A Recursive Algorithm for Indoor Positioning Using Pulse-Echo Ultrasonic Signals.

Low frequency ultrasounds in air are widely used for real-time applications in short-range communication systems and environmental monitoring, in both structured and unstructured environments. One of the parameters widely evaluated in pulse-echo ultrasonic measurements is the time of flight (TOF), which can be evaluated with an increased accuracy and complexity by using different techniques. Hereafter, a nonstandard cross-correlation method is investigated for TOF estimations.

An Affordable Fabrication of a Zeolite-Based Capacitor for Gas Sensing.

The development of even more compact, inexpensive, and highly sensitive gas sensors is widespread, even though their performances are still limited and technological improvements are in continuous evolution. Zeolite is a class of material which has received particular attention in different applications due to its interesting adsorption/desorption capabilities. The behavior of a zeolite 4A modified capacitor has been investigated for the adsorption of nitrogen (N), nitric oxide (NO) and 1,1-Difluoroethane (CHF), which are of interest in the field of chemical, biological, radiological, and nuclear threats.