In the present study, a differential model of the plug flow fluidized bed dryer for shelled corn was presented. The model was developed by using the mass balance of moisture content inside a control volume of the bed based on the axial dispersion phenomenon and an appropriate drying rate equation. The differential equation resulted from the model was solved numerically by finite difference method. To validate the model, several experiments for shelled corn drying in a plug flow fluidized bed dryer under steady state conditions were performed at three inlet dry solid mass flow rates (245, 420 and 565 g/min), six drying air temperatures (50, 60, 70, 80, 90 and 100 °C) and two weir heights (0.025 and 0.05 m). The model was capable to predict correctly the moisture content of the grains at any locations along the dryer length. Based on the simulation results, the solid moisture content decreased discontinuously at the solid inlet boundary of the bed and then decreased continuously along the dryer length. The simulation results were also analyzed to investigate the effects of inlet gas temperature, weir height and inlet dry solid mass flow rate on the solid moisture content. The solid moisture content decreased by increasing inlet gas temperature and weir height, whereas it increased by increasing the inlet dry solid mass flow rate.

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This paper introduces an alternative method to model the tire dynamic parameters of an agricultural vehicle from experimental data sets without the use of conventional test equipment. A Global Positioning System implementing a Real Time Kinematic scheme (RTK-GPS) and an Inertial Measurement Unit (IMU) are used to estimate the vehicle's body sideslip angle and to establish the relation between the tire's lateral forces and slip angles for different soil conditions; in terms of soil moisture content and cone index. To validate the method introduced in this paper, the results obtained from the experimental data sets were compared with an empirical modeling method; which uses a particular form of the relationship between lateral force, normal force and slip angle expressed as an exponential function. Results show that the method introduced in this paper can give a more accurate description of the relation between the tire's lateral forces and slip angles. This knowledge can be applied to improve automatic steering controller systems.

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Changes in the enzymatic and physicochemical properties of sweet potatoes processed by a combination of pre-heating and high-temperature blanching were investigated. First, the characteristics of the inactivation of peroxidase and pectin methylesterase were analyzed, showing that 112.7 and 119.6 kJ mol⁻¹ of activation energy were required for inactivation, respectively. The result also suggested that a temperature of over 94 °C was better to inactivate peroxidase effectively. Second, the optimum conditions for pre-heating treatment were selected through the consideration of quality attributes. Pre-heating at 60 °C and 65 °C produced a stronger effect of enhancing firmness. However, some adverse effects on nutrients and appearance were noted at temperatures over 65 °C. Eventually, pre-heating at 60 °C for 40 min was selected as the best condition for sweet potato slices.

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In this paper, an artificial neural network (ANN) modeling is utilized to predict kinetics of essential oils extraction from tarragon (Artemisia dracunculus L.) using Ultrasound pre-treatment with Clevenger. A three-layer perceptron artificial neural network was created to predict the extract model with an error back-propagation algorithm. To design the ANN model, ultrasound power, sonication time, extraction time and their interactions were considered as input vectors while the extraction yield of essential oils was considered the model output. The performance of the network was optimized by varying the number of nodes in the hidden layer to achieve the best ANN architecture for output prediction. The performance of different ANN architectures was obtained as error (mean squared errors: MSE) and goodness of fit (determination coefficient: R²) parameters. The results showed that the best prediction performance belonged to 3-7-1 ANN architecture (0.0008 normalized MSE and 0.99 R²) which means that it is possible to predict the extraction yield of essential oils with an acceptable error having the three input parameters. The main extracted compounds by two methods at different conditions were estragole (76.6–83.0%), (Z)-β-ocimen (5.7–8.7%), (E)-β-ocimen (5.2–7.9%).

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The air-seeder became a solution, when the working width increasing of conventional mechanical seed drills having the storage hopper across the all working width had reached its limits. The single storage hopper of a modern air-seeder can supply the working widths up to 24 m, over many operating hours. However, it should be noted that to ensure the accurate loading of metered material into the air delivery system, we are faced by the problem of pressure difference between the storage hopper and the air stream. Most modern air-seeders are equipped with a Venturi-injector or a pressurized hopper (called also: pressurized tank). Even if both loading systems are largely used, there are no theoretical and scientific justifications in favour of these systems, since few evaluation reports based only on practical observations are available. Thus, this paper deals with a study on the influence of an air-stream loading system type on the total energy consumption and seeds-metering precision. Moreover, this paper proposes an explanatory model of the functioning conditions of each system. Experimental demonstrations show that pressurized systems are more convenient from an energetic efficiency point of view.

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The absorption coefficient and reduced scattering coefficient of tofu were determined at 633 nm by spatially resolved diffuse reflectance at different soymilk coagulation temperatures. Added absorber method, in which ink is added to a sub-sample, was used to determine the two optical coefficients separately. The two coefficients were compared with viscosity. The reduced scattering coefficient increased with coagulation temperature, while the absorption coefficient showed no significant change. Since the order of the absorption coefficient was much smaller than that of the reduced scattering coefficient, scattering was more dominant than absorption in tofu. Also since the correlation between the reduced scattering coefficient and viscosity was observed, it can be used to evaluate the quality of tofu.

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