Modelling the dehydration kinetics of four onion varieties in an oven and a solar greenhouse.

The Oven drying kinetics mathematical modelling of four Senegalese onion varieties is carried out in the temperature range from 50 °C to 70 °C. The R2 (dispersion test) and the χ2 (fit test) between the experimental data and the values predicted by the models show that whatever the temperature and the variety, the Verma et al. model is the one that best fits the oven drying kinetics. The R2 average and χ2 average values for the Galmi Violet, Safari, Gandiol F1 and Orient F1 are respectively between 0.9848 to 0.9961 and 0.0010 to 0.006. This best model is validated on the solar greenhouse drying kinetics at variable temperatures during the drying process. The Drying Characteristic Curves (DCCs) have identical patterns for the four onion varieties and are described with third order polynomials in the reduced moisture content range from 0.1 to 0.7. The Galmi Violet, with the slowest drying rate, is the limiting variety, followed by the Safari, Gandiol F1 and Orient F1. Furthermore, the critical and equilibrium reduced moisture content deduced from the DCCs are respectively between 0.55 to 0.70 and 0.05 to 0.15.

Mathematical Model of the Dynamics of Fish, Waterbirds and Tourists in the Djoudj National Park, Senegal.

In the present paper, we propose and analyze a harvested predator-prey model that incorporates the dynamics of tourists in the Djoudj National Park of Birds, Senegal. The model describes the impact of migration of waterbirds and seasonal fishing on the global coexistence of species in the site of the Djoudj. By the Mahwin continuation theorem of coincidence degree theory, we investigate the existence of a positive periodic solution. The global asymptotic stability is discussed by constructing a suitable Lyapunov functional. Some computational results are also addressed.

Relationship between orthodontic anomalies and masticatory function in adults.

INTRODUCTION: Normal mastication requires the coordinated action of many elements, including teeth, salivary glands, tongue, and masticatory muscles. Dysfunction in any of these areas can result in impaired masticatory function. Few studies dealt with the influence of occlusal conditions on the masticatory function. Our aim in this study was to examine to what extent masticatory function is impaired in subjects with occlusal anomalies. METHODS: Masticatory function was studied in 102 untreated adults. They were observed while chewing a standard test food for 20, 30, and 40 chewing strokes. Orthodontic condition was assessed with the index of complexity, outcome, and need (ICON). From the masticatory test, 3 variables were obtained: median particle size (MPS), broadness of the particle distribution (BPD), and masticatory frequency (F). RESULTS: MPS was significantly larger in subjects with ICON scores >43 (definite-need subsample) than in subjects with ICON scores < or =43 (no-need subsample) when the masticatory test was performed with 20, 30, or 40 cycles (P =.05, .03, and .01, respectively). BPD also followed the same trend, but the differences were not significant (P = .33, .16, .14 for 20, 30, and 40 cycles, respectively). Also, the differences in F between the 2 subsamples were not significant (P = .26, .45, .37). CONCLUSIONS: The results suggest that, in addition to esthetic considerations, improving a patient's chewing function by improving occlusal relationships could be an indication for orthodontic treatment.