Diseño del sistema de control de una planta de residuos térmicos

This article deals with the development of the design of a temperature control system for a vegetable waste treatment plant, specifically the Verilog hardware description language is used on a PSoC CY8-CKIT-059. The system has three stages of information handling, in the first instance the conversion of a decimal voltage value represented by a pulse to bits is performed, then a component in charge of the transformation entered in bits to a new bit sentence that will feed the terminals of different seven-segment displays that make up the graphical interface of the system will be added.Este artículo trata sobre el desarrollo del diseño de un sistema de control de temperatura para una planta de tratamiento de desechos vegetales, específicamente se usa el lenguaje de descripción por hardware Verilog sobre un PSoC CY8-CKIT-059. El sistema cuenta con tres etapas de manejo de información, en primera instancia se realiza la conversión de un valor de tensión decimal representado por un pulso a bits, luego de ello se agregara un componente encargado de la transformación ingresada en bits a una sentencia de bits nueva que alimentara los terminales de distintos displays de siete segmentos que componen la interfaz gráfica del sistema

Luminescent and Scintillating Properties of Lanthanum Fluoride Nanocrystals in Response to Gamma/Neutron Irradiation: Codoping with Ce Activator, Yb Wavelength Shifter, and Gd Neutron Captor

A novel concept for detection and spectroscopy of gamma rays, and detection of thermal neutrons based on codoped lanthanum fluoride nanocrystals containing gadolinium is presented.The trends of colloidal synthesis of the mentioned material, LaF3 co-doped with Ce as the activator, Yb as the wavelength-shifter and Gd as the neutron captor, is reported. Nanocrystals of the mentioned material were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), optical absorption, and photoluminescence spectroscopy. Gamma detection and its potential spectroscopy feature have been confirmed. The neutron detection capability has been confirmed by experiments performed using a 252Cf neutron source.Comment: 5 figures, 16 page

On the activation energy of the formic acid oxidation reaction on platinum electrodes

A temperature dependent study on the formic acid oxidation reaction has been carried out in order to determine the activation energy of this reaction on different platinum single crystal electrodes, namely Pt(1 0 0), Pt(1 1 1), Pt(5 5 4) and Pt(5 4 4) surfaces. The chronoamperometric transients obtained with pulsed voltammetry have been analyzed to determine the current densities through the active intermediate and the CO formation rate. From the temperature dependency of those parameters, the activation energy for the direct reaction and the CO formation step have been calculated. For the active intermediate path, the activation energy are in the range of 50–60 kJ/mol. On the other hand, a large dependence on the electrode potential is found for the activation energy of the CO formation reaction on the Pt(1 0 0) electrode, and the activation energy values for this process range between 20 and 100 kJ/mol. These results have been explained using a reaction mechanism in which the oxidation of formic acid requires the presence of a pre-adsorbed anion on the electrode surface

Effects of the anion adsorption and pH on the formic acid oxidation reaction on Pt(111) electrodes

The effects of solution pH and anion adsorption for the formic acid oxidation reaction on the Pt(111) electrode have been examined using electrochemical techniques. Regarding the pH effects, it has been found that oxidation currents for this reaction increase with pH, which indicates that solution formate is involved in the reaction mechanism. Unexpectedly, the adsorption of sulfate on the Pt(111) electrode has a positive effect on the oxidation of formic acid, which also suggests that adsorbed anions are also involved in the mechanism. The activation energy calculated from temperature dependent measurements diminishes with the solution pH and also in the presence of adsorbed sulfate. These measurements corroborate the involvement of solution formate and anions in the oxidation mechanism. Using these results, a rate equation for the oxidation of formic acid is proposed. The current values calculated from this equation are in very good agreement with the experimental currents in perchloric acid solutions.This work has been financially supported by the MICINN (Spain)(project CTQ2010-16271) and Generalitat Valenciana (project PROMETEO/2009/045, FEDER)

Modelo fenomenológico para la predicción del aceite extraído de Moringa oleífera utilizando un equipo de laboratorio Soxhlet

Moringa oleifera is an oilseed crop with poten­tial for biodiesel production. The second step in this process is the extraction of oil. Extraction in hot water, with a Soxhlet apparatus and the ultrasound technique are the most commonly used methods. The aim of the present work was to obtain a phenomenological model for the Moringa oleifera oil extraction process using Soxhlet. Effective diffusivity for Moringa oil through the kernels is obtained, using the kinetics of the extraction process (experimentally determined) and the Fick’s diffusion second law for non-steady state. The value of 0.685·10-12 m2/s fully matched reports on effective diffusion coefficient for other solids. It was also verified from the statistical analysis and a linear fit for experimental data that the model can be used to describe the oil extraction process of Moringa oleifera in the Soxhlet extractor, responding to the diffusive phenomenon (process controlled by internal resistance).Moringa oleífera es un cultivo oleaginoso con potencial para producir biodiesel. La segunda etapa del proceso es la extracción de aceite. Los métodos más utilizados son la extracción en agua caliente, con Soxhlet y la técnica de ultrasonidos. El objetivo del trabajo fue obtener un modelo fenomenológico para el proceso de extracción de aceite de Moringa oleífera en Soxhlet. Utilizando la cinética del proceso extractivo (determinada experimentalmente) y la segunda ley de difusión de Fick en estado no estacionario, se obtuvo la difusividad efectiva del aceite de Moringa a través de los cotiledones. El valor de 0.685·10-12 m2/s, se corresponde con reportes del coeficiente de difusión efectiva para otros sólidos. Se verificó a partir del análisis estadístico y ajuste lineal de los datos experimentales, que el modelo describe el proceso de extracción de aceite de Moringa oleífera en Soxhlet, respondiendo al fenómeno difusivo (proceso controlado por la resistencia interna)

Sandfly saliva of Lutzomyia ovallesi (Diptera: Psychodidae) as a possible marker for the transmission of Leishmania in Venezuela Andes region

Background & objectives: The saliva of the Phlebotominae is highly immunogenic to the vertebrate host and isa determining factor in the Leishmania infection. The aim of this work was to study the saliva of Lutzomyiaovallesi as a possible risk marker for the transmission of Leishmania.Methods: Two populations of L. ovallesi from different geographical areas and subjected to different environmentalconditions were compared by geometric morphometry of the wings, by protein profile analysis of salivary glandsand by assessing the presence of anti-saliva protein in human sera confronted with laboratory L. ovallesi saliva.Results: The results showed differences in the isometric size and structure of the wings but no allometric effects.Protein profiles of salivary glands of both the L. ovallesi populations studied were found to be similar, based on11 protein bands with molecular weights ranging from 16 to 99 kDa. Anti-saliva antibodies were present inhuman sera, but human sera infected and uninfected with leishmaniasis could not be differentiated.Interpretation & conclusion: We conclude that the saliva of laboratory-reared L. ovallesi is representative ofthat of the wild population. It is suggested to study the presence of anti-saliva antibodies in other species ofsandflies and mosquitoe

Understanding the Effect of the Adatoms in the Formic Acid Oxidation Mechanism on Pt(111) Electrodes

The engineered search for new catalysts requires a deep knowledge about reaction mechanisms. Here, with the support of a combination of computational and experimental results, the oxidation mechanism of formic acid on Pt(111) electrodes modified by adatoms of the p block is elucidated for the first time. DFT calculations reveal that some adatoms, such as Bi and Pb, have positive partial charge when they are adsorbed on the bare surface, whereas others, such as Se and S, remain virtually neutral. When the partial charge is correlated with previously reported experimental results for the formic acid oxidation reaction, it is found that the partial positive charge is directly related to the increase in catalytic activity of the modified surface. Further, it is obtained that such a positive partial charge is directly proportional to the electronegativity difference between the adatom and Pt. Thus, the electronegativity difference can be used as an effective descriptor for the expected electrocatalytic activity. This partial positive charge on the adatom drives the formic acid oxidation reaction, since it favors the formation and adsorption of formate on the adatom. Once adsorbed, the neighboring platinum atoms assist in the C–H bond cleavage. Finally, it is found that most of the steps involved in the proposed oxidation mechanism are barrierless, which implies a significant diminution of the activation barriers in comparison to that of the unmodified Pt(111) electrode. This diminution in the activation barrier has been experimentally corroborated for the Bi–Pt(111) electrode, supporting the proposed mechanism.This work has been financially supported by the MINECO (Spain) (project CTQ2013-44083-P) and Generalitat Valenciana (project PROMETEOII/2014/013)

The role of formic acid/formate equilibria in the oxidation of formic acid on Pt(111)

[EN] The formic acid oxidation reaction has been studied in concentrated perchloric acid solutions (up to 9.14M (60%)) on the Pt (111) surface to explore the relationships between interfacial properties and kinetics. It is found that, as the concentration of perchloric acid in the supporting electrolyte increases, the current markedly decreases, making it possible to detect adsorbed formate on the surface by voltammetric methods. With the aid of DFT calculations, it is shown that the diminution in current is the result of two opposing factors: the reduction in the concentration of free formate in solution and electrode charge effects which encourage the adsorption of formate in a particular configuration. Additionally, the electrochemical behavior under highly acidic conditions suggests the formation of clathrate structures and emphasizes the relevance of the water structure effect in electrode adsorption processes.This work has been financially supported by the Ministerio de Economia, Industria y Competitividad through the project CTQ2016-76221-P. CBR also thanks his Postdoctoral fellowship to Generalitat Valenciana (APOSTD/2017/010).Busó-Rogero, C.; Ferre-Vilaplana, A.; Herrero, E.; Feliu, JM. (2019). The role of formic acid/formate equilibria in the oxidation of formic acid on Pt(111). Electrochemistry Communications. 98:10-14. https://doi.org/10.1016/j.elecom.2018.11.011S10149

Expresión del receptor de andrógenos relativa al receptor de estrógenos (AR/ER) y su correlación con una señal génica de proliferación en cáncer de seno ER-positivo

Objetivo: previamente se reportó que tumores de seno con proporción receptor de andrógenos/receptor de estrógenos ?2 (AR/ER ?2) se asocian con peores pronósticos. De acuerdo con lo anterior, el objetivo del presente estudio fue evaluar la relación entre la proporción AR/ER y una señal génica de proliferación celular en cáncer de seno (CS; también conocido como cáncer de mama) ER positivo (ER+). Métodos: se obtuvieron 1093 muestras de CS primario con datos de expresión génica de la base de datos pública NCI Genomic Data Commons. Se ejecutaron análisis bioinformáticos para establecer niveles de expresión génica de AR y ER, así como de los marcadores de proliferación AURKb, BUB1B, BUB1, CDK1 y CHEK1. Adicionalmente, se definieron subtipos moleculares de CS utilizando el bioclasificador PAM50. Resultados: 835 casos se reportaron como ER+. Entre estos, 58 tumores (7%) presentaron mayores niveles de expresión de AR respecto a ER (AR/ER ?2). En dichos casos se observaron niveles significativamente más altos de proliferación con respecto a tumores, con proporción AR/ER <2 (p = 0,02), y preferencialmente se clasificaron dentro de los subtipos moleculares luminal B y HER2 enriquecido (76,5%). Conclusión: nuestros resultados confirman reportes previos y sugieren que los casos de CS con proporción AR/ER ?2 se asocian con tumores que tienen un comportamiento biológico más agresivo. Asimismo, se refuerza la idea de utilizar inhibidores de AR para el tratamiento de pacientes con CS ER+ que presentan altos niveles de expresión de este tipo de cánce

Co-aggregation ability of cell Wall components of Saccharomyces cerevisiae to pathogenic bacteria

Autoaggregation in bacteria is the phenomenon of aggregation between cells of the same strain, whereas coaggregation is due to aggregation occurring among different species. Aggregation ability of prebiotic bacteria is related to adhesion ability, which is a prerequisite for the colonization and protection of the gastrointestinal tract in all animal species; however, coaggregation ability of prebiotic bacteria offers a possibility of close interaction with pathogenic bacteria