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Municipal solid waste combustion (MSWC) plant operators are currently under an increasing pressure to optimize the economic performance of their plants. A route with high potential for optimizing this performance is by improving the performance of the MSWC plant combustion control system, which typically is of the PID-type. In this paper, motivated by the industrial need to improve the overall economic MSWC plant performance, a model based approach is taken to optimize this control system, using recently derived black and white box MSWC plant models. More specific, from a closer analysis of the dynamics of these models a new PID-type of MSWC plant combustion control strategy is derived. It is shown that this new control strategy has improved setpoint tracking properties compared to PID-type of combustion control strategies typically encountered in the industry. As a result, a significant improvement of the economic performance of an MSWC plant will be obtained when replacing such a control strategy for the new one. However, no improvement of the disturbance rejection properties of existing PID-type of combustion control strategies has been observed with the new control strategy, which would also lead to a significant improvement of the economic performance of an MSWC plant, indicating that other, non-PID, types of combustion control strategies are required for that.

Non-destructive testing (NDT) is af name for a range of methods and procedures used to determine fitness of industrial products for further use. The use of NDT testing techniques results in data in the form of signals, images, or sequences of these, which have to be analysed in order to determine if they contain any indications of defects in the inspected objects. This analysis is often quite complex. In the past, systems have been built which used neural networks (and other statistical classifiers) as well as expert systems to interpret NDT data; however, successful uses of these systems in inspection practice are rare. This article presents how the case-based reasoning methodology (where interpretation of new data is based on previous data-interpretation cases) can be used to tackle the problem of NDT data interpretation. The article presents the characteristics of CBR, which make it an interesting alternative to statistical classifiers and to expert systems. Suitability of CBR for NDT data interpretation is illustrated based on examples of two applications: a CBR system for ultrasonic rail inspection and a CBR system for eddy-current inspection of heat exchangers.

The histological response of transmucosal one-stage titanium dental implants coated with hydroxyapatite is described. The gingival adhesion to the implant was examined with regard to coated, partially coated or non-coated surfaces in the cervical region. From each coating type, 9 implants were inserted into dogs. Six months after the insertion, 19 implants could be evaluated, but 8 implants were lost. From these 19 implants, 6 implants showed severe pockets with inflammation up to the bony tissue. The 13 successful implants showed direct bone bonding with the hydroxyapatite coating and adhesion of submucosal connective tissue to the implant surface, with inflammation. The marginal gingiva showed slight inflammation. A totally coated implant will probably introduce inflammation by debris formation against the rough implant surface more easily. The hydroxyapatite coating often disappeared in the soft tissue or in the oral cavity. Bone which directly adapted to the coating seemed to prevent it from resorption.