Modeling and Simulation of Temperature and Relative Humidity Inside a Growth Chamber

Modeling and simulation of internal variables such as temperature and relative humidity are relevant for designing future climate control systems. In this paper, a mathematical model is proposed to predict the internal variables temperature and relative humidity (RH) of a growth chamber (GCH). Both variables are incorporated in a set of first-order differential equations, considering an energy-mass balance. The results of the model are compared and assessed in terms of the coefficients of determination (R2) and the root mean squared error (RMSE). The R2 and RMSE computed were R2 = 0.96, R2 = 0.94, RMSE = 0.98 C, and RMSE = 1.08 C, respectively, for the temperature during two consecutive weeks; and R2 = 0.83, R2 = 0.81, RMSE = 5.45%RH, and RMSE = 5.48%RH, respectively, for the relative humidity during the same period. Thanks to the passive systems used to control internal conditions, the growth chamber gives average differences between inside and outside of +0.34 C for temperature, and +15.7%RH for humidity without any climate control system. Operating, the GCH proposed in this paper produces 3.5 kg of wet hydroponic green forage (HGF) for each kilogram of seed (corn or barley) harvested on average

Morphological Analysis of UO2_2 Powder using a Dead Leaves Model

In the present work, we propose a set of methods for a Morphological analysis of powder media. To evaluate our methods, we apply them to $\rm UO_2$ powder. These methods are based on a Dead Leaves Model which simulates a masking process. Generally speaking, our methods require no image segmentation. We found, that it is preferable to eliminate the segmentation approach for complex structures and to work directly on the grey level images. We compare these new algorithms with the traditional method of establishing the size distribution by openings, to show their relative performance.Dans cette étude, nous proposons un ensemble de méthodes pour l'analyse morphologique de milieux pulvérulents. Ces méthodes sont évaluées à partir d'applications à des poudres d'UO2. Elles sont basées sur le modèle des feuilles mortes, qui simule un processus de masquage, et ne nécessitent pas de segmentation d'images. Nous avons constaté qu'il est préférable d'éliminer l'approche de type segmentation pour les structures complexes, et d'opérer directement sur les images à niveaux de gris. Ces nouveaux algorithmes sont comparés aux méthodes traditionnelles pour mesurer une granulométrie par ouvertures