Hybrid power-heat microgrid solution using hydrogen as an energy vector for residential houses in Spain. A case study

In order to favor a transition to a renewable energy economy, it is necessary to study the possible permeation of renewable energy sources not only in the electric grid or industrial scale, but also in the small householding scale. One of the most interesting technologies available for this purpose is solar energy, since it is a mature technology that can be easily installed in every rooftop. Thus, a techno-economic assessment was carried out to evaluate the installation of a solar-based power-heat hybrid microgrid considering the use of hydrogen as an energy vector in a typical residential house in Spain. Lead-acid batteries plus the photovoltaic and solar thermal energy installation are complemented with a hydrogen system composed of an electrolyzer, two metal hydride bottles, and a fuel cell. A simulation tool has been generated using experimental models developed and validated with real equipment for each one of the electric microgrid component. Three operating modes were tested making use of this tool to better manage the energy consumed/produced and optimize the economic output of the facility. The results show that setting up a hydrogen-based microgrid in a residential house is unviable today, mainly due to the high cost of hydrogen generation and consumption equipment. If only solar energy is considered, the microgrid inversion (12.500 €) is recovered in ten years. On the other hand, selling the electricity output has almost no repercussions considering current electrical rates in Spain. Finally, while using an optimization algorithm to manage energy use, battery life-spam, and economic benefit slightly increase. However, this profit may not be enough to justify the use of a more complex control system. The results of this research will help users, renewable energy companies, investigators, and policymakers to better understand the different factors influencing the spread of renewable smart grids in households and propose solutions to address these.Junta de Andalucía - Consejería de Conocimiento, Investigación y Universidad PY18-RE-002

Fatiga digital en estudiantes universitarios como consecuencia de la enseñanza online durante la pandemia Covid-19

The continued use of videoconferencing systems to carry out the teaching-learning process in higher education institutions during the Covid-19 pandemic has had a negative impact on university students' learning, causing digital fatigue. This fatigue mainly affects eyesight, emotional, motivational and social status. The aim of this study was to determine the degree of digital fatigue derived from prolonged exposure to videoconferencing systems among university students. For this purpose, a cross-sectional study design was applied based on the distribution of an online survey. A total of 613 university students aged 18-35 years (M = 21.54, SD = 3.85) participated in the study. The results obtained revealed that: 1) the degree of prevalence of digital fatigue among university students was medium-high; 2) socio-demographic variables linked to being female, studying in the Arts and Humanities, spending more time in front of an electronic device and connecting via a laptop were indicators of a higher rate of digital fatigue; 3) gender and high hours consumption were predictors of visual fatigue, social fatigue, motivational fatigue and emotional fatigue; 4) visual fatigue, motivational fatigue and emotional fatigue, together with the field of study knowledge, had a significant influence on overall fatigue. Finally, the future lines of research of this work are discussed, highlighting the richness of the data obtained to advance knowledge about digital fatigue and its influence on university learning.El uso continuo de los sistemas de videoconferencia para llevar a cabo el proceso de enseñanza-aprendizaje en las instituciones de educación superior, durante la pandemia derivada de la Covid-19, ha influido negativamente en el aprendizaje de los estudiantes universitarios, provocando fatiga digital. Esta fatiga afecta principalmente a la vista, estado emocional, motivacional y social. El objetivo de este trabajo fue determinar el grado de fatiga digital derivada de la exposición prolongada a sistemas de videoconferencia de los estudiantes universitarios. Para ello, se aplicó un diseño de estudio transversal a partir de la distribución de una encuesta en línea. En el estudio participaron un total de 613 estudiantes universitarios, con edades comprendidas entre los 18 y 35 años (M = 21,54; DT = 3,85). Los resultados obtenidos revelaron que: 1) el grado de prevalencia de la fatiga digital en los estudiantes universitarios fue medio-alto; 2) las variables sociodemográficas vinculadas a ser mujer, cursar estudios de la rama de Artes y Humanidades, pasar más tiempo frente a un dispositivo electrónico y conectarse a través de un ordenador portátil fueron indicadores de una mayor tasa de fatiga digital; 3) el sexo y el consumo elevado de horas fueron variables predictores de la fatiga visual, fatiga social, fatiga motivacional y fatiga emocional; 4) la fatiga visual, fatiga motivacional y fatiga emocional, junto a la rama de conocimiento de los estudios cursados, influyeron de forma significativa en la fatiga general. Finalmente, se discuten las futuras líneas de investigación de este trabajo, destacando la riqueza de los datos obtenidos para avanzar en el conocimiento sobre la fatiga digital y su influencia en el aprendizaje universitario

ESTUDIO SOBRE EL JUEGO EN EL AULA: PROPUESTA PARA MEJORAR LA ENSEÑANZA DE LAS CIENCIAS SOCIALES EN EDUCACIÓN PRIMARIA

INTRODUCTION. Teachers frequently find a lot of difficulties when it comes to teaching Social Sciences at Primary School due to its contents. So, pupils’ motivation tends to be very low in most cases. When pupils come across new challenges derived from the subject, they may pay less attention and they might not study as a consequence. Everybody knows that children love playing; regardless of the type of game it is proposed. In consequence, games will be implemented in the classroom in order to test the role that games can play in pupils’ motivation. METHOD. To begin with, some Primary School teachers have been interviewed to know what they think about using games in the Social Sciences classroom. Next, pupils’ behaviour and their degree of commitment have been registered in some classrooms where games have not been used as a teaching technique. After that, some games related to the contents of the subject have been designed and later implemented in the classroom. Then, pupils’ behaviour and their degree of commitment have been registered in those classrooms where games have been implemented. Finally, results have been compared, paying special attention to conflictive students. RESULTS. It must be noted that pupils’ motivation grows dramatically in those sessions where games have been used. Furthermore, the disturbance of the normal rhythm in class by those students considered as conflictive is considerably diminished. DISCUSSION. Traditional methodologies are still used in Social Sciences teaching despite pupils’ motivation improvement when games are implemented as a teaching technique

Competencias gerenciales de los administradores de empresas en Bucaramanga y su área metropolitana (Colombia) [Management skills for managers of companies in Bucaramanga and its metropolitan area (Colombia)]

Resumen: En la resolución Nº 2767 del Ministerio de Educación de Colombia (MEN) se definen las características específicas de calidad para los programas de pregrado en Administración de empresas (AEs), con un diseño curricular basado en competencias. A pesar de elementos comunes en los diseños curriculares de las IES, hay diferencias en estrategias pedagógicas y administrativas, debido a recursos disponibles y a la orientación académica. Se tomó como caso representativo el programa de Administración de Empresas de las Unidades Tecnológicas de Santander (UTS). Para la recolección de datos, se aplicó una encuesta a empresarios con el fin de identificar las competencias del deber ser de un gerente en el contexto de las pequeñas y medianas empresas de la región, así como egresados con el objetivo de determinar el nivel el programa de AEs. Se estableció el alcance del currículo de AEs en UTS y su pertinencia en contexto empresarial de la región.Palabras clave: competencias gerenciales, administración de empresas, pequeñas y medianas empresas. Abstract:In Resolution No. 2767 of the Ministry of Education of Colombia specific quality characteristics are defined for undergraduate programs in Business Administration (AEs), with a competency-based curriculum design. Despite common elements in the curricula of higher education institutions, there are differences in educational and administrative strategies, because resources and academic orientation. Program Business Administration Technology unit of Santander (UTS) was taken as a representative case. To collect data, a survey of employers in order to identify the competencies of a manager must be in the context of small and medium enterprises in the region and graduates applied in order to determine the level the program of AEs. The scope of the curriculum of AEs in UTS and its relevance to business context of the region was established.Keywords: skills, business administration, small and medium-size enterprises

Effect of the Gas Diffusion Layer Design on the Water Management and Cell Performance of a PEM Fuel Cell

The influence of the different properties of the gas diffusion layer (GDL) on the operation of a liquid-cooled, proton-exchange polymer electrolyte fuel cell (PEMFC) has been studied in this work. Three-dimensional numerical simulations (CFD) have been conducted to compare several commercial GDLs with different properties, analyzing their influence on the cell performance. Specifically, four GDLs (AvCarb P-75, SIGRACET 34BC, SIGRACET 34BA and Toray TGP-H-090) have been studied, two of them including a microporous layer (MPL). The effect of the MPL has been inspected by contrast of the results obtained with the same GDL, with or without MPL. Potentiostatic boundary conditions have been applied, varying the electric potential between 1.05 and 0.35 V to obtain a representative i−V curve with enough resolution. Detailed postprocessing tasks were carried out to gain a deeper understanding on the phenomena occurring within the cell for each GDL. It can be concluded from this work that a high electrical conductivity and a high permeability lead to a better fuel cell performance. On the other hand, although the presence of MPL provides lower permeability leading to a worse overall performance, it has been shown that the lack of it may result in membrane dehydration and cell degradation issues.Junta de Andalucía / FEDER - PAIDI 202

Renewable medium-small projects in Spain: Past and present of microgrid development

This paper reviews the on-going research studies and microgrid pilot projects focusing on the Spanish case because of its renewable energy potential with the objective set on highlights the main investigation drifts in the field such as the used technologies, control methods and operation challenges. That way, several smart grids have been commented and compared, finding that photovoltaic and wind power are the favourites energy generation technologies. Although batteries are the most widespread energy storage systems, green hydrogen has a strong presence, showing up in a third of the Spanish smart grids. Traditional control strategies are being displaced by advanced ones such as MPC or fuzzy logic due to its higher efficiency. The reader will have a clear view of the potential of renewable energy penetration in the form of smart grids in Spain, through the study of the equipment involved in the different facilities contribution and the main control strategies implemented, in a comparative analysis of the key aspect of this emerging technology.Consejería de Conocimiento, Investigación y Universidad - Junta de Andalucía PY18-RE-002

Advances in the Decision Making for Treatments of Chronic Patients Using Fuzzy Logic and Data Mining Techniques

Virological events in HIV-infected patients can rise with no apparent reason. Therefore, when they appear, immunologists or medical doctors do not know whether they will produce other future virological events or they will entail relevant clinical consequences. This paper presents the results of applying Prefurge to HIV- infected patients’ clinical data, with the aim of obtaining rules and information about this set of clinical trials data that will relate these kinds of virological events.Junta de Andalucía TIC-578

Hydrogen as energy storage for wind energy

Nowadays, problems associated with greenhouse gases emission and fuel ending, makes that renewable energy sources and hydrogen technology have high interest for governments and researchers, and become an option for an environmentaly sustainable world. Renewable energy sources, like solar energy and wind energy, have been used for the last three decades to produce electricity. Researchers and companies have improved the efficiency of this kind of systems, but they have a problem due to energy source temporality that does a fluctuation in systems power output. This fluctuation makes sometimes energy demand is higher than energy produced by the system and vice versa. Hydrogen Technology, actuating as energy storage, may solve this problem. In this paper, a wind-hydrogen installation will be described. Also, its behavior in relation to different electric demand will be analysed