234 research outputs found

    Spectral gap induced by structural corrugation in armchair graphene nanoribbons

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    We study the effects of the structural corrugation or rippling on the electronic properties of undoped armchair graphene nanoribbons (AGNR). First, reanalyzing the single corrugated graphene layer we find that the two inequivalent Dirac points (DP), move away one from the other. Otherwise, the Fermi velocity decrease by increasing rippling. Regarding the AGNRs, whose metallic behavior depends on their width, we analyze in particular the case of the zero gap band-structure AGNRs. By solving the Dirac equation with the adequate boundary condition we show that due to the shifting of the DP a gap opens in the spectra. This gap scale with the square of the rate between the high and the wavelength of the deformation. We confirm this prediction by exact numerical solution of the finite width rippled AGNR. Moreover, we find that the quantum conductance, calculated by the non equilibrium Green's function technique vanish when the gap open. The main conclusion of our results is that a conductance gap should appear for all undoped corrugated AGNR independent of their width.Comment: 7 pages, 5 figure

    ‘Buscamos una voz que nos reciba’. Narrativa chilena reciente: lecturas cómplices

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    This research explores certain suggested ways of reading recent Chilean narratives, focusing particularly on a corpus of works by four authors: Alvaro Bisama, Alejandra Costamagna, María José Viera-Gallo and Alejandro Zambra. It is proposed that from reception it is possible to specify certain ways of reading that manifest themselves in the degree of complicity achieved between the reader and the works, where this is defined by the reader’s cooperation or participation in the act of reading. The reader is drawn into the work by following the signs given in it, shifting from a critical to emotional reading by updating the stories through a close link between writer, the work and the reader. Thus the works are always read in a complicit way, but from different viewpoints and on different levels. Taking these nuances into account we aim to revise three ways of complicit reading: a) through appropriation of the past, b) politically and c) dynamically.<br><br>Esta investigación centra su estudio en algunas propuestas de lectura para la narrativa chilena reciente, especialmente un corpus compuesto por un conjunto de obras de cuatro autores: Álvaro Bisama, Alejandra Costamagna, María José Viera-Gallo y Alejandro Zambra. Se propone que desde la recepción es posible precisar algunas formas de lectura que se concretan pensando en el grado de complicidad que logra el lector con estas obras, determinada por su relación de colaboración o participación en el acto de leer. El lector se acercará más o menos a la obra siguiendo las señas propuestas en ella, así las formas de leer irán desde lo crítico hasta lo afectivo, actualizando los relatos a partir de un estrecho vínculo entre escritor, obra y lector. De esta forma la lectura siempre será cómplice, pero desde diferentes aspectos y en distintos grados. Teniendo en cuenta estos matices revisaremos tres formas de lectura cómplice: a) de apropiación del pasado, b) política y c) dinámica

    Melting of Partially Fluorinated Graphene: From Detachment of Fluorine Atoms to Large Defects and Random Coils

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    The melting of fluorographene is very unusual and depends strongly on the degree of fluorination. For temperatures below 1000 K, fully fluorinated graphene (FFG) is thermo-mechanically more stable than graphene but at Tm_m\approx2800 K FFG transits to random coils which is almost twice lower than the melting temperature of graphene, i.e. 5300 K. For fluorinated graphene (PFG) up to 30 % ripples causes detachment of individual F-atoms around 2000 K while for 40-60 % fluorination, large defects are formed beyond 1500 K and beyond 60% of fluorination F-atoms remain bonded to graphene until melting. The results agree with recent experiments on the dependence of the reversibility of the fluorination process on the percentage of fluorination.Comment: 16 pages, 6 figure

    Melting of Partially Fluorinated Graphene: From Detachment of Fluorine Atoms to Large Defects and Random Coils

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    The melting of fluorographene is very unusual and depends strongly on the degree of fluorination. For temperatures below 1000 K, fully fluorinated graphene (FFG) is thermo-mechanically more stable than graphene but at T m ≈ 2800 K FFG transits to random coils which is almost twice lower than the melting temperature of graphene, i.e. 5300 K. For fluorinated graphene (PFG) up to 30% ripples causes detachment of individual F-atoms around 2000 K while for 40-60% fluorination, large defects are formed beyond 1500 K and beyond 60% of fluorination F-atoms remain bonded to graphene until melting. The results agree with recent experiments on the dependence of the reversibility of the fluorination process on the percentage of fluorination.Fil: Singh, Sandeep Kumar. Universiteit Antwerpen. Department of Physics; BélgicaFil: Costamagna, Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Física de Rosario (i); Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, Ingeniería y Agrimensura; ArgentinaFil: Neek Amal, M.. Universiteit Antwerpen. Department of Physics; BélgicaFil: Peeters, F. M.. Universiteit Antwerpen. Department of Physics; Bélgic

    The future of Cybersecurity in Italy: Strategic focus area

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    This volume has been created as a continuation of the previous one, with the aim of outlining a set of focus areas and actions that the Italian Nation research community considers essential. The book touches many aspects of cyber security, ranging from the definition of the infrastructure and controls needed to organize cyberdefence to the actions and technologies to be developed to be better protected, from the identification of the main technologies to be defended to the proposal of a set of horizontal actions for training, awareness raising, and risk management

    Epithelioid Angiosarcoma of the Small Intestine After Occupational Exposure to Radiation and Polyvinyl Chloride: A case Report and Review of Literature

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    Angiosarcomas represent 1–2% of soft tissue sarcomas and most frequently occur in the subcutis. They may affect internal organs, such as the heart, liver, and spleen, and only rarely do they emerge in the gastrointestinal tract. The association between angiosarcomas and certain toxic chemical substances or previous external-beam radiation therapy is well documented

    Rational SOFC material design: new advances and tools

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    Solid oxide fuel cells (SOFCs) offer great prospects for the most efficient and cost-effective utilization of a wide variety of fuels. However, their commercialization hinges on the rational design of low cost materials with exceptional functionalities. This article highlights some recent progress in probing and mapping surface species and incipient phases relevant to electrode reactions using in situ Raman spectroscopy, synchrotron based x-ray analysis, and multi-scale modeling of charge and mass transport. The combination of in situ characterization and multi-scale modeling is imperative to unraveling the mechanisms of chemical and energy transformation: a vital step for the rational design of next generation SOFC materials.open443

    SPARC 2017 retrospect & prospects : Salford postgraduate annual research conference book of abstracts

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    Welcome to the Book of Abstracts for the 2017 SPARC conference. This year we not only celebrate the work of our PGRs but also the 50th anniversary of Salford as a University, which makes this year’s conference extra special. Once again we have received a tremendous contribution from our postgraduate research community; with over 130 presenters, the conference truly showcases a vibrant PGR community at Salford. These abstracts provide a taster of the research strengths of their works, and provide delegates with a reference point for networking and initiating critical debate. With such wide-ranging topics being showcased, we encourage you to exploit this great opportunity to engage with researchers working in different subject areas to your own. To meet global challenges, high impact research inevitably requires interdisciplinary collaboration. This is recognised by all major research funders. Therefore engaging with the work of others and forging collaborations across subject areas is an essential skill for the next generation of researchers
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