Automatic neural generalized font identification

The final publication is available at Springer via http://dx.doi.org/10.1007/978-1-4471-1599-1_116Proceedings of the 8th International Conference on Artificial Neural Networks, Skövde, Sweden, 2–4 September 1998Neural methods are gaining a steady acceptance as powerful tools in a variety of pattern detection problems, OCR certainly being one of them. The concrete implementation of these neural OCR systems is of course a well guarded corporate secret, but in broad terms it can be said that in most of the cases, multilayer perceptrons (MLPs) are used. There are several reasons for the MLPs’ success. To begin with, they are based in well understood mathematical and statistical principles and there are efficient tools and methodologies for their training and evaluation. Furthermore they have good generalization properties.With partial support of grant TIC 95-965 of Spain's CICy

The formation of nanotubes and nanocoils of molybdenum disulphide

This work reports the successful realization of MoS2 nanotubes by a novel intercalation chemistry and hydrothermal treatment. An inorganic-organic precursor of hexadecylamine (HDA) and molybdenum disulphide (MoS2) were used in synthesizing the nanocomposite comprising laminar MoS2 with HDA intercalated in the interlaminar spacing. The formation of MoS2 nanotubes occurred during hydrothermal treatment (HT) by a self-organized rolling mechanism. The nanotubes were observed to have dimensions 2-12 µm in length and inner diameters typically in the range of 25-100 nm. We also report the formation of amorphous nanocoils of MoS2 obtained during similar procedures

Pressure induced anisotropy of electrical conductivity in polycrystalline molybdenum disulfide

Anisotropic specimens of MoS2 are obtained by pressing the microcrystalline powder into special die. This inelastic compression results in a rearrangement of the disulfide micro platelets observed by atomic force microscopy and reflected in the macroscopic anisotropy in electrical conductivity in these samples. The conductivity measured parallel and perpendicular to the direction of applied pressure exhibits an anisotropy factor of 10 at 1 GPa. This behaviour of the conductivity as a function of applied pressure is explained as the result of the simultaneous influence of a rearrangement of the micro platelets in the solid and the change of the inter-grain distances

Vanadate conformation variations in vanadium pentoxide nanostructures

We report the comparative structural-vibrational study of nanostructures of nanourchins, nanotubes, and nanorods of vanadium oxide. The tube walls comprise layers of vanadium oxide with the organic surfactant intercalated between atomic layers. Both Raman scattering and infrared spectroscopies showed that the structure of nanourchins, nanotubes, and nanorods of vanadium oxide nanocomposite are strongly dependent on the valency of the vanadium, its associated interactions with the organic surfactant template, and on the packing mechanism and arrangement of the surfactant between vanadate layers. Accurate assignment of the vibrational modes to the V-O coordinations has allowed their comparative classification and relation to atomic layer structure. Although all structures are formed from the same precursor, differences in vanadate conformations due to the hydrothermal treatment and surfactant type result in variable degrees of crystalline order in the final nanostructure. The nanotube-containing nanourchins contain vanadate layers in the nanotubes that are in a distorted γ- V5+ conformation, whereas the the nanorods, by comparison, show evidence for V5+ and V4+ species-containing ordered VOx lamina

Atomic layer structure of vanadium oxide nanotubes grown on nanourchin structures

We report the detailed characterization of high quality vanadium oxide (VOx) nanotubes (NTs) and highlight the zipping of adjacent vanadate layers in such NTs formed on remarkable nanourchin structures. These nanostructures consist of high-density spherical radial arrays of NTs. The results evidence vanadate NTs with unprecedented uniformity and evidences the first report of vanadate atomic layer zipping. The NTs are ∼2 μm in length with inner diameters of 20-30 nm. The tube walls comprise scrolled triplet-layers of vanadate intercalated with organic surfactant. Such high-volume structures might be useful as open-access electrolyte scaffolds for lithium insertion-based charge storage devices

Comparative structural-vibrational study of nano-urchin and nanorods of vanadium oxide

We present a comparative structural–vibrational study of nanostructured systems of V2O5: nano-urchin (VONURs) which are spherical structures composed of a radially oriented array of VOx nanotubes (VOx-NTs) with a volumetric density of ∼40 sr–1, and vanadium oxide nanorods (VOx-NRDs) with an average length of ∼100 nm. The Raman scattering spectrum of the nano-urchin exhibits a band at 1014 cm–1 related to the distorted gamma conformation of the vanadium pentoxide (γ-V5+). The infrared vibrational spectra of the nanorods sample also exhibit a distorted laminar V2O5 structure with evidence observed for quadravalent V4+ species at 921 cm–1

Low-dimensional, hinged bar-code metal oxide layers and free-standing, ordered organic nanostructures from turbostratic vanadium oxide

Both low-dimensional bar-coded metal oxide layers, which exhibit molecular hinging, and free-standing organic nanostructures can be obtained from unique nanofibers of vanadium oxide (VOx). The nanofibers are successfully synthesized by a simple chemical route using an ethanolic solution of vanadium pentoxide xerogel and dodecanethiol resulting in a double bilayered laminar turbostratic structure. The formation of vanadium oxide nanofibers is observed after hydrothermal treatment of the thiol-intercalated xerogel, resulting in typical lengths in the range 2–6 µm and widths of about 50–500 nm. We observe concomitant hinging of the flexible nanofiber lamina at periodic hinge points in the final product on both the nanoscale and molecular level. Bar-coded nanofibers comprise alternating segments of organic–inorganic (thiols–VOx) material and are amenable to segmented, localized metal nanoparticle docking. Under certain conditions free-standing bilayered organic nanostructures are realized

Functionalization of lamellar molybdenum disulphide nanocomposite with gold nanoparticles

This work explores the functionalization of an organic-inorganic MoS2 lamellar compound, prepared by a Chemical Liquid Deposition Method (CLD), that has an interlamellar distance of ~5.2 nm, using clusters of gold nanoparticles. The gold nanoparticles have a mean diameter of 1.2 nm, a stability of ~85 days, and a zeta potential measured to be ζ = -6.8 mV (solid). The nanoparticles are localized in the hydrophilic zones, defined by the presence of amine groups of the surfactant between the lamella of MoS2. SEM, TEM, EDAX and electron diffraction provide conclusive evidence of the interlamellar insertion of the gold nanoparticles in the MoS2

Pensamientos de Santa Teresa de Jesús : extractados de sus obras para servir de meditación en cada dia del año

Copia digital : Junta de Castilla y León. Consejería de Cultura y Turismo, 201

DIVERSIDAD DE AVES DE SOTOBOSQUE EN BOSQUES TROPICALES, ÁREAS DE REGENERACIÓN NATURAL Y CULTIVOS DE PALMA AFRICANA EN HUMEDALES DEL LAGO DE IZABAL, GUATEMALA

Diversity of understory birds in tropical forests, natural recovery areas, and African oil palm crops in wetlands of the Izabal Lake, Guatemala. – African oil palm (Elaeis guineensis) crops have been identified as one of the most important threats to biodiversity of tropical forests. By mean of mist nets, species richness, diversity and structure of understory bird communities were studied in three vegetation types of a Neotropical wetland: humid tropical forest remnants, natural regeneration sites (“guamiles”), and African oil palm plantations. We captured a total of 734 birds of 106 species, belonging to 22 families. The habitat with highest diversity was forest (63 species and 329 individuals), followed by guamiles (62 species and 368 individuals) and finally oil palm plantations (11 species and 37 individuals). As expected, statistical differences were found among the studied habitats. Only 11% of species and 5% of the total captured birds were recorded in the African oil palm plantations. Our data show that oil palm cultivation represents a serious threat to biological diversity, making it a priority to generate guidelines based on scientific and conservation criteria