Kistler (Switzerland)

Evidence-based practice (EBP) competency is an expected outcome of baccalaureate education; however, research indicates nursing graduates enter practice with competency gaps. The purpose of this study was to explore the challenges accelerated baccalaureate students experience when learning the steps of EBP. A qualitative, descriptive design was used to identify bottlenecks to student learning. Learning the steps of EBP in an accelerated format was challenging for students. Data analysis revealed 3 types of bottlenecks that stalled learning: cognitive, procedural, and emotional. Faculty build EBP competency by making explicit the steps that help students progress. Scaffolded learning, collaborative partnerships, and reflective practices are recommended to support student learning in accelerated formats.

Pressure and vibration monitoring at high temperatures in harsh environments such as gas turbines, combustion chambers or nuclear power stations are crucial for meeting increased requirements regarding safety, emissions, reliability and cost savings. A new generation of high temperature pressure sensors based on synthetic monocrystalline piezoelectric crystals known under the trade name PiezoStar® offer new perspectives in terms of performance and availability. The crystals have been well proved in numerous applications in harsh environments (such as combustion engines) since many years. Among the outstanding properties of these crystals are their ability to perform continuously at temperatures up to at least 600°C, the absence of pyroelectricity, great stability with no twinning and no phase transition up to the melting point as well as high sensitivity and mechanical strength. Comparisons of critical properties between PiezoStar® crystals and conventional sensing material as well as examples of pressure sensors and accelerometers for high temperature applications are presented.

The operation and emissions of a four cylinder, passenger car common-rail diesel engine operating with two different fuels was investigated on the basis of exhaust stream and in-cylinder soot measurements, as well as a thermodynamic analysis of the combustion process. The two fuels considered were a standard diesel fuel and a synthetic diesel (fuel two) with a lower aromatic content, evaporation temperature, and cetane number than the standard diesel. The exhaust stream soot emissions, measured using an FSN system, as well as a photo-acoustic soot sensor (AVL Micro Soot Sensor), were lower with the second fuel throughout the entire engine operating map. To elucidate the cause of the reduced exhaust stream soot emissions, the in-cylinder soot temperature and KL factor (proportional to concentration) were measured using miniature, three color pyrometers mounted in the glow plug bores. Using the maximum KL factor value to quantify the soot formation process, it was seen that for all operating points, less soot was formed in the combustion chamber using the second fuel. The oxidation of the soot, however, was not strongly influenced by the fuel, as the relative oxidized soot fraction was not significantly different for the two fuels. The reduced soot formation of fuel two was attributed to the lower aromatic content of the fuel. The soot cloud temperatures for operation with the two fuels were not seen differ significantly. Similar correlations between the cylinder-out soot emissions, characterized using the pyrometers, and the exhaust stream soot emissions were seen for both fuels. The combustion process itself, was only seen to differ between the two fuels to a much lesser degree than the soot formation process. The predominant differences were seen as higher maximum fuel conversion rates during premixed combustion at several operating points, when fuel two was used. This was attributed to the lower evaporation temperatures and longer ignition delays (characterized by the lower cetane number) leading to larger premixed combustion fractions.

In the oil logging, automotive and spacecraft industriesthere exists a strong interest in sensing devices which canmeasure a static load with very high resolution at normal andelevated temperatures up to 500 °C. We developed,realized and tested a first- and second-order packaged forcesensor for such requirements. The system consists of a resonantstructure vibrating in its bending mode, which is hermeticallyvacuum packaged in a single-crystal silicon housing together withthe resonance detection sensor. The capacitive detectionelectronics are off-chip, giving a high degree of freedom forthe design and fabrication process. The oscillator operates witha switched lock-in amplifier. The packaged silicon load cellachieved a load sensitivity of 27 Hz N-1, a resolution of2 mN and good repeatability for subsequent load cycles. Theelectronics for the first amplifier stage are mounted togetherwith the silicon load cell in the second level package. Thetemperature limitation caused by the electronics was eliminatedby replacing it with a Fabry-Perot interferometer in thesilicon chip. The optical detection was successfully tested andshowed the resolution of the resonator deflection to be more than tentimes better than the capacitive detector.