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| Registros recuperados: 5.225 | |
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| Dantas,Geffson de F.; Faria,Rogério T. de; Costa,Natã R.; Santos,Gilmar O.; Ferraudo,Antonio S.. |
| ABSTRACT The response of biomass flow components of forage from the interaction between fertigation with wastewater and cutting height during the year is little known. The objective of this work was to verify the responses of morphogenic and structural characteristics of Urochloa brizantha as a function of fertigation application strategies with sewage treatment plant effluent (TSE), complemented with urea (U), associated with harvest with two plant heights during the dry and rainy periods. The forage cutting heights were 30 cm (H1) and 40 cm (H2), and nitrogen fertilization doses were 9.1 (D1), 12.1 (D2), 22.5 (D3), 26.6 (D4), and 34.0 (D5) kg of N per Mg−1 of dry matter (DM) produced, applied by TSE via fertigation, plus 7.5 kg N per Mg−1 of DM produced,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Defoliation; Nitrogen; Water reuse. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000600692 |
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| Sun,Lixiang; Yang,Yan; Ma,Fang; Jing,Wen; Zheng,Yibo; Wu,Hao. |
| ABSTRACT At present, most large machinery and vehicle engines are electronically controlled but their electronic control systems are too expensive to be popularised and applied in small gasoline engines with relatively low prices. Therefore, small gasoline engines still use mechanical speed regulators. Mechanical speed regulators not only have the defects of inertia lag, friction resistance, inherent speed regulation and the like, but also have the disadvantage that dynamic performance and steady performance cannot be combined, which is not suitable for the increasingly improved speed regulation performance of gasoline engines. This paper describes the design of an electronically controlled intelligent governor for small gasoline engines. Starting from a... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Electronic control; Intelligent perception; Dynamic and steady state performance; Power; Hunting. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000400495 |
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| Aboukarima,Abdulwahed; El-Marazky,Mohamed; Elsoury,Hussien; Zayed,Moamen; Minyawi,Mamdouh. |
| ABSTRACT One of the new crop varieties that have been adopted for high yield is the Egyptian faba bean. However, poor-quality faba bean has reduced economic value. Quality evaluation is thus important and can be performed using computational intelligence. We developed a robust method based on morphological features and artificial neural network for quality grading and classification of Egyptian faba-bean seeds, covering five varieties: Giza3, Giza461, Misr1, Nobarya1, and Sakha1. Fifteen seed morphological features were then calculated, and artificial neural networks classified faba beans into different varieties. The results indicated an overall classification accuracy of 77.5% was achieved in training phase and it was 100% when testing dataset was used.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Faba bean; Quality; Classification; Artificial neural network; Features. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000600791 |
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| Bernache,Leonardo; Tedesco-Oliveira,Danilo; Oliveira,Luan P. de; Corrêa,Ligia N.; Silva,Rouverson P. da. |
| ABSTRACT Sugarcane harvester cutting blade wear increases ratoon damages and losses, impairing sugarcane regrowth. This study aimed to evaluate the quality of basal cut using ratoon damage and loss indexes and correlating them with effects on sugarcane regrowth. Harvest parameters such as plant height and position, damage and loss indexes, and stem length were evaluated every 30 min, following statistical process control (SPC) assumptions. Blade wear was examined during three harvesting shifts (0-8 h, 8-16 h, and 16-24 h). Sugarcane regrowth was assessed by counting number of tillers and measuring plant height and stem diameter. The second harvesting shift showed better quality in terms of damage and loss indexes, and plant height and stem diameter.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Mechanized harvesting; Sugarcane; SPC; Harvester. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000100053 |
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| Fabiano,P. Branco; Marney,P. Cereda; Marco,H. Naka. |
| ABSTRACT Brazil is home to several plant species that exhibit potential for starch extraction. The arrowroot plant stands out owing to its South American origin. Arrowroot starch is especially important for fine confectionery, which is a high-value niche market. Thus, a small producer could benefit from the high prices of arrowroot starch. However, to have consistent production, the extraction should be performed using simple, safe, and inexpensive equipment. Starch extraction involves disintegration of the raw material under water, followed by the separation of fibrous bagasse from the starch–water suspension. This study presents an equipment design based on the concept of appropriate technology that is suitable for small producers to extract starch. A... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Efficiency; Yield; Machine project; Water consumption; Granulometry. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000100090 |
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| Minhoni,Renata T. de A.; Pereira,Francisca F. S.; Silva,Tatiane B. G. da; Castro,Evanize R.; Saad,João C. C.. |
| ABSTRACT The Darcy-Weisbach equation is the most recommended equation for determining the pressure loss in pressurized pipes because of its wide applicability. However, one of the largest obstacles to implementing this equation is the friction factor (f) calculation. This factor can be precisely determined using the Colebrook equation, which is implicit. Thus, the objective of this study was to compare six explicit equations for calculating the Darcy-Weisbach friction factor with the implicit Colebrook equation based on the relative error. Based on the results, the equations of Vatankhah and Offor & Alabi were the most highly recommended. These six explicit formulas showed a mean relative error of less than ± 1% compared to the Colebrook equation,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Absolute roughness; Colebrook equation; Forced conduits; Head loss; Hydraulic load; Reynolds number. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000200258 |
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| Ma,Fulong; Li,Lekai; Wang,Yutan; Li,Ping; Zhu,Chaowei. |
| ABSTRACT To improve the picking rate and reduce the wrong picking rate of the existing wolfberry harvesting machinery, in this study, the binding force and physical appearance of the immature fruit stalk, mature fruit stalk, flower, and leaf were studied to guide the designing of new-generation wolfberry harvesting machinery and lay theoretical foundation for further studies on biomechanical properties of wolfberry. By preprocessing the experimental data with the Pauta criterion, the distribution range of the binding force and physical appearance of stalk were obtained; the binding force was not influenced by the picking temperature, mass of the fruit, and location of the branch of the fruit. The length-diameter ratio of mature fruit was confirmed by image... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Binding force; Biomechanical characteristics; Constitutive equation; Dynamic model; Vibrating wolfberry harvesting machinery. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000200162 |
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| Amaral,Pedro I. S.; Campos,Alessandro T.; Yanagi Junior,Tadayuki; Cecchin,Daiane; Leite,Evandro M.; Dias e Silva,Nhayandra C.. |
| ABSTRACT Although dry bulb temperature (T) is the environmental variable most commonly used to classify thermal comfort in pigs, environmental assessment ratios provide more accurate information. The objective of this study was to correlate the sound pressure levels (SPL) produced by piglet vocalization with the thermal environment observed during the nursery phase, and subsequently establish thermoneutrality ranges. The experiment was conducted on a pig farm where T, relative humidity (RH), and SPL data were recorded between 9 am-5 pm for 42 days. The association between SPL and T in nursery phase piglets was verified; for thermal comfort to be possible, SPLs were 56.3 to 60.3 dB. The SPLs were subsequently used in predictor equations of ratios, and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ambience; Animal welfare; Nursery; Rearing; Thermal comfort. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000300266 |
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| Ferreira Junior,Weder N.; Resende,Osvaldo; Pinheiro,Gleyce K. I.; Silva,Ligia C. de M.; Costa,Eduarda R.. |
| ABSTRACT The knowledge of hygroscopicity is essential for the storage of tamarind seeds, but there is a limitation of a judicious statistical parameter to define the best mathematical model to adjust the isotherms of plant products. Therefore, this study aimed to determine the desorption isotherms of tamarind seeds and test the Akaike information criterion (AIC) and Schwarz Bayesian information criterion (BIC) for choosing the best mathematical model. Seeds with an initial moisture content of 21.00 ± 0.10% dry basis (db) were dried at 45 °C until they reached moisture contents of 17.27 ± 0.10, 15.04 ± 0.16, 14.14 ± 0.06, 12.41 ± 0.17, and 10.52 ± 0.12% db. The water activity of the product was determined by the static-indirect method at temperatures of 10,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Water activity; Hygroscopicity; Cavalcanti Mata. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000400511 |
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| Spagnolo,Roger T.; Custódio,Tiago V.; Morais,César S. de; Reis,Ângelo V. dos; Machado,Antônio L. T.. |
| ABSTRACT Pesticide environmental risks and increased weed resistance have encouraged studies for alternatives to herbicides. Among these are weed thermal control methods by controlled heat application machines. Thus, this study aimed to test a prototype of heat-applicator machine as a function of changes in gas pressure, travel speed, and tire traffic effect on plants. Then, three experimental factors were tested: gas pressure (98, 196, and 245 kPa), travel speed (0.56, 0.78, and 1.17 m s−1), and tire traffic effect on plants (with and without traffic). The results showed that tire traffic effect on plants and subsequent heat application had no effect on control rate. Weed control rates reached levels considered satisfactory using a heat application speed... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Thermal control; Agricultural machinery; Organic production. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000500595 |
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| Aviz,William L. C. de; Lima Junior,Joaquim A. de; Silva,André L. P. da; Oliveira,Pedro D. de; Gama,Cândido M. P.. |
| ABSTRACT Jambu (Acmella oleracea (L.) R.K.) is a short-cycle leafy vegetable from the Amazon region, which needs an adequate availability of water and nutrients, mainly nitrogen, to obtain a rapid mass increase. This research aimed to study the effect of different soil-water stresses and nitrogen doses on jambu cultivation in the state of Pará. The experiments were conducted at the Igarapé-Açu experimental farm of the Federal Rural University of Amazonia (UFRA). The Jamburana variety was used in a 10 × 10 cm spacing, using a randomized block design in a 4 × 4 factorial scheme with three replications. Each plot had a dimension of 0.4 × 0.5 m (0.2 m2), totaling 20 plants in 4 rows, but only the plants of the central rows were useful. Treatments consisted of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Acmella oleracea (L.) R.K.; Tensiometry; Dripping; Nitrogen fertilization. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000100016 |
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| Petry,Mirta T.; Basso,Laudenir J.; Carlesso,Reimar; Armoa,Maria S.; Henkes,Jonas R.. |
| ABSTRACT Evaluating the impacts of water stress on crop yield allows comparing irrigation management alternatives, aiming to ensure an economic return for the irrigated farms. Thus, the main objectives of this study were to model the soil water balance, deriving the crop coefficients, grain yield prediction, and economic return of soybean grown at different levels of water deficit and price quotations. The experiment was carried out under a rainout shelter, using four irrigation water managements. Irrigations were applied when the soil available water in the root zone reached 75%, 64%, 60%, and 50% of the total available water (TAW). Crop and soil parameters were monitored throughout the crop season. The SIMDualKc model was used to simulate the soil water... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Glycine max; Soil water balance; SIMDualKc model; Economic return. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000400526 |
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| Stolf,Rubismar; Oliveira,Ana Paula Rodrigues de. |
| ABSTRACT The National Alcohol Program (Proálcool) was a strategic policy of the Brazilian government to replace petroleum-based fuels with alcohol (ethanol). Based on the review, we can choose the 1960s as a start point for a leap in development. Over the 500 years of sugarcane history in Brazil, the crop enters the second decade of the 21st century with extraordinary strength and prestige, reaching its highest production in history. This made Brazil a leader in sugar and ethanol productions worldwide, with an energy-independent agribusiness. Moreover, effluents and polluting wastes were transformed into high-value inputs (e.g., vinasse, filter cake, and others). Environmentally friendly actions included developing organic cane production technology,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Strategies; Development; Agribusiness; World leadership. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000200243 |
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| Resende,Mariana; Cirillo,Marcelo Â.; Borém,Flávio M.. |
| ABSTRACT Numerous factors are related to the individual sensory perception of consumers, which makes it impossible to adapt a model that explains their behavior. In this context and given the scarcity of statistical indexes that evaluate preferences for specialty coffees, new statistical methods should be studied. To this end, our study aimed to create an index that measures the acceptance of specialty coffees. The index was built considering the fit of regression models as a function of principal component scores. Validation was done by significance tests, whose probabilities were obtained by bootstrapping, considering the main measures used in diagnosing outliers as weights, with application to real data from different consumer groups. The coffee... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Models; Quality; Bootstrap; Acaia; Bourbon. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000500624 |
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| Registros recuperados: 5.225 | |
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