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Design Space Analysis of the Dual-Active-Bridge Converter for More Electric Aircraft
Full text linkIn the literature, different DC/DC power electronic converters (PECs) have been found to interconnect high-voltage DC and low-voltage DC grids in the electric power distribution networks of aircraft. In this scenario, the dual-active-bridge (DAB) converter has been shown to be one of the most promising topologies. The main disadvantages of this PEC are the large output capacitance required to satisfy more electric aircraft (MEA) requirements and the high conduction losses produced in low-voltage power devices of (LV). Therefore, this paper proposes analytical models to determine the voltage ripple and root-mean-square (RMS) current in DC bus capacitors of DABs considering different modulation strategies. Moreover, an analysis of the design space in an MEA case study is performed to evaluate the influence of the design variables in power losses of power devices and peak-to-peak voltage ripple in DC bus capacitors. These models are useful for the design stage of this PEC, as well as to enable multi-objective optimization procedures by reducing the computational cost of these methodologies. Furthermore, the exploration of the switching frequency and limit of the modulation angle aid in reducing the resulting volume of the low-voltage DC capacitor
Level of Physical Activity, Sedentary Behavior, and Sleep in the Child and Adolescent Population in the Autonomous Community of the Basque Country (6-17 Years Old): Protocol for the Mugikertu Study
Full text linkBackground:
Physical inactivity and sedentary behavior are increasingly common problems in the general population, which can lead to overweight, obesity, diabetes, cardiovascular disease, and decreased motor and cognitive capacity among children and adolescents. Establishing healthy habits in childhood on the basis of the World Health Organization’s 2020 Physical Activity Guidelines is essential for proper physical, motor, and cognitive development.
Objective:
The primary aim of this study is to describe the level of physical activity (PA), sedentary behavior, and sleep of the child and adolescent population from 6 to 17 years of age in the Basque Autonomous Community (BAC). Our secondary aim is to establish a starting point for future research and intervention protocols to improve the existing reality.
Methods:
This cross-sectional study aims to recruit 1111 children and adolescents, aged 6 to 17 years from the BAC in a representative random sample. Participants will wear the ActiGraph WGT3X-BT triaxial accelerometer for 7 consecutive days in their nondominant wrist, and fill out a habit diary log of PA, mobility, and sleep routine. PA intensities, sedentary behavior, and sleep parameters (total bedtime, total sleep time, and sleep efficiency) will be calculated from raw accelerometer data using SPSS (IBM Corp). Participants will be randomly selected.
Results:
The results of this study intend to demonstrate significant differences in PA levels in different age and gender groups since the volume of school PA in the BAC decreases as the age of the schoolchildren increases. The total study sample includes 1111 participants. In April 2021, up to 50% of the sample size was reached, which is expected to increase to 100% by April 2022. This sample will allow us to analyze, discuss, compare, and assess the reality of the school population, in a sensitive period of adherence to behavior patterns, using data from the geographical and administrative area of the BAC. This study will provide a realistic insight into PA levels among children and adolescents in the BAC. It will also offer scientific contributions on the positive relationship between PA levels and sleep quality in this population.
Conclusions:
This study might highlight the need for the promotion of cross-sectional policies so that children and adolescents may increase their levels of PA, thus improving both the school environment and positive healthy behavior
Bateratzen: Enpresa Lehiakorrak eta Pertsona Konprometituak
Full text linkInplikazio handiko antolaketa eredu berrietara igarotzeko gakoak: ikerketan emandako hamarkada baten ikaskuntzak
Ikasgelan elkarrekintza didaktiko emankorrak diseinatzeko tresna baten sorkuntza
Full text linkArtikulu honek ikasgelan elkarrekintza didaktikoak diseinatzeko oinarriak eta balizko
tresna bat eskaintzea du helburu. Erreminta hau irakasleei eskainitako prestakuntza prozesu baten markoan
sortu da eta beraren aplikazioa ikertu ostean, beharrezko izan diren egokitzapenak egin dira, artikulu
honetan aurkezteko. Horrekin batera, diseinu adibide eta testigantza errealak ere jaso dira, tresnaren
erabilpenerako gako batzuk ematen dituztela iritzita. Ardatzean ikasgelako elkarrekintzak jarri dira,
izan ere, ikaslea bere ikaskuntza prozesuaren erdigunean jarriko bada, komunikatzeko eta ezagutzak
elkarrekin eraikitzeko moduak bilatzea garrantzitsua izango da. Beraz, komunikazio testuinguru bakoitzean
hitza nork, noiz, nola eta zertarako erabili jarri da jomugan, eta alderdi horiei erreparatuta ikasleekin
ikaskuntza sakonagoa lortzeko diseinu didaktikoetan lagungarri diren dimentsio batzuk proposatu.The aim of this paper is to offer some basis for the design of didactic interactions, as
well as a specifically created tool for that purpose. That material has been created in the framework
of a teachers’ training process and after analysing its implementation, appropriate changes have been
made to present it in this article. Furthermore, an example of a real didactic design and various testimonies
are also presented, which might be useful for the good practice of the tool already mentioned.
The classroom’s didactic interactions are the main focus of the paper, for the students to be the centre
of their learning process, the key will be to investigate the communication forms and the collective
construction of the knowledge. Hence, the objective is to analyse who, when, how and for what to take
the floor in each communicative context and thereby propose some dimensions that didactic designs focused
on the deep learning of students should have
Double Dead-Time Signal Injection Strategy for Stator Resistance Estimation of Induction Machines
Full text linkA sensorless online temperature estimator is presented in this paper, which estimates the temperature using a novel signal injection strategy. This allows to eliminate the temperature sensors in the machine, as well as their faults, increasing the system reliability. A double dead-time DC signal is injected in the machine, adding a controlled offset in the control drive through the inverter. The proposed strategy eliminates the effect of the dead-time in the injected signal, which is an important drawback in DC injection strategies for resistance estimation. Furthermore, additional hardware is not needed. The strategy has been implemented in an inverter-fed railway traction induction machine. The proposed algorithm has been validated in a real test-bench
Spirituality infrastructure: Notes for Analysing Arantzazu’s Ecosystem
Full text linkThis article sets out to approach spirituality as cultural substratum in the enclave of the Arantzazu Sanctuary (Gipuzkoa, Basque Country) through the counterintuitive notion of infrastructure. Through four vastly different scenes, it aims to illustrate how Arantzazu, as an ecosystem, infrastructures spirituality, exploring this from a historical perspective, as well as looking to its social deployment. In the first scene, the apparition of the Virgin is the precipitating event that enrols an initial group of actors to her flanks. This inaugural event was followed by three others, in which spirituality was to be articulated in different but equally effective ways: the development, in the 1960s, of a laboratory for the production of language and community; the renovation of the basilica and the processes of emptying entailed in the realization of sculptor Jorge Oteiza’s project; and finally, the international mountain marathon Aizkorri-Zegama that takes place in the vicinity of the sanctuary.Este artículo pretende abordar la espiritualidad como sustrato cultural en el enclave del Santuario de Arantzazu (Gipuzkoa, País Vasco) a través de la noción contraintuitiva de infraestructura. Por medio de cuatro enfoques muy diferentes, se pretende ilustrar Arantzazu, como ecosistema e infraestructura de espiritualidad, explorando ésta desde una perspectiva histórica, así como atendiendo a su despliegue social. En el primer enfoque, la aparición de la Virgen es el acontecimiento precipitante que articula a un primer grupo de actores a sus flancos. A este acontecimiento inaugural le siguen otros tres, en los que la espiritualidad se articulará de formas diferentes, pero igualmente eficaces: el desarrollo, en los años sesenta, de un laboratorio de producción de lenguaje y comunidad; la renovación de la basílica y los procesos de vaciado que conlleva la realización del proyecto del escultor Jorge Oteiza; y, por último, la maratón internacional de montaña Aizkorri-Zegama que tiene lugar en las inmediaciones del santuario
CFD Analysis of can Heating Process
Full text linkIn this work, the thermal sterilization process in food cans has been analyzed using Computational Fluid Dynamics (CFD). STAR CCM+ software has been used in order to develop a numerical model to study the heating process of standard and the recently proposed toroidal shaped cans. The model has been validated comparing the results with the ones obtained experimentally and numerically that can be found in the literature. A good
agreement between the obtained numerical results and the experimental ones has been obtained. The results also agree with other numerical models previously developed in the literature. Once the model has been validated, taking advance of the possibility to easily introduce movement in the simulations, new variables have been analyzed in the system using this model, such as rotational movement of the can. The model developed has been used to study the efficiency of the sterilization process with the two types of cans by means of calculating the temperature inside the systems and calculating the F0 parameter. It can be seen that the efficiency of the sterilization process is better in the toroidal cans. It has been also checked that CFD models can be very helpful in analyzing the temperature profiles inside the cans and making sure that the correct temperature has been obtained inside the can and the sterilization process has been correctly carried out
Module-Level Modelling Approach for a Cloudbased Digital Twin Platform for Li-Ion Batteries
Full text linkThe pursue of the new increasingly intelligent, and heavier state estimation algorithms requires a significant amount of data and computing power, which may challenge their deployment in current BMS solutions. To address that issue, this paper proposes a cloud-based Digital Twin Platform to extend computing power and data storage capacity. This tool aims to contain the integration of models to analyse thermoelectricand ageing aspects of a LIB, based on experimental operation data by comparative analysis. Based on well-known cell-level modelling techniques, a module-level modelling approach is proposed and an experimental validation platform is suggested
Employee Perceptions About Participation in Decision-Making in the COVID Era and Its Impact on the Psychological Outcomes: A Case Study of a Cooperative in MONDRAGON (Basque Country, Spain)
Full text linkThis research aims to study possible effects or impacts of COVID-19 in the context of a democratic organizational system analyzing how COVID-19 has influenced employees’ perception of their participation in decision-making and its impact on some psychological outcomes and emotions. COVID-19 has accelerated the process of implementation of new frameworks at work (digitalization, teleworking, new skills, and abilities) that have generated the modification of culture and employee management practices. Our hypothesis are, on the one hand, that COVID-19 has generated changes in participation structures and internal communication mechanisms, having to make modifications not to deteriorate the perception of employees about their participation in decision making. On the other hand, COVID-19 has generated changes in the psychological outcomes and emotions of the employees. In the study, we analyze a cooperative belonging to the MONDRAGON cooperative group, where participation in decision-making and ownership is in its DNA. Through qualitative (5 focus groups) and quantitative (short questionnaire) methodologies, involving 42 employees, we investigate firstly, how COVID-19 has affected perceptions about participation in decision-making analyzing what role has played internal communication in these perceptions. Secondly, we investigate how COVID-19 has affected psychological outcomes and emotions. In this case, the perceptions arising from participation in decision-making focus on the assessment that participators make of the governance channels and the day-to-day meetings. Therefore, their appropriateness seems to be a key factor in the perception of participation in the COVID-19 era. Differences have been detected between the perceptions of blue and white collar employees. Such differences have also been founded in the psychological outcomes and emotions. Although this is a single case study, the analysis carried out provides elements of reflection to modify and restructure the decision-making and participation mechanisms, adapting them to the needs of blue and white collar employees in order to “guarantee” the expected outcomes
Percepción de las familias sobre la diversidad socioeconómica y de origen en su centro escolar. Un estudio cualitativo
Full text linkEl vínculo entre familias y escuela es clave para la construcción de una educación equitativa, inclusiva e intercultural, e influye particularmente en quienes se encuentran en desventaja social. La relación entre las propias familias es un factor importante y complejo en centros con alta diversidad social. El objetivo de este artículo es examinar las percepciones que tienen los padres y madres sobre la diversidad socioeconómica y de origen del centro educativo donde estudian sus hijos e hijas. La investigación se llevó a cabo en una escuela de Gipuzkoa, donde se realizaron once entrevistas en profundidad semiestructuradas a madres y padres de diverso origen y situación socioeconómica. Las entrevistas se grabaron, transcribieron y analizaron mediante el análisis de contenido, utilizando el programa Atlas.ti. Los resultados mostraron una actitud general de aceptación de la diversidad. Sin embargo, los padres y madres autóctonos expresaron determinados estereotipos y desconfianzas hacia las familias inmigrantes. Asimismo, la desventaja económica de algunas familias, la conciencia desigual que existe sobre esa desventaja y las dificultades en su gestión son factores importantes en la relación entre las familias. También lo son los conflictos y desencuentros entre familias autóctonas e inmigrantes. En vista de los resultados, destaca que la falta de comunicación entre las familias reproduce estereotipos y la construcción de un nosotros/ellos. Se concluye que incrementar la conciencia de la desigualdad en la comunidad escolar y actuar sobre las dificultades detectadas puede contribuir a una mejor relación y un clima de centro más inclusivo.The connection between families and school is key to an equitable, inclusive and intercultural education, in particular with regard to those in a more socially disadvantaged situation. The relationships between families themselves is an important and complex element in centers with high social diversity. The aim of this article is to examine the perceptions that parents have about socioeconomic diversity and the variety of family origins in the institutions where their children study. To this end, research was carried out in a school in Gipuzkoa. Eleven semi-structured in-depth interviews were conducted with parents of different origins and socioeconomic bac-kgrounds. The data were recorded, transcribed and analysed performing content analysis by means of the Atlas.ti software. The results showed a general attitude of acceptance towards diversity. However, autochthonous parents adhered to certain stereotypes and expressed distrust towards immigrant families. Likewise, the economic disadvantage of some families, the unequal levels of awareness of such disadvantage, and the difficulties in its management are important factors in the relationships between families. In addition, there are conflicts and disagreements between autochthonous and immigrant families. In view of the results, it seems clear that the lack of communication between families reproduces stereotypes and the construction of a we/they. It is concluded that increasing awareness of inequality in the school community and acting on the difficulties detected may contribute to achieving better relationships and to building a more inclusive school environment