A four year study to determine the optimal harvesting period for Tunisian Chemlali olives

Due to the importance of the stage of maturity on several olive pomological parameters and oil quality indices, and to the interest that Tunisian olive oil production has recently received, the optimal harvesting period for the main Tunisian olive cultivar, Chemlali, was assessed. For the first time, a four‐season crops study, carried out in three representative geographical areas, was focused on both olive fruit pomological parameters and oil chemical composition at different stages of maturity. The stage of maturity was the factor showing the highest influence on the major part of these parameters, followed by the crop year. To guarantee a reasonable fat content and a good chemical quality of oil, in particular a harmonious acidic composition, acceptable UV absorbance, and a content high of antioxidants, unsaponifiable matter and sterols, the optimal harvesting period for Chemlali olives would appears to be between the end of November to the middle of December, which corresponds to a maturity index between 2.5 and 3.5.     

Multi‐expression programming based model for prediction of formation enthalpies of nitro‐energetic materials

There has been considerable interest in predicting the properties of nitro‐energetic materials to improve their performance. Not to mention insightful physical knowledge, computational‐aided molecular studies can expedite the synthesis of novel energetic materials through cost reduction labours and risky experimental tests. In this paper, quantitative structure–property relationship based on multi‐expression programming employed to correlate the formation enthalpies of frequently used nitro‐energetic materials with their molecular properties. The simple yet accurate obtained model is able to correlate the formation enthalpies of nitro‐energetic materials to their molecular structure with the accuracy comparable to experimental precision.