An upper bound for the magnetic force gradient in graphite

Cervenka et al. have recently reported ferromagnetism along graphite steps. We present Magnetic Force microscopy (MFM) data showing that the signal along the steps is independent of an external magnetic field. Moreover, by combining Kelvin Probe Force Microscopy (KPFM) and MFM, we are able to separate the electrostatic and magnetic interactions along the steps obtaining an upper bound for the magnetic force gradient of about16 microN/m, a figure six times lower than the lowest theoretical bound reported by Cervenka et al. Our experiments suggest absence of MFM signal in graphite at room temperature.Comment: 14 pages, including supplemetary informatio

Detection of Tephra Layers in Antarctic Sediment Cores with Hyperspectral Imaging

Tephrochronology uses recognizable volcanic ash layers (from airborne pyroclastic deposits, or tephras) in geological strata to set unique time references for paleoenvironmental events across wide geographic areas. This involves the detection of tephra layers which sometimes are not evident to the naked eye, including the so-called cryptotephras. Tests that are expensive, time-consuming, and/or destructive are often required. Destructive testing for tephra layers of cores from difficult regions, such as Antarctica, which are useful sources of other kinds of information beyond tephras, is always undesirable. Here we propose hyperspectral imaging of cores, Self-Organizing Map (SOM) clustering of the preprocessed spectral signatures, and spatial analysis of the classified images as a convenient, fast, non-destructive method for tephra detection. We test the method in five sediment cores from three Antarctic lakes, and show its potential for detection of tephras and cryptotephras.info:eu-repo/semantics/publishedVersio

Mechanical Isolation of Highly Stable Antimonene under Ambient Conditions

Using mechanical exfoliation combined with a controlled double step transfer procedure we demonstrate that single layers of antimony can be readily produced. These flakes are not significantly contaminated upon exposure to ambient conditions and they do not react with water. DFT calculations confirm our experimental observations and predict a band gap of 1.2-1.3 eV (ambient conditions) for single layer antimonene, which is smaller than that calculated under vacuum conditions at 0 K. Our work confirms antimonene as a highly stable 2D material with promising relevant applications in optoelectronics.Comment: main paper: 5 pages, 4 figures supporting: 9 pages, 7 figures, Advanced Materials, 201

Arquitectura por horas

Los alumnos de proyectos 2 [grupos 9+11] de la E.T.S.A.S. realizan como ejercicio final de curso la acción urbana denominada “arquitectura por horas”, que se muestra en un contexto muy concurrido, La Puerta de Jerez y los espacios de la Casa de la Moneda de Sevilla. Los estudiantes, con esa acción colectiva, persiguen que los habitantes de la calle interactúen con una performance de objetos y descubrir en las reacciones los mecanismos que producen interacciones. La acción convierte la calle en un laboratorio social donde convergen acciones y respuestas. La actividad, que se ha desarrollado bajo el lema 'Reducir, reciclar, reutilizar'. Cinco acciones de ámbito académico pensadas para un contexto urbano que se recicla: usamos su materialidad y añadimos otros materiales procedentes de reciclajes: plástico, papel, metal, neumáticos, embalajes,… Cinco colores concurren sobre el tablero de juego: Negro, rojo, (blanco – verde), (amarillo – ocre), azul. Un contexto, la Casa de la Moneda y su entorno inmediato, previamente analizado y conocido. Las propuestas intentan conjugar planteamientos conceptuales con un proceso metódico de alegorías visuales, que son extremadamente sencillas y no están exentas de humor e ironía. Cinco Instalaciones efímeras que en cinco horas, se montan, interactúan y desaparecen. Se diseña un foro de intercambio de experiencias entre profesores, alumnos, viandantes,... La arquitectura como objeto y descubrimiento que desvela, superado el objeto en sí, como actúa sobre los sujetos y cual es su capacidad de provocar situaciones. El paseante toma partido ante lo insólito, inusual, inesperado,... y la experiencia se convierte en celebración de los pobladores de la calle. Sabemos que lo inusual, en ocasiones pasa inadvertido y en otras se presenta como revulsivo o subversivo. Durante cinco horas registramos imágenes del tránsito para documentar las respuestas a las provocaciones, el comportamiento del espectador ante el objeto. Acciones de réplica o indiferencias.The E.T.S.A.S. students from the course Proyectos2 [groups 9 and 11] performed as final exercise the urban action called “Architecture per hours”, within a concurred context: La Puerta de Jerez and the spaces from la Casa de la Moneda de Sevilla. The students pursue through this collective action that the people on the street interact through a performance with objects so the students can find out by their reactions the motions that the interactions generate. This performance turns the streets into a social laboratory where actions and responses are being converged. In addition, this activity has been worked out by the theme “Reduce, recycle, reuse”. The result is five educational actions thought for a specific context where recycling is important: we use its materiality and we add different materials of recycling, such as plastic, paper, metal, tires, cardboards… Five different colors are being played on the game board: black, red, whitegreen, yellow-ocher and blue. One concrete context: la Casa de la Moneda and its closest surroundings, which we previously analyzed and studied. The proposals try to mix up conceptual ideas with an intentional visual game, whose intentions are extremely simple and not far from humor and irony. In conclusion, five ephemeral interventions which are built, used and disappeared in only five hours. It is designed an exchange forum of collective experiences between professors, students, people on the street… Architecture is like an object which once is overcome, it can find out how to interact with the subjects and how far it can get to provoke a situation. The walking person takes part confronting the unusual, the extraordinary, the unexpected… So this experience is turned into a celebration by its public. We all know that the unusual is rarely noticed except when it shows revulsion or subversive. For more than five hours we recorded images and videos of the public flux so we could document the diverse responses and reactions caused by the objects, even the revulsion actions or the indifferent behaviors

Improving the Lateral Resolution of Quartz Tuning Fork-Based Sensors in Liquid by Integrating Commercial AFM Tips into the Fiber End

The use of quartz tuning fork sensors as probes for scanning probe microscopy is growing in popularity. Working in shear mode, some methods achieve a lateral resolution comparable with that obtained with standard cantilevered probes, but only in experiments conducted in air or vacuum. Here, we report a method to produce and use commercial AFM tips in electrically driven quartz tuning fork sensors operating in shear mode in a liquid environment. The process is based on attaching a standard AFM tip to the end of a fiber probe which has previously been sharpened. Only the end of the probe is immersed in the buffer solution during imaging. The lateral resolution achieved is about 6 times higher than that of the etched microfiber on its own

Ultralarge Free-Standing Imine-Based Covalent Organic Framework Membranes Fabricated via Compression

Demand continues for processing methods to shape covalent organic frameworks (COFs) into macroscopic objects that are needed for their practical applications. Herein, a simple compression method to prepare large-scale, free-standing homogeneous and porous imine-based COF-membranes with dimensions in the centimeter range and excellent mechanical properties is reported. This method entails the compression of imine-based COF-aerogels, which undergo a morphological change from an elastic to plastic material. The COF-membranes fabricated upon compression show good performances for the separation of gas mixtures of industrial interest, N2/CO2 and CH4/CO2. It is believed that the new procedure paves the way to a broader range of COF-membranes

Arquitectura por Horas: acciones e interacciones en el espacio colectivo

Presentamos para esta publicación un artículo publicado en inglés e italiano en el año 2012 como “Architetture “Part time”. Azioni e interazioni per lo Spazio Collettivo” (“Architecture “Part time”. Actions and interactions for the collective space”), En Reduce-Recycle- Reuse, Arti performative in spazi urbani. De Vittorio Fiore, Francesca Castagneto, Lettera Ventidue Edicioni . Artículo por tanto, inédito en castellano. La vigencia, tanto de los ejercicios, como de las reflexiones, nos animan a publicarlo en esta ocasión, en su versión en castellano, tal y como fue publicado en los otros idiomas. Los cursos de los que se da cuenta, es la primera experiencia que el conjunto de profesores que la publican, realizaron en Proyectos 1 y Proyectos 2, dos cursos centrados en el proceso de creación, el papel del cuerpo en el proyecto y la construcción de lo real. Las premisas y los ejercicios propuestos (todos centrados en el desarrollo de procesos creativos de corta duración, en la interacción con el espacio urbano, colectivo y social , además de la necesidad impuesta de la ejecución a 1:1 de las propuestas), nos siguen apareciendo vigentes y las acciones trasladables a nuevas experiencias, para aprender, como en el texto expone, no tanto “qué es la arquitectura”, sino lo que en ella acontece.We presented for this publication an article published in English and Italian in 2012 as “Architetture “Part time”. Azioni e interazioni per lo Spazio Collettivo” (“Architecture “Part time”. Actions and interactions for the collective space”), En Reduce-Recycle- Reuse, Arti performative in spazi urbani. By Vittorio Fiore, Francesca Castagneto, Lettera Ventidue Edicioni . Article therefore, unpublished in Spanish. The validity, both of the exercises and of the reflections, encourage us to publish it on this occasion, in its version in Spanish, as it was published in the other languages. The courses of which he realizes, is the first experience that the set of teachers who publish it, carried out in Projects 1 and Projects 2, two courses focused on the creation process, the role of the body in the project and the construction of the real. The premises and the proposed exercises (all focused on the development of short-term creative processes, on interaction with urban, collective and social space, in addition to the imposed need for the implementation at 1:1 of the proposals), follow us appearing and actions transferable to new experiences, to learn, as in the text exposes, not so much “what is architecture”, but what is happening in it

Nematicidal effect of Beauveria species and the mycotoxin beauvericin against pinewood nematode Bursaphelenchus xylophilus

The International Union of Forest Research Organisations (IUFRO) Conference: Foliar, Shoot, Stem and Rust Diseases of Trees Jointly organized by IUFRO working parties “Foliage, shoot, and stem diseases" (7.02.02) and "Rusts of Forest Trees" (7.02.05) is taking place in June of 2022 in Durham, New Hampshire, USA. This international conference, which meets every two to four years, provides a great opportunity for discussion among colleagues working with rust, foliage and stem diseases of forest trees in different regions of the world. Plant pathogens do not recognize boundaries, therefore maintaining a global perspective when it comes to forest health protection is essential. Topics of interest that will be covered at the conference include: - invasive forest pathogens; - disease management and control; - plant defence; - climate change; - rust, foliage, shoot, and stem diseases. The goal of this Research Topic is to feature recent advances in research concerning forest diseases, climate change and their management, welcoming abstracts presented at the IUFRO Foliar, Shoot, Stem and Rust Diseases of Trees 2022

Few-layer antimonene electrical properties

Antimonene -a single layer of antimony atoms- and its few layer forms are among the latest additions to the 2D mono-elemental materials family. Numerous predictions and experimental evidence of its remarkable properties including (opto)electronic, energetic or biomedical, among others, together with its robustness under ambient conditions, have attracted the attention of the scientific community. However, experimental evidence of its electrical properties is still lacking. Here, we characterized the electronic properties of mechanically exfoliated flakes of few-layer (FL) antimonene of different thicknesses (∼ 2–40 nm) through photoemission electron microscopy, kelvin probe force microscopy and transport measurements, which allows us to estimate a sheet resistance of ∼ 1200 Ω sq−1 and a mobility of ∼ 150 cm2V−1s−1 in ambient conditions, independent of the flake thickness. Alternatively, our theoretical calculations indicate that topologically protected surface states (TPSS) should play a key role in the electronic properties of FL antimonene, which supports our experimental findings. We anticipate our work will trigger further experimental studies on TPSS in FL antimonene thanks to its simple structure and significant stability in ambient environmentsWe acknowledge financial support through the “Maríade Maeztu” Programme for Units of Excellence in R&D (CEX2018-000805-M), the Spanish MINECO through projects PCI2018-093081, FIS2016-80434-P, PID2019-109539GB-C43, PID2019- 106268GB-C31 and -C32, MAT2016-77608-C3-1-P and -3-P, MAT2013-46753-C2-2-P and MAT2017-85089-C2-1R, the EU Graphene Flagship funding (Graphene Flagship Core3 881603 and JTC2017/2D-Sb&Ge), the EU via the ERC-Synergy Program (GrantERC-2013-SYG-610256 NANOCOSMOS), the Comunidad Autónoma de Madrid through MAD2D-CM, S2018/NMT-4321 (NanomagCOST-CM) and the European StructuralFunds via FotoArt CM project (S2018/NMT-4367), and the Fundación Ramón Areces. S.P. acknowledges financial support by the VILLUM FONDEN via the Centre of Excellence for Dirac Materials (Grant No. 11744