A GRASP based on DE to solve single machine scheduling problem with SDST

When handling combinatorial optimization problems, we try to get the optimal arrangement of discrete entities so that the requirements and the constraints are satisfied. These problems become more and more important in various industrial and academic fields. So, over the past years, several techniques have been proposed to solve them. In this paper, we are interested in the single machine scheduling problem with Sequence-Dependent Setup Times, which can be solved through different approaches. We present a hybrid algorithm which combines Greedy Randomized Adaptive Search Procedure and Differential Evolution for tackling this problem. Our algorithm is tested on benchmark instances from the literature. The computational experiments prove the efficiency of this algorithm.     

On non-associative anisotropic finite plasticity fully coupled with isotropic ductile damage for metal forming

In this work, non-associative finite strain anisotropic elastoplasticity fully coupled with ductile damage is considered using a thermodynamically consistent framework. First, the kinematics of large strain based on multiplicative decomposition of the total transformation gradient using the rotating frame formulation, is recalled and different objective derivatives defined. By using different anisotropic equivalent stresses (quadratic and non-quadratic) in yield function and in plastic potential, the evolution equations for all the dissipative phenomena are deduced from the generalized normality rule applied to the plastic potential while the consistency condition is still applied to the yield function. The effect of the objective derivatives and the equivalent stresses (quadratic or non-quadratic) on the plastic flow anisotropy and the hardening evolution with damage is considered. Numerical aspects mainly related to the time integration of the fully coupled constitutive equations are discussed. Applications are made to the AISI 304 sheet metal by considering different loading paths as tensile, shear, plane tensile and bulge tests. For each loading path the effect of the rotating frame, the equivalent stress (quadratic or non-quadratic) and the normality rule (with respect to yield function or to the plastic potential) are discussed on the light of some available experimental results.     

In vitro cytotoxic and antiviral activities of Ficus carica latex extracts

The latex of fig fruit (Ficus carica) is used in traditional medicine for the treatment of skin infections such as warts and also diseases of possible viral origin. Five extracts (methanolic, hexanic, ethyl acetate, hexane-ethyl acetate (v/v) and chloroformic) of this species were investigated in?vitro for their antiviral potential activity against herpes simplex type 1 (HSV-1), echovirus type 11 (ECV-11) and adenovirus (ADV). To evaluate the capacity of the extracts to inhibit the replication of viruses, the following assays were performed: adsorption and penetration, intracellular inhibition and virucidal activity. Observation of cytopathic effects was used to determine the antiviral action. The hexanic and hexane-ethyl acetate (v/v) extracts inhibited multiplication of viruses by tested techniques at concentrations of 78 μg mL(-1). These two extracts were possible candidates as herbal medicines for herpes virus, echovirus and adenovirus infectious diseases. All extracts had no cytotoxic effect on Vero cells at all tested concentrations.     

Complex Formation of Some Tetraamido-type Calix[4]arene Derivatives Detected by Vibrational Spectroscopy

Abstract

Dibenzo-14-crown-4 alcohols are shown to aggregate in chloroform by the formation of hydrogen-bonded dimers. Structural variations between crown ether alcohols significantly affect the degree of dimerization. This self-association is of relevance for understanding the complexation and extractive properties of these and related macrocycles.     

Synthesis and cation complexation of calix[4]azacrowns and a spirobiscalix[4]azacrown

The synthesis and complexation properties of three new derivatives, one spirobiscalix[4]azacrown (1) and two calix[4]azacrown (2 and 3), are reported. Complexation studies of the three ligands toward transition and heavy metal cations have been carried out and monitored by UV absorption spectrophotometry in acetonitrile. Mononuclear complexes were detected for all complexes, whereas binuclear species (M₂L) were also formed in the case of ligand 1 with Cu²⁺ and Pb²⁺. The extraction properties of 1, 2 and 3 toward Cu²⁺, Zn²⁺, Pb²⁺, Ag²⁺ and Cd²⁺ are also reported. The results showed that complexation is the main factor affecting extraction with ligands 2 and 3, while with ligand 1 it is not.