Equivalent isothermal curves for kinetic analysis of non-stoichiometry

The effect of simultaneously adding P and Cu on the crystallization behavior of hetero-amorphous FeSiB alloy was investigated. Thermal properties and microstructure evolution were studied by means of X-ray diffraction, transmission electron microscopy, differential scanning, and isothermal calorimetric methods. It is found that the addition of P and Cu to the FeSiB alloy changes its crystallization temperature as well as the apparent activation energy for crystallization. The crystallization process is mainly dominated by three-dimensional growth with various nucleation rates for the selected FeSiB(PCu) alloys. The phases formed during crystallization for the different alloys of Fe 84 Si 4 B 12 , Fe 83:3 Si 4 B 12 Cu 0:7 , and Fe 83:3 Si 4 B 8 P 4 Cu 0:7 are similar. The refinement effect of adding P and Cu to the FeSiB alloys is observed. The mean size of -Fe phases decreases from 200 nm to about 20 nm.

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“…Another method is also introduced to calculate the crystallization activation energy using Doyle-Ozawa's method 17) with the following equation:…”

Section: Resultsmentioning

confidence: 99%

Effect of Cu and P on the Crystallization Behavior of Fe-Rich Hetero-Amorphous FeSiB Alloy

Cui

Makino

et al. 2009

Mater. Trans.

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“…Figure 1.b shows the dependence of phase transition temperature on the heating rate for the 6BA/8OBA liquid crystal mixture. The values obtained from Figure 1.b can be used to estimate the associated phase transition activation energy by means of the Ozawa [12], Kissinger [13] and Takhor [14] methods. According to all of the three methods, the activation energy (E A ) changes with temperature, and the value of activation energy can help us to speculate about the energy attributable to a molecular rotational mode.…”

Section: Resultsmentioning

confidence: 99%

Thermal properties of liquid crystal hexylbenzoic acid/octyloxybenzoic acid mixture

Okumuş

2015

AIP Conference Proceedings

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Abstract. The thermal behaviors of binary mixture formed from hydrogen bonded nematic liquid crystals 4-hexylbenzoic acid and 4-(octyloxy)benzoic acid, were investigated by differential scanning calorimetry (DSC). The phase transition temperatures and enthalpies were determined by using calorimetric methods on DSC. The DSC results clearly indicate that the produced liquid crystal mixture displays liquid crystalline properties. The phase transition temperature values increase with increasing heating rate between 5 ºC/min and 20 ºC/min, and the calculated activation energy values show that the reaction arising during the phase transitions of the mixture is regular.

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“…Flynn-Wall-Ozawa method. 22 The integral formula for the calculation of E value is given by the following equation:…”

Section: Model-free Methodsmentioning

confidence: 99%

Influence of alternative cations distribution in AgxLi96-x-LSX on dehydration kinetics and its selective adsorption performance for N2 and O2

2016

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Adsorption characteristics of pure gases N2 and O2 on various silver exchanged low silica X-type (AgxLi96-x-LSX) zeolites were investigated. The equilibrium adsorption isotherms of N2 and O2 were measured at 273 and 298 K. Textual and structural properties of parent and resultant AgxLi96-x-LSX were characterized by XRD, BET surface area, and SEM techniques. Kinetics of their thermal dehydration were studied by exploiting thermogravimetric and differential data (TG-DTG) obtained at three heating rates (5, 10 and 15 K) using two model-free (Kissinger and Flynn-Wall-Ozawa) and one model fitting (Coats-Redfern) methods. Forty one mechanism functions were used to evaluate kinetic triplet (activation energy, frequency factor, and most probable mechanism/model) for different stages of dehydration. Results revealed that the impact of very small content of silver on the adsorption of N2 is pronounced and attributed to weak chemical bonds formed between N2 and Ag+ clusters due to strong adsorption of N2 at low pressure, whereas O2 adsorption is affected to a negligible extent. In addition, the N2/O2 adsorption selectivity shows unexpected low values for Ag87.08Li7.94Na0.98-LSX with higher Ag+ content (91.00 %), which might be due to low crystalline water content as well as Ag+ clusters located at SIII sites. N2 adsorption strongly depends on temperature as higher adsorption occurs at low temperature 273 K as compared to 298 K.

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Equivalent isothermal curves for kinetic analysis of non-stoichiometry

Cited by 137 publications

References 4 publications

Effect of Cu and P on the Crystallization Behavior of Fe-Rich Hetero-Amorphous FeSiB Alloy

Effect of Cu and P on the Crystallization Behavior of Fe-Rich Hetero-Amorphous FeSiB Alloy

Thermal properties of liquid crystal hexylbenzoic acid/octyloxybenzoic acid mixture

Influence of alternative cations distribution in AgxLi96-x-LSX on dehydration kinetics and its selective adsorption performance for N2 and O2

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