Anisotropic conductivity of silver thin films grown on silicon (100) vicinal surfaces

The electrical conductivity between 4 and 300 K of Ag thin films (up to 30 mm grown at room temperature on Si(100) vicinal surfaces has been measured and their morphology imaged with an atomic force microscope. A noticeable anisotropy of the resistivity of the films which is related to the structure of the films has been found)Laboratories du CNRS Departamento de Física Materia Condensada. Universidad Autónoma.Peer reviewe

Quality of two table grape guard cultivars treated with single or dual-phase release SO2 generators

Berries of seeded table grapes (cultivars Napoleón and Aledo) were trimmed in commercial packing houses, inoculated with Botrytis cinerea, packed with single and dual-phase release SO2 pads, and stored for up to four months at 0 ºC and 85±5 % relative humidity. Control grapes with or without inoculation, but without SO2 pads, were stored for up to 2 months. Botrytis cinerea rot (grey mould) limited the shelf-life of Aledo grapes to one month, while a two month shelf-life was established for Napoleón grapes, which suffered from berry splitting, Cladosporium herbarum and Botrytis cinerea rots. Yeasts of the Candida genera and secondary fungi were also identified in fruit suffering sour rot after 2 months at 0oC. No differences in grey mould development in the treatments without SO2 pads with or without inoculation. The native grey mould of these grapes was purified and included as the B. cinerea strain 20248 in the Spanish Type Culture Collection. Storage time, but not SO2 pads, slightly affected fruit quality. During the first month at 0oC, total soluble solids decreased by 1oBrix in 'Áledo' and berry hardness temporarily increased by around 30% in both cultivars. The pads provoked an SO2 taste acceptable for consumption, which was slightly higher in Napoleón than in Aledo grapes. The dual-phase release SO2 pads showed better performance for the long-term storage of grapes than single-release pads (both as regards berry sensory attributes and stem appearance, with lower stem browning). The dual-phase release SO2 pads extended the shelf-life of grapes by around 1 month, depending on the cultivar. Napoleón grapes showed a better potential for longterm storage than Aledo grapes due to thicker and more compact epidermis, thicker cell walls, and different epidermal microstructure including the transition cells between epidermis and the parenchyma

Enthalpies of formation of L12 intermetallics derived from heats of reordering

A new method is proposed for estimating the enthalpies of formation of L12 (fcc-ordered) intermetallics from the heat release measured during ordering of their disordered polymorphs. The method is applied to Cu3Au, Ni3Al, and Ni3Si. The resulting estimates of enthalpies of formation are close to values obtained by high temperature dissolution calorimetry. They also appear to be more precise than estimates based on Miedema's correlations provided that care is taken to account properly for the magnetic and lattice stability contributions to the formation enthalpies in the ordered and disordered states

Fractal surfaces of gold and platinum electrodeposits. Dimensionality determination by scanning tunneling microscopy

The structure of gold and platinum deposits grown on gold and platinum wire cathodes, respectively, by electroreduction of the corresponding oxide layers has been analyzed in terms of surface fractals by measuring the perimeter L and area A of intergranular voids. Perimeter and area were determined from scanning tunneling microscopy (STM) topographic images of the deposit surfaces. Fractal behavior, L ∞ AD'/2 with D'= 1.5 ± 0.1, is found for both platinum and gold deposits. From these measurements, the fractal dimension of the surfaces was 2.5. The D' value of the gold deposits decreases by aging in the electrolyte at 325 K as a consequence of surface diffusion processes.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)Facultad de Ciencias Exacta

Fractal surfaces of gold and platinum electrodeposits. Dimensionality determination by scanning tunneling microscopy

The structure of gold and platinum deposits grown on gold and platinum wire cathodes, respectively, by electroreduction of the corresponding oxide layers has been analyzed in terms of surface fractals by measuring the perimeter L and area A of intergranular voids. Perimeter and area were determined from scanning tunneling microscopy (STM) topographic images of the deposit surfaces. Fractal behavior, L ∞ AD'/2 with D'= 1.5 ± 0.1, is found for both platinum and gold deposits. From these measurements, the fractal dimension of the surfaces was 2.5. The D' value of the gold deposits decreases by aging in the electrolyte at 325 K as a consequence of surface diffusion processes.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)Facultad de Ciencias Exacta

Aerosol optical properties over Europe: an evaluation of the AQMEII Phase 3 simulations against satellite observations

Abstract. The main uncertainties regarding the estimation of changes in the Earth's energy budget are related to the role of atmospheric aerosols. These changes are caused by aerosol–radiation (ARIs) and aerosol–cloud interactions (ACIs), which heavily depend on aerosol properties. Since the 1980s, many international modeling initiatives have studied atmospheric aerosols and their climate effects. Phase 3 of the Air Quality Modelling Evaluation International Initiative (AQMEII) focuses on evaluating and intercomparing regional and linked global/regional modeling systems by collaborating with the Task Force on the Hemispheric Transport of Air Pollution Phase 2 (HTAP2) initiative. Within this framework, the main aim of this work is the assessment of the representation of aerosol optical depth (AOD) and the Ångström exponent (AE) in AQMEII Phase 3 simulations over Europe. The evaluation was made using remote-sensing data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors aboard the Terra and Aqua platforms, and the instruments belonging to the ground-based Aerosol Robotic Network (AERONET) and the Maritime Aerosol Network (MAN). Overall, the skills of AQMEII simulations when representing AOD (mean absolute errors from 0.05 to 0.30) produced lower errors than for the AE (mean absolute errors from 0.30 to 1). Regardless of the models or the emissions used, models were skillful at representing the low and mean AOD values observed (below 0.5). However, high values (around 1.0) were overpredicted for biomass burning episodes, due to an underestimation in the common fires' emissions, and were overestimated for coarse particles – principally desert dust – related to the boundary conditions. Despite this behavior, the spatial and temporal variability of AOD was better represented by all the models than AE variability, which was strongly underestimated in all the simulations. Noticeably, the impact of the model selection when representing aerosol optical properties is higher than the use of different emission inventories. On the other hand, the influence of ARIs and ACIs has a little visible impact compared to the impact of the model used

Anelastic deformation of a Pd40Cu30Ni10P20 bulk metallic glass during nanoindentation

This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.Time-dependent deformation processes during nanoindentation have been investigated on a Pd40Cu30Ni10P20 bulk metallic glass. Deformation under constant load has been studied as a function of prior loading rate and temperature. The constant-load displacement of the indenter into the sample shows classic relaxation kinetics and reveals the importance of anelasticity for the mechanical behavior of metallic glasses at the nanoscale

Fundamentals of interface phenomena in advanced bulk nanoscale materials

The review is devoted to a study of interface phenomena influencing advanced properties of nanoscale materials processed by means of severe plastic deformation, high-energy ball milling and their combinations. Interface phenomena include processes of interface defect structure relaxation from a highly nonequilibrium state to an equilibrium condition, grain boundary phase transformations and enhanced grain boundary and triple junction diffusivity. On the basis of an experimental investigation, a theoretical description of the key interfacial phenomena controlling the functional properties of advanced bulk nanoscale materials has been conducted. An interface defect structure investigation has been performed by TEM, high-resolution x-ray diffraction, atomic simulation and modeling. The problem of a transition from highly non-equilibrium state to an equilibrium one, which seems to be responsible for low thermostability of nanoscale materials, was studied. Also enhanced grain boundary diffusivity is addressed. Structure recovery and dislocation emission from grain boundaries in nanocrystalline materials have been investigated by analytical methods and modeling

Deep Learning for Action and Gesture Recognition in Image Sequences: A Survey

Interest in automatic action and gesture recognition has grown considerably in the last few years. This is due in part to the large number of application domains for this type of technology. As in many other computer vision areas, deep learning based methods have quickly become a reference methodology for obtaining state-of-the-art performance in both tasks. This chapter is a survey of current deep learning based methodologies for action and gesture recognition in sequences of images. The survey reviews both fundamental and cutting edge methodologies reported in the last few years. We introduce a taxonomy that summarizes important aspects of deep learning for approaching both tasks. Details of the proposed architectures, fusion strategies, main datasets, and competitions are reviewed. Also, we summarize and discuss the main works proposed so far with particular interest on how they treat the temporal dimension of data, their highlighting features, and opportunities and challenges for future research. To the best of our knowledge this is the first survey in the topic. We foresee this survey will become a reference in this ever dynamic field of research

Pectin methyl esterases and rhamnogalacturonan hydrolases: weapons for successful Monilinia laxa infection in stone fruit?

The secretion of cell wall‐degrading enzymes is one of the mechanisms used by necrotrophic fungi to colonize host tissues. However, information about virulence factors of Monilinia spp., the causal agents of brown rot in stone fruit, is scarce. Plant cell walls have three main components that are broken down by fungal enzymes: cellulose, hemicellulose and pectin. In order to identify Monilinia laxa candidate proteins involved in pectin hydrolysis, two in vitro approaches were conducted: (i) phenotypic and ecophysiological characterization of growth of the pathogen at different pHs, in glucose‐ and pectin‐containing solid media for 7 days' incubation; and (ii) expression analysis of genes encoding M. laxa pectin methyl esterases (MlPMEs) and rhamnogalacturonan hydrolases (MlRG‐HYDs) after incubation for 0.5, 2, 6, 24 and 48 h in glucose‐ and pectin‐containing liquid media. Phenotypic tests showed the role of carbon source on M. laxa growth rate and aggressiveness, and indicated that pectinases were greatly affected by pH. Gene expression analyses uncovered differences among members of each family of pectinases and between the two families, defining sets of genes expressed at earlier (0.5–6 h) and later (48 h) phases. Notably, the up‐ or down‐regulation of these target genes was carbon source‐dependent. Finally, an in vivo study confirmed the synergistic and complementary role that these genes play in the M. laxa–stone fruit pathosystem. Based on these results, it is hypothesized that MlPME2, MlRG‐HYD1 and MlRG‐HYD2 may be potential virulence factors of M. laxa in the process from infection to colonization.info:eu-repo/semantics/acceptedVersio