title: Measurement of natural convection heat transfer in an attic shaped enclosure

authors: Anderson, Timothy Nicholas

subjects: solar

abstract: Heat transfer by natural convection in triangular enclosures is an area of significant importance in applications such as the design of greenhouses, attics and solar water heaters. However, given its significance to these areas it has not been widely examined. In this study, the natural convection heat transfer coefficients for air in an attic shaped enclosure were determined for Grashof Numbers over the range of 10⁷ to 10⁹. It was found that the measured heat transfer coefficients could be predicted to within 5% by Ridouane and Campo’ (2005) equation (Eqn. 1) for natural convection in a triangular enclosure previously developed for Grashof Numbers in the range 10⁵ and 10⁶. 
Nu= 0.286A⁻⁰•²⁸⁶ Gr¼    (1)
As such, it is suggested that this equation may be suitable for predicting the natural convection heat transfer coefficients in full scale attic enclosures.

text: Measurement of natural convection heat transfer in an attic shaped enclosure Heat transfer by natural convection in triangular enclosures is an area of significant importance in applications such as the design of greenhouses, attics and solar water heaters. However, given its significance to these areas it has not been widely examined. In this study, the natural convection heat transfer coefficients for air in an attic shaped enclosure were determined for Grashof Numbers over the range of 10⁷ to 10⁹. It was found that the measured heat transfer coefficients could be predicted to within 5% by Ridouane and Campo’ (2005) equation (Eqn. 1) for natural convection in a triangular enclosure previously developed for Grashof Numbers in the range 10⁵ and 10⁶. 
Nu= 0.286A⁻⁰•²⁸⁶ Gr¼    (1)
As such, it is suggested that this equation may be suitable for predicting the natural convection heat transfer coefficients in full scale attic enclosures.

year: 2008

title: A survey on compositional algorithms for verification and synthesis in supervisory control

authors: Malik, Robi

subjects: software engineering

abstract: This survey gives an overview of the current research on compositional algorithms for verification and synthesis of modular systems modelled as interacting finite-state machines. Compositional algorithms operate by repeatedly simplifying individual components of a large system, replacing them by smaller so-called abstractions, while preserving critical properties. In this way, the exponential growth of the state space can be limited, making it possible to analyse much bigger state spaces than possible by standard state space exploration. This paper gives an introduction to the principles underlying compositional methods, followed by a survey of algorithmic solutions from the recent literature that use compositional methods to analyse systems automatically. The focus is on applications in supervisory control of discrete event systems, particularly on methods that verify critical properties or synthesise controllable and nonblocking supervisors.

text: A survey on compositional algorithms for verification and synthesis in supervisory control This survey gives an overview of the current research on compositional algorithms for verification and synthesis of modular systems modelled as interacting finite-state machines. Compositional algorithms operate by repeatedly simplifying individual components of a large system, replacing them by smaller so-called abstractions, while preserving critical properties. In this way, the exponential growth of the state space can be limited, making it possible to analyse much bigger state spaces than possible by standard state space exploration. This paper gives an introduction to the principles underlying compositional methods, followed by a survey of algorithmic solutions from the recent literature that use compositional methods to analyse systems automatically. The focus is on applications in supervisory control of discrete event systems, particularly on methods that verify critical properties or synthesise controllable and nonblocking supervisors.

year: 2023-08-21

title: Governance of water based on responsible use – an elegant solution?‎

authors: Te Aho, Linda

abstract: The inspiration for this chapter is a proposal said to represent "a paradigm shift" for the governance of freshwater, articulated by Sir Edward Taihakurei Durie in 2014. ² Arising out of challenges to a government plan to sell its shares in powergenerating companies,³ the Durie proposal has at its heart a possibility for reconciling Maori rights and interests and wider general interests in freshwater. It is based on the assumption that Maori and the general public have a legitimate interest in the natural water regimes of the country. However, the source of the interest is not the same. The Maori interest is proprietary and is sourced in their status as the indigenous first peoples of the land who were guaranteed continuation of their tino rangatiratanga in respect of their lands and waters in Te Tiriti o Waitangi.⁴ The public interest is sourced in the British laws that superimposed Maori laws through processes of colonisation. The heart of the Durie proposal is that those utilising water for commercial purposes should be charged and that an independent commission would be responsible for overseeing charging and revenue collection and disbursement. A proportion of the funds would be allocated to Maori authorities in recognition of the Maori interest. Whether in public or Maori hands, the funds should be applied to the maintenance or improvement of the natural water bodies of the area or the assurance of water supplies to all homes. In short, the proposal focuses upon responsibility.

text: Governance of water based on responsible use – an elegant solution?‎ The inspiration for this chapter is a proposal said to represent "a paradigm shift" for the governance of freshwater, articulated by Sir Edward Taihakurei Durie in 2014. ² Arising out of challenges to a government plan to sell its shares in powergenerating companies,³ the Durie proposal has at its heart a possibility for reconciling Maori rights and interests and wider general interests in freshwater. It is based on the assumption that Maori and the general public have a legitimate interest in the natural water regimes of the country. However, the source of the interest is not the same. The Maori interest is proprietary and is sourced in their status as the indigenous first peoples of the land who were guaranteed continuation of their tino rangatiratanga in respect of their lands and waters in Te Tiriti o Waitangi.⁴ The public interest is sourced in the British laws that superimposed Maori laws through processes of colonisation. The heart of the Durie proposal is that those utilising water for commercial purposes should be charged and that an independent commission would be responsible for overseeing charging and revenue collection and disbursement. A proportion of the funds would be allocated to Maori authorities in recognition of the Maori interest. Whether in public or Maori hands, the funds should be applied to the maintenance or improvement of the natural water bodies of the area or the assurance of water supplies to all homes. In short, the proposal focuses upon responsibility.

year: 2019