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 MgF(2) and LaF(3) with increasing thickness are deposited onto CaF(2) 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.     

Neural computation as adaptive association process in cortical sensorial maps

In this work, the different computational paradigms used in Artificial Intelligence (AI) and Autonomous Robotics are revised in the context of the reactive and situated paradigm. In particular, a Neural Computational paradigm based on perceptual association maps is revised. We explore the Singer hypothesis about the evidence of the same neural mechanism known from retinotopic projections. Finally, the implications of this computational paradigm with maps in the context of the definition, design, building and evaluation of neuroprosthesis are discussed.     

DRYING CHARACTERISTICS OF THE HAZELNUT

Abstract

Equilibrium moisture content isotherms for Spanish hazelnut (Corylus avellana L.) at different temperatures (30°C-80°C) were determined using static gravimetric method. Thin layer drying experiments were done with forced air circulation and were conducted with different operating conditions to determine the drying characteristics of hazelnuts. The effect of air temperature (30°C-70°C), air velocity (0.5 m/s - 2 m/s) and drying bed loading density (50 kg/m² - 150 kg/m²) on drying of unshelled and shelled hazelnuts was studied. Six mathematical models were used to fit the experimental equilibrium moisture content data, from which the G.A.B. model was found to give the best fit. Diffusion coefficients were determined by fitting experimental thin-layer drying curves to the Fick's diffusion model. Variation of the effective diffusion coefficient with temperature was of the Arrhenius type. The Page equation was found to describe adequately the thin layer drying of hazelnut. Page equation drying parameters k and n were correlated with air temperature and relative humidity.     

Design and optimization of an extrusion die for the production of wood–plastic composite profiles

In this work, the optimization of an extrusion die designed for the production of a wood–plastic composite (WPC) decking profile is investigated. The optimization was performed with the help of numerical tools, more precisely, by solving the continuity and momentum conservation equations that govern such flow, and aiming to balance properly the flow distribution at the extrusion die flow channel outlet. To capture the rheological behavior of the material, we used a Bird‐Carreau model with parameters obtained from a fit to the (shear viscosity versus shear‐rate) experimental data, collected from rheological tests. To yield a balanced output flow, several numerical runs were performed by adjusting the flow restriction at different regions of the flow‐channel parallel zone cross‐section. The simulations were compared with the experimental results and an excellent qualitative agreement was obtained, allowing, in this way, to attain a good balancing of the output flow and emphasizing the advantages of using numerical tools to aid the design of profile extrusion dies. POLYM. ENG. SCI., 55:1849?1855, 2015. © 2014 Society of Plastics Engineers     

Comparing different methods to fix and to dehydrate cells on alginate hydrogel scaffolds using scanning electron microscopy

Scanning electron microscopy (SEM) is commonly used in the analysis of scaffolds morphology, as well as cell attachment, morphology and spreading on to the scaffolds. However, so far a specific methodology to prepare the alginate hydrogel (AH) scaffolds for SEM analysis has not been evaluated. This study compared different methods to fix/dehydrate cells in AH scaffolds for SEM analysis. AH scaffolds were prepared and seeded with NIH/3T3 cell line; fixed with glutaraldehyde, osmium tetroxide, or the freeze drying method and analyzed by SEM. Results demonstrated that the freeze dried method interferes less with cell morphology and density, and preserves the scaffolds structure. The fixation with glutaraldehyde did not affect cells morphology and density; however, the scaffolds morphology was affected in some level. The fixation with osmium tetroxide interfered in the natural structure of cells and scaffold. In conclusion the freeze drying and glutaraldehyde are suitable methods for cell fixation in AH scaffold for SEM, although scaffolds structure seems to be affected by glutaraldehyde. Microsc. Res. Tech. 78:553–561, 2015. © 2015 Wiley Periodicals, Inc.     

An Empirical Approach to Spanish Anaphora Resolution

This paper documents the development of an empirically-basedsystem implemented in Prolog that automatically resolves severalkinds of anaphora in Spanish texts. These are pronominalreferences, surface-count anaphora, one-anaphora and ellipticalzero-subject constructions (i.e., sentences that omit theirpronominal subject). The resolution is based onrepresentations resulting from either partial or full parsing. Thesystem developed can also work on the output of a POStagger or with different dictionaries, without changing thegrammar. This grammar represents the syntactic information of eachlanguage by means of the Slot Unification Grammar formalism. The different kinds of information used for anaphora resolution in full and partial parsing are shown, as wellas evaluation results. The system has been adapted toEnglish texts, obtaining encouraging results that prove that itcan be applied with only a very few refinements to other languagesas well as Spanish and English. In addition, the differencesbetween English and Spanish anaphora are noted.     

The role of the consumer in the reduction of Listeria monocytogenes in lettuces by washing at home

Lettuce is highly appreciated for its nutritional properties; however microbial contamination through the food chain and its raw consumption may jeopardize these known benefits to the diet. The objective of this study was to determine the role of the consumer at the stage of washing at home, in relation to the probability of illness due to the presence of Listeria monocytogenes in lettuce. Survival curves of L. monocytogenes after washing (dipping with and without addition of bleach, and washing under a running tap) were studied. A mathematical model for each washing method was calculated by fitting experimental data. The obtained models were used to estimate the probability of illness after washing at home. Results show that although consumers can only deal with low loads of L. monocytogenes, their role is essential to reduce the normal contamination level of lettuces and ensure their safety.