89 resultados para micro-process-engineering
em University of Queensland eSpace - Australia
Resumo:
It has been argued that beyond software engineering and process engineering, ontological engineering is the third capability needed if successful e-commerce is to be realized. In our experience of building an ontological-based tendering system, we face the problem of building an ontology. In this paper, we demonstrate how to build ontologies in the tendering domain. The ontology life cycle is identified. Extracting concepts from existing resources like on-line catalogs is described. We have reused electronic data interchange (EDI) to build conceptual structures in the tendering domain. An algorithm to extract abstract ontological concepts from these structures is proposed.
Resumo:
This paper considers the question of which is better: the batch or the continuous activated sludge processes? It is an important question because dissension still exists in the wastewater industry as to the relative merits of each of the processes. A review of perceived differences in the processes from the point of view of two related disciplines, process engineering and biotechnology, is presented together with the results of previous comparative studies. These reviews highlight possible areas where more understanding is required. This is provided in the paper by application of the flexibility index to two case studies. The flexibility index is a useful process design tool that measures the ability of the process to cope with long term changes in operation.
Resumo:
Optically transparent, mesostructured titanium dioxide thin films were fabricated using an amphiphilic poly(alkylene oxide) block copolymer template in combination with retarded hydrolysis of a titanium isopropoxide precursor. Prior to calcination, the films displayed a stable hexagonal mesophase and high refractive indices (1.5 to 1.6) relative to mesostructured silica (1.43). After calcination, the hexagonal mesophase was retained with surface areas >300 m2 g-1. The dye Rhodamine 6G (commonly used as a laser dye) was incorporated into the copolymer micelle during the templating process. In this way, novel dye-doped mesostructured titanium dioxide films were synthesised. The copolymer not only directs the film structure, but also provides a solubilizing environment suitable for sustaining a high monomer-to-aggregate ratio at elevated dye concentrations. The dye-doped films displayed optical thresholdlike behaviour characteristic of amplified spontaneous emission. Soft lithography was successfully applied to micropattern the dye-doped films. These results pave the way for the fabrication and demonstration of novel microlaser structures and other active optical structures. This new, high-refractive index, mesostructured, dye-doped material could also find applications in areas such as optical coatings, displays and integrated photonic devices.
Resumo:
Over the past years, component-based software engineering has become an established paradigm in the area of complex software intensive systems. However, many techniques for analyzing these systems for critical properties currently do not make use of the component orientation. In particular, safety analysis of component-based systems is an open field of research. In this chapter we investigate the problems arising and define a set of requirements that apply when adapting the analysis of safety properties to a component-based software engineering process. Based on these requirements some important component-oriented safety evaluation approaches are examined and compared.
Resumo:
Matrix spalling or crushing is one of the important mechanisms of fiber-matrix interaction of fiber reinforced cementitious composites (FRCC). The fiber pullout mechanisms have been extensively studied for an aligned fiber but matrix failure is rarely investigated since it is thought not to be a major affect. However, for an inclined fiber, the matrix failure should not be neglected. Due to the complex process of matrix spalling, experimental investigation and analytical study of this mechanism are rarely found in literature. In this paper, it is assumed that the load transfer is concentrated within the short length of the inclined fiber from the exit point towards anchored end and follows the exponential law. The Mindlin formulation is employed to calculate the 3D stress field. The simulation gives much information about this field. The 3D approximation of the stress state around an inclined fiber helps to qualitatively understand the mechanism of matrix failure. Finally, a spalling criterion is proposed by which matrix spalling occurs only when the stress in a certain volume, rather than the stress at a small point, exceeds the material strength. This implies some local stress redistribution after first yield. The stress redistribution results in more energy input and higher load bearing capacity of the matrix. In accordance with this hypothesis, the evolution of matrix spalling is demonstrated. The accurate prediction of matrix spalling needs the careful determination of the parameters in this model. This is the work of further study. (C) 2002 Elsevier Science Ltd. All rights reserved.
Resumo:
The research was aimed at developing a technology to combine the production of useful microfungi with the treatment of wastewater from food processing. A recycle bioreactor equipped with a micro-screen was developed as a wastewater treatment system on a laboratory scale to contain a Rhizopus culture and maintain its dominance under non-aseptic conditions. Competitive growth of bacteria was observed, but this was minimised by manipulation of the solids retention time and the hydraulic retention time. Removal of about 90% of the waste organic material (as BOD) from the wastewater was achieved simultaneously. Since essentially all fungi are retained behind the 100 mum aperture screen, the solids retention time could be controlled by the rate of harvesting. The hydraulic retention time was employed to control the bacterial growth as the bacteria were washed through the screen at a short HRT. A steady state model was developed to determine these two parameters. This model predicts the effluent quality. Experimental work is still needed to determine the growth characteristics of the selected fungal species under optimum conditions (pH and temperature).
Resumo:
Stem cells, either from embryonic or adult sources, have demonstrated the potential to differentiate into a wide range of tissues depending on culture conditions. This makes them prime candidates for use in tissue engineering applications. Current technology allows us to process biocompatible and biodegradable polymers into three-dimensional (3D) configurations, either as solid porous scaffolds or hydrogels, with controlled macro and/or micro spatial geometry and surface chemistry. Such control provides us with the ability to present highly controlled microenvironments to a chosen cell type. However, the precise microenvironments required for optimal expansion and/or differentiation of stem cells are only now being elucidated, and hence the controlled use of stem cells in tissue engineering remains a very young field. We present here a brief review of the current literature detailing interactions between stem cells and 3D scaffolds of varying morphology and chemical properties, concluding with remaining challenges for those interested in tissue engineering using tailored scaffolds and stem cells.
Resumo:
In this study, we investigate the fabrication of 3D porous poly(lactic-co-glycolic acid) (PLGA) scaffolds using the thermally-induced phase separation technique. The current study focuses on the selection of alternative solvents for this process using a number of criteria, including predicted solubility. toxicity, removability and processability. Solvents were removed via either vacuum freeze-drying or leaching, depending on their physical properties. The residual solvent was tested using gas chromatography-mass spectrometry. A large range of porous, highly interconnected scaffold architectures with tunable pore size and alignment was obtained, including combined macro- and microporous structures and an entirely novel 'porous-fibre' structure. The morphological features of the most promising poly(lactic-co-glycolic acid) scaffolds were analysed via scanning electron microscopy and X-ray micro-computed tomography in both two and three dimensions. The Young's moduli of the scaffolds under conditions of temperature, pH and ionic strength similar to those found in the body were tested and were found to be highly dependent on the architectures.
Resumo:
This paper presents a critical comparison of major changes in engineering education in both Australia and Europe. European engineering programs are currently being reshaped by the Bologna process, representing a move towards quality assurance in higher education and the mutual recognition of degrees among universities across Europe. Engineering education in Australia underwent a transformation after the 1996 review of engineering education1. The paper discusses the recent European developments in order to give up-to-date information on this fast changing and sometimes obscure process. The comparison draws on the implications of the Bologna Process on the German engineering education system as an example. It concludes with issues of particular interest, which can help to inform the international discussion on how to meet today’s challenges for engineering education. These issues include ways of achieving diversityamong engineering programs, means of enabling student and staff mobility, and the preparation of engineering students for professional practic e through engineering education. As a result, the benefits of outcomes based approaches in education are discussed. This leads to an outlook for further research into the broader attributes required by future professional engineers. © 2005, Australasian Association for Engineering Education
Resumo:
The results presented in this report form a part of a larger global study on the major issues in BPM. Only one part of the larger study is reported here, viz. interviews with BPM experts. Interviews of BPM tool vendors together with focus groups involving user organizations, are continuing in parallel and will set the groundwork for the identification of BPM issues on a global scale via a survey (including a Delphi study). Through this multi-method approach, we identify four distinct sets of outcomes. First, as is the focus of this report, we identify the BPM issues as perceived by BPM experts. Second, the research design allows us to gain insight into the opinions of organisations deploying BPM solutions. Third, an understanding of organizations’ misconceptions of BPM technologies, as confronted by BPM tool vendors is obtained. Last, we seek to gain an understanding of BPM issues on a global scale, together with knowledge of matters of concern. This final outcome is aimed to produce an industry driven research agenda which will inform practitioners and in particular, the research community world-wide on issues and challenges that are prevalent or emerging in BPM and related areas.