We present a generic methodology for organic Rankine cycle optimization, where the working fluid is included as an optimization parameter, in order to maximize the net power output of the cycle. The method is applied on two optimization cases with hot fluid inlet temperatures at 120• C and 90• C. Pure fluids and mixtures are compared to see how mixed working fluids affect performance and important design parameters. The results indicate that mixed working fluids can increase the net power output of the cycle, while reducing the pressure levels. The maximum net power output is obtained by fluids with a critical temperature close to half of the hot fluid inlet temperature. For some mixtures we find the maximum net power when the temperature glide of condensation matches the temperature increase of the cooling water, while for other mixtures there are large differences between these two parameters. Ethane is a fluid that obtains a large net power increase when used in mixtures. Compared to pure ethane, an optimized ethane/propane mixture attains a 12.9% net power increase when the hot fluid inlet temperature is 120 • C and a 11.1% net power increase when the hot fluid inlet temperature is 90 • C.

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Along Track Scanning Radiometer (ATSR) data from the ERS 1 satellite mission are used in a global analysis of the surface temperature of the oceans. The data are the low resolution 0.5° by 0.5° average temperatures and cover about 24 months. At global scales a significant seasonal variability is found. On each of the hemispheres the surface temperatures reach their maximum after summer heating. The seasonal sea level variability, as observed from TOPEX/POSEIDON, reaches its maximum 1.1–1.4 months later.

Reliable and eective maintenance support is a vital consideration for the management within today's manufacturing environment. This paper discusses the development of a maintenance system for the world's largest robot welding facility. The development system combines a case-based reasoning approach for diagnosis with context information, as electronic on-line manuals, linked using open hypermedia technology. The work discussed in this paper delivers not only a maintenance system for the robot stations under consideration, but also a design framework for developing maintenance systems for other similar applications. #