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Engenharia Agrícola, Volume: 42, Número: 2, Publicado: 2022
  • CONTINUOUS AND IMPACT CUTTING SYSTEMS FOR SUGARCANE HARVESTER Scientific Paper

    Marques Filho, Aldir C.; Testa, João V. P.; Moura, Michel S.; Martins, Murilo B.; Lanças, Kléber P.

    Resumo em Inglês:

    ABSTRACT The quality of the basal cut of sugarcane during harvest can affect the longevity of the crop, and the cutting tool is one of the main causes of damage during harvesting. The aim of this study was to evaluate the performance of two cutting tools: an impact cutting system (ICS) using knives and a continuous cutting system (CCS) using saws. Laboratory tests were carried out to obtain the stalk damage index at different device travel speeds and to determine the invisible losses caused by each cutting system. The results showed that both cutting systems presented acceptable levels for the stalk damage index; however, the CCS obtained better cut quality, corresponding with decreased general damage. The invisible losses caused by the cutting tools in relation to the total harvested mass were 0.52% and 0.54% for the CCS and ICS, respectively. The highest invisible losses were obtained at speeds of 2, 3, and 4 km h-1 for the ICS, showing a statistical difference in relation to the CCS. No statistical difference was noted for both the systems at 5 and 6 km h-1.
  • SIMULATION OPTIMIZATION AND EXPERIMENTAL STUDY OF THE AIR DISTRIBUTION CHAMBER STRUCTURE OF STRAW-BASED NUTRIENT SEEDING-GROWING BOWL TRAY MICROWAVE–HOT-AIR COUPLING DRYERS Scientific Paper

    Li, Haiyuan; Hu, Yuhui; Qi, Lianxing; Yu, Haiming

    Resumo em Inglês:

    ABSTRACT To improve the flow field structure of the air distribution chamber of the microwave–hot-air coupling dryer for a straw-based nutrient seeding-growing bowl tray and enhance the uniformity of the outlet gas velocity distribution, computational fluid dynamics software was used to simulate the flow field of the air distribution chamber based on the gas motion differential equation and the (RNG) k–ε turbulence model. Using the front panel height, upper apex angle, and side wall inclination angle as factors and the speed nonuniformity coefficient as the index, the results showed that when the air distribution chamber front panel height was 33 mm, the upper apex angle was 108°, the side wall inclination angle was 78°, the height of the two spoilers was 40 mm, the outlet airflow speed varied from 5.36 to 5.71 m/s, and the speed unevenness coefficient was reduced from 13.95% in the original model to 6.05%. The maximum deviation between the numerical simulation results and test data was less than 4%, which met the uniformity requirement of the outlet airflow speed of the dryer. The results provide theoretical support for the design and industrial production of microwave–hot-air coupling dryers.
  • APPLICATION OF NEAR INFRARED SPECTROSCOPY COMBINED WITH MULTIVARIATE ANALYSIS FOR SCREENING FOLIAR MAIN ESSENTIAL OIL COMPONENTS IN BAY LAUREL Scientific Paper

    Çeliktaş, Nafiz; Kaya, Alpaslan; Türkmen, Musa

    Resumo em Inglês:

    ABSTRACT Ground bay laurel leaf samples (10–15 g) were scanned using Fourier-transform near-infrared (FT-NIR) spectrometer with reflectance mode in the 1000–2500 nm wavelength range. According to the wet chemical analyses, the essential oil content of the samples from different locations varied between 1.77 and 5.30%. The major component of essential oil was 1-8 cineole with a concentration of 43.4–58.1%. The regression coefficients of calibration (R2CAL) and validation (R2VAL) for essential oil and 1-8 cineol content with partial least square regression (PLSR) actualized as 0.96–0.98 and 0.98–0.98, respectively. The prediction accuracy of the final NIRS model was reasonable, with acceptable root mean standard errors of prediction (RMSEP) of 0.18% and 0.45%. According to the residual predictive deviation (RPD) index (3.58 and 8.41), the accuracy of the NIRS models was regarded as the best. The PLSR model differentiated bay laurel genotypes very well on the first principal component (PC1), based on the related properties.
  • LAND-USE AND LAND-COVER MAPPING USING A COMBINATION OF RADAR AND OPTICAL SENSORS IN RORAIMA – BRAZIL Scientific Paper

    Maffei Valero, Miguel A.; Araújo, Wellington F.; Melo, Valdinar F.; Augusti, Mauricio L.; Fernandes Filho, Elpídio I.

    Resumo em Inglês:

    ABSTRACT Land-use and land-cover (LULC) are important environmental properties of the Earth’s surface. Satellite platforms and state-of-the-art algorithms enable the mapping of large areas, but they still need to be improved. This study aimed to compare free- and open-access images from radar and optical sensors, using the Google Earth Engine™ (GEE) for supervised classification of LULC for five municipalities in Roraima State, Brazil. Sentinel-1 (S1) scenes were used along with Landsat 8 (L8) and Sentinel-2 (S2) ones, resulting in five classification approaches S1 (SD), L8 (ODL), S2 (ODS), S1+L8 (SODL), and S1+S2 (SODS), with an auxiliary ALOS World 3D dataset (DEM≈30m). Accuracy was assessed by an error matrix. The SD approach was significantly different (P ≤ 0.01) from the others using a mean F1-score of 0.80. ODL and ODS had barely perceptible differences (P ≤ 0.1), showing F1-scores of 0.95 and 0.92, respectively. When comparing ODL (F1=0.95) and SODL (F1=0.95) no difference was found (P > 0.1). However, by comparing ODS (F1=0.92) and SODS (F1=0.94), there was a significant classification improvement (P ≤ 0.05). In short, the approaches SODL and SODS had the best pixel-based supervised classification performance.
  • CROP CLASSIFICATION BASED ON A GAOFEN 1/WIDE-FIELD-VIEW TIME SERIES Scientific Paper

    Jia, Yinjiang; Zhang, Xiaoyu; Zhang, Huaijing; Su, Zhongbin

    Resumo em Inglês:

    ABSTRACT The accurate acquisition of crop planting area information allows for agricultural management departments to understand crop production information promptly. Concurrently, support vector machine (SVM) algorithms are unable to determine parameter combinations in remote sensing image crop classification to obtain optimal classification results. To solve this issue, this paper proposes an SVM that is optimized by the adaptive mutation particle swarm optimization algorithm. To test the algorithm, we undertook an experiment in Acheng District, Harbin City, Heilongjiang province, China, using Gaofen 1/wide-field-view satellite images to construct a time series for various vegetation indices. The SVM model with optimized parameters was compared with a traditional backpropagation neural network, a decision tree, and an SVM without parameter optimization. The experimental results verified that the improved SVM model obtained the highest classification accuracy.
  • 3D FINITE ELEMENT ANALYSIS OF THE TILLAGE AND STRAW CUTTING PERFORMANCE OF A CURVED-EDGED TOOTHED DISC Scientific Paper

    Torotwa, Ian; Ding, Qishuo; Alele, Joseph Odero; He, Ruiyin

    Resumo em Inglês:

    ABSTRACT The management of crop residues together with compacted soil under intensive farming systems requires highly efficient and well-adapted tools. The performance assessment of such tools requires proper definition of their technical designs as well as the tool-induced soil-straw dynamic interactions. Few studies have characterized the performance of toothed discs based on their design considerations and mechanical responses. This study evaluated the tillage forces, structural strength, straw-cutting performance, and tillage-depth uniformity of a curved-edged toothed disc in comparison to a straight-edged toothed disc. The design of the curved-toothed disc was inspired by the arc-shaped structure of the mole-rat's claw. 3D finite element analysis (FEA) was used to simulate the discs’ interactions with soil and straw. Field experiments were conducted to validate the FEA results. It was revealed that the curved disc reduced the tillage forces by up to 22.8%, and significantly reduced the stresses on the tool. The disc also achieved uniform tillage depths and improved the straw-cutting efficacy by up to 26.31%. Bionic curved cutting-profiles on toothed discs thus provide a structurally enhanced, energy-efficient option for effectively managing crop residues and improving seeding performance in no-till conservation farming.
  • NUMERICAL APPROACH FOR PREDICTION OF AIRFLOW BEHAVIOR IN COFFEE BEAN MONOLAYERS DURING DRYING PROCESS Scientific Paper

    Bustos-Vanegas, Jaime Daniel; Aragón, Larissa; Gutiérrez-Guzmán, Nelson; Córdoba, Nancy

    Resumo em Inglês:

    ABSTRACT The homogeneity and efficiency of moisture removal from coffee beans depend on the airflow patterns inside the drying chambers used for drying. This study aimed to implement a porous medium model to simulate the airflow through mesh trays containing parchment and ripe fruit coffee ( Coffea arabica L.) using computational fluid dynamics (CFD). The geometry of the ripe fruit and parchment coffee beans was simplified as spherical and semi-ellipsoidal, respectively. The pressure drop in the normal direction to the monolayer was calculated as the average pressure of the normal planes located 1 mm before and after the bean layer for different air velocities. The viscous and inertial terms were adjusted by nonlinear regression for each case and incorporated into the Navier–Stokes equations as subdomains. The pressure drops calculated by the porous medium model and those calculated using the bean layers presented a good fit. The modeling of the trays as porous media can help reduce the computational resources required for CFD simulations while maintaining an acceptable accuracy.
  • THERMODYNAMIC PROPERTIES OF THE WATER ADSORPTION PROCESS IN BARU FLOURS Scientific Paper

    Arruda-Silva, Thiago A.; Alves, Niédja M. C.; Galle, Nahyara B. C.; Santos, Silmara B. dos; Andreatta, Evelise

    Resumo em Inglês:

    ABSTRACT Baru almonds and their byproducts have gained popularity in the population diet because of their high nutritional values. Despite this, there is limited information on how to store their flours properly, particularly their whole and partially defatted flours. Thus, this study aimed to use the Guggenheim–Anderson–de Boer (GAB) model to determine the thermodynamic properties of enthalpy, entropy, and Gibbs’s free energy variation, as well as the spreading pressure, all of which are inherent to the moisture adsorption process in baru flours. The oil content, ash content, moisture content, pH, and wettability of the baru flour samples were characterized. The adsorption isotherms were determined using the static gravimetric method at temperatures of 298.15, 303.15, and 308.15 K and adjusted to the GAB model. The differential enthalpy variation was positive and decreased as the moisture content in the flours increased, whereas the differential entropy variation exhibited an opposite trend. The isokinetic theory was validated, as the process was driven by entropy. The spreading pressure increased as water activity increased.
  • DESIGN OF A SINGLE SOWING DEPTH MEASUREMENT SYSTEM FOR AN AIR SUCTION CORN PLANTER Scientific Paper

    Liu, Wei; Ma, Biao; Chen, Xuehui; Yu, Chuanyang; Jing, Tiantian; Huang, lei

    Resumo em Inglês:

    ABSTRACT To accurately measure sowing depth, we designed a multisensor data fusion algorithm based on the Kalman filter and applied it to a dual-channel ultrasonic sowing depth measurement system. We installed two ultrasonic sensors on the frame above the depth limit wheel and the soil covering-compacting wheel. The terrain-like plate was installed on the central axis of the depth limit wheel to simulate the surface relief and calculate the seeding depth value. The Kalman filter algorithm filters out the clutter generated when the two ultrasonic sensors collect the depth data and then fuses the two ultrasounds of the filtered data. The test shows that when the vehicle speed is 4 km/h , the fluctuation ranges of the collected data of ultrasonic 1 and 2 are 45-60 mm and 35-70 mm , respectively, and the fluctuation ranges of the filtered data are 52-58 mm and 48-60 mm , respectively. After data fusion processing, the data fluctuate in a small range of approximately 55 mm . When the vehicle speed is 6 km/h and 8 km/h, the obtained results have the same trend as the experimental results at 4 km/h . The results show that the sowing depth measurement system is effective.
  • SURFACE MOISTURE INDEX BY RADIOMETRIC MEASUREMENTS AND ORBITAL DATA Scientific Paper

    Schirmbeck, Lucimara W.; Fontana, Denise C.; Schirmbeck, Juliano; Dalmago, Genei A.; Fernandes, José M. C.

    Resumo em Inglês:

    ABSTRACT As an indicator of surface moisture, TVDI has great potential for application in agriculture in different types of climates, but the best results have been obtained in arid climates, given the presence of areas with contrasting water conditions. Some studies under subtropical climate conditions have shown good results in the use of TVDI as an indicator of surface moisture but some uncertainties still need to be better understood. This study aimed to evaluate the coherence of temperature-vegetation dryness index (TVDI) values, obtained from sensors installed on the surface, compared to data obtained using orbital images in an agricultural area in southern Brazil under humid subtropical climate conditions. The analyses employed normalized difference vegetation index (NDVI) and surface temperature (TS) data obtained through sensors installed on the surface, with continuous monitoring, as well as Landsat OLI/TIRS images, covering the period of the soybean cycle. The TVDI values, obtained from NDVI and TS radiometric sensors installed in the field, indicated consistency of using Landsat-OLI/TIRS orbital images to map the surface moisture condition, representing the spatial and temporal variations of the water condition of soybean cultivations under subtropical climate conditions.
  • HOW DO THE DROPLET SPECTRUM UNIFORMITY AND SPRAY VOLUME OF FLAT-FAN NOZZLES INFLUENCE FUNGICIDE SPRAY DISTRIBUTION QUALITY IN SOYBEANS? Scientific Paper

    Griesang, Fabiano; Ferreira, Marcelo da C.; Spadoni, Ana B. D.; Della Vechia, Jaqueline F.; Santos, Renata T. da S.; dos Santos, Cícero A. M.

    Resumo em Inglês:

    ABSTRACT Droplet spectrum quality is essential to effectively control crop pests and diseases. This study aimed to characterize the droplet uniformity of the eight most popular flat-fan nozzles used by Brazilian farmers and relate it to their spraying quality. The method consisted of using a laser-diffraction-size analyser to determine droplet-size distribution for three fungicide spray solution compositions and at two flow rates. Our goal was to identify the nozzle models with the highest and lowest Span values for each fungicide spray solution. In the first stage, the results confirmed differences in uniformity and droplet size for both nozzle models and flow rates applied. However, these differences were not the same for both flow rates nor constant for all fungicide spray solution compositions. Through field experiments, we could understand how the combination of flow rate, nozzle model, and spray solution composition provides different results and application efficiencies. Based on our results, we can state that Span has an impact on the number of droplets prone to drift and quality of canopy coverage. Therefore, this droplet-quality parameter should be considered and displayed in nozzle catalogues to improve nozzle selection and sprayer configuration, thus enhancing application quality.
  • REMOTE DETECTION OF WATER AND NUTRITIONAL STATUS OF SOYBEANS USING UAV-BASED IMAGES Scientific Paper

    Andrade Junior, Aderson S. de; Silva, Silvestre P. da; Setúbal, Ingrid S.; Souza, Henrique A. de; Vieira, Paulo F. de M. J.

    Resumo em Inglês:

    ABSTRACT Digital aerial images obtained by cameras embedded in remotely piloted aircraft (RPA) have been used to detect and monitor abiotic stresses in soybeans, such as water and nutritional deficiencies. This study aimed to evaluate the ability of vegetation indexes (VIs) from RPA images to remotely detect water and nutritional status in two soybean cultivars for nitrogen. The soybean cultivars BONUS and BRS-8980 were evaluated at the phenological stages R5 and R3 (beginning of seed enlargement), respectively. To do so, plants were subjected to two water regimes (100% ETc and 50% ETc) and two nitrogen (N) supplementation levels (with and without). Thirty-five VIs from multispectral aerial images were evaluated and correlated with stomatal conductance (gs) and leaf N content (NF) measurements. Near-infrared (NIR) spectral band, enhanced vegetation index (EVI), soil-adjusted vegetation index (SAVI), and renormalized difference vegetation index (RDVI) showed linear correlation (p<0.001) with gs, standing out as promising indexes for detection of soybean water status. In turn, simplified canopy chlorophyll content index (SCCCI), red-edge chlorophyll index (RECI), green ratio vegetation index (GRVI), and chlorophyll vegetation index (CVI) were correlated with NF (p<0.001), thus being considered promising for the detection of leaf N content in soybeans.
  • MAXIMIZATION OF PRODUCTION AND NET INCOME IN AGRO-FOREST SYSTEMS Scientific Paper

    Nascimento, Vinicius T. do; Ventura, Sergio D.; Delgado, Angel R. S.; Silva, Washington S. da

    Resumo em Inglês:

    ABSTRACT In this study, we present computational procedures to solve problems for the maximization of production and net income from crops or trees in a randomly generated agroforestry system with limited inputs, based on the Logarithmic Barrier Method. The results obtained showed numerical consistency for viability and optimality of both problems in the agroforestry scenarios tested, as well as promoted conditions to solve the problems with real data.
Associação Brasileira de Engenharia Agrícola SBEA - Associação Brasileira de Engenharia Agrícola, Departamento de Engenharia e Ciências Exatas FCAV/UNESP, Prof. Paulo Donato Castellane, km 5, 14884.900 | Jaboticabal - SP, Tel./Fax: +55 16 3209 7619 - Jaboticabal - SP - Brazil
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