Utilização da radiação infravermelha na secagem de amostras de banana / Use of infrared radiation in drying banana samples

Este trabalho teve como objetivo secar amostras de 50 gramas de banana prata cortada em fatias com espessura de 5 mm, utilizando-se fontes de radiação infravermelha, a partir de simulação computacional e construção de protótipo para realização do experimento. A distribuição do campo eletromagnético foi obtida por meio do software CST Studio Suíte® e os resultados foram utilizados para construção do protótipo. As amostras foram submetidas à radiação por infravermelho durante o período de 70 minutos. As lâmpadas foram desligadas a cada 10 minutos para a medição da massa das amostras, verificando-se que houve estabilização da massa a partir de 50 minutos. As amostras em cada período foram submetidas à análise de umidade. Obteve-se uma redução da umidade inicial da banana prata in natura de 69,9 g/100g para 21,2 g/100 g, sendo este valor compatível com o normalmente adotado para a comercialização da banana desidratada

Projeto e implementação de sistemas de controle distribuído em redes de computadores

Exportado OPUSMade available in DSpace on 2019-08-12T03:32:33Z (GMT). No. of bitstreams: 1 euler_cunha_martins.pdf: 4086067 bytes, checksum: 59a3ed807a81b148da380bbf3c679f65 (MD5) Previous issue date: 3Este trabalho apresenta as principais características dos sistemas de controle via redes e suas particularidades em relação aos sistemas clássicos de controle. Os efeitos dos atrasos de tempo provocados pelos enlaces de rede que interligam os elementos da malha de controle são analisados. Foram realizados testes em uma planta real de primeira ordem (um circuito RC) e um estudo detalhado da influência individual e combinada dos atrasos introduzidos pela rede (sensor/controlador e controlador/atuador) é apresentado. Os testes foram realizados em uma plataforma didática, em que os enlaces de redes são substituídos por buffers, permitindo o total controle sobre estes eventos de tempo. Para análise do sistema em malha fechada foi utilizado um controlador PI projetado pelo método da Síntese Direta e implementado no formato de equações de diferenças, utilizando as transformações Z e delta. É implementado um algoritmo preliminar de controle com compensação explícita do sinal de controle. Esse algoritmo utiliza um estimador para a saída da planta e um compensador para variações na ação de controle. A estratégia foi implementada em um sistema real visando a melhoria do desempenho do sistema em teste. Os resultados simulados e experimentais são apresentados. Um algoritmo de controle, do qual a Internet faz parte, é apresentado. Esse algoritmo possui uma rotina de sincronização entre as máquinas local e remota, um estimador para a saída da planta baseado na transformada delta, um estimador on-line de parâmetros da planta, um controlador remoto, um controlador local e um sistema de chaveamento entre os controladores remoto e local. O algoritmo proposto é implementado em um sistema NCS real, desenvolvido neste trabalho, denominado NCS-CMUF. Inicialmente, o sistema é usado para o controle de um circuito RC (planta de primeira ordem) e, posteriormente, uma planta real: o Sistema de Tanques Interativos. Alguns resultados simulados e experimentais obtidos usando o algoritmo proposto, bem como a análise de estabilidade (em condições particulares), são apresentados.This work presents the main characteristics of the networked control systems and their particularities compared with the classical control systems. The effects of the delays, caused by the inherent network communication process between the various interconnected elements of the control loop, are analyzed. Tests in a real plant, of first order (an RC circuit), have been carried out and a detailed study of the individual and the combined influence of the delays introduced by the network (sensor/controller and controller/actuator) are considered. The tests have been accomplished in didactic platform, where the network has been replaced by buffers to allow full control of the events in time. For analysis of the closed-loop, a PI-controller, designed by the well-known Direct Synthesis method, has been used and implemented in the form of differences equations, whose coefficients have been derived from the Z and delta transforms. A preliminary control algorithm with explicit compensation of the control signal is implemented. This control algorithm uses an estimation of the plant output to compensate for variations in the control action. The strategy has been implemented in a real system aiming at improving the performance of the system under test. Simulated and experimental results are presented. A control algorithm for NCSs, of which the Internet is part, is presented. This algorithm possesses a synchronization routine between the local and remote units, an estimator for the plant output based on delta transform, an on-line parameters estimator, a remote controller, a local controller and an automatic switching scheme between the remote and local controllers. The proposed algorithm is implemented in a real NCS system, developed for this work, named NCS-CMUF. Initially, the system is used to control an RC circuit (the first order plant) and, later, a real plant: the Interacting Tank System. Some simulated and experimental results obtained using the proposed algorithm, as well as an analysis of stability (under particular conditions), are presented

Comparação do orégano (Origanum vulgare) seco por diferentes metodologias: secagem em estufa e por irradiação na região do infravermelho com e sem pré-tratamento por branqueamento

O orégano (Origanum vulgare) uma erva utilizada mundialmente na culinária e na medicina popular, apresenta vários fitofármacos das classes dos compostos polifenólicos. Sua comercialização é realizada, principalmente na forma desidratada, pois a desidratação além de promover a concentração dos metabólitos no material vegetal, favorece sua conservação por diminuir a ocorrência de reações enzimáticas e a proliferação microbiana. Porém, o aquecimento promovido durante a desidratação pode afetar o perfil químico do material. Com o objetivo de comparar o perfil químico do orégano fresco com os perfis químicos após a secagem em estufa convencional e secagem por irradiações no infravermelho de amostras com e sem tratamento prévio por processo de branqueamento, o presente trabalho foi realizado. As análises dos perfis químicos dos extratos realizadas por ESI-MS indicaram que as amostras secas por irradiação no IV apresentaram os mesmos 12 compostos fenólicos presentes nas folhas frescas, enquanto nas folhas secas em estufa, foi possível identificar apenas 8 dos compostos fenólicos identificados nos demais extratos. Observou-se ainda que processo de branqueamento favoreceu a fixação da cor, promoveu a redução do tempo de secagem e aumentou a eficiência da redução do teor de água. Foi possível concluir que a secagem por irradiação IV é eficiente e que o branqueamento favorece ainda mais este processo

Effect of Ischemic Postconditioning and Atorvastatin in the Prevention of Remote Lung Reperfusion Injury

Abstract Objective: The aim of the present study was to evaluate the ability of ischemic postconditioning, atorvastatin and both associated to prevent or minimize reperfusion injury in the lung of rats subjected to ischemia and reperfusion by abdominal aortic clamping. Methods: We used 41 Wistar norvegic rats, which were distributed into 5 groups: ischemia and reperfusion (I/R), ischemic postcondictioning (IPC), postconditioning + atorvastatin (IPC+A), atorvastatin (A) and SHAM. It was performed a medium laparotomy, dissection and isolation of the infra-renal abdominal aorta; except for the SHAM group, all the others were submitted to the aortic clamping for 70 minutes (ischemia) and posterior clamp removal (reperfusion, 70 minutes). In the IPC and IPC+A groups, postconditioning was performed between the ischemia and reperfusion phases by four cycles of reperfusion and ischemia lasting 30 seconds each. In the IPC+A and A groups, preceding the surgical procedure, administration of 3.4 mg/day of atorvastatin was performed for seven days by gavage. After the surgical procedure, the right caudal lobe was removed from the lung for histological study, using tissue injury score ranging from grade 1 (normal tissue) to grade 4 (intense lesion). Results: The mean lung injury was 3.6 in the I/R group, 1.6 in the IPC group, 1.2 in the IPC+A group, 1.2 in the A group, and 1 in the SHAM group (P<0.01). Conclusion: Ischemic postconditioning and atorvastatin were able to minimize lung reperfusion injury, alone or in combination

Evaluation of the Effects of Atorvastatin and Ischemic Postconditioning Preventing on the Ischemia and Reperfusion Injury: Experimental Study in Rats

Abstract Introduction: Reperfusion injury leads to systemic morphological and functional pathological alterations. Some techniques are already estabilished to attenuate the damage induced by reperfusion. Ischemic preconditioning is one of the standard procedures. In the last 20 years, several experimental trials demonstrated that the ischemic postconditioning presents similar effectiveness. Recently experimental trials demonstrated that statins could be used as pharmacological preconditioning. Methods: 41 Wistar rats (Rattus norvegicus albinus) were distributed in 5 groups: Ischemia and Reperfusion (A), Ischemic Postconditioning (B), Statin (C), Ischemic Postconditioning + Statins (D) and SHAM (E). After euthanasia, lungs, liver, kidneys and ileum were resected and submitted to histopathological analysis. Results: The average of lung parenchymal injury was A=3.6, B=1.6, C=1.2, D=1.2, E=1 (P=0.0029). The average of liver parenchymal injury was A=3, B=1.5, C=1.2, D=1.2, E = 0 (P<0.0001). The average of renal parenchymal injury was A=4, B=2.44, C=1.22, D=1.11, E=1 (P<0.0001). The average of intestinal parenchymal injury was A=2, B=0.66, C=0, D=0, E=0 (P=0.0006). The results were submitted to statistics applying Kruskal-Wallis test, estabilishing level of significance P<0.05. Conclusion: Groups submitted to ischemic postconditioning, to pre-treatment with statins and both methods associated demonstrated less remote reperfusion injuries, compared to the group submitted to ischemia and reperfusion without protection

Evaluation of the Effects of Atorvastatin and Ischemic Postconditioning Preventing on the Ischemia and Reperfusion Injury: Experimental Study in Rats

<div><p>Abstract Introduction: Reperfusion injury leads to systemic morphological and functional pathological alterations. Some techniques are already estabilished to attenuate the damage induced by reperfusion. Ischemic preconditioning is one of the standard procedures. In the last 20 years, several experimental trials demonstrated that the ischemic postconditioning presents similar effectiveness. Recently experimental trials demonstrated that statins could be used as pharmacological preconditioning. Methods: 41 Wistar rats (Rattus norvegicus albinus) were distributed in 5 groups: Ischemia and Reperfusion (A), Ischemic Postconditioning (B), Statin (C), Ischemic Postconditioning + Statins (D) and SHAM (E). After euthanasia, lungs, liver, kidneys and ileum were resected and submitted to histopathological analysis. Results: The average of lung parenchymal injury was A=3.6, B=1.6, C=1.2, D=1.2, E=1 (P=0.0029). The average of liver parenchymal injury was A=3, B=1.5, C=1.2, D=1.2, E = 0 (P<0.0001). The average of renal parenchymal injury was A=4, B=2.44, C=1.22, D=1.11, E=1 (P<0.0001). The average of intestinal parenchymal injury was A=2, B=0.66, C=0, D=0, E=0 (P=0.0006). The results were submitted to statistics applying Kruskal-Wallis test, estabilishing level of significance P<0.05. Conclusion: Groups submitted to ischemic postconditioning, to pre-treatment with statins and both methods associated demonstrated less remote reperfusion injuries, compared to the group submitted to ischemia and reperfusion without protection.</p></div

Effect of Ischemic Postconditioning and Atorvastatin in the Prevention of Remote Lung Reperfusion Injury

<div><p>Abstract Objective: The aim of the present study was to evaluate the ability of ischemic postconditioning, atorvastatin and both associated to prevent or minimize reperfusion injury in the lung of rats subjected to ischemia and reperfusion by abdominal aortic clamping. Methods: We used 41 Wistar norvegic rats, which were distributed into 5 groups: ischemia and reperfusion (I/R), ischemic postcondictioning (IPC), postconditioning + atorvastatin (IPC+A), atorvastatin (A) and SHAM. It was performed a medium laparotomy, dissection and isolation of the infra-renal abdominal aorta; except for the SHAM group, all the others were submitted to the aortic clamping for 70 minutes (ischemia) and posterior clamp removal (reperfusion, 70 minutes). In the IPC and IPC+A groups, postconditioning was performed between the ischemia and reperfusion phases by four cycles of reperfusion and ischemia lasting 30 seconds each. In the IPC+A and A groups, preceding the surgical procedure, administration of 3.4 mg/day of atorvastatin was performed for seven days by gavage. After the surgical procedure, the right caudal lobe was removed from the lung for histological study, using tissue injury score ranging from grade 1 (normal tissue) to grade 4 (intense lesion). Results: The mean lung injury was 3.6 in the I/R group, 1.6 in the IPC group, 1.2 in the IPC+A group, 1.2 in the A group, and 1 in the SHAM group (P<0.01). Conclusion: Ischemic postconditioning and atorvastatin were able to minimize lung reperfusion injury, alone or in combination.</p></div