using uv-vis spectrophotometric method, the formation constant for interaction of fe2+(aq) ion with l-alaninewas experimentally studied at ph = 4.1 ± 0.01 (50mm of potassium hydrogen phthalate buffer), ionic strengthof 0.1m potassium nitrate and at 5 different temperatures 15,20, 25,30 and 35 t. the optical absorption spectraof mixtures containing considered cation and l-alanine were analyzed b...

in this article, theoretical studies on the selective complexation of the halide ions (f¯, cl¯ and br¯) and ion pairs (na+f¯, na+cl¯ and na+br¯) with the cyclic nano-hexapeptide (cp) composed of l-proline have been performed in the gas phase. in order to calculate the dispersion interaction energies of the cp and ions, dft-d3 calculations at the m05-2x-d3/6-31g(d) level was employed. based on t...

the protonation constant values of salicylic and 5-nitrosalicylic acid werestudied by a combinationof spectrophotometric and potentiometric methods at 25 °c in wide range of ionic strength. the ionicstrength of solutions was kept constant by sodium perchlorate as background electrolyte at 0.10 to 3.0 moldm-3. potentiometer was calibrated according to gran method at each of ionic strength. the p...

a thermodynamic study on the interaction between zinc ion (zn2+) and human growth hormone(hgh) was studied at two temperatures of 27c and 37c in aqueous solution using an isothermal titrationcalorimetry. it was found that there is a set of three identical and non-interacting binding sites for zn2+ ions. the intrinsic dissociation equilibrium constant and the molar enthalpy of binding are 1.54...

the interaction between holo-transferin (htf) and colchicine (col) was investigated in the present of pb +2 ions under physiological conditions by using synchronous fluorescence spectra. the synchronous fluorescence spectra show a slight change of tryptophan residue micro-environment. synchronous fluorescence spectra show that the structure of the tyrosine residue environment was altered by int...

vapor-liquid equilibrium in nh3-co2-h2o system at high pressures has been studied. the uniquac-nrf model for this system was extended by using the goppert 4 maurer reported datas. since the system contains molecules and ionic species the binary interaction parameters considered, where those are of molecule-molecule, molecule-ion and ion-ion types. these interaction parameters are taken as const...

the major foible of dental ceramics is their brittle nature. therefore, the producers of these materials have focused on the “strength” issue. a method of increasing strength is ion exchange on porcelain surface which leads to formation of a compressive crust that opposing forces should overcome before developing a crack. in current study, ion exchange in two types of porcelain, ceramco ii whic...