We report the detection of tryptophan at sub-ppb levels for a fluorometer based on Fresnel lenses and low-cost electronics. These fluorometers can be used to detect fecal contamination in drinking water, indicated by tryptophan-like fluorescence.

An operational amplifier based instrumentation amplifier (IA) with a common-mode rejection ratio (CMRR) independent of resistance tolerances is presented in this paper. The CMRR is determined by the operational amplifier characteristics. The IA shows a high CMRR up to 100 kHz. Moreover, since the presented …

A laboratory test setup is built to transfer and actively stabilize an ultrastable signal, obtained from a laser with sub-Hz linewidth, trough a 5 km long fiber link. The fiber noise is measured and compensated via a feedback loop acting on an AOM that can change the frequency (and therefore the phase) …

from the article: The demand for a wireless CO2 solution is ever increasing. One of the biggest problems with the majority of commercial available CO2 sensors is the high energy consumption which makes them unsuitable for battery operation. Possible candidates for CO2 sensing …

From Science direct: One of the nanowires was covered with a 2-Hydroxyethyl methacrylate based compound to prevent hydrogen from reaching the wire. The compound was dried by a UV source and tested in chamber for comparison with previous measurements. The results shows that temperature effects can be …