Post-harvest treatment of algerian broad beans using two different solar drying methods

[EN] This work was carried up in the objective to valorize the broad beans, largely harvested in Algeria, by solar drying means. In the present research paper, an experimental study was conducted on solar drying of broad beans by two different methods. Experimental trials were performed on a direct and an indirect laboratory scale solar dryers at Ouargla university in the southern of Algeria. Selected samples were dried at 50°C, 55°C, 60°C and 65°C. In both two applied cases, drying curves were obtained and compared. Among twelve consulted drying models the Page model was correlated with satisfaction to describe the solar drying of broad beans using a non linear regression analysis method. Operating and thermal performances of the two used drying systems were checked by the energy effeceincy and economic calculation. Obtained results showed that the direct solar drying ensures good preservation of the final product with a drying time of 5 hours.Chouicha, S.; Boubekri, A.; Berbeuh, M.; Mennouche, D.; Frihi, I.; Rzezgua, A. (2018). Post-harvest treatment of algerian broad beans using two different solar drying methods. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 1365-1372. https://doi.org/10.4995/IDS2018.2018.7858OCS1365137

Non-isothermal crystallization kinetics of polyamide 66/glass fibers/carbon black composites

cited By 7International audienceThe non-isothermal crystallization of the polyamide 66 (PA66) reinforced with 15 mass% glass fibers and/or 0.4 mass% carbon black has been the object of a thermal analysis by differential scanning calorimetry with various cooling rates ranging from 2 to 25 °C min−1. The modified Avrami’s equation, Ozawa’s theory and Mo’s method were applied to study the non-isothermal crystallization kinetics of neat PA66 and the PA66 composites. The activation energies of non-isothermal crystallization were calculated by Kissinger method. The results showed that the Mo’s method can successfully account for the overall non-isothermal crystallization kinetics for neat PA66 and PA66 composites. The modified Avrami’s method and Ozawa’s approach as well did not apply satisfactorily. It was also revealed that GF and CB could accelerate the crystallization rates of PA66. The combined effect of GF and CB was shown to be stronger than that of GF only in spite of rather low CB content. © 2016, Akadémiai Kiadó, Budapest, Hungary

Mixed percolating network and mechanical properties of polypropylene/talc composites

cited By 7International audienc

Cracking behavior of carbon black filled elastomers

cited By 1International audienceThe study of crack propagation in rubber has a very high economic significance but is still not well understood. For this purpose the main objective of this work is to study the fracture behavior of two types of rubber: the NR, which crystallizes under stress and the noncrystallizing SBR. To study the cracking behavior of materials we have made tests of cracking follow-up. The mode of crack propagation has been studied in terms of fillers ratio and traction speed. The unfilled SBR and NR showed simple lateral propagation independently of the test speed, whereas the mode of cracking of filled materials was very influenced by the parameters mentioned previously. The filled SBR can present important deviations of the crack when the fillers ratio is sufficiently high; this deviation is even more pronounced when the speed increases. On the other hand, the natural rubber which crystallizes under stress showed particular mode of propagation characterized by the appearance of longitudinal cracks. This mode of cracking is much more important at low speeds than at the high speeds. It is proposed that the fillers increase the breaking strength of a noncrystallizing material and allows that the crack takes a deviated way if the fillers ratio is sufficiently high. But if it is a material which crystallize like the NR, crystallization and fillers will act simultaneously and the material will be much more resistant which gives rise to a particular mechanism which is the appearance of the longitudinal cracks before the catastrophic rupture. © 2010 World Scientific Publishing Company

Optimization of the crystallinity of polypropylene/submicronic-talc composites: The role of filler ratio and cooling rate

cited By 4International audienceMicronic and submicronic mineral fillers recently appeared as efficient reinforcing agents for polyolefins in addition to the benefit of bypassing the exfoliation/dispersion problem encountered in the case of incorporation of nanoscopic fillers such as clay. Submicronic-talc, designated as μ-talc, belongs to this kind of new fillers. This work was aimed at searching to optimize the crystallinity ratio of isotactic polypropylene in the presence of μ-talc in relation to the filler ratio of the composites and the cooling rate from the melt. In order to highlight the efficiency of the μ-talc on the crystallization of polypropylene comparison has been made with PP composites containing conventional talc particles. The study has been carried out on samples having μ-talc weight fractions covering the range 3–30%. In the context of optimizing the crystallinity ratio of the polypropylene matrix in the composites, calorimetric experiments have been planned using a full factorial design. The results were statistically processed by analysis of the variance via mathematical models for predicting the crystallinity ratio in relation to the cooling rate and the filler ratio. Contour graphs have been plotted to determine the effect of each parameter on crystallinity. The cooling rate proved to have a significantly stronger influence on crystallinity than the type and content of filler. © BME-PT

Non-isothermal crystallization kinetics and nucleation behavior of isotactic polypropylene composites with micro-talc

cited By 1The non-isothermal crystallization (NIC) of isotactic polypropylene (iPP) and its composites with submicronic talc particles (μ-talc) was investigated by differential scanning calorimetry. The modeling of the NIC kinetics of the iPP matrix was performed using Jeziorny-modified Avrami’s model, Ozawa’s and Mo’s theoretical approaches. The Jeziorny’s and Ozawa’s theories allowed us to confirm that the μ-talc filler particles significantly promote the NIC kinetics of the iPP matrix which noticeably manifests itself via a change in the nucleation mechanism. However, Mo’s model proved to be the more relevant model to account for the NIC of the present materials. In parallel, the activation energy and nucleation activity of NIC were calculated by Kissinger’s and Dobreva’s methods, respectively. Both approaches reveal that a maximum nucleation activity of μ-talc takes place for 20% filler content. This finding is discussed in relation to the μ-talc content thresholds of mechanical percolation and crystallinity saturation that were reported in previous studies for these composites, about 10 and 30% μ-talc, respectively. An endeavor of physical explanation for these phenomena is put forward. © 2019, Akadémiai Kiadó, Budapest, Hungary

Crystallization of glass-fiber-reinforced polyamide 66 composites: Influence of glass-fiber content and cooling rate

International audienc