title: An experimental study of the state of equilibrium in an inductively-coupled plasma torch

authors: Miller, George Paul

abstract: An experimental study of the state of equilibrium existing in an atmospheric pressure argon inductively-coupled plasma torch (ICPT) has been undertaken using several diagnostic methods. In particular, a relaxation technique was used which involved pulsing off the RF field rapidly (< 3 μs) and monitoring the subsequent intensity changes in the optically-thin excited argon I spectral lines. The removal of the RF field is accompanied by a sharp intensity increase persisting for about 18μs before falling monotonically. This effect is explained in terms of the theory of collision-radiation decay of a plasma.
The increase in spectral line intensity is used to ascertain whether the optically-thin excited Ar I states conform to a Boltzmann distribution for various operating conditions of the ICPT. For those cases where the excited states are close to a Boltzmann distribution, this method is used to determine the difference in temperature between the electrons (Tₑ) and the heavy particles (Tg) as well as the electron temperature. In addition, the same technique applied to a near saturated (optically thick) Ar I spectral line (811.5nm) is used to observe changes in radiative losses from the plasma. 
The results obtained show that a single flow (coolant only) ICPT plasma is in a state of pLTE in the central regions (r < 7mm). Not only do the optically-thin excited Ar I states conform to a Boltzmann distribution but centrally Tₑ = Tg to closer than 3% and Tₑ ≈ 10,000 K. 
The introduction of a second (aerosol) flow axially through the plasma is shown to cause a deviation from excitational equilibrium across the entire plasma radius. Increasing this flow from 1 1/min to 2 1/min appeared to return the plasma to a state of excitational equilibrium, but the temperatures obtained became inconsistent with the validity of Saha’s equation, i.e. indicating a non-Boltzmann distribution of the Ar I states. The radiative losses are increased significantly. The introduction of certain aerosols viz, 4%H₂ 4%Air, H₂O and KC1, into the plasma are shown to have negligible effect on the state of equilibrium. 
Four different methods used to obtain the electron density, (Stark broadening, interferometry, absolute intensity of the continuum, and Saha’s equation calculations) were compared for various cases. With a single flow plasma the results were consistent, and are typically in the range 10²¹ - 10²² m⁻³. With the introduction of the second flow, the method based on Saha’s equation yields results inconsistent with the other methods, confirming the significant deviation from equilibrium for this system. 
Calculations show that the deviation from excitational equilibrium is consistent with convective losses resulting from the forced flow of argon through the torch.

text: An experimental study of the state of equilibrium in an inductively-coupled plasma torch An experimental study of the state of equilibrium existing in an atmospheric pressure argon inductively-coupled plasma torch (ICPT) has been undertaken using several diagnostic methods. In particular, a relaxation technique was used which involved pulsing off the RF field rapidly (< 3 μs) and monitoring the subsequent intensity changes in the optically-thin excited argon I spectral lines. The removal of the RF field is accompanied by a sharp intensity increase persisting for about 18μs before falling monotonically. This effect is explained in terms of the theory of collision-radiation decay of a plasma.
The increase in spectral line intensity is used to ascertain whether the optically-thin excited Ar I states conform to a Boltzmann distribution for various operating conditions of the ICPT. For those cases where the excited states are close to a Boltzmann distribution, this method is used to determine the difference in temperature between the electrons (Tₑ) and the heavy particles (Tg) as well as the electron temperature. In addition, the same technique applied to a near saturated (optically thick) Ar I spectral line (811.5nm) is used to observe changes in radiative losses from the plasma. 
The results obtained show that a single flow (coolant only) ICPT plasma is in a state of pLTE in the central regions (r < 7mm). Not only do the optically-thin excited Ar I states conform to a Boltzmann distribution but centrally Tₑ = Tg to closer than 3% and Tₑ ≈ 10,000 K. 
The introduction of a second (aerosol) flow axially through the plasma is shown to cause a deviation from excitational equilibrium across the entire plasma radius. Increasing this flow from 1 1/min to 2 1/min appeared to return the plasma to a state of excitational equilibrium, but the temperatures obtained became inconsistent with the validity of Saha’s equation, i.e. indicating a non-Boltzmann distribution of the Ar I states. The radiative losses are increased significantly. The introduction of certain aerosols viz, 4%H₂ 4%Air, H₂O and KC1, into the plasma are shown to have negligible effect on the state of equilibrium. 
Four different methods used to obtain the electron density, (Stark broadening, interferometry, absolute intensity of the continuum, and Saha’s equation calculations) were compared for various cases. With a single flow plasma the results were consistent, and are typically in the range 10²¹ - 10²² m⁻³. With the introduction of the second flow, the method based on Saha’s equation yields results inconsistent with the other methods, confirming the significant deviation from equilibrium for this system. 
Calculations show that the deviation from excitational equilibrium is consistent with convective losses resulting from the forced flow of argon through the torch.

year: 1987

title: Spiritual beliefs, practices, and shadows of the Ahmadiyya Jama’at in Fiji

authors: Berndorff, Valentýna

abstract: This doctoral thesis examines the self-perceptions and lived experiences of Fijian Ahmadis - members of a transnational religious minority who self-identify as Muslims under the spiritual leadership of the Khalifa based in London, UK. The global Ahmadiyya Jama’at positions its adherents as divinely appointed bearers of the truest form of Islam, uniquely entrusted with leading others “from darkness to light”. 
At its core, this thesis poses a central question: how do Fijian Ahmadis pursue and sustain their religious identity and practices in a remote Pacific context, within a pluralistic yet predominantly Christian society? Drawing on six months of ethnographic fieldwork in Fiji, complemented by additional research among Ahmadis in New Zealand, this study explores how Fijian Ahmadis conform to doctrinal orthodoxy, navigate communal authority, articulate theological claims and interact both internally and with other Fijians. In this thesis, I critically examine the tensions Fijian Ahmadis face in balancing their local religious life with the global aspirations of the Ahmadiyya Jama’at - addressing certain contradictions while allowing others to remain obscured in the shadows of rigorous daily practice. A strong sense of communal exclusivity is shown to be sustained through the movement’s bureaucratic apparatus, which promotes submission to its centralised hierarchy, religious discipline, and personal sacrifice. I contend that by prioritising religious identity and communal purity, this framework reorients Fijian Ahmadis away from their immediate social environment towards alignment with the global Ahmadiyya Jama’at, thereby limiting their deeper engagement with broader Fijian society. Further, this thesis addresses gendered expressions of religiosity and modesty, illustrating how the practice of purdah among Fijian Ahmadis both embodies and reinforces traditional gender roles. Finally, while the community publicly promotes values of tolerance and humanism, these ideals often remain bounded by religious and moral distinctiveness. The tension between rhetorical inclusivity and lived exclusivity becomes especially evident in the Ahmadiyya leadership’s controversial response to the ongoing conflict and genocide in Gaza.

text: Spiritual beliefs, practices, and shadows of the Ahmadiyya Jama’at in Fiji This doctoral thesis examines the self-perceptions and lived experiences of Fijian Ahmadis - members of a transnational religious minority who self-identify as Muslims under the spiritual leadership of the Khalifa based in London, UK. The global Ahmadiyya Jama’at positions its adherents as divinely appointed bearers of the truest form of Islam, uniquely entrusted with leading others “from darkness to light”. 
At its core, this thesis poses a central question: how do Fijian Ahmadis pursue and sustain their religious identity and practices in a remote Pacific context, within a pluralistic yet predominantly Christian society? Drawing on six months of ethnographic fieldwork in Fiji, complemented by additional research among Ahmadis in New Zealand, this study explores how Fijian Ahmadis conform to doctrinal orthodoxy, navigate communal authority, articulate theological claims and interact both internally and with other Fijians. In this thesis, I critically examine the tensions Fijian Ahmadis face in balancing their local religious life with the global aspirations of the Ahmadiyya Jama’at - addressing certain contradictions while allowing others to remain obscured in the shadows of rigorous daily practice. A strong sense of communal exclusivity is shown to be sustained through the movement’s bureaucratic apparatus, which promotes submission to its centralised hierarchy, religious discipline, and personal sacrifice. I contend that by prioritising religious identity and communal purity, this framework reorients Fijian Ahmadis away from their immediate social environment towards alignment with the global Ahmadiyya Jama’at, thereby limiting their deeper engagement with broader Fijian society. Further, this thesis addresses gendered expressions of religiosity and modesty, illustrating how the practice of purdah among Fijian Ahmadis both embodies and reinforces traditional gender roles. Finally, while the community publicly promotes values of tolerance and humanism, these ideals often remain bounded by religious and moral distinctiveness. The tension between rhetorical inclusivity and lived exclusivity becomes especially evident in the Ahmadiyya leadership’s controversial response to the ongoing conflict and genocide in Gaza.

year: 2026-01

title: Whāingaroa/Raglan and positive youth development - Community-driven youth support in Whāingaroa: A case study of the Whāingaroa Youth Work Collective

authors: Semeraro, Gianluca

abstract: This research explores the development and impact of community-driven youth support in Whāingaroa, a rural community in Aotearoa/New Zealand, through an in-depth examination of a local youth work collective. By employing a qualitative, participatory research methodology, the study investigates the complex dynamics of youth empowerment, community engagement, and cultural responsiveness within a unique local context.

The study traces the evolution of the Whāingaroa Youth Work Collective (WYWC) from its inception to its status as a structured community organization. Data collection spanned two years, encompassing six WYWC collective meetings and three focus groups with key collective members. Through ethnographic observations and collaborative research methods, the study illuminates the processes of youth development and community support emerging from grassroots, volunteer-driven initiatives. Thematic analysis was employed to analyse the data, which was categorized into two primary themes: (1) the collective's purpose and operational methodology, and (2) necessary future steps to address gaps in local youth support. These themes were analysed in relation to two research questions:

•	How can Whāingaroa/Raglan services support youth at a community-based level?
•	What initiatives could be implemented to foster positive youth development in the future?

The findings are presented in two main sections. The first examines the collective's strategy, operational framework and current initiatives demonstrating the effectiveness of locally-based youth support. The second explores the collective's aspirations for future initiatives, specifically focusing on two key proposals: establishing a full-time youth connector position and developing a community youth hub.

 Key findings demonstrate the transformative potential of volunteer-driven, culturally responsive youth support strategies. The research highlights the importance of contextual understanding, community ownership, and holistic approaches to youth development. Particularly significant is the model's ability to navigate the bicultural landscape of Aotearoa, providing a nuanced approach that respects both indigenous and contemporary cultural frameworks.

Theoretically grounded in Positive Youth Development (PYD) frameworks and indigenous cultural perspectives, the research bridges Western psychological approaches with local cultural understanding. The study reveals how a community-centric model of youth support can effectively address the complex needs of rural youth, emphasizing cultural identity, collective empowerment, and local knowledge.

The study contributes to broader discussions on youth support, community development, and cultural resilience. It challenges traditional, standardized intervention models by showcasing the effectiveness of locally embedded, flexible support strategies. The research provides valuable insights for community organizations, policymakers, educational institutions, and social service providers seeking innovative approaches to youth engagement.
Further, the findings offer a replicable framework for understanding and supporting youth development in rural contexts, with broader implications for community support strategies that prioritize local knowledge, cultural responsiveness, and collective empowerment.

Ultimately, the research presents a compelling argument for understanding youth development as a collaborative, contextually embedded process. It demonstrates that meaningful community support emerges from within, driven by local aspirations, cultural understanding, and collective investment in young people's potential.

text: Whāingaroa/Raglan and positive youth development - Community-driven youth support in Whāingaroa: A case study of the Whāingaroa Youth Work Collective This research explores the development and impact of community-driven youth support in Whāingaroa, a rural community in Aotearoa/New Zealand, through an in-depth examination of a local youth work collective. By employing a qualitative, participatory research methodology, the study investigates the complex dynamics of youth empowerment, community engagement, and cultural responsiveness within a unique local context.

The study traces the evolution of the Whāingaroa Youth Work Collective (WYWC) from its inception to its status as a structured community organization. Data collection spanned two years, encompassing six WYWC collective meetings and three focus groups with key collective members. Through ethnographic observations and collaborative research methods, the study illuminates the processes of youth development and community support emerging from grassroots, volunteer-driven initiatives. Thematic analysis was employed to analyse the data, which was categorized into two primary themes: (1) the collective's purpose and operational methodology, and (2) necessary future steps to address gaps in local youth support. These themes were analysed in relation to two research questions:

•	How can Whāingaroa/Raglan services support youth at a community-based level?
•	What initiatives could be implemented to foster positive youth development in the future?

The findings are presented in two main sections. The first examines the collective's strategy, operational framework and current initiatives demonstrating the effectiveness of locally-based youth support. The second explores the collective's aspirations for future initiatives, specifically focusing on two key proposals: establishing a full-time youth connector position and developing a community youth hub.

 Key findings demonstrate the transformative potential of volunteer-driven, culturally responsive youth support strategies. The research highlights the importance of contextual understanding, community ownership, and holistic approaches to youth development. Particularly significant is the model's ability to navigate the bicultural landscape of Aotearoa, providing a nuanced approach that respects both indigenous and contemporary cultural frameworks.

Theoretically grounded in Positive Youth Development (PYD) frameworks and indigenous cultural perspectives, the research bridges Western psychological approaches with local cultural understanding. The study reveals how a community-centric model of youth support can effectively address the complex needs of rural youth, emphasizing cultural identity, collective empowerment, and local knowledge.

The study contributes to broader discussions on youth support, community development, and cultural resilience. It challenges traditional, standardized intervention models by showcasing the effectiveness of locally embedded, flexible support strategies. The research provides valuable insights for community organizations, policymakers, educational institutions, and social service providers seeking innovative approaches to youth engagement.
Further, the findings offer a replicable framework for understanding and supporting youth development in rural contexts, with broader implications for community support strategies that prioritize local knowledge, cultural responsiveness, and collective empowerment.

Ultimately, the research presents a compelling argument for understanding youth development as a collaborative, contextually embedded process. It demonstrates that meaningful community support emerges from within, driven by local aspirations, cultural understanding, and collective investment in young people's potential.

year: 2025