85 research outputs found

    Janus organic semiconductor nanoparticles prepared by simple nanoprecipitation

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    Nanoparticles (NPs) of donor–acceptor organic semiconductors are produced by a one-step nanoprecipitation with Janus morphology. Electron donor P3HT was blended with electron acceptor PC61BM in tetrahydrofuran and then precipitated in water, first with surfactant and second without surfactant. Cryogenic transmission electron microscopy reveals an internal Janus structure at high magnification, for NPs which have, in the past, been reported to have a molecularly intermixed morphology. Synchrotron-based scanning transmission X-ray microscopy confirmed the segregation of the organic semiconductors and photoluminescence experiments showed an efficient electron transfer from P3HT to PC61BM. Organic field effect transistors were fabricated with these Janus NPs and showed that the positive charges can be efficiently transported through thin films. This behavior proves that the NPs possess an electron-accepting face (the PC61BM face) able to transport electrons and a hole-accepting face (the P3HT face) for the conduction of holes. Finally, the deposition of silver via the photoreduction of a silver salt (AgNO3(aq)) was demonstrated, as a proof of concept. These experiments show the potential of the Janus NPs for photovoltaics but also photocatalytic reactions in which reduction and oxidation reactions can occur at opposite sides of the nanoreactor (the individual Janus NPs).E2SEncres aqueuses colloïdales de semi-conducteurs organiques pour le photovoltaïqu

    Solidarity in the wake of COVID-19: reimagining the International Health Regulations

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    Amid frenzied national responses to COVID-19, the world could soon reach a critical juncture to revisit and strengthen the International Health Regulations (IHR), the multilateral instrument that governs how 196 states and WHO collectively address the global spread of disease.1, 2 In many countries, IHR obligations that are vital to an effective pandemic response remain unfulfilled, and the instrument has been largely side-lined in the COVID-19 pandemic, the largest global health crisis in a century. It is time to reimagine the IHR as an instrument that will compel global solidarity and national action against the threat of emerging and re-emerging pathogens. We call on state parties to reform the IHR to improve supervision, international assistance, dispute resolution, and overall textual clarity

    Four challenges in the field of alternative, radical and citizens’ media research

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    In January 1994 the Zapatista movement in southern Mexico inaugurated a new era of media use for dissent. Since that time, an array of dissenting collectives and individuals have appropriated media technologies in order to make their voices heard or to articulate alternative identities. From Zapatista media to the Arab Spring, social movements throughout the world are taking over, hybridizing, recycling, and adapting media technologies. This new era poses a new set of challenges for academics and researchers in the field of Communication for Social Change (CfSC). Based on examples from Mexico, Lebanon, and Colombia, this article highlights and discusses four such research challenges: accounting for historical context; acknowledging the complexity of communication processes; anchoring analysis in a political economy of information and communication technologies; and positioning new research in relation to existing knowledge and literature within the field of communication and social change.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    Communication for Peaceful Social Change and Global Citizenry

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    The adoption of the 17 Sustainable Development Goals (SDGs) by the United Nations (UN) in 2015 represents a universal call to action involving multiple international actors for the purpose of eradicating poverty, improving living conditions and promoting peace. This entry provides a theoretical overview of the contributions of scholars and practitioners who highlight the importance of a transformative, educational and emancipatory communication by different social actors to establish the main lines of action for the 2030 Agenda for Sustainable Development. This communicative model involves the coordination of actors and strategies, both short- and long-term, cross-cutting actions and discourses to build social, cultural and political settings based on the criteria of peace, equality, social justice and human rights. Specifically, this entails a contribution to the objectives set out in SDG 16, “Peace, Justice and Strong Institutions”, given that the proposed theoretical framework is grounded in Communication for Peace and Communication for Social Change, and includes a systematization of different strategies and experiences from a variety of social issuers, mainly institutions, non-governmental organizations (NGOs) or social movements, aimed at promoting peaceful and inclusive societies. Specifically, communication for peaceful social change and global citizenry contributes to the achievement of specific SDG 16 objectives, particularly 16.1: Significantly reduce all forms of violence... [...

    Comunicación educación un campo de resistencias

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    El presente libro obedece a la imperiosa necesidad de desplegar la potencia de la Facultad de Ciencias de la Comunicación en la Corporación Universitaria Minuto de Dios -UNIMINUTO, de otras comunidades académicas y de los espacios de movimiento social interesados en deconstruir los discursos de comunicación y educación desde la perspectiva del pensamiento crítico. En este caso entendemos potencia como la fuerza individual y colectiva capaz de rebasar la racionalidad dominante en la sociedad contemporánea, colonizada por la economía como única mirada del mundo; esto es, potencia como ímpetu insospechado por el poder. Por otra parte, el libro tiene como eje articulador el concepto de resistencia, definido este como el acto de recrear la realidad a partir de las posibilidades que ofrece la comunicación, para generar producción de sentido y dinamizar el cambio social. Propone realizar el ejercicio de concebir el mundo desde una perspectiva diferente a la hegemónica y de crear multiplicidades que trabajen unidas, reconociendo sus diferencias pero vinculándose en un “lugar común” del cual, cada una de ellas, regrese a su lugar cotidiano transformada por la acción colectiva del campo de Comunicación - Educación
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