A transient analysis of thermal stresses in ceramic stationary vanes is presented. The application of ceramics to gas turbines represents an alternate approach for designers to increase operating temperatures. Highly dense silicon carbide and silicon nitride vanes are analyzed for application in a heavy duty gas turbine. The most severe thermal loading condition for this turbine is imposed on the vanes. The purpose of this paper is to present the effect of ceramic material, vane size, air foil, cross-sectional geometry, and gas inlet temperature on the thermal response of ceramic vanes.

We present a concept for a wafer-level manufactured photoacoustic transducer, suitable to be used in consumer-grade gas sensors. The transducer consists of an anodically bonded two-layer stack of a blank silicon wafer and an 11 µm membrane, which was wet-etched from a borosilicate wafer. The membrane separates two cavities; one of which was hermetically sealed and filled with CO2 during the anodic bonding and acts as an infrared absorber. The second cavity was designed to be connected to a standard MEMS microphone on PCB-level forming an infrared-sensitive photoacoustic detector. CO2 sensors consisting of the detector and a MEMS infrared emitter were built up and characterized towards their sensitivity and noise levels at six different component distance ranging from 3.0 mm to 15.5 mm. The signal response for the sample with the longest absorption path ranged from a decrease of 8.3% at a CO2 concentration of 9400 ppm to a decrease of 0.8% at a concentration of 560 ppm. A standard deviation of the measured values of 18 ppm was determined when the sensor was exposed to 1000 ppm CO2.

No abstract

No abstract

In More-than-Moore technologies, the number and complexity of micro and nano devices, that are directly integrated into control units of power electronics and mechatronics systems, increase. These systems typically operate at working voltages in the range of 220–1000 VRMS