title: Practical heat pump and storage integration into non-continuous processes: A hybrid approach utilizing insight based and nonlinear programming techniques

authors: Stampfli, Jan A.

subjects: Science & Technology

abstract: This paper focuses on industrial heat pump (HP) integration in non-continuous processes. To achieve the necessary time-wise process decoupling of the HP system, heat recovery loops (HRLs) with stratified storages are used. This design type can be modeled as a mixed integer nonlinear programming problem which often results in expensive mathematical formulations. The challenge is addressed by a practical method that combines the insight based approach of Pinch Analysis with mathematical programming techniques to give the engineer more flexibility for the application of the method and to avoid long computation times. By the use of the insight based methods, the solution space of the mathematical formulation is restricted, and thus its complexity is reduced to a nonlinear programming problem optimizing the temperature levels in the HP-HRL system. As an objective, total annual costs (TAC) of the HP-HRL system are minimized. The developed hybrid method is applied to a dairy site and compared in terms of approach temperatures, temperature lift of the HP, TAC, and greenhouse gas emissions to the existing methods. It is shown, that the hybrid method provides realistic approach temperatures in contrast to the existing insight based method.

text: Practical heat pump and storage integration into non-continuous processes: A hybrid approach utilizing insight based and nonlinear programming techniques This paper focuses on industrial heat pump (HP) integration in non-continuous processes. To achieve the necessary time-wise process decoupling of the HP system, heat recovery loops (HRLs) with stratified storages are used. This design type can be modeled as a mixed integer nonlinear programming problem which often results in expensive mathematical formulations. The challenge is addressed by a practical method that combines the insight based approach of Pinch Analysis with mathematical programming techniques to give the engineer more flexibility for the application of the method and to avoid long computation times. By the use of the insight based methods, the solution space of the mathematical formulation is restricted, and thus its complexity is reduced to a nonlinear programming problem optimizing the temperature levels in the HP-HRL system. As an objective, total annual costs (TAC) of the HP-HRL system are minimized. The developed hybrid method is applied to a dairy site and compared in terms of approach temperatures, temperature lift of the HP, TAC, and greenhouse gas emissions to the existing methods. It is shown, that the hybrid method provides realistic approach temperatures in contrast to the existing insight based method.

year: 2019

title: Platforms of Learning: The Ongoing Professonal Learning of Experienced Principals in Aotearoa New Zealand

authors: Grant, Peter

subjects: principal

abstract: Little is known about the professional learning of experienced school principals in New Zealand. How do they maintain sufficient learning to meet a diverse and fluid variety of leadership expectations after at least five years as principal? This research examines the professional learning habits and preferences of fifty two experienced school principals from a variety of schools covering subgroups of Years 1 – 13 within the Waikato and Bay of Plenty regions. A self-selected self-administered survey elicited responses on their use of over twenty three potential sources of learning. This approach was used to provide a fresh look at an under-researched topic. Research findings demonstrate that respondents used all learning sources to varying degrees according to factors such as personal preference, availability, cost, perceived quality, time and distance. A single best practice model remains elusive; those surveyed adopted eclectic approaches to their professional learning. The impact of information technologies and the role of professional principals’ associations in monitoring, promoting and supporting principals’ access to high quality professional learning are also discussed. Consideration of links between survey data and existing theory has resulted in the development of a framework of learning platforms for experienced principals. In addition, a number of dualities are highlighted. Together the proposed learning platforms and dualities provide a conceptual mechanism for the planning of deliberate professional learning and directions for further research.

text: Platforms of Learning: The Ongoing Professonal Learning of Experienced Principals in Aotearoa New Zealand Little is known about the professional learning of experienced school principals in New Zealand. How do they maintain sufficient learning to meet a diverse and fluid variety of leadership expectations after at least five years as principal? This research examines the professional learning habits and preferences of fifty two experienced school principals from a variety of schools covering subgroups of Years 1 – 13 within the Waikato and Bay of Plenty regions. A self-selected self-administered survey elicited responses on their use of over twenty three potential sources of learning. This approach was used to provide a fresh look at an under-researched topic. Research findings demonstrate that respondents used all learning sources to varying degrees according to factors such as personal preference, availability, cost, perceived quality, time and distance. A single best practice model remains elusive; those surveyed adopted eclectic approaches to their professional learning. The impact of information technologies and the role of professional principals’ associations in monitoring, promoting and supporting principals’ access to high quality professional learning are also discussed. Consideration of links between survey data and existing theory has resulted in the development of a framework of learning platforms for experienced principals. In addition, a number of dualities are highlighted. Together the proposed learning platforms and dualities provide a conceptual mechanism for the planning of deliberate professional learning and directions for further research.

year: 2011

title: Keeping Chooks at Home in the Waikato:  Exploring Postcolonial, Feminist and  Kaupapa M ori Perspectives

authors: Burnett, Zavier

subjects: Chooks

abstract: This thesis considers the narratives of eight M ori chook keepers from the Waikato rohe, Aotearoa. The Waikato rohe has been selected due to its significant history of M ori horticultural and agricultural practises, including chook keeping. 

I build on the growing corpus of m tauranga about indigenous studies. Using a postcolonial, feminist and Kaupapa M ori theoretical framework, I undertook five semi-structured interviews and one focus r p  with M ori kaum tua. This thesis does not attempt to represent all M ori. There may be considerable difference between wh nau, hap  and iwi practices. However, the rangahau provides insights into the views of eight individuals and their experiences with chooks. I have also utilised Country Calendar (1970; 1977a; 1977b and 1980) episodes and children's pukapuka such as Nanny Mihi's Garden (Drewery 2002) for the purposes of discourse analysis. 

By listening to these stories, kaupapa including race, class and ethnicity emerge that affect the participants' everyday lives as chook keepers. The participants view chooks in a variety of ways. First, as a means of food production. By integrating chooks into their communities, the participants are able to provide a nutritious and low-cost kai source for themselves and their wh nau. This attempts to at least in part address their poverty problems. Second, as a hybridised P keh  and M ori kararehe. Third, as hysterical, comical, silly and helpless. I explore these issues within the broader context of colonial, neocolonial and anticolonial practices.

text: Keeping Chooks at Home in the Waikato:  Exploring Postcolonial, Feminist and  Kaupapa M ori Perspectives This thesis considers the narratives of eight M ori chook keepers from the Waikato rohe, Aotearoa. The Waikato rohe has been selected due to its significant history of M ori horticultural and agricultural practises, including chook keeping. 

I build on the growing corpus of m tauranga about indigenous studies. Using a postcolonial, feminist and Kaupapa M ori theoretical framework, I undertook five semi-structured interviews and one focus r p  with M ori kaum tua. This thesis does not attempt to represent all M ori. There may be considerable difference between wh nau, hap  and iwi practices. However, the rangahau provides insights into the views of eight individuals and their experiences with chooks. I have also utilised Country Calendar (1970; 1977a; 1977b and 1980) episodes and children's pukapuka such as Nanny Mihi's Garden (Drewery 2002) for the purposes of discourse analysis. 

By listening to these stories, kaupapa including race, class and ethnicity emerge that affect the participants' everyday lives as chook keepers. The participants view chooks in a variety of ways. First, as a means of food production. By integrating chooks into their communities, the participants are able to provide a nutritious and low-cost kai source for themselves and their wh nau. This attempts to at least in part address their poverty problems. Second, as a hybridised P keh  and M ori kararehe. Third, as hysterical, comical, silly and helpless. I explore these issues within the broader context of colonial, neocolonial and anticolonial practices.

year: 2006