Armaduras de Acero Inoxidable

En este libro se presentan trabajos de investigación científico-técnica, así como casos prácticos de aplicación de armaduras de acero inoxidable, realizados por grupos de investigación de reconocido prestigio. Los capítulos incluidos en esta obra, son el fruto de los resultados de investigación obtenidos en proyectos competitivos de investigación, tanto fundamental como aplicada. La utilización del acero inoxidable, de los tipos dúplex y austenítico, como refuerzos corrugados en estructuras de hormigón armado, está adquiriendo una gran atención en la actualidad. Esto se justifica debido a la mayor durabilidad de la estructura en servicio, en gran medida debido al mejor comportamiento frente a la corrosión de las armaduras de acero inoxidable. La aplicación del acero inoxidable en estructuras de hormigón armado, presagia un mayor tiempo de vida útil en servicio y por tanto un incremento de las garantías que desde la dirección de construcción de la estructura se pueden ofrecer. Los diferentes estudios realizados de las armaduras de acero inoxidable demuestran un mejor comportamiento frente a la corrosión que las armaduras tradicionalmente utilizadas de acero al carbono (habitualmente B500SD). Además satisfacen los requisitos mecánicos y de resistencia al fuego de forma óptima.Autores: Acosta, P. Matres, V. Alonso, M.C. Medina, E Álvarez, S.M. Múñoz, S Bastidas, D.M. Nóvoa, X. R. Bautista, A. Pachón, A. Belzunce, F. J. Paredes, E. C. Bonaste, V. Peiró, L. M. Fajardo, S. Picón, J. M. Fernández, J. J. Rodríguez, C. Franssen, J. M. Salmerón, A. Fuentes, J. R. Salvador, M. Fullea, J. Sánchez, J.Peer reviewe

El papel facilitador de las TIC en un proceso de aprendizaje colaborativo.

La docencia universitaria no siempre responde a las demandas que la sociedad impondrá a los ahora estudiantes de enseñanza suprior. En numerosas ocasiones el afán por dar respuesta al mayor número posible de contenidos conceptuales hace que se disperse la atnción, tanto de la enseñanza como del aprendizaje, de formas de hacer y actitudes. En el presente artículo exponemos una experiencia de aprendizaje colaborativo que en buena medida trata de paliar estos ʺefectos secundariosʺ, propios de los tradicionales métodos de enseñanza universitaria. Nos centraremos aquí en las innovaciones en las que el docente puede incidir de manera más directa, las relacionadas con el proceso de enseñanza, puesto que sobre los procesos de aprendizaje quien mejor puede hacerlo es el alumnado (Bartolomé, 2004). Desarrollamos la innovación propuesta en la asignatura Organización y Desarrollo de Instituciones Educativas de quinto curso dl plan de estudios de la licenciatura en Psicopedagogía. La citada asignatura representa un claro ejemplo de lo que podría ser una materia teórica dentro de cualquier plan de estudios superiores de nuestro país. Apoyándonos en el aprendizaje por proyectos (Thomas,2000) y en el aprendizaje colaborativo apoyado por ordenador (Computer Supported collaborative learning),(Koschmann,1994) pretendemos generar una dinámica de cambio en el estilo docente, que acerque al alumnado a las tareas que en su futuro profesional deberá asumir, a la vez que facilitamos la adquisición de un amplio abanico de contenidos, necesarios para su formación como psicopedagogos/as. Como discusión final aportamos algunas consecuencias, positivas y negativas, que se desprenden de los procesos formativos de estas características; nos centraremos esencialmente en los perfiles del alumno y del profesorado implicados en procesos de innovación educativotecnológica.University teaching not always responds to the requests that the society will impose to the present‐day students. Nowadays the enthusiasm to give answer to the bigger possible number of conceptual contentses makes that attention scatter of procedures and attitudes. In the present article we display a learning collaborative experience that tries to palliate these side effects of traditional university teaching methods. We develop the innovation proposed in the subject ʺOrganización y Desarrollo de Instituciones Educativaʺ of the fifth course of bachelorʹs degree in Psicopedagogist. Aforementioned subject represents an example of a theoretic matter within any superior curriculum in our country. Starting from the Project Based Lerning methods ( Thomas, 2000 ) and in the Computer Supported collaborative learning ones ,we intend to generate a dynamics of change in the teaching style, to bring near the students to the tasks than in their professional future will have to assume

An anodeless tether generator

A new simple concept for electron collection by an electrodynamic tether is presented. No anodic contactor Is needed, the tether itself, left bare, drawing a current with neither shielding nor magnetic effects. Application to a generator is discussed

An upper atmospheric probe for auroral effects

An electrically floating bare tether in LEO orbit may serve as upper atmospheric probe. Ambient ions bombard the negatively biased tether and liberate secondary electrons, which accelerate through the same voltage to form a magnetically guided planar e-beam resulting in auroral effects at the E-layer. This beam is free from the S/C charging and plasma interaction problems of standard e-beams. The energy flux is weak but varies accross the large beam cross section, allowing continuous observation from the S/C. A brightness scan of line-integrated emissions, that mix emitting altitudes and tether points originating the electrons, is analysed. The tether is magnetically dragged at nighttime operation, when power supply and plasma contactor at the S/C are off for electrical floating; power and contactor are on at daytime for partial current reversal, resulting in thrust. System requirements for keeping average orbital height are discussed

Current-voltage response of a spherical plasma contactor

A theoretical model for a contactor, collecting electrons from an ambient, unmagnetized plasma and emitting a current Iiis discussed. The relation between Ii and the potential bias of the contactor is found to be crucial for the formation of a quasineutral core around the anode and, consequently, for the current colleted. Approximate analytical laws and charts for the current-voltage response are provided

Application of an unsteady flamelet model in a RANS framework for spray A simulation

[EN] In the present investigation the Spray A reference configuration defined in the framework of the Engine Combustion Network (ECN) has been modeled by means of an Unsteady Flamelet Model (USFM) including detailed parametric studies to evaluate the impact of ambient temperature, oxygen concentration and density. The study focuses on the analysis of the spray ignition delay, the flame lift-off length and the internal structure of the spray and flame according to the experimental information nowadays available for validating the results provided by the model. Promising results are obtained for the nominal case and also for the parametric variations (temperature, oxygen...) in terms of liquid and vapor penetration, ignition delay (ID) and lift-off length (LOL). The model permits to predict the ID and the LOL which constitute two parameters of key importance for describing the characteristics of transient reacting sprays. Valuable insight on the details of the combustion process is obtained from the analysis of formaldehyde (CH2O), acetylene (C2H2) and hydroxide (OH) species in spatial coordinates and also in the so-called phi-T maps. Important differences arise in the inner structure of the flame in the quasi-steady regime, which is closely linked to soot formation, when varying the ambient boundary conditions. Additionally, the auto-ignition process is investigated in order to describe in detail the spatial onset and propagation of combustion. Results confirm the impact of the ambient conditions on the regions of the spray where start of combustion takes place, so the relation between the local scalar dissipation rate and mixture fraction variance is also discussed. This investigation provides an insight of the potential of the USFM combustion model to describe the physical and chemical processes involved in transient spray combustion.Authors acknowledge that this work was possible thanks to the Ayuda para la Formacion de Profesorado Universitario (FPU 14/03278) belonging to the Subprogramas de Formacion y de Movilidad del Ministerio de Educacion, Cultura y Deporte from Spain. Also this study was partially funded by the Ministerio de Economia y Competitividad from Spain in the frame of the COMEFF (TRA2014-59483-R) national project.Desantes, J.; García-Oliver, JM.; Novella Rosa, R.; Pérez-Sánchez, EJ. (2017). Application of an unsteady flamelet model in a RANS framework for spray A simulation. Applied Thermal Engineering. 117:50-64. https://doi.org/10.1016/j.applthermaleng.2017.01.101S506411

Influence of the n-dodecane chemical mechanism on the CFD modelling of the diesel-like ECN Spray A flame structure at different ambient conditions

[EN] Encouraged by the diversity of n-dodecane chemical mechanisms currently available, this investigation focuses on analysing the impact of using different fuel oxidation schemes on the diesel-like Engine Combustion Network (ECN) Spray A flame structure, simulated by means of an Unsteady Flamelet Progress Variable (UFPV) combustion model. The present research discusses systematically the characteristics of four n-dodecane chemical mechanisms in perfectly stirred reactors and counterflow laminar diffusion flames (flamelets) before the final evaluation in turbulent reacting sprays in order to describe the effects of adding different physical levels of complexity to the ignition of the mixtures. In addition, this analysis is complemented with the description of the effect of the boundary conditions on the flame structure. Results evidence the extreme importance of the low temperature chemistry including the period for which the cool flame extends. The different prediction of this stage between mechanisms leads to noticeable different laminar flame structures which in turn produce substantially distinct turbulent flames, especially in the vicinity of the lift-off length (LOL) in terms of reactivity and positioning in the Z-T map. Finally, simulations confirm the strong effect of the boundary conditions, especially for the ambient temperature, on the ignitable mixtures which directly impacts on the soot precursors formation. (C) 2019 The Combustion Institute. Published by Elsevier Inc. All rights reserved.Authors acknowledge that this work was possible thanks to the Ayuda para la Formacion de Profesorado Universitario (FPU 14/03278) belonging to the Subprogramas de Formacion y de Movilidad from the Ministerio de Educacion, Cultura y Deporte from Spain. This work was partially funded by the Government of Spain through CHEST Project (TRA2017-89139-C2-1-R).Payri, F.; García-Oliver, JM.; Novella Rosa, R.; Pérez-Sánchez, EJ. (2019). Influence of the n-dodecane chemical mechanism on the CFD modelling of the diesel-like ECN Spray A flame structure at different ambient conditions. Combustion and Flame. 208:198-218. https://doi.org/10.1016/j.combustflame.2019.06.032S19821820

South American Expert Roundtable : increasing adaptive governance capacity for coping with unintended side effects of digital transformation

This paper presents the main messages of a South American expert roundtable (ERT) on the unintended side effects (unseens) of digital transformation. The input of the ERT comprised 39 propositions from 20 experts representing 11 different perspectives. The two-day ERT discussed the main drivers and challenges as well as vulnerabilities or unseens and provided suggestions for: (i) the mechanisms underlying major unseens; (ii) understanding possible ways in which rebound effects of digital transformation may become the subject of overarching research in three main categories of impact: development factors, society, and individuals; and (iii) a set of potential action domains for transdisciplinary follow-up processes, including a case study in Brazil. A content analysis of the propositions and related mechanisms provided insights in the genesis of unseens by identifying 15 interrelated causal mechanisms related to critical issues/concerns. Additionally, a cluster analysis (CLA) was applied to structure the challenges and critical developments in South America. The discussion elaborated the genesis, dynamics, and impacts of (groups of) unseens such as the digital divide (that affects most countries that are not included in the development of digital business, management, production, etc. tools) or the challenge of restructuring small- and medium-sized enterprises (whose service is digitally substituted by digital devices). We identify specific issues and effects (for most South American countries) such as lack of governmental structure, challenging geographical structures (e.g., inclusion in high-performance transmission power), or the digital readiness of (wide parts) of society. One scientific contribution of the paper is related to the presented methodology that provides insights into the phenomena, the causal chains underlying “wanted/positive” and “unwanted/negative” effects, and the processes and mechanisms of societal changes caused by digitalization

Optimal extensions of compactness properties for operators on Banach function spaces

[EN] Compactness type properties for operators acting in Banach function spaces are not always preserved when the operator is extended to a bigger space. Moreover, it is known that there exists a maximal (weakly) compact linear extension of a (weakly) compact operator if and only if its maximal continuous linear extension to its optimal domain is (weakly) compact. We show that the same happens if we consider AM-compactness for the operator, and we give some partial results regarding Dunford-Pettis operators. Narrow operators-considered as a family defined by a weak compactness type property-are also analyzed from this point of view. Finally, we provide some applications of the fact that an operator from a Banach function space extends to a narrow operator if and only if it is narrow. (C) 2015 Elsevier B.V. All rights reserved.J.M. Calabuig and M.A. Juan were supported by Ministerio de Economía y Competitividad (Spain) (project MTM2011-23164). E. Jiménez Fernández was supported by Junta de Andalucía and FEDER grant P09-FQM-4911 (Spain). E. Jiménez Fernández and E.A. Sánchez-Pérez were supported by Ministerio de Economía y Competitividad (Spain) (project MTM2012-36740-C02-02).Calabuig, JM.; Jiménez Fernández, E.; Juan Blanco, MA.; Sánchez Pérez, EA. (2016). Optimal extensions of compactness properties for operators on Banach function spaces. Topology and its Applications. 203:57-66. https://doi.org/10.1016/j.topol.2015.12.075S576620