title: A systems approach to physics education at first year university level

authors: Osborne, Roger John

abstract: The research work described in this thesis evaluates the contribution which a systems approach can make to the development of an instructional programme. The thesis investigated is that such an approach can lead directly to a better understanding of the instructional process in a given subject and thus indirectly to more efficient instruction in that area.

The term systems approach is first reconsidered and a view is established which is broader than that normally considered in education. Two distinct aspects of this systems approach are identified-an “applied” aspect and a “basic” aspect. With respect to curriculum development and analysis, the applied aspect involves the design, development and evaluation of a learning programme. Here evaluation includes the development of specific instruments and procedures which can lead directly to the improvement of the learning programme. The basic aspect involves the investigation of the developed learning system in terms of models which explore the interactions between an instructional programme and the students involved. 

These two aspects of the systems approach are then applied to the development and analysis of an instructional programme in physics at the first year university level. The determination of objectives, the design of instruction and the evaluation of instructional methods are detailed. Since the objectives of the instruction are generalized learner objectives, particular consideration is given to the measurement of student attainment with respect to these objectives. Four distinct aspects of student attainment are identified by the use of principal components analyses. 

In terms of the basic aspect of the systems approach, both general diagrammatic models and specific statistical models are developed to obtain a better understanding of the particular first year university learning system under consideration. Various statistical models, which attempt to establish and clarify interrelationships within the instructional programme are explored. Path analysis is used as the major statistical technique.

Through the application of the systems view to the development and analysis of the first year university physics instructional programme, it has been possible to see some of the potential, some of the problems, and some of the limitations of the systems approach to physics education. In particular the systems approach, as considered in this thesis, appears to provide a broad and comprehensive framework on which to base curriculum work and to provide a viewpoint which leads to an emphasis on particularly important aspects of an instructional system-namely the objectives, the teaching methods, the assessment procedures and the feedback mechanisms within the system

text: A systems approach to physics education at first year university level The research work described in this thesis evaluates the contribution which a systems approach can make to the development of an instructional programme. The thesis investigated is that such an approach can lead directly to a better understanding of the instructional process in a given subject and thus indirectly to more efficient instruction in that area.

The term systems approach is first reconsidered and a view is established which is broader than that normally considered in education. Two distinct aspects of this systems approach are identified-an “applied” aspect and a “basic” aspect. With respect to curriculum development and analysis, the applied aspect involves the design, development and evaluation of a learning programme. Here evaluation includes the development of specific instruments and procedures which can lead directly to the improvement of the learning programme. The basic aspect involves the investigation of the developed learning system in terms of models which explore the interactions between an instructional programme and the students involved. 

These two aspects of the systems approach are then applied to the development and analysis of an instructional programme in physics at the first year university level. The determination of objectives, the design of instruction and the evaluation of instructional methods are detailed. Since the objectives of the instruction are generalized learner objectives, particular consideration is given to the measurement of student attainment with respect to these objectives. Four distinct aspects of student attainment are identified by the use of principal components analyses. 

In terms of the basic aspect of the systems approach, both general diagrammatic models and specific statistical models are developed to obtain a better understanding of the particular first year university learning system under consideration. Various statistical models, which attempt to establish and clarify interrelationships within the instructional programme are explored. Path analysis is used as the major statistical technique.

Through the application of the systems view to the development and analysis of the first year university physics instructional programme, it has been possible to see some of the potential, some of the problems, and some of the limitations of the systems approach to physics education. In particular the systems approach, as considered in this thesis, appears to provide a broad and comprehensive framework on which to base curriculum work and to provide a viewpoint which leads to an emphasis on particularly important aspects of an instructional system-namely the objectives, the teaching methods, the assessment procedures and the feedback mechanisms within the system

year: 1976

title: The Effect of Grain Refinement on the Castability of Magnesium-Aluminium Alloys

authors: Loughnane, Timothy Kevin

subjects: Magnesium

abstract: Rapidly increasing fuel prices and global pressures to reduce the harmful effects of vehicle emissions are forcing vehicle manufacturers to look at alternative materials to reduce the mass of the vehicles they produce. This has led to an increase in the research and development of magnesium alloys for use in automotive applications, and the methods used to produce them. With a density two-thirds that of aluminium alloys, and one quarter that of steel, magnesium alloys are continually being investigated as possible replacements for the production of automotive castings such as wheels and engine blocks. However, there is presently a lack of understanding of the effects of common alloy additions that refine the as-cast microstructure on the castability of the casting alloys in question.

The most popular magnesium alloys for large automotive castings are based on the magnesium-aluminium alloy system. For the work presented in this thesis, two of the most common Mg-Al alloys, AZ91E and AM60B, were chosen to determine the effect of grain refinement on the castability of Mg-Al alloys. An experimental mould has been designed and developed to emulate the geometry, filling, and solidification of an alloy wheel casting. Two different grain refiners were investigated at varying addition levels to determine the effect of different levels of grain refinement on the castability of the two alloys. Castability, defined as the ability to produce sound castings from a particular alloy, has been assessed through visual examination of external casting defects, X-ray radiography of internal defects, as well as grain size and porosity level analysis of all samples produced.

It has been found that for both AZ91E and AM60B, an increase in the level of grain refinement achieved lead to an increase in the occurrence and severity of the surface slumping defect in the castings produced. Conversely, increased levels of grain refinement were found to reduce or totally eliminate the occurrence of the hot tearing defect in both alloys.

Contrary to popular belief, grain refinement was found to increase the level of internal shrinkage porosity in the Mg-Al castings. This was especially the case in the poorly fed regions of the casting, such as the junction between the spoke and rim sections. This is due to the increased reliance on interdendritic feeding of liquid to compensate for shrinkage during the latter stages of solidification in such areas, where solidification does not proceed directionally towards the feeding reservoirs. An increase in the level of grain refinement means the interdendritic network becomes heavily constricted, resulting in a rapid increase in the feeding pressure required to feed metal to the areas where it is required.

This study has also resulted in the development of a novel method of successfully and consistently introducing carbon to a Mg-Al alloy melt. This has in the past been identified as a major issue to overcome when adding carbon based grain refiners to Mg-Al alloy melts.

text: The Effect of Grain Refinement on the Castability of Magnesium-Aluminium Alloys Rapidly increasing fuel prices and global pressures to reduce the harmful effects of vehicle emissions are forcing vehicle manufacturers to look at alternative materials to reduce the mass of the vehicles they produce. This has led to an increase in the research and development of magnesium alloys for use in automotive applications, and the methods used to produce them. With a density two-thirds that of aluminium alloys, and one quarter that of steel, magnesium alloys are continually being investigated as possible replacements for the production of automotive castings such as wheels and engine blocks. However, there is presently a lack of understanding of the effects of common alloy additions that refine the as-cast microstructure on the castability of the casting alloys in question.

The most popular magnesium alloys for large automotive castings are based on the magnesium-aluminium alloy system. For the work presented in this thesis, two of the most common Mg-Al alloys, AZ91E and AM60B, were chosen to determine the effect of grain refinement on the castability of Mg-Al alloys. An experimental mould has been designed and developed to emulate the geometry, filling, and solidification of an alloy wheel casting. Two different grain refiners were investigated at varying addition levels to determine the effect of different levels of grain refinement on the castability of the two alloys. Castability, defined as the ability to produce sound castings from a particular alloy, has been assessed through visual examination of external casting defects, X-ray radiography of internal defects, as well as grain size and porosity level analysis of all samples produced.

It has been found that for both AZ91E and AM60B, an increase in the level of grain refinement achieved lead to an increase in the occurrence and severity of the surface slumping defect in the castings produced. Conversely, increased levels of grain refinement were found to reduce or totally eliminate the occurrence of the hot tearing defect in both alloys.

Contrary to popular belief, grain refinement was found to increase the level of internal shrinkage porosity in the Mg-Al castings. This was especially the case in the poorly fed regions of the casting, such as the junction between the spoke and rim sections. This is due to the increased reliance on interdendritic feeding of liquid to compensate for shrinkage during the latter stages of solidification in such areas, where solidification does not proceed directionally towards the feeding reservoirs. An increase in the level of grain refinement means the interdendritic network becomes heavily constricted, resulting in a rapid increase in the feeding pressure required to feed metal to the areas where it is required.

This study has also resulted in the development of a novel method of successfully and consistently introducing carbon to a Mg-Al alloy melt. This has in the past been identified as a major issue to overcome when adding carbon based grain refiners to Mg-Al alloy melts.

year: 2007

title: Taku Ara, Taku Mahara: Pākehā Family Experiences of Kaupapa Māori and Bilingual Education

authors: Barnes, Alexander Louis

subjects: Kaupapa Maori

abstract: Kaupapa Māori (indigenous Māori-centred philosophies) initiatives have transformed various social, cultural and public projects in the domains of governance and constitutional issues, health, education, the environment, community development and research in Aotearoa – New Zealand. As a Pākehā graduate of te kōhanga reo and kura kaupapa Māori (Māori language immersion pre-school and primary school), this research is concerned with exploring the impact of kaupapa Māori and bilingual educational initiatives on my life and the lives of two other Pākehā families who share similar educational backgrounds. This foundational study utilises qualitative narrative inquiry methods as a means of understanding and analysing the implications for Pākehā as a result of their participation in kaupapa Māori and bilingual education. An intergenerational family approach is used in this research whereby the individual voices and experiences of young adults are heard equally alongside their parents’. Collectively understood, the themes represented in this research offer a unique means of understanding why Päkehä families decided to be involved in Māori immersion settings, and what these experiences mean to them now. One of the principle aims of this study is that it be used as a platform for dialogue amongst Pākehā, non-Māori and Māori about the future direction of bicultural education in Aotearoa – New Zealand.

text: Taku Ara, Taku Mahara: Pākehā Family Experiences of Kaupapa Māori and Bilingual Education Kaupapa Māori (indigenous Māori-centred philosophies) initiatives have transformed various social, cultural and public projects in the domains of governance and constitutional issues, health, education, the environment, community development and research in Aotearoa – New Zealand. As a Pākehā graduate of te kōhanga reo and kura kaupapa Māori (Māori language immersion pre-school and primary school), this research is concerned with exploring the impact of kaupapa Māori and bilingual educational initiatives on my life and the lives of two other Pākehā families who share similar educational backgrounds. This foundational study utilises qualitative narrative inquiry methods as a means of understanding and analysing the implications for Pākehā as a result of their participation in kaupapa Māori and bilingual education. An intergenerational family approach is used in this research whereby the individual voices and experiences of young adults are heard equally alongside their parents’. Collectively understood, the themes represented in this research offer a unique means of understanding why Päkehä families decided to be involved in Māori immersion settings, and what these experiences mean to them now. One of the principle aims of this study is that it be used as a platform for dialogue amongst Pākehā, non-Māori and Māori about the future direction of bicultural education in Aotearoa – New Zealand.

year: 2006