Bem vindo ao site do Grupo de Sistemas Complexos do Instituto de Física da Universidade Federal Fluminense.
O grupo de Sistemas Complexos do Instituto de Física da UFF já tem tradição como um dos mais importantes em simulações de sistemas estatísticos, no Brasil e no exterior, tendo já formado vários pesquisadores que ocupam posições em várias instituições de pesquisa no país. O caráter interdisciplinar do grupo é um fator de atração de estudantes, tanto do Brasil quanto do exterior, em especial da América do Sul. Já há vários anos que o grupo se reúne semanalmente para apresentação e discussão do andamento de seus vários projetos de pesquisa.
Novidades
Estudantes, professores e técnicos da UFF agora tem acesso ao Sun Learning Connection, através do programa Sun Academic Initiative. Os professores Thadeu Penna e Antônio Costa Jr. fizeram a solicitação que foi rapidamente aprovada pela Sun. O ambiente Sun Learning Connection oferece vários cursos on-line de OpenSolaris, Java, Perl, Administração Unix, etc. Além dos cursos, os interessados podem obter descontos significativos (até 70%) nos exames de certificação.
Seminários
Resumo: The global response of the sudden changes in the interface growth dynamics is discussed using models of the Kardar-Parisi-Zhang (KPZ) and Villain-Lai-Das Sarma (VLDS) classes during their growth regimes in 2 + 1 dimensions. We introduce scaling arguments and present simulation results to predict the relaxation of the difference in the squared global roughness of the perturbed and the unperturbed interfaces. Following the same lines of previous works [1-3] discussed in previous talk, we propose an asymptotic scaling which includes the temperature effects in the scaling of the correlation length. Interestingly, our results indicate a crossover from a dynamic where the plateau formation prevails to a dynamic with the scaling of the correlation length of the corresponding VLDS model [4]. Finally, we discuss our results making a parallel with experiments for KPZ-VLDS case that may be viewed as a potential application.
[1] Y.-L. Chou, M. Pleimling, and R. K. P. Zia, Phys. Rev. E 80, 061602 (2009)
[2] Y.-L. Chou and M. Pleimling, J. Stat. Mech. P08007 (2010)
[3] T. A. de Assis and F. D. A. Aarão Reis, Phys. Rev. E 89, 062405 (2014)
[4] F. D. A. Aar\~{a}o Reis, Phys. Rev. E 81 041605 (2010)
Resumo: A thermodynamical formalism is developed for a system of interacting particles under overdamped motion, which is analyzed within the framework of nonextensive statistical mechanics. It amounts to express the interaction energy of the system in terms of a temperature theta, conjugated to a generalized entropy s_q, with q=2. Since theta assumes much higher values than those of typical room temperatures T«theta, the thermal noise can be neglected for this system (T/theta~=0). The introduction of a work term delta W which, together with the heat contribution (delta Q = theta ds_q), allows for the statement of a proper energy conservation law that is analogous to the first law of thermodynamics. These definitions lead to the derivation of an equation of state and to the characterization of s_q-adiabatic and theta-isothermic transformations. On this basis, a Carnot cycle is constructed, whose efficiency is shown to be \eta=1-(theta_2/theta_1), where theta_1 and theta_2 are the effective temperatures of the two isothermic transformations, with theta_1>theta_2. All results presented are consistent with those of standard thermodynamics for T>0, opening the possibility for further physical consequences.
Parcerias
Apoio
