991 resultados para SIMULATED MOVING-BED


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Experiments were undertaken to study drying kinetics of moist cylindrical shaped food particulates during fluidised bed drying. Cylindrical particles were prepared from Green beans with three different length:diameter ratios, 3:1, 2:1 and 1:1. A batch fluidised bed dryer connected to a heat pump system was used for the experimentation. A Heat pump and fluid bed combination was used to increase overall energy efficiency and achieve higher drying rates. Drying kinetics, were evaluated with non-dimensional moisture at three different drying temperatures of 30, 40 and 50o C. Numerous mathematical models can be used to calculate drying kinetics ranging from analytical models with simplified assumptions to empirical models built by regression using experimental data. Empirical models are commonly used for various food materials due to their simpler approach. However problems in accuracy, limits the applications of empirical models. Some limitations of empirical models could be reduced by using semi-empirical models based on heat and mass transfer of the drying operation. One such method is the quasi-stationary approach. In this study, a modified quasi-stationary approach was used to model drying kinetics of the cylindrical food particles at three drying temperatures.

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This paper presents a database ATP (Alternative Transient Program) simulated waveforms for shunt reactor switching cases with vacuum breakers in motor circuits following interruption of the starting current. The targeted objective is to provide multiple reignition simulated data for diagnostic and prognostic algorithms development, but also to help ATP users with practical study cases and component data compilation for shunt reactor switching. This method can be easily applied with different data for the different dielectric curves of circuit-breakers and networks. This paper presents design details, discusses some of the available cases and the advantages of such simulated data.

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Construction sector policy makers have the opportunity to create improvements and develop economic, social and environmental sustainability through supply chain economics. The idea of the supply chain concept to improve firm behaviour and industry performance is not new. However there has been limited application and little or no measurement to monitor successful implementation. Often purchasing policies have been developed with sound strategic procurement principles but even these have had limited penetration in to the processes and practices of infrastructure agencies. The research reported in this paper documents an action research study currently being undertaken in the Australian construction sector which aims to explore supply chain economic policy implementation for sectoral change by two government agencies. The theory which informs this study is the emerging area of construction supply chain economics. There are five stages to the project including; demand analysis, chain analysis, government agency organizational audit, supplier strategy and strategic alignment. The overall objective is towards the development of a Supplier Group Strategy Map for two public sector agencies. Two construction subsectors are examined in detail; construction and demolition waste and precast concrete. Both of these subsectors are critical to the economic and environmental sustainability performance of the construction sector and the community as a whole in the particular jurisdictions. The local and state government agencies who are at the core of the case studies rely individually on the performance of these sectors. The study is set within the context of a sound state purchasing policy that has however, had limited application by the two agencies. Partial results of the study are presented and early findings indicate that the standard risk versus expenditure procurement model does not capture the complexities of project, owner and government risk considerations. A new model is proposed in this paper, which incorporates the added dimension of time. The research results have numerous stakeholders; they will hold particular value for those interested in regional construction sector economics, government agencies who develop and implement policy and who have a large construction purchasing imprint and the players involved in the two subsectors. Even though this is a study in Australia it has widespread applicability as previous research indicates that procurement reform is of international significance and policy implementation is problematic.

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In recent years concern has been expressed internationally about the future of the library and information services (LIS) profession: recruitment and retention, changing skill sets and declining numbers of people choosing librarianship as a career are all factors contributing to an uncertain future. One area yet explored in any depth is the topic of why LIS studies are not perceived, let alone promoted, as a good first professional qualification for high school graduates. This paper considers the professional literature that examines the uptake of librarianship as a first qualification by school leavers and discusses, in the context of the Australian library sector, the role of professional associations, library schools, National and State Libraries, as well as individual libraries and librarians. Examples of best practice are presented to highlight the opportunities for inspiring and motivating students through well structured and stimulating work experience programs. The topic is relevant to all librarians who are interested in the future of the LIS profession. It is argued that the focus of the present conference on ‘moving up’ and ‘moving on’ can only have real significance when the profession has a more complete understanding of the barriers to and the opportunities for ‘moving in’.

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Rather than passing judgment of the content of young women’s magazines, it will be argued instead that such texts actually exist as manuals of self-formation, manuals which enroll young women to do specific kinds of work on themselves. In doing so, they form an effective link between the governmental imperatives aimed at constructing particular personas – such as the sexually responsible young girl - and the actual practices whereby these imperatives are operationalised.

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In the global knowledge economy, knowledge-intensive industries and knowledge workers are extensively seen as the primary factors to improve the welfare and competitiveness of cities. To attract and retain such industries and workers, cities produce knowledge-based urban development strategies, where such strategising is also an important development mechanism for cities and their economies. This paper investigates Brisbane’s knowledge-based urban development strategies that support generation, attraction, and retention of investment and talent. The paper provides a clear understanding on the policy frameworks, and relevant applications of Brisbane’s knowledge-based urban development experience in becoming a prosperous knowledge city.

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The melting of spherical nanoparticles is considered from the perspective of heat flow in a pure material and as a moving boundary (Stefan) problem. The dependence of the melting temperature on both the size of the particle and the interfacial tension is described by the Gibbs-Thomson effect, and the resulting two-phase model is solved numerically using a front-fixing method. Results show that interfacial tension increases the speed of the melting process, and furthermore, the temperature distribution within the solid core of the particle exhibits behaviour that is qualitatively different to that predicted by the classical models without interfacial tension.

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Aims: This study investigated the effect of simulated visual impairment on the speed and accuracy of performance on a series of commonly used cognitive tests. ----- Methods: Cognitive performance was assessed for 30 young, visually normal subjects (M=22.0yrs ± 3.1 yrs) using the Digit Symbol Substitution Test (DSST), Trail Making Test (TMT) A and B and the Stroop Colour Word Test under three visual conditions: normal vision and two levels of visually degrading filters (VistechTM) administered in a random order. Distance visual acuity and contrast sensitivity were also assessed for each filter condition. ----- Results: The visual filters, which degraded contrast sensitivity to a greater extent than visual acuity, significantly increased the time to complete (p<0.05), but not the number of errors made, on the DSST and the TMT A and B and affected only some components of the Stroop test.----- Conclusions: Reduced contrast sensitivity had a marked effect on the speed but not the accuracy of performance on commonly used cognitive tests, even in young individuals; the implications of these findings are discussed.