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: Slim and scum: Natural products from land and sea

authors: Prinsep, Michèle R.

subjects: chemistry

abstract: To a natural-products chemist, the term "natural products" does not refer to all compounds from natural sources, as the name might imply. It is specifically used to refer to compounds known as secondary metabolites, structurally complex molecules, often of unknown function, with very limited biological distribution.

text: Slim and scum: Natural products from land and sea To a natural-products chemist, the term "natural products" does not refer to all compounds from natural sources, as the name might imply. It is specifically used to refer to compounds known as secondary metabolites, structurally complex molecules, often of unknown function, with very limited biological distribution.

year: 2000

title: Breaking barriers and empowering perspectives: Centering women's voices in the mongrel mob wāhine toa

authors: Arnold, Annaliese

subjects: gang research

abstract: Gang communities in Aotearoa New Zealand have traditionally been sites of masculinity where specific forms of 'maleness' - including resistance to authority, antisocial behaviour, and expressions of violence - are embraced, expressed, and enforced through various internal cultural norms and reactions to the outside world. The dominant narrative that informs public perceptions of New Zealand gangs is often centered on crime, poverty, and Indigeneity. Much less is known about the role of women in these communities, particularly as their voices have only recently emerged from one of the largest gang chapters in the country. This research, conducted in close collaboration with wāhine within the Mongrel Mob Kingdom's first female-only chapter, Mongrel Mob Wāhine Toa, uses a participatory action research approach with photovoice methodology. Drawing on the personal narratives of six wāhine, this study aims to better understand their perspectives and experiences of contributing to a fledgling movement that privileges women within a predominantly male-centered gang environment. Photovoice is used alongside semi-structured interviews to provide depth and breadth to the data, allowing the wāhine to visually and verbally express their experiences and perspectives. Themes include navigating marginality, empowerment, and resistance. The long-range goal of this work is to inform context-sensitive policies and interventions for wāhine in gangs in Aotearoa. By foregrounding the perspective of wāhine, this study contributes to breaking down barriers and reshaping discourses around women in gangs, with implications for well-being and empowerment.

text: Breaking barriers and empowering perspectives: Centering women's voices in the mongrel mob wāhine toa Gang communities in Aotearoa New Zealand have traditionally been sites of masculinity where specific forms of 'maleness' - including resistance to authority, antisocial behaviour, and expressions of violence - are embraced, expressed, and enforced through various internal cultural norms and reactions to the outside world. The dominant narrative that informs public perceptions of New Zealand gangs is often centered on crime, poverty, and Indigeneity. Much less is known about the role of women in these communities, particularly as their voices have only recently emerged from one of the largest gang chapters in the country. This research, conducted in close collaboration with wāhine within the Mongrel Mob Kingdom's first female-only chapter, Mongrel Mob Wāhine Toa, uses a participatory action research approach with photovoice methodology. Drawing on the personal narratives of six wāhine, this study aims to better understand their perspectives and experiences of contributing to a fledgling movement that privileges women within a predominantly male-centered gang environment. Photovoice is used alongside semi-structured interviews to provide depth and breadth to the data, allowing the wāhine to visually and verbally express their experiences and perspectives. Themes include navigating marginality, empowerment, and resistance. The long-range goal of this work is to inform context-sensitive policies and interventions for wāhine in gangs in Aotearoa. By foregrounding the perspective of wāhine, this study contributes to breaking down barriers and reshaping discourses around women in gangs, with implications for well-being and empowerment.

year: 2025