Homo- and Heteroleptic Copper(I) Complexes with Diazabutadiene Ligands: Synthesis, Solution- and Solid-State Structural Studies

The preparation of novel copper(I) complexes of diazabutadiene (DAB) ligands with aliphatic backbones is reported. [Cu(DABR)2](BF4), [Cu(DABR)(NCMe)2](BF4) and [CuCl(DABR)] are easily synthesised and air-stable. These complexes, which remain scarce in the literature, have been fully characterised, and their behaviour both in the solid state as well as in solution has been studied by means of X-ray crystallography, NMR and UV/Vis spectroscopy

Novel approaches to determine residual stresses by ultramicroindentation techniques: application to sand blasted austenitic stainless steel

This research addresses the determination of residual stresses in sandblasted austenitic steel by ultramicroindentation techniques using a sharp indenter, whose sensitivity to residual stress effects is said to be inferior to that for spherical ones. We propose the introduction of an angular correction in the model of Wang et al. that relates variations in the maximum load to the presence of residual stresses. Likewise, the contribution to hardness of grain size refinement and work hardening, developed as a consequence of the severe plastic deformation during blasting, is determined to avoid overestimation of the residual stresses. Measurements were performed on polished cross sections along a length of several microns, thus obtaining a profile of the residual stresses. Results show a good agreement with those obtained by synchrotron radiation on the same specimens, which validates the method and demonstrates that microindentation using sharp indenters may be sensitive to the residual stress effect.Peer Reviewe

Quantitative determination of modal content and morphological properties of coal sulphides by digital image analysis as a tool to check their flotation behaviour

An efficient depression of coal sulphides in the flotation process means a healthier environment and may be essential for the sustainability of a coal operation. Nitric and ferric oxidative pre-treatment of coal pyrite have been tested to improve pyrite depression, and the results are compared with those from the process of raw, not pre-treated coal. The removal indexes point to nitric pre-treatment as the best, but depression is still low. The microscopic study of feed and products, coupled to Digital Image Analysis (DIA) in all the cases, provide important clues to understand the behaviour of pyrite, which can be related to quantitative parameters, such as the exposition ratio (ER), and to qualified interpretation of the textures. Pyrite shows in the first float an unexpected hydrophobic behaviour, which is due to its occurrence as framboids, or porous particles which may be intergrown with organic matter and behave as coal. In general, the flotation results can be predicted from the DIA-data, e.g. depression of liberated pyrite into the tailings, increased by oxidative pre-treatments by 300% (ferric) or by > 400% (nitric); or concentration of middlings with lower pyrite ER in the floats. DIA is an efficient tool to obtain some important quantitative informations which otherwise would be inaccessible (e.g. the morphological data on > 1,000,000 pyrite particles for this study), and its use should be enhanced to check ore processing

“Desafíos y proyección de una viticultura joven de escala reducida: Tannat del Uruguay”

El objetivo principal de esta presentación es reflexionar – a partir de nuestra investigación académica- sobre el tema que nos convoca “Desafíos de la producción y el mercado” desde una vitivinicultura caracterizada por ser joven (desde 1870), de escala reducida (6.562 has. totales, 1.708 has. de Tannat) y con gran identidad (“Uruguay, país del Tannat”). Partimos de interpretar los desafíos como los retos o acciones para competir en la producción y en el mercado global, por lo tanto, se trata de planificar y proyectar para lo que vendrá desde una enología respetuosa de los “caracteres naturales y esenciales del vino”como lo propone el título de esta sección y que en este caso serán las características de nuestro vino Tannat. Por lo tanto, el desafío de la enología para el tannat de Uruguay sería la adecuación continua e integral de lo que se produce y ofrece al mercado; calidad del proceso, calidad de la información, calidad de los productos y comprobaciones que las certifiquen

Cryopreservation of Brown Bear Skin Biopsies

Genetic resource banks and assisted reproductive technologies support the conservation of endangered or threatened species. In this study we assessed two procedures to cryopreserve skin biopsies from live brown bears. Skin biopsies were taken from six live, anesthetized brown bears. Single biopsies (n = 3) of each animal were cut into small pieces and assigned to one of the three experimental groups: freezing, vitrification, or untreated fresh. There were no differences on cell attachment. However, both freezing and fresh culture allowed for higher cell proliferation (p < 0.05) and less days to reach 70% to 80% confluence (p < 0.03) than vitrification. Skin biopsies from brown bears can be preserved long term, allowing fibroblasts to proliferate in culture. Slow freezing was effective to cryopreserve skin biopsies from brown bears

Antimicrobial susceptibility of Salmonella isolated pig carriers

Ninety-six Salmonella isolates from healthy carrier pigs were obtained from a survey in pig farms of Catalonia (Spain). Isolates were serotyped and examined for their antimicrobial susceptibility against a panel of 18 antimicrobial agents. Only isolates having different phenotypic and antimicrobial susceptibility characteristics were considered. With this restriction, we considered to have 62 different strains belonging to 17 serotypes. The most common serotype was Anatum (16.1 %) followed by Rissen (14.5 %), Typhimurium (11.3 %), Derby (9.7 %), Tilburg (8.1 %), Goldcoast (8.1 %) and Typhimurium variant 4,5,12:i:- (6.5 %). Others 10 serotypes were also isolated less than three times each. Antimicrobial susceptibility analysis showed that the highest level of resistance was against tetracycline (68.8 %). Sixty-two percent of the strains showed resistance to three or more antimicrobial agents and 46% were resistant to five or more drugs. The maximum number of compounds to which two strains were resistant was 10 (corresponding to a 4,5,12:i:- strain). None of the strains was resistant to colistin or ceftriaxone and 12 strains were susceptible to all antimicrobial agents tested

Column-integrated aerosol microphysical properties from AERONET Sun photometer over southwestern Spain

The aim of the present work is to carry out a detailed analysis of columnar microphysical properties obtained from Cimel sun-photometer measurements in the Southwest of Spain within the frame of the Aerosol Robotic Network (AERONET) – Iberian Network for aerosol measurements (RIMA). AERONET level 2 inversion products are analysed, in particular the particle size distribution together with their associated microphysical parameters for both fine and coarse modes: volume concentration, effective radius and the fine mode volume fraction. This work complements previous works based on aerosol optical depth (AOD) and the Ångström exponent (AE) for a global characterization of atmospheric aerosol in this area of southwestern Spain.Financial support from the Spanish MICINN (projects of ref. CGL2008-05939-CO3-01/CLI and CGL2009- 09740 and “Acci´on Complementaria” CGL2010-09480-E) are gratefully acknowledged

Error source in AOD retrieval from filter radiometer data in the UV due to filter band function

The filter band function of filter radiometers is frequently used in AOD retrieval to improve the accuracy of the Rayleigh and gaseous absorption contributions to the total optical depth. These contributions to the total optical thickness are overestimated when the band-pass filter curve used in the computation exceeds the lower limit of the detector response range (around 320 nm). It can be the case for some typical band-pass filters used in the ultraviolet region (e.g. 340 or 380 nm). This error can involve a strong impact on the aerosol optical depth accuracy, underestimating its value. Errors as large as 0.047 in the evaluation of ozone optical depth at 340 nm, and 0.009 in the Rayleigh optical depth were found, leading to final errors of 50–100% in the AOD for remote locations, like Polar regions or high mountains. To avoid this significant error, the detector spectral response must be taken into account in the computations. Further, it is recommended to discard the filter band-pass function when the transmittance falls below 1% of its maximum value at the central wavelength