41 resultados para ORIENTED NUCLEATION
Resumo:
The adsorption of water on a model hexagonal surface has been studied using accurate intermolecular potentials. The structure and binding energies of single molecules, clusters, and adlayers are obtained. The limiting case of weak, nondirectional surface-water interactions presented here is compared with other cases involving water-water and water-surface interactions of a similar magnitude (partial templating) and dominating water-surface interactions (perfect templating) from the literature. None of these models is conducive to the nucleation of ice, each for different reasons.Wecommenton the requirements for a good ice-nucleating surface.
Resumo:
We demonstrate the formation of a macroscopically oriented inverse bicontinuous cubic (QII) lipid phase from a sponge (L3) phase by controlled hydration during shear flow. The L3 phase was the monoolein/ butanediol/water system; the addition of water reduces the butanediol concentration, inducing the formation of a diamond (QIID) cubic phase, which is oriented by the shear flow. The phenomenon was reproduced in both capillary and Couette geometries, indicating that this represents a robust general route for the production of highly aligned bulkQII samples, with applications in nanomaterial templating and protein research.
Resumo:
The misuse of Personal Protective Equipment results in health risk among smallholders in developing countries, and education is often proposed to promote safer practices. However, evidence point to limited effects of education. This paper presents a System Dynamics model which allows the identification of risk-minimizing policies for behavioural change. The model is based on the IAC framework and survey data. It represents farmers' decision-making from an agent-oriented standpoint. The most successful intervention strategy was the one which intervened in the long term, targeted key stocks in the systems and was diversified. However, the results suggest that, under these conditions, no policy is able to trigger a self sustaining behavioural change. Two implementation approaches were suggested by experts. One, based on constant social control, corresponds to a change of the current model's parameters. The other, based on participation, would lead farmers to new thinking, i.e. changes in their decision-making structure.
Resumo:
A systematic approach is presented for obtaining cylindrical distribution functions (CDF's) of noncrystalline polymers which have been oriented by extension. The scattering patterns and CDF's are also sharpened by the method proposed by Deas and by Ruland. Data from atactic poly(methyl methacrylate) and polystyrene are analysed by these techniques. The methods could also be usefully applied to liquid crystals.
Resumo:
A procedure is presented for obtaining conformational parameters from oriented but non-crystalline polymers. This is achieved by comparison of the experimental wide angle X-ray scattering with that calculated from models but in such a way that foreknowledge of the orientation distribution function is not required. X-ray scattering intensity values for glassy isotactic poly(methylmethacrylate) are analysed by these techniques. The method could be usefully applied to other oriented molecular systems such as liquid crystalline materials.
Resumo:
Planning is highly conditioned by the relationships between the market, state and politics. This becomes particularly clear in looking at the changes taking place in the countries of the former Communist block as they attempt to establish a new set of relationships. The old power structures have been dislodged and old laws discarded. This paper examines the situation in Bulgaria and explores the preconditions for setting up a new planning system there. The first section outlines the political changes since 1989 and shows how political instability has effected the pace of change. The establishment of a market in land and property is a second precondition for the planning system there and moves in this direction are presented, including restitution policies. Finally the issues raised by the early attempts towards a new planning system are discussed. This paper is the first of a series looking at the countries of Eastern Europe and the author would welcome comments from others working in this field.
Resumo:
One of the primary features of modern government-to-citizen (G2C) service provision is the ability to offer a citizen-centric view of the e-government portal. Life-event approach is one of the most widely adopted paradigms supporting the idea of solving a complex event in a citizen’s life through a single service provision. Several studies have used this approach to design e-government portals. However, they were limited in terms of use and scalability. There were no mechanisms that show how to specify a life-event for structuring public e-services, or how to systematically match life-events with these services taking into consideration the citizen needs. We introduce the NOrm-Based Life-Event (NoBLE) framework for G2C e-service provision with a set of mechanisms as a guide for designing active life-event oriented e-government portals.
Resumo:
With the rapid growth of information and technology, knowledge is a valuable asset in organisation which has become significant as a strategic resource. Many studies have focused on managing knowledge in organisations. In particular, knowledge transfer has become a significant issue concerned with the movement of knowledge across organisational boundaries. It enables the exploitation and application of existing knowledge for other organisations, reducing the time of creating knowledge, and minimising the cost of organisational learning. One way to capture knowledge in a transferrable form is through practice. In this paper, we discuss how organisations can transfer knowledge through practice effectively and propose a model for a semiotic approach to practice-oriented knowledge transfer. In this model, practice is treated as a sign that represents knowledge, and its localisation is analysed as a semiotic process.
Resumo:
Scholars have largely ignored the roles played by government and public sector institutions in the fair trade movement. This article addresses the knowledge gap through examining government involvement in fair trade networks in the context of European devolution and the localization of international development action. Proposing a relational view of fair trade networks, and considering the Fair Trade Nation as a social category for development, it highlights how power sources outside the centralized nation-state permit a political community to associate itself with fair trade. Research from Wales demonstrates that government acts in a leadership role rather than as regulator, conferring political voice and finance while enhancing its international credentials and contributing to the politics of nation-building. Our conclusion is cautious; campaigners celebrate political commitment to fair trade embodied within the category of the Fair Trade Nation, but evidence suggests that government reliance on the market as a vehicle for decentralized development action is limited by how the Fair Trade Nation is currently executed.
Resumo:
Current methods and techniques used in designing organisational performance measurement systems do not consider the multiple aspects of business processes or the semantics of data generated during the lifecycle of a product. In this paper, we propose an organisational performance measurement systems design model that is based on the semantics of an organisation, business process and products lifecycle. Organisational performance measurement is examined from academic and practice disciplines. The multi-discipline approach is used as a research tool to explore the weaknesses of current models that are used to design organisational performance measurement systems. This helped in identifying the gaps in research and practice concerning the issues and challenges in designing information systems for measuring the performance of an organisation. The knowledge sources investigated include on-going and completed research project reports; scientific and management literature; and practitioners’ magazines.
Resumo:
Knowledge is a valuable asset in organisations that has become significant as a strategic resource in the information age. Many studies have focused on managing knowledge in organisations. In particular, knowledge transfer has become a significant issue concerned with the movement of knowledge across organisational boundaries. One way to capture knowledge in a transferrable form is through practice. In this paper, we discuss how organisations can transfer knowledge through practice effectively and propose a model for a semiotic approach to practice-oriented knowledge transfer. In this model, practice is treated as a sign that represents knowledge, and its localisation is analysed as a semiotic process.