title: Fabrication of TiAl target by mechanical alloying and applications in physical vapour deposition coating

authors: Gabbitas, Brian

subjects: mechanical alloying

abstract: The research involves the development of a powder metallurgical route for producing good quality TiAl targets for making physical vapour deposition (PVD) coatings. Mixtures of elemental titanium and aluminium powders were mechanically milled using a novel discus milling technique under various conditions. Hot isostatic pressing (HIP) was then employed for consolidation of the mechanically alloyed powders. A cathodic arc vapour deposition process was applied to produce a TiAIN coating. A microstructural examination was conducted on the target material and PVD coatings, using X-ray diffractometry (XRD), X-ray photoelectron spectrometry (XPS) and scanning electron microscopy (SEM). It has been found that combining mechanical alloying and HIP enable us to produce a fairly good quality of TiAl based target. The PVD coatings obtained from the TiAl target showed very high microhardness values.

text: Fabrication of TiAl target by mechanical alloying and applications in physical vapour deposition coating The research involves the development of a powder metallurgical route for producing good quality TiAl targets for making physical vapour deposition (PVD) coatings. Mixtures of elemental titanium and aluminium powders were mechanically milled using a novel discus milling technique under various conditions. Hot isostatic pressing (HIP) was then employed for consolidation of the mechanically alloyed powders. A cathodic arc vapour deposition process was applied to produce a TiAIN coating. A microstructural examination was conducted on the target material and PVD coatings, using X-ray diffractometry (XRD), X-ray photoelectron spectrometry (XPS) and scanning electron microscopy (SEM). It has been found that combining mechanical alloying and HIP enable us to produce a fairly good quality of TiAl based target. The PVD coatings obtained from the TiAl target showed very high microhardness values.

year: 2007

title: Reference and current Trophic Level Index of New Zealand lakes: benchmarks to inform lake management and assessment

authors: Abell, Jonathan Michael

subjects: Science & technology

abstract: Knowledge of trophic status is fundamental to understanding the condition and function of lake ecosystems. We developed regression models to predict chlorophyll a concentrations (chl a) in New Zealand lakes for reference and current states, based on an existing dataset of total nitrogen (TN) and total phosphorus (TP) concentrations for 1031 lakes. Models were then developed to predict Secchi depth based on chl a and a sediment resuspension term applicable to shallow lakes. Estimates of all four Trophic Level Index (TLI) variables (chl a, TN, TP and Secchi depth) were analysed to estimate reference and current state TLI for the nationally representative sample of 1031 lakes. There was a trend of eutrophication between reference and current states, with systematic differences among lake geomorphic types. Mean chl a increased 3.5-fold (2.42 mg m­¯­­­³ vs. 8.32 mg m¯³) and mean Secchi depth decreased (indicating lower clarity) by approximately one-third (9.62 m vs. 6.48 m) between reference and current states. On average, TLI increased by 0.67, with the TLI increase >1 in approximately one-third (31%) of lakes. This study informs the status of lake ecosystems in NZ and provides benchmarks to guide management and assessment.

text: Reference and current Trophic Level Index of New Zealand lakes: benchmarks to inform lake management and assessment Knowledge of trophic status is fundamental to understanding the condition and function of lake ecosystems. We developed regression models to predict chlorophyll a concentrations (chl a) in New Zealand lakes for reference and current states, based on an existing dataset of total nitrogen (TN) and total phosphorus (TP) concentrations for 1031 lakes. Models were then developed to predict Secchi depth based on chl a and a sediment resuspension term applicable to shallow lakes. Estimates of all four Trophic Level Index (TLI) variables (chl a, TN, TP and Secchi depth) were analysed to estimate reference and current state TLI for the nationally representative sample of 1031 lakes. There was a trend of eutrophication between reference and current states, with systematic differences among lake geomorphic types. Mean chl a increased 3.5-fold (2.42 mg m­¯­­­³ vs. 8.32 mg m¯³) and mean Secchi depth decreased (indicating lower clarity) by approximately one-third (9.62 m vs. 6.48 m) between reference and current states. On average, TLI increased by 0.67, with the TLI increase >1 in approximately one-third (31%) of lakes. This study informs the status of lake ecosystems in NZ and provides benchmarks to guide management and assessment.

year: 2020

title: Claiming spaces: Prioritising Maaori worldview

authors: Penehira, Mera

subjects: Maori

abstract: Ohomairangi Trust was established as a provider of early intervention services in February 2002. It is funded and accredited by the Ministry of Education, and is the first Kaupapa Maaori based early intervention service to be accredited by the Ministry of Education. Essentially Ohomairangi was developed because of a need in the community for a service that could focus on developing and providing early intervention in a uniquely Maaori way, without the constraints of a crown agency. The Ohomairangi early intervention team has a commitment to supporting both the positive developments for Maaori within the Ministry of Education, and the continued independent research and development of Kaupapa Maaori services. The primary purpose of Ohomairangi is to develop and provide a Kaupapa Maaori based early intervention service across Taamaki Makaurau, which meets recommended practice guidelines. This evolves from a starting point of Kaupapa Maaori theory.

text: Claiming spaces: Prioritising Maaori worldview Ohomairangi Trust was established as a provider of early intervention services in February 2002. It is funded and accredited by the Ministry of Education, and is the first Kaupapa Maaori based early intervention service to be accredited by the Ministry of Education. Essentially Ohomairangi was developed because of a need in the community for a service that could focus on developing and providing early intervention in a uniquely Maaori way, without the constraints of a crown agency. The Ohomairangi early intervention team has a commitment to supporting both the positive developments for Maaori within the Ministry of Education, and the continued independent research and development of Kaupapa Maaori services. The primary purpose of Ohomairangi is to develop and provide a Kaupapa Maaori based early intervention service across Taamaki Makaurau, which meets recommended practice guidelines. This evolves from a starting point of Kaupapa Maaori theory.

year: 2008