Mexican Institute of Petroleum

About: Mexican Institute of Petroleum is a government organization based out in Mexico City, Mexico. It is known for research contribution in the topics: Catalysis & Asphaltene. The organization has 3273 authors who have published 4170 publications receiving 87269 citations.

QVOA analysis: P-wave attenuation anisotropy for fracture characterization

Abstract: This paper investigates Q-anisotropy for characterizing fractured reservoirs — specifically, the variation of the seismic quality factor Q versus offset and azimuth QVOA .W e derive an analytical expression for P-wave attenuation in a transversely isotropic medium with horizontal symmetry axis HTI and provide a method QVOA for estimating fracture direction from azimuthally varying Q in PP-wave reflection data. The QVOA formula is similar to Ruger’s approximation for PP-wave reflection coefficients, the theoretical basis for amplitude variation with angle offset AVOA analysis. The technique for QVOA analysis is similar to azimuthal AVO analysis. We introduce two new seismic attributes: Q versus offset QVO gradient and intercept. QVO gradient inversion not only indicates fracture orientation but also characterizes Q-anisotropy. We relate the Q-anisotropy parameter Q to fractured-medium parameters and invert the QVO gradient to estimate Q. The attenuation parameter Q and Thomsen-style anisotropy parameter V are found to be interdependent. The attenuation anisotropy magnitude strongly depends on the host rock’s VS/VP parameter, whereas the dependence on fracture parameters is weak. This complicates the QVO gradient inversion for the fracture parameters. This result is independent of the attenuation mechanism. To illustrate the QVOA method in synthetic data, we use Hudson’s first-order effective-medium model of a dissipative fractured reservoir with fluid flow between aligned cracks and random pores as a possible mechanism for P-wave attenuation.

A model for coupling within-host and between-host dynamics in an infectious disease

Abstract: Studies on the modeling of the coupled dy- namics of infectious diseases at both the population level (the epidemic process or between-host dynamics) and at the cell level (the early viremia or within-host dynamics) are scarce. Most of them deal with these two processes separately by postulating assumptions that render them decoupled. In this work, we present a new model that allows the two dynamic processes to explicitly depend on each other. It is shown that new properties can emerge from the coupled system and more complex dynamics may be expected.

Nonlinear effects in the electrophoresis of a spherical colloidal particle

Abstract: The reduced electrophoretic mobility-reduced zeta potential relationship for a charged macroparticle is shown to be nonuniversal and to be highly nonlinear. In agreement with experimental results, a mobility reversal due to the macroion's charge inversion and a nonlinear dependence of the mobility on salt concentration is obtained.

Exact solutions to D-dimensional Schrödinger equation with a pseudoharmonic oscillator

Abstract: The exact solutions to the Schrodinger equation with a pseudoharmonic oscillator in an arbitrary dimensionD is presented.