title: Behavior of Different β Stabilizers on the Microstructure and Properties of Ternary Ti‐3Sn‐X Alloys

authors: Bolzoni, Leandro

abstract: The manufacturing of Ti alloys via powder metallurgy and the development of novel compositions are two strategies to reduce the cost of Ti, which is still the primary factor deterring its wider use in engineering applications. In this study, new Ti alloys based on the combined addition of Sn with Nb, Mo, or Mn are manufactured via powder metallurgy to gain an understanding of the role of these β stabilizers on the performance achievable. It is found that the designed alloys have a fully homogeneous chemistry regardless of their actual composition and a lamellar or β‐type microstructure depending on the actual β stabilizer used. This study confirms that the β‐stabilizing power effect decreases from Mn to Mo and, eventually, Nb. The compressibility and sinterability of the alloys increase with the progressive addition of the selected powders, generally leading to stronger and more ductile materials. It is also found that the proposed Ti‐3Sn‐Mo alloys are characterized by the best strength/ductility pairs compared to a variety of sintered or cast binary/ternary Ti alloys bearing the alloying elements considered in this work.

text: Behavior of Different β Stabilizers on the Microstructure and Properties of Ternary Ti‐3Sn‐X Alloys The manufacturing of Ti alloys via powder metallurgy and the development of novel compositions are two strategies to reduce the cost of Ti, which is still the primary factor deterring its wider use in engineering applications. In this study, new Ti alloys based on the combined addition of Sn with Nb, Mo, or Mn are manufactured via powder metallurgy to gain an understanding of the role of these β stabilizers on the performance achievable. It is found that the designed alloys have a fully homogeneous chemistry regardless of their actual composition and a lamellar or β‐type microstructure depending on the actual β stabilizer used. This study confirms that the β‐stabilizing power effect decreases from Mn to Mo and, eventually, Nb. The compressibility and sinterability of the alloys increase with the progressive addition of the selected powders, generally leading to stronger and more ductile materials. It is also found that the proposed Ti‐3Sn‐Mo alloys are characterized by the best strength/ductility pairs compared to a variety of sintered or cast binary/ternary Ti alloys bearing the alloying elements considered in this work.

year: 2023

title: Rangitoto volcano excursion, Auckland. Pre-conference field trip

authors: Lowe, David J.

abstract: Rangitoto is one of Auckland City’s more iconic landscape features. Guarding the entrance to the Waitemata Harbour, Rangitoto is a symmetrical, ~6-km wide, basaltic shield volcano that last erupted ~550 years ago shortly after the arrival and settlement of Polynesians in the Auckland region (c. 1280 AD). Rangitoto is by far the largest, and also the youngest, volcano in the Auckland Volcanic Field (AVF). The AVF is a monogenetic volcanic field consisting of approximately 53 individual eruptive centres, all of which are within the boundaries of the Auckland urban area. Recent research has revealed more about Rangitoto’s eruptive history, which may date back to c. 1500 years ago (Shane et al. 2013). Some of these findings have been noted below and will be discussed further while we ascend its summit and explore its various landscape and vegetational features.

text: Rangitoto volcano excursion, Auckland. Pre-conference field trip Rangitoto is one of Auckland City’s more iconic landscape features. Guarding the entrance to the Waitemata Harbour, Rangitoto is a symmetrical, ~6-km wide, basaltic shield volcano that last erupted ~550 years ago shortly after the arrival and settlement of Polynesians in the Auckland region (c. 1280 AD). Rangitoto is by far the largest, and also the youngest, volcano in the Auckland Volcanic Field (AVF). The AVF is a monogenetic volcanic field consisting of approximately 53 individual eruptive centres, all of which are within the boundaries of the Auckland urban area. Recent research has revealed more about Rangitoto’s eruptive history, which may date back to c. 1500 years ago (Shane et al. 2013). Some of these findings have been noted below and will be discussed further while we ascend its summit and explore its various landscape and vegetational features.

year: 2014-08-30

title: The Application of Critical Discourse Theory: A Criterion-Referenced Analysis of Reports Relating to Language Revitalisation in Australia and New Zealand

authors: Lewis, Roger Brian

subjects: te reo Māori

abstract: The discipline of language policy and planning (LPP) is often proposed as a viable tool for language revitalisation. However, the conventional paradigm upon which LPP is based is inadequate for such an inherently political, contentious and problematic area of social policy, and does not address the hegemonic and counter-hegemonic discourse that is at the very core of language revitalisation efforts. It is therefore argued here that LPP needs to be explicitly underpinned by critical discourse theory (CDT) if it is to be of genuine use to those involved in language revitalisation efforts, particularly to grass roots language activists. Following an introductory chapter which provides a background to the research and a rationale for it (Chapter 1), there is a critical review of selected literature on LPP and CDT, a review which ends by proposing a list of criteria which, it is argued, can be used to determine the extent to which discourse that is intended to be counter-hegemonic adheres to the principles of effective counter-hegemonic discourse as outlined in the literature on CDT (Chapter 2). In the following three chapters (Chapters 3, 4 & 5), these criteria are applied to the analysis of three recent reports that have a direct bearing on indigenous language revitalisation in Australia (Our Land Our Languages) and New Zealand (Ko Aotearoa Tēnei and Te Reo Mauriora). The first of these reports is found to adhere very closely to the criteria; the second less so; the third almost not at all. The different ways in which each of these reports has been received would tend to support the hypothesis that, other things being equal, the more closely a text of this type conforms to the criteria - that is, the more closely it is aligned to the fundamental principles of effective counter-hegemonic discourse as outlined in CDT - the more likely it is to be positively received and, therefore, to represent an effective challenge to the existing hegemony. The overall conclusion is that CDT can not only assist language activists by providing a basis for determining how successful counter-hegemonic discourse is likely to be in achieving its aims but has the potential to provide LPP with a secure theoretical foundation (Chapter 6).

text: The Application of Critical Discourse Theory: A Criterion-Referenced Analysis of Reports Relating to Language Revitalisation in Australia and New Zealand The discipline of language policy and planning (LPP) is often proposed as a viable tool for language revitalisation. However, the conventional paradigm upon which LPP is based is inadequate for such an inherently political, contentious and problematic area of social policy, and does not address the hegemonic and counter-hegemonic discourse that is at the very core of language revitalisation efforts. It is therefore argued here that LPP needs to be explicitly underpinned by critical discourse theory (CDT) if it is to be of genuine use to those involved in language revitalisation efforts, particularly to grass roots language activists. Following an introductory chapter which provides a background to the research and a rationale for it (Chapter 1), there is a critical review of selected literature on LPP and CDT, a review which ends by proposing a list of criteria which, it is argued, can be used to determine the extent to which discourse that is intended to be counter-hegemonic adheres to the principles of effective counter-hegemonic discourse as outlined in the literature on CDT (Chapter 2). In the following three chapters (Chapters 3, 4 & 5), these criteria are applied to the analysis of three recent reports that have a direct bearing on indigenous language revitalisation in Australia (Our Land Our Languages) and New Zealand (Ko Aotearoa Tēnei and Te Reo Mauriora). The first of these reports is found to adhere very closely to the criteria; the second less so; the third almost not at all. The different ways in which each of these reports has been received would tend to support the hypothesis that, other things being equal, the more closely a text of this type conforms to the criteria - that is, the more closely it is aligned to the fundamental principles of effective counter-hegemonic discourse as outlined in CDT - the more likely it is to be positively received and, therefore, to represent an effective challenge to the existing hegemony. The overall conclusion is that CDT can not only assist language activists by providing a basis for determining how successful counter-hegemonic discourse is likely to be in achieving its aims but has the potential to provide LPP with a secure theoretical foundation (Chapter 6).

year: 2014