CFD-Aspen Plus interconnection method. Improving thermodynamic modelling in computational fluid dynamic simulations

Producción CientíficaThermodynamic modelling in CFD is basically limited to the models available in the simulators. The method presented in this paper connects CFD simulators with Aspen Plus which instantaneously calculates and returns the value of any physical property required. Therefore, all the thermodynamic models and compounds available in Aspen Plus can be implemented in CFD simulations. The connection, created via Matlab and Excel-VBA, has been validated solving two identical CFD simulations first selecting a thermodynamic model available in the simulator and then connecting the simulator with Aspen Plus and selecting the same model. The maximum absolute average deviation between the density and viscosity values obtained in both simulations, for the two case studies analyzed, is lower than 0.7% which demonstrates the proper interconnection. The accuracy of the results obtained modeling multicomponent mixtures and supercritical fluids proves the applicability of the method to any scenarios2018-12-31Ministerio de Economía, Industria y Competitividad - FEDER (Proyects CTQ2013-44143-R and CTQ2016-79777-R

Ultrafast heating by high efficient biomass direct mixing with supercritical water

Producción CientíficaThis work analyzes the influence of the mixer configuration on the mixing efficiency in the process of biomass ultrafast hydrolysis by supercritical water. The results of the CFD simulations of a horizontal tee, a vertical tee and a mixing cross, selected as the optimum mixing configurations, together with the experimental results obtained in our hydrolysis plant, are the base to determine the configuration which provides the best mixing performance. Although slightly higher conversions are obtained in those experiments performed with a horizontal tee, the small differences between the results demand a theoretical analysis. Therefore, according to the CFD simulation results, since the mixing cross provides the best flow distribution and temperature homogenization at the outlet of the mixers and because of the great similarity between the residence time distribution curves of the mixers, the mixing cross is selected as the optimum geometry to perform the mixing.Ministerio de Economía, Industria y Competitividad - FEDER (Projects CTQ2013-44143-R and CTQ2016-79777-R

Energetic metabolism in fasting sheep: regularization of metabolic profile by treatment with oral glucose, with prior handling of gastric groove

The objective of this research was to evaluate a possible corrective measure against negative metabolic states, as occurs in the advanced stage of gestation in ewes, and that sometimes produces a disease called pregnancy toxaemia. In the present research, we found that the joint administration of i.v. lysine-vasopressin (0.08 IU/kg body weight, BW) and an oral glucose solution (50 g) produces an increase in blood glucose, which persists for some time (up to 6 h); therefore, it could be used in the treatment of pregnancy toxaemia. This therapy is based on the fact that lysine-vasopressin induces gastric groove closure in adult ruminants, enabling orally administered glucose to reach the abomasum directly, from where it rapidly passes into the intestine and is immediately absorbed. We can say that the tested treatment causes a significant increase in blood glucose in ewes affected by toxaemia caused by fasting, which, although less marked than conventional therapy with intravenous drip glucose, remains longer, regularizing other parameters indicative of energy metabolism in fasting ewes

Propiedades psicométricas de la versión espanola de la escala de motivación deportiva

This study aimed to analyse the psychometric properties of the Spanish version of the échelle de Motivation dans les Sports (EMS). The sample was made up of 496 athletes: 314 men and 182 women. The confirmatory factorial nalysis confirmed the scales seven-factor structure with method effects, the construct validity was supported by the correlations among the subscales. Furthermore, the results showed satisfactory levels of internal consistency and significant differences between genders were obtained in the end. These results support the use of the Spanish version of the SMS in assessing motivation within the context of sport

Los imponderables de la tecnología educativa en la formación del profesorado

El artículo se focaliza en la influencia que tienen la actitud y los valores culturales y pedagógicos del profesorado ante el uso de los dispositivos tecnológicos en las aulas. La formación del profesorado en tecnología educativa, como valor estratégico relevante, queda orientada en la dirección de promover la innovación y el cambio educativo para la mejora. El análisis llevado a cabo permite identificar hasta cinco principales imponderables de las tecnologías en la formación del profesorado. Se trata de la inestabilidad de los protocolos de equipamiento de los centros escolares, la innovación en los centros escolares versus el desarrollo de artefactos tecnológicos, la gestión y el control como servidumbre, la cultura tecnológica de los centros escolares y los nuevos roles y representaciones entre los agentes educativos. Algunas consideraciones últimas a las que se llega destacan la conveniencia de potenciar en los centros escolares una cultura tecnológica sostenida en actitudes y valores como la libertad, la democracia y el espíritu crítico. Siempre desde la lógica de la reflexión compartida y la cooperación entre los distintos agentes que configuran las comunidades educativas. En el desarrollo de nuestra sociedad del conocimiento se va a precisar, también, de un profesorado adecuada y oportunamente formado en actitudes y valores éticos, pues en el ejercicio de la docencia van a resultar pilares básicos tanto la independencia, como la participación y la configuración de una ciudadanía crítica

Ab initio studies of propene epoxidation on oxidized silver surfaces

Producción CientíficaAb initio density functional simulations have been performed to study the adsorption of propene on partially oxidized silver surfaces and its interaction with surface oxygen. Two different adsorption conformations for propene are studied, with the molecule either intact or forming an Ag–C3H6–O oxymetallacycle (OMC) intermediate. Then, pathways for propene oxide, acrolein and propanone formation have been studied in detail, providing insight into the selectivity of the surfaces. We find that formation of acrolein must necessarily take place from OMC intermediates, requiring at least two neighbouring reactive surface oxygen anions. This suggests a strong relationship between the concentration of surface oxygen and the selectivity of these surfaces.Ministerio de Ciencia e Innovación (Proyect MAT2008-06483-C03-01 and MAT 2011-22781)Junta de Castilla y León (programa de apoyo a proyectos de investigación - Ref. A158A11-

Perfil de personalidad del tenista

El presente trabajo intenta descubrir las características de personalidad del tenista grancanario a partir de la comparación con un grupo de sujetos que practican deportes individuales distintos al tenis y un grupo de sujetos no deportistas. El total de la muestra está constituida por 191 sujetos distribuidos en tres grupos. El grupo de tenistas está formado por 64 sujetos federados en la isla de Gran Canaria, de los cuales 43 son hombres y 21 mujeres; el grupo de deportistas individuales está formado por 63 sujetos, 42 hombres y 21 mujeres y el grupo de no deportistas está formado por 64 sujetos, 41 hombres y 23 mujeres, todos ellos en edades comprendidas entre los 14 y los 25 años de edad. El cuestionario utilizado fue el 16 PF-5 y en el análisis de varianza efectuado se observan tres diferencias significativas en las escalas Apertura-Cambio, Dureza y Manipulación de la imagen. Asimismo, se observan diferencias significativas atendiendo a la variable sexo.The present study sets out to examine the personality characteristics of the Grancanary tennis player through a comparison with a sports group of subjects who practice single sports different from tennis and a non-sports group of subjects. The totality of the sample is composed by 191 subjects separated in three groups. The tennis players group is composed by 64 federated subjects in Gran Canaria island, in which 43 are men and 21 are women; the single sportsmen group is composed by 63 subjects, 42 are men and 21 are women and the non-sports group is composed by 64 subjects, 41 are men and 23 are women, all of them between 14 and 25 years old. The 16 PF-5 was the questionnaire used and the variance analysis shows three meaningful differences: the opening-change, tough-mindedness and impression management scales. In the same way, it is noticed meaningful differences in sex variable

Evaluation of peri-implant soft and hard tissues behavior in screw-retained crowns by the biologically oriented preparation technique (BOPT) : ambispective longitudinal analytical study

Clinical and radiographic evaluation of soft and hard tissues around convergent collar implants and shoulderless abutments. Material and Methods: Ambispective longitudinal analytical study with a sample size of 32 implants in 21 patients t

Soft tissue thickness evaluation in screw-retained crowns by the biologically oriented preparation technique (BOPT)

Intraoral scanner evaluation (3Shape, TRIOS®) of soft tissue thickness around convergent collar implants and shoulderless abutments. Ambispective longitudinal analytical study with a sample size of 26 implants in 17 patients treated in a private denta

Detector de banda ultraancha en tecnología microstrip hasta 40 GHz

Detectors designing is a key aspect for the development of the new millimeter wave systems. In this paper two detectors in microstrip technology are presented. They use zero bias Schottky diodes to detect signals from low frequency to 40 GHz. High sensibility, flat frequency response and ultrabroadband are the main features of these designs. They are also cheap and easy to mount because they have been built using microstrip technology. This paper explains most technological questions which must be taken into account to design such detectors