title: Study on hydrogen storage performance of as-milled Ti-V-Cr-Fe-Mn high entropy alloys

authors: Zhai, Yutao

abstract: This study aims to fabricate and optimize BCC-based high-entropy hydrogen storage alloys through mechanical alloying. The research systematically investigates the effects of processing parameters (including milling time, ball-to-powder ratio, rotation speed, and process control agent (PCA) addition), alloy composition, and heat treatment on the phase structure, thermodynamic stability, and hydrogen storage performance of the fabricated alloys. Furthermore, the study compares the microstructure and hydrogen storage properties of alloys fabricated by different methods (mechanical alloying and arc melting).

Firstly, the study optimizes the mechanical alloying parameters, revealing the critical roles of milling time, ball-to-powder ratio, and rotation speed in forming BCC structures and nanocrystalline grains in Ti-V-Cr-Mn-Fe alloys. The regulatory effects of PCA addition on powder yield and particle size are also analyzed. Subsequently, the impact of composition on hydrogen storage properties, including hydrogen absorption/desorption kinetics, thermodynamic behavior, and cycling stability, are explored by varying the Ti content and Mn/Cr ratios. It is found that increasing Ti content enhances the proportion of C14 Laves phases, while increasing Mn content effectively suppresses Laves phase formation, thereby increasing the BCC phase fraction and improving hydrogen storage kinetics.

Additionally, the role of heat treatment is examined. Microstructural evolution analysis reveals the phase transformation behavior among BCC, FCC, and Laves phases under different heat treatment conditions and their effects on hydrogen storage capacity. Specifically, as the temperature increases, the BCC structure first decomposes into a BCC + FCC dual-phase structure, followed by the precipitation of the Laves-2 phase within the FCC phase. After high-temperature treatment, the lattice constant of the BCC phase decreases, and the synergistic effect of the Laves and FCC phases results in a slight reduction in the hydrogen absorption and desorption capacity of the alloy. Finally, by comparing different fabricating process, the differences in microstructure and hydrogen storage performance of Ti25V35(CrMnFe)40 alloys prepared by these methods are investigated. The results suggested that Mechanical alloying significantly enhances initial the activation performance and hydrogen absorption kinetics of the as-milled alloys are improved compared to the counterparts of as-cast alloys.

text: Study on hydrogen storage performance of as-milled Ti-V-Cr-Fe-Mn high entropy alloys This study aims to fabricate and optimize BCC-based high-entropy hydrogen storage alloys through mechanical alloying. The research systematically investigates the effects of processing parameters (including milling time, ball-to-powder ratio, rotation speed, and process control agent (PCA) addition), alloy composition, and heat treatment on the phase structure, thermodynamic stability, and hydrogen storage performance of the fabricated alloys. Furthermore, the study compares the microstructure and hydrogen storage properties of alloys fabricated by different methods (mechanical alloying and arc melting).

Firstly, the study optimizes the mechanical alloying parameters, revealing the critical roles of milling time, ball-to-powder ratio, and rotation speed in forming BCC structures and nanocrystalline grains in Ti-V-Cr-Mn-Fe alloys. The regulatory effects of PCA addition on powder yield and particle size are also analyzed. Subsequently, the impact of composition on hydrogen storage properties, including hydrogen absorption/desorption kinetics, thermodynamic behavior, and cycling stability, are explored by varying the Ti content and Mn/Cr ratios. It is found that increasing Ti content enhances the proportion of C14 Laves phases, while increasing Mn content effectively suppresses Laves phase formation, thereby increasing the BCC phase fraction and improving hydrogen storage kinetics.

Additionally, the role of heat treatment is examined. Microstructural evolution analysis reveals the phase transformation behavior among BCC, FCC, and Laves phases under different heat treatment conditions and their effects on hydrogen storage capacity. Specifically, as the temperature increases, the BCC structure first decomposes into a BCC + FCC dual-phase structure, followed by the precipitation of the Laves-2 phase within the FCC phase. After high-temperature treatment, the lattice constant of the BCC phase decreases, and the synergistic effect of the Laves and FCC phases results in a slight reduction in the hydrogen absorption and desorption capacity of the alloy. Finally, by comparing different fabricating process, the differences in microstructure and hydrogen storage performance of Ti25V35(CrMnFe)40 alloys prepared by these methods are investigated. The results suggested that Mechanical alloying significantly enhances initial the activation performance and hydrogen absorption kinetics of the as-milled alloys are improved compared to the counterparts of as-cast alloys.

year: 2025-07-16

title: Government Involvement in New Zealand Sport - Sport Policy: a Cautionary Tale

authors: Lawrence, Hugh David Vincent

subjects: Sport policy

abstract: Government involvement in New Zealand sport spans over 70 years from provisions of the Physical Welfare Act in 1937 to current provisions of the Sport and Recreation Act 2002. Thousands of volunteers in non-profit organisations continue to underpin New Zealand's sport system. It is axiomatic that sport defines part of what it means to be a New Zealander. Governments frequently use the rhetoric of community cohesion, national pride, life skills and public health benefits to justify its involvement. This thesis examines the impact of government intervention on the sport sector, its funding paradigms and the extent of sector engagement in a policy for sport.
Through an examination of available government and sport sector records, and the author's own experience as a participant in events, the thesis recounts a sequence of five milestones for the New Zealand sport system and views them through a public management system lens. The passing of the Physical Welfare and Recreation Act in 1937, the establishment of a Ministry and Council for Recreation and Sport in 1973, the ministerial Sports Development Inquiry in 1984, the Prime Minister's Review of High Performance Sport in 1995 and the Sport, Fitness and Leisure Ministerial Taskforce. Government funding of sport now stands at around $100 million annually from small beginnings of $3,295 in 1945/1946, despite the absence of a comprehensive national policy for sport.
By examining the chronology through a wider state sector lens, the thesis opens a window to the practical effect of public policy processes on matters of importance to the New Zealand sport sector and its voluntary sector foundations.
This thesis also provides a rationale for revitalising the engagement between government and the New Zealand sport sector to meet the expectations of a modern state sector to meaningfully engage citizens and the non-government sector in the formation of policy and planning its implementation.

text: Government Involvement in New Zealand Sport - Sport Policy: a Cautionary Tale Government involvement in New Zealand sport spans over 70 years from provisions of the Physical Welfare Act in 1937 to current provisions of the Sport and Recreation Act 2002. Thousands of volunteers in non-profit organisations continue to underpin New Zealand's sport system. It is axiomatic that sport defines part of what it means to be a New Zealander. Governments frequently use the rhetoric of community cohesion, national pride, life skills and public health benefits to justify its involvement. This thesis examines the impact of government intervention on the sport sector, its funding paradigms and the extent of sector engagement in a policy for sport.
Through an examination of available government and sport sector records, and the author's own experience as a participant in events, the thesis recounts a sequence of five milestones for the New Zealand sport system and views them through a public management system lens. The passing of the Physical Welfare and Recreation Act in 1937, the establishment of a Ministry and Council for Recreation and Sport in 1973, the ministerial Sports Development Inquiry in 1984, the Prime Minister's Review of High Performance Sport in 1995 and the Sport, Fitness and Leisure Ministerial Taskforce. Government funding of sport now stands at around $100 million annually from small beginnings of $3,295 in 1945/1946, despite the absence of a comprehensive national policy for sport.
By examining the chronology through a wider state sector lens, the thesis opens a window to the practical effect of public policy processes on matters of importance to the New Zealand sport sector and its voluntary sector foundations.
This thesis also provides a rationale for revitalising the engagement between government and the New Zealand sport sector to meet the expectations of a modern state sector to meaningfully engage citizens and the non-government sector in the formation of policy and planning its implementation.

year: 2008

title: When Two Worlds Collide: Mātauranga Māori, Science and Health of the Toreparu Wetland

authors: Robb, Mahuru Joyce Gordon

subjects: Mātauranga Māori

abstract: Much of our understanding of wetland health and function comes from scientific-based monitoring and methodologies. However, there is a wealth of knowledge to be gained from Māori-value based assessment methods for monitoring wetlands in New Zealand. I used the Wetland Cultural Health Index (WCHI) and a variety of scientific wetland survey methods to examine how these two approaches complement each other. For this research, I worked with the people from Mōtakotako marae at the Toreparu wetland (Waikato), developing a set of site specific cultural indicators. 
Comparative analysis revealed a range of similarities and differences between the WCHI indices and scientific parameters. We found that as Wetland Cultural Health Measure (WCHM) scores increased, there was also an increase in dissolved oxygen concentration, SQMCI-sb values, and total nitrogen concentrations. Cultural indices provided an overall indication of site health. It was apparent, however, that scores of contributing indicators could vary markedly at any one site. As such, high scores for some indicators (e.g., vegetation values) may obscure low values for other variables (e.g., water quality), providing an index that depicts site health as being of average condition. 
Capacity and resourcing issues were also highlighted as being an issue for Māori to be able to successfully carry out wetland monitoring, but also for staff in councils and other research and environmental governing bodies to build and maintain relationships with tangata whenua. Other challenges around site access provided a unique opportunity to develop and trial new WCHI assessment techniques. The use of video assessment to carry out WCHI monitoring was of varying success. Indicators that could be scored by visual assessment were useful, but indicators that relied on sound or felt sensation were difficult to assess. The use of mauri (life force) as an indicator had benefits when applied to the whole catchment, but the volunteer participants challenged its validity when used at the smaller site scale. Volunteers found assigning a numerical value to mauri very difficult, and felt that reducing mauri to a single number may diminish the significance of this holistic and metaphysical concept.  Mauri has been used successfully as a measure of environmental health but it is important to communicate and understand what mauri is and why it is measured.
Overall, the WCHI provided a wealth of information that could not be captured through scientific sampling, such as the presence of dye source, loss of bird/fish species and baseline information on the past condition of the Toreparu before the surrounding land was converted for agricultural use. This confirms that our understanding of wetland health is enhanced through the inclusion of cultural values.
As the New Zealand government and Māori move towards a future of collaborative research and management of freshwater ecosystems, there is a need for greater understanding around cultural values and priorities. By using both scientific and Māori-value based wetland monitoring methods, Māori can articulate a range of values, goals and priorities to help inform environmental decision makers and empower iwi and hapū to have a meaningful and sustainable role in the management of wetlands.  There needs to be a foundation of mutual understanding and relationships built between environmental governing bodies and Māori for the future success of collaborative research and management of New Zealand's wetlands.

text: When Two Worlds Collide: Mātauranga Māori, Science and Health of the Toreparu Wetland Much of our understanding of wetland health and function comes from scientific-based monitoring and methodologies. However, there is a wealth of knowledge to be gained from Māori-value based assessment methods for monitoring wetlands in New Zealand. I used the Wetland Cultural Health Index (WCHI) and a variety of scientific wetland survey methods to examine how these two approaches complement each other. For this research, I worked with the people from Mōtakotako marae at the Toreparu wetland (Waikato), developing a set of site specific cultural indicators. 
Comparative analysis revealed a range of similarities and differences between the WCHI indices and scientific parameters. We found that as Wetland Cultural Health Measure (WCHM) scores increased, there was also an increase in dissolved oxygen concentration, SQMCI-sb values, and total nitrogen concentrations. Cultural indices provided an overall indication of site health. It was apparent, however, that scores of contributing indicators could vary markedly at any one site. As such, high scores for some indicators (e.g., vegetation values) may obscure low values for other variables (e.g., water quality), providing an index that depicts site health as being of average condition. 
Capacity and resourcing issues were also highlighted as being an issue for Māori to be able to successfully carry out wetland monitoring, but also for staff in councils and other research and environmental governing bodies to build and maintain relationships with tangata whenua. Other challenges around site access provided a unique opportunity to develop and trial new WCHI assessment techniques. The use of video assessment to carry out WCHI monitoring was of varying success. Indicators that could be scored by visual assessment were useful, but indicators that relied on sound or felt sensation were difficult to assess. The use of mauri (life force) as an indicator had benefits when applied to the whole catchment, but the volunteer participants challenged its validity when used at the smaller site scale. Volunteers found assigning a numerical value to mauri very difficult, and felt that reducing mauri to a single number may diminish the significance of this holistic and metaphysical concept.  Mauri has been used successfully as a measure of environmental health but it is important to communicate and understand what mauri is and why it is measured.
Overall, the WCHI provided a wealth of information that could not be captured through scientific sampling, such as the presence of dye source, loss of bird/fish species and baseline information on the past condition of the Toreparu before the surrounding land was converted for agricultural use. This confirms that our understanding of wetland health is enhanced through the inclusion of cultural values.
As the New Zealand government and Māori move towards a future of collaborative research and management of freshwater ecosystems, there is a need for greater understanding around cultural values and priorities. By using both scientific and Māori-value based wetland monitoring methods, Māori can articulate a range of values, goals and priorities to help inform environmental decision makers and empower iwi and hapū to have a meaningful and sustainable role in the management of wetlands.  There needs to be a foundation of mutual understanding and relationships built between environmental governing bodies and Māori for the future success of collaborative research and management of New Zealand's wetlands.

year: 2014