No abstract

In the present work, we evaluate a new method for determining a non-perturbed Total Electron Content (TEC) reference to apply on a new version of the disturbance ionosphere index (DIX). This method is based on calculating a 3-hour moving average over the TEC obtained during a given reference day. We compared the proposed method with TEC values obtained from monthly medians and the International Reference Ionosphere (IRI) model to evaluate its performance. The results are presented and discussed in terms of a dispersion coefficient between each method and the averaged TEC from the five quietest days of each month of 2015, over three Brazilian sites. Finally, we calculated the DIX based on the proposed method and compared it with the original DIX values obtained during the St. Patrick's Day magnetic storm (17-18 March 2015). Differences between the two approaches are discussed, and the results showed that the non-perturbed reference determination could highly influence the quality of the DIX calculation.

The quality of wine is checked both during the production process and upon consumption. Therefore, manual wine-tasting work is still valuable. Due to the nature of wine, many volatile components are released, and it is therefore difficult to determine which elements need to be controlled. Acetic acid is one of the substances found in wine and is a crucial substance for wine quality. Gas sensor systems may be a potential alternative for manual wine tasting. In this work, we have developed a TGS2620 gas sensor module to analyze acetic acid levels in red wine. The gas sensor module was refined according to the Venturi effect along with signal slope analysis, providing promising results. The example included in this paper demonstrates that there is a direct relationship between the slope of the MOS gas sensor response and the acetic acid concentration. This relationship is useful to evaluate the ethanol oxidation in acetic acid in red wine during its production process.