26,155 research outputs found

    Corrections to Finite Size Scaling in Percolation

    Full text link
    A 1/L-expansion for percolation problems is proposed, where L is the lattice finite length. The square lattice with 27 different sizes L = 18, 22 ... 1594 is considered. Certain spanning probabilities were determined by Monte Carlo simulations, as continuous functions of the site occupation probability p. We estimate the critical threshold pc by applying the quoted expansion to these data. Also, the universal spanning probability at pc for an annulus with aspect ratio r=1/2 is estimated as C = 0.876657(45)

    Identificação de deficiências nutricionais do guaraná.

    Get PDF
    Procuraram-se evidenciar os sintomas de deficiência nutricional do guaraná. Com este objetivo, plantas de guaraná foram cultivadas em substrato de areia lavada e supridas com solução nutritiva completa (todos os nutrientes) e com soluções de um elemento omitido para teste de deficiência. Quando os sintomas foram constatados, realizou-se a documentação fotográfica e a interpretação visual das deficiências. Assim, foi possível elaborar uma chave indicadora da carência de N, P, K, Ca, Mg, S, Cu, Mn, Zn, Fe, B e Mo em plantas de guaraná.bitstream/item/33534/1/CPATU-CirTec13.pd

    Self-Similar Collapse of Scalar Field in Higher Dimensions

    Get PDF
    This paper constructs continuously self-similar solution of a spherically symmetric gravitational collapse of a scalar field in n dimensions. The qualitative behavior of these solutions is explained, and closed-form answers are provided where possible. Equivalence of scalar field couplings is used to show a way to generalize minimally coupled scalar field solutions to the model with general coupling.Comment: RevTex 3.1, 15 pages, 3 figures; references adde

    FINITE SIZE SCALING FOR FIRST ORDER TRANSITIONS: POTTS MODEL

    Full text link
    The finite-size scaling algorithm based on bulk and surface renormalization of de Oliveira (1992) is tested on q-state Potts models in dimensions D = 2 and 3. Our Monte Carlo data clearly distinguish between first- and second-order phase transitions. Continuous-q analytic calculations performed for small lattices show a clear tendency of the magnetic exponent Y = D - beta/nu to reach a plateau for increasing values of q, which is consistent with the first-order transition value Y = D. Monte Carlo data confirm this trend.Comment: 5 pages, plain tex, 5 EPS figures, in file POTTS.UU (uufiles

    Speeding Up Computer Simulations: The Transition Observable Method

    Full text link
    A method is presented which allows for a tremendous speed-up of computer simulations of statistical systems by orders of magnitude. This speed-up is achieved by means of a new observable, while the algorithm of the simulation remains unchanged.Comment: 20 pages, 6 figures Submitted to Phys.Rev.E (August 1999) Replacement due to some minor change

    Produção integrada de frutas.

    Get PDF
    Elaborado com a colaboração da equipe técnica de Produção Integrada de Frutas da Embrapa Semi-Árido: Flávia Rabelo Barbosa, Joston Simão de Assis, Paulo Roberto Coelho Lopes, Selma Cavalcanti Cruz de Holanda Tavares
    corecore