Navegando por Autor "Rocha, Ronicely Pereira"
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Item Avaliação da cinética de secagem de carqueja(Engenharia na Agricultura, 2010-05-11) Radünz, Lauri Lourenço; Amaral, Antônio Sergio do; Mossi, Altemir José; Melo, Evandro de Castro; Rocha, Ronicely PereiraEste trabalho teve por objetivo estudar a cinética de secagem de carqueja, submetida a diferentes temperaturas do ar e posterior ajuste dos dados experimentais a diferentes modelos matemáticos. Para condução do experimento de secagem foram utilizados seis secadores de bandejas, empregando-se as temperaturas de 40, 50, 60, 70, 80 e 90 ºC. Foi utilizado o delineamento experimental de blocos ao acaso, com três repetições, colocando-se 800 g de folhas frescas em cada bandeja. Para o ajuste dos modelos matemáticos aos dados experimentais, realizou-se análise de regressão não linear, pelo método Quasi-Newton, sendo os valores dos parâmetros dos modelos estimados em função da temperatura do ar de secagem. Os resultados mostraram que o modelo de Midilli et al. apresentou ajuste adequado aos dados experimentais, para toda a faixa de temperatura estudada (de 40 a 90 ºC), e o modelo de Page apresentou ajuste adequado aos dados experimentais apenas para a faixa de temperatura de 60 a 90 ºC.Item Controle da temperatura e velocidade do ar de secagem em um secador de plantas medicinais(Engenharia na Agricultura, 2010-06-06) Prates, Mauro de Oliveira; Pizziolo, Tarcísio de Assunção; Melo, Evandro de Castro; Rocha, Ronicely Pereira; Nicácio, José VitorEste trabalho teve como objetivo a implementação de um sistema de controle de temperatura e velocidade do ar, em um secador de plantas medicinais, utilizando-se microcontrolador PIC16F877A. A velocidade do ar foi monitorada com anemômetro de conchas e o seu controle realizado com um inversor de frequência. A temperatura foi medida pelo sensor LM35 e o seu controle foi realizado utilizando-se um triac. com um microcontrolador realizaram-se ações de controle PID, que determinavam a largura de pulso de um sinal PWM, que acionava o inversor de frequência e, também, o triac. Foi realizada a comparação entre dois métodos de controle de velocidade: manual e automático. Verificou-se redução de 63 % no consumo de energia elétrica quando foi utilizado o método automático.Item Determination of moisture content from guaco with microwave oven(Engenharia na Agricultura, 2010-05-10) Rocha, Ronicely Pereira; Melo, Evandro de Castro; Radunz, Lauri LourençoThis study was done to develop a quick method to determine moisture content of guaco’s leaves (Mikania glomerata Sprengel), to assist in research on medicinal and aromatic plants. Guaco’s leaves with moisture content between 7 to 82 % w.b. were exposed in a microwave oven set at 340, 570, 660 or 880 W, for 3, 4 or 5 minutes. In order to determine the regression equations, the results of moisture content determined by the microwave method were correlated with the values determined with standard gravimetric method. The most appropriate power and exposure time combination was founfd to be 660 W for 3 minutes. The microwave oven appears to be a viable alternative for determination of moisture content of guaco’s leaves.Item Efeito da temperatura do ar de secagem sobre a qualidade do óleo essencial de Mikania glomerata(Effect of drying air temperature on the quality of essential oil from Mikania glomerata, 2013-12-31) Rocha, Ronicely Pereira; Melo, Evandro de Castro; Barbosa, Luiz Cláudio de Almeida; Radunz, Lauri LourençoThis study aimed to evaluate the influence of drying air temperature on the content of essential oil extracted from guaco. The drying tests were performed in an experimental fixed-bed dryer, which contains 4 perforated trays with upward air flow. Treatments consisted of five temperatures for the drying air (ambient air and air heated to 40, 55, 70 and 85oC), with three repetition, using 850 g of fresh guaco leaves. Guaco leaves were dried until reaching a final moisture content of approximately 10% w.b. The drying air velocity was 0.5 m s -1 . Essential oil extraction was performed by hydrodestilation, using Clevenger equipment. Results of the essential oil content showed that the drying air temperatures from 55 to 85oC did not statistically influence the essential oil content. The chromatographic profile of the essential oil presented changes as a function of the drying treatment when compared with the in natura plant (control).Item Influence of drying air temperature on the chemical composition of the essential oil of melaleuca(Engenharia na Agricultura, 2011-10-25) Lemos, Diana Rodrigues Herinque; Melo, Evandro de Castro; Rocha, Ronicely Pereira; Barbosa, Luiz Cláudio de Almeida; Pinheiro, Antonio LelisThis study was done to evaluate the influence of drying air temperature on the chemical composition of the essential oil of Melaleuca alternifólia Cheel. Three samples were taken at random from each treatment which were analyzed still fresh, determining the moisture content and chemical composition of the essential oil.The plants were chopped and placed in a fixed-bed dryer and dried with air temperature of 40, 50, 60, 70 and 80 °C. The identification of compounds was done using gas chromatography coupled to mass spectrometry. The major components of essential oil of melaleuca subjected to drying air temperatures of 40, 50, 60, 70 and 80 ° C were within the ISO Standard 4730, which classifies plant as medicinal or not.There was an increase in the levels of terpinen-4-ol and α-terpineol and decrease of α-pinene compared to the control.Item Study of essential oil from guaco leaves submitted to different drying air temperature(Engenharia na Agricultura, 2010-01-20) Radünz, Lauri Lourenço; Melo, Evandro de Castro; Rocha, Ronicely Pereira; Berbert, Pedro Amorim; Gracia, Luiz Manuel NavasThis study aimed to evaluate the influence of drying air temperature on the content and chemical composition of essential oil extracted from guaco. Six drying treatments were used: ambient air and heated air at 40, 50, 60, 70 and 80o C. The essential oil contents, after drying, were compared with the values obtained from the fresh plant (control). The essential oil extraction was performed by hydrodistillation. From the results obtained, it could be concluded that the temperature of the drying air at 50o C provided the best results for the extraction of essential oil in guaco leaves, despite the fact that the chromatographic profile of the oil showed alterations in comparison with that obtained from the fresh plant.