Uso de tecnologías abiertas (Processing) en el desarrollo de interfaces avanzadas de visualización y acceso de datos : Estudio del caso Organic.Edunet

El artículo muestra, a través del estudio del caso del buscador semántico del portal Organic.Edunet, cómo el uso de tecnologías cerradas en la creación de interfaces avanzadas de visualización de datos impide su desarrollo y evolución. En el artículo se mostrará también cómo, combinado con técnicas para la medición y valoración de la usabilidad de las aplicaciones, el uso de tecnologías abiertas permite detectar los problemas del interface, proponer soluciones o alternativas, e implementarlas rápidamente.

Evaluation of work-related volatile organic compounds (VOCs) exposition in automotive painting cabins industrial cleanings

Automotive painting cabins are cleaned with several solvents, being great part of them mixtures of volatile organic compounds (VOCs), where the three xylene isomers are the most important constituents. To evaluate the work-related exposition of the cleaners that use these mixtures of solvents, xylenes have been determined in the working ambient air as well as its metabolite, o-m-p-methyl hippuric acid, has been analysed in urine to establish the dermal and respiratory exposition. This evaluation has been done in order to assess the occupational exposure to VOCs and to know the working conditions of the cleaners, but also to evaluate the effectiveness of personal protective equipment (PPE), the engineering control and the work practices.The xylenes have been chosen as indicators of exposition because they are the main components in the cleaning solvents used, with a level of concentration between 50% and 85%.The Xylenes have an occupational exposure limit (8 h TWA) of 50 ppm (221 mg/m3) and a short-term exposure limit (STEL) of 100 ppm (442 mg/m3). On the other hand, the biological exposure index (BEI) for xylenes is the sum of the total methyl hippuric acids in urine at the end of the work-shift, being the value 1500 mg/g creatinine.

Basis set and electron correlation effects on initial convergence for vibrational nonlinear optical properties of conjugated organic molecules

The level of ab initio theory which is necessary to compute reliable values for the static and dynamic (hyper)polarizabilities of three medium size π-conjugated organic nonlinear optical (NLO) molecules is investigated. With the employment of field-induced coordinates in combination with a finite field procedure, the calculations were made possible. It is stated that to obtain reasonable values for the various individual contributions to the (hyper)polarizability, it is necessary to include electron correlation. Based on the results, the convergence of the usual perturbation treatment for vibrational anharmonicity was examined

Structural characterization of laser-treated Cr3C2-NiCr coatings

The interconnected porosity of the Cr3C2-NiCr coatings obtained by high-velocity oxy fuel spraying is detrimental in corrosion and wear resistance applications. Laser treatments allow sealing of their surfaces through melting and resolidification of a thin superficial layer. A Nd:YAG laser beam was used to irradiate Cr3C2-NiCr coatings either in the continuous wave mode or at different repetition rates in the pulsed one. Results indicated that high peak and low mean laser irradiances are not good, since samples presented deep grooves and an extensive crack network. At low peak and higher mean laser irradiances the surface was molten, and only a few shallow cracks were observed. The interconnected porosity was completely eliminated in a layer up to 80 m thick, formed by large Cr7C3 grains imbedded in a NiCr matrix.

Hydroxyapatite coatings grown by pulsed laser deposition with a beam of 355 nm wavelength

Calcium phosphate coatings, obtained at different deposition rates by pulsed laser deposition with a Nd:YAG laser beam of 355-nm wavelength, were studied. The deposition rate was changed from 0.043 to 1.16 /shot by modification of only the ablated area, maintaining the local fluence constant to perform the ablation process in similar local conditions. Characterization of the coatings was performed by scanning electron microscopy, x-ray diffractometry, and infrared, micro-Raman, and x-ray photoelectron spectroscopy. The coatings showed a compact surface morphology formed by glassy gains with some droplets on them. Only hydroxyapatite (HA) and alpha-tricalcium phosphate (alpha-TCP) peaks were found in the x-ray diffractograms. The relative content of alpha TCP diminished with decreasing deposition rates, and only HA peaks were found for the lowest rate. The origin of alpha TCP is discussed.

Structural characterization of laser-treated Cr3C2-NiCr coatings

The interconnected porosity of the Cr3C2-NiCr coatings obtained by high-velocity oxy fuel spraying is detrimental in corrosion and wear resistance applications. Laser treatments allow sealing of their surfaces through melting and resolidification of a thin superficial layer. A Nd:YAG laser beam was used to irradiate Cr3C2-NiCr coatings either in the continuous wave mode or at different repetition rates in the pulsed one. Results indicated that high peak and low mean laser irradiances are not good, since samples presented deep grooves and an extensive crack network. At low peak and higher mean laser irradiances the surface was molten, and only a few shallow cracks were observed. The interconnected porosity was completely eliminated in a layer up to 80 m thick, formed by large Cr7C3 grains imbedded in a NiCr matrix.

Roughness and light scattering of ion-beam-sputtered fluoride coatings for 193 nm

Scattering characteristics of multilayer fluoride coatings for 193 nm deposited by ion beam sputtering and the related interfacial roughnesses are investigated. Quarter- and half-wave stacks of MgF2 and LaF3 with increasing thickness are deposited onto CaF2 and fused silica and are systematically characterized. Roughness measurements carried out by atomic force microscopy reveal the evolution of the power spectral densities of the interfaces with coating thickness. Backward-scattering measurements are presented, and the results are compared with theoretical predictions that use different models for the statistical correlation of interfacial roughnesses.

Procedure to characterize microroughness of optical thin films: application to ion-beam-sputtered vacuum-ultraviolet coatings

A method for characterizing the microroughness of samples in optical coating technology is developed. Measurements over different spatial-frequency ranges are composed into a single power spectral density (PSD) covering a large bandwidth. This is followed by the extraction of characteristic parameters through fitting of the PSD to a suitable combination of theoretical models. The method allows us to combine microroughness measurements performed with different techniques, and the fitting procedure can be adapted to any behavior of a combined PSD. The method has been applied to a set of ion-beam-sputtered fluoride vacuum-UV coatings with increasing number of alternative low- and high-index layers. Conclusions about roughness development and microstructural growth are drawn.

Ultraviolet optical and microstructural properties of MgF2 and LaF3 coatings deposited by ion-beam sputtering and boat and electron-beam evaporation

Single layers of MgF2 and LaF3 were deposited upon superpolished fused-silica and CaF2 substrates by ion-beam sputtering (IBS) as well as by boat and electron beam (e-beam) evaporation and were characterized by a variety of complementary analytical techniques. Besides undergoing photometric and ellipsometric inspection, the samples were investigated at 193 and 633 nm by an optical scatter measurement facility. The structural properties were assessed with atomic-force microscopy, x-ray diffraction, TEM techniques that involved conventional thinning methods for the layers. For measurement of mechanical stress in the coatings, special silicon substrates were coated and analyzed. The dispersion behavior of both deposition materials, which was determined on the basis of various independent photometric measurements and data reduction techniques, is in good agreement with that published in the literature and with the bulk properties of the materials. The refractive indices of the MgF2 coatings ranged from 1.415 to 1.440 for the wavelength of the ArF excimer laser (193 nm) and from 1.435 to 1.465 for the wavelength of the F2 excimer laser (157 nm). For single layers of LaF3 the refractive indices extended from 1.67 to 1.70 at 193 nm to ~1.80 at 157 nm. The IBS process achieves the best homogeneity and the lowest surface roughness values (close to 1 nmrms) of the processes compared in the joint experiment. In contrast to MgF2 boat and e-beam evaporated coatings, which exhibit tensile mechanical stress ranging from 300 to 400 MPa, IBS coatings exhibit high compressive stress of as much as 910 MPa. A similar tendency was found for coating stress in LaF3 single layers. Experimental results are discussed with respect to the microstructural and compositional properties as well as to the surface topography of the coatings.

Inhibition of glutathione efflux in the perfused rat liver and isolated hepatocytes by organic anions and bilirubin. Kinetics, sidedness, and molecular forms.

Using isolated, in situ, single-pass perfused rat livers, incubations of freshly isolated hepatocytes, and sinusoidal membrane-enriched vesicles, we and others have shown the saturability of transport (efflux) of hepatic glutathione (GSH). These observations have implicated a carrier mechanism. Our present studies were designed to provide further evidence in support of a carrier mechanism for hepatic GSH efflux by demonstrating competition by liver-specific ligands which are taken up by hepatocytes. Perfusing livers with different substances, we found that: (a) sulfobromophthalein-GSH (BSP-GSH) had a dose-dependent and fully reversible inhibitory effect on GSH efflux, while GSH alone did not have any effect; (b) taurocholate had no inhibitory effect; (c) all of the organic anions studied, i.e., BSP, rose bengal, indocyanine green, and unconjugated bilirubin (UCB), manifested potent, dose-dependent inhibitory effects, with absence of toxic effects and complete reversibility of inhibition in the case of UCB. The inhibitory effects of UCB could be overcome partially by raising (CoCl2-induced) hepatic GSH concentration. Because of the physiological importance of UCB, we conducted a detailed study of its inhibitory kinetics in the isolated hepatocyte model in the range of circulating concentrations of UCB. Studies with Cl- -free media, to inhibit the uptake of UCB by hepatocytes, showed that the inhibition of GSH efflux by UCB is apparently from inside the cell. This point was confirmed by showing that the inhibition is overcome only when bilirubin-loaded cells are cleared of bilirubin (incubation with 5% bovine serum albumin). Using Gunn rat hepatocytes and purified bilirubin mono- and diglucuronides, we found that both UCB and glucuronide forms of bilirubin inhibit GSH efflux in a dose-dependent manner. We conclude that the organic anions, although taken up by a mechanism independent of GSH, may competitively inhibit the carrier for GSH efflux from inside the hepatocyte.

Nanomechanical properties of molecular organic thin films

Using atomic force microscopy we have studied the nanomechanical response to nanoindentations of surfaces of highly oriented molecular organic thin films (thickness¿1000¿nm). The Young¿s modulus E can be estimated from the elastic deformation using Hertzian mechanics. For the quasi-one-dimensional metal tetrathiafulvalene tetracyanoquinodimethane E~20¿GPa and for the ¿ phase of the p-nitrophenyl nitronyl nitroxide radical E~2GPa. Above a few GPa, the surfaces deform plastically as evidenced by discrete discontinuities in the indentation curves associated to molecular layers being expelled by the penetrating tip.

High-Temperature magnetic ordering in a new organic magnet

Magnetization, heat capacity, and neutron diffraction experiments on the beta-phase of the dithiadiazolyl radical, p-NC.C6F4.CNSSN., provide conclusive evidence that this system exhibits noncollinear antiferromagnetism at 35.5 K, an unprecedented temperature for an organic radical. On the basis of magnetization and powder neutron diffraction results, coupled with theoretical calculations of the spin distribution within the molecule, a magnetic structure for this compound is proposed in which the interactions propagate through S . . .N contacts.

Fifth-order cyclicity and organic matter contents relationship (Lower Eocene, Pyrenees)

The Upper Limestone Member of the Corones Formation of the Spanish Pyrenees consists of various units (Lower and Upper Foraminifera Units, Shale Unit, Cherty-ostracode Unit, Ostracode Unit and Chara-ostracode Unit) and offers strong facies and lateral thickness (20 to 80 m) variations. Detailed facies analyses, fifth-order cycles and organic geochemical determinations in the central domain of the Corones platform carbonates (Cherty-ostracode Unit), lower Eocene in age, were carried out to establish a case of close relationship between variations in organic matter productivity and cyclicity with annual period. The Cherty-ostracode Unit displays a continuous and pervasive fifth-order cyclicity, represented by 5 cycles. Each cycle consists of a lower part (mollusc facies) and an upper part (laminated ostracode facies). The calculated fifth-order cycle period ranges from about 17,000 to 28,000 years, which falls within the Milankovitch Band. Variations in organic matter content related to these carbonate cycles have been established. The lower mollusc facies members show a low organic carbon content and Hydrogen Index (HI) below 0.6% in weight and 261, respectively. By contrast, the upper laminated ostracode facies members show high organic carbon contents (up to 2% in weight) and high HI (between 164 and 373), and are also characterized by important silicification processes (the content in chert is up to 30%). The organic geochemistry resulting from these organic rich levels reflects a contribution of algal marine input.