2,784 research outputs found
Petición del Consulado de Cádiz sobre el pago de alcabalas en Jalapa a fines del siglo XVIII (Los escritos fiscales como fuentes documentales)
Tomo I; pág. 99-11
Electrochemical softening of concentrates from an electrodialysis brackish water desalination plant: Efficiency enhancement using a three-dimensional cathode
The electrochemical softening method to remove hardness from water has not been applied in desalination practice due to a high cathodic area requirement. In this work, the use of a 3D stainless steel wool cathode is proposed to overcome this technical limitation. An extensive comparison between the 3D cathode and a 2D Ti mesh has been presented, showing higher hardness removal for the 3D one. Experiments have been conducted with waters similar to concentrates derived from a brackish water treatment by electrodialysis. In addition, the method has been proved to be efficient for different water compositions in terms of hardness, alkalinity or the presence of an anti-scalant. The main influencing parameters (flow rate and current density) have been studied and it can be concluded that lower flow rates (below 1.2 L h−1) give rise to a better efficiencies and 100 A m−2 is the optimum current density. Moreover, the precipitate was characterised by SEM, EDX and XRD showing that Ca2+ is removed as calcite and aragonite (CaCO3), whereas Mg2+ is precipitated as brucite (Mg(OH)2). Finally, long-term experiments revealed that the 3D stainless steel cathode has a better performance than the 2D Ti mesh, but only at short times
Application of electrodialysis for the treatment of almond industry wastewater
In this work, electrodialysis has been proved to be a suitable technique for decreasing the conductivity of a real wastewater from an almond industry, which has been previously treated by electrocoagulation (EC) and electrooxidation (EO). A seven-cell electrodialyzer, with total active membrane area of 1400 cm2, was employed and several parameters, as the limiting current density, were determined. A method for measuring voltage across the membranes was developed, in order to control membrane fouling. The method consisted of capillaries inserted into the solution compartments and connected to a high impedance voltmeter. A study of the reuse of the concentrate solution was made, and it was stated that it can be concentrated 10 times. The treatment of the wastewater was performed at different voltages (7–16 V) to reach values of conductivity of the diluate of 0.5 mS cm−1. After that, the scaling up to a pre-industrial scale was performed by using a 70-cell electrodialyzer, with total active membrane area of 3.5 m2. The process was performed by applying voltages of 20–70 V and a final conductivity of the diluate of 0.5 mS cm−1 was achieved. The electric energy consumption was calculated in every case
Electrochemical treatment of wastewater from almond industry using DSA-type anodes: direct connection to a PV generator
Food industries such as almond industry generate large volumes of wastewater in their processes and common techniques are not always efficient for treating this kind of effluents. In this work, the feasibility of a treatment for pollutants removal of a real industrial wastewater by electrochemical oxidation s studied at laboratory scale and then scaled-up to pre-industrial scale. The first stage of the work was performed at laboratory scale, using a 63 cm2 cell, where different anodes (Ti/Pt, and DSA anodes (Ti/RuO2 and Ti/IrO2)) and the optimal experimental conditions (pH, current density, temperature and [Cl-]) were studied and established. By using a DSA-Cl2 anode (Ti/RuO2), pH 9, j = 50 mA cm-2, [Cl-] = 2000 mg L-1 and room temperature, chemical oxygen demand (COD) was removed up to 75% and results show that electrooxidation can remove organic pollutants. In the second stage the scaling-up of the process from laboratory to pre-industrial scale was performed, by using a 3300cm2 cell. The electrochemical reactor was finally powered by a photovoltaic generator directly connected, in order to operate by using a renewable energy and a COD elimination of 80% was achieved
Los inmigrantes europeos jubilados en Andalucía: rasgos sociodemográficos, motivaciones para migrar y modo de vida
El objetivo concreto de esta investigación es estudiar el proceso que lleva a los europeos jubilados a residir en la Costa del Sol, sus motivaciones en la toma de decisión, las ventajas e inconvenientes señaladas conforme el tiempo de estancia en España y su edad van avanzando, y su interacción con la sociedad y economía españolas, a través de facetas diversas (vivienda, actividades, redes...), es decir, su modo de vida.Peer reviewe
Kinetic study of pilot-scale supercritical CO2 extraction of rosemary (Rosmarinus officinalis) leaves
NOTICE: This is the author’s version of a work that was accepted for publication in Journal of Supercritical Fluids. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Supercritical Fluids, 55 (2011). http://dx.doi.org/10.1016/j.supflu.2010.09.030Rosmarinus officinalis (rosemary) extracts were obtained in a supercritical pilot-scale plant. Based on experimental information available in the literature for analytical or low-scale processes, extraction temperature and pressure were selected to be 313 K and 30 MPa. At these extraction conditions, the kinetic behavior of the pilot-scale overall
extraction curve were determined with respect to yield, antioxidant activity and carnosic
acid content. The overall extraction curve was represented using Sovova’s model; the
average deviation between measured and calculated yields was lower than 2%. Mass
transfer coefficients in the fluid and solid phases were determined and were compared with previous data reported in the literature for low-scale rosemary supercritical extraction.
A two-stage depressurization procedure was accomplished and the effect of both on-line fractionation and extraction time on the antioxidant activity of the samples collected was studied. The antioxidant activity of the different fractions could be straight correlated with the carnosic acid content with a regression coefficient of 0.92This work has been financed by Universidad Autónoma de Madrid and Comunidad Autónoma de Madrid (ALIBIRD-S2009/AGR-1469) and project FUN-C-FOOD, CSD2007-00063 (CONSOLIDER-INGENIO) from Ministerio de Ciencia e Innovación, Spain
Adolescent Compliance with anti-COVID Measures. Is It Related to Substance Use?
Prevalence rates of compliance with anti-COVID measures have been widely studied, but little is known about this issue in early adolescence. Moreover, the relation between substance use and compliance with anti-COVID regulations is still unexplored. Thus, this study aimed to determine the level of compliance with anti-COVID measures by adolescents and the link between substance use and compliance with anti-COVID regulations. This was a cross-sectional study including 909 participants (Mage = 12.57; SD = 0.81). The most complied measure was mask-wearing, followed by avoiding hug/kiss friends and, finally, social distancing. All substance use negatively correlated with compliance with measures. However, strong alcohol and tobacco were the only substances significantly related to less compliance of anti-COVID measures after controlling for covariates. These results provide evidence about the relation between substance use and compliance with anti-COVID measures. Strategies addressed to decrease substance use could be effective to reduce behaviours associated with coronavirus transmission
Therapeutic opportunities in intestinal microbiota-virus interactions
The host microbiota has emerged a third player in interactions between hosts and viral pathogens. This opens new possibilities to use different tools to modulate the intestinal microbial composition, aimed at reducing the risk of or treating viral enteric infections
The Interactions between host glycobiology, bacterial microbiota, and viruses in the gut
Rotavirus (RV) and norovirus (NoV) are the major etiological agents of viral acute gastroenteritis worldwide. Host genetic factors, the histo-blood group antigens (HBGA), are associated with RV and NoV susceptibility and recent findings additionally point to HBGA as a factor modulating the intestinal microbial composition. In vitro and in vivo experiments in animal models established that the microbiota enhances RV and NoV infection, uncovering a triangular interplay between RV and NoV, host glycobiology, and the intestinal microbiota that ultimately influences viral infectivity. Studies on the microbiota composition in individuals displaying different RV and NoV susceptibilities allowed the identification of potential bacterial biomarkers, although mechanistic data on the virus-host-microbiota relation are still needed. The identification of the bacterial and HBGA interactions that are exploited by RV and NoV would place the intestinal microbiota as a new target for alternative therapies aimed at preventing and treating viral gastroenteritis
A new geometrical method for 3D evaluation of non-rigid registration methods for radiotherapy in prostate cancer
Three-dimensional conformal radiotherapy aims at delivering a high dose of radiation to the tumour, while sparing the surrounding normal tissue to a maximum extent. Image registration is an essential tool for monitoring radiation therapies, since allows morphological comparisons in presence of anatomic variations. The evaluation of non-rigid registration methods is very complicated owe to the absence of a known pointwise correspondence. The use of analysis of variations in target volume delineations has been proposed in the past for the evaluation of non-rigid registration methods. Delineation of the target volume is usually accomplished by outlining the contour of the volume in each separate tomographic slice. In the studies of reference, the 3D surface is rendered from the contours by means of a Delauney triangulation. This geometrical method only works correctly for convex structures. However the volumes involved on pelvic anatomy, such as bladder or prostate including the seminal vesicles, have relevant concavities that introduce a huge error in the evaluation. A new geometrical method for the evaluation of convex-concave target volumes delineation is proposed
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