938 resultados para corner cube retroreflector


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Pós-graduação em Matemática em Rede Nacional - IBILCE

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The study area is the Garoupa Field, located 75 km from the coast of Rio de Janeiro in bathymetric elevation of 125 m and it is the first important offshore discovery of the Campos Basin with hydrocarbon production in the Albian carbonates. The high significance of carbonate rock reservoirs for the global oil industry and its degree of complexity, combined with the fact that the Garoupa Field is a mature field, make this research project interesting to develop a re-exploratory vision of the study area. The objective of this paper is to characterize the physical properties of the Macae Group reservoirs in the Garoupa Field through well correlation techniques, petrophysical analysis and seismic interpretation (3D), in order to evaluate qualitatively and quantitatively the response of geophysical data to the presence of carbonate rock reservoirs. From the analysis of well profiles (gamma ray, resistivity, density and sonic) it was possible to identify six reservoir levels in the Quissamã Formation. As a result, the reservoirs have good correlation between the wells in the Garoupa Field and show lateral facies variation. In the seismic interpretation, structural contour maps were generated in time (ms) from the top of the Macae Group and two horizons that correspond to the reservoir levels. These maps show that the oil producing area of this field is a structural high located at the west of the interpreted seismic cube, and it was classified as a rollover limited by lateral faults forming a horst. The seismic attribute maps show a good response to the reservoirs of the Garoupa Field because they are associated with amplitude anomalies, verified by the correlation between the physical properties of the reservoir rock and seismic data through cross plots, with emphasis in a linear correlation between the resistivity profile and the values of Maximum Absolute Amplitude and RMS Amplitude attributes

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Pós-graduação em Matemática em Rede Nacional - IBILCE

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Construction techniques with ruler and the compasses, fundamental on Euclidean geometry, have been related to modern algebraic theories such as solving equations and extension of bodies from the works by Paolo Ruffini (1765-1822), Niels Henrik Abel (1802-1829) and Evariste Galois (1811-1832). This relation could provide an answer to some famous problems, from ancient Greece, such as doubling the cube, the trisection Angle, the Quadrature of the Circle and the construction of regular polygons, which remained unsolved for over two thousand years. Also important for our purposes are the notions of algebraic numbers, transcendental and the criteria for constructability, of those numbers. The objective of this study is to reconstruct relevant steps of geometric constructions with ruler (unmarked) and the compasses, from the elementary to the outcome buildings, in the nineteenth century, considering those mentioned problems.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The local anesthetic articaine (ATC) is widely used in dentistry; however, its side effects can include paresthesia and nerve injury. Polymeric nanocapsules (PN) can be used as carriers for drugs, and help to reduce undesirable symptoms. The objective of this study was to evaluate the influence of different factors on the average size, polydispersion, and encapsulation efficiency of PN containing ATC. Poly(ε-caprolactone) (PCL) nanocapsules containing ATC were prepared by the oil-in-water emulsion/solvent evaporation method. The final ATC concentration was 2%. The preparation conditions were optimized using a central composite blocked cube-star design to investigate the influence of two variables at five levels, with 22 factorial points (–1 and +1), two replicates of the central point, 2×2 axial points (–1.414 and +1.414), and an orthogonal distribution, resulting in 10 experiments. The factors varied were the PVA concentration and the sonication time. The nanocapsules showed a satisfactory size range, a polydispersivity index less than 0.2, and high encapsulation efficiency. The values of the factors had no significant influence on either average size or polydispersion, although the encapsulation efficiency was significantly influenced by the sonication time. Improved formulations were identified using the central composite design, which revealed that the main consideration in selecting a suitable formulation was the encapsulation efficiency. Two of the formulations showed both high encapsulation efficiency and colloidal characteristics appropriate for the route of administration.

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In the present work, we report the synthesis and characterization of NaNbO3 particles obtained by microwave-assisted hydrothermal method from Nb2O5 and NaOH. The synthesis was made at different periods at 180 °C and 300W. The crystallization of NaNbO3 structures produced Na2Nb2O6.H2O in the intermediate phase with fiber-like morphology, and this is associated with the synthesis time. Pure orthorhombic NaNbO3 with cube-like morphology originates after synthesizing for 240 minutes. To verify the remnant polarization of particles, films were obtained by electrophoresis process and sintered at 800°C for 10 minutes in a microwave furnace. The films characterization indicated that films of niobate with fiber-like morphology present remaining polarization, and the morphology of cubes did not show remaining polarization. Considering these results, it can be concluded that the morphology implemented ferroelectric property of NaNbO3.

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The city of Ilha Comprida, located on the Environmental Protection Area Cananéia-Iguape-Peruíbe (APA CIP) and Lagoon Estuary Complex of Iguape-Cananéia-Paranaguá, is located at the southern end of the coast of the state of São Paulo. Ilha Comprida is a progradational barrier consists predominantly of sandy sediments of the Quaternary Period. Bibliographic and cartographic surveys demonstrate a large amount of sediments in the last centuries, leading to the expansion of the island in hundreds of meters towards SW / NE. The island has been suffering intense morphological change in the northeast corner - NE, growing 35 meters per year. The objective of this study is to measure and analyze the floristic diversity found in its extreme NE, recent accumulation area of sediment, comparing the results with data obtained in equivalent segment, located on the edge SW, agradation preterit area. Given this reality, we chose to assess how the process of ecological succession respond to these dynamics. That is, if we think of ecological succession, NE end (latest) is assumed to possess plant species in the initial stage of succession as well as the SW portion. However, it is assumed certain differentiation between species in both areas, and less diversity in the first case (NE). Using the method of fixed installments adopted for similar quadrants, we attempted to measure and analyze the floristic diversity of the NE end and compare the data obtained in the field with those listed for the SW end. The results confirmed the hypothesis of the research, and prompted several questions that point to the need for further deepening research on this theme

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In this paper, a method is proposed to refine the LASER 3D roofs geometrically by using a high-resolution aerial image and Markov Random Field (MRF) models. In order to do so, a MRF description for grouping straight lines is developed, assuming that each projected side contour and ridge is topologically correct and that it is only necessary to improve its accuracy. Although the combination of laser data with data from image is most justified for refining roof contour, the structure of ridges can give greater robustness in the topological description of the roof structure. The MRF model is formulated based on relationships (length, proximity, and orientation) between the straight lines extracted from the image and projected polygon and also on retangularity and corner injunctions. The energy function associated with MRF is minimized by the genetic algorithm optimization method, resulting in the grouping of straight lines for each roof object. Finally, each grouping of straight lines is topologically reconstructed based on the topology of the corresponding LASER scanning polygon projected onto the image-space. The results obtained were satisfactory. This method was able to provide polygons roof refined buildings in which most of its contour sides and ridges were geometrically improved.

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Linear resonant harvesters have been the most common type of generators used to scavenge energy from mechanical vibrations. When subject to harmonic excitation, good performance is achieved once the device is tuned so that its natural frequency coincides with the excitation frequency. In such a situation, the average power harvested in a cycle is proportional to the cube of the excitation frequency and inversely proportional to the suspension damping, which is sought to be very low. However, a very low damping involves a relatively long transient in the system response, where the classical formulation adopted for steady-state regimes do not hold. This paper presents an investigation into the design of a linear resonant harvester to scavenge energy from time-limited harmonic excitations involving a transient response, which could be more likely in some practical situations. An application is presented considering train-induced vibrations.

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A novel optical setup for imaging through reflection holography with Bi12TiO20 (BTO) sillenite photorefractive crystals is proposed. Aiming a compact, robust and simple optical setup the lensless Denisiuk arrangement was chosen, using a He-Ne red laser as light source. In this setup the holographic medium is placed between the light source and the object. The beam impinging the crystal front face is the reference one, while the light scattered by the surface is the object beam in a holographic recording by diffusion. In order to allow the readout of the diffracted wave only and to keep the setup simplicity a polarizing beam splitter cube (PBS) was positioned at the BTO input. The reference beam is s-polarized (polarization direction perpendicular to the table top) and the crystal. 〈001〉-axis is rotated by an angle γ with respect to the input polarization in order to make the transmitted object beam and the diffracted beam to have orthogonal polarizations. While the transmitted wave is reflected by the PBS at a right angle, the diffracted wave carrying the holographic reconstruction of the object passes through the PBS, being collected by a positive lens in order to form the holographic image at a CCD camera. The holographic recording with the grating vector is parallel to the 〈100〉-axis. An expression for the diffracted wave intensity as a function of γ was derived, and this relation was experimentally investigated. © 2008 American Institute of Physics.