Lipases from different sources have distinct properties, such as specificity, stability and optimal operational conditions. Moreover, different conditions of lipase production may alter these enzyme properties. Therefore, the aims of this study were related to the evaluation of lipase activity of Yarrowia lipolytica IMUFRJ 50682 (isolated from Baía de Guanabara, Brazil) produced under submerged...

An arithmetic sequence a(n) = {a+nx : x ∈ Z} (0 6 a < n) with weight λ ∈ C is denoted by 〈λ, a, n〉. For two finite systems A = {〈λs, as, ns〉}s=1 and B = {〈μt, bt,mt〉}t=1 of such triples, if ∑ ns|x−as λs = ∑ mt|x−bt μt for all x ∈ Z then we say that A and B are covering equivalent. In this paper we characterize covering equivalence in various ways, our characterizations involve the Γ-function, t...

superconductor fault current limiter (sfcl) is an effective device to suppress high fault currents. this paper presents a comparative study of resistive and inductive fault current limiters from transient stability point of view.  appropriate location and type of the limiters in a hv substation is selected by a qualitative approach based on the equal area criterion. study system is simulated by...

Fuzzy control systems have had various applications in a wide range of science and engineering in recent years. Since an unstable control system is typically useless and potentially dangerous, stability is the most important requirement for any control system (including fuzzy control system). Conceptually, there are two types of stability for control systems: Lyapunov stability (a special case ...

In this paper numerical results are reviewed ([13]) that demonstrate that common second-order operator-splitting methods can exhibit instabilities when integrating the Brusselator equations out to moderate times of about seven periods of oscillation. These instabilities are manifested as high wave number spatial errors. In this paper we further analyze this problem and present a theorem for sta...

aggregate stability is an important soil property because it dictates how strongly a soil can resist water erosion. the objectives in this study were: (1) to compare the stability of six soil aggregate size fractions, primarily to determine if aggregate stability varies with aggregate size, and (2) to determine with which aggregate size fraction the stability of most soils would be different fr...

in this work, we present a new strategy of direct adaptive control denoted: Extended minimal controller synthesis (EMCS). This algorithm is designed for an induction motor, which includes both electrical and mechanical dynamics under the assumptions of linear magnetic circuits. The main motivation of the EMCS control is to enhance the robustness of the MRAC algorithms, i.e. the rejection of bou...