Adhesion mechanics of graphene membranes

The interaction of graphene with neighboring materials and structures plays an important role in its behavior, both scientifically and technologically. The interactions are complicated due to the interplay between surface forces and possibly nonlinear elastic behavior. Here we review recent experimental and theoretical advances in the understanding of graphene adhesion. We organize our discussion into experimental and theoretical efforts directed toward: graphene conformation to a substrate, determination of adhesion energy, and applications where graphene adhesion plays an important role. We conclude with a brief prospectus outlining open issues.Comment: Review article to appear in special issue on graphene in Solid State Communication

Harmonization of hyperspectral and multispectral data sets

Many applications of earth observation missions rely on time series data. Combination of data from different missions makes the time series denser and thus has the potential to provide more information. However, data from different missions have to be harmonized to be analysed together in one time series. The Sen2Like project started to harmonize Sentinel-2 and Landsat-8 data and included an investigation how to add data from hyperspectral missions. The harmonization process includes a consistent cloud screening and atmospheric correction, spectral adjustment, BRDF adjustments and re-gridding. The presentation will give some recommendations on harmonisation of data formats and products to make easier the data fusion process. Multispectral earth observation data from several missions are already available since decades thus providing an incredible time series for many applications. These time series cannot be replaced by hyperspectral data, but supplemented. Implementation of hyperspectral data into multispectral Sen2Like framework is possible in two different ways regarding cloud screening and atmospheric correction. Either the atmospheric correction is performed on hyperspectral L1C-data or on multispectral L1C data generated from the hyperspectral origin. Results show only small differences between both ways

Cooperación, comunicación y sociedad: escenarios europeos y latinoamericanos

Como resultado de los debates y reflexiones generados en el marco de la XV edición de la Cátedra Europa surge este libro, en el que se recopilan algunos de los temas tratados en el marco de este evento por destacados investigadores de diferentes instituciones de Colombia y Europa, quienes nos permiten acercarnos transversalmente a interesantes temas que hoy siguen estando en las primeras líneas de debate actual en nuestras instituciones y sociedades. El espíritu que representa este libro, la integración y el trabajo colaborativo para acercarnos a diferentes perspectivas, lo cual cobra mucha importancia en un mundo cada vez más convulso, como resultado del recrudecimiento de la crisis que hoy afecta a los países considerados hasta ahora desarrollados, mientras que los ubicados en el marco de las “vías en desarrollo” comienzan a dejar de serlo para convertirse en referentes en medio de este difícil escenario global. Si hacemos uso de lo señalado por el rey de España en el marco de la pasada Cumbre de Estados Iberoamericanos, realizada en Cádiz en 2012, al momento de destacar la necesidad de que España estreche lazos con Iberoamérica para superar la crisis, creemos que el mundo de hoy necesita de espacios que ayuden a crear puentes sólidos y estrechos entre ambas orillas. Es por esto que los 7 capítulos que integran este libro buscan contribuir a este acercamiento. El “puente” que seguimos construyendo a través de este libro mira al pasado, presente y futuro de varios temas de especial relevancia. En los 7 tramos (capítulos) podremos tener acceso a reflexiones en torno a la cooperación Sur-Sur que comienza a cobrar fuerza en Colombia y el resto de América Latina, el proceso de adaptación que viven los migrantes colombianos en España, un abordaje reflexivo de la realidad social desde el punto de vista de uno de los principales teóricos sociales alemanes (Luhmann); pero además aborda el rol que están teniendo las redes sociales y el conectivismo desde las escuelas y las organizaciones no gubernamentales y el uso del lenguaje nazi y la enseñanza del alemán como lengua extranjera. Cada uno de los aportes de los diferentes autores de este libro esperamos que ayuden a un acercamiento transversal de una diversidad de temas, y a seguir abonando el terreno que, hoy más que nunca, necesita ser trabajado para que se logre superar la actual crisis social que vive el mundo, desde un marco en el que la perspectiva Norte-Sur se rompa a favor de un diálogo más igualitario entre todas las partes

Un Capítulo de la historia de Carlos V

Incluye grabados de Carlos V y Zumalacárregui, éste último de A. Maurin y una carta facsímil de ZumalacárreguiDigitalización. Vitoria-Gasteiz : Archivos y Bibliotecas, Abril 199

New Species in the Old World: Europe as a Frontier in Biodiversity Exploration, a Test Bed for 21st Century Taxonomy

The number of described species on the planet is about 1.9 million, with ca. 17,000 new species described annually, mostly from the tropics. However, taxonomy is usually described as a science in crisis, lacking manpower and funding, a politically acknowledged problem known as the Taxonomic Impediment. Using data from the Fauna Europaea database and the Zoological Record, we show that contrary to general belief, developed and heavily-studied parts of the world are important reservoirs of unknown species. In Europe, new species of multicellular terrestrial and freshwater animals are being discovered and named at an unprecedented rate: since the 1950s, more than 770 new species are on average described each year from Europe, which add to the 125,000 terrestrial and freshwater multicellular species already known in this region. There is no sign of having reached a plateau that would allow for the assessment of the magnitude of European biodiversity. More remarkably, over 60% of these new species are described by non-professional taxonomists. Amateurs are recognized as an essential part of the workforce in ecology and astronomy, but the magnitude of non-professional taxonomist contributions to alpha-taxonomy has not been fully realized until now. Our results stress the importance of developing a system that better supports and guides this formidable workforce, as we seek to overcome the Taxonomic Impediment and speed up the process of describing the planetary biodiversity before it is too late

Evaluation of SEN2COR surface reflectance products over land surface with reference measurements on ground

Sen2Cor is the atmospheric correction processor selected by ESA for operational, systematic processing of Copernicus Sentinel-2 mission data. It is used for generating the Level 2A products distributed to users by the Copernicus SciHub. Accurate atmospheric correction of Sentinel-2 data and knowledge of its uncertainties are preconditions for high quality downstream applications. In this work we present the comparison of Sentinel-2 Bottom-of-Atmosphere products with measurements of surface reflectance on ground. Source of reference measurements are both surface reflectance data from RadCalNet and from dedicated field campaigns. The analysis shows, that the uncertainty of SR-retrieval with Sen2Cor is better than about 7% for bright surfaces and about 17% for darker. In addition to this performance evaluation, the data are also applied to compare the use of reference data coming from permanent operating bright RadCalNet sites and from ad-hoc field campaigns at darker sites

Microwave to millimeter-wave electrodynamic response and applications of semiconductor nanostructures: LDRD project 67025 final report.

Solid-state lighting (SSL) technologies, based on semiconductor light emitting devices, have the potential to reduce worldwide electricity consumption by more than 10%, which could significantly reduce U.S. dependence on imported energy and improve energy security. The III-nitride (AlGaInN) materials system forms the foundation for white SSL and could cover a wide spectral range from the deep UV to the infrared. For this LDRD program, we have investigated the synthesis of single-crystalline III-nitride nanowires and heterostructure nanowires, which may possess unique optoelectronic properties. These novel structures could ultimately lead to the development of novel and highly efficient SSL nanodevice applications. GaN and III-nitride core-shell heterostructure nanowires were successfully synthesized by metal organic chemical vapor deposition (MOCVD) on two-inch wafer substrates. The effect of process conditions on nanowire growth was investigated, and characterization of the structural, optical, and electrical properties of the nanowires was also performed