Polymer dissolution was described by chain reptation incorporated into penetrant transport. The penetrant concentration field was divided into three regimes which delineate three different transport processes. Solvent penetration through the polymer was modeled to occur as a consequence of a diffusional flux and an osmotic pressure contribution. Species momentum balances were written that coupl...

This study investigated the optimum conditions for the leaching of manganese-rich iron ore for subsequent beneficiation studies in laboratory scale. The experiments were carried out by varying the concentration of H2 SO4 solution and the leaching temperature. The properties of the iron ore was characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM)...

Recommended Citation Qiu, Yang. "Dissolution mechanisms: theoretical and experimental investigations. ABSTRACT Dissolution rate is an important indicator of drug bioavailability. In this work, a mixed-kinetic-controlled dissolution model was developed which encompasses transport control and interface control as limiting cases. This model is mathematically equivalent to two existing mixed-kineti...

a study of the kinetic analysis of total lead from spent car battery ash by hydrochloric acidleaching has been examined. the physico-chemical analysis of the ash powder was carried outby the inductively coupled plasma-mass spectrometry (icp-ms) and x–ray diffraction (xrd).the effects of the acid concentration, temperature and particle size on the rate of battery ashdissolution have been investi...

Biomolecules have significant impacts on the fate and transport of contaminant metals in soils and natural waters. Siderophores, Fe(iii)-binding agents that are exuded by microbes and plants, may form strong complexes with and promote the dissolution of contaminant metal ions, such as Co(iii), U(iv), or Pu(iv). Although aqueous Cr(iii)-siderophore complexes have been recognized in the laborator...

Abstract: In this paper, kinetics of reductive leaching of manganese dioxide ore by ferrous ion in sulfuric acid media has been examined. Experimental results show that increasing temperature from 20 to 60 °C and decreasing ore particle size from −16+20 to −60+100 mesh considerably enhance both the dissolution rate and efficiency. Molar ratios of Fe2+/MnO2 and H2SO4/MnO2 in excess to the st...

The main purpose of this research was to study the mechanism of drug release from solid dispersions of albendazole, giving special emphasis to particle size of the drug in solid dispersions. Solid dispersions were prepared using three different carriers, mixing ratios and methods in an attempt to improve the solubility and dissolution rate of albendazole. The mechanism of enhanced dissolution w...

The kinetics and mechanism controlling dissolution from the (100) cleavage face of potassium bromide single crystals in acetonitrile solutions have been identified using a novel integrated electrochemical/AFM probe and a scanning electrochemical microscope (SECM). With both techniques, dissolution is induced by perturbing the dynamic dissolution/growth equilibrium at the crystal/solution interf...

A study of the kinetic analysis of total lead from spent Car battery ash by hydrochloric acidleaching has been examined. The physico-chemical analysis of the ash powder was carried outby the Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) and X–ray diffraction (XRD).The effects of the acid concentration, temperature and particle size on the rate of battery ashdissolution have been investi...

In situ scanning tunneling microscopy (STM) of the dissolution of a Cu( 1 1 1 ) electrode in aqueous chloride media (HC1 and KCl) was employed to ascertain the mechanism of the reaction at the atomic level. At potentials where there was no dissolution, atomic imaging of the Cu( 1 1 1 ) revealed a ( 6 4 3 x 6d3)R30° structure consisting of a C1 adlattice with a C1-C1 distance of 0.39 f 0.02 nm w...