Promoção de eventos culturais na Biblioteca da Embrapa Florestas: responsabilidade social e cultural.

Apresenta uma reflexão sobre a responsabilidade e compromisso social das bibliotecas e descreve ações desenvolvidas por uma biblioteca especializada na área de pesquisa com o objetivo de promover a biblioteca, incentivar atividades culturais, bem como de sociabilizar a mesma na empresa

Potencialidades do guandu como adubação verde em áreas cultivadas com cana-de-açúcar nos tabuleiros costeiros de Alagoas.

Grande parte da produção de cana-de-açúcar em Alagoas está concentrada nos tabuleiros costeiros, região litorânea com precipitação favorável ao desenvolvimento da cultura. Contudo, os solos de tabuleiros apresentam algumas limitações agrícolas referentes à baixa resistência mecânica a operações de preparo de solo, baixa fertilidade natural e de retenção de água e nutrientes. Os solos são caracterizados ainda por apresentarem uma alta coesão natural dos horizontes, o que dificulta a penetração e desenvolvimento radicular das plantas, a disponibilidade de água, a aeração e a absorção de nutrientes, podendo influenciar negativamente no desenvolvimento das culturas.bitstream/item/123063/1/Potencialidades-do-guandu.pd

When Should the Chicken Cross the Road? - Game Theory for Autonomous Vehicle - Human Interactions

Autonomous vehicle localization, mapping and planning in un-reactive environments are well-understood, but the human factors of complex interactions with other road users are not yet developed. This study presents an initial model for negotiation between an autonomous vehicle and another vehicle at an unsigned intersections or (equivalently) with a pedestrian at an unsigned road-crossing (jaywalking), using discrete sequential game theory. The model is intended as a basic framework for more realistic and data-driven future extensions. The model shows that when only vehicle position is used to signal intent, the optimal behaviors for both agents must include a non-zero probability of allowing a collision to occur. This suggests extensions to reduce this probability in future, such as other forms of signaling and control. Unlike most Game Theory applications in Economics, active vehicle control requires real-time selection from multiple equilibria with no history, and we present and argue for a novel solution concept, meta-strategy convergence, suited to this task

An integrated software system for geometric correction of LANDSAT MSS imagery

A system for geometrically correcting LANDSAT MSS imagery includes all phases of processing, from receiving a raw computer compatible tape (CCT) to the generation of a corrected CCT (or UTM mosaic). The system comprises modules for: (1) control of the processing flow; (2) calculation of satellite ephemeris and attitude parameters, (3) generation of uncorrected files from raw CCT data; (4) creation, management and maintenance of a ground control point library; (5) determination of the image correction equations, using attitude and ephemeris parameters and existing ground control points; (6) generation of corrected LANDSAT file, using the equations determined beforehand; (7) union of LANDSAT scenes to produce and UTM mosaic; and (8) generation of output tape, in super-structure format

Intersecting D-Branes on Shift Z2 x Z2 Orientifolds

We investigate Z2 x Z2 orientifolds with group actions involving shifts. A complete classification of possible geometries is presented where also previous work by other authors is included in a unified framework from an intersecting D-brane perspective. In particular, we show that the additional shifts not only determine the topology of the orbifold but also independently the presence of orientifold planes. In the second part, we work out in detail a basis of homological three cycles on shift Z2 x Z2 orientifolds and construct all possible fractional D-branes including rigid ones. A Pati-Salam type model with no open-string moduli in the visible sector is presented.Comment: 36 pages, 4 figures, refs. adde

Control of the Light Interaction in a Semiconductor Nanoparticle Dimer Through Scattering Directionality

11 págs.; 4 figs.; 1 tab.Dimers of nanoparticles are very interesting for several devices due to the possibility of obtaining intense light concentrations in the gap between them. A dynamic control of this interaction to obtain either the maximum or minimum light through interferential effects could be also relevant for a multitude of devices such as chemical sensors or all-optical devices for interchip/intrachip communications. Semiconductor nanoparticles satisfying Kerker conditions present an anisotropic scattering distribution with a minimum in either the forward or the backward direction and prominent scattering in the contrary direction. The reduction or enhancement of the electromagnetic field in a certain direction can minimize or maximize the interaction with neighboring nanoparticles. In this paper, we consider a dimer of nanoparticles such that each component satisfies each one of the Kerker conditions. Depending on the arrangement of the nanoparticles with respect to the impinging light direction, we can produce a minimum or a maximum of the electric field between them, reducing or maximizing the interferential effects. The strong dependence of the directional conditions with external conditions, such as the incident wavelength, can be used to dynamically control the light concentration in the gap. Ó 2016 IEEEThis work was supported in part by the Ministerio de Economía y Competitividad of Spain under Grant TEC2013—50138—EXP and Grant TEC2013-47342-C2-2-R, by the RD Program of the Comunidad de Madrid under Grant SINFOTON S2013/MIT—2790, and by COST Action IC1208.Peer Reviewe

Graphene formed on SiC under various environments: Comparison of Si-face and C-face

The morphology of graphene on SiC {0001} surfaces formed in various environments including ultra-high vacuum, 1 atm of argon, and 10^-6 to 10^-4 Torr of disilane is studied by atomic force microscopy, low-energy electron microscopy, and Raman spectroscopy. The graphene is formed by heating the surface to 1100 - 1600 C, which causes preferential sublimation of the Si atoms. The argon atmosphere or the background of disilane decreases the sublimation rate so that a higher graphitization temperature is required, thus improving the morphology of the films. For the (0001) surface, large areas of monolayer-thick graphene are formed in this way, with the size of these areas depending on the miscut of the sample. Results on the (000-1) surface are more complex. This surface graphitizes at a lower temperature than for the (0001) surface and consequently the growth is more three-dimensional. In an atmosphere of argon the morphology becomes even worse, with the surface displaying markedly inhomogeneous nucleation, an effect attributed to unintentional oxidation of the surface during graphitization. Use of a disilane environment for the (000-1) surface is found to produce improved morphology, with relatively large areas of monolayer-thick graphene.Comment: 22 pages, 11 figures, Proceedings of STEG-2 Conference; eliminated Figs. 4 and 7 from version 1, for brevity, and added Refs. 18, 29, 30, 31 together with associated discussio

Individual differences in true and false memory retrieval are related to white matter brain microstructure

We sometimes vividly remember things that did not happen, a phenomenon with general relevance not only in the court-room. It is unclear, to what extent individual differences in false memories are driven by anatomical differences in memory relevant brain regions. Here we show in humans that microstructural properties of different white matter tracts as quantified using Diffusion Tensor Imaging (DTI) are strongly correlated with true and false memory recollection. To investigate these hypotheses we tested a large group of participants in a version of the Deese-Roediger-McDermott (DRM) paradigm (recall and recognition) and subsequently obtained DTI images. A voxel-based whole-brain level linear regression analysis was performed to relate fractional anisotropy to indices of true and false memory recall and recognition. True memory was correlated to diffusion anisotropy in the inferior longitudinal fascicle, the major connective pathway of the medial temporal lobe, whereas a greater proneness to retrieve false items was related to the superior longitudinal fascicle connecting fronto-parietal structures. Our results show that individual differences in white-matter micro-structure underlie true and false memory performance

Non-Abelian discrete gauge symmetries in 4d string models

We study the realization of non-Abelian discrete gauge symmetries in 4d field theory and string theory compactifications. The underlying structure generalizes the Abelian case, and follows from the interplay between gaugings of non-Abelian isometries of the scalar manifold and field identifications making axion-like fields periodic. We present several classes of string constructions realizing non-Abelian discrete gauge symmetries. In particular, compactifications with torsion homology classes, where non-Abelianity arises microscopically from the Hanany-Witten effect, or compactifications with non-Abelian discrete isometry groups, like twisted tori. We finally focus on the more interesting case of magnetized branes in toroidal compactifications and quotients thereof (and their heterotic and intersecting duals), in which the non-Abelian discrete gauge symmetries imply powerful selection rules for Yukawa couplings of charged matter fields. In particular, in MSSM-like models they correspond to discrete flavour symmetries constraining the quark and lepton mass matrices, as we show in specific examples.Comment: 58 pages; minor typos corrected and references adde

Towards a Realistic Type IIA T^6/Z_4 Orientifold Model with Background Fluxes, Part 1: Moduli Stabilization

We apply the methods of DeWolfe et al. [hep-th/0505160] to a T^6/Z_4 orientifold model. This is the first step in an attempt to build a phenomenologically interesting meta-stable de Sitter model with small cosmological constant and standard model gauge groups.Comment: 1+30 pages, 2 figures, LaTeX, v2: minor corrections, stability analysis of b_a moduli added, refs added, version accepted for publication in JHE