title: Ultrasonic Air Leak Detection: An Investigation to Improve Accuracy of Leak Rate Estimation

authors: Wolstencroft, Hamish Roger

subjects: ultrasonic

abstract: A compressed air test rig was designed to develop new procedures and improve the reliability of results that are obtained when conducting a leak survey using an Ultrasonic leak detector such as the UE Systems Ultraprobe.

A test rig was designed that allowed the pressure of air in a compressed air system to be controlled by a regulator. This allowed experiments to be conducted that were able to recreate leak situations in a controlled environment. The pressure of the air through the test rig was measured both at the supply end and at the proximity of the leak site, while the volume flow rate was measured at the supply end of the rig.

A number of leak geometries were examined, with compressed air being passed through open ended tubing and also discs with different leak geometries, some round holes and some rectangular. Initial studies were also carried out on flange leaks and pinpricks and slits in lengths of tubing. These were omitted from the study at this stage to allow further experimentation to be conducted in both areas.

The experimentation was carried out using an Ultraprobe 9000 leak detector which was positioned at a set distance from the leak at a series of angles to the flow. The ultrasound level was measured at each point and compared with the pressure and volume flow rate of the air in the system.

The results showed that the ideal angle to ensure the maximum level of ultrasound is at 30 to the axis of the leak. While the optimum distance for ensuring a consistent level of ultrasound is 150mm from the leak.

The length of any air lines branching from the main distribution network is shown to be an important factor when quantifying the volumetric flow rate of air from an open ended tube or tubing with a significant orifice in it. The pressure drop in a 1m length of tubing was shown to be approximately 50%, and if you consider that often the flow rate being used has been obtained using the outside diameter of the tubing rather than the inside diameter this can become a considerable over estimation of leak rate.

The geometry of a regular shaped orifice, such as a round, or rectangular hole was shown to have little to no effect on the flow rate through it for a constant area. However a coefficient of discharge to account for imperfections in the flow was developed for round and rectangular geometries, these were 0.74 for a round hole and 0.79 for a rectangular hole. These correction factors in tandem with the length effect factor for tubing and the improvements to the measurement procedure, allow a higher degree of accuracy to be obtained when conducting a leak survey.

text: Ultrasonic Air Leak Detection: An Investigation to Improve Accuracy of Leak Rate Estimation A compressed air test rig was designed to develop new procedures and improve the reliability of results that are obtained when conducting a leak survey using an Ultrasonic leak detector such as the UE Systems Ultraprobe.

A test rig was designed that allowed the pressure of air in a compressed air system to be controlled by a regulator. This allowed experiments to be conducted that were able to recreate leak situations in a controlled environment. The pressure of the air through the test rig was measured both at the supply end and at the proximity of the leak site, while the volume flow rate was measured at the supply end of the rig.

A number of leak geometries were examined, with compressed air being passed through open ended tubing and also discs with different leak geometries, some round holes and some rectangular. Initial studies were also carried out on flange leaks and pinpricks and slits in lengths of tubing. These were omitted from the study at this stage to allow further experimentation to be conducted in both areas.

The experimentation was carried out using an Ultraprobe 9000 leak detector which was positioned at a set distance from the leak at a series of angles to the flow. The ultrasound level was measured at each point and compared with the pressure and volume flow rate of the air in the system.

The results showed that the ideal angle to ensure the maximum level of ultrasound is at 30 to the axis of the leak. While the optimum distance for ensuring a consistent level of ultrasound is 150mm from the leak.

The length of any air lines branching from the main distribution network is shown to be an important factor when quantifying the volumetric flow rate of air from an open ended tube or tubing with a significant orifice in it. The pressure drop in a 1m length of tubing was shown to be approximately 50%, and if you consider that often the flow rate being used has been obtained using the outside diameter of the tubing rather than the inside diameter this can become a considerable over estimation of leak rate.

The geometry of a regular shaped orifice, such as a round, or rectangular hole was shown to have little to no effect on the flow rate through it for a constant area. However a coefficient of discharge to account for imperfections in the flow was developed for round and rectangular geometries, these were 0.74 for a round hole and 0.79 for a rectangular hole. These correction factors in tandem with the length effect factor for tubing and the improvements to the measurement procedure, allow a higher degree of accuracy to be obtained when conducting a leak survey.

year: 2008

title: Factors that sustain curriculum leaders in the profession: Perspectives of secondary school agricultural and horticultural science teachers in New Zealand

authors: Low, Coadette Sandra

subjects: Agricultural and Horticultural Science

abstract: With the primary industries being of national significance to the New Zealand economy, it is experienced and passionate Agricultural and Horticultural Science teachers who are needed to engage, motivate, and inspire the next generation coming through. These teachers lead learning in and out of the classroom but are also actively involved in various leadership roles that have an impact on the subject. They are curriculum leaders. It is important to understand what factors motivate and sustain their professional work, and remain in the profession. 

Through the positive lens of appreciative inquiry, a mixed-method approach was used with this research. Data collection was broken down into two phases. Phase One, an online questionnaire, which allowed for insight to be gathered from a wide range of respondents and Phase Two, semi-structured interviews which allowed for a deeper understanding through individual narratives. 

The findings from this research highlighted that the main factors that sustain these curriculum leaders is the relational aspect with the students - being part of their successes, journey and inspiring them, but also the absolute relevance of the subject content. When starting out teaching the subject, a good support network, particularly a mentor, is critical for success. Continued support is crucial for ensuring that these curriculum leaders are supported throughout their journey, regardless of their career stage, and the support received will influence motivation, engagement, and job satisfaction. No career comes without challenges and constraints with the main ones being identified as the imbalanced ratio between workload and hours in the day, and curriculum perception from the senior leadership team and colleagues.

The senior leadership team has a large influence on school culture and job satisfaction and therefore retention rate. Those leaders who embrace transformational and relational leadership attributes develop trust relationships, support their staff, and allow teachers to have agency and autonomy to lead the curriculum within the subject. Strategies to address motivation and engagement in teachers are transferable, and therefore could be implemented across all curriculum areas.

text: Factors that sustain curriculum leaders in the profession: Perspectives of secondary school agricultural and horticultural science teachers in New Zealand With the primary industries being of national significance to the New Zealand economy, it is experienced and passionate Agricultural and Horticultural Science teachers who are needed to engage, motivate, and inspire the next generation coming through. These teachers lead learning in and out of the classroom but are also actively involved in various leadership roles that have an impact on the subject. They are curriculum leaders. It is important to understand what factors motivate and sustain their professional work, and remain in the profession. 

Through the positive lens of appreciative inquiry, a mixed-method approach was used with this research. Data collection was broken down into two phases. Phase One, an online questionnaire, which allowed for insight to be gathered from a wide range of respondents and Phase Two, semi-structured interviews which allowed for a deeper understanding through individual narratives. 

The findings from this research highlighted that the main factors that sustain these curriculum leaders is the relational aspect with the students - being part of their successes, journey and inspiring them, but also the absolute relevance of the subject content. When starting out teaching the subject, a good support network, particularly a mentor, is critical for success. Continued support is crucial for ensuring that these curriculum leaders are supported throughout their journey, regardless of their career stage, and the support received will influence motivation, engagement, and job satisfaction. No career comes without challenges and constraints with the main ones being identified as the imbalanced ratio between workload and hours in the day, and curriculum perception from the senior leadership team and colleagues.

The senior leadership team has a large influence on school culture and job satisfaction and therefore retention rate. Those leaders who embrace transformational and relational leadership attributes develop trust relationships, support their staff, and allow teachers to have agency and autonomy to lead the curriculum within the subject. Strategies to address motivation and engagement in teachers are transferable, and therefore could be implemented across all curriculum areas.

year: 2023

title: 'Kōrero Tuku Iho': Reconfiguring Oral History and Oral Tradition

authors: Mahuika, Nepia

subjects: History

abstract: The studies of oral history and oral tradition each have their own distinctive bodies of literature and preferred methodologies, yet share significant overlaps that make them difficult to differentiate. For many indigenous peoples, oral histories and traditions are key to their their past, present, and future lives, and are rarely considered separate. This thesis examines the differences and similarities between the studies of oral history and oral tradition. It explores how these areas of research converge and diverge in form, politics, practice, and theory, and the extent to which they resonate within a specific ‘indigenous’ context and community.
The thesis draws on the life narrative interviews of four generations of Ngāti Porou descendents, the second largest tribal group in New Zealand, whose home boundaries extend from Potikirua in the north to Te Toka-a-Taiau in the south on the East Coast of the North Island. Drawing on these voices, this study offers a commentary on the form and nature of oral traditions and histories from an indigenous perspective, and explores the ways they converge and depart from ‘international’ understandings. An exploration of these intersections offers insights to the ways oral history and oral traditions might be reconsidered as distinctive fields of study. Reconfigured through an indigenous frame of reference, this thesis challenges scholars of both oral history and oral tradition to expand their conceptions. Likewise, it urges indigenous scholars to consider more deeply the work of oral historians and oral traditionalists to further enhance their scholarship. Moreover, this thesis revisits the intellectual and conceptual territory that names and claims oral history and oral tradition, and invites all those who work in these areas to develop a more extensive comprehension of the interconnections that exist between each area of study.

text: 'Kōrero Tuku Iho': Reconfiguring Oral History and Oral Tradition The studies of oral history and oral tradition each have their own distinctive bodies of literature and preferred methodologies, yet share significant overlaps that make them difficult to differentiate. For many indigenous peoples, oral histories and traditions are key to their their past, present, and future lives, and are rarely considered separate. This thesis examines the differences and similarities between the studies of oral history and oral tradition. It explores how these areas of research converge and diverge in form, politics, practice, and theory, and the extent to which they resonate within a specific ‘indigenous’ context and community.
The thesis draws on the life narrative interviews of four generations of Ngāti Porou descendents, the second largest tribal group in New Zealand, whose home boundaries extend from Potikirua in the north to Te Toka-a-Taiau in the south on the East Coast of the North Island. Drawing on these voices, this study offers a commentary on the form and nature of oral traditions and histories from an indigenous perspective, and explores the ways they converge and depart from ‘international’ understandings. An exploration of these intersections offers insights to the ways oral history and oral traditions might be reconsidered as distinctive fields of study. Reconfigured through an indigenous frame of reference, this thesis challenges scholars of both oral history and oral tradition to expand their conceptions. Likewise, it urges indigenous scholars to consider more deeply the work of oral historians and oral traditionalists to further enhance their scholarship. Moreover, this thesis revisits the intellectual and conceptual territory that names and claims oral history and oral tradition, and invites all those who work in these areas to develop a more extensive comprehension of the interconnections that exist between each area of study.

year: 2012