Resumo em Inglês:

ABSTRACT A type of weeding device was designed to solve the problems of weeders in paddy fields, such as high rice seedling damage and low weeding rate. The structure of the weeding machine and the working principle are illustrated. The seedling avoiding and weeding mechanism of the weeding device were analyzed. The parts of the weeder that contacted the soil were designed. The contact process between the spring tine and soil in paddy was simulated using the discrete element method to study the change in mechanical behavior during the working process. To verify the performance of the weeding machine, the forward speed and hoeing depth were taken as experimental factors, and weeding rate and rice seedling damage rate were selected as test indices. Field experiments were conducted to study the effects of each factor on weeding operations. The results of the experiment were evaluated by multi-index comprehensive weighting. The test results showed that, when the forward speed was 0.30 m/s and hoeing depth was 40 mm, rice seedling damage rate was 3.4%, weeding rate was 85%. The weeding machine satisfies the requirements of weeding in paddy. This research can provide a reference for the design of intra-row weeding devices in paddy.

Resumo em Inglês:

ABSTRACT Among the shortcomings of the existing pipette cartoning technology, first, it needs a lot of manpower and time to complete by hand; second, it is based on a semi-automatic equipment for loading the suction heads, which cannot ensure that the suction head is upright (bottom tip down) or avoid the phenomenon of suction head overlapping. Based on this, an automatic system for packing pipette suction heads is proposed. Firstly, the research status of pipette cartoning is analyzed; secondly, the mechanical design of the automatic cartoning system for pipette suction heads is given; thirdly, the hardware structure diagram and software flow of the automatic cartoning system are given. Finally, the system is applied to a pipette suction head box in a school laboratory. After many times of practice, it is proved that the system can realize the automatic pipette suction head box, and has the advantages of stable performance, accurate positioning and intuitive display, which improves the efficiency of the pipette suction head box in the laboratory.

Resumo em Inglês:

ABSTRACT Camellia oleifera oil is easily absorbed by the human body and has a high development prospect in the research and development of new drugs. However, the labor intensity involved in picking has limited the development of the camellia oil industry. Vibratory mechanized harvesting is considered to be an effective way to solve harvesting difficulties. In this study, the whole process of accelerating the mechanical vibration picking is analyzed theoretically, according to different vibration positions (height), and a vibration picking experiment is carried out. The ratio of the optimal excitation location to the years of growth of Camellia oleifera was found to be between 16 and 20. It was observed that with the increase of camellia growing years, this ratio gradually decreased, and its optimal vibration position showed an increasing trend. Further, when the excitation time was greater than 8 s, the fruit removal rate did not continue to increase, but the buds and leaves falling continued to decrease. This study can effectively improve the efficiency of camellia oil fruit picking and reduce the drop-off of camellia buds and leaves.

Resumo em Inglês:

ABSTRACT To solve the poor fitting degree of errors in multiobjective parameter optimization and low accuracy, a multiobjective optimization method based on a BP neural network was proposed. By taking the 1ZT-210 type whole-straw returning device as the research object, a BP neural network model on power consumption, straw returning rate and the influencing factors was obtained. By optimizing the model by the proposed method, the optimal parameter combination of the test factors was as follows: the advancing speed of the device was 0.65 km/h, the blade roll rotating speed was 210 rpm, the blade installation angle was 55o, the minimum power consumption was 9.82 kW and the maximum straw returning rate was 93.23%. Under such test conditions, the minimum power consumption was 10.75 kW, and the straw returning rate was 92.46%, which were all better than those obtained by the regression analysis method. Finally, a verification test was conducted on the results of BP neural network optimization. The power consumption of the test was 10.04 kW, the absolute error was 0.22 kW and the relative error was 2.24%. For a straw returning rate of 93.11%, the absolute error was -0.12% and the relative error was 0.13%. The test results indicated that the optimization method was feasible.

Resumo em Inglês:

ABSTRACT The use of ultra-coarse droplets for herbicide application reduces the risk of drift but may compromise the coverage and efficacy of the treatment. The objective of this work was to evaluate the use of ultra-coarse droplets, in different spray volumes, in the application of dicamba herbicide in association with glyphosate, for the control of weeds in two field trials. The first trial was conducted in a 5 x 2 factorial design, with five spray volumes (58, 72, 96, 144, and 177 L ha-1) and two air induction flat-fan spray tips (MUG 110015 - MagnoJet and TTI 110015 - Teejet). The control efficiency of Commelina benghalensis and the spray deposition on the target were evaluated by detecting a tracer using spectrophotometry. The second was conducted in a 2 x 2 factorial scheme, using two volumes (100 and 125 L ha-1) and two tips (MUG 11002 and TTI 11002). The control efficiency of Conyza spp. and fresh matter were evaluated. The different spray volumes and tips did not differ in relation to the deposition of the tracer. The use of ultra-coarse droplets was adequate for weed control. The TTI and MUG tips gave similar and adequate control performance starting at 96 L ha-1. Increasing the volume above 100 L ha-1 did not result in better control.

Resumo em Inglês:

ABSTRACT The defects that drying in concrete yards impose on coffee beans and the search for gourmet coffee production have prompted the emergence of new drying technologies. This work verified the technical and economic feasibility of drying coffee with dehumidified air with a refrigerating capacity of 422,908.7 J s-1, compatible with static capacity dryers equal to 75 m3. Considering the sale price of coffee, the cost of electric energy acquisition, the monthly interest rate and maintenance time, expenses that are equivalent to the depreciation of the concrete yard, a central compound rotational design was considered with 28 tests for the feasibility analysis, including the internal rate of return, net present value and the return on investment. The results showed that in the electric drying units, the dried coffee presents fewer broken and defective beans and has higher retention in a No. 17 sieve. With a higher beverage quality and a price 12.11% higher, drying with dehydrated air showed a PBD of 2.27 years and a return of US$ 2.49 million. The optimisation results were 98.98% desirable. It was concluded that it is economically feasible to dry coffee with dehydrated air and without using a concrete yard.

Resumo em Inglês:

ABSTRACT The seed sector faces several challenges when it comes to ensuring a quick and accurate decision making when working with large amounts of data on physiological quality of seed lots, which makes the process time-consuming and inefficient. Thus, artificial intelligence (AI) emerges as a new technological option in the seed sector to solve database problems in the post-harvest stages. This study aims to use machine learning to classify maize seed lots. Data were obtained from eight maize seed crops from a private company. These data were mined using the following classifiers: J48 (DecisionTree), RandomForest, CVR (ClassificationViaRegression ) , lBk (lazy.IBK), MLP (MultiLayerPercepton), and NäiveBayes. Cross-validation was used for data measurement, with the data set, including training and testing data, being divided into 10 subsets. The described steps were performed using the Weka software. It is concluded that results obtained allow the classification of maize seed lots with high accuracy and precision, and these algorithms can better classify the maize seed lot through vigor attributes, thus enabling more accurate decision making based on vigor tests on a reduced evaluation time.

Resumo em Inglês:

ABSTRACT The aim of this study was to characterize buckwheat flours produced using different processing methods, including with or without tegument removal and sieving with different mesh sizes. Flour A was produced by milling clean grains without husks or any other waste derived from peeling and separation processes and by sieving using 0.21-mm sieves. Flour B was a by-product of flour A, with grain size measuring 0.21–0.25 mm. Flour C was produced by milling whole grains, which after grain separation using 0.21-mm sieves resulted in a fine, whole-grain flour. Flour D was produced from what remained in the 0.21-mm sieves after sieving flour C and was processed using 0.25-mm sieves. Flours were assessed regarding water content, water activity, pH, acidity, color, microscopic characteristics, and protein and ash content. The study design was completely randomized, and differences were tested using an analysis of variance and comparison-of-means tests. Milling and separation procedures changed most quality parameters, except for water activity. Flour D contained the largest proportion of crude protein (19.87%) and showed high solubility and darker coloration than the other flours. The results of this study may be of relevance for consumers and for commercial buckwheat processing to optimize processing methods for food manufacturing.

Resumo em Inglês:

ABSTRACT This study aimed to evaluate the influence of management times and methods of black oat straw on corn crop development and yield under a no-tillage system for two crop seasons. A randomized block design was used with twelve treatments. They were arranged in a 3 x 4 factorial scheme with four replications, consisting of a combination between three methods (crushed, rolled, and desiccated) and four times (0, 10, 20, and 30 days before corn sowing). Black oat was evaluated for dry matter, while corn was for plant final population, height, stem diameter, ear insertion height, ear diameter, ear length, grain number per row, 1000-grain weight, and grain yield. All management methods and times interfered with corn crop yield components, but not all influenced final production. The method with the largest final corn population was not the same with an improved ear development. Such findings, however, may not be the same under highly favorable weather conditions.

Resumo em Inglês:

ABSTRACT This study used a spectral index method and an artificial intelligence algorithm to quantitatively analyze rice canopy soil and plant analyzer development (SPAD) based on ground nonimaging spectral data and UAV hyperspectral images to build a high-precision SPAD prediction model for nondestructive monitoring of the chlorophyll relative content of rice in cold regions. First, this study First, this study selected characteristic bands sensitive to SPAD using uninformative variable elimination and the successive projections algorithm. Then, the correlation between commonly used vegetation indices and SPAD was analyzed. Finally, this study constructed a back propagation neural network (BPNN) model, BPNN with particle swarm optimization (PSO-BPNN) model, and BPNN with genetic algorithm optimization (GA-BPNN) model, and then verified the reliability of these models. According to the results, GA-BPNN had the best predictive effect. The coefficient of the determination reached 0.818, and the root mean square error was 0.847. GA-BPNN model combined with UAV hyperspectral images were used for inversion mapping; the predicted range of SPAD was 33.1–41.2, which is in good agreement with the measured value (32.7–40.6). The inversion of regional rice canopy SPAD by nonimaging spectral data and UAV hyperspectral images had high credibility, which provided technical support for the scientific management of rice in a cold region.

Resumo em Inglês:

ABSTRACT Temperature variation in egg incubation can negatively affect the hatching time and weight gain of chicks, hence improving the incubator temperature accuracy can improve hatching rates. Controllers based on the fuzzy methodology have shown great potential for use in controlling incubator temperature variations. Therefore, the objective of this study is to develop and evaluate a fuzzy logic-based controller for egg incubation. Four identical incubators were configured: two with a fuzzy controller and two with a conventional controller. After evaluation and validation, a case study of the incubating eggs of free-range chickens was conducted on where 12 incubation cycles consisting of 20 eggs per incubator. The variables obtained include hatchability and electricity consumption. The results showed that the fuzzy logic-based controller maintained uniform internal temperature and a 10.68% saving on electricity usage when compared with the conventional controller. Thus, the fuzzy methodology has great potential for use in the incubation of free-range eggs.

Resumo em Inglês:

ABSTRACT The wear rate of spray nozzles affects several factors. This study aimed to investigate the influence of spray nozzle wear rate on droplet characteristics, such as droplet size, droplet homogeneity, droplets prone to drift, and flow rate variation. Eight hydraulic nozzles models (AIXR-110-02, JSF-110-02, TT-110-02, DG-110-02, XR-110-02, ADI-110-02, XR-110-02, and AI-110-02) were subject to an accelerated wear test, and their effects were measured at six experimental wear times (0, 10, 20, 30, 40, and 50 hours). The following variables were evaluated: volume median diameter, percentage of spray volume containing droplets smaller than 100 μm (prone to spray drift), flow rate (L min-1), and relative span, which indicates droplet size homogeneity. The droplet population was measured using a laser particle size analyzer. The use of the spray nozzle tip influences the quality of the spray application due to the wear rate. This study revealed a linear increase in the flow rate and volume median diameter as functions of the wear rate increment. The droplet size increased over the wear time, which consequently modified the volume percentage of droplets smaller than 100 μm and significantly increased the relative span.

Resumo em Inglês:

ABSTRACT Estimating peak streamflows in a basin is an essential issue in hydrology, especially for projects and management of hydraulic infrastructures such as dams, spillways, and bridges. In this context, this article presents a regionalization of annual maximum streamflows for the upper and middle Paraopeba River region in Minas Gerais, proposing a regional equation to calculate maximum streamflows using the index-flood technique by the generalized extreme value (GEV) distribution. GEV distribution parameters were estimated using the L-moments method, and the adjustment of the statistical model was performed by applying the Anderson-Darling test. The results of the hydrological regionalization were compared with those obtained by the local frequency analysis, performed for the considered fluviometric stations, observing absolute deviations from 11.91 to 58.78%.

Resumo em Inglês:

ABSTRACT The parameter optimization of the tractor's steering trapezoid mechanism is a traditional optimization problem, and the teaching-learning-based optimization (TLBO) has a better solving ability for parameter optimization of the tractor's steering trapezoid. However, the teacher stage and student stage of TLBO limit the accuracy and stability and the ability to jump out of the local optimization solution. To obtain an optimal solution with an higher accuracy, an improved adaptive direction strategy teaching-learning-based optimization (IADS-TLBO) was used. This improved the feedback stage based on the adaptive direction strategy teaching-learning-based optimization (ADS-TLBO). The IADS-TLBO was verified by three different testing functions, and the results showed that the improved ideas are valid and feasible. Finally, the IADS-TLBO was used to optimize the steering trapezoid mechanism of JOHN DEERE T600. The optimal parameters obtained were as follows: the bottom angle was 35.4º, and the steering arm length was 154 mm. A verification experiment was conducted in the farm tool laboratory of Northeast Agricultural University (China). The experimental results showed that the average bottom angle was 35.48º, and the relative error between the measured and optimized bottom angles was 0.23%, which is less than 5%. This result showed that the results obtained by IADS-TLBO were reliable.

Resumo em Inglês:

ABSTRACT Iron mining tailings have limitations for plant growth and development due to low fertility, coupled with great restriction of physical characteristics such as low water retention, high density, and lack of structure. This study aimed to evaluate whether different irrigation depths applied to Xaraés grass grown in mining tailings influence its yield and bromatological aspects. The experiment was carried out in a completely randomized design with five irrigation depths (40, 60, 80, 100, and 120% of the crop evapotranspiration), two additional treatments consisting of grass grown in tailings with soil conditioner and in natural soil, and three repetitions. Forage dry mass, plant height, leaf: stem ratio, as well as neutral detergent fibre, acid detergent fibre, crude protein, and mineral matter content, were evaluated during four cutting cycles. Xaraés grass could establish and produce forage despite cultivation limitations in iron mining tailings, which are due to their properties. Irrigation depths showed positive and linear effects on Xaraés grass dry matter yield and heights of plants grown in iron mining tailings. The soil conditioner has potential for use in pasture cultivation in iron mining tailing.

Resumo em Inglês:

ABSTRACT Despite the advantages in production, mechanization may expose workers to high noise levels in the work environment, which is considered one of the main causes of work-related hearing loss. In this sense, this study aimed to analyze the spatial variability of noise generated by a self-propelled coffee harvester in an open area to define safe zones for operators and workers involved in coffee harvesting activities. The noise source used was an Electron Auto TDI self-propelled coffee harvester (model MWM D229-4), with a cabin manufactured in 2012 and a 67-hp 4-cylinder engine, working at 1200-rpm rotation. The noise level was measured by a digital decibel meter at points distributed within a regular 2.5 x 2.5 m sampling mesh (32.5 x 35.0 m area) surrounding the harvester in operation, which was configured according to the regulatory standard. Noise level spatial dependence was analyzed through geostatistics, characterizing structure and magnitude, and mapping spatial variability. Results showed that noise levels were above the limit established by relevant legislation (i.e., 85 dB), both for operators and employees at a distance of about 5.5 m from the generating source.