Scaleup of wet granulation processes: science not art

Significant advances have been made in the last decade to quantify the process of wet granulation. The attributes of product granules from the granulation process are controlled by a combination of three groups of processes occurring in the granulator: (1) wetting and nucleation, (2) growth and consolidation and (3) breakage and attrition. For the first two of these processes, the key controlling dimensionless groups are defined and regime maps are presented and validated with data from tumbling and mixer granulators. Granulation is an example of particle design. For quantitative analysis, both careful characterisation of the feed formulation and knowledge of operating parameters are required. A key thesis of this paper is that the design, scaleup and operation of granulation processes can now be considered as quantitative engineering rather than a black art. Résumé

Introducing reference semantics via refinement

Two types of semantics have been given to object-oriented formal specification languages. Value semantics denote a class by a set of values representing its objects. Reference semantics denote a class by a set of references, or pointers, to values representing its objects. While adopting the former facilitates formal reasoning, adopting the latter facilitates transformation to object-oriented code. In this paper, we propose a combined approach using value semantics for abstract specification and reasoning, and then refining to a reference semantics before transforming specification to code.

The Politics of Permaculture: Towards an Ecologically Situated Approach to Resource Policy and Governance

The contributions to environmental politics of Torgerson, Oelschlager, Dryzek, Harrè and others, converge in their respective acknowledgements that the shift towards an ‘ecologically situated’ approach to environmental policy, including resource governance, will require the emergence and consolidation of a new lingua franca of environmental discourse. In this paper, I suggest that an extrapolation of permaculture ethics may provide a gambit through which such a discourse may be assembled and organised. I examine six key signifying elements derived from Orr and Capra’s approach to ecological literacy – network, nested system, flow, cycle, development and dynamic balance – and explore the implications that these might have for resource governance and policy, including the (re)framing of assessment indicators, energy auditing, resource management and integrated planning and development.