A contra-rotating marine current turbine has a number of attractive features: near-zero reactive torque on the support structure, near-zero swirl in the wake, and high relative interrotor rotational speeds. Modified blade element modelling theory has been used to design and predict the characteristics of such a turbine, and a model turbine and test rig have been constructed. Tests in a towing tank demonstrated the feasibility of the concept. Power coefficients were very high for such a small model and in excellent agreement with predictions, confirming the accuracy of the computational modelling procedures.High-frequency blade loading data were obtained in the course of the experiments. These show the anticipated dynamic components for a contra-rotating machine. Flow visualisation of the wake verified the lack of swirl behind the turbine. A larger machine is presently under construction for sea trials.

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The Energy Systems Research Unit within the Department of Mechanical Engineering at the University of Strathclyde has developed a novel contra-rotating tidal turbine (CoRMaT). Novel aspects of this turbine include two contra-rotating sets of rotor blades directly driving an open-to-sea permanent magnet generator. The balancing of reactive forces by the use of contra-rotation enables the use of a single point compliant mooring system for station keeping. A series of tank and sea tests have led to the deployment and demonstration of a small stand-alone next generation tidal turbine. The stability of a single-point mooring system is examined and power quality from the direct drive generator is evaluated. It is noted that good stability from a single point mooring can be achieved within a real tidal stream; however from sea testing of the turbine off the west coast of Scotland in the Sound of Islay, it is shown that some instabilities in device station keeping may have an effect on the output electrical power quality. Finally, the scaling up of the power take-off and delivery options for a 250kW production prototype are described and assessed. It was concluded that the most promising option was an enlarged version of the system already tested, namely a direct-drive contra-rotating permanent magnet generator

This survey was designed to determine "standards of excellence" in hospital services as defined by (a) former patients, (b) physicians, (c) hospital employees, and (d) corporate insurance subscribers. One hundred forty-seven (147) patients, 188 employees, and 20 corporate subscribers were interviewed by telephone, and 52 physicians were interviewed in their offices. The interview consisted of a single question: "Can you think of a time when, as a patient/employee/employer/physician, you had a particularly satisfying or dissatisfying experience with a local hospital?" Reported incidents were reviewed, and 239 "critical incidents" were identified. These incidents were classified into 12 descriptive categories relating to the underlying factors in the incident reports. Six focus groups were later held with participants segregated by the population pool they represented. These groups were asked to develop definitions of "excellence" in hospital service quality and standards for service which would "exceed expectations." The focus groups created 122 standards of excellence, which were classified into 43 categories. Overall, the largest percentages of corporate, physician, and employee critical incidents were classified as "Administrative Policy" issues. Patients most often reported "Nurturing" incidents as critical to their perceptions of hospital service quality.