the removal of copper (ii), zinc (ii), and chromium (iii) from wastewater by carrot residues(cr) was investigated to evaluate cation exchange capacity. the effects of solution ph and co- ions werestudied in batch experiments. adsorption equilibria were initially rapidly established, and then decreasedmarkedly after 10 min. column experiments were carried out in a glass column filled with cr toe...

a proton nmr method for the drtermination of salvation numbers of alkaline earth cations with hexamethyl phosphoramide (hmpa) in nitromethane (nm) as diluents is described. the method is based on monitoring the resonance frequency of hmpa protons as a function of hmpa / metal ion molar ratio at constant metalion concentration. the average salvation number of cations,  , at any hmpa / metal ion ...

Graphene-wrapped FeF3 nanocrystals (FeF3/G) have been successfully fabricated for the first time by a vapour-solid method, which can be generalized to synthesize other metal fluorides. The as-synthesized FeF3/G delivers a charge capacity of 155, 113, and 73 mA h g(-1) at 104, 502, and 1040 mA g(-1) in turn, displaying superior rate capability to bare FeF3. Moreover, it exhibits stable cyclabili...

The synthesis and cation-binding properties of a series of Calixarene derivatives possessing alkyl chain groups, ester groups and crown ether rings have been investigated. The syntheses of Calix[4]arene crown ethers and Calix[6]arene derivatives possessing alkyl chain, ester group and crown ether ring have been described. In order to evaluate their monovalent cation binding abilities, solvent e...

In concentration of hydrogen peroxide, first, the solution should be quite pure, and then, it concentrate with methods such as vacuum distillation and cooling crystallization, because impurities in the hydrogen peroxide solution in high concentrations are causing decomposition of this substance; that is very dangerous. The purpose of this article is separation of chromium and magne...

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...

-The conditions under which an exchanger phase will behave as an ideal mixture are established from thermodynamic principles. It is shown that, if a stoichiometric cation-exchange reaction is reversible, the exchanger phase will exhibit ideal behavior if the Vanselow selectivity coefficient is independent of the exchanger composition. This criterion is applied to some recently published data fo...

The alkali metal ion affinity of guanine quadruplexes has been studied using dispersion-corrected density functional theory (DFT-D). We have done computational investigations in aqueous solution that mimics artificial supramolecular conditions where guanine bases assemble into stacked quartets as well as biological environments in which telomeric quadruplexes are formed. In both cases, an alkal...

An object-oriented approach to the analysis and design of metal forming and directional solidi cation processes is presented. A number of speci c ideas are introduced on how a deformation or a solidi cation process can be partitioned into subproblems that can be independently developed and tested in the form of class hierarchies. Class development based on mathematical and/or physical arguments...