Sub Band
Mostrando 13-24 de 50 artigos, teses e dissertações.
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13. Dependência das propriedades da região-D ionosférica com o ciclo de atividade solar / Dependence of ionospheric D region properties on solar activity cycle
The goal of this work is to provide new clues for a better understanding of the quiescent ionosphere during different solar activity conditions. For that we study the lower ionospheric response to external perturbations, as solar X-rays emitted during flares. We use solar X-ray fluxes provided by GOES satellites, and ionospheric SPA (Sudden Phase Anomalies)
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 06/07/2006
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14. Karyological characterization of four Neotropical fish species of the genus Hisonotus (Teleostei, Loricariidae, Hypoptopomatinae) from distinct Brazilian river basins
The karyotypes of four Hisonotus species (two provisionally-named species A and D, H. nigricauda, and H. leucofrenatus) were found to have the same diploid number of 2n = 54 and interstitial silver-staining nucleolus organizer regions (Ag-NORs) located on the long arm of the largest metacentric pair. The C-banding pattern appeared to be species-specific, wit
Genetics and Molecular Biology. Publicado em: 2006
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15. Composição e atividade antifúngica do óleo essencial de hortelã-pimenta (Mentha piperita L.) / Composition and antifungal activity of pepper mint (Mentha piperita L.) essential oil
Pepper mint (Mentha piperita L.) essential oil (EO), obtained by hydro distillation of dry leaves, was evaluated in vitro through a poison food assay (0.1; 0.2 and 0.3%) presented antifungal activity against Aspergillus flavus, A. ochraceous, A. niger, A. glaucus, Fusarium oxysporum, F. semitectum, Colletotrichum musae and C. gloeosporioides. The EO was frac
Publicado em: 2006
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16. ProduÃÃo de heterojunÃÃes de polianilina/silÃcio e nanofibras de polianilina para aplicaÃÃes em dispositivos hÃbridos
In this work we develop the methodology for the synthesis and fabrication of Polyaniline (PANI) â Silicon (Si) heterojunctions, with great potential for technological applications as sensors in different areas such as optics, ionizing radiation and gas detection. Besides, we were able to implement the electrospinnin technique with the goal of producing poly
Publicado em: 2006
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17. Neodymium in hydrogenated amorphous silicon sub-nitrides (a-SiNx:H) / Neodimio em sub-nitretos de silicio amorfo hidrogenado (a-SiNx:H)
In this work, we report a study of the photoluminescence (PL) optimization of a-SiNx:H
thin films prepared by RF co-sputtering. The PL was investigated as a function of nitrogen and neodymium concentrations. We observed that the Nd ions are excited through the amorphous matrix. The excitation mechanism is more efficient in samples where the optical gap E0 Publicado em: 2005
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18. Dois olhares na assistencia humanizada ao parto : vivencia de mulheres e opinião de profissionais de saude
This project was composed by two descriptive studies of the routines proposed for the humanization of care during childbirth recommended by the Ministry of Health, and implemented at an university maternity starting in 2001. The goal was to evaluate opinions and perceptions of women and professionals on these new routines, contrasting their views. At the fir
Publicado em: 2005
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19. Transporte quântico em poços parabólicos largos / Transportation wide parabolic quantum wells
The gradual progress, or evolution, of the two-dimensional (2D) toward three-dimensional (3D) Landau states was studied in wide parabolic quantum Wells (W = 1000 6000 Å). As transport technique, we used measurements of the magnetoresistence in intense (B = 0 15 T) and tilted ( = 0 90°; perpendicular parallel) magnetic Field at low temperature (T = 50 Mk).
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 25/07/2003
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20. Um metodo de compressão de audio baseado na codificação de Subbandas Wavelets
This work presents a method for audio compression based on wavelets sub-band quantization and coding, and proposes a coder based on that method. First, the work describes the Wavelet Transform with emphasis on the concepts of multi-resolution analyzes and their relationship with filtering processes and decomposition in sub-bands. A description of the Wavelet
Publicado em: 2001
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21. A norma padrão de incidência do imposto sobre a transmissão do direito de propriedade de bens imóveis- inter vivos
The presente research aims at describing the criteria fonning the basic rule of tributary, incidence of the Imposto sobre a Transmissão do Direito de Propriedade de Bens Imóveis - inter vivos (Transference of Right of Property of Real Estate Tax - inter vivos), by comparing the ordinary legislation which established such a taxation with the principIes info
Publicado em: 2001
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22. MATHEMATICAL AND EXPERIMENTAL APPROACHES IN SHAPE-ADAPTATIVE VIDEO CODING / ABORDAGENS MATEMÁTICAS E EXPERIMENTAIS EM CODIFICAÇÃO DE VÍDEO ADAPTATIVA À FORMA
This thesis investigates shape adaptative coding of arbitrarily shaped segments. The texture and contour coding efficiency is discussed and solutions to tackle the associated problems are proposed. The presented methods are evaluated using standard image sequences. A mathematical approach for shape-adaptative transforms using linear operators is developed, f
Publicado em: 2000
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23. ESTIMAÇÃO EM TEMPO REAL DE SENÓIDES HARMÔNICAS POR DECOMPOSIÇÃO EM SUB-BANDAS / REAL TIME HARMONIC SINE WAVE ESTIMATION BY SUB-BAND DECOMPOSITION
A medição da qualidade de energia é um aspecto cada vez mais importante com o avanço tecnológico. Um destes aspectos é a estimação dos harmônicos em sinais de potência. Este trabalho, apresenta um algoritmo para obter, simultaneamente, os valores reais de freqüência, amplitude e fase de cada componente do sinal, baseados em valores distorcidos or
Publicado em: 1999
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24. IMAGE COMPRESSION USING WAVELET TRANSFORM AND TRELLIS CODE VECTOR QUANTIZATION WITH ENTROPY CONSTRAINT / COMPRESSÃO DE IMAGENS USANDO TRANSFORMADA WAVELET E QUANTIZAÇÃO VETORIAL CODIFICADA EM TRELIÇA COM RESTRIÇÃO DE ENTROPIA
This dissertation presentes a low bit rate image coder using a 10 sub-band image decomposition base don the wavelet transform. Some blocks of coefficients of the high frequency sub-bands are discarded by a technique of irrelevancy reduction. The remaning blocks are classified into edges and non-edges, and coded by ECTCVQ (Entropy- constrained Trellis Vector
Publicado em: 1998