Degradation of Acid Black 210 by advanced oxidative processes: O3 and O3/UV

Acid Black 210 (AB-210) dye is one of the most black dyes used by the leather industry. In the present work, AB-210 degradation in aqueous solution by ozonation (O₃) and ozonation with ultraviolet (UV) radiation (O₃/UV) was investigated. The effects of pH, initial dye concentration and UV radiation were studied in laboratory scale. Removal was evaluated in terms of residual AB-210 concentration in the treated solution and mineralization efficiency was evaluated by total organic carbon (TOC) analysis. The results indicated that AB-210 is quickly degraded after 15 min but not totally mineralized. It was observed that dye removal of 100% was achieved at pH 3, 7, and 11, while mineralization was found to increase with the pH (55% at pH 11). Concerning UV-C radiation, it enhanced AB-210 degradation at pH 3 but did not reveal any significant effect at pH 7 and 11.     

Nickel molybdate as precursor of HDS catalysts: Effect of phase composition

Sulfided and -NiMoO₄ have been employed as model HDS catalysts, aiming to investigate the effect of phase composition of the precursor mixed oxide on the physicochemical characteristics and activity of the sulfides. Both sulfides are highly amorphous or microcrystalline, and could not be differentiated by means of XRD. The differences in BET area were also found to be minimal. However, it was found by means of TPR that the stable -isomorph is reduced at lower temperatures than the unstable -phase in both the oxidic and sulfided states. Sulfided -NiMoO₄ was found to be a better catalyst for the HDS of thiophene than the sulfided -isomorph. This could be related to the higher stability of the former in H₂, as decomposition of the active, amorphous Ni-Mo-S structures results in less active and more crystalline phases, as found by XRD.     

Games for active ageing,well-being and quality of life: a pilot study

The goal of this study is to identify a set of psychosocial variables and design domains important for game designers to encourage active ageing, well-being and quality of life. Sixty adult learners at four universities of third age were randomly assigned to three groups: the experimental group (G1), who tested firstly a game-based learning platform (GBLP) and then a computer-assisted platform (CAP); the comparison group (G2), who tested firstly the CAP and then the GBLP and the control group (G3) that did not take part in the intervention. Participants were assessed on their health-related well-being and quality of life, using the SF36v2 and WHOQOL-BREF scales before and after each experiment. Findings suggest that there were differences between the group type and their perception on mental health (F(2,57)?=?3.771, p?=?.029) and general health-related well-being (F(2,57)?=?5.231, p?=?.008), in which the GBLP showed improvements relative to the CAP. The environment and mental health were some of the psychosocial domains that should be considered, whereas storytelling, context-aware challenges, game space, immediate feedback, role-playing and social engagement were relevant design domains for these games.     

Harmonic optical microscopy and fluorescence lifetime imaging platform for multimodal imaging

In this work, we proposed and built a multimodal optical setup that extends a commercially available confocal microscope (Olympus VF300) to include nonlinear second harmonic generation (SHG) and third harmonic generation (THG) optical (NLO) microscopy and fluorescence lifetime imaging microscopy (FLIM). We explored all the flexibility offered by this commercial confocal microscope to include the nonlinear microscopy capabilities. The setup allows image acquisition with confocal, brightfield, NLO/multiphoton and FLIM imaging. Simultaneously, two‐photon excited fluorescence (TPEF) and SHG are well established in the biomedical imaging area, because one can use the same ultrafast laser and detectors set to acquire both signals simultaneously. Because the integration with FLIM requires a separated modulus, there are fewer reports of TPEF+SHG+FLIM in the literature. The lack of reports of a TPEF+SHG+THG+FLIM system is mainly due to difficulties with THG because the present NLO laser sources generate THG in an UV wavelength range incompatible with microscope optics. In this article, we report the development of an easy‐to‐operate platform capable to perform two‐photon fluorescence (TPFE), SHG, THG, and FLIM using a single 80 MHz femtosecond Ti:sapphire laser source. We described the modifications over the confocal system necessary to implement this integration and verified the presence of SHG and THG signals by several physical evidences. Finally, we demonstrated the use of this integrated system by acquiring images of vegetables and epithelial cancer biological samples. Microsc. Res. Tech. 2012. © 2012 Wiley Periodicals, Inc.     

Monte Carlo simulation of ion implantation in crystalline SiC

We report first the results of a simulation study of ion implantation in crystalline 6H-SiC. Calculations were performed with a Monte Carlo code modified to account for the hexagonal lattice structure of the material. After an approximate determination of empirical parameters of electronic energy loss, performed by comparison of simulated profiles with experimental data as reported in the literature, a detailed study of the effects of beam-target orientation has been made for a few specific cases. Results have been compared with those of similar simulations made in cubic 3C---SiC, where the same model parameters were used, in order to emphasize differences due to the different crystallographic structure and surface orientation of the two phases. Conditions which originate deep channeling tails in the implanted profiles are identified, as well as conditions suitable to obtain the minimum width profile.     

Analysis and characterization of edible oils by chemometric methods

Chemometric techniques have been used to group samples with similar features as well as to discriminate among experimental data on edible oils. The objective of this study was to provide a simple method for differentiating vegetable oil types and to classify unknown samples using analytical techniques commonly used in the edible oil industry. We used principal component analysis to study the relationship between FA composition, tocopherol levels, CIF (Commission Internationale de l'Eclairage) parameters, and a photometric color index. The total variance in the original data matrix was established mainly by three principal components. Data processing allowed the oil samples to be identified and created a 2-D map as a fingerprint of the oil types. This analysis can be used successfully to differentiate vegetable oil types and classify them as crude or refined oils.     

From Natural Forms to Models

The course presented at the Istituto Statale d’Arte (ISA), a high school for visual and design arts, is a guided tour of the world of forms of seashells. The main goal of this course is to present to the student prevalently scientific methods of interpretation of forms.     

Morphometric Analysis of Transverse Surface of Fractured Maltodextrin Agglomerates

Fracture creates complex surfaces. The aim of this work was to characterize the irregular surface generated in the fracture of maltodextrin thick-agglomerates using gray level intensities and texture features extracted by digital image analysis. Results showed that particle size had no significant effect on texture features and had a significant interaction with load. A 50 N load caused rougher surfaces, while a 500 N load produced smooth surfaces. Obtained values of texture fractal dimension were not higher than 2.23 and were related to image entropy.