Normalized Weibull distribution function for modelling the kinetics of non-isothermal dehydration of equilibrium swollen poly(acrylic acid) hydrogel

Application of the Weibull distribution function for modeling the kinetics of isothermal dehydration of equilibrium swollen poly (acrylic acid) hydrogel

“…This behavior of the density distribution functions of apparent activation energies obtained for the isothermal PAAH dehydration is different from the behavior of density distribution functions obtained for the non-isothermal hydrogel dehydration [21]. In fact, in the case of isothermal dehydration, the density distribution functions of apparent activation energies are shifted to higher values of E a , which is opposite to the case of non-isothermal dehydration (where they are shifted to lower values of E a ) [21].…”

“…In fact, in the case of isothermal dehydration, the density distribution functions of apparent activation energies are shifted to higher values of E a , which is opposite to the case of non-isothermal dehydration (where they are shifted to lower values of E a ) [21]. These results confirm the above statements and enable us to introduce the hypothesis that the dehydration of poly (acrylic acid) hydrogel is governed by two different reaction mechanisms, one under isothermal and the other under non-isothermal conditions.…”

“…The possibility of applying the Weibull distribution function for a kinetic description of the non-isothermal dehydration of equilibrium swollen poly (acrylic acid) hydrogel was investigated in the paper of B. Adnadević et al [21]. It was shown that the dehydration conversion curves at different heating rates can be successfully described by the Weibull distribution function of reacting times, in a wide range of the degree of conversion (a = 0.12-0.93).…”

Nanoindentation characterization of the micro-lamellar arrangement of black coral skeleton

“…The anisotropic behavior of the mechanical properties is associated with mechanical response varying with the stress orientation (Vogel, 2003). This kind of anisotropic behavior of the mechanical properties has also been observed in other chitinous organisms, such as insects and crustaceans (Vincent, 1980(Vincent, , 1990Vincent and Wegst, 2004;Vogel, 2003;Raabe et al, 2005;Sachs et al, 2008), and was attributed to their different components, similar to other composite biomaterials (Koksharov, 1996;Dirikolu et al, 2002;Adnadević et al, 2007;Ersoy et al, 2008). The literature suggests that the outer structural anisotropy in multilayered biological systems serves to direct crack propagation, stress, and energy dissipation to greater depths into underlying more ductile material layers, as well as reduce interfacial stresses and, hence, mitigate delamination.…”

Identification of the effective distribution function for determination of the distributed activation energy models using the maximum likelihood method: Isothermal thermogravimetric data

“…It was first used as a distributed chemical reaction law by Dorko et al 24. Adnađević et al 25 showed that the Weibull distribution function can be used as a “core” function in estimation of activation energy distribution, for the case of complex heterogeneous process.…”