Modeling of drying kinetic of pretreated sour cherry.
The effects of pretreatment solution (dipping in boiling water, salty boiling water, ethil oleat) were studied on drying kinetic of sour cherry. The thin-layer drying of sour cherries were carried out at three air temperatures of 50, 60 and 70°C and airflow velocity of 1 m/s. The experimental data were fitted to several thin-layer drying models such as Newton, Henderson and Pabis, Page, Logarithmic, Approximate Diffusion, Two-term exponential, and Midilli et al.. Three statistical tools coefficient of determination (R2), reduced chi-square (x2) and root means square error (RMSE) were used to quantify the goodness of fit. According to the results, drying time of sour cherry samples dipped in salty boiling water solution was shorter than the pretreated samples and control treatments. Besids, The Midilli et al. and Logarithmic models were found to be most suitable in describing the drying characteristics of sour cherry respectively. The effective moisture diffusivity of sour cherries based on the analytical solution of Fick’s second law ranged from 2.07×10-11 to 2.33×10-10 m2/s. Using of pretreated solutions caused to decreasing activation energy in sour cherry drying process. Activation energy values varied from 23.74 to 83.05 kJ/mol.
Modeling for Drying of Thin Layer of Native Cassava Starch in Tray Dryer
Purpose: The drying of a thin layer of native cassava starch in a tray dryer was modeled to establish an equation for predicting the drying behavior under given conditions. Methods: Drying tests were performed using samples of native cassava starch over a temperature range of 40-60°C. We investigated the variation in the drying time, dynamic equilibrium moisture content, drying rate period, critical moisture content, and effective diffusivity of the starch with temperature. The starch diffusion coefficient and drying activation energy were determined. A modification of the model developed by Hii et al. was devised and tested alongside fourteen other models. Results: For starch with an initial moisture content of 82% (db), the drying time and dynamic equilibrium moisture content decreased as the temperature increased. The constant drying rate phase preceded the falling rate phase between 40-55°C. Drying at 60°C occurred only in the falling rate phase. The critical moisture content was observed in the 40-55°C range and increased with the temperature. The effective diffusivity of the starch increased as the drying temperature increased from 40 to 60°C. The modified Hii et al. model produced randomized residual plots, the highest R 2 , and the lowest standard error of estimates. Conclusions: Drying time decreased linearly with an increase in the temperature, while the decrease in the moisture content was linear between 40-55°C. The constant drying rate phase occurred without any period of induction over a temperature range of 40-55°C prior to the falling rate period, while drying at 60°C took place only in the falling rate phase. The effective diffusivity had an Arrhenius relationship with the temperature. The modified Hii et al. model proved to be optimum for predicting the drying behavior of the starch in the tray dryer. Modified Hii et al.
Daily weather variables and affective disorder admissions to psychiatric hospitals
Numerous studies have reported that admission rates in patients with affective disorders are subject to seasonal variation. Notwithstanding, there has been limited evaluation of the degree to which changeable daily meteorological patterns influence affective disorder admission rates. A handful of small studies have alluded to a potential link between psychiatric admission rates and meteorological variables such as environmental temperature (heat waves in particular), wind direction and sunshine. We used the Kruskal-Wallis test, ARIMA and time-series regression analyses to examine whether daily meteorological variables—namely wind speed and direction, barometric pressure, rainfall, hours of sunshine, sunlight radiation and temperature—influence admission rates for mania and depression across 12 regions in Ireland over a 31-year period. Although we found some very weak but interesting trends for barometric pressure in relation to mania admissions, daily meteorological patterns did not appear to affect hospital admissions overall for mania or depression. Our results do not support the small number of papers to date that suggest a link between daily meteorological variables and affective disorder admissions. Further study is needed.