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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.

The phase transitions in LiNH4SO4 (LAS) were studied below and above room temperature by means of several techniques: modulated differential scanning calorimetry (MDSC), capacitance and ac thermal measurements. Our results show four distinct phases transitions at 460, 285, 225 and 28 K on cooling runs. The phase transitions at 460 and 285 K are of first order. The 225 K phase transitions is reported for the first time. The capacitance results show a strong hysteretic behavior in the 225 K transition on successive heating and cooling cycles attributed to the field effect on the polar ordering.

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