Spectral Fourier Method
Mostrando 1-12 de 41 artigos, teses e dissertações.
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1. Optimization of structures subjected to dynamic load: deterministic and probabilistic methods
Abstract This paper deals with the deterministic and probabilistic optimization of structures against bending when submitted to dynamic loads. The deterministic optimization problem considers the plate submitted to a time varying load while the probabilistic one takes into account a random loading defined by a power spectral density function. The correlation
REM, Int. Eng. J.. Publicado em: 2016-09
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2. Studies on Growth, Spectral, Thermal, Mechanical and Optical Properties of 4-Bromoanilinium 4-Methylbenzenesulfonate Crystal: A Third Order Nonlinear Optical Material
Abstract 4-Bromoanilinium 4-methylbenzenesulfonate (4BPTS) single crystal was successfully grown from ethanol by slow evaporation method at room temperature. The structure of grown crystal was confirmed by single crystal X-ray diffraction studies. The presence of functional groups of grown crystal was confirmed by the Fourier transform infrared spectroscopy
Mat. Res.. Publicado em: 18/07/2016
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3. Comparison of In-Flight Measured and Computed Aeroelastic Damping: Modal Identification Procedures and Modeling Approaches
ABSTRACT The Operational Modal Analysis technique is a methodology very often applied for the identification of dynamic systems when the input signal is unknown. The applied methodology is based on a technique to estimate the Frequency Response Functions and extract the modal parameters using only the structural dynamic response data, without assuming the kn
J. Aerosp. Technol. Manag.. Publicado em: 2016-06
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4. Green method by diffuse reflectance infrared spectroscopy and spectral region selection for the quantification of sulphamethoxazole and trimethoprim in pharmaceutical formulations
Um método alternativo para quantificação de sulfametoxazol (SMZ) e trimetoprima (TMP), empre gando espectrometria por refletância difusa no infra vermelho por transformada de Fourier (DRIFTS) e regressão por mínimos quadrados parciais (PLS) foi desenvolvido. Regressão por mínimos quadrados parciais por intervalo (iPLS) e por sinergismo de intervalos
An. Acad. Bras. Ciênc.. Publicado em: 04/03/2016
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5. Analysis of saliva by Fourier transform infrared spectroscopy for diagnosis of physiological stress in athletes
Introduction Saliva is the most promising biofluid to monitor the physiological state of athletes, because this method is not invasive and has low contamination risks. The characterization of saliva by Fourier transform infrared spectroscopy (FT-IR) has been studied as an alternative technique to the standard clinical analysis. However, methodological proce
Res. Biomed. Eng.. Publicado em: 2015-04
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6. Fourier transform infrared-attenuated total reflectance (FTIR-ATR) spectroscopy and chemometric techniques for the determination of adulteration in petrodiesel/biodiesel blends
We propose an analytical method based on fourier transform infrared-attenuated total reflectance (FTIR-ATR) spectroscopy to detect the adulteration of petrodiesel and petrodiesel/palm biodiesel blends with African crude palm oil. The infrared spectral fingerprints from the sample analysis were used to perform principal components analysis (PCA) and to constr
Quím. Nova. Publicado em: 2014-06
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7. Desenvolvimento de ferramenta de comparação de técnicas de processamento de sinais para determinar fadiga muscular por meio do sinal emg / Toolkit development for signals processing technics comparison to detect muscular fadigue by EMG signal
This study aimed to development of a computational tool for electromyographic signal (EMG) analysis by signal processing techniques to determine muscular fatigue. With Ethics Committee of Federal University of Goiás approve were recorded from the dominant biceps brachii of 10 volunteers, that did not ever had muscular disease. The protocol consisted on get
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 09/07/2012
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8. Planar multilayer structure analysis: an educational approach
This paper discusses how symbolic computation combined with a circuit model can be used for analyzing planar multilayer structures, in a manner suitable for educational approach. Working in the Fourier domain, expressions for the transversal spectral Green’s functions are evaluated in compact, closed form using the symbolic computation capability of the Ma
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2012-06
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9. Characterization of laser Doppler signal fluctuations in microvascular flow / Caracterização das flutuações do sinal laser doppller do fluxo microvascular
The laser Doppler flow signal from the skin (LDFS) has low-frequency fluctuations which are related to microvascular mechanisms of flow control. The Fourier and the wavelet spectral analysis has been used to correlate fluctuations in the LDFS with the metabolic, metabolic NO-dependent, neurogenic and myogenic mechanisms of control in the frequency intervals
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 19/08/2011
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10. Modelagem matemática de jatos em desenvolvimento espacial usando a metodologia pseudoespectral de Fourier
A busca por métodos de alta acurácia e alta taxa de convergência com a finalidade de resolver as equações de Navier-Stokes é de grande interesse para estudiosos de CFD. Essa busca é motivada, pois existem fenômenos físicos, como a turbulência nos fluidos, para os quais apenas metodologias que possuem uma alta acurácia permitem obter uma solução
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 12/08/2011
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11. Modelagem matemática de escoamentos bifásicos usando o Meto- Do Espectral de Fourier / Mathematics modeling of two-phase ows using spectral method of Fourier
A simulação numérica de escoamentos bifásicos requer alta acurácia para se obter maiores detalhes do escoamento. Além disso, busca-se baixo custo computacional, pois de modo geral, as metodologias necessitam de um elevado refinamento da malha ou possuem um grande estêncil de discretização, o que as torna onerosas. Portanto, o presente trabalho prop�
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 25/03/2011
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12. Numerical solution of Navier-Stokes equations using a hybrid methodology of immersed boundary and Fourier pseudo-spectral / Solução numérica das Equações de Navier-Stokes usando uma hibridação das metodologias Fronteira Imersa e Pseudo-Espectral de Fourier
No presente trabalho é desenvolvida uma nova metodologia para a solução das equações de Navier-Stokes na formulação incompressível aplicada a escoamentos sobre geometrias complexas. Ela é baseada no acoplamento da metodologia pseudo-espectral de Fourier (MPEF) juntamente com a metodologia da fronteira imersa (MFI). As principais particularidades do
Publicado em: 2011