Liquid-liquid extraction of transition metal cations by glyoximes and their macrocyclic glyoxime ether derivatives

Liquid-liquid extraction of various alkalis (Li+, Na +, K+, and Cs+), transition metals (Co 2+, Ni2+, Cu2+, Zn2+, Cd 2+, and Hg2+), and Pb2+ cations with phenylglyoxime (L1), p-tolylglyoxime (L2), N′-(4′-Benzo[15-crown-5]) phenylaminoglyoxime (L3), and N′-(4′-Benzo[15-crown-5])-p- tolylaminoglyoxime (L4) from the aqueous phase into the organic phase was carried out. For comparison, the corresponding two glyoximes and their macrocyclic glyoxime ether derivatives were also examined. Crown ether groups having ligands (L3, L4) carry especially Na+ cation from aqueous phase to organic phase. The extraction equilibrium constants (K ex) for complexes of ligands with Cu2+ and Hg2+ metal picrates between dichloromethane and water have been determined at 25°C. The values of the extraction constants (log K ex) were determined to be 12.27, 13.37, 12.94, and 12.39 for Cu2+ and 10.29, 10.62, 11.53, and 11.97 for Hg2+ with L1-L4, respectively. © 2013 Nazan Karapinar et al

Iterative approximation of fixed points of Prešić operators on partial metric spaces

Please read abstract in the article.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1522-2616hb2017Mathematics and Applied Mathematic

Multidimensional Fixed-Point Theorems in Partially Ordered Complete Partial Metric Spaces under ()-Contractivity Conditions

We study the existence and uniqueness of coincidence point for nonlinear mappings of any number of arguments under a weak ()-contractivity condition in partial metric spaces. The results we obtain generalize, extend, and unify several classical and very recent related results in the literature in metric spaces (see Aydi et al. (2011), Berinde and Borcut (2011), Gnana Bhaskar and Lakshmikantham (2006), Berzig and Samet (2012), Borcut and Berinde (2012), Choudhury et al. (2011), Karapınar and Luong (2012), Lakshmikantham and Ćirić (2009), Luong and Thuan (2011), and Roldán et al. (2012)) and in partial metric spaces (see Shatanawi et al. (2012))