Importance of growth form on production of hybrid antibiotic byStreptomyces lividans TK21 by fed-batch and continuous fermentation

A fermentation strategy, based on the controlled feeding of growthlimiting nutrients in order to maintain metabolic activity for extended periods, has been examined in the case of the production of a hybrid antibiotic by a transformed strain ofStreptomyces lividans TK21. The fed-batch operation did not improve the results obtained with batch operation. Continuous cultures on defined medium showed stable levels of biomass concentration, but antibiotic production ceased when continuous operation was started. The results obtained indicate the critical influence that morphology of the cell aggregates has on metabolic activity. The antibiotic is produced only in culture conditions providing growth in compact mycelial pellets.     

Tuning the optical properties of Prussian blue-like complexes

The rational design of the organic ligand allows to finely tune the degree of delocalization of mixed-valence Prussian blue-like molecules.     

Photodegradation kinetics of some indolecarboxylic acids and their regulation effects on plant growth (groundnut and haricot bean)

Indolecarboxylic acids belong to the auxins group. They constitute a class of phytohormones, which play an important role in plant growth. This paper deals with the kinetics of six indolecarboxylic acids and their regulation effects on the growth of groundnut (Arachis hypogea) and haricot bean (Phaseolus vulgaris). The results obtained enabled us to establish a relationship between photodegradation rate constants and their regulation properties on the growth of these two plants. The paper shows that the compounds yielding the highest photodegradation rates were efficient growth regulators. In this regard, a few explanations are provided.     

Improved semilocal convergence analysis in Banach space with applications to chemistry

We present a new semilocal convergence analysis for Secant methods in order to approximate a locally unique solution of a nonlinear equation in a Banach space setting. Our analysis includes the computation of the bounds on the limit points of the majorizing sequences involved. Under the same computational cost on the parameters involved our convergence criteria are weaker and the error bounds more precise than in earlier studies. A numerical example is also presented to illustrate the theoretical results obtained in this study.     

Second derivative free sixth order continuation method for solving nonlinear equations with applications

In this paper, we deal with the study of convergence analysis of modified parameter based family of second derivative free continuation method for solving nonlinear equations. We obtain the order of convergence is at least five and especially, for parameter \(\alpha =2\) sixth order convergence. Some application such as Max Planck’s conservative law, multi-factor effect are discussed and demonstrate the efficiency and performance of the new method (for \(\alpha =2\)). We compare the absolutely value of function at each iteration \(|f(x_n)|\) and \(|x_n-\xi |\) with our method and Potra and Pták method [1], Kou et al. method [2]. We observed that our method is more efficient than existing methods. Also, the Dynamics of the method are studied for a special case of the parameter in convergence.