|
|
|
|
|
| Zeymer,Juliana S.; Corrêa,Paulo C.; Oliveira,Gabriel H. H. de; Baptestini,Fernanda M.; Faria,Igor L.. |
| ABSTRACT This study aimed to determine the thermodynamic properties of sorption processes (desorption and adsorption) of rice in the husk, cv. Urucuia. A static-gravimetric method was used to reach equilibrium moisture content at different temperatures (10, 20, 30, 40, and 50 °C ± 1°C) and relative humidity levels (10, 30, 50, 70, and 90 % ± 2%). A decrease in moisture content led to an increment of the integral isosteric heat of sorption, indicating a higher demand for energy to remove moisture from the product. Differential entropy of sorption decreased along with a moisture content increment, with higher values for desorption. This indicates a higher mobility of water molecules during desorption if compared to adsorption. Gibbs free energy decreased... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Equilibrium moisture content; Integral isosteric heat of sorption; Differential entropy; Gibbs free energy; Enthalpy-entropy compensation theory. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162018000300369 |
| |
|
| |
|
|
| Zeymer,Juliana S.; Corrêa,Paulo C.; Oliveira,Gabriel H. H.; Baptestini,Fernanda M.; Campos,Renata C.. |
| ABSTRACT Knowledge on sorption isotherms is important for predicting drying and storage processes of a product. A sorption isotherm can be generated from two processes: desorption and adsorption. The lag between these two curves is called hysteresis. Static method was used to obtain the equilibrium moisture content of paddy rice grains, in different temperature (10, 20, 30, 40 and 50 ± 1°C) and relative humidity (between 11 and 76% ± 2%) conditions. Equilibrium moisture content data were correlated with eight mathematical models and. The Chung Pfost model had the best fit to the experimental data. Desorption and adsorption isotherms, represented by the Chung Pfost model, showed a sigmoidal shape, characteristic of type II curve. Equilibrium moisture... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Adsorption; Desorption; Hygroscopic equilibrium; Relative humidity; Temperature. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162019000400524 |
| |
|
|
| Zeymer,Juliana S.; Corrêa,Paulo C.; Oliveira,Gabriel H. H. de; Baptestini,Fernanda M.; Freitas,Rita C. P.. |
| ABSTRACT Lactuca sativa seeds are highly sensitive to climate conditions; thus, they should be stored securely to maintain their qualitative and quantitative characteristics. Studies on hygroscopicity aim to decrease possible changes in agricultural products under specific environmental conditions. Accordingly, this study aims to develop an appropriate mathematical model to represent the desorption isotherms of Lactuca sativa seeds. The hygroscopic equilibrium was achieved using a static-gravimetric method at temperatures of 10, 20, 30, 40 and 50 °C and water activity in the range 0.11-0.96. Six mathematical models were fitted to the experimental data of the equilibrium moisture content of Lactuca sativa seeds. The best model was chosen based on the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Mathematical modeling; Hygroscopic equilibrium; Relative humidity; Temperature. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017000800568 |
| |
|
|
|
