XPS Investigations of Ruthenium Deposited onto Representative Inner Surfaces of Nuclear Reactor Containment Buildings

International audienceIn the case of a hypothetical severe accident in a nuclear power plant, interactions of gaseous RuO4 with reactor containment building surfaces (stainless steel and epoxy paint) could possibly lead to a black Ru-containing deposit on these surfaces. Some scenarios include the possibility of formation of highly radiotoxic RuO4(g) by the interactions of these deposits with the oxidising medium induced by air radiolysis, in the reactor containment building, and consequently dispersion of this species. Therefore, the accurate determination of the chemical nature of ruthenium in the deposits is of the high importance for safety studies. An experiment was designed to model the interactions of RuO4(g) with samples of stainless steel and of steel covered with epoxy paint. Then, these deposits have been carefully characterised by scanning electron microscopy (SEM/EDS), electron probe microanalysis (EPMA) and X-ray photoelectron spectroscopy (XPS). The analysis by XPS of Ru deposits formed by interaction of RuO4(g), revealed that the ruthenium is likely to be in the IV oxidation state, as the shapes of the Ru3d core levels are very similar with those observed on the RuO2,xH2O reference powder sample. The analysis of O1s peaks indicates a large component attributed to the hydroxyl functional groups. From these results, it was concluded that Ru was present on the surface of the deposits as an oxyhydroxide of Ru(IV). It has also to be pointed out that the presence of “pure” RuO2, or of a thin layer of RuO3 or Ru2O5, coming from the decomposition of RuO4 on the surface of samples of stainless steel and epoxy paint, could be ruled out. These findings will be used for further investigations of the possible revolatilisation phenomena induced by ozone

High-field and high-temperature magnetoresistance reveals the superconducting behaviour of the stacking faults in multilayer graphene

In spite of 40 years of experimental studies and several theoretical proposals, an overall interpretation of the complex behavior of the magnetoresistance (MR) of multilayer graphene, i.e. graphite, at high fields ($B \lesssim 70~$T) and in a broad temperature range is still lacking. Part of the complexity is due to the contribution of stacking faults (SFs), which most of thick enough multilayer graphene samples have. We propose a procedure that allows us to extract the SF contribution to the MR we have measured at 0.48~K $\leq T \leq$ 250~K and 0~T$\leq B \lesssim$ 65~T. We found that the MR behavior of part of the SFs is similar to that of granular superconductors with a superconducting critical temperature $T_c \sim$ 350~K, in agreement with recent publications. The measurements were done on a multilayer graphene TEM lamella, contacting the edges of the two-dimensional SFs.Comment: 8 pages, 5 figure

Actitudes hacia desmovilizados del conflicto armado en Colombia por parte de civiles y militares en uso de buen retiro, residentes en Bogotá

Resumen:  Objetivo: establecer las actitudes hacia los desmovilizados de la guerrilla por parte de civiles y militares en uso de buen retiro de Bogotá. Método: el estudio tuvo un alcance descriptivo, con un método de comparación de grupos, se seleccionó una muestra de 120 participantes, bajo un procedimiento no probabilístico, con edades entre los 40 a 60 años distribuidos en 60 militares en uso de buen retiro y 60 civiles, residentes en la ciudad de Bogotá, a quienes se les aplicó el cuestionario de Actitudes hacia Desmovilizados de la Guerrilla. Resultados:  se encontró que el 84.1% de los participantes presentan una actitud positiva o neutra, y estadísticos de comparación superiores al 0,05, lo que permite afirmar en discusión que ambos grupos presentan actitud positiva hacia los desmovilizados de la guerrilla, y que no se encuentran diferencias significativas entre civiles y militares en uso de buen retiro, residentes en Bogotá. Conclusión: se afirma que el tener una actitud positiva, neutra o negativa no depende de la diferencia entre ser militar o civil.  Abstract Objective: This study aims to establish civilian and military retired officials’ attitudes towards guerrillas demobilization from Bogotá (Col), for a well retirement. Method: This study scope was descriptive, it was conducted, comparing groups, 120 selected participants, between 40 and 60 years, based on a not probabilistic procedure distributed as follows: 60 military retired officials and 60 civilians residents from Bogotá; a questionnaire related to attitudes toward demobilized population of armed conflict, was used. Results: 84.1 % of participants show a positive or neutral attitude, and statistical comparison higher than 0.05; this result, allows to say that both groups have a positive attitude towards demobilized guerrillas and there are not significant differences between civilian and military retired officials, residents in Bogotá. Conclusion: As a conclusion, a positive, neutral or negative attitude does not depend on the difference between being military retired official or civilian

Identification, characterization, and gene expression analysis of nucleotide binding site (NB)-type resistance gene homologues in switchgrass

Abstract Background Switchgrass (Panicum virgatum L.) is a warm-season perennial grass that can be used as a second generation bioenergy crop. However, foliar fungal pathogens, like switchgrass rust, have the potential to significantly reduce switchgrass biomass yield. Despite its importance as a prominent bioenergy crop, a genome-wide comprehensive analysis of NB-LRR disease resistance genes has yet to be performed in switchgrass. Results In this study, we used a homology-based computational approach to identify 1011 potential NB-LRR resistance gene homologs (RGHs) in the switchgrass genome (v 1.1). In addition, we identified 40 RGHs that potentially contain unique domains including major sperm protein domain, jacalin-like binding domain, calmodulin-like binding, and thioredoxin. RNA-sequencing analysis of leaf tissue from ‘Alamo’, a rust-resistant switchgrass cultivar, and ‘Dacotah’, a rust-susceptible switchgrass cultivar, identified 2634 high quality variants in the RGHs between the two cultivars. RNA-sequencing data from field-grown cultivar ‘Summer’ plants indicated that the expression of some of these RGHs was developmentally regulated. Conclusions Our results provide useful insight into the molecular structure, distribution, and expression patterns of members of the NB-LRR gene family in switchgrass. These results also provide a foundation for future work aimed at elucidating the molecular mechanisms underlying disease resistance in this important bioenergy crop

OceanGliders Oxygen SOP

The live version of this SOP is on the Ocean Gliders community in GITHUB. The home repository of this publication is in the Ocean Best Practices Repository. This standard operating procedure (SOP) document for dissolved oxygen (DO) aims to guide the user through the steps necessary to collect good quality dissolved oxygen data using ocean gliders for both real time and post deployment data streams

Legal linked data ecosystems and the rule of law

This chapter introduces the notions of meta-rule of law and socio-legal ecosystems to both foster and regulate linked democracy. It explores the way of stimulating innovative regulations and building a regulatory quadrant for the rule of law. The chapter summarises briefly (i) the notions of responsive, better and smart regulation; (ii) requirements for legal interchange languages (legal interoperability); (iii) and cognitive ecology approaches. It shows how the protections of the substantive rule of law can be embedded into the semantic languages of the web of data and reflects on the conditions that make possible their enactment and implementation as a socio-legal ecosystem. The chapter suggests in the end a reusable multi-levelled meta-model and four notions of legal validity: positive, composite, formal, and ecological