title: Open-source tool for heat exchanger network synthesis

authors: Hall, Keegan

abstract: The synthesis of heat exchanger networks (HEN) is not a trivial task due to the mixed integer and non-linear nature of the optimisation problem, yet it can provide significant cost and energy use savings to an industrial processing site. Many HEN synthesis models are developed using propriety solvers, which make it difficult for industrial companies to realise the potential of optimisation. This paper introduces a new open-source tool for HEN synthesis built in Python using the GEKKO library, which interfaces with the solver APOPT. The tool features three different synthesis methods, two of which utilise a two-step method where step one aims to initialise or narrow the search space prior to global optimisation in the second synthesis step. A unique feature of this work compared to previous HEN synthesis studies is the application of a true driving force constraint, dQ/dA, (instead of the conventional, but at times crude, minimum approach temperature, ∆Tmin) to provide feasible initial variable values to the second step. To demonstrate the current progress in developing the open-source tool, network solutions obtained by the tool were purposefully compared with the best reported solutions for three common case studies in HEN synthesis literature. For a small problem, the tool achieved a solution within 0.02 % of the best literature solution and attained a solution for the two larger problems within 4 % and 21% of the best literature solution. Before the tool can be made publicly available, further work is needed to implement a non-isothermal mixing model across stream splits, which is expected to yield a more optimal HEN.

text: Open-source tool for heat exchanger network synthesis The synthesis of heat exchanger networks (HEN) is not a trivial task due to the mixed integer and non-linear nature of the optimisation problem, yet it can provide significant cost and energy use savings to an industrial processing site. Many HEN synthesis models are developed using propriety solvers, which make it difficult for industrial companies to realise the potential of optimisation. This paper introduces a new open-source tool for HEN synthesis built in Python using the GEKKO library, which interfaces with the solver APOPT. The tool features three different synthesis methods, two of which utilise a two-step method where step one aims to initialise or narrow the search space prior to global optimisation in the second synthesis step. A unique feature of this work compared to previous HEN synthesis studies is the application of a true driving force constraint, dQ/dA, (instead of the conventional, but at times crude, minimum approach temperature, ∆Tmin) to provide feasible initial variable values to the second step. To demonstrate the current progress in developing the open-source tool, network solutions obtained by the tool were purposefully compared with the best reported solutions for three common case studies in HEN synthesis literature. For a small problem, the tool achieved a solution within 0.02 % of the best literature solution and attained a solution for the two larger problems within 4 % and 21% of the best literature solution. Before the tool can be made publicly available, further work is needed to implement a non-isothermal mixing model across stream splits, which is expected to yield a more optimal HEN.

year: 2022-09-05

title: Patent-collaboration: Licensing, patent pools, patents commons, open source and communities of innovation

authors: Kingsbury, Anna

abstract: Patent pools and other models of patent collaboration are a growing feature of the patent landscape internationally. Patent collaboration can be a means of overcoming patent thicket problems, avoiding costly patent infringement litigation, reducing transaction costs and promoting efficiency and innovation. Patent co-operation is also used, commonly as a result of some form of regulatory intervention, where there are urgent issues of strong public concern. Access to medicines and climate change are examples. However, patent collaboration can raise competition law issues.
This article reviews the models for collaboration internationally, considers specific examples and considers the application of competition law and possible competition law barriers to collaboration in the New Zealand context. It argues that patent collaboration can now be used as a possible approach to promoting innovation in appropriate industries in New Zealand.

text: Patent-collaboration: Licensing, patent pools, patents commons, open source and communities of innovation Patent pools and other models of patent collaboration are a growing feature of the patent landscape internationally. Patent collaboration can be a means of overcoming patent thicket problems, avoiding costly patent infringement litigation, reducing transaction costs and promoting efficiency and innovation. Patent co-operation is also used, commonly as a result of some form of regulatory intervention, where there are urgent issues of strong public concern. Access to medicines and climate change are examples. However, patent collaboration can raise competition law issues.
This article reviews the models for collaboration internationally, considers specific examples and considers the application of competition law and possible competition law barriers to collaboration in the New Zealand context. It argues that patent collaboration can now be used as a possible approach to promoting innovation in appropriate industries in New Zealand.

year: 2013

title: Approaching Māori language through meaning: The predominance of Indo-European models of relationships within propositions

authors: Whaanga, Hēmi

subjects: Te reo Māori

abstract: In every language, there are relationships between predicators (such as, for example, 'go'/'haere') and arguments (such as, for example, ‘James'/'Hēmi’). One such relationship that has been proposed is that of agency. Thus, in 'James goes'/ ‘E haere ana a Hēmi’), 'James'/'Hēmi' can be said to be the agent of the action 'go'/'haere'. Much of the international literature on relationships of this type is based on research on English and it has been claimed that the relationships that have been identified are universals. However, there may be differences among languages, differences that are attributable to the fact that different languages encode different ways of perceiving divisions in perceptual space. My aim here is to demonstrate, with reference to a number of different models of predicator/ argument relations, that most of them are based on assumptions that derive from the structure of Indo-European languages, English in particular. In Part 2 of this paper (to appear in a subsequent issue of this Journal), the implications of this discussion will be examined with reference to an analysis of Māori in terms of relationships within propositions.

text: Approaching Māori language through meaning: The predominance of Indo-European models of relationships within propositions In every language, there are relationships between predicators (such as, for example, 'go'/'haere') and arguments (such as, for example, ‘James'/'Hēmi’). One such relationship that has been proposed is that of agency. Thus, in 'James goes'/ ‘E haere ana a Hēmi’), 'James'/'Hēmi' can be said to be the agent of the action 'go'/'haere'. Much of the international literature on relationships of this type is based on research on English and it has been claimed that the relationships that have been identified are universals. However, there may be differences among languages, differences that are attributable to the fact that different languages encode different ways of perceiving divisions in perceptual space. My aim here is to demonstrate, with reference to a number of different models of predicator/ argument relations, that most of them are based on assumptions that derive from the structure of Indo-European languages, English in particular. In Part 2 of this paper (to appear in a subsequent issue of this Journal), the implications of this discussion will be examined with reference to an analysis of Māori in terms of relationships within propositions.

year: 2001-09