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Campo Grande, Brazil

The response surface methodology (RSM) is a collection of statistical and mathematical techniques for developing, improving and optimizing processes. In this study, RSM technique was applied to the investigation of the mechanical behavior of different PP/EPDM/SRT ternary mixtures. After appropriate processing in a co-rotating twin extruder and injection molding, the mechanical properties, such as tensile strength and impact strength, were determined and used as response variables. Scanning electron microscopy (SEM) was used for investigating the morphology of the different blends and to interpret the results. With specific statistical tools, a minimum number of experiments allowed the response surface model to be developed and the concentrations of the components to be optimized according to the mechanical performance. High values of impact strength were reached (>80 J.m -1) when the PP/EPDM/SRT mixture had a EPDM/SRT ratio of around 25%. Source

Dos Santos C.K.,Institute Pesquisas Da Marinha IPqM | Espindola R.P.,Centro Universitario da Zona Oeste | Evsukoff A.G.,Federal University of Rio de Janeiro
IEEE Latin America Transactions | Year: 2015

This paper investigates the use of three external feedback connections in the development of new recurrent fuzzy models for prediction of nonlinear dynamic systems. These models are formulated by state space equations. The state transition function is a TSK recurrent fuzzy system with an external feedback connection and adaptive delayed operators, and the output function is a polynomial function of the states. The identification of the model's parameters is carried out by a canonical differential evolution algorithm. The model performance was evaluated in benchmark problems found in the literature and the results demonstrated that the aiding of external feedbacks enhanced the recurrent fuzzy system quality, yielding models with good performance. © 2003-2012 IEEE. Source

Souza A.R.,Estacio de Sa University | Cardoso M.E.O.,Estacio de Sa University | Braga I.G.,Estacio de Sa University | Albuquerque A.C.,Estacio de Sa University | And 15 more authors.
Stem Cell | Year: 2010

Objective: The Saccharomyces cerevisiae, a species of yeast, is used as a model of study for several types of purposes, exceeding then, as a model of biological application to the glucose human metabolism. The microcurrent can produce the lesser amount of measurable electric chains with similar and compatible electric signals to the electromagnetic field of the human body when these are recovering from tissue injury or has disruption of its normal electric activity. Also, it would stimulate a metabolic alteration to the point where it produces significant amounts and until the modulating of energy in the form of Adenosine Triphosfate - (ATP). The goal of this study was to evaluate the effect of the microcurrent through the parameters of the absorbance and pH in the metabolism of the glucose to explore the human similarities and the capacity of inquiry that the Saccharomyces cerevisiae supplies. Methods: One of the methods of glucose determination in used liquid samples more in the world and widely used in assays biochemists of dosage of reducing sugars and for studies of kinetic enzymatic is of the acid dinitrosalicylic (DNS), discovered in the end of the decade of 50 (Miller, L., 1959). The pH measurements have been performed in the chemistry from the very beginning; in this case it was used for H+ detection and the pH measured correlated to the total glucose concentration present in the sample. First, we apply the microcurrent of three distinct intensities in liquid samples of saccharomyces; later the glucose for the metabolization was added. Second, we submit the samples for the analysis of the absorbance and pH for possible verification of the metabolization of the glucose and evaluation of the results. Results: In this study, it could be observed that the treatment, depending on the intensity of the applied microcurrent, caused an increase of the absorbance and pH when observed for the intensities of 100μA, 500μA and 900μA, showing that the cells had absorbed little glucose. Conclusion: From the analysis of the acquired results, it can be suggested that the evaluated microcurrent is capable of modifying the glucose and calcium captation in the leavenings with the increase of the absorbance and pH. Source

Fidelis Q.C.,Federal Rural University of Rio de Janeiro | Castro R.N.,Federal Rural University of Rio de Janeiro | Guilhon G.M.S.P.,Federal University of Para | Rodrigues S.T.,Embrapa Amazonia Oriental | And 3 more authors.
Molecules | Year: 2012

The chemical study of the extracts from leaves and stems of Ouratea ferruginea allowed the identification of a new isoflavone, 5-hydroxy-7, 3′4′5′-tetramethoxyisoflavone, and twenty two known compounds, including friedelin, 3ß-friedelinol, lupeone, a mixture of sitosterol, stigmasterol and campesterol, sitosteryl- and stigmasteryl-3-O-b- Dglucopyranosides, 5, 4′-dihydroxy-7, 5′, 3′- trimethoxyisoflavone, 5, 4′-dihydroxy-7, 3′-dimethoxyisoflavone (7, 3′-di-O-methylorobol), 5, 7, 4′-trihydroxy-3′, 5′-dimethoxyisoflavone (piscigenin), 2R, 3R-epicatechin, syringic acid, 2, 6-dimethoxybenzoquinone, 2, 6-dimethoxyhydroquinone, syringic and ferulic aldehyde, a mixture of vanillic acid, 1-hydroxy-2-methoxy-4-(1E-3-hydroxy-1- propenyl)-benzene and 3, 5-dimethoxy-4-hydroxydihydrocinamaldehyde, besides amenthoflavone and 7-O-methylamenthoflavone (sequoiaflavone) which are considered as chemotaxonomic markers of Ouratea. The structures were identified by IR, 1H- and 13CC-NMR and GC-MS, HPLC-MS, besides comparison with literature data. The inhibitory effects of 5, 4′-dihydroxy-7, 5′, 3′- trimethoxyisoflavone, 7, 3′-di-O-methylorobol, piscigenin and 7-O-methylamenthoflavone on cytochrome P450-dependent 7-ethoxycoumarin O-deethylase (ECOD) and glutathione S-transferase (GST) were evaluated in vitro. The 5, 4′-dihydroxy-7, 5′, 3′-trimethoxyisoflavone was the best inhibitor, inhibiting almost 75% of GST activity. Sequoiaflavone was the most potent inhibitor, inhibiting ECOD assay in 75%. These activities allow us to consider both these flavonoids as potential anticancer and chemopreventive agents. © 2012 by the authors. Source

Costa M.,Federal University of Rio de Janeiro | Costa M.,Centro Universitario da Zona Oeste | Zavaleta J.,Federal University of Rio de Janeiro | Da Cruz S.M.S.,Federal University of Rio de Janeiro | And 5 more authors.
Proceedings of CBMS 2013 - 26th IEEE International Symposium on Computer-Based Medical Systems | Year: 2013

This paper aims to present a computational tool based on neural networks to detect people with possible learning disabilities (dyslexia). Participants were aged from nine to 18 years old with or without the diagnosis of dyslexia. Neural networks technique showed consistency in dealing with the problems of pattern recognition in the screening of dyslexia. © 2013 IEEE. Source

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