Selection of a Relevant Mathematical Model for Drying of Tomato Slices Using Solar Dryer

In this research, solar drying of a thin layer of tomato slices was evaluated. The experiments were carried out at the air velocities of 0.5 and 1.0 m s-1 and thicknesses of 3, 5 and 7 mm. In order to find the most suitable form of thin layer drying model, nine different mathematical drying models were fitted to the experimental data to determine the pertinent coefficients of each model. The goodness of the fit was determined by calculating and comparing the values of the correlation coefficient (R^2 ) Root mean square error (RMSE) and chi-square (χ^2) for all models. The Page model with R^2=0.9974 ,χ^2=0.01351 , RMSE=0.002 showed the best fit

Investigation of avalanche time and carr’s index of poultry litter powder as flowability indices

The world’s dependence on chemical fertilizer as the primary source for enriching agricultural fields is continually increasing that cause nature pollution. This has led researchers to aggressively investigate renewable fertilizer resources, biomass, to produce organic crops and reduced wastage. Poultry litter is a bulk solid and biomass feed stocks. Flow behavior of bulk solid is a critical factor in designing and developing suitable equipments (e.g. pelletizing machine). The bulk density, tap density, Carr’s index and powder avalanche time technique were applied to evaluate the flow properties of poultry litter. The experiments were carried out at moisture content (10, 20 and 30% w.b.), particle size (0.3, 0.6 and 1.18 mm) for the bulk and tap densities as well as Carr’s index. In addition to the moisture content (10, 20 and 30 %w.b.) and particle size (0.3, 0.6 and 1.18 mm) the rotational speed of drum (0.5, 1 and1.5 rpm) were also investigated for the avalanche time. The results showed that with increasing moisture content Carr’s index increased significantly (P<0.01) in the ranges of 16.2% to 18.5% and with increasing particle size the Carr’s index decreased from 20.35% to 14.78%. The litter powder avalanche time (AT) increased significantly (P<0.01) with increasing moisture content and decreasing rotational speed and particle size. The bulk and tap densities of the litter powder was decreased with increasing moisture content and increasing the particle size. The bulk and tap densities of the driest and finest poultry litter sample were higher than other ones