https://repositorio.ufba.br/handle/ri/2094 Mon, 04 May 2026 09:15:00 GMT 2026-05-04T09:15:00Z https://repositorio.ufba.br/handle/ri/17370 Título: Annealed Ising model with site dilution on self-similar structures Autor(es): Silva, V. S. T.; Andrade, Roberto Fernandes Silva; Salinas, S. R. Abstract: We consider an Ising model on the triangular Apollonian network (AN), with a thermalized distribution of vacant sites. The statistical problem is formulated in a grand canonical ensemble, in terms of the temperature T and a chemical potential μ associated with the concentration of active magnetic sites. We use a well-known transfer-matrix method, with a number of adaptations, to write recursion relations between successive generations of this hierarchical structure. We also investigate the analogous model on the diamond hierarchical lattice (DHL). From the numerical analysis of the recursion relations, we obtain various thermodynamic quantities. In the μ→∞ limit, we reproduce the results for the uniform models: in the AN, the system is magnetically ordered at all temperatures, while in the DHL there is a ferromagnetic-paramagnetic transition at a finite value of T. Magnetic ordering, however, is shown to disappear for sufficiently large negative values of the chemical potential. Tipo: Artigo de Periódico Wed, 01 Jan 2014 00:00:00 GMT https://repositorio.ufba.br/handle/ri/17370 2014-01-01T00:00:00Z https://repositorio.ufba.br/handle/ri/17368 Título: Height distribution of equipotential lines in a region confined by a rough conducting boundary Autor(es): Castro, C. P. de; Assis, Thiago Albuquerque de; Castilho, Caio Mário Castro de; Andrade, Roberto Fernandes Silva Abstract: This work considers the behavior of the height distributions of the equipotential lines in a region confined by two interfaces: a cathode with an irregular interface and a distant flat anode. Both boundaries, which are maintained at distinct and constant potential values, are assumed to be conductors. The morphology of the cathode interface results from the deposit of 2 × 104 monolayers that are produced using a single competitive growth model based on the rules of the Restricted Solid on Solid and Ballistic Deposition models, both of which belong to the Kadar–Parisi–Zhang (KPZ) universality class. At each time step, these rules are selected with probability p and q = 1 − p. For several irregular profiles that depend on p, a family of equipotential lines is evaluated. The lines are characterized by the skewness and kurtosis of the height distribution. The results indicate that the skewness of the equipotential line increases when they approach the flat anode and this increase has a non-trivial convergence to a delta distribution that characterizes the equipotential line in a uniform electric field. The morphology of the equipotential lines is discussed; the discussion emphasizes their features for different ranges of p that correspond to positive, null and negative values of the coefficient of the non-linear term in the KPZ equation. Tipo: Artigo de Periódico Wed, 01 Jan 2014 00:00:00 GMT https://repositorio.ufba.br/handle/ri/17368 2014-01-01T00:00:00Z https://repositorio.ufba.br/handle/ri/17296 Título: Involutive constrained systems and Hamilton-Jacobi formalism Autor(es): Bertin, M. C.; Pimentel, B. M.; Valcárcel, C. E. Abstract: In this paper, we study singular systems with complete sets of involutive constraints. The aim is to establish, within the Hamilton-Jacobi theory, the relationship between the Frobenius’ theorem, the infinitesimal canonical transformations generated by constraints in involution with the Poisson brackets, and the lagrangian point (gauge) transformations of physical systems. Tipo: Artigo de Periódico Wed, 01 Jan 2014 00:00:00 GMT https://repositorio.ufba.br/handle/ri/17296 2014-01-01T00:00:00Z https://repositorio.ufba.br/handle/ri/17294 Título: Hybrid platforms of graphane–graphene 2D structures: prototypes for atomically precise nanoelectronics Autor(es): Mota, F. de B.; Rivelino, Roberto; Medeiros, P. V. C.; Mascarenhas, A. J. S.; Castilho, Caio Mário Castro de Abstract: First-principles calculations demonstrate that line/ribbon defects, resulting from a controlled dehydrogenation in graphane, lead to the formation of low-dimensional electron-rich tracks in a monolayer. The present simulations point out that hybrid graphane–graphene nanostructures exhibit important elements, greatly required for the fabrication of efficient electronic circuits at the atomic level. Tipo: Artigo de Periódico Wed, 01 Jan 2014 00:00:00 GMT https://repositorio.ufba.br/handle/ri/17294 2014-01-01T00:00:00Z