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Richardson RA Cotton JW Mark Ormerod R 《Dalton transactions (Cambridge, England : 2003)》2004,(19):3110-3115
La(0.6)Sr(0.4)Co(0.2)Fe(0.8)O(3-delta)(LSCF) perovskite powders have been synthesised by solid-state reaction, co-precipitation, drip pyrolysis and citrate gel routes, and characterised using XRF, XRD, SEM and BET. Co-precipitation using oxalic acid or aqueous ammonia as precipitant failed to achieve the correct chemical composition. Perovskite structures were achieved in all other cases. Surface areas ranging from 0.6 to 17.4 m(2) g(-1) were obtained, which was reflected in the different microstructures observed. The citrate gel product exhibited a convoluted network morphology resulting in its large surface area. Thin-walled (approximately 200 microm) tubular membranes have been manufactured from the LSCF powders using viscous plastic processing. The tubes have been characterised using a custom-built gas analysis rig with on-line mass spectrometry. Porosity levels of the membranes were found to be very low (<0.1%). The spontaneous oxygen flux across the tubular membranes was determined as a function of temperature. Oxygen permeation rates ranged from 0.1 to 0.3 micromol cm(-2) s(-1) at 1273 K. The catalytic behaviour of the LSCF tubes towards methane oxidation has been studied using temperature programmed reaction and conventional catalytic measurements. The tubes favoured combustion reactions, with smaller amounts of partial oxidation and oxidative coupling products observed. Powder coatings have been incorporated to establish the effect of increasing surface area. 相似文献
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Richard Ormerod 《The Journal of the Operational Research Society》1996,47(9):1083-1097
The development of an information systems (IS) strategy for a mineral extraction and processing plant operated by Rio Tinto Zinc (RTZ) in South Africa is described. The participative approach used was developed from soft OR and systems thinking. The aim of the Richards Bay project was to test commercially whether the Participative Information Management Strategy (PIMS) methodology could be used as a standard method to be applied to the development of an information systems strategy at any mine site. The paper describes the implementation of the process and the problems encountered. More generally it discusses the diffusion of new ideas in an international company, illustrated by the use of the participative approach for other activities including systems development. Conclusions are drawn about the value of participative approaches based on soft OR in this context. 相似文献
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R J Ormerod 《The Journal of the Operational Research Society》1998,49(4):420-429
The paper reviews the prospects of OR applied by dispersed practitioners, small providers of OR services, academics and OR consultants, in other words OR applied by those not located inside internal OR groups. Many in the UK have regarded the activities of OR groups as the defining practice of our profession. The Survival and Success of OR Groups (SSOR) study indicates that within a fairly stable population of OR practitioners the number of internal OR groups is in decline while the number of external, consulting groups is growing. There are good reasons in terms of the diffusion of innovation for assuming that this trend will continue. Against that possibility, the OR profession in the UK needs to reassess the defining aspects of OR and the implications for the activities of the profession in the future. Using the language of strategy, the profession needs to identify its core competencies, define how they are distinctive, consider how they can be developed and maintained, and determine through which channels they can be delivered. One of the key battlegrounds is within the management consultancies where the competing approaches of management science and organisational development vie for supremacy. 相似文献
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We provide empirical evidence that in a social network which evolves over time, it is possible to extract deep information about the system from limited observations. In this paper, we consider a simple piece of readily available evidence on access to financial services by individuals in the UK. Detailed statistical analysis has shown that the decisions of agents on whether or not to have a basic financial account such as a bank account is heavily influenced by other individuals on their social network. We consider a small amount of straightforward and readily accessible information. We deduce from this, using an agent-based model, the type of social network across which information and influence on behaviour flows between agents in this context. Specifically, we show that information appears to flow across a small world network. 相似文献