Development and validation of a one-dimensional solver in a CFD platform for boiling flows in bubbly regimes

This paper presents a new one-dimensional solver for two-phase flow simulations where boiling is involved. The solver has been implemented within the OpenFOAM® platform. The basic formulation follows the Eulerian description of the Navier–Stokes equations. Different closure equations for one-dimensional simulations are also included, as well as a subcooled boiling model in order to perform accurate computations of the mass and heat transfer between phases. In addition to the fluid, a domain is included in order to represent the solid structure, so the solver is able to solve conjugate heat transfer problems. Two different test cases are presented in this work, first a single-phase test case in order to verify the conjugate heat transfer, and then a case based on the Bartolomej international benchmark, which consists of a vertical pipe where the fluid runs upwards while it is heated. Transient calculation were performed, and the results were compared to the TRACE system code, and to the experimental data in the corresponding case. With this calculations, the capability of this new solver to simulate one-dimensional single-phase and two-phase flows including boiling is demonstrated. This work is a first step of a final objective, which consists in allowing a 1D–3D coupling within the CFD platform, avoiding external links

Evaluation of a customer loyalty strategy with system dymamics

The customer loyalty programs are a tool of differentiation and high impact to create long term relationships with customers of a company, so as to achieve an improvement in the portfolio and collections, redu­ced costs of customer service, increased revenue from higher sales to the most profitable customers, cross selling, among many other benefits. Ac­cordingly, we present a system dynamic model to analyze the economic benefits, in terms of profitability, which would be to implement a customer loyalty strategy. To adjust and validate the proposed model, its implemen­tation is done in a real case of a marketer of agricultural products in the department of Valle del Cauca - Colombia. The simulation results show that indeed the model fulfills its purpose, and that the loyalty program achieved significant results in the finances of the organization.Los programas de fidelización de clientes son una herramienta de diferen­ciación y alto impacto para crear relaciones de largo plazo con los clientes de una empresa, de tal forma que se logre una mejora en cartera y recaudo, reducción de costos de atención a clientes, incremento en ingresos por mayores ventas a los clientes más rentables, ventas cruzadas, entre muchos otros beneficios. De acuerdo con esto, se presenta un modelo de dinámica de sistemas que permita analizar los beneficios económicos, en términos de rentabilidad, que se tendrían al implementar una estrategia de fideliza­ción de clientes. Para ajustar y validar el modelo propuesto, se aplica en un caso real de una empresa comercializadora de productos agrícolas de la región. Los resultados de la simulación muestran que efectivamente el modelo cumple con su objetivo, y que el programa de fidelización logra importantes resultados en las finanzas de la organización

Preliminary Results from the Experimental Study of CO2-Brine-Rock Interactions at Elevated T & P: Implications for the Pilot Plant for CO2 Storage in Spain

AbstractA new experimental program has been carried out in order to study CO2-brine-rock interactions susceptible to take place in conditions close to those expected in the pilot plant that is being developed in Spain (a carbonate reservoir located at more than 800 m depth, with 15% porosity, and a salinity of the native brine between 20 – 90g/L). The combination of preliminary experimental and numerical modeling (PHREEQC) results suggests that the main geochemical processes are calcite dissolution and anhydrite precipitation

Development and validation of the scale of psychological abuse in intimate partner violence (EAPA-P)

Background: In the context of intimate partner violence, psychological abuse (PA) has progressively gained scientific relevance. Even so, a greater effort is needed to define and evaluate psychological intimate partner abuse. A new exhaustive and operative taxonomy of PA strategies leads to the contribution of a new evaluation instrument. Method: Participants were 101 women between 24 and 82 years old, who were abused by their partners and attended to in different municipal Catalan services, specialized in the topic. Results: The analyses have shown the suitability of a 19-item instrument divided into two factors: (1) direct PA strategies and (2) indirect PA strategies. The former includes strategies that affect the emotional, cognitive and behavioral dimension of the victim. The latter includes items that measure the amount of control and domination over the victim’s context. This scale has adequate psychometric properties in terms of score reliability and the validity of the relationship with other women’s health variables. Conclusions: The EAPA-P, created based on a new definition and taxonomy of the forms of PA, is presented as a valid instrument to detect and measure intimate partner PA

Cognitive and functional differences in aging with and without intellectual disabilities: Observational study

The lifespan of people with cognitive disabilities (ID) has increased significantly, but the cognitive aspects together with the functional ones comparing normal aging and those with intellectual disabilities had not been previously studied. Objective: This study analyzed the cognitive and functional differences in older adults aging with ID (and with DS), compared with their peers without disabilities, in order to identify the most adapted interventions. Methodology: This study evaluated the outcome variables of MEC, Set-Test, Barthel, Lawton–Brody, and Tinetti with 247 participants: 146 without ID and 101 ID (29 with DS and 72 without DS). Results: At the cognitive level, older people with ID presented lower scores both in MEC (p < 0.01), globally and in each cognitive domain (except in short-term memory), and in verbal fluency (Set-Test) than older people without ID; however, the diagnosis of cognitive impairment and dementia is higher in people without ID. At the functional level, there are no differences in ABDL, but there are in AIDL and Tinetti (p < 0.01), where participants without ID obtain higher scores. The most frequent pathologies in people with ID were obesity and epilepsy. Conclusions: The lower cognitive and functional performance in ID is associated with the disability itself, the low educational level, the neurocognitive underdiagnosis, and the use of poorly adapted assessment tools. The cognitive and functional results indicated the importance of interventions adapted to the characteristics of this population, in their aging process. © 2021 by the author. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)

Gobernanza en Iberoamérica: un reto para su seguridad y soberanía alimentaria

Antecedentes/Objetivos: El discurso político sobre el reto de la desnutrición ha aumentado y llevado a acuerdos nacionales e internacionales. Pero existe un nivel crucial de acción descuidado, centrado en los entornos y procesos que sustentan las políticas y su implementación. Se pretende analizar los factores de la gobernanza que influyen en el impulso de las políticas de nutrición en Iberoamérica, comparándolos con un grupo de países desarrollados, en 2012. Métodos: Estudio transversal ecológico para 2012, que utiliza el país como unidad de análisis (iberoamericanos, Canadá, nórdicos y España) sobre relación entre la gobernanza y 1. Seguridad alimentaria (SeA) y 2. Soberanía alimentaria (SoA). Fuentes información: Estadísticas de Naciones Unidas, Banco Mundial, FAO y UNICEF. Se realizo un modelo de regresión lineal simple, y ajustado por riqueza. Resultados: Controlado por la riqueza del país se detectan asociaciones entre las variables de seguridad alimentaria y soberanía alimentaria con las de gobernanza: La efectividad gubernamental se relaciona con el acceso al agua R2 = 67,4% (p = 0,002), prevalencia de subnutrición R2 = 44,9% (p = 0,02) intensidad déficit alimentario R2 = 51,5% (p = 0,03), desnutrición aguda R2 = 52,1% (p = 0,01). La voz y rendición de cuentas con el acceso al agua R2 = 66,4% (p = 0,003), desnutrición aguda R2 = 49,1% (p = 0,02). El estado de derecho con el acceso al agua R2 = 66,4% (p = 0,003), desnutrición aguda R2 = 51,1% (p = 0,01). El control de la corrupción con el acceso al agua R2 = 71,4% (p = 0,01), desnutrición aguda R2 = 49,8% (p = 0,02). La transparencia con el acceso al agua R2 = 69,5% (p = 0,001), desnutrición aguda R2 = 50,9% (p = 0,01). Y la calidad regulatoria con el acceso al agua R2 = 55,4% (p = 0,05) y desnutrición aguda R2 = 52,9% (p = 0,009). Conclusiones: La efectividad gubernamental es la condición de la gobernanza más ligada a la seguridad y soberanía alimentaria en los países Iberoamericanos. La disponibilidad de agua potable mejorada, se relaciona con todas las categorías de la gobernanza, y la desnutrición aguda con la mayoría. Siendo importante el impulso político para dar respuesta a la población vulnerable necesitada, las intervenciones para fomentar la disponibilidad, utilización y acceso a los alimentos todavía precisan mejorar y evaluar los procesos de toma de decisiones, y los procesos por los que las decisiones son implementadas, o no.Proyecto Prometeo. SENESCYT, Ecuador

On the One-Dimensional Modeling of Vertical Upward Bubbly Flow

[EN] The one-dimensional two-fluid model approach has been traditionally used in thermal-hydraulics codes for the analysis of transients and accidents in water¿cooled nuclear power plants. This paper investigates the performance of RELAP5/MOD3 predicting vertical upward bubbly flow at low velocity conditions. For bubbly flow and vertical pipes, this code applies the drift- velocity approach, showing important discrepancies with the experiments compared. Then, we use a classical formulation of the drag coefficient approach to evaluate the performance of both approaches. This is based on the critical Weber criteria and includes several assumptions for the calculation of the interfacial area and bubble size that are evaluated in this work. A more accurate drag coefficient approach is proposed and implemented in RELAP5/MOD3. Instead of using the Weber criteria, the bubble size distribution is directly considered. This allows the calculation of the interfacial area directly from the definition of Sauter mean diameter of a distribution. The results show that only the proposed approach was able to predict all the flow characteristics, in particular the bubble size and interfacial area concentration. Finally, the computational results are analyzed and validated with cross-section area average measurements of void fraction, dispersed phase velocity, bubble size, and interfacial area concentration.The authors sincerely thank the Plan Nacional de I+D+i for funding the Projects MODEXFLAT ENE2013-48565-C2-1- P, ENE2013-48565-C2-2-P, and NUC-MULTPHYS ENE2012- 34585.Peña-Monferrer, C.; Gómez-Zarzuela, C.; Chiva, S.; Miró Herrero, R.; Verdú Martín, GJ.; Muñoz-Cobo, JL. (2018). On the One-Dimensional Modeling of Vertical Upward Bubbly Flow. Science and Technology of Nuclear Installations. 2018:1-10. https://doi.org/10.1155/2018/2153019S110201

Effects of intensity, attention and medication on auditory-evoked potentials in patients with fibromyalgia

Fibromyalgia (FM) has been associated to an increased processing of somatosensory stimuli, but its generalization to other sensory modalities is under discussion. To clarify this, we studied auditory event-related potentials (AEPs) to stimuli of different intensity in patients with FM and healthy controls (HCs), considering the effects of attention mechanisms and medication. We performed two experiments: In study 1 (n = 50 FM, 60 HCs), the stimuli were presented randomly within the sequence; in study 2 (n = 28 FM, 30 HCs), they were presented in blocks of the same intensity. We analyzed intensity and group effects on N1-P2 amplitude and, only for the FM group, the effect of medication and the correlation between AEPs and clinical variables. Contrary to the expectation, the patients showed a trend of reduced AEPs to the loudest tones (study 1) or no significant differences with the HCs (study 2). Medication with central effects significantly reduced AEPs, while no significant relationships between the N1-P2 amplitude/intensity function and patients' symptoms were observed. The findings do not provide evidence of augmented auditory processing in FM. Nevertheless, given the observed effect of medication, the role of sensory amplification as an underlying pathophysiological mechanism in fibromyalgia cannot be discarded.Spanish Government (Ministerio de ciencia e Innovación; ref PSI2009-14555 and, Ministerio de Economía y Competitividad; ref PSI2013-45818-R) and from the Galician Government (Consellería de Cultura, Educación e Ordenación Universitaria; axudas para a consolidación e Estruturación de unidades de investigación competitivas do Sistema universitario de Galicia; grant number GPC 2014/047). A.G.V. was supported by a grant from the Portuguese Foundation for Science and Technology within the scope of the Individual Call to Scientific Employment Stimulus 2017. N.S.V. was supported by a grant from Spanish Government (Ministerio de Economía y Competitividad; grant number BES-2017-082684

Automated generation of control design benchmark problems for computer-assessed education with Doctus

[ES] En este trabajo se presenta una aplicación que permite a un profesor generar de forma automática ejercicios de diseño de controladores para sistemas lineales para la plataforma de e-learning Doctus. Doctus es una aplicación que permite automatizar la recogida, almacenamiento y evaluación de ejercicios de contenido científico-técnico. En general, para utilizar Doctus es necesario escribir scripts de MATLAB, tanto para la evaluación automàtica de la respuesta de los alumnos como para la generación de enunciados personalizados. La aplicación que se presenta es una extensión de Doctus destinada a simplificar este trabajo, permitiendo generar ejercicios personalizados mediante la aplicación de un escalado temporal y de ganancia a partir de un problema semilla que proporciona el profesor. La aplicación presentada resuelve, por lo tanto, dos problemas: primero el de facilitar el uso de Doctus a profesores no expertos, y segundo el de proporcionar a cada estudiante un ejercicio individualizado[EN] This paper presents an application that enables the teacher to automatically generate control design exercises for linear systems for the Doctus e-learning platform. Doctus is an application that automates the collection, storage and evaluation of scientific and technical education exercises. In general, the use of Doctus requires writing MATLAB scripts, both for the automatic evaluation of student responses and for the generation of personalized wordings. The application presented is an extension of Doctus designed to simplify this work, allowing the generation of personalized exercises by applying time and gain scalings based on a seed problem provided by the teacher. As a consequence, the application presented solves two problems: first, to facilitate the use of Doctus to non-expert teachers, and second, to provide each student with an individualized exercise with guaranteed solution and equal diffculty.Asimismo desean agradecer la ayuda otorgada por el Vicerrectorado de investigación de la Universidad Loyola Andalucía. Este trabajo se ha financiado parcialmente con los proyectos DPI2016-75294-C2-2-R y DPI2016-76493-C3-1-R.Sánchez, C.; Muñoz De La Peña, D.; Gómez-Estern, F. (2020). Generación automática de problemas de diseño de controladores para sistemas lineales autoevaluables con Doctus. Revista Iberoamericana de Automática e Informática industrial. 17(1):1-9. https://doi.org/10.4995/riai.2019.11243OJS19171Ala-Mutka, K. M., 2005. A survey of automated assessment approaches for programming assignments. Computer Science Education 15 (2), 83-102. https://doi.org/10.1080/08993400500150747Ayas, M. S., Altas, I. H., 2016. 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Control automático con herramientas interactivas. Pearson, Inglaterra.Gómez-Estern, F., López-Martínez, M., Muñoz de la Peña, D., 2010. Sistemas de evaluación automática vía web en asignaturas prácticas de ingeniería. Revista Iberoamericana de Automática e Informática Industrial 7 (3), 111-119. https://doi.org/10.4995/RIAI.2010.03.10López-Martínez, M., Gómez-Estern, F., Muñoz de la Peña, D., 2010. Automatic web-based evaluation of C-programming exercises in engineering education. International Journal for Knowledge, Science and Technology 1 (2), 1-6.Martínez, J., Padilla, A., Rodríguez, E., Jiménez, A., Orozco, H., 2017. Diseño de herramientas didácticas enfocadas al aprendizaje de sistemas de control utilizando instrumentación virtual. Revista Iberoamericana de Automática e Informática industrial 14 (4), 424-433. https://doi.org/10.1016/j.riai.2017.03.003Mendez, J. A., Gonzalez, E. J., 2011. Implementing motivational features in reactive blended learning: Application to an introductory control engineering course. IEEE Transactions on Education 54 (4), 619-627. https://doi.org/10.1109/TE.2010.2102028Méndez, J. A., González, E. J., 2013. A control system proposal for engineering education. Computers & Education 68, 266-274. https://doi.org/10.1016/j.compedu.2013.05.014Méndez, J. A., Lorenzo, C., Acosta, L., Torres, S., González, E., 2006. A webbased tool for control engineering teaching. Computer Applications in Engineering Education 14 (3), 178-187. https://doi.org/10.1002/cae.20080Muñoz de la Peña, A., González-Gómez, D., Muñoz de la Peña, D., Gómez-Estern, F., Sánchez, M., 2012a. Automatic web-based grading system: Application in an advanced instrumental analysis chemistry laboratory. Journal of Chemical Education 90, 308-314. https://doi.org/10.1021/ed3000815Muñoz de la Peña, D., Gómez-Estern, F., Dormido, S., 2012b. A new internet tool for automatic evaluation in control, systems and programming. IEEE Computers & Education 59, 535-550. https://doi.org/10.1016/j.compedu.2011.12.016Ogata, K., 2011. Ingenier'ıa de Control Moderna 5ED. Pearson, Inglaterra.Pieterse, V., 2005. Automated assessment of programming assignments. Computer Science Education Research Conference.Prados, F., Boada, I., Soler, J., Poch, J., 2005. Automatic generation and correction of technical exercises. International Conference on Engineering and Computer Education.Ruano Ruano, I., Gámez García, J., Gómez Ortega, J., 2016. Laboratorio web scorm de control pid con integración avanzada. Revista Iberoamericana de Automática e Informática industrial 13 (4), 472-483. https://doi.org/10.1016/j.riai.2016.05.007Sánchez-Alonso, R. E., Ortega-Moody, J., González-Barbosa, J. J., Reyes-Morales, G., 2017. Uso de plataformas para el desarrollo de aplicaciones virtuales en el modelado de robot manipuladores. Revista Iberoamericana de Automática e Informática industrial 14 (3), 279-287. https://doi.org/10.1016/j.riai.2017.04.001Tartaglia, A., Tresso, E., 2002. An automatic evaluation system for technical education at the university level. IEEE Transactions on Education 45 (3), 268-275. https://doi.org/10.1109/TE.2002.1024620Valera, A., Soriano, A., Vallés, M., 2014. Plataformas de bajo coste para la realización de trabajos prácticos de mecatrónica y robótica. Revista Iberoamericana de Automática e Informática industrial 11 (4), 363-376. https://doi.org/10.1016/j.riai.2014.09.00