Engenharia Agrícola

URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/10363

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Resultados da Pesquisa

Agora exibindo 1 - 6 de 6
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    Vibration Transmissibility of the Coffee Fruit-Peduncle System: a Forced Vibration Study of High Frequency Aiming Mechanical Harvesting
    (Associação Brasileira de Engenharia Agrícola, 2023-01-30) Villibor, Geice P.; Santos, Fábio L.; Queiroz, Daniel M.; Khoury Junior, Joseph K; Pinto, Francisco A. C.
    Semi-mechanized and mechanized harvesting use machines that promote the transference of vibrational energy and impact to achieve the detachment of coffee fruits. The aim of this study was to evaluate the vibration transmissibility in coffee fruit-peduncle systems, using high-speed cameras, submitted to high frequency harmonic excitation in different combinations between frequency and amplitude of vibration, identifying working ranges suitable to perform selective harvesting. Vibration transmissibility was determined for the coffee fruit-peduncle systems, for the maturation stages unripe and ripe that were subjected to a sinusoidal harmonic displacement, in which the input parameters were frequency (35, 45 and 55 Hz) and peak-to-peak amplitude (3.5, 5.0 and 6.5 mm). An experiment was used to study the effect of frequency and amplitude on vibration transmissibility in a completely randomized design in a factorial scheme 3 x 3 x 2, with three replications. The frequency of 35 Hz, associated with the amplitudes 3.5-6.5 mm, was the one that most influenced the results of vibration transmissibility. For the frequency of 55 Hz and amplitude of 6.5 mm, in the ripe maturation stage, the vibration transmissibility was higher than 1.0, which could be a suitable combination for selective coffee harvesting.
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    Mobile Application for Adjusting Air-Bast Sprayers in Coffee Plantation
    (Associação Brasileira de Engenharia Agrícola, 2022-09-13) Cunha, João P. A. R. da; Alves, Thales C.; Penha, Rafael S. A.
    Mobile application development advances, particularly for smartphones and tablets, have allowed farmers to make decisions more assertively in their agrobusiness management. This article addresses the development and evaluation of an app aimed at people who deal with the pesticide application technology in coffee farming, more specifically, adjustment and calibration of sprayers. This mobile app provides the main data necessary for a correct calibration of air-blast sprayers to apply pesticides in coffee planting. Its functionalities include calculation of the application rate for each situation (L ha-1) based on data obtained in the field, such as canopy volume. The app, called SprayCafé, was developed for the Android platform using the Java programming language in the integrated development environment Android Studio. After the development, the application was evaluated, based on a questionnaire answered by 139 users, who ranked the following requirements: ease of use, loading time, adequacy of screen resolution, data relevance, sequence of information, and applicability, among others. The system proved to be simple and robust; it was thus assessed as adequate to the field and to be of great value for coffee planting, especially because it allows safer and more adequate pesticide application. The graphical user interface is interactive and easy to use.
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    Spatial variability of noise generated by a self-propelled coffee harvester in an open area
    (Associação Brasileira de Engenharia Agrícola, 2022-07-31) Silva, José A. R. da; Manzione, Rodrigo L.; Oliveira Junior, Geraldo G. de; Silva, Adriano B. da; Putti, Fernando F.
    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.
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    Mobile application for adjusting air-blast sprayers in coffee plantation
    (Associação Brasileira de Engenharia Agrícola, 2022-09-13) Cunha, João P. A. R. da; Alves, Thales C.; Penha, Rafael S. A.
    Mobile application development advances, particularly for smartphones and tablets, have allowed farmers to make decisions more assertively in their agrobusiness management. This article addresses the development and evaluation of an app aimed at people who deal with the pesticide application technology in coffee farming, more specifically, adjustment and calibration of sprayers. This mobile app provides the main data necessary for a correct calibration of air-blast sprayers to apply pesticides in coffee planting. Its functionalities include calculation of the application rate for each situation (L ha-1) based on data obtained in the field, such as canopy volume. The app, called SprayCafé, was developed for the Android platform using the Java programming language in the integrated development environment Android Studio. After the development, the application was evaluated, based on a questionnaire answered by 139 users, who ranked the following requirements: ease of use, loading time, adequacy of screen resolution, data relevance, sequence of information, and applicability, among others. The system proved to be simple and robust; it was thus assessed as adequate to the field and to be of great value for coffee planting, especially because it allows safer and more adequate pesticide application. The graphical user interface is interactive and easy to use.
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    Photovoltaic plant to supply energy for an electric coffee dryer - energy costs and compensation
    (Associação Brasileira de Engenharia Agrícola, 2023-11) Konopatzki, Evandro A.; Oliveira, Cristiane L. de; Marangoni, Filipe; Edwiges, Thiago; Christ, Divair
    In this work, we sought to minimize electricity costs in the coffee bean drying process by carrying out the theoretical sizing of the economic viability of the Photovoltaic Power plant (PVP) ongrid used to supply a Dryer Unit (DU). The methodology consisted of adequate sizing of a PVP generation plant to promote the electric energy balance. It used economic indicators such as internal rate of return, discounted payback, and net present value. Two scenarios were considered: a pessimistic with DU use on-peak period; and an optimistic with full use of the DU during the off-peak period. It was considered local electricity tariff values, and the results indicated the economic feasibility for the PVP installation also the feasibility of the dryer use in both scenarios, there are no restrictions on operating hours. It can be concluded that it is essential to understand the Brazilian electricity bill legislation because only in this way is it possible to properly develop the on-grid photovoltaic power plant projects. The technical and economic parameters are inseparable and indicated that the electricity tariff should not exceed US$ 0.22 (kWh) -1 to ensure the photovoltaic power plants installation viability to supply DUs that remain in operation during on-peak periods.
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    Coffee dryer with dehydrated air: a technical and economic viability analysis
    (Associação Brasileira de Engenharia Agrícola, 2022-08-22) Konopatzki, Evandro A.; Christ, Divair; Coelho, Silvia R. M.; Demito, Angélica; Ivan, Werncke; Camicia, Rafaela G. da M.
    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.