A chemical sensor for ozone based on an array of microfabricated tuning forks is described. The tuning forks are highly sensitive and stable, with low power consumption and cost. The selective detection is based on the specific reaction of the polymer with ozone. With a mass detection limit of ∼2 pg/mm(2) and response time of 1 second, the sensor coated with a polymer sensing material can detec...

Developing optimal flocking control procedure is an essential problem in mobile sensor networks (MSNs). Furthermore, finding the parameters such that the sensors can reach to the target in an appropriate time is an important issue. This paper offers an optimization approach based on metaheuristic methods for flocking control in MSNs to follow a target. We develop a non-differentiable optimizati...

In the domain of ubiquitous computing, the ability to identify the occurrence of situations is a core function of being 'contextaware'. Given the uncertain nature of sensor information and inference rules, reasoning techniques that cater for uncertainty hold promise for enabling the inference process. In our work, we apply the Dempster Shafer theory of evidence to determine situation occurrence...

Diesel engines, generating harmful NOx, will be subjected to legislation that stipulates large reductions in emission levels beginning in 2007. For controlling emissions, a NOx sensor is needed to provide feedback to the engine management system. In this work, we take advantage of the high mass sensitivity of resonant sensors and the chemical reaction of barium carbonate (BaCO3) with NO2 gas as...

In this study, electron beam lithography, rather than the most popular method, chemical synthesis, is used to construct periodical TiO(2) nanowires for a gas sensor with both robust and rapid performance. The effects of temperature on the sensing response and reaction time are analyzed at various operation temperatures ranging from 200 to 350 °C. At the optimized temperature of 300 °C, the pro...

Because of legislative regulations like OBDII, on-board diagnosis has gained much interest lately. A model based approach is suggested for the diagnosis of the air intake system of an SI-engine. Important research issues are modeling concepts, residual generation and evaluation, overall performance, and limiting factors. The diagnosis system is based on a non-linear semi-physical model and uses...

The electrochemical sensor for detecting hydrogen sulfide was fabricated. H2S gas molecules pass through polytetrafluoroethylene membrane with 0.22 mm pore size. Carboxylated multi-walled carbon nanotubes (MWCNTs-COOH) were used to fabricate working and counter electrodes. It can be seen from Field Emission Scanning Electron Microscopy (FESEM) images of the working electrode that...

A prototype sun sensor has been developed. It consists of a thin slice of silicon coated with a layer of chrome and a layer of gold with hundreds of small pinholes, placed on top of an Active Pixel Sensor (APS) image detector at a distance of 500 microns. Images of the sun are formed on the APS image detector when the sun illuminates the mask. Image processing of the Sun image is performed exte...

Miniaturization and integration of chemical devices into modules that are dimensionally comparable with electronic chips (Lab on Chip) is nowadays developing worldwide. The aim of our work was to suggest and optimize the best conditions for fabrication of TFT sensor due to its sensitivity and low experimental deviations. New electrochemical analytical device was developed to ensure certain know...

we report the development of different types of oxygen sensors based on yittria-stabilized zirconia (ysz) as a solid electrolyte. the conventional oxygen sensor is a concentration cell with two porous pt electrodes, one of which is exposed to air as a constant (reference) oxygen concentration and the other is exposed to automobile exhaust gas of variable oxygen concentration, depending on the a...