Enhanced stability of hydrogen atoms at the graphene/graphane interface of nanoribbons

The thermal stability of graphene/graphane nanoribbons (GGNRs) is investigated using density functional theory. It is found that the energy barriers for the diffusion of hydrogen atoms on the zigzag and armchair interfaces of GGNRs are 2.86 and 3.17 eV, respectively, while the diffusion barrier of an isolated H atom on pristine graphene was only ~0.3 eV. These results unambiguously demonstrate that the thermal stability of GGNRs can be enhanced significantly by increasing the hydrogen diffusion barriers through graphene/graphane interface engineering. This may provide new insights for viable applications of GGNRs.Comment: 13 pages, 1 figure, 2 tables to appear in Appl. Phys. Let

Constraints on Mirror Fermion Mixing Angles from Anomalous Magnetic Moment Data

The new contributions to the electron (muon) anomalous magnetic moment arising in mirror fermion theories have been calculated. Imposing the experimental constraint lowers the current upper bound on the ordinary - mirror lepton mixing angles by a factor of 50 making predictions for mirror lepton production at HERA undetectably small. A way out is to allow for different mixing angles of the L and R field components. Choosing very small right mixing angles compatibility with the anomalous magnetic moment measurement may be easily maintained, while choosing left mixing angles close to the upper limits yields still reasonable HERA cross-sections.Comment: 10 pages, 2 figures (not included), Latex file; ITP-BUDAPEST REPORT NO. 48

Effect of the presence of lysated lees on polysaccharides, color and main phenolic compounds of red wine during barrel ageing

A practice in wineries is to age wine in the presence of lysated lees instead of fresh lees, in order to reduce the time wine is conserved on lees and avoid possible microbiological and organoleptic risks caused by lees. Two treatments were used to induce lees lysis: acidification and acidification in combination with a mixture of -glucanases and pectinases. Acidification treatment in combination with enzymes induced significantly greater mannoprotein and glucan release. The presence of lysated lees during wine storage in barrels produced wines with significantly different tannin contents. The ageing technique on lysated lees by acidification in combination with enzymes produced wines with more intense colors, lower luminosity and saturation, and a slight tendency towards red tones, and an increase in sweetness, fullness and mouth length. On the contrary, ageing technique on lysated lees by acidification increased wine acid and fresh sensations. © 2010 Elsevier Ltd

SemTab 2019: Resources to Benchmark Tabular Data to Knowledge Graph Matching Systems

Tabular data to Knowledge Graph matching is the process of assigning semantic tags from knowledge graphs (e.g., Wikidata or DBpedia) to the elements of a table. This task is a challenging problem for various reasons, including the lack of metadata (e.g., table and column names), the noisiness, heterogeneity, incompleteness and ambiguity in the data. The results of this task provide significant insights about potentially highly valuable tabular data, as recent works have shown, enabling a new family of data analytics and data science applications. Despite significant amount of work on various flavors of this problem, there is a lack of a common framework to conduct a systematic evaluation of state-of-the-art systems. The creation of the Semantic Web Challenge on Tabular Data to Knowledge Graph Matching (SemTab) aims at filling this gap. In this paper, we report about the datasets, infrastructure and lessons learned from the first edition of the SemTab challenge

Sentinel 2 as a visualization tool of the historical urban growth of cities

La observación multiespectral de las ciudades desde el espacio es una herramienta sumamente valiosa para conocer la situación actual de las mismas. Sin embargo, estas mismas imágenes pueden aportar información también sobre la historia pasada de las mismas. En este trabajo se propone el procesado de imágenes Sentinel 2 para visualizar el crecimiento urbano de las ciudades a lo largo del tiempo. En concreto, se ha usado la combinación de bandas 12,11,4 y 12,8,3 para obtener imágenes en falso color que resaltan intensamente los diferentes materiales de techado utilizados en el tiempo. Esta combinación de bandas infrarrojas y roja resultan muy útiles para diferenciar materiales como la teja, el cemento o los materiales sintéticos impermeabilizantes, permitiendo diferenciar a simple vista los distintos barrios que forman la ciudad en función de su época de construcción, dando una visión global de las fases de crecimiento de la ciudad. Este tipo de imágenes resultan muy intuitivas para los estudiantes, convirtiéndose en una valiosa herramienta didáctica y de divulgaciónMultispectral observation of cities from space is a key tool for understanding their current state. Moreover, this kind of imagery may provide insight into the past history of cities. This work proposes the process of Sentinel 2 images for visualizing urban growth of cities in time. In particular, RGB composite of bands 12,11,4 and 12,8,3 provide false color images that highlight the different roofing materials used through history. This particular combination of infrared and red bands are very useful for differentiating materials such as red tile, cement or sinthetic impermeabilization materials, allowing to visually different phases of city growth. These images are very intuitive for students and non professionals, becoming a valuable tool for history teaching and divulgatio

Seasonal Growth Curves of Perennial Ryegrass in Mexico

An experiment was established at Colegio de Postgraduados Research Station, Texcoco, México to evaluate the seasonal pattern of growth curve of perennial ryegrass (Lolium perenne) swards. Growth rate increases rapidly from a low level immediately after defoliation, and eventually reaches an equilibrium level as the amount of green leaf in the sward stabilize. The time required to reach this state varied according to the season of year, with the four seasons ranked in the order: spring (4 weeks) \u3c summer (5 weeks) \u3c autumn and winter (6 weeks). Once swards reached equilibrium, growth rates started to decline as a consequence of an increase in dead material and pseudostem. These increases were highest in spring and lowest in winter. The results of this study suggest that sward management to maximise herbage production and utilisation in ryegrass swards must be done once the highest green leaf mass is reached. In this trial, it was reached at 5, 6, 6 and 4 weeks in summer, autumn, winter and spring, respectively

Studying mathematics students’ learning experiences in Challenge-based education

This paper is of methodological nature. We present the empirical research methodology of a study that focuses on student learning experiences, in particular of mathematics students in an innovative learning environment, such as Challenge-based Education (CBE) at a Dutch university of technology. In this study, we present the case study of CBE in an innovative mathematics course on modelling, the mathematics “Modelling Week”. We draw attention to the methodology used to study this modelling course, where we investigated students' learning experiences in a monodisciplinary CBE-oriented master course. We explain the design of the study and the associated data collection strategies regarding students' use of resources (Schematic Representation of Resource system- SRRS) and their learning processes. In the poster presentation, we will show selected results that come from the different instruments to help us understand student learning experiences in innovative/CBE related mathematics courses.</p