Evaluation of water quality and stability in the drinking water distribution network in the Azogues city, Ecuador

This document presents the physical-chemical parameters with the objective of evaluating and analyzing the drinking water quality in the Azogues city applying the water quality index (WQI) and to research the water stability in the distribution network using corrosion indexes. Thirty samples were collected monthly for six months throughout the drinking water distribution network; turbidity, temperature, electric conductivity, pH, total dissolved solids, total hardness, calcium, magnesium, alkalinity, chlorides, nitrates, sulfates and phosphates were determined; the physical-chemical parameters were measured using standard methods. The processed data revealed that the average values ​​of LSI, RSI and PSI were 0.5 (±0.34), 6.76 (±0.6), 6.50 (±0.99) respectively. The WQI calculation indicated that 100% of the samples are considered excellent quality water. According to the Langelier, Ryznar and Pukorius indexes showed that drinking water in Azogues is corrosive. The quality of drinking water according to the WQI is in a good and excellent category.

Electrocatalytic Transformation of Carbon Dioxide into Low Carbon Compounds on Conducting Polymers Derived from Multimetallic Porphyrins

The electrochemical reduction of carbon dioxide is studied herein by using conducting polymers based on metallotetraruthenated porphyrins (MTRPs). The polymers on glassy carbon electrodes were obtained by electropolymerization processes of the monomeric MTRP. The linear sweep voltammetry technique resulted in polymeric films that showed electrocatalytic activity toward carbon dioxide reduction with an onset potential of -0.70 V. The reduction products obtained were hydrogen, formic acid, formaldehyde, and methanol, with a tendency for a high production of methanol with a maximum value of turnover frequency equal to 15.07 when using a zinc(II) polymeric surface. Studies of the morphology (AFM) and electrochemical impedance spectroscopy results provide an adequate background to explain that the electrochemical reduction is governed by the roughness of the polymer, for which the possible mechanism involves a series of one-electron reduction reactions.

Electrocatalytic reduction of carbon dioxide on a cobalt tetrakis(4-aminophenyl)porphyrin modified electrode in BMImBF4

Electro-catalytic reduction of CO₂ at −0.8 V vs. Ag/AgCl has been studied with poly-Co(ii)-porphyrin on ITO in BMImBF₄ as reaction media.

Identification of an IFN-gamma responsive region in an intron of the invariant chain gene

The mechanism by which IFN-gamma up-regulates invariant chain mRNA in antigen-presenting cells has been under intensive investigation. This study shows that in murine monocytic cells the transcriptional up-regulation mediated by the invariant chain (Ii) upstream enhancer only accounts for part of the induction of Ii mRNA by IFN-gamma. We have identified an intronic region in the murine Ii gene that contributes to the transcriptional up-regulation by IFN-gamma. The region has S (H), X/X2 and Y boxes similar to those in MHC class II promoters and the Ii upstream enhancer. Mutations at the putative S, X and Y boxes have abolished the ability of the region to mediate Ii up-regulation by IFN-gamma. Consistent with the functions of these boxes, our findings reveal that the up-regulation of Ii transcription by IFN-gamma mediated by the intronic region is dependent on the induction of class II transactivator by IFN-gamma.