Coffee Science
URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3355
Navegar
25 resultados
Resultados da Pesquisa
Item Determination of physical and mechanical properties of the coffee branch: an experimental approach(Universidade Federal de Lavras, 2022-06-09) Melo Júnior, Wellington Washington Andrade de; Santos, Fabio Lúcio; Scinocca, Francisco; Rosa, Pablo Antunes da; Magalhães, Ricardo RodriguesIn order to reduce the human efforts during manual harvesting and increase the operational capacity and quality, the mechanization of the harvesting operation has been significantly increasing in the last few years for coffee crops. Therefore, for the design of coffee harvesting machines, the physical and mechanical properties of coffee branches are of utmost importance for harvesting machines projects. In this way, using an experimental approach, the present paper analyzes the variability of physical and mechanical properties in the coffee branches, of the Coffea arabica L., cultivar Catuaí-Vermelho (IAC 144). The branches were collected in different positions, along the orthotropic branch: upper, middle and lower parts of the plant. The mass, volume, spe-cific mass, and modulus of elasticity of the collected specimens were determined considering their position in the plant and position along the branches. According to the position in the plant, no significant differences were found between the specific mass averages for the upper, middle, and lower parts of the plant. The research obtained an average of 1.24 GPa with a standard deviation of 0.13 GPa for the elasticity modulus. A significant increase in the elasticity modulus could be noted in the branches from the top to the bottom of the plant in the present research.Item Effect of flight operative height and genotypes on conilon coffee spraying using an unmanned aerial vehicle(Universidade Federal de Lavras, 2022-06-09) Vitória, Edney Leandro da; Oliveira, Ronaldo Furtado de; Crause, Deborah Hoffmam; Ribeiro, Luis Felipe OliveiraThis study analyzed the effect of operational flight height and conilon coffee genotypes in the deposition and uniformity of destruction in the plant’s can-opy. The spray were conducted using a unmanned aerial vehicle in a conilon coffee plantation. The experiment was carried out with a randomized block design and treatments arranged in a factorial scheme, with three operational flight heights in relation to the coffee canopy and three genotypes of conilon coffee (Coffea canephora). The parameters evaluated were volume median diameter (VMD), density of drops and coverage (%). The interaction between flight height variables and canopy’s range was significant for the data on VMD variables, droplet density and coverage. According to the results, spray performance at an average height of 3.0 m is better than at 2.0 and 4.0 m. At 4.0 m, we observed a decrease in these variables, and this can be explained by a possible drift caused by the wind intensity and direction at higher heights. The coverage on the genotype A1 leaves was higher when compared to the other genotypes, although flight operational height was significantly different only in this genotype, 8.1% at 4.0 m, we observed at this height the lowest coverage values.Item Technical and economic evaluation of different operating modes for mechanized fertilizer application in coffee plantations(Editora UFLA, 2020) Andrade, Alan Delon; Ferraz, Gabriel Araújo e Silva; Faria, Rafael de Oliveira; Barros, Murilo Machado de; Silva, Fábio Moreira da; Sarri, Daniele; Vieri, MarcoThe present study aimed to investigate the performance parameters and related costs of a machinery set composed of a tractor and a machine for fertilizers and soil correctives application, working in a coffee yard. It was evaluated two different operating modes. For the first operating mode (OM1), the machinery applied the total recommended dose to only one side of the plants and traveled in only half of the plot interrows. For the second operating mode (OM2), the machinery applied half the recommended dose to each side of the plants and traveled in all of the plot interrows. The study was performed at Bom Jardim Farm, located in the municipality of Bom Sucesso, state of Minas Gerais, Brazil. The performance parameters included effective field capacity and effective time. The hourly cost of the fertilizers and soil correctives application operation was determined based on the farm’s management data and the effective cost was obtained by relating the hourly cost and the effective time. The results showed that OM1 implies higher effective field capacity and lower effective cost, with the cost of only 50.1% of that found for OM2.Item Effect of the impact of rigid rods on coffee fruit detachment efficiency by mechanical vibrations(Editora UFLA, 2020) Gomes, Ely Queiroz; Santos, Fabio Lúcio; Nascimento, Moysés; Velloso, Nara SilveiraThe mechanization of field activities has been the response of coffee producers to the labor shortage, especially for fruit harvesting. The use of mechanical harvesters allows greater harvesting efficiency and ensures the economic viability of coffee plantations, which currently depend mainly on the reduction in production costs. The principle used for mechanized coffee harvesting is based on the principle of mechanical vibration. The objective of this study was to analyze the dynamic behavior of the coffee fruit-peduncle-branch system under mechanical vibration and the impact of the vibrating rods on the fruit detachment process in association with this behavior. Fragments of coffee branches containing fruits in the unripe and ripe stages were used in this experiment. These samples were subjected to different frequencies (20, 30, 40, and 50 Hz) and amplitudes (0.002, 0.003, and 0.004 m). Another variable analyzed was the form of vibration transmission to the fruits, with the vibrations being transmitted to the samples with or without the impact of the fiberglass rods. The fruit detachment efficiency increased as the ripening stage progressed from unripe to ripe. A higher detachment efficiency occurred with the increase in vibration frequency and amplitude because of the higher vibrational energy imposed on the fruit. The detachment efficiency was low when the vibration was transmitted without the impact of the rods. Conversely, the vibration in combination with impact achieved a mean detachment efficiency of approximately 90%.Item Occupational exposure to localized vibrations using portable mechanical brush cutter in coffee crop(Editora UFLA, 2019-04) Oliveira Júnior, Geraldo Gomes de; Silva, Adriano Bortolotti da; Cunha, Irlon de Ângelo da; Aparecido, Lucas Eduardo de Oliveira; Sabino, Paulo Henrique de SiqueiraThe use of portable brush cutter may expose workers to localized vibrations, from the transfer of mechanical vibration of the tool to the operator’s hands and arms. With this in mind, the objective in this study was to quantify the levels of occupational vibration transmitted to the hands and arms of the portable brush cutter operators under routine working conditions in the coffee crop. The vibration levels transmitted to the operator’s hands were measured during activity with portable brush cutters. The experimental design was completely randomized (CRD) in a factorial scheme (2 x 2) combined with two types of grip (Circular cable (CC) and double grip handle (DGH) with two types of tip cutting blades (2TB and 3TB). The data acquisition occurred from the use of the vibration meter SV 103, SVANTEK with triaxial accelerometer, installed on each of the worker’s hand at the contact point with the tool. The results demonstrated that the 2.5 ms -2 action level determined by NR 09 and NHO 10 was exceeded under all conditions of the present study. The highest accelerations were quantified in the operation of the brush cutter equipment with CC, reaching the daily exposure limit of 5 ms -2 allowed for an 8-hour of working day. The resulting acceleration of the DGH equipment was on average 37.45% lower than the operation with the CC equipment. The results bring indicatives of occupational advantages in the selection of these types of accessories for brush cutters, in order to mitigate the effects of exposure to HAV in extended use situations.Item Occupational noise level in mechanized and semimecanized harvest of coffee fruits(Editora UFLA, 2018-10) Silva, José Antonio Ramos da; Oliveira Júnior, Geraldo Gomes de; Costa, Carlos Emanuel de Melo; Silva, Adriano Bortolotti da; Gabriel, Camila Pires Cremasco; Putti, Fernando FerrariCoffee cultivation has undergone significant changes, especially with regard to the mechanization process of the various existing operations that were previously carried out manually by the workers. It is observed that the intensification of mechanized activities can expose workers to noise levels capable of compromising their hearing health. In this sense, the objective in the present study was to determine the level of occupational noise in the activities of mechanized and semi- mechanized harvesting of coffee fruits and compare them with the limits of tolerance of the current legislation. The occupational noise level was determined considering the exposure of homogeneous groups, using an integrative meter for personal use, noise dosimeter, electromechanically calibrated and with field calibration. The results demonstrate that the noise levels found are above the limits allowed for an 8-hour working day. The highest observed level was 100.7 dB (A) in the sweeping operation with the blower equipment and the lowest level 89.0 dB (A) in the auxiliary activity of the selected collection equipment Vicon H3000. Harvesting activity with a portable mechanical stripper equipment showed a noise level 4.2% higher compared to harvesting with automotive harvester equipment.Item Characterization of the coffee fruit detachment force in crop subjected to mechanized harvesting(Editora UFLA, 2018-01) Ferreira Júnior, Luiz de Gonzaga; Silva, Fábio Moreira da; Ferreira, Danton Diego; Simão, Sérgio Domingos; Souza, Gabrielly Carvalho de; Ferreira, Lucas KempsIn order to adjust the coffee harvester and to assist in deciding either whether or not to make a second pass of the harvester, fully or selectively, it is necessary to know some crop parameters. The aim of the present study was to evaluate the coffee fruit detachment force in the green and cherry ripeness, under different plant positions and in four evaluation periods, throughout the harvest period between the first and second pass of harvester. The cultivar used was the Catuaí Amarelo IAC 144 aged eight years in spacing 3.8 x 0.9 m. Detachment force was determined by sampling using a portable digital dynamometer. The green ripeness stage showed superior detachment force than the cherry for all evaluation periods. The fruit detachment force for the green and cherry ripeness showed a decreasing behavior during the evaluation period, since the difference between the detachment forces of these fruits increased, thus guiding the type of harvest to be performed. Beyond the fruit detachment force difference, other parameters such as fruit ripening rate and crop load were essential for harvest management. Significant variations were identified in the fruit detachment force positioned in different parts of the coffee tree branches. The results also reinforce the relevance of characterizing the coffee fruit detachment force for harvester adjustments and management of the selective mechanized harvesting.Item Performance of a special tractor as a function of ballasting and front-wheel drive in coffee harvesting(Editora UFLA, 2018-01) Tavares, Tiago de Oliveira; Borba, Matheus Anaan de Paula; Gallo, Luís Alexandre Michelli; Gírio, Lucas Augusto da Silva; Paixão, Carla Segatto Strini; Silva, Rouverson Pereira daOne of the main concerns before agricultural mechanization is the fuel cost from an economic and environmental point of view. In some literature, it has been demonstrated that the adequacy of tractors is directly related to consumption, which may become a strategy to reduce it. However, the studies were performed with conventional tractors, without information on how the special coffee tractors behave to the adequacy. In this respect, the aim of the present study was to evaluate the hourly fuel consumption in six possible adjustments of a special tractor in the operation of mechanized coffee harvesting. A 4x2 FWD tractor was used, with 52.2 kW power and 2400 kg mass, with 40% to the front axle and 60% to the rear to pull a Master Café 2 coffee harvester with 2900 kg mass without load. The treatments consisted of three ballast configurations in the tractor whether or not using auxiliary front-wheel drive (FWD). The adopted mass-power ratios were: 48, 52 and 56 kg kW-1 ; obtained through the quantitative alteration of liquid and solid ballasts of the tractor, respecting the mass distribution between the axles recommended by the tractor manufacturer. The evaluations consisted of monitoring fuel consumption at regular hourly intervals, following the premises of statistical process control. It is concluded that the mass-power ratio of 56 kg kW-1 with driven FWD should be used in order to obtain lower slipping, lower average hourly fuel consumption and higher quality.Item Estudo técnico e econômico de diferentes operações mecanizadas na cafeicultura(Editora UFLA, 2016-01) Cunha, João Paulo Barreto; Silva, Fabio Moreira da; Martins, Felipe Gabriel Lorenzoni; Conceição, Fagner Goes da; Camelo, Lais GuerraCom a adoção da mecanização na cafeicultura, diversas operações, antes manuais, passaram a ser realizadas por máquinas, o que permitiu aumento da capacidade produtiva e redução dos custos. O conhecimento e aplicação de critérios técnicos e econômicos para obtenção dos custos de produção são de suma importância, pois permitem que os custos estimados apresentem solidez e sejam confiáveis, proporcionando melhor competitividade ao produtor. Objetivando-se, realizar uma análise técnica e econômica de diferentes operações mecanizadas na cafeicultura, o trabalho foi conduzido no município de Alfenas- MG, onde foram analisados tempos necessários para a realização de diversas operações dos conjuntos mecanizados e também os seus respectivos custos fixos e variáveis. A análise de cada conjunto foi realizada pelo produto de horas totais despendidas em cada operação, em função dos custos de produção. Com base nos dados obtidos, os tempos de reparos e manutenção afetam diretamente a disponibilidade mecânica dos conjuntos mecanizados. A depreciação e os custos com combustível são os principais componentes que compõem os custos fixos e variáveis, respectivamente. As operações de recolhimento e varrição do café de chão são as operações com a menor viabilidade técnica e econômica, apresentando custos improdutivos superiores aos custos produtivos.Item Eficiência de campo em diferentes operações mecanizadas na cafeicultura(Editora UFLA, 2016-01) Cunha, João Paulo Barreto; Silva, Fabio Moreira da; Dias, Rodrigo Elias Batista AlmeidaO café é uma cultura de destaque no Brasil, tanto que, nos últimos anos, passou por grandes modificações, com a utilização intensa da mecanização, que se tornou uma alternativa viável para grande parte dos produtores, possibilitando aumento da capacidade operacional e redução dos custos de produção. Atualmente, em áreas totalmente aptas à mecanização, todas as operações durante o ciclo da cultura são realizadas, mecanicamente, por diferentes máquinas e implementos. Conduziu-se, o presente estudo, no município de Alfenas-MG, para determinar a capacidade de trabalho e a eficiência de campo de máquinas utilizadas nas diferentes operações da lavoura cafeeira. Os dados de desempenho obtidos foram tratados estatisticamente pela correlação de Pearson (p), o que permitiu determinar a influência da velocidade operacional e comprimento médio das entrelinhas, nos parâmetros de desempenho. Com base nos resultados, os parâmetros de desempenho operacional, capacidade de campo efetiva e tempo demandado apresentaram alta correlação com a velocidade operacional dos conjuntos mecanizados. As operações de preparo de covas, varrição e recolhimento apresentaram os menores resultados de eficiência de campo, enquanto as demais operações avaliadas apresentaram valores acima de 70%, considerados aceitáveis.
- «
- 1 (current)
- 2
- 3
- »