Chronopotentiometric study of the transport of phosphoric acid anions through an anion-exchange membrane under different pH values

[EN] Phosphate is the main cause of eutrophication in many water bodies. Its presence in waters is associated to the fact that is not completely removed in conventional wastewater treatment plants. On the other side, phosphate rocks are a non-renewable resource and considered as a critical raw material. A membrane separation process, able to recover phosphate from wastewater, is a promising process to avoid pollution and to reuse phosphate. This paper investigates the transport of salts of phosphoric acid through an anion-exchange membrane (AEM) by means of chronopotentiograms and polarization curves (CVCs). The presence of multiple transition times in the chronopotentiograms and the corresponding limiting current densities in the CVCs indicate a change in the species being transported in the membrane/diffusion boundary layer system, due to the hydrolysis reactions that take place when the concentration polarization is reached. Under the experimental conditions tested, coupled convection (gravitational and elctroconvection) occurs when a certain threshold in the membrane voltage drop is surpassed independently of the electrolyte concentration. However, at high pH values, only one transition time in the chronopotentiograms, due to the transfer of OH- ions with greater concentration and mobility. This fact is reflected in the CVCs by the large plateaus obtained, which hinders the occurrence of coupled convection phenomena, and consequently, water splitting can be considered as the main mechanism responsible for the overlimiting regime.The authors wish to thank the financial support from FINEP, FAPERGS, CAPES and CNPq (Brazil), from the BRICS-STI/CNPq (BRICS STI Framework Programme), from the European Union through the Erasmus Mundus Program (EBW +) and from the CYTED (Network 318RT0551).Gally, C.; García Gabaldón, M.; Ortega Navarro, EM.; Bernardes, A.; Pérez-Herranz, V. (2020). 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Comparison of Local Analysis Strategies for Exudate Detection in Fundus Images

Diabetic Retinopathy (DR) is a severe and widely spread eye disease. Exudates are one of the most prevalent signs during the early stage of DR and an early detection of these lesions is vital to prevent the patient’s blindness. Hence, detection of exudates is an important diagnostic task of DR, in which computer assistance may play a major role. In this paper, a system based on local feature extraction and Support Vector Machine (SVM) classification is used to develop and compare different strategies for automated detection of exudates. The main novelty of this work is allowing the detection of exudates using non-regular regions to perform the local feature extraction. To accomplish this objective, different methods for generating superpixels are applied to the fundus images of E-OPHTA database and texture and morphological features are extracted for each of the resulting regions. 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Vapor-Liquid Equilibria for R-32 and R-410A Mixed With a Polyol Ester: Non-Ideality and Local Composition Modeling

Vapor-liquid equilibria (VLE) data were obtained over a wide range of mixture composition and saturation conditions for difluoromethane (R-32) mixed with a polyol ester oil (POE). These data were correlated using the following local composition models from the literature: Wilson, Heil, Wang and Chao, Tsuboka and Katayama, NRTL, and UNIQUAC. The results were used to evaluate the suitability of these models in predicting the saturation behavior of the R-32/POE mixture. The Heil model had the best performance, with a 2-a error of 4.81 % in predicted saturation pressure; UNIQUAC was the worst, with a 2-a pressure error of more than 12%. Using VLE results from the literature for pentafluoroethane (R-125) mixed with the same oil and model parameters for that mixture, and attempt was undertaken to make a priori predictions of the P-T-x behavior of a blend containing R-32, R-125 and the oil (R-410A/POE). Data were obtained for this blend, and the results indicate that the Heil model can make such predictions with a 2:' a pressure error of about 11 %.Air Conditioning and Refrigeration Project 5

Structure and Decay Correlations of Two-Neutron Systems Beyond the Dripline

The two-neutron unbound systems of 16Be, 13Li, 10He, and 26O have been measured using the Modular Neutron Array (MoNA) and 4 Tm Sweeper magnet setup. The correlations of the 3-body decay for the 16Be and 13Li were extracted and demonstrated a strong correlated enhancement between the two neutrons. The measurement of the 10He ground state resonance from a 14Be(−2p2n) reaction provided insight into previous predictions that wavefunction of the entrance channel, projectile, can influence the observed decay energy spectrum for the unbound system. Lastly, the decay-in-target (DiT) technique was utilized to extract the lifetime of the 26O ground state. The measured lifetime of 4.5+1.1 −1.5 (stat.)±3(sys.) ps provides the first indication of two-neutron radioactivity