title: Potential of supercapacitors in novel power converters as semi-ideal lossless voltage droppers

authors: Ariyarathna, Thilanga

subjects: Science & Technology

abstract: Electrical physics text book theory tells us that charging a capacitor is much less efficient than replenishing the energy in a discharged electro-chemical battery. If a fully discharged capacitor is pumped with a charge of Q coulombs, it stores 1/2QV while dissipating the same amount of energy in the loop resistance. However, if the same charge is pumped into a re-chargeable electrochemical cell of voltage V the energy stored in the cell is QV, while the wasted energy is determined by the loop resistance and the voltage difference across the resistance. If a rechargeable battery pack is to be replaced by a supercapacitor module, this difference could seriously affect the design of power converters required, since the power converter should stop charging at a certain point to avoid overcharging the capacitor bank. However, if a useful resistive load such as heater, DC-DC converter, inverter or a lamp load is used as a part of the loop resistance in a capacitor charging loop, a significant part of this loss can be recovered. One example of this is in the supercapacitor assisted low drop-out regulator (SCALDO) technique. This paper will detail the concept of circumvention of RC loop charging loss, theoretically quantifying the same in a generalized circuit, demonstrating how this can be applied in completely novel circuit topologies such as the supercapacitor assisted LED (SCALED) converter. The paper will provide experimental results of selected SCALDO implementations and early results of SCALED technique to support this theory.

text: Potential of supercapacitors in novel power converters as semi-ideal lossless voltage droppers Electrical physics text book theory tells us that charging a capacitor is much less efficient than replenishing the energy in a discharged electro-chemical battery. If a fully discharged capacitor is pumped with a charge of Q coulombs, it stores 1/2QV while dissipating the same amount of energy in the loop resistance. However, if the same charge is pumped into a re-chargeable electrochemical cell of voltage V the energy stored in the cell is QV, while the wasted energy is determined by the loop resistance and the voltage difference across the resistance. If a rechargeable battery pack is to be replaced by a supercapacitor module, this difference could seriously affect the design of power converters required, since the power converter should stop charging at a certain point to avoid overcharging the capacitor bank. However, if a useful resistive load such as heater, DC-DC converter, inverter or a lamp load is used as a part of the loop resistance in a capacitor charging loop, a significant part of this loss can be recovered. One example of this is in the supercapacitor assisted low drop-out regulator (SCALDO) technique. This paper will detail the concept of circumvention of RC loop charging loss, theoretically quantifying the same in a generalized circuit, demonstrating how this can be applied in completely novel circuit topologies such as the supercapacitor assisted LED (SCALED) converter. The paper will provide experimental results of selected SCALDO implementations and early results of SCALED technique to support this theory.

year: 2017

title: Teu le vā: Cultivating the space between: An investigation into Samoan-Palagi intimate partner relationships.

authors: Finnigan, Hannah Sarah

subjects: flourishing

abstract: This thesis investigates how Samoan-Palagi intimate partner relationships flourish. Key areas of investigation include important factors influencing participants’ relationships, what flourishing means to participants, how the flourishing of each partner is supported by the relationship, and how partners negotiate the vā fealoaloa’i (relational space) between them. A qualitative research design was used to examine the lived experiences of two Samoan-Palagi couples. The theoretical framework for this research was informed by the Uputāua Therapeutic Approach, fono fa’atalatalanoa (narrative dialogue) and positioning myself as a naive learner in the research. Data collection involved multiple interviews, first with both partners of each couple and then a follow-up interview with each individual. The information shared in these interviews is presented in two case studies. The findings of this research advocate for flourishing relationships as a process, and suggest that by looking after the relational space and constantly attending to the relationship, it may flourish and grow. The relational space does not refer to a single domain, but is holistic and addresses each partner in their totality. Flourishing, for participants, involves the development of interdependence by navigating a continuum of individual and collective needs, in order to support the relationship. This research provides insight into how vā fealoaloa’i (the relational space) and teu le vā (tending to/looking after this space) can operate in intimate partner relationships.

text: Teu le vā: Cultivating the space between: An investigation into Samoan-Palagi intimate partner relationships. This thesis investigates how Samoan-Palagi intimate partner relationships flourish. Key areas of investigation include important factors influencing participants’ relationships, what flourishing means to participants, how the flourishing of each partner is supported by the relationship, and how partners negotiate the vā fealoaloa’i (relational space) between them. A qualitative research design was used to examine the lived experiences of two Samoan-Palagi couples. The theoretical framework for this research was informed by the Uputāua Therapeutic Approach, fono fa’atalatalanoa (narrative dialogue) and positioning myself as a naive learner in the research. Data collection involved multiple interviews, first with both partners of each couple and then a follow-up interview with each individual. The information shared in these interviews is presented in two case studies. The findings of this research advocate for flourishing relationships as a process, and suggest that by looking after the relational space and constantly attending to the relationship, it may flourish and grow. The relational space does not refer to a single domain, but is holistic and addresses each partner in their totality. Flourishing, for participants, involves the development of interdependence by navigating a continuum of individual and collective needs, in order to support the relationship. This research provides insight into how vā fealoaloa’i (the relational space) and teu le vā (tending to/looking after this space) can operate in intimate partner relationships.

year: 2017

title: Te Whatu Kakahu: Assessment in Kaupapa Maori Early Childhood Practice

authors: Rameka, Lesley Kay

subjects: Kaupapa Maori

abstract: Through the exploration of Kaupapa Māori assessment approaches, I examine the reclaiming and reframing of Māori ways of knowing and being within early childhood practice. Assessment is the vehicle for reclaiming and reframing while Kaupapa Māori theory is the fuel that ignites and drives the vehicle.

The effects of successive education policies remain today with Māori children, and their families continuing to disengage from education and consistently receiving disproportionately lower outcomes, opportunities and benefits. Reclaiming and reframing Māori ways of knowing and being within early childhood assessment thinking and practice is a means of addressing the cultural and educational disparities faced by Māori children within an education system that upholds western cultural and educational superiority, privilege and truths.  Key questions in this process of reclaiming and reframing are: Who has the power to define?  Whose truths are being reflected and how are these truths constructed? 

The metaphor of whatu kākahu or weaving of clothing has been used to frame this thesis. The process has involved weaving the Kaupapa Māori theory elements of conscientisation, resistance, transformative praxis and Māori ways of knowing and being, across and within historical, cultural and educational paradigms and understandings, to fashion assessment kākahu that afford comfort, warmth and flexibility in a contemporary early childhood context. This research case studies the progress of three Māori early childhood services and kōhanga reo towards the development of Kaupapa Māori early childhood assessment understandings and framings (kākahu), that reflect their particular ways of knowing and being, context and aspirations for children. This thesis has been about their assessment journeys. These journeys are a work in progress and that work continues.

A qualitative, Kaupapa Māori research methodology was used to gather, collate and analyse data in this research.  In accordance with Kaupapa Māori research aspirations and expectations, this research focuses on areas of importance and concern for Māori, and involved retrieving space for Māori voices to be heard. This research can be seen as a means of privileging Māori approaches, perspectives and ways of knowing and being in early childhood assessment practice.

Kaupapa Māori assessment is an important agenda for early childhood.   It builds upon Māori philosophical and epistemological understandings that express Māori ways of knowing and being. Kaupapa Māori assessment is able to contribute significantly to children’s learning and potential growth and is an important tool in constructing educational outcomes for Māori children. It is therefore an important agenda for early childhood.

text: Te Whatu Kakahu: Assessment in Kaupapa Maori Early Childhood Practice Through the exploration of Kaupapa Māori assessment approaches, I examine the reclaiming and reframing of Māori ways of knowing and being within early childhood practice. Assessment is the vehicle for reclaiming and reframing while Kaupapa Māori theory is the fuel that ignites and drives the vehicle.

The effects of successive education policies remain today with Māori children, and their families continuing to disengage from education and consistently receiving disproportionately lower outcomes, opportunities and benefits. Reclaiming and reframing Māori ways of knowing and being within early childhood assessment thinking and practice is a means of addressing the cultural and educational disparities faced by Māori children within an education system that upholds western cultural and educational superiority, privilege and truths.  Key questions in this process of reclaiming and reframing are: Who has the power to define?  Whose truths are being reflected and how are these truths constructed? 

The metaphor of whatu kākahu or weaving of clothing has been used to frame this thesis. The process has involved weaving the Kaupapa Māori theory elements of conscientisation, resistance, transformative praxis and Māori ways of knowing and being, across and within historical, cultural and educational paradigms and understandings, to fashion assessment kākahu that afford comfort, warmth and flexibility in a contemporary early childhood context. This research case studies the progress of three Māori early childhood services and kōhanga reo towards the development of Kaupapa Māori early childhood assessment understandings and framings (kākahu), that reflect their particular ways of knowing and being, context and aspirations for children. This thesis has been about their assessment journeys. These journeys are a work in progress and that work continues.

A qualitative, Kaupapa Māori research methodology was used to gather, collate and analyse data in this research.  In accordance with Kaupapa Māori research aspirations and expectations, this research focuses on areas of importance and concern for Māori, and involved retrieving space for Māori voices to be heard. This research can be seen as a means of privileging Māori approaches, perspectives and ways of knowing and being in early childhood assessment practice.

Kaupapa Māori assessment is an important agenda for early childhood.   It builds upon Māori philosophical and epistemological understandings that express Māori ways of knowing and being. Kaupapa Māori assessment is able to contribute significantly to children’s learning and potential growth and is an important tool in constructing educational outcomes for Māori children. It is therefore an important agenda for early childhood.

year: 2012