the kinetics of zn sorption by ten calcareous soils of iran were measured and fitted to several equations (zero-, first-, second-, third-order, parabolic diffusion, simple elovich, and exponential equations). two initial concentrations of zinc i.e. 20 and 80 mg zn l-1 were used and observations were carried out for 100 hours. the time required to reach the near equilibrium state was about 24 ho...

ABSTRACT. Rhodamine B (RhB) is one of the prominent dyes discovered to be carcinogenic and mutagenic substance present in ecosystem. Alteration characteristics TiO2 through modification with clay influences behavior some organic molecules at its surface, thus photocatalytic properties. This study investigates degradation RhB using TiO2-activated kaolinite composite (TiO2-AKC). TiO2-AKC was prep...

Modification of the surface layer of polyurethane with plasma-immersion ion implantation (PIII) and studying its physical and chemical changes have been discussed in this paper. The goal of the research was to obtain carbonized layer allowing creating biocompatible polyurethane implants. The experiments of PIII treatment in various modes were performed. The investigation of the modified surface...

A moving, solidifying interface that grows by the instantaneous adsorption of a diffusing solute is described by the classic one-sided “Stefan problem” [15, 19]. More generally, the behavior of precipitate growth can depend on both surface kinetics and bulk drift of the depositing species. We generalize the Stefan problem and its interface boundary condition to explicitly account for both surfa...

A moving, solidifying interface that grows by the instantaneous adsorption of a diffusing solute can be described by equations analogous to those of the classical one-sided Stefan problem for solidification. However, the behavior of precipitate growth by material deposition can depend on both surface kinetics and bulk drift of the depositing species. We generalize the Stefan problem and its int...

Dissolution kinetics of the (110) face of salicylic acid in aqueous solution is determined by hopping intermittent contact scanning electrochemical microscopy (HIC-SECM) using a 2.5 μm diameter platinum ultramicroelectrode (UME). The method operates by translating the probe UME towards the surface at a series of positions across the crystal and inducing dissolutio n via the reduction of protons...