Generalitat de Catalonia

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Barcelona, Spain
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Vilarrubias P.,Generalitat de Catalonia
Canadian Journal of Chemistry | Year: 2017

The compound Cl-W(Mes)3-N=N-W(Mes)3-Cl can polymerize, giving large inorganic pi systems containing N2 and W(Mes)3, where Mes = mesityl. Some of these compounds have been studied in the present paper using B3LYP functional. A description of the molecular orbitals from the pi system is given, explaining the role of the mesityl groups, the terminal chlorines, and the d atomic orbitals from W in the whole conjugated system. Other data such as bond order, atomic partial charges, or geometry are studied. These compounds are also compared with some hypothetical derivatives.

Compounds with double bonds Terp-E=E′-Terp (E, E'=P, As, Sb or Bi; Terp=-C6H3-2,6 (C6H5)2) have been studied using DFT. These compounds have been used as a model for other compounds with larger substituents. Some bands of its electronic spectroscopy have been calculated using TDDFT, and the results show high correlation with experimental data, when available. In Bi-containing compounds, the origin of some weak bands in the calculated spectra and also in experimental data is unclear. An assignation of these bands is suggested, wedding the experimental data with calculated and theoretical results. These bands could be weak singlet–triplet transitions, partially allowed by spin-orbit coupling only in Bi-containing compounds. A theoretical estimation of the energy of these bands is achieved using CASSCF and MR-MP2. © 2017 Informa UK Limited, trading as Taylor & Francis Group

Vilarrubias P.,Generalitat de Catalonia
Canadian Journal of Chemistry | Year: 2015

Ten compounds of dimolybdenum are studied using density functional theory and time-dependent density functional theory. The energy of the strongest symmetry-allowed bands is calculated. The results are then compared with experimental data, when available. The PW91 functional gives results for geometry and for the energy of the δ→δ∗ band that show good agreement with experimental data. However, the B3LYP functional gives more realistic values for the whole spectrum when the results are compared with experimental data. Finally, the different values of energy of these bands are explained analyzing the molecular orbitals involved in these transitions. Some ligands can act as an unsaturated system in conjugation with the delta bond, modifying the energies of the electronic transitions. © 2016 Published by NRC Research Press.

Sarda R.,CSIC - Center for Advanced Studies of Blanes | Rossi S.,Autonomous University of Barcelona | Marti X.,Generalitat de Catalonia | Gili J.M.,CSIC - Institute of Marine Sciences
Scientia Marina | Year: 2012

The marine benthic cartography of the Cap de Creus and surrounding areas (NW Mediterranean Sea) was obtained by combining classical grabbing methods with more recent imaging methods based on a remotely operated vehicle. The goals of this particular survey can be summarized as follows: 1) to chart the benthic communities (and the area of each one); 2) to evaluate the benthic diversity of the areas; 3) to produce visual documentation of the distributions of the benthic organisms; 4) to identify human-induced pressures on the benthic environment; 5) to make recommendations for future management based on the visual assessment; and 6) to set up a new methodology for making large biocenosis maps that would help to manage marine protected and non-protected areas. The marine environment off the Alt Empordà County was shown to have a very rich diversity of benthic habitats. Twenty community categories were identified from videos and grabs. Though benthic habitats mostly located inside a marine protected area were assessed, man-made objects were seen in 10% of the analyzed minutes filmed. The study led to a comprehensive review of the main biotope systems of this coastal area, as well as their environmental condition, and this will be an essential element for their future management.

Gil E.,Polytechnic University of Catalonia | Llorens J.,Polytechnic University of Catalonia | Landers A.,Cornell University | Llop J.,Polytechnic University of Catalonia | Giralt L.,Generalitat de Catalonia
European Journal of Agronomy | Year: 2011

Dose expression and volume rate are key questions for spray application in orchard and vineyard plantations. Crop characteristics seem to be one of the most important factors to determine the optimal value, but parameters as the leaf area, canopy volume, and canopy density are difficult to quantify. dosaviña, a decision support system, has been developed as a tool to calculate the optimal volume rate for spray applications in vineyards. The method is based on achieving the optimal coverage (impactscm-2) according to the characteristics of the crop canopy, and includes the establishment of an efficiency factor that depends on aspects such as the type of sprayer used, nozzle type and size, operational parameters, and weather conditions. Field tests, in order to evaluate the interest in and functionality of the dosaviña computer program, were arranged for different wine grape varieties in New York State (USA) and Lleida (Spain), with a wide spectrum of wine varieties (Baco, Riesling, Vignoles, Merlot, and Cabernet Sauvignon), sprayers, and working conditions. Deposition, uniformity, and control of different diseases (powdery mildew, Botrytis bunch rot, and grape black rot) were evaluated at different crop stages, by comparing the volume rate applied according to dosaviña with the conventional rate most generally used by farmers. The volume rate was reduced by an average 39.9% for dosaviña, with similar or even higher values of deposition and uniformity. The resulting reduction in pesticide use (average 53%) did not present any difference in disease control for the selected varieties. Methodologies based on coverage and leaf area, as prescribed by dosaviña, seem to be an effective alternative approach to determine the most adequate volume rate according to the canopy structure, with the consequent diminution of pesticide use and the increase of environmentally friendly practices. © 2011 Elsevier B.V.

The electronic spectra of 12 isoelectronic binuclear decacarbonyls MM′(CO)10 have been calculated, using time-dependent density functional theory (TD-DFT). The geometry has been optimised using the B3LYP functional. The energy of some well-known bands is calculated with the same functional for Mn2(CO)10 and other compounds as a test, using the same functional. The calculated values for the energy and the oscillator strength are in good fitting with experimental and reference data, and they show very small dependence on the basis. Then, the same calculation has been carried out for all the compounds up to 150 states. The strongest calculated transitions are summarised and assigned. © 2016 Taylor & Francis

The electronic spectra of ten binuclear decacarbonyls MM′(CO)10 has been calculated using TD-DFT method. The geometry has been optimized using the B3LYP functional. The energy of some well known bands is calculated for Mn2(CO)10 and other compounds as a test. The calculated values for the energy and the oscillator strength are in good fitting with experimental and reference data, and they show very small dependence on the basis. Then, the same calculation has been carried out for all the compounds up to 150 states. The strongest calculated transitions are summarized and assigned.

Alier M.,CSIC - Institute of Environmental Assessment And Water Research | Felipe M.,Loughborough University | Hernandez I.,Generalitat de Catalonia | Tauler R.,CSIC - Institute of Environmental Assessment And Water Research
Analytical and Bioanalytical Chemistry | Year: 2011

Multiway and multiset data analysis extensions of the multivariate curve resolution alternating least squares (MCR-ALS) method are proposed for the investigation of the temporal distribution of the pollution by nitric oxide (NO) and ozone (O3) in one sampling station in the urban centre of Barcelona (Catalonia, Spain), during the years 2000-2006. Different specific studies were performed considering the annual and pluriannual contamination by these two contaminants, individually or in combination using different data matrix augmentation strategies and multiway and multiset data analysis models. Daily, hourly and annual profiles were estimated describing different patterns and summarising the main contamination processes. The daily and night trends found were mainly attributed to traffic and photochemical processes favoured by light radiation. Moreover, winter-summer seasonal trends were also clearly detected and their changes over different years assessed. The extension MCR-ALS method to multiset data analysis using different constraints like non-negativity, trilinearity and interaction among components is confirmed to be a powerful method to improve the interpretability of the different contamination patterns in atmospheric contamination studies. © Springer-Verlag 2010.

Muniz I.,Autonomous University of Barcelona | Calatayud D.,Polytechnic University of Catalonia | Dobano R.,Generalitat De Catalonia
Landscape and Urban Planning | Year: 2013

The compensation hypothesis poses the possibility that individuals who live in dense urban centres have a greater propensity to have a second residence and/or to travel more frequently to more distant destinations on the weekends and vacations than individuals who live in zones that are not so dense. Given this context, the net effect of density in environmental terms is not clear. In this study, we check the compensation hypothesis in the Barcelona Metropolitan Area using the ecological footprint of mobility and housing as global environmental impact indicator. The results strongly reject the compensation hypothesis, although they do detect the existence of a maximum level of density beyond which a positive impact is exerted. © 2013 Elsevier B.V..

Castell C.,Generalitat de Catalonia
Revista de enfermería (Barcelona, Spain) | Year: 2010

Diabetes is a chronic metabolic disorder cause by an absolute or relative insulin deficit. Diabetes is characterized by the presence of hyperglycemia and by metabolic alterations regarding all the immediate principle nutrients: carbohydrates, lipids and proteins. Diabetes causes high morbidity and mortality derived by chronic micro-vascular complications such as retinopathy, nephropathy, or neuropathy and macro-vascular complications such as ischemic cardiac problems, cerebral vascular accidents, peripheral vascular disorders. The layman's belief that diabetes occurred only due to hereditary factors has been changing as numerous studies have shown that diabetes deals with a group of heterogenous disorders which develop as a combination of hereditary and environmental factors.

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