No abstract

The quality of sesame (Sesamum indicum L.) seeds is directly influenced by their physical characteristics, which are seldom studied notwithstanding their extreme importance in the entire production chain. Therefore, the objective of this study was to quantify the physical properties of two types of sesame seeds, collected at three points in the plant with different maturation levels, measured with digital caliper, and to evaluate the feasibility of using a digital image to determine their physical characteristics. The seeds were initially evaluated for water content and mass of 1000 seeds, and later with the data of the characteristic dimensions A (length), B (width), and C (thickness), obtained by a caliper and digital images, we determined their sphericity, circularity, projected area, and geometric diameter. We observed that water content did not affect the physical properties of the cream (CNPA G4) and black sesame cultivars. In addition, seeds of the black cultivar presented higher results than the seeds of the cream cultivar for the mass of 1000 seeds (2.7 ± 0.08 g), sphericity (58.8 ± 0.47%), projected area (4.03 ± 0.12 mm 2 ), and geometric diameter (1.65 ± 0.03 mm). Seed batches harvested after 70% maturation had the highest mass of 1000 seeds (2.7 ± 0.12 g). The results of the physical analyses of sesame seeds performed with caliper and digital image are equivalent, which shows that digital images can be used as tools to obtain the physical properties of seeds.

The objective of this work was to evaluate the nutrition and agronomic characteristics of common bean and castor bean under intercropping subject of nitrogen fertilization in top dressing. A randomized block design in a 2×2×4 + 4 factorial scheme was used, and there were three replicates. The treatments consisted of two common bean cultivars (Pontal and Pérola), which were intercropped with two castor bean cultivars (Energia and Paraguaçu), and combined with four nitrogen treatments (0, 50, 100 and 200 kg ha-1). Four additional treatments involved bean and castor bean cultivars at a single dosage of 40 kg ha-1 nitrogen. The nitrogen, potassium, calcium, magnesium and sulfur contents in castor bean intercropped with common bean leaves were influenced by nitrogen treatments. For common bean applied as top dressing, the maximum grain yields were 1,122 and 1,024 kg ha-1 for cultivars (cvs.) Pontal and Pérola, respectively, with a dose of 100 kg ha-1 nitrogen. Similar results were observed for castor bean, for whom 100 kg ha-1nitrogen provided the largest number of bunches and number of berries per bunch and the highest grain yield. The maximum values observed were 38 and 27 bunches per plant, 27.6 and 35.4 berries per bunch and 1,474 and 1,286 kg ha-1 grain yield for cvs. Paraguaçu and Energia, respectively.

To obtain quality milk, several hygiene measures must be taken during the milking process, especially cleaning the milking parlor and equipment using hot water. Thus, the objective of this study was to carry out the sizing and economic feasibility of two solar water-heating systems: flat plate solar collector (FPC) and evacuated tube solar collector (ETC) to clean milking parlors in the interior of Brazil. The sizing and economic feasibility of applicability of this study was carried out for a dairy farm located in the city of Anápolis-GO, Brazil. We calculate the energy produced by the solar collector, the necessary number of collectors, the net present value (NPV) and the time of return (RT) for all systems. The ETC presented higher energy produced per unit area (8590 to 12 979 kJ m-2 day-2) than the FPC (6472 to 8699 kJ m-2 day-2). Furthermore, it presented a total required area around 33.5% lower when compared to the FPC. The system that obtained the lowest total cost was the ETC with approximately US$ 34 441.00. The two systems had positive NPV, and for ETC, this value was 7.2% higher. The return times for FPC and ETC were 3 years and 2 months and 2 years and 10 months, respectively. Both systems have proven their economic viability for heating water from milk producing properties, and may be an option for regions without energy access. In addition, the use of these systems contributes to the reduction of production costs and environmental impacts.

The conditions of temperature and airflow distribution in the mass of stored grains are highly influenced by the configuration of the aeration ducts. However, silos are large structures, and the physical experiments on them become expensive and slow. Thus, this study aimed model and evaluate the temperature and airflow distribution in a maize mass, stored in a metal silo with different geometries of aeration ducts, using CFD (computational fluid dynamic). CFD was used to model and evaluate aeration ducts of square, ring, double bar and single bar shape. The proposed model was validated from experimental data. The airflow distribution and temperature in the grain mass were analyzed at different points. The ducts of a square and a ring shape showed better distributions of airflow in the grain mass, with averages of 0.00236 m s-1 and 0.00275 m s-1, respectively. The square shape aeration duct, presented better temperature values in the middle layer of the grain mass during aeration, with average 25.09 °C. CFD can be used in decision making for the best design of a silo, saving financial resources and time, as long as the parameters used in the simulation are reliable and represent the reality.