Online Intelligent Controllers for an Enzyme Recovery Plant: Design Methodology and Performance

This paper focuses on the development of intelligent controllers for use in a process of enzyme recovery from pineapple rind. The proteolytic enzyme bromelain (EC 3.4.22.4) is precipitated with alcohol at low temperature in a fed-batch jacketed tank. Temperature control is crucial to avoid irreversible protein denaturation. Fuzzy or neural controllers offer a way of implementing solutions that cover dynamic and nonlinear processes. The design methodology and a comparative study on the performance of fuzzy-PI, neurofuzzy, and neural network intelligent controllers are presented. To tune the fuzzy PI Mamdani controller, various universes of discourse, rule bases, and membership function support sets were tested. A neurofuzzy inference system (ANFIS), based on Takagi-Sugeno rules, and a model predictive controller, based on neural modeling, were developed and tested as well. Using a Fieldbus network architecture, a coolant variable speed pump was driven by the controllers. The experimental results show the effectiveness of fuzzy controllers in comparison to the neural predictive control. The fuzzy PI controller exhibited a reduced error parameter (ITAE), lower power consumption, and better recovery of enzyme activity

Detection and on-line prediction of leak magnitude in a gas pipeline using an acoustic method and neural network data processing

Considering the importance of monitoring pipeline systems, this work presents the development of a technique to detect gas leakage in pipelines, based on an acoustic method, and on-line prediction of leak magnitude using artificial neural networks. On-line audible noises generated by leakage were obtained with a microphone installed in a 60 m long pipeline. The sound noises were decomposed into sounds of different frequencies: 1 kHz, 5 kHz and 9 kHz. The dynamics of these noises in time were used as input to the neural model in order to determine the occurrence and the leak magnitude. The results indicated the great potential of the technique and of the developed neural network models. For all on-line tests, the models showed 100% accuracy in leak detection, except for a small orifice (1 mm) under 4 kgf/cm² of nominal pressure. Similarly, the neural network models could adequately predict the magnitude of the leakages.14515

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This paper focuses on the development of intelligent controllers for use in a process of enzyme recovery from pineapple rind. The proteolytic enzyme bromelain (EC 3.4.22.4) is precipitated with alcohol at low temperature in a fed-batch jacketed tank. Temperature control is crucial to avoid irreversible protein denaturation. Fuzzy or neural controllers offer a way of implementing solutions that cover dynamic and nonlinear processes. The design methodology and a comparative study on the performance of fuzzy-PI, neurofuzzy, and neural network intelligent controllers are presented. To tune the fuzzy PI Mamdani controller, various universes of discourse, rule bases, and membership function support sets were tested. A neurofuzzy inference system (ANFIS), based on Takagi-Sugeno rules, and a model predictive controller, based on neural modeling, were developed and tested as well. Using a Fieldbus network architecture, a coolant variable speed pump was driven by the controllers. The experimental results show the effectiveness of fuzzy controllers in comparison to the neural predictive control. The fuzzy PI controller exhibited a reduced error parameter (ITAE), lower power consumption, and better recovery of enzyme activity

Qualidade do café arábica em diferentes altitudes no Espírito Santo.

Este trabalho teve como objetivo avaliar a influência de diferentes altitudes na qualidade do café arabica, avaliada pela análise sensorial. Para tanto, foram avaliados grãos de três cultivares de café arábica colhidos em três ambientes com altitudes diferentes, ou seja, a 700 m, 950 m e 1100 m, nos municípios de Venda Nova do Imigrante, Domingos Martins e Santa Maria do Jetiba, respectivamente. Os cafés foram secos em terreiro suspenso coberto até que alcançassem 12% de umidade. A classificação sensorial foi realizada por um provador especializado, sem prévio conhecimento das amostras. Verificou-se que cafés cultivados em maiores altitudes originaram melhores bebidas. Não houve diferença significativa entre as cultivares Rubi, Catuai Vermelho IAC 44 e Catuai Vermelho IAC 81 para a qualidade da bebida

Pitture antiche nella Galleria fiorentina: alcune testimonianze

Dall'analisi delle carte amministrative e della gestione della Galleria fiorentina nel periodo lorenese, siamo in grado di recuperare l'interesse del museo di Stato per la pittura antica, con rare testimonianze, significative comuqnue del livello di fruizione di questa tipologia del patrimonio in rapporto anche col mercato locale ed il collezionismo privato

Le pietre meravigliose

La passione per le pietre incise divenne nel Settecento un vero e proprio genere collezionistico che qualific\uf2 gli studioli e gli scrigni di importanti famiglie principesche e della nascente borghesia illuminata. Il collezionismo glittico coinvolse istanze di erudizione, ma spesso accompagn\uf2 interessi diversi strettamente legati alla funzione del monile, al suo significato, alle caratteristiche delle pietre