Adsorption of cations Al, Zn, Fe, Cr and Pb from aqueous solution of hydrogen peroxide using IR-120 cation-exchange resin was studied. The removal percentage of the cations was examined by varying experimental conditions (such as pH of the hydrogen peroxide solution, temperature, contact time and dosage of adsorbent) i...

A proton NMR method for the determination of the solvation numbers of alkaline earth cations with dimethylsulfoxide (DMSO) in nitromethane as diluent is described. The method is based on the monitoring of the resonance frequency of DMSO protons as a function of DMSO to metal ion mole ratio while keeping the metal ion concentration constant. The average solvation number of cations at any...

The ability of the pair distribution function (PDF) analysis of total scattering (TS) from a powder to determine the local ordering in ferroelectric PZN (PbZn1/3Nb2/3O3) has been explored by comparison with a model established using single-crystal diffuse scattering (SCDS). While X-ray PDF analysis is discussed, the focus is on neutron diffraction results because of the greater extent of the da...

the mechanism by which bi-and trivalent cations affect human liver phosphatidatephosphohydrolase (pap) activity was investigated. bivalent cations up to 1 mm increased pap activity whereas at higher concentrations the activity of the enzyme decreased. the stimulatory concentration for trivalent cations such as al3+ and cr3+, however, was much lower being 2 m m and 1 m m, respectively. all catio...

adsorption of cations al, zn, fe, cr and pb from aqueous solution of hydrogen peroxide using ir-120 cation-exchange resin was studied. the removal percentage of the cations was examined by varying experimental conditions (such as ph of the hydrogen peroxide solution, temperature, contact time and dosage of adsorbent) in a stirred-batch system. under the optimal conditions (ph=1, t=25oc, contact...

In this research new adsorbents were prepared by modification of surfactant-coated g-alumina with three ligands; 1-(2-pyridylazo)-2-naphtol (PAN), dithizone (HDZ) and dimetyl golyoxime (DMG). The adsorbents were used for removal and pre-concentration of Pb+2, Cd+2, Ni+2, Cu+2, Co+2. Aqueous solutions of the me...

in this research new adsorbents were prepared by modification of surfactant-coated g-alumina with three ligands; 1-(2-pyridylazo)-2-naphtol (pan), dithizone (hdz) and dimetyl golyoxime (dmg). the adsorbents were used for removal and pre-concentration of pb+2, cd+2, ni+2, cu+2, co+2. aqueous solutions of the metal ions were passed through a column filled with the adsorbent and the retained catio...

This study reveals that, in strong coulomb coupling regime, bending a straight and fully overcharged DNA (up to its ‘maximal acceptance’ by multivalent cations) to a circle releases some of the adsorbed (correlated) cations but still remains fully overcharged. This phenomenon seems to be inherent to the minimum energy state of a DNA. By definition, the total electrostatic potential energy of a ...

Anomalous small angle scattering measurements have been applied to diluted solutions of anionic polyacrylates decorated by specifically-interacting Pb2+ cations, revealing partial collapse of the polyacrylate into pearl-like subdomains with a size on the order of a few nanometers. From the pure-resonant scattering contribution of the Pb2+ cations, and from subsequent analysis of the resonant-in...

K+ currents were recorded in squid axons internally perfused with impermeant electrolyte. Total absence of permeant ions inside and out leads to an irreversible loss of potassium conductance with a time constant of approximately 11 min at 8 degrees C. Potassium channels can be protected against this effect by external K+, Cs+, NH4+, and Rb+ at concentrations of 100-440 mM. These experiments sug...