Photoacoustic detection of ammonia exhaled by individuals with chronic kidney disease.

Ammonia (NH) has been reported as a breath biomarker for chronic kidney disease (CKD) usually detected at concentrations greater than 0.25 parts per million by volume (ppmV). NH was detected in breath of individuals with CKD through gaseous photoacoustic spectroscopy (PAS).

Environmental impact of combustion of ethanolic biodiesel/diesel blends from several feedstocks on the gas emission levels in the atmosphere.

The aim of this work was to evaluate simultaneously the effect of produced ethanolic biodiesel from several feedstocks (soybean, crambe, macaw, sunflower, and waste cooking oil) and engine operational conditions (low and high engine speed) during combustion of biodiesel/diesel blends on the NO, NO, NO, CO, and CO emission levels in the atmosphere. The biodiesel samples were prepared in one and/or two reaction steps, according to the acid index of each raw material, by esterification using HSO and/or chemical transesterification using sodium ethoxide, both, through ethanolic route. The quality of the produced biodiesels was confirmed by ASTM/EN specifications.