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Optimització de la longitud de la cadena del reticulador i del fluoròfor en un material cristall líquid mecanofluorescent
No full textTreballs Finals de Grau de Química, Facultat de Química, Universitat de Barcelona, Any: 2026, Tutora: Maria Dolores Velasco CastrilloCurrently, there are various anisotropic materials with singular behaviors, whose mechanical, electrical or optical properties vary when an external stimulus is applied in a different orientation. Within this group of materials, we find those called Smart Materials (SM). These, when an external stimulus is applied to them, are capable of triggering a response, that is, they give rise to reversible changes in their properties, often associated with memory effects. Due to their peculiarity and their potential applications, these materials are studied in depth.
Our research has been based on the study of monodomain Liquid Single Crystal Elastomers (LSCEs) and on the analysis of the variation of their fluorescent response when an external mechanical force is applied to them. Furthermore, the effect of two different synthesis methods on the final optical properties possessed by the synthesized elastomers in each method has been compared. The static pool method proposed by our research group and the method reported by Küpfer and Finkelmann, which is based on polymerization in a rotating PTFE mould.
The elastomers that have been synthesized are composed of different monomers, among them, a fluorophore based on a carbazole functionalized with an aliphatic chain with a terminal double bond which is responsible for the fluorescence emission and a cross-linking agent derived from a hydroquinone substituted in the para position with two identical aliphatic chains that links the polymer chains. In this research, elastomers have been generated by combining fluorophores and cross-linkers with different aliphatic chain lengths in order to study their influence on the emitted mechanoluminescence.
The obtained results show that elastomers synthesized using the pool method do not exhibit fluorescence due to the quenching phenomenon of the fluorophore caused by its proximity to the mesogen. In contrast, elastomers synthesized using the centrifugation method trigger a mechanoluminescent response, since during the synthesis process, the centrifugal force induces an orientation of the monomers that prevents quenching. In addition, the use of cross-linkers with longer aliphatic chains, generates elastomers more readily.
Finally, the synthesized elastomers have been characterized using three techniques, a mechanoluminescence measurement and the swelling-deswelling process, which is used to determine the cross-linking state based from the degree of anisotropic swelling in different solvents and differential scanning calorimetry analysis
Self-consistency for multi-valued solutions and reasonable outcomes
No full textWe explore the compatibility of uniform self-consistency and ordinary self-consistency, two extensions for handling multi-valued solutions within the consistency principle introduced by Hart and Mas-Colell (1989), with basic properties, such as reasonableness, which establishes bounds for payoffs based on the marginality principle. Our analysis focuses on convex games and balanced games through the study of almost positive games, a subset of convex games that plays a crucial role in the vector lattice structure of games. Further, we provide new axiomatic foundations of the core incorporating these consistency properties
Financial crises and the global supply network: Evidence from multinational enterprise
No full textThis paper empirically examines the effects of financial crises on the organization of production of multinational enterprises. We construct a panel of European multinational networks from 2003 through 2015. We compute a multinational-specific shock based on the geographical structure of the network and the extent of the financial crisis in the countries belonging to the network. We document that multinationals facing a larger shock to their network experience lower growth in their number of affiliates and a deterioration in parents’ performance. This adjustment to the financial crisis is accounted for by multinationals with initially more leveraged parents, and it is exacerbated in networks more dependent on external financing. Moreover, initially more leveraged affiliates are more likely to be dropped from a multinational network. These findings lend support to financial frictions shaping multinational activity
Análisis del comportamiento de las plataformas de captación, selección y contratación de trabajadores que emplean algoritmos para la adopción de decisiones: evidencias
Get PDFEl empleo de los algoritmos por la empresa puede llevarse a cabo durante toda la vida de la relación laboral, ya que no solo se utilizan los mecanismo de inteligencia artificial antes de la contratación, en la selección de personal, sino también en la evaluación de capacidades y rendimientos entre otros
Supply Chain Sustainability Performance in the Manufacturing Sector of a Developing Economy
No full textTo assess supply chain (SC) sustainability performance, it is essential to understand the influence of key enablers. This study examines the impact of legal pressure, competitive pressure, internal resources and customer preferences on SC sustainability performance, with a particular focus on the mediating role of strategic direction. A quantitative survey was conducted with 390 operations managers from manufacturing sectors across Qatar, Saudi Arabia, the United Arab Emirates, Oman and Jordan. The data were analysed using partial least squares structural equation modelling (PLS-SEM). The results indicate that competitive pressure, internal resources and customer preferences significantly influence strategic direction, which in turn positively mediates their effect on sustainable supply chain (SSCM) performance. Legal pressure, however, was not found to significantly impact strategic direction, suggesting that regulatory mandates exert limited influence on manufacturing firms in the region. This study provides actionable insights for managers in developing strategic initiatives that enhance sustainability performance, particularly in contexts with constrained resources
Transient platelet hyporesponsiveness in non-ischemic arrhythmogenic cardiac arrest after achieving restoration of spontaneous circulation in pigs.
No full textThis study shows that variable and often attenuated platelet reactivity after CA, together with neutral OHCA outcome data argues against indiscriminate antiplatelet loading before the cause of shock is clarified. For ambiguous prehospital cardiogenic shock, initial management should prioritize early coronary angiography and comprehensive shock care, reserving full antiplatelet loading for those in whom AMI is confirmed or strongly suspected per local protocols
EU Digital Law. Art 7 DSA Voluntary own-initiative investigations and legal compliance
No full textProviders of intermediary services shall not be deemed ineligible for the exemptions from liability referred to in Articles 4, 5 and 6 solely because they, in good faith and in a diligent manner, carry out voluntary own initiative investigations into, or take other measures aimed at detecting, identifying and removing or disabling access to, illegal content, or take the necessary measures to comply with the requirements of Union Law and national law in compliance with Union Law, including the requirements set out in this regulation
Implementation and enforcement of environmental legislation as a cornerstone of the European Green Deal
No full textThis chapter will verify the extent of the lack of enforcement of EU environmental legislation, as well as of international legislation and State legislation in relation to the requirements set by the EGD. The main causes of this situation and its negative effects will be analysed. Some proposals are then made to better ensure the enforcement of environmental legislation and the role of the EU in its formulation and implementation, within the EU and its Member States and outside the EU. It will also pay attention on how to make information on the environmental law’s compliance available and accessible to the public
Repertorios de acción colectiva feminista: cuerpos, cuidados y desobediencias en el Chile revuelto
No full text[spa] La presente tesis analiza las acciones colectivas de activistas feministas y transfeministas durante la revuelta social chilena de octubre de 2019, enlazando estas acciones con los aprendizajes del Mayo Feminista de 2018, la Huelga General Feminista de 2019 y otros reclamos contra la precarización de vida en el neoliberalismo chileno. A partir de una trama conceptual que integra teoría de los movimientos sociales, estudios de género, epistemologías feministas y teoría social latinoamericana, la investigación permite conocer los repertorios de acción colectiva desplegados por los activismos feministas, con especial atención a las nuevas formas de protesta y marcos de significado emergentes que las/les activistas formularon durante la revuelta social. Asimismo, se exploran los espacios de acción y escenarios de intervención utilizados por los colectivos feministas y la manera en que extienden sus reclamos en distintos contextos durante la movilización social. A través de una triangulación metodológica que incluye revisión sistemática de literatura, entrevistas semi-estructuradas, estudio de caso, etnografía digital y análisis documental, se analiza la agencia política de los activismos feministas. Los resultados permiten observar innovaciones en los repertorios de acción colectiva, entre ellos: la transformación de la protesta al incorporar el cuerpo, los cuidados y la interdependencia en los reclamos colectivos que proyectan nuevas formas de entender la organización social y el espacio político; la capacidad para activar repertorios en contextos remotos y activar la solidaridad transfronteriza y un despliegue activista digital que difumina la distinción online/offline y no se escinde del cuerpo vulnerable. La investigación contribuye académicamente a las ciencias sociales y a los estudios de género al analizar estas prácticas feministas como acciones corporeizadas que redefinen la protesta y abren nuevas formas de acción política desde el Sur Global, proponiendo innovaciones teóricas y metodológicas para construir un análisis complejo de las acciones feministas en el contexto de la revuelta social de octubre de 2019.[eng] This thesis analyzes the collective actions of feminist and transfeminist activists during the Chilean social uprising of October 2019, linking these actions with the lessons learned from the Feminist May of 2018, the Feminist General Strike of 2019, and other demands against the precarization of life under Chilean neoliberalism. Drawing from a conceptual framework that integrates social movement theory, gender studies, feminist epistemologies, and Latin American social theory, the research sheds light on the repertoires of collective action deployed by feminist activism, with particular attention to the new forms of protest and emerging meaning frameworks formulated by the activists during the social uprising. Additionally, the research explores the spaces of action and intervention scenarios utilized by feminist collectives and how they extend their demands across different contexts during the social mobilization. Through a methodological triangulation that includes a systematic literature review, semi-structured interviews, case studies, digital ethnography, and document analysis, the political agency of feminist activism is examined. The findings reveal innovations in the repertoires of collective action, including: the transformation of protest by incorporating the body, care, and interdependence into collective demands, projecting new ways of understanding social organization and the political space; the ability to activate repertoires in remote contexts and foster transborder solidarity; and a digital activist deployment that blurs the online/offline distinction while remaining connected to the vulnerable body. The research makes an academic contribution to social sciences and gender studies by analyzing these feminist practices as embodied actions that redefine protest and open new forms of political action from the Global South, proposing theoretical and methodological innovations to construct a complex analysis of feminist actions in the context of the October 2019 social uprising.[cat] La present tesi analitza les accions col·lectives d'activistes feministes i transfeministes durant la revolta social xilena de l'octubre de 2019, enllaçant aquestes accions amb els aprenentatges del Maig Feminista de 2018, la Vaga General Feminista de 2019 i altres reivindicacions contra la precarització de la vida en el neoliberalisme xilè. A partir d’una trama conceptual que integra teoria dels moviments socials, estudis de gènere, epistemologies feministes i teoria social llatinoamericana, la investigació permet conèixer els repertoris d’acció col·lectiva desplegats pels activismes feministes, amb especial atenció a les noves formes de protesta i marcs de significat emergents que les/els activistes van formular durant la revolta social. Així mateix, s'exploren els espais d'acció i els escenaris d'intervenció utilitzats pels col·lectius feministes i la manera en què estenen les seves reivindicacions en diferents contextos durant la mobilització social. A través d'una triangulació metodològica que inclou revisió sistemàtica de literatura, entrevistes semiestructurades, estudis de cas, etnografia digital i anàlisi documental, s'analitza l'agència política dels activismes feministes. Els resultats permeten observar innovacions en els repertoris d'acció col·lectiva, entre elles: la transformació de la protesta en incorporar el cos, les cures i la interdependència en les reivindicacions col·lectives que projecten noves formes d'entendre l'organització social i l'espai polític; la capacitat per activar repertoris en contextos remots i activar la solidaritat transfronterera, i un desplegament activista digital que difumina la distinció online/offline i no es deslliga del cos vulnerable. La investigació contribueix acadèmicament a les ciències socials i als estudis de gènere en analitzar aquestes pràctiques feministes com accions corporitzades que redefineixen la protesta i obren noves formes d'acció política des del Sud Global, proposant innovacions teòriques i metodològiques per construir una anàlisi complexa de les accions feministes en el context de la revolta social d'octubre de 2019
Iron-manganese crystalline phases developed in high lead glazes during firing
No full textLead glazes have been coloured and decorated with iron and manganese oxides since ancient times. Duringfiring, these pigments react and form new crystalline compounds such as haematite, andradite, melanotekite,kentrolite, braunite, jacobsite and magnetoplumbite which have been identified in lead-glazed ceramics from the11th to 17th centuries. To determine the sequence of formation of these pigments, an X-ray powder diffractionexperiment was conducted at the ALBA synchrotron up to 928◦ C with various mixtures. The influence of Al2O3,CaO, and MgO was also studied. The sequence of crystalline phase formation in different systems was estab-lished, and laboratory recreations of glazed ceramics at temperatures from 850◦ C to 1020◦ C were analysed usingoptical and electronic microscopy. Understanding the sequence of formation of iron and manganese crystals inlead glazes helps to elucidate ancient production techniques and the final appearance of the glazes