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The effect of fuel changes on diesel oxidation catalyst performance was studied by comparing the physical, chemical and biological character of the particulate emissions using three different fuels. Baseline (uncatalyzed) emissions were also compared for these same fuels. The fuels used for this study were: a typical No. 2 fuel, a No. 1 fuel, and a shale oil-derived diesel fuel. Comparisons of NOX, NO, NO2, HC and particulate mass emissions using each fuel were made using selected modes from the EPA 13 mode cycle. Changes in the chemical and biological character of the soluble organic fraction (SOF) were also studied. Fuel properties, most notably fuel sulfur content, were found to affect the performance of the oxidation catalyst used. Fuel sulfur content should be kept as low as possible if catalytic converters are used on diesel powered equipment.

A diesel oxidation catalyst (Engelhard PTX Series) was evaluated on a medium-duty diesel engine (Caterpillar 3208, naturally aspirated, direct injection). Tests were conducted at six modes of the EPA 13 mode heavy-duty cycle to measure the total particulate, soluble organic fraction (SOF), sulfates, NO, NO2, NOx and hydrocarbons emitted by the engine with and without the oxidation catalysts. Chemical analysis of the SOF collected was carried out to determine the effects of the catalysts on each of the subfractions composing the SOF. The Ames Salmonella/microsome bioassay was employed to quantify the mutagenic properties of the particulate SOF. Test results show large increases in the amounts of total particulate and sulfate emissions due to the catalyst while the amounts of SOF are reduced by the catalyst. The amounts of NOx produced with and without the catalyst are similar, but the equivalent NO2 emitted with the catalyst installed is increased at most modes.

The best features of a comb and ring device have been combined to provide an improved micromachined angular rate sensor. The use of differential combs attached to a centrally supported ring gives this electroformed surface micromachine improved signal output and temperature performance. Previous results have been reported for vibratory ring sensors vacuum packaged in solder sealed CERDIPs. Bulk silicon etching and wafer to wafer bonding, used to fabricate millions of pressure sensors and accelerometers each year, have been employed to vacuum package this new CMOS integrated micromachine. Wafer level packaging allows for MEMS chip-scale packaging at the board level. The goal of this project is to develop a low cost sensor capable of reliably functioning at temperatures between -40 °C and 85 °C. The design, modeling, process, package, performance and automotive applications of this sensor will be covered.