Temperature control in a solar collector field using Filtered Dynamic Matrix Control.

This paper presents the output temperature control of a solar collector field of a desalinization plant using the Filtered Dynamic Matrix Control (FDMC). The FDMC is a modified controller based on the Dynamic Matrix Control (DMC), a predictive control strategy widely used in industry. In the FDMC, a filter is used in the prediction error, which allows the modification of the robustness and disturbance rejection characteristics of the original algorithm. The implementation and tuning of the FDMC are simple and maintain the advantages of DMC. Several simulation results using a validated model of the solar plant are presented considering different scenarios. The results are also compared to nonlinear control techniques, showing that FDMC, if properly tuned, can yield similar results to more complex control algorithms.

Análise da prevalência do quarto canal de primeiros e segundos molares superiores permanentes humanos: avaliação clínica versus avaliação microscópica / Analysis of the prevalence of the fourth canal in first and second molars permanent humans: clinical evaluation versus microscopic evaluation

O objetivo deste estudo foi analisar a prevalência do quarto canal em primeiros e segundos molares superiores humanos e identificar onde esses canais uniam-se. Foram avaliados 89 dentes primeiros e segundos molares superiores humanos. Primeiramente, foi realizada uma análise clínica convencional em todos os dentes, procurando identificar o 4O canal, chamado MP. Em seguida, foi realizada uma nova análise desses dentes com o auxílio do Microscópio Operatório (MO), comparando os resultados. A última etapa deste trabalho foi identificar, através de radiografias, onde os canais da raiz mésio vestibular uniam-se. Observou-se que no exame clínico o 4O canal estava presente em 47,2% (42) dos dentes examinados, já no exame microscópico houve um considerável aumento, fazendo com que 65,1% (58) dos dentes examinados apresentassem o canal MP. Em 43,2% dos dentes analisados, os canais da raiz mésio vestibular estavam independentes. O MO é um instrumento muito importante para o domínio da anatomia interna dos dentes, aumentando de forma significante a quantidade de dentes em que o canal MP foi encontrado, em relação à análise clínica

The objective of this study was to analyze the prevalence of the mesiopalatine canal present in first and second maxillary permanent molars humans and identify where the fusion of the mesiobuccal root canals occur. Eighty-nine first and second maxillary permanent human molars were selected and evaluated clinically in order to determine the location of the mesiopalatine canal. After the samples were observed under a light microscope 40X magnification with the same purpose. Finally, X-rays were taken from those teeth to determine the canal pathway. In the clinical examination, the mesiopalatine canal was present in 47.2% (42) of the teeth examined, in the microscopic examination there was a considerable increase, making 65.1% (58) of the teeth examined has the canal orifice. In 43.2% of teeth examined mesiopalatine canals were independent. Operation microscope is a very important arsenal to diagnosis of the internal anatomy of teeth, increasing significantly the number of teeth in the canal orifice was found in relation to clinical analysis