Sweet sorghum has become a promising alternative feedstock for biofuel production because it can be grown under reduced inputs, responds to stress more efficiently than traditional crops, and has large biomass production potential. A three-year field study was conducted to evaluate three cultivars of sweet sorghum as bioenergy crops in the Southeast United States (Fort Valley, Georgia): Dale, M81 E and Theis. Parameters evaluated were: plant density, stalk height, and diameter, number of nodes, biomass yield, juice yield, °Bx, sugar production, and theoretical ethanol yields. Yields were measured at 85, 99, and 113 days after planting. Plant fresh weight was the highest for Theis (1096 g) and the lowest for Dale (896 g). M81 E reported the highest stalk dry weight (27 Mg ha−1) and Theis reported the lowest (21 Mg ha−1). Theis ranked the highest °Bx (14.9), whereas M81 E was the lowest (13.2). Juice yield was the greatest for M81 E (10915 L ha−1) and the lowest for Dale (6724 L ha−1). Theoretical conservative sugar yield was the greatest for Theis (13 Mg ha−1) and the lowest for Dale (9 Mg ha−1). Theoretical ethanol yield was the greatest for Theis (7619 L ha−1) and the lowest for Dale (5077 L ha−1).

Abstract. The bioactivity of Sericea lespedeza (SL) condensed tannins, including suppression of gastrointestinal nematodes, has contributed to a surge in interest of use of this plant in livestock production systems worldwide. Physical and thermal properties of SL seeds (AU Grazer™ and Serala cultivars) were determined as a function of moisture content for a moisture range from 8.57% to 26.53%, wet basis. The length, width, arithmetic mean diameter, geometric mean diameter, surface area, volume, and 1000 seed mass of both the seeds increased as the moisture content increased. Bulk density and unit density decreased as the moisture content increased. The sphericity of SL seeds decreased with increasing moisture content. Serala seeds were characterized by a higher aspect ratio than AU Grazer™. The angle of repose of SL seeds increased, while the compressibility index decreased in the moisture range. For color, the L* values of SL seeds decreased while the a* values increased with the increase in moisture content. A decrease in the b* values was insignificant. The thermal conductivity and specific heat of SL seeds decreased, whereas, thermal diffusivity increased as the moisture content of SL seeds increased. Serala seeds were characterized by higher values of thermal conductivity and volumetric specific heat than AU Grazer™. Keywords: Engineering properties, Moisture content, Physical properties, Seeds, Thermal properties.

Artificial neural networks (ANN) and traditional regression models were developed for prediction of thermal properties of sweet sorghum bagasse as a function of moisture content and room temperature. Predictions were made for three thermal properties: 1) thermal conductivity, 2) volumetric specific heat, and 3) thermal diffusivity. Each thermal property had five levels of moisture content (8.52%, 12.93%, 18.94%, 24.63%, and 28.62%, w. b.) and room temperature as inputs. Data were sub-partitioned for training, testing, and validation of models. Backpropagation (BP) and Kalman Filter (KF) learning algorithms were employed to develop nonparametric models between input and output data sets. Statistical indices including correlation coefficient (R) between actual and predicted outputs were produced for selecting the suitable models. Prediction plots for thermal properties indicated that the ANN models had better accuracy from unseen patterns as compared to regression models. In general, ANN models were able to strongly generalize and interpolate unseen patterns within the domain of training.

Stevia (Stevia rebaudiana Bertoni) has recently received a lot of attention as a sweetener due to its taste and low calorific value. Flow and thermal properties of foods play a significant role in the quantitative analysis of unit operations in the food industry. However, there are no published data available on flow and thermal properties of stevia powder. Powder Flow Tester and KD2 Pro Thermal Properties Analyzer were used to determine the flow and thermal properties of stevia powder, respectively, at different moisture contents (4.96%, 9.68%, 13.99%, 20.08%, and 25.79%, w.b.). Mean angle of internal friction of stevia powder ranged from 41.13° to 46.3°. The mean effective angle of internal friction ranged from 47.8° to 52.5° and the mean flow index ranged from 0.27 to 0.48. Mean thermal conductivity of stevia powder ranged from 0.091 W·m-2·K-1 to 0.115 W·m-2·K-1. Mean thermal diffusivity ranged from 0.103 mm2·s-1 to 0.121 mm2·s-1 and mean volumetric specific heat ranged from 0.865 MJ·m-3·K-1 to 1.019 MJ·m-3·K-1. Polynomial regression models were developed to predict flow and thermal properties of stevia powder using moisture content of stevia powder.