Effects of wet/dry-cycling and plasma treatments on the properties of flax nonwovens intended for composite reinforcing

Producción CientíficaThis research analyzes the effects of different treatments on flax nonwoven (NW) fabrics which are intended for composite reinforcement. The treatments applied were of two different kinds: a wet/dry cycling which helps to stabilize the cellulosic fibers against humidity changes and plasma treatments with air, argon and ethylene gases considering different conditions and combinations, which produce variation on the chemical surface composition of the NWs. The resulting changes in the chemical surface composition, wetting properties, thermal stability and mechanical properties were determined. Variations in surface morphology could be observed by scanning electron microscopy (SEM). The results of the X-ray photoelectron spectroscopy (XPS) showed significant changes to the surface chemistry for the samples treated with argon or air (with more content on polar groups on the surface) and ethylene plasma (with less content of polar groups). Although only slight differences were found in moisture regain and water retention values (WRV), significant changes were found on the contact angle values, thus revealing hydrophilicity for the air-treated and argon-treated samples and hydrophobicity for the ethylene-treated ones. Moreover, for some of the treatments the mechanical testing revealed an increase of the NW breaking force.Ministerio de Educación y Formación Profesional (grants BIA2014-59399-R and FPU12/05869

Palimpsestos mexicanos

[ES] Palimpsestos mexicanos surgió tras la obtención de la beca Santander con destino en la Facultad de Arte y Diseño, UNAM, CDMX, México. La propuesta se concibe como un proyecto expositivo multidisciplinar constituido por un conjunto de subproyectos heterogéneos, en sinergia, uniendo fuerzas, realizados con disciplinas y técnicas diversas tales como el collage, la gráfica y la escultura. El planteamiento general de la obra gira alrededor de las problemáticas que afronta la sociedad mexicana: la corrupción política, las grandes desigualdades sociales, el crimen organizado, la discriminación que sufren los pueblos indígenas, la situación de indefensión de la mujer ante un entorno preeminentemente machista y los intolerables índices de feminicidios. En definitiva, un conjunto de factores que desestabilizan el país y crean inseguridad en la población. Palimpsestos mexicanos también visibiliza la lucha por los derechos civiles de los sectores más desfavorecidos de la sociedad, y empodera y convierte a la mujer mexicana en símbolo de esperanza de un futuro mejor. Proponiendo un dibujo de México alejado de los estereotipos y del folclorismo que presuntamente define su identidad nacional. Aportando una visión del país diferente al imaginario conocido, desde un punto de vista subjetivo, de carácter político pero no dogmático. Con la intención de mostrar, a través del arte contemporáneo, un México en construcción con unas problemáticas a resolver de dimensiones estratosféricas y fascinante en sus retos de futuro. En un país, el más poblado de habla hispana, que está llamado a ser una potencia económica y un referente cultural a escala global.[EN] Mexican Palimpsests emerged after obtaining the Santander scholarship in the Faculty of Art and Design, UNAM, CDMX, Mexico. The proposal is conceived as a multidisciplinary exhibition project constituted by a set of heterogeneous subprojects, in synergy, joining forces, made with different disciplines and techniques such as collage, graphics and sculpture. The general approach of the work revolves around the problems faced by Mexican society: political corruption, large social inequalities, organized crime, discrimination suffered by indigenous peoples, the situation of women's helplessness in a pre-eminently macho environment and the intolerable indexes of feminicides. In short, a set of factors that destabilize the country and create insecurity in the population. Mexican Palimpsests also highlights the struggle for civil rights of the most disadvantaged sectors of society, and empowers and turns Mexican women into a symbol of hope for a better future. Proposing a drawing of Mexico away from the stereotypes and folklore that presumably defines their national identity. Providing a vision of the country different from the known imaginary, from a subjective point of view, of a political nature but not dogmatic. With the intention of showing, through contemporary art, a Mexico in construction with some problems to solve of stratospheric dimensions and fascinating in its future challenges. In a country, the most populous Spanish-speaking, which is called to be an economic power and a cultural reference on a global scale.Navarro Rodríguez, MÁ. (2019). Palimpsestos mexicanos. http://hdl.handle.net/10251/130234TFG

Los medios, el mensaje y la guerra. La instalación artística: aura y reauratización

Los mass media son un sistema complejo controlado por grupos de poder y élites económicas capaces de construir opinión pública desde la opinión publicada. Partiendo de esta premisa, en el presente artículo se propone un trabajo de investigación-creación, desde de una metodología cualitativa, a través de la indagación periodística y el análisis de textos en torno a la teoría del arte,  haciendo un recorrido por acontecimientos históricos del pasado siglo, en paralelo con el pensamiento de Walter Benjamin y el concepto de aura, para contraponerlos, en plena contemporaneidad, con la réplica de filósofos y críticos de arte como Boris Groys o José Luis Brea, que proponen una reauratización de las imágenes, todo ello ilustrado por un proyecto de instalación artística, hibridando disciplinas analógicas y digitales, cargando con ironía contra la manipulación de los medios de comunicación y proponiendo un espacio para la disidencia

DESAPARECIDAS. Investigación sobre la violencia de género y los feminicidios en México, desde la vídeo-instalación.

[ES] Desaparecidas, es una propuesta instalativa que denuncia las desapariciones de mujeres y los feminicidios en México, conjugando elementos escultóricos y audiovisuales, todo ello desde la poética del arte contemporáneo. Examinando referentes teóricos como Zygmunt Bauman o Irene Ballester, y artistas Mexicanas tales como: Lorena Wolffer, Mónica Mayer, Lourdes Grobet, y en el área de la videoinstalación, Ambra Polidori y Elina Chauvet. La propuesta DESAPARECIDAS, pretende crear un espacio de reflexión sobre la violencia de género en México, abordada desde el ámbito social y artístico. Así, a partir de una metodología cualitativa, de investigación de los contextos: geo-económico, político-social, estructurales y situacionales. El planteamiento general de la obra gira alrededor de la situación de indefensión que sufre la mujer mexicana frente a la violencia, en una sociedad eminentemente patriarcal. La hipótesis de esta investigación pretende demostrar la importancia del arte y de la videoinstalación como herramienta y estrategia discursiva para visibilizar y denunciar la problemática de la violencia en la sociedad. La instalación Desaparecidas, se compone de un conjunto de 45 máscaras escultóricas representando a la mujer anónima. La obra se completa con la proyección de dos videos que también muestran la imagen de una mujer asfixiada, en el contexto de la ciudad y el paisaje de México. En definitiva esta instalación pretende concienciar al espectador y ejercer una mirada crítica ante la problemática de la violencia de género y los arquetipos patriarcales enraizados en nuestra sociedad, una representación metafórica de la memoria de las víctimas.[EN] Missing, it is an installation proposal that denounces the disappearances of women and femicide in Mexico, combining sculptural and audiovisual elements, all from the poetics of contemporary art. Examining theoretical references such as Zygmunt Bauman or Irene Ballester, and artists Mexican women such as Lorena Wolffer, Mónica Mayer, Lourdes Grobet, and in the area of video installation, Ambra Polidori and Elina Chauvet. The Missing proposal aims to create a space for reflection on gender violence in Mexico, addressed from the social and artistic field. Thus, based on a qualitative methodology, for the investigation of contexts: geo-economic, political-social, structural and situational. The general approach of the work revolves around the situation of helplessness that Mexican women suffer in the face of violence, in an eminently patriarchal society. The hypothesis of this research aims to demonstrate the importance of art and video installation as a tool and discursive strategy to make visible and denounce the problem of violence in society. The Missing installation consists of a set of 45 sculptural masks representing the anonymous woman. The work is completed with the projection of two videos that also show the image of a suffocated woman, in the context of the city and the landscape of Mexico. In short, this installation aims to raise awareness among the viewer and exercise a critical look at the problem of gender violence and the patriarchal archetypes rooted in our society, a metaphorical representation of the victims' memory.Navarro Rodríguez, MÁ. (2020). DESAPARECIDAS. Investigación sobre la violencia de género y los feminicidios en México, desde la vídeo-instalación. Universitat Politècnica de València. http://hdl.handle.net/10251/158113TFG

The installation as a zone of blurring the limits in art

[EN] Practice-based research through the installation project Urban Dystopias; inequalities and social hierarchy in the contemporary city (Domene and Escoín, 2021). The concept of installation is analyzed as a point of confluence of artistic disciplines, overcoming the borders of academic tradition and where the ephemeral staging replaces the auratic object, giving way to art as experience. The capacity for mobility and adaptation of the installation is addressed, thanks to its space-time compositional versatility, “Since the artistic installation is a specific non-place, and can be installed anywhere for any period of time” (Groys, 2014, p.59). It also constitutes itself as a tool for critical interpretation of contemporaneity, in relation to: “the transgressions of the limits between art and life, art and politics, or art and theory”. (Rebentisch, 2018, p.17) The exhibition project of artistic production and research focuses on the symbolic representations of the contemporary city and the social inequalities derived from neoliberal economic models with the city as a hierarchical territory. The project portrays a dystopian reality that is in danger of collapsing the very foundations of capitalism due to the abusive accumulation of wealth and power by the elites (Piketty, 2014). The proposal materializes in a multidisciplinary artistic installation, from the concept of expanded field (Krauss, 1979), using hybrid resources such as traditional artistic techniques and audiovisual resources. In this way, an immersive experience is proposed through the three-dimensional exhibition space, converted into a metaphor of the urban territory, creating collages with images of various cities. This supports statistical data on income in the neighborhoods of these cities, as a strategy to make their economic differences visible.[ES] Investigación basada en la práctica mediante el proyecto de instalación Distopías urbanas; desigualdades y jerarquización social en la ciudad contemporánea (Domene y Escoín, 2021). Se analiza el concepto de instalación como punto de confluencia de las disciplinas artísticas, superando las fronteras de la tradición académica y donde la puesta en escena de carácter efímero sustituye a lo objetual aurático, dando paso al arte como experiencia. Se aborda la capacidad de movilidad y adaptación de la instalación, gracias a su versatilidad compositiva espacio-temporal. “Ya que la instalación artística es un no-lugar específico, y puede ser instalado en cualquier parte durante cualquier periodo de tiempo” (Groys, 2014). Constituyéndose, además, en herramienta de interpretación crítica de la contemporaneidad. Todo ello, en relación con las trasgresiones de los límites entre el arte y la vida, el arte y la política, o el arte y la teoría (Rebentisch, 2003). El proyecto expositivo de producción e investigación artística, se centra en las representaciones simbólicas de la urbe contemporánea y en las desigualdades sociales derivadas de los modelos económicos neoliberales con la ciudad como territorio jerarquizado. Una realidad distópica que corre el peligro de hacer colapsar las bases mismas del capitalismo, debido a la abusiva acumulación de riqueza y poder por parte de las élites (Piketty, 2013). La propuesta se materializa en una instalación artística multidisciplinar, desde el concepto de campo expandido (Krauss, 1979), utilizando recursos hibridados entre técnicas artísticas tradicionales y recursos audiovisuales. De esta forma, se propone una experiencia inmersiva a través del espacio expositivo tridimensional, convertido en metáfora del territorio urbano, creando collages con imágenes de diversas ciudades. Aportando datos estadísticos de las rentas en los barrios de dichas urbes, como estrategia de visibilización de sus divergencias económicas.Navarro Rodríguez, MÁ. (2022). La instalación como zona de difuminación de los límites en el arte. Editorial Universitat Politècnica de València. 367-374. https://doi.org/10.4995/ANIAV2022.2022.15471OCS36737

Predictive frequency-based sequence estimator for control of grid-tied converters under highly distorted conditions

This paper proposes a novel frequency-based predictive sequence extractor that allows to isolate the harmonic components of both voltages and currents needed for the control of grid-tied converters. The proposed method is based on a modification of the Sliding Goertzel Transformation (SGT) that allows to include a predictive behavior with a prediction horizon equal to the processing window needed for the algorithm. The technique performance is compared with the well-established DSOGI alternative, allowing for a higher bandwidth in the estimation as well as improved immunity to changes in the magnitude, frequency and phase of the tracked signals. Additionally, the impact of the proposed method on the closed-loop performance of the current controlled converter is proposed as a metric, thus enabling other researches to have a clear view about the expected real impact of the different existing methods

Limits, stability and disturbance rejection analysis of voltage control loop strategies for grid forming converters in DC and AC microgrids with high penetration of constant power loads

This paper extensively analyzes the operation limits, system stability and disturbance rejection capability of the voltage control loops used in master-slave AC and DC Microgrids (MGs). Two different control schemes are studied analytically, simulated and experimentally tested, focusing on Constant Power Loads (CPL). Additionally, the use of the virtual capacitance (VC) as a tool for response enhancement is introduced. The study pursues the proper selection of the controllers gains and minimization of capacitance values by considering the dynamic behavior

A Study on the Control Loop Design of Non-Isolated Configurations for Hybrid Storage Systems

This work focuses on the control strategies for different configurations of Non-Isolated Hybrid Energy Storage Systems. Basic strategies are proposed, studied and compared. Parting from the standard parallel connection of bidirectional boost converter in hybrid storage systems, a comparison with alternate topologies is presented. These alternative schemes overcome the problems that arise in the original configuration due the high mismatch in voltage ratings of the individual storage systems. A strategy to design the control loops of the resulting Hybrid Energy Storage System is proposed, studied, simulated and experimentally implemented on a 1.5 kW demonstrator. The control strategy is implemented in the standard bidirectional boost converter approach and also in the series-parallel connection of the storage units. The reported results show how the proposed control strategy applied to the series parallel connection presents a good performance in terms of dynamic and steady state operation.Plan de Ciencia Tecnología e Innovación del Principado de Asturias (PCTI), Fundación para el Fomento en Asturias de la Investigación Científica Aplicada y la Tecnología (FICYT), Programa Severo Ochoa de Ayudas Predoctorales para la formación en investigación y docencia del Principado de Asturias, ID BP13-138. Research, Technological Development and Innovation Program Oriented to the Society Challenges of the Spanish Ministry of Economy and Competitiveness under grant ENE2013-44245-R and by the European Union through ERFD Structural Funds (FEDER)

Non-Isolated High-Gain Three-Port Converter for Hybrid Storage Systems

This work proposes a non-isolated power electronic topology to interface two distinct electrical energy storage units to a DC link, resulting in a Hybrid Storage System. The proposed solution, called Series-Parallel Connection, allows for interfacing these three ports in a simple, compact and reliable approach, based on the standard configuration of the H-bridge converter. The main advantage is that one of the storage units can be of much smaller voltage ratings than the other two, avoiding the use of multilevel or galvanic-isolated power stages. The resulting structure is compared against the most significant transformerless alternatives based on the H bridge converter, stating their advantages and drawbacks. An analysis of the switching and conduction losses in the power switches of the proposed solution is carried out in order to state the design constraints at which this solution presents improved efficiency versus the alternatives. A final set of experiments in a 10 kW built prototype demonstrates the feasibility and states the benefits as well as the main limitations of the proposed scheme.Plan de Ciencia Tecnología e Innovación del Principado de Asturias (PCTI), Fundación para el Fomento en Asturias de la Investigación Científica Aplicada y la Tecnología (FICYT), Programa Severo Ochoa de Ayudas Predoctorales para la formación en investigación y docencia del Principado de Asturias, ID BP13-138. Research, Technological Development and Innovation Program Oriented to the Society Challenges of the Spanish Ministry of Economy and Competitiveness under grant ENE2013-44245-R and by the European Union through ERFD Structural Funds (FEDER)