Produção Científica



Apresentação
07/11/2019

Microporosity Aspect Ratio of Carbonate Rocks Under Pressure
Carbonate rocks usually present a complex porous system, especially regarding the differences in pore geometry. When those rocks are submitted to external pressure variation, that variations in pore geometry may affect the elastic velocities. In this work, we studied the behavior of compressional and shear wave velocities in a set of carbonate rocks at different pressure stages. Our approach is based in a supposition of a dual porosity scenario and consisted in determining the mean value of the aspect ratio of the macro-meso pores through the analysis of optical microscopy images and use the Differential Effective Medium (DEM) theory to estimate the microporosity aspect ratio. The results showed that such microporosity aspect ratio decreases exponentially as pressure increases.
Apresentação
07/11/2019

Use of Bayesian Inference for Estimative of P-wave Arrival
The measurement of acoustic wave forms is present in exploration seismic, well logging and laboratory experiments. For instance, a commonly performed experiment for velocity measurements in cores is the first break picking. The measured data probably contain noise, either inherent to the measuring equipment or other factors. Develop new techniques to do this task automatically and more accurate is even more necessary over time.
Artigo em Revista
07/11/2019

Up/down acoustic wavefield decomposition using a single propagation and its application in reverse time migration
The separation of up- and downgoing wavefields is an important technique in the processing of multicomponent recorded data, propagating wavefields, and reverse time migration (RTM). Most of the previous methods for separating up/down propagating wavefields can be grouped according to their implementation strategy: a requirement to save time steps to perform Fourier transform over time or construction of the analytical wavefield through a solution of the wave equation twice (one for the source and another for the Hilbert-transformed source), in which both strategies have a high computational cost. For computing the analytical wavefield, we are proposing an alternative method based on the first-order partial equation in time and by just solving the wave equation once. Our strategy improves the computation of wavefield separation, and it can bring the causal imaging condition into practice. For time extrapolation, we are using the rapid expansion method to compute the wavefield and its first-order time derivative and then we can compute the analytical wavefield. By computing the analytical wavefield, we can, therefore, separate the wavefield into up- and downgoing components for each time step in an explicit way. Applications to synthetic models indicate that our method allows performing the wavefield decomposition similarly to the conventional method, as well as a potential application for the 3D case. For RTM applications, we can now use the causal imaging condition for several synthetic examples. Acoustic RTM up/down decomposition demonstrates that it can successfully remove the low-frequency noise, which is common in the typical crosscorrelation imaging condition, and it is usually removed by applying a Laplacian filter. Moreover, our method is efficient in terms of computational time when compared to RTM using an analytical wavefield computed by two propagations, and it is a little more costly than conventional RTM using the crosscorrelation imaging condition.
Tese de Doutorado
06/11/2019

Gustavo da Silva Costa. An√°lise de estabilidade e governabilidade em ve√≠culo submarino aut√īnomo utilizando OpenFOAM
Gustavo da Silva Costa. An√°lise de estabilidade e governabilidade em ve√≠culo submarino aut√īnomo utilizando OpenFOAM. 2019. SENAI/CIMATEC. Orientador: Ivan Costa da Cunha Lima.
Tese de Doutorado
06/11/2019

Florêncio Mendes Oliveira Filho. Modelagem com sinais de EEG: um nestudo com o coeficiente de correlação cruzada rho-DCCA
Florêncio Mendes Oliveira Filho. Modelagem com sinais de EEG: um nestudo com o coeficiente de correlação cruzada rho-DCCA. 2019. SENAI/CIMATEC. Orientador: Ivan Costa da Cunha Lima.
Tese de Doutorado
06/11/2019

Everaldo Freitas Guedes. Um modelo computacional para o monitoramento em tempo real da eficiênciae da interdependência do contágio entre mercados financeiros.
Everaldo Freitas Guedes. Um modelo computacional para o monitoramento em tempo real da eficiência e da interdependência do contágio entre mercados financeiros. 2019. SENAI/CIMATEC. Orientador: Ivan Costa da Cunha Lima.
Tese de Doutorado
06/11/2019

F√°bio Rodrigues Santos. An√°lise espectral de padr√Ķes de turbul√™ncia e vorticidade em dutos gerados por simula√ß√£o num√©ica utilizando OpenFOAM
F√°bio Rodrigues Santos. An√°lise espectral de padr√Ķes de turbul√™ncia e vorticidade em dutos gerados por simula√ß√£o num√©ica utilizando OpenFOAM. 2019. SENAI/CIMATEC. Oreintador: Ivan Costa da Cunha Lima.
Dissertação de Mestrado
06/11/2019

Alberto Ruiz Vieira de Melo Filho. Estudo de processo de injeção automotiva usando técnicas de simulação com OpenFOAM
Alberto Ruiz Vieira de Melo Filho. Estudo de processo de injeção automotiva usando técnicas de simulação com OpenFOAM. 2018. SENAI/CIMATEC. Orientador: Ivan Costa da Cunha Lima.
Dissertação de Mestrado
06/11/2019

Daniele Pantoja Monteiro. Inversão gravimétrica 2D eficiente e estável do relevo do embasamento descontínuo
Daniele Pantoja Monteiro. Inversão gravimétrica 2D eficiente e estável do relevo do embasamento descontínuo. 2019. Universidade Federal do Pará. Orientador: Darcicléa Ferreira Santos.
Dissertação de Mestrado
06/11/2019

Jozinei Ferreira Lopes. Validade das aproxima√ß√Ķes 2D e 2,5D na interpreta√ß√£o magn√©tica usando prismas verticais justapostos.
Jozinei Ferreira Lopes. Validade das aproxima√ß√Ķes 2D e 2,5D na interpreta√ß√£o magn√©tica usando prismas verticais justapostos. Universidade Federal da Bahia. Orientador: Darcicl√©a Ferreira Santos.
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