is both reflective and active. Successful inclusive teaching requires a personal and professional commitment to firstly understand individual cultural constructs to then better understand how learners are perceived and positioned. Culturally responsive pedagogy ensures that all students’ cultural practices and values are acknowledged and included into classroom teaching and learning programmes. In a New Zealand mainstream context, the Treaty of Waitangi principles of ‘partnership’, ‘participation’ and ‘protection’ serve as a bi-cultural ‘power-sharing’ metaphor from which all mainstream teachers of Māori students can successfully encourage student voice and foster reciprocal teaching and learning relationships. My use of qualitative research methods and kaupapa Māori principles to guide the research process ensured that Māori cultural protocols and practices were honoured. My role as a Māori insider researcher meant that my relationship with the participants was already established. Our reflections as Māori students and a Māori teacher in a mainstream classroom context were based from shared teaching and learning experiences during 2009. Researcher reflexivity has ensured that the research integrity, validity and reliability have remained high. The research findings present the reflections of both the participants and researcher as Māori students and as a Māori teacher during 2009. Participants believed that teaching and learning programmes which incorporated te reo Māori served to honour their identity as Māori. However, their awareness of participating with tikanga Māori principles of whānaungatanga (relationships), manaakitanga (caring), ako (reciprocity) and aroha (respect) embedded within classroom activities that were exclusively in English, were not identified as being relevant to them as Māori. Similarly, the Treaty of Waitangi principles lacked transparency within my teaching pedagogy. Two key implications for teaching and learning in mainstream schools and classrooms were identified. Firstly, there is an urgency for mainstream school managers, leaders and teachers to develop an understanding of the Treaty of Waitangi and its significance for the 21st Century mainstream teacher and learner. A bi-cultural understanding of ourselves as treaty partners support Māori cultural values and practices within increasingly diverse mainstream school and classroom contexts. Māori students‟ success becomes the responsibility of all mainstream managers, leaders and teachers as treaty partners. Secondly, inclusive and culturally responsive pedagogy demonstrates that Māori and non-Māori mainstream teachers are capable of effectively engaging Māori students with learning while acknowledging and reaffirming their cultural identity and language as tangata whenua. Overall, my commitment for Māori students to be supported as Māori within mainstream school and classroom context has been enriched and strengthened as a result of this research study. The cultural and professional tensions I have experienced in mainstream contexts have challenged the socio-cultural constructs that I had accepted as being my cultural ‘norm.’

text: Whakarongo mai!: Transformative teaching to support Māori identity and success in a mainstream school This thesis topic emerged following a year’s teaching experience in a mainstream classroom during 2009. My cultural assumptions of being a Māori teacher in a mainstream class were challenged predominantly by a group of Māori students in the classroom. The level of despondency I felt as a result of disruptive student behaviours forced me to reassess my own socio-cultural constructs which had influenced the formation of my identity as Māori and as a mainstream teacher. The purpose of this study was to understand and explore a transformational behavioural shift which occurred within a group of Māori students during 2009 and the level of support they felt they received as Māori within a mainstream classroom context. National and international literature demonstrates that transformative praxis is both reflective and active. Successful inclusive teaching requires a personal and professional commitment to firstly understand individual cultural constructs to then better understand how learners are perceived and positioned. Culturally responsive pedagogy ensures that all students’ cultural practices and values are acknowledged and included into classroom teaching and learning programmes. In a New Zealand mainstream context, the Treaty of Waitangi principles of ‘partnership’, ‘participation’ and ‘protection’ serve as a bi-cultural ‘power-sharing’ metaphor from which all mainstream teachers of Māori students can successfully encourage student voice and foster reciprocal teaching and learning relationships. My use of qualitative research methods and kaupapa Māori principles to guide the research process ensured that Māori cultural protocols and practices were honoured. My role as a Māori insider researcher meant that my relationship with the participants was already established. Our reflections as Māori students and a Māori teacher in a mainstream classroom context were based from shared teaching and learning experiences during 2009. Researcher reflexivity has ensured that the research integrity, validity and reliability have remained high. The research findings present the reflections of both the participants and researcher as Māori students and as a Māori teacher during 2009. Participants believed that teaching and learning programmes which incorporated te reo Māori served to honour their identity as Māori. However, their awareness of participating with tikanga Māori principles of whānaungatanga (relationships), manaakitanga (caring), ako (reciprocity) and aroha (respect) embedded within classroom activities that were exclusively in English, were not identified as being relevant to them as Māori. Similarly, the Treaty of Waitangi principles lacked transparency within my teaching pedagogy. Two key implications for teaching and learning in mainstream schools and classrooms were identified. Firstly, there is an urgency for mainstream school managers, leaders and teachers to develop an understanding of the Treaty of Waitangi and its significance for the 21st Century mainstream teacher and learner. A bi-cultural understanding of ourselves as treaty partners support Māori cultural values and practices within increasingly diverse mainstream school and classroom contexts. Māori students‟ success becomes the responsibility of all mainstream managers, leaders and teachers as treaty partners. Secondly, inclusive and culturally responsive pedagogy demonstrates that Māori and non-Māori mainstream teachers are capable of effectively engaging Māori students with learning while acknowledging and reaffirming their cultural identity and language as tangata whenua. Overall, my commitment for Māori students to be supported as Māori within mainstream school and classroom context has been enriched and strengthened as a result of this research study. The cultural and professional tensions I have experienced in mainstream contexts have challenged the socio-cultural constructs that I had accepted as being my cultural ‘norm.’

year: 2010