Solvent extraction of permanganates (Na, K) by 18-crown-6 ether from water into 1,2-dichloroethane: elucidation of an extraction equilibrium based on component equilibria.
Ion-pair formation constants (K(MLA) mol(-1) dm(3)) of Na(+)- and K(+)-18-crown-6 ether (18C6) complexes with MnO(4)(-) in water (w) were determined potentiometrically at 25 degrees C. Simultaneously, extraction constants (K(ex) mol(-2) dm(6)) of the permanganates with 18C6 from w into 1,2-dichloroethane at 25 degrees C were obtained from the spectrophotometric determination of distribution ratios of the permanganates. These K(ex) values were divided into K(MLA) and other three component equilibrium constants and thereby extraction-selectivity and -ability were discussed in comparison with corresponding metal picrate-18C6 extraction systems reported before.
Potentiometric Determination of the Ion-Pair Formation Constant of a Univalent Cation-Neutral Ligand Complex with an Anion in Water Using an Ion-Selective Electrode
formation constants of univalent metal-crown ether complexes with anions in water. This is because stabilities of the crown ether-complex cations are low in water, where the concentration of the uncomplexed metal ion is not negligible as compared with the concentration of the crown ether-complexed one. Recently, the ion-pair formation constants of alkali metal-18-crown-6 (18C6) and -its derivative complexes with picrate (Pic–) in a water phase have been determined systematically by solvent extraction.1,2 In the present study, a theoretical equation has been derived to determine newly the ion-pair formation constant (KMLX) of a crown ether-complexed metal ion (ML+) with an anion (X–) by potentiometry with a M+ion selective electrode (ISE). Then the ion-pair formation constant (KMX) of NaPic and the KMLX values of Na(18C6)Pic and Na(18C6)ClO4 were measured in water at 25 ̊C.
Application of Automatic Tracking Correlation Filtering in Motored Spindle Dynamic Balancing
According to the information characteristics of the dynamic imbalance signal and the definition of correlation function,the principles and algorithm of relevant filter with automatic tracking is given.In labview development system,based on the principles of relevant filter with automatic tracking,the graphics programming of extracting the dynamic imbalance signal is developed.With this programming,the vibration signal including different frequency harmonic signals and noise is processed by simulation and on-site experiment.The results show that: through relevant filter with automatic tracking,the dynamic imbalance signal under different rotating speed can be extracted accurately,and it can meet the requirement of motored spindle dynamic balancing measurement.