Cinética de secagem de folhas de erva baleeira (Cordia verbenacea DC. ) / Drying kinetics of Cordia verbenacea DC. leaves

O objetivo do presente trabalho foi avaliar a cinética de secagem das folhas de erva baleeira (Cordia verbenacea DC.) bem como ajustar diferentes modelos matemáticos aos valores experimentais de razão de umidade. As folhas de erva baleeira foram colhidas com teor de água inicial de 75% b.u., sendo submetidas à secagem sob condições controladas de temperatura (40, 50, 60 e 70°C), até o teor de água aproximado de 10% b.u.. Aos dados experimentais foram ajustados oito modelos matemáticos citados na literatura específica e utilizados para a representação do processo de secagem de produtos agrícolas. Com base nos resultados obtidos pôde-se concluir que o modelo de Midilli é o que melhor representa a cinética de secagem das folhas de erva baleeira. O aumento da temperatura do ar de secagem promoveu maior taxa de remoção de água do produto. O coeficiente de difusão efetivo aumenta com a elevação da temperatura, sendo que sua relação com a temperatura de secagem pode ser descrita pela equação de Arrhenius. A energia de ativação para a difusão líquida durante a secagem das folhas de erva baleeira foi de 62,89 kJ mol-1 .

The objective of the present work was to evaluate the drying kinetics of Cordia verbanacea DC. leaves, as well to fit different mathematical models to the experimental data of the moisture ratio. The Cordia verbanacea Dc. leaves wers harvested with initial moisture content of approximately 75% w.b. and submitted to the drying process under controlled conditions of temperature (40, 50 60 and 70ºC), until the approximate moisture content of 10% w.b. Eight mathematical models mentioned or the specific literature were fitted to the experimental data and used to predict the drying process of the agricultural products. Based on the results obtained,swe have concluded that the Midilli model was the one that best represents the drying kinetics of Cordia verbanacea leaves. The temperature increase of the drying air promotes higher removal rate of water from the product. The effective diffusion coefficient increases with temperature elevation,tand its relationship with the drying temperature can be described through the Arrhenius equation, which presents activation energy of 62.89 kJ mol-1 for the liquid diffusion during the drying of the Cordia verbanacea DC. leaves.

[Pediatric fiber bronchoscopy. Apropos 55 children examined]. / Fibrobroncoscopia pediátrica. A propósito de 55 niños explorados.

We present our experience with 55 children in which we performed flexible fiberoptic bronchoscopy (FFB) using an Olympus BF3C20 instrument and by using sedation and local anaesthesia or laryngeal mask airway. Indications for performing this procedure were stridor, opportunist or recurrent pneumonia, persistent atelectasis, a suspected foreign body, confirmation of endobronchial tuberculosis and evaluation of tracheostomy. In 70% of the cases, the diagnosis was made by the FFB and 14 cases were normal. One child with severe hypoxia presented respiratory arrest and need intubation. Our results suggest that FFB is safe, has advantages over rigid bronchoscopy, avoids general anaesthetic and with laryngeal mask airway is possible to perform in patients of every age.