title: Investigation of a discus-milling process using a powder mixture of Al and TiO₂

authors: Liu, Z. G.

abstract: In this study, a powder mixture of Al and TiO₂ was employed to investigate the milling process in a discus mill. In this first report on this novel mechanical mill, several variables, including the milling time and powder charge and their effects on the microstructural evolution of powder particles, are monitored and studied. The study reveals that the dominant parameters of the milling process are the milling time and the starting powder charge, similar to the other high-energy ball-milling processes. The longer the milling time and the smaller the starting powder charge, the more homogeneous the mixing and the finer the microstructure of the powder particles. The reaction between Al and TiO₂ was not observed with a milling period as long as 6 hours, for the present materials. However, the reaction between Al and TiO₂, during the subsequent heat treatment, is influenced by the milling condition. The powders with the longer milling times and finer mixing microstructures also form a finer microstructure, after the reaction between Al and TiO₂  during heat treatment. The methods for achieving an optimal milling efficiency for the Al- TiO₂  system are discussed.

text: Investigation of a discus-milling process using a powder mixture of Al and TiO₂ In this study, a powder mixture of Al and TiO₂ was employed to investigate the milling process in a discus mill. In this first report on this novel mechanical mill, several variables, including the milling time and powder charge and their effects on the microstructural evolution of powder particles, are monitored and studied. The study reveals that the dominant parameters of the milling process are the milling time and the starting powder charge, similar to the other high-energy ball-milling processes. The longer the milling time and the smaller the starting powder charge, the more homogeneous the mixing and the finer the microstructure of the powder particles. The reaction between Al and TiO₂ was not observed with a milling period as long as 6 hours, for the present materials. However, the reaction between Al and TiO₂, during the subsequent heat treatment, is influenced by the milling condition. The powders with the longer milling times and finer mixing microstructures also form a finer microstructure, after the reaction between Al and TiO₂  during heat treatment. The methods for achieving an optimal milling efficiency for the Al- TiO₂  system are discussed.

year: 2006

title: Promoting pedagogical content knowledge development for early career secondary teachers in science and technology using content representations

authors: Williams, P. John

subjects: CoRE

abstract: Background: This research addressed the key area of early career teacher education and aimed to explore the use of a 'content representation' (CoRe) as a mediational tool to develop early career secondary teacher pedagogical content knowledge (PCK). This study was situated in the subject areas of science and technology, where sound teacher knowledge is particularly important to student engagement.Purpose: The study was designed to examine whether such a tool (a CoRe), co-designed by an early career secondary teacher with expert content and pedagogy specialists, can enhance the PCK of early career teachers. The research questions were: How can experts in content and pedagogy work together with early career teachers to develop one science topic CoRe and one technology topic CoRe to support the development of PCK for early career secondary teachers? How does the use of a collaboratively designed CoRe affect the planning of an early career secondary teacher in science or technology? How has engagement in the development and use of an expert-informed CoRe developed an early career teacher's PCK?Sample: The research design incorporated a unique partnership between two expert classroom teachers, two content experts, four early career teachers, and four researchers experienced in science and technology education.Design: This study employed an interpretivist-based methodology and an action research approach within a four-case study design. Data were gathered using qualitative research methods focused on semi-structured interviews, observations and document analysis.Results: The study indicated that CoRes, developed through this collaborative process, helped the early career teachers focus on the big picture of the topic, emphasize particularly relevant areas of content and consider alternative ways of planning for their teaching.Conclusions: This paper presents an analysis of the process of CoRe development by the teacher-expert partnerships and the effect that had on the early career teachers' PCK. In addition, as the same tools and methodology were applied to both a science and a technology teaching context, differences between the two learning areas are discussed.

text: Promoting pedagogical content knowledge development for early career secondary teachers in science and technology using content representations Background: This research addressed the key area of early career teacher education and aimed to explore the use of a 'content representation' (CoRe) as a mediational tool to develop early career secondary teacher pedagogical content knowledge (PCK). This study was situated in the subject areas of science and technology, where sound teacher knowledge is particularly important to student engagement.Purpose: The study was designed to examine whether such a tool (a CoRe), co-designed by an early career secondary teacher with expert content and pedagogy specialists, can enhance the PCK of early career teachers. The research questions were: How can experts in content and pedagogy work together with early career teachers to develop one science topic CoRe and one technology topic CoRe to support the development of PCK for early career secondary teachers? How does the use of a collaboratively designed CoRe affect the planning of an early career secondary teacher in science or technology? How has engagement in the development and use of an expert-informed CoRe developed an early career teacher's PCK?Sample: The research design incorporated a unique partnership between two expert classroom teachers, two content experts, four early career teachers, and four researchers experienced in science and technology education.Design: This study employed an interpretivist-based methodology and an action research approach within a four-case study design. Data were gathered using qualitative research methods focused on semi-structured interviews, observations and document analysis.Results: The study indicated that CoRes, developed through this collaborative process, helped the early career teachers focus on the big picture of the topic, emphasize particularly relevant areas of content and consider alternative ways of planning for their teaching.Conclusions: This paper presents an analysis of the process of CoRe development by the teacher-expert partnerships and the effect that had on the early career teachers' PCK. In addition, as the same tools and methodology were applied to both a science and a technology teaching context, differences between the two learning areas are discussed.

year: 2012

title: Reclaiming Kaitiakitanga : An intergenerational perspective of Kaitiakitanga within Te Parawhau

authors: Walker, Erana

subjects: Kaitiakitanga

abstract: Kaitiakitanga is a concept that is utilised widely throughout the Māori world for the protection and preservation of cultural aspects to Māori. Through years of application by westernised mainstream processes the value has largely been restricted to the realms of environmental protection. This restriction has often been the result of misinterpretation of Kaitiakitanga and its relevance as a concept to Māori. The purpose of the thesis is to question how the perspective of Kaitiakitanga is constructed in the minds of representatives from the hapū of Te Parawhau. To test for variance, the research spans across two generations of hapū members. Using Whakawhiti Kōrero for data collection as well as Kaupapa Māori methodology as guidance, the thesis explores perspectives of two generations of Te Parawhau descendants around Kaitiakitanga and how it can be developed to aid in the growth and prosperity of the hapū. Key themes highlighted by the analysis encompass ideas of connectedness as well as spiritual, physical, environmental and human elements of responsibility and obligation. The thesis introduces a distinct Te Parawhau analytical framework for its analysis of rich kōrero by hapū members in relation to Kaitiakitanga. Through this framework the value of Kaitiakitanga is tested for relevance to Te Parawhau and its future development. The world view of Te Parawhau has formed the basis of participant perspectives around Kaitiakitanga and leads the researcher to consider that such knowledge is important to the future functionality of Māori value’s. The thesis concludes to show that there are indeed differences in application and perspectives of Kaitiakitanga within the hapū of Te Parawhau.

text: Reclaiming Kaitiakitanga : An intergenerational perspective of Kaitiakitanga within Te Parawhau Kaitiakitanga is a concept that is utilised widely throughout the Māori world for the protection and preservation of cultural aspects to Māori. Through years of application by westernised mainstream processes the value has largely been restricted to the realms of environmental protection. This restriction has often been the result of misinterpretation of Kaitiakitanga and its relevance as a concept to Māori. The purpose of the thesis is to question how the perspective of Kaitiakitanga is constructed in the minds of representatives from the hapū of Te Parawhau. To test for variance, the research spans across two generations of hapū members. Using Whakawhiti Kōrero for data collection as well as Kaupapa Māori methodology as guidance, the thesis explores perspectives of two generations of Te Parawhau descendants around Kaitiakitanga and how it can be developed to aid in the growth and prosperity of the hapū. Key themes highlighted by the analysis encompass ideas of connectedness as well as spiritual, physical, environmental and human elements of responsibility and obligation. The thesis introduces a distinct Te Parawhau analytical framework for its analysis of rich kōrero by hapū members in relation to Kaitiakitanga. Through this framework the value of Kaitiakitanga is tested for relevance to Te Parawhau and its future development. The world view of Te Parawhau has formed the basis of participant perspectives around Kaitiakitanga and leads the researcher to consider that such knowledge is important to the future functionality of Māori value’s. The thesis concludes to show that there are indeed differences in application and perspectives of Kaitiakitanga within the hapū of Te Parawhau.

year: 2016