title: Development and characterisation of low-cost powder metallurgy Ti–Cu–Fe alloys

authors: Bolzoni, Leandro

abstract: The high cost of Ti alloys is still a primary hindering factor for their wider adoption in different engineering sectors in which they would bring significant benefits. This study analysed the simultaneous addition of cheap alloying elements (i.e. Cu and Fe) aiming to quantify the properties of new low-cost ternary TieCueFe alloys obtained via powder metallurgy. It is found that, the amount of alloying elements decreases the compressibility of the powder blends but similar relative density values to those of other powder metallurgy Ti alloys can be achieved. The addition of Cu and Fe leads to the creation of alloys with a lamellar microstructure whose features such as prior b grain size, morphology, interlamellar spacing, and formation of a eutectoid substructure, are determined by the specific chemistry of the alloy. Consequently, the deformation and failure of the sintered ternary TiexCuexFe alloys is governed by the same mechanism but the strength, hard-ness, ductility, and strain hardening rate are alloy dependent.

text: Development and characterisation of low-cost powder metallurgy Ti–Cu–Fe alloys The high cost of Ti alloys is still a primary hindering factor for their wider adoption in different engineering sectors in which they would bring significant benefits. This study analysed the simultaneous addition of cheap alloying elements (i.e. Cu and Fe) aiming to quantify the properties of new low-cost ternary TieCueFe alloys obtained via powder metallurgy. It is found that, the amount of alloying elements decreases the compressibility of the powder blends but similar relative density values to those of other powder metallurgy Ti alloys can be achieved. The addition of Cu and Fe leads to the creation of alloys with a lamellar microstructure whose features such as prior b grain size, morphology, interlamellar spacing, and formation of a eutectoid substructure, are determined by the specific chemistry of the alloy. Consequently, the deformation and failure of the sintered ternary TiexCuexFe alloys is governed by the same mechanism but the strength, hard-ness, ductility, and strain hardening rate are alloy dependent.

year: 2023-05

title: The Weibull distribution as an extreme value model for transformed annual maxima

authors: Bardsley, W. Earl

subjects: Weibull distribution

abstract: There is no mathematical difference between theoretical extreme value models of maxima and minima because they link to each other by a simple sign reversal transformation. However, other transformations that change sample maxima to sample minima raise the possibility of alternatives to the generalised extreme value (GEV) distribution for annual maxima, while still maintaining extreme value justification. A general class of transformation is proposed that converts positive annual maxima to lower-bounded minima, then amenable to Weibull extreme value analysis for sufficiently large sample sizes. That is, the Weibull distribution of smallest extremes provides a theoretical extreme value model for the transformed maxima, which holds irrespective of any GEV form of the original maxima. This would apply, for example, to the analysis of reciprocals of discharge or rainfall annual maxima.
A useful feature of the transformation approach is that alternative prediction expressions with extreme value justification can arise for defining event magnitude as a function of return period. These expressions may result in different hydrological conclusions than from a GEV analysis of maxima. A double exponential transformation is introduced and its prediction function for maxima is noted to have capability to mimic equivalent Type 3 extreme value (EV3) distribution expressions, but without having to introduce an upper bound parameter. The new function gives a good fit to apparent EV3 annual flood maxima recorded from two very different catchments: the Yangtze River in China and the upper Whanganui River in New Zealand.

text: The Weibull distribution as an extreme value model for transformed annual maxima There is no mathematical difference between theoretical extreme value models of maxima and minima because they link to each other by a simple sign reversal transformation. However, other transformations that change sample maxima to sample minima raise the possibility of alternatives to the generalised extreme value (GEV) distribution for annual maxima, while still maintaining extreme value justification. A general class of transformation is proposed that converts positive annual maxima to lower-bounded minima, then amenable to Weibull extreme value analysis for sufficiently large sample sizes. That is, the Weibull distribution of smallest extremes provides a theoretical extreme value model for the transformed maxima, which holds irrespective of any GEV form of the original maxima. This would apply, for example, to the analysis of reciprocals of discharge or rainfall annual maxima.
A useful feature of the transformation approach is that alternative prediction expressions with extreme value justification can arise for defining event magnitude as a function of return period. These expressions may result in different hydrological conclusions than from a GEV analysis of maxima. A double exponential transformation is introduced and its prediction function for maxima is noted to have capability to mimic equivalent Type 3 extreme value (EV3) distribution expressions, but without having to introduce an upper bound parameter. The new function gives a good fit to apparent EV3 annual flood maxima recorded from two very different catchments: the Yangtze River in China and the upper Whanganui River in New Zealand.

year: 2019

title: 'Te Kawau Mārō' The Role of Media in Revitalising Te Reo Māori

authors: Hill, Jessie Lee Anahira

subjects: Media

abstract: The intent of this thesis is to investigate the role media plays in relation to the revitalisation of te reo Māori in Aotearoa/New Zealand society. This is essential as the media's latent potential is often underestimated and therefore underutilised. 

For Māori and inevitably te reo Māori, media has been a topic of heated contestation for over a century. It is postulated that throughout this troubled history, media's influence has contributed to an erosion of te reo Māori and then conversely, since the late 20th century, its attempted revival. The journey of te reo Māori from past to present may be likened to a voyage of a traditional 'waka hourua' (voyaging or double hulled canoe). 'Nga ngaru e toru' ('three waves') illustrates the three stages that I have defined as catalysts significantly impacting te reo Māori. 

Grounded firmly in a Kaupapa Māori methodological and theoretical framework based on careful research and intimate cultural knowledge, my innovative approaches to language revitalisation entitled the Tapatoru (triangle) Model 1 and Tapatoru Model 2 will be introduced and explained. These distinct language revitalisation paradigms illustrate the core ingredients needed in effective language revival and illustrate the positioning and function of the media within these strategic models.

text: 'Te Kawau Mārō' The Role of Media in Revitalising Te Reo Māori The intent of this thesis is to investigate the role media plays in relation to the revitalisation of te reo Māori in Aotearoa/New Zealand society. This is essential as the media's latent potential is often underestimated and therefore underutilised. 

For Māori and inevitably te reo Māori, media has been a topic of heated contestation for over a century. It is postulated that throughout this troubled history, media's influence has contributed to an erosion of te reo Māori and then conversely, since the late 20th century, its attempted revival. The journey of te reo Māori from past to present may be likened to a voyage of a traditional 'waka hourua' (voyaging or double hulled canoe). 'Nga ngaru e toru' ('three waves') illustrates the three stages that I have defined as catalysts significantly impacting te reo Māori. 

Grounded firmly in a Kaupapa Māori methodological and theoretical framework based on careful research and intimate cultural knowledge, my innovative approaches to language revitalisation entitled the Tapatoru (triangle) Model 1 and Tapatoru Model 2 will be introduced and explained. These distinct language revitalisation paradigms illustrate the core ingredients needed in effective language revival and illustrate the positioning and function of the media within these strategic models.

year: 2010