LIACIR LUCENA - Academia.edu (original) (raw)
Papers by LIACIR LUCENA
We find that 2-dimensional (2-D) critical branched polymers with no impurities conclusively belon... more We find that 2-dimensional (2-D) critical branched polymers with no impurities conclusively belong to the same universality class as 2-D random percolation clusters, although pure critical 3-D branched polymers do not belong to the 3-D percolation universality class. We find, moreover, that the fractal dimension of critical branched polymers in 2-D is independent of the presence of a random environment, and explore possible explanations for these strange results. We also report that when there are no impurities the critical branching probability in 3-D is bc=3.34e-4 +- 0.16e-4.
Integrated Computer-Aided Engineering, 2005
ABSTRACT
Physica A: Statistical Mechanics and its Applications, 2000
A method for obtaining critical properties is presented. Based on self-organized criticality, it ... more A method for obtaining critical properties is presented. Based on self-organized criticality, it drives the system spontaneously to the critical point, providing an e cient way to estimate critical properties. The method is illustrated for Ising spin systems, and despite the small lattice sizes used, it yields critical temperatures and ÿ exponents in good agreement with those available in the literature.
Physics Letters A, 2008
... In fact, they have been applied in several situation such as turbulence [1], [2] and [10], di... more ... In fact, they have been applied in several situation such as turbulence [1], [2] and [10], diffusion on fractals [11], transport of fluid in porous media [12], relaxation to equilibrium in systems (eg, polymers chains and membranes) with long temporal memory [13], [14], [15] and [16 ...
Physical Review Letters, 1994
Physica A: Statistical Mechanics and its Applications, 1999
We present a Monte Carlo study of a linear chain (d = 1) with long-range bonds whose occupancy pr... more We present a Monte Carlo study of a linear chain (d = 1) with long-range bonds whose occupancy probabilities are given by pij = p=r ij (06p61; ¿0) where rij = 1; 2; : : : is the distance between sites. The → ∞ (= 0) corresponds to the ÿrst-neighbor ("mean ÿeld") particular case. We exhibit that the order parameter P∞ equals unity ∀p ¿ 0 for 06 61, presents a familiar behavior (i.e., 0 for p6pc() and ÿnite otherwise) for 1 ¡ ¡ 2, and vanishes ∀p ¡ 1 for ¿ 2. Our results conÿrm recent conjecture, namely that the nonextensive region (06 61) can be meaningfully unfolded, as well as uniÿed with the extensive region (¿ 1), by exhibiting P∞ as a function of p * where (1 − p *) = (1 − p) N * (N * ≡ (N 1− =d − 1)=(1 − =d); N being the number of sites of the chain). A corollary of this conjecture, now numerically veriÿed, is that pc˙(− 1) in the → 1 + 0 limit.
Physica A: Statistical Mechanics and its Applications, 2001
Polyelectrolytes are of great importance in different branches of chemistry and biology. DNA is a... more Polyelectrolytes are of great importance in different branches of chemistry and biology. DNA is a very good example of a polyelectrolyte of biological relevance. In this paper, we describe DNA solutions in the presence of multivalent salts and amphiphiles. After ...
Physica A: Statistical Mechanics and its Applications, 2005
The multifractal lattice Q mf is an object defined on a square using a section parameter z. Q mf ... more The multifractal lattice Q mf is an object defined on a square using a section parameter z. Q mf has been used to study percolation in heterogeneous multifractal structures. In this work we use a group theory approach to explore mathematical properties of Q mf. The self-affine object Q mf is described by the combination of distinct discrete groups: the finite groups of rotation and inversion and the infinite groups of translation and dilation. We address the cell elements of the lattice Q mf using a Cayley tree. We determine the Cartesian coordinates of each cell using group properties in a recursive equation. The rich group structure of Q mf allows an infinite number of distinct tilling for a single z.
Physica A: Statistical Mechanics and its Applications, 2004
In this work we investigate the distribution of shortest paths in percolation systems at the perc... more In this work we investigate the distribution of shortest paths in percolation systems at the percolation threshhold in two dimensions (2D). We study paths from one given point to multiple other points. In oil recovery terminology, the given single point can be mapped to an injection well (injector) and the multiple other points to production wells (producers). In the previously studied standard case of one injection well and one production well separated by Euclidean distance r, the distribution of shortest paths l, P(l|r), shows a power-law behavior with exponent g l =2:14 in 2D. Here we analyze the situation of one injector and an array A of producers. Symmetric arrays of producers lead to one peak in the distribution P(l|A), the probability that the shortest path between the injector and any of the producers is l, while the asymmetric conÿgurations lead to several peaks in the distribution. We analyze conÿgurations in which the injector is outside and inside the set of producers. The peak in P(l|A) for the
Proceedings of the 16th International Congress of the Brazilian Geophysical Society&Expogef
Contents of this paper were reviewed by the Technical Committee of the 16 th International Congre... more Contents of this paper were reviewed by the Technical Committee of the 16 th International Congress of the Brazilian Geophysical Society and do not necessarily represent any position of the SBGf, its officers or members. Electronic reproduction or storage of any part of this paper for commercial purposes without the written consent of the Brazilian Geophysical Society is prohibited.
arXiv: Soft Condensed Matter, 2003
We study a simple model of DNA divalent cationic surfactant complexation. We find that the combin... more We study a simple model of DNA divalent cationic surfactant complexation. We find that the combination of electrostatic and hydrophobic effects leads to a cooperative phenomenon in which as the amphiphile is added to the solution containing DNA, a large fraction of the DNA's charge is neutralized by the condensed divalent cationic surfactants, forming the surfoplex. This binding transition occurs for concentrations that are lower for divalent than for monovalent surfactants. Since the electrostatic strength is larger in the first case and the amount of surfactant lower, we suggest that multivalent amphiphilic molecules would be more efficient than monovalent for transfection.
Proceedings of the 16th International Congress of the Brazilian Geophysical Society&Expogef, 2019
Contents of this paper were reviewed by the Technical Committee of the 16 th International Congre... more Contents of this paper were reviewed by the Technical Committee of the 16 th International Congress of the Brazilian Geophysical Society and do not necessarily represent any position of the SBGf, its officers or members. Electronic reproduction or storage of any part of this paper for commercial purposes without the written consent of the Brazilian Geophysical Society is prohibited.
Journal of Geophysics and Engineering
To eliminate the dependency on a good initial model of the traditional full waveform inversion (F... more To eliminate the dependency on a good initial model of the traditional full waveform inversion (FWI) method, we propose an optimisation method combining a derivative free optimisation method of modified particle swarm with gradient descent search. We worked with the acoustic wave approximation, in two dimensions, with the synthetic Marmousi velocity model as the test case. We were able to obtain a high-precision inversion of this model, comparable to traditional FWI methods, with the distinct advantage of not using an initial model close to the global optimal, as would usually be required. For this result, we used a progressive inversion scheme by consecutive layers, and a modified particle swarm optimisation algorithm where we introduced the gradient of the misfit function as a local search guide, and other regularization terms.
Proceedings of the 16th International Congress of the Brazilian Geophysical Society&Expogef
Contents of this paper were reviewed by the Technical Committee of the 16 th International Congre... more Contents of this paper were reviewed by the Technical Committee of the 16 th International Congress of the Brazilian Geophysical Society and do not necessarily represent any position of the SBGf, its officers or members. Electronic reproduction or storage of any part of this paper for commercial purposes without the written consent of the Brazilian Geophysical Society is prohibited.
Proceedings of the 16th International Congress of the Brazilian Geophysical Society&Expogef
Contents of this paper were reviewed by the Technical Committee of the 16 th International Congre... more Contents of this paper were reviewed by the Technical Committee of the 16 th International Congress of the Brazilian Geophysical Society and do not necessarily represent any position of the SBGf, its officers or members. Electronic reproduction or storage of any part of this paper for commercial purposes without the written consent of the Brazilian Geophysical Society is prohibited.
SEG Technical Program Expanded Abstracts 2019
Physica A: Statistical Mechanics and its Applications
Using the small-world approach we suggest a network model for the economy. Our basic assumption i... more Using the small-world approach we suggest a network model for the economy. Our basic assumption is that the economic agents prefer to make business with the big business. This assumption makes the preferential attachment the main mechanism for the evolution of the economic network. We hypothesize that the connectivity of the economic network should reflect the wealth distribution of the
Nonlinear Processes in Geophysics
We employ the detrended fluctuation analysis (DFA) technique to investigate spatial properties of... more We employ the detrended fluctuation analysis (DFA) technique to investigate spatial properties of an oil reservoir. This reservoir is situated at Bacia de Namorados, RJ, Brazil. The data correspond to well logs of the following geophysical quantities: sonic, gamma ray, density, porosity and electrical resistivity, measured in 56 wells. We tested the hypothesis of constructing spatial models using data from fluctuation analysis over well logs. To verify this hypothesis, we compare the matrix of distances of well logs with the differences in DFA exponents of geophysical quantities using a spatial correlation function and the Mantel test. Our data analysis suggests that the sonic profile is a good candidate for representing spatial structures. Then, we apply the clustering analysis technique to the sonic profile to identify these spatial patterns. In addition, we use the Mantel test to search for correlations between DFA exponents of geophysical quantities.
Physica A: Statistical Mechanics and its Applications
ABSTRACT
We find that 2-dimensional (2-D) critical branched polymers with no impurities conclusively belon... more We find that 2-dimensional (2-D) critical branched polymers with no impurities conclusively belong to the same universality class as 2-D random percolation clusters, although pure critical 3-D branched polymers do not belong to the 3-D percolation universality class. We find, moreover, that the fractal dimension of critical branched polymers in 2-D is independent of the presence of a random environment, and explore possible explanations for these strange results. We also report that when there are no impurities the critical branching probability in 3-D is bc=3.34e-4 +- 0.16e-4.
Integrated Computer-Aided Engineering, 2005
ABSTRACT
Physica A: Statistical Mechanics and its Applications, 2000
A method for obtaining critical properties is presented. Based on self-organized criticality, it ... more A method for obtaining critical properties is presented. Based on self-organized criticality, it drives the system spontaneously to the critical point, providing an e cient way to estimate critical properties. The method is illustrated for Ising spin systems, and despite the small lattice sizes used, it yields critical temperatures and ÿ exponents in good agreement with those available in the literature.
Physics Letters A, 2008
... In fact, they have been applied in several situation such as turbulence [1], [2] and [10], di... more ... In fact, they have been applied in several situation such as turbulence [1], [2] and [10], diffusion on fractals [11], transport of fluid in porous media [12], relaxation to equilibrium in systems (eg, polymers chains and membranes) with long temporal memory [13], [14], [15] and [16 ...
Physical Review Letters, 1994
Physica A: Statistical Mechanics and its Applications, 1999
We present a Monte Carlo study of a linear chain (d = 1) with long-range bonds whose occupancy pr... more We present a Monte Carlo study of a linear chain (d = 1) with long-range bonds whose occupancy probabilities are given by pij = p=r ij (06p61; ¿0) where rij = 1; 2; : : : is the distance between sites. The → ∞ (= 0) corresponds to the ÿrst-neighbor ("mean ÿeld") particular case. We exhibit that the order parameter P∞ equals unity ∀p ¿ 0 for 06 61, presents a familiar behavior (i.e., 0 for p6pc() and ÿnite otherwise) for 1 ¡ ¡ 2, and vanishes ∀p ¡ 1 for ¿ 2. Our results conÿrm recent conjecture, namely that the nonextensive region (06 61) can be meaningfully unfolded, as well as uniÿed with the extensive region (¿ 1), by exhibiting P∞ as a function of p * where (1 − p *) = (1 − p) N * (N * ≡ (N 1− =d − 1)=(1 − =d); N being the number of sites of the chain). A corollary of this conjecture, now numerically veriÿed, is that pc˙(− 1) in the → 1 + 0 limit.
Physica A: Statistical Mechanics and its Applications, 2001
Polyelectrolytes are of great importance in different branches of chemistry and biology. DNA is a... more Polyelectrolytes are of great importance in different branches of chemistry and biology. DNA is a very good example of a polyelectrolyte of biological relevance. In this paper, we describe DNA solutions in the presence of multivalent salts and amphiphiles. After ...
Physica A: Statistical Mechanics and its Applications, 2005
The multifractal lattice Q mf is an object defined on a square using a section parameter z. Q mf ... more The multifractal lattice Q mf is an object defined on a square using a section parameter z. Q mf has been used to study percolation in heterogeneous multifractal structures. In this work we use a group theory approach to explore mathematical properties of Q mf. The self-affine object Q mf is described by the combination of distinct discrete groups: the finite groups of rotation and inversion and the infinite groups of translation and dilation. We address the cell elements of the lattice Q mf using a Cayley tree. We determine the Cartesian coordinates of each cell using group properties in a recursive equation. The rich group structure of Q mf allows an infinite number of distinct tilling for a single z.
Physica A: Statistical Mechanics and its Applications, 2004
In this work we investigate the distribution of shortest paths in percolation systems at the perc... more In this work we investigate the distribution of shortest paths in percolation systems at the percolation threshhold in two dimensions (2D). We study paths from one given point to multiple other points. In oil recovery terminology, the given single point can be mapped to an injection well (injector) and the multiple other points to production wells (producers). In the previously studied standard case of one injection well and one production well separated by Euclidean distance r, the distribution of shortest paths l, P(l|r), shows a power-law behavior with exponent g l =2:14 in 2D. Here we analyze the situation of one injector and an array A of producers. Symmetric arrays of producers lead to one peak in the distribution P(l|A), the probability that the shortest path between the injector and any of the producers is l, while the asymmetric conÿgurations lead to several peaks in the distribution. We analyze conÿgurations in which the injector is outside and inside the set of producers. The peak in P(l|A) for the
Proceedings of the 16th International Congress of the Brazilian Geophysical Society&Expogef
Contents of this paper were reviewed by the Technical Committee of the 16 th International Congre... more Contents of this paper were reviewed by the Technical Committee of the 16 th International Congress of the Brazilian Geophysical Society and do not necessarily represent any position of the SBGf, its officers or members. Electronic reproduction or storage of any part of this paper for commercial purposes without the written consent of the Brazilian Geophysical Society is prohibited.
arXiv: Soft Condensed Matter, 2003
We study a simple model of DNA divalent cationic surfactant complexation. We find that the combin... more We study a simple model of DNA divalent cationic surfactant complexation. We find that the combination of electrostatic and hydrophobic effects leads to a cooperative phenomenon in which as the amphiphile is added to the solution containing DNA, a large fraction of the DNA's charge is neutralized by the condensed divalent cationic surfactants, forming the surfoplex. This binding transition occurs for concentrations that are lower for divalent than for monovalent surfactants. Since the electrostatic strength is larger in the first case and the amount of surfactant lower, we suggest that multivalent amphiphilic molecules would be more efficient than monovalent for transfection.
Proceedings of the 16th International Congress of the Brazilian Geophysical Society&Expogef, 2019
Contents of this paper were reviewed by the Technical Committee of the 16 th International Congre... more Contents of this paper were reviewed by the Technical Committee of the 16 th International Congress of the Brazilian Geophysical Society and do not necessarily represent any position of the SBGf, its officers or members. Electronic reproduction or storage of any part of this paper for commercial purposes without the written consent of the Brazilian Geophysical Society is prohibited.
Journal of Geophysics and Engineering
To eliminate the dependency on a good initial model of the traditional full waveform inversion (F... more To eliminate the dependency on a good initial model of the traditional full waveform inversion (FWI) method, we propose an optimisation method combining a derivative free optimisation method of modified particle swarm with gradient descent search. We worked with the acoustic wave approximation, in two dimensions, with the synthetic Marmousi velocity model as the test case. We were able to obtain a high-precision inversion of this model, comparable to traditional FWI methods, with the distinct advantage of not using an initial model close to the global optimal, as would usually be required. For this result, we used a progressive inversion scheme by consecutive layers, and a modified particle swarm optimisation algorithm where we introduced the gradient of the misfit function as a local search guide, and other regularization terms.
Proceedings of the 16th International Congress of the Brazilian Geophysical Society&Expogef
Contents of this paper were reviewed by the Technical Committee of the 16 th International Congre... more Contents of this paper were reviewed by the Technical Committee of the 16 th International Congress of the Brazilian Geophysical Society and do not necessarily represent any position of the SBGf, its officers or members. Electronic reproduction or storage of any part of this paper for commercial purposes without the written consent of the Brazilian Geophysical Society is prohibited.
Proceedings of the 16th International Congress of the Brazilian Geophysical Society&Expogef
Contents of this paper were reviewed by the Technical Committee of the 16 th International Congre... more Contents of this paper were reviewed by the Technical Committee of the 16 th International Congress of the Brazilian Geophysical Society and do not necessarily represent any position of the SBGf, its officers or members. Electronic reproduction or storage of any part of this paper for commercial purposes without the written consent of the Brazilian Geophysical Society is prohibited.
SEG Technical Program Expanded Abstracts 2019
Physica A: Statistical Mechanics and its Applications
Using the small-world approach we suggest a network model for the economy. Our basic assumption i... more Using the small-world approach we suggest a network model for the economy. Our basic assumption is that the economic agents prefer to make business with the big business. This assumption makes the preferential attachment the main mechanism for the evolution of the economic network. We hypothesize that the connectivity of the economic network should reflect the wealth distribution of the
Nonlinear Processes in Geophysics
We employ the detrended fluctuation analysis (DFA) technique to investigate spatial properties of... more We employ the detrended fluctuation analysis (DFA) technique to investigate spatial properties of an oil reservoir. This reservoir is situated at Bacia de Namorados, RJ, Brazil. The data correspond to well logs of the following geophysical quantities: sonic, gamma ray, density, porosity and electrical resistivity, measured in 56 wells. We tested the hypothesis of constructing spatial models using data from fluctuation analysis over well logs. To verify this hypothesis, we compare the matrix of distances of well logs with the differences in DFA exponents of geophysical quantities using a spatial correlation function and the Mantel test. Our data analysis suggests that the sonic profile is a good candidate for representing spatial structures. Then, we apply the clustering analysis technique to the sonic profile to identify these spatial patterns. In addition, we use the Mantel test to search for correlations between DFA exponents of geophysical quantities.
Physica A: Statistical Mechanics and its Applications
ABSTRACT