In the present work, the in¯uence of the nucleation time-lag on the non-isothermal glass crystallization is discussed. Di€erential thermal analysis (DTA) results of an iron-rich glass nucleated by Cr 2 O 3 were obtained at di€erent heating rates. The activation energy of crystallization, E c , and the Avrami parameter, m, estimated by Kissinger's and Ozawa's equations were shown to be dependent...

The kinetics of molybdenite oxidation was studied by non-isothermal TGA-DTA with heating rate 5 ºC.min-1.The model-fitting kinetic approach applied to TGA data .The Coats-Redfern method used for model fitting. The popular model-fitting gives excellent fit for non-isothermal data in chemically controlled regime. The apparent activation energy was determined to be about 34.2 kcalmo...

The crystallization of undercooled Pd43Ni10Cu27P20 melts is studied under isothermal conditions and at constant heating and cooling rates. Investigations are carried out by fluxing the melt with B2O3 and without any fluxing material. The isothermal experiments allow us to determine the complete time–temperature-transformation diagram with a minimum crystallization time of about 200 s for the fl...

Dimerization process is essential for producing copolymers. The features of dimerization process like thermal-oxidative degradation should be well known to reach maximum efficiency and a superior reactor design. Also, the degradation mechanism of biodegradable polymers is important during sterilization processes. Thermal-oxidative degradation of PGA, PLLA, and their binary copolymers was invest...

Thermal behavior of plastic materials can be improved by knowing thermal degradation kinetics for the optimal design and operation of pyrolysis process. In the present study, thermogravimetric analysis has been used for the non-isothermal kinetic study of waste high-density polyethylene pyrolysis under nitrogen atmosphere at different heating rates 10, 20 and 40 °C/min. The kinetic parameters, ...

Non-isothermal conditions during flight cycles have long led to the requirement for thermo-mechanical fatigue (TMF) evaluation of aerospace materials. However, the increased temperatures within the gas turbine engine have meant that the requirements for TMF testing now extend to disc alloys along with blade materials. As such, fatigue crack growth rates are required to be evaluated under non-is...

Context. In isothermal disks the migration of protoplanets is directed inward. For small planetary masses the standard type I migration rates are so fast that this may result in an unrealistic loss of planets into the stars. Aims. We investigate the planet-disk interaction in non-isothermal disks and analyze the magnitude and direction of migration for an extended range of planet masses. Method...

A dynamic computational model developed within the context of the classical theory of phase evolution is applied to the W–C system to simulate the kinetics of graphite nucleation during non-equilibrium peritectic melting of WC. The kinetic variables used in the model are obtained directly from the free energy formulations that characterize the stable and metastable equilibria between WC, liquid...

Non-isothermal crystallization kinetics of polydioxanone (PDO), a polymer with well-established applications as bioabsorbable monofilar suture, was investigated by Avrami, Mo, and isoconversional methodologies. Results showed Avrami exponents appearing in a relatively narrow range (i.e., between 3.76 and 2.77), which suggested a three-dimensional spherulitic growth and instantaneous nucleation ...

Water exists in at least two families of glassy states, broadly categorized as the low-density (LDA) and high-density amorphous ice (HDA). Remarkably, LDA and HDA can be reversibly interconverted via appropriate thermodynamic paths, such as isothermal compression and isobaric heating, exhibiting first-order-like phase transitions. We perform out-of-equilibrium molecular dynamics simulations of ...