A method, involving the use of an advanced paper ionophoretic technique is described for the study of equilibria in mixed complex systems in solution. The method is based on the migration of a spot of metal ion, with the complexants added in the background electrolyte. The concentration of one of the complexants, methylcysteine, is kept constant while that of the second ligand, cysteine, is var...

The Schiff base ligand 5-bromo-3-(((8-hydroxy-2-methylquinolin-7-yl)methylene)hydrazono)indolin-2-one (BHMQMHI) was prepared via condensation of 5-bromo-3-hydrazonoindolin-2-one and 7-formyl-8-hydroxy-2-methylquinoline and its Co(II), Ni(II), Cu(II), Zn(II), Cd(II), and Hg(II) complexes have been synthesized and characterized by elemental analysis, conductance data, magnetic susceptibility meas...

The stability constants of Cu'(l1) glycine complexes in 0.7 M NaC104 and 0.7M NaN03 media were evaluated using Cu ( 1 1 ) ion selective electrode. The stability constant data are consistent with earlier reports of other metal ion complexes of glycine. The distribution level of Cu ( 1 1 ) glycine complexes in presence of other complexing ligands of marine environment has also been numerically ev...

Stability parameters for stabilized methods in uids are suggested. The computation of the largest eigenvalue of a generalized eigenvalue problem replaces controversial de nitions of element diameters and inverse estimate constants, used heretofore to compute these stability parameters. The design is employed in the advective-di usive model, incompressible Navier-Stokes equations and the Stokes ...

We prove stable versions of trace theorems on the sphere in L with optimal constants, thus obtaining rather precise information regarding near-extremisers. We also obtain stability for the trace theorem into L for q > 2, by combining a refined Hardy–Littlewood–Sobolev inequality on the sphere with a duality-stability result proved very recently by Carlen. Finally, we extend a local version of C...

The complexation ability of DOTA analogs bearing one methylenephosphonic (DO3AP) or methylenephosphinic (DO3AP(PrA) and DO3AP(ABn)) acid pendant arm toward scandium was evaluated. Stability constants of their scandium(iii) complexes were determined by potentiometry combined with (45)Sc NMR spectroscopy. The stability constants of the monophosphinate analogues are somewhat lower than that of the...

For a general class of saddle point problems sharp estimates for Babuška’s inf-sup stability constants are derived in terms of the constants in Brezzi’s theory. In the finite-dimensional Hermitian case more detailed spectral properties of preconditioned saddle point matrices are presented, which are helpful for the convergence analysis of common Krylov subspace methods. The theoretical results ...

1. The effect of a perturbation on the solutions of a linear system of differential equations can be studied by means of the variation of constants formula. The nonlinear variation of constants formula of Alekseev [l] has been used to obtain various results on the effect of a perturbation on the solutions of a nonlinear system; see, for example [2], [3], [5]. In most of these results, the trivi...

the acid-base equilibrium of lorazepam was studied by means of potentiometry andmultiwavelengths spectrophotometry. the stoichiometric equilibrium constants were determinedat 25 °c and constant ionic strength 0.1 mol l-1 (nacl). the acidity constants pk1=1.58±0.05and pk2=11.67±0.07 were found by potentiometry, and pk1=1.54±0.02 and pk2=11.61±0.03 bymulti-wavelengths spectrophotometry. potentiom...

the complexation reaction between hydroxyl ammonium (honh3+ ) cation with 18-crown-6 (18c6) ligand was studied in dimethylsulfoxide – water (dmso-h2o), methanol – water (meoh-h2o) and dimethylformamid – methanol (dmf-meoh), binary solutions at different temperatures using conductometric method. the obtained results show that the stoichiometry of the complex formed between honh3+ cation with (18...