Thermal Characterization and Lifetime Estimation of the Humus Lombricospt

Abstract

Through this study, the humus produced in the breeding place of Universidad Autonoma de Occidente was thermally characterized. The humus was submitted to a heating program controlled by the Differential Scanning Calorimetry (DSC) technique to characterize the type of transition, Thermogravimetry (TGA) to study the equilibrium of phasesand Mass Spectrometry (MS) coupled to TGA to identify detached elements in a temperature range. The temperature range used in this study was 30˚C < T < 600˚C. The energy required for the water desorption in the humus has been found in this study. The humus showed a quick desorption between 30˚C ≤ T Desorption ≤ 110˚C at a heating rate of 10˚C/min and presented decomposition around 250˚C. Moreover, the kinetics of the desorption of the humus was studied to obtain the activation energy three TGA measures for three different heating rates. The average activation energy was about 26 kJ/Mol. This result was carried out to obtain an estimation of the desorption time of water in the range from room temperature to the decomposition temperature around 350˚C.

Decomposition kinetics and lifetime estimation of natural fiber reinforced composites: Influence of plasma treatment and fiber type

“…In order to estimate the useful life of all studied materials, it is necessary to define which decomposition degree is considered for material failure. The most common is to consider the failure as soon as the decomposition begins, so it is generally considered at 5% of decomposition degree [29]. Mass spectrometry is also useful to corroborate the above affirmation.…”

“…With known E a and by applying Toop equation (25), by equation (2) it is possible to estimate lifetime of each material as a function of temperature [29]where β is the heating rate, R is the gas constant, E a is the activation energy calculated for one particular degradation degree (obtained from MFK), T f is the chosen temperature to estimate lifetime, and t f is the estimated time until material failure. P ( X f ) is a function, which is controlled by E a / RT c values, where T c is the temperature at the decomposition degree, which is considered as a material failure, according to the Toop tabulation [25].…”

“…With known E a and by applying Toop equation (25), by equation ( 2) it is possible to estimate lifetime of each material as a function of temperature [29]…”