the purpose of this study is comparison of manganese absorption capacity by natural and modified zeolite. for this purpose used by from semnan mines zeolite with mean particle diameter of 360 micrometer. for modified zeolite, 5 g amount of natural zeolite with 100 ml of 1 m sodium chloride solution mixed and maintained at 24 hours in room temperature. for measure specific surface of absorbents,...

Electrocoagulation (EC) was used for the removal of anthraquinone dye, Alizarin Red S (ARS) from aqueous solution. The process was carried out in a batch electrochemical cell with Al electrodes in a monopolar connection. The effects of some important parameters such as current density, pH, temperature and initial dye concentration, on the process were investigated. Equilibrium was attained afte...

Isothermal melt crystallization kinetics of PVDF was investigated by differential scanning calorimetry. Thin PVDF film has been fabricated by the solvent casting technique using dimethylformamide (DMF). Then, the samples were melted and subsequently crystallized in the range of the crystallization temperature (Tc) between 138 and 145 °C. The crystallization kinetics was derived from Avrami equa...

It has been shown experimentally by many researchers that cooling rate and crystallization temperature affect the rate of crystal formation. In this study, crystallization kinetics of coconut oil was measured by monitoring the solid fraction of the oil using pulsed Nuclear Magnetic Resonance (pNMR). Four levels of cooling rate and crytallization temperature were studied. Parameters of crystalli...

Different kinetic models like the Avrami, Tobin and Urbanovici-Segal models have been applied for determining the isothermal crystallization kinetics of virgin poly(ethylene terephthalate) (PET) and PET/poly(methyl methacrylate) (PMMA) blends. The different compositions investigated were PET90/PMMA10, PET75/PMMA25 and PET50/PMMA50 [wt/wt%]. The experimental data was fitted using Solver, a non-l...

The homogeneous nucleation and growth in a simplest two-dimensional phase field model is numerically studied using the cell dynamics method. The whole process from nucleation to growth is simulated and is shown to follow closely the Kolmogorov-Johnson-Mehl-Avrami (KJMA) scenario of phase transformation. Specifically the time evolution of the volume fraction of new stable phase is found to follo...

It is quite frequent for a number of solid–state transformations to occur concurrently, starting from the same parent phase. The transformations may occur at different rates, but the resulting competition for space or for the partitioning of driving force between the precipitating phases can be seminal to the development of many microstructures found in commercial alloys. This paper reviews the...

If certain preconditions are met, the Johnson-Mehl-Avrami-Kolmogorov (JMAK) kinetic equation is exactly accurate for nucleation and growth reactions with linear growth and is, at least, a good approximation for nucleation and growth reactions with parabolic growth. These preconditions include randomly distributed product phases, isotropic growth and constant equilibrium state. Mechanisms causin...

The reaction pathway and kinetics of a-CuInSe2 formation from a glass/In2Se3/CuSe polycrystalline bilayer precursor film were investigated using time-resolved, in situ high-temperature X-ray diffraction. Bilayer glass/In2Se3/CuSe precursor films were deposited on thin glass substrates in a migration enhanced molecular beam epitaxial deposition system. These films were then temperature ramp anne...

The non-isothermal transformation rate curves of metallic glasses are analyzed with the Master Curve method grounded in the Kolmogorov-Johnson-Mehl-Avrami theory. The method is applied to the study of two different metallic glasses determining the activation energy of the transformation and the experimental kinetic function that is analyzed using Avrami kinetics. The analysis of the crystalliza...