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A simple and efficient method is described for the determination of fenpropathrin in oranges, pears, apples and strawberries. The procedure: is based on the extraction of each homogenized fruit sample with hexane:acetone (1:1, v/v) mixture, followed, by a cleanup technique on a column packed with florisil, using a hexane:ethyl ether (7:3, v/v) mixture, and gas chromatographic, analysis with electron capture detection (ECD). The fortification levels (0.5; 1.0; 2.0 mg kg(-1)) were selected according to the maximum residue limits (MRLs) established for fenpropathrin by Brazilian legislation. Mean recoveries from five replicates of fortified fruit samples ranged from 83 % to 98 %, with:coefficients of variation from 1.4 to 13.5 and detection limits varying from 0.1 to 0.2 mg kg(-1).

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This work presents the design of a fuzzy controller with simplified architecture. This architecture tries to minimize the time processing used in? the several stages of hazy modeling of systems and processes. The basic procedures of fuzzification and defuzzification are simplified to the maximum while the inference procedures are computed in private way. Therefore, the simplified architecture allows a fast and easy configuration of the fuzzy controller.All rules that define the control actions are determined by inference procedures and the defuzzification is made automatically using a simplified algorithm. The fuzzy controller operation is standardized and the control actions are previously calculated For general-purpose application? ann results, the industrial systems of fluid pow cona ol will be considered.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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A rapid and sensitive method is described for the determination of clofentezine residues in apple, papaya, mango and orange. The procedure is based on the extraction of the sample with a hexane:ethyl acetate mixture (1:1, v/v) and liquid chromatographic analysis using UV detection. Mean recoveries from 4 replicates of fortified fruit samples ranged from 81% to 96%, with coefficients of variation from 8.9% to 12.5%. The detection and quantification limits of the method were of 0.05 and 0.1 mg kg-1, respectively.

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A simple, rapid, and sensitive spectrophotometric method for routine analysis of saccharin in commercial noncaloric sweeteners is proposed. This method is based on the reaction of saccharin with tetrachloro-p-benzoquinone (p-chloranil) accelerated by hydrogen peroxide and conducted in an ethanol:acetone (4:1) medium, producing a violet-red compound (γ max = 550 nm). Beer's law is obeyed in a concentration range of 2.05 × 10 -4 to 3.00 × 10 -3 M with an excellent correlation coefficient (r = 0.9998). The detection limit was 1.55 × 10 -5 M, and the effect of interferences on the spectrophotometric measurements was evaluated. The proposed procedure was applied successfully to the determination of saccharin in noncaloric sweeteners. Recoveries were within 99.2-104.3% with standard deviations ranging from to 0.5-1.6%. Results of the proposed method compare very favorably with those given by the high-performance liquid chromatography method recommended by the Food and Drug Administration.

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This paper describes a simple, portable and environmentally friendly method for the rapid determination of dipyrone in pharmaceuticals by using diffuse reflectance spectroscopy. The proposed method is based on the reflectance measurements of the orange compound produced from the spot test reaction between dipyrone and p-dimethylaminocinnamaldehyde (p-DAC), in acid medium, using a filter paper as solid support. Experimental design methodologies were used to optimize the measurement conditions. All reflectance measurements were carried out at 510 nm and the linear range was from 1.42 × 10-4-2.85 × 10-3 mol L-1, with a correlation coefficient of 0.999. The limit of detection (LOD) and the limit of quantification (LOQ) were 1.20 × 10-5 mol L-1 and 4.00 × 10-5 mol L-1, respectively. The intraday precision and interday precision were studied for 10 replicate analyses of 7.90 × 10-4 mol L-1 dipyrone solution. The coefficients of variation were 1.1 and 0.9%, respectively. The proposed method was applied successfully to the determination of dipyrone in commercial brands of pharmaceuticals. No interferences were observed from the common excipients in formulations. The results obtained by the proposed method were favorably compared with those given by the Brazilian Pharmacopoeia procedure at 95% confidence level. ©2007 Sociedade Brasileira de Química.

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The aim of this paper is to present a simple method for determining the high frequency parameters of a three-phase induction motor to be used in studies involving variable speed drives with PWM three-phase inverters, in which it is necessary to check the effects caused to the motor by the electromagnetic interference, (EMI) in the differential mode, as well as in the common mode. The motor parameters determination is generally performed in adequate laboratories using accurate instruments, such as very expensive RLC bridges. The method proposed here consists in the identification of the motor equivalent electrical circuit parameters in rated frequency and in high frequency through characteristic tests in the laboratory, together with the use of characteristic equations and curves, shown in the references to be mentioned for determining the motor high frequency parasite capacitances and also through system simulations using dedicated software, like Pspice, determining the characteristic waveforms involved in the differential and common mode phenomena, comparing and validating the procedure through published papers [01].

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Purpose. The purpose of this study was to evaluate the discrepancies between abstracts presented at the IADR meeting (2004-2005) and their full-text publication. Material and Methods. Abstracts from the Prosthodontic Section of IADR meeting were obtained. The following information was collected: abstract title, number of authors, study design, statistical analysis, outcome, and funding source. PubMed was used to identify the full-text publication of the abstracts. The discrepancies between the abstract and the full-text publication were examined, categorized as major and minor discrepancies, and quantified. The data were collected and analyzed using descriptive analysis. Frequency and percentage of major and minor discrepancies were calculated. Results. A total of 109 (95.6%) articles showed changes from their abstracts. Seventy-four (65.0%) and 105 (92.0%) publications had at least one major and one minor discrepancies, respectively. Minor discrepancies were more prevalent (92.0%) than major discrepancies (65.0%). The most common minor discrepancy was observed in the title (80.7%), and most common major discrepancies were seen in results (48.2%). Conclusion. Minor discrepancies were more prevalent than major discrepancies. The data presented in this study may be useful to establish a more comprehensive structured abstract requirement for future meetings. © 2012 Soni Prasad et al.

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Modal analysis is widely approached in the classic theory of transmission line modeling. This technique is applied to model the three-phase representation of conventional electric systems taking into account their self and mutual electrical parameters. However the methodology has some particularities and inaccuracies for specific applications which are not clearly described in the basic references of this topic. This paper provides a thorough review of modal analysis theory applied to line models followed by an original and simple procedure to overcome the possible errors embedded in the modal decoupling through the three-phase system modeling. © 2012 IEEE.

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A transmission line digital model is developed direct in the phase and time domains. The successive modal transformations considered in the three-phase representation are simplified and then the proposed model can be easily applied to several operation condition based only on the previous knowing of the line parameters, without a thorough theoretical knowledge of modal analysis. The proposed model is also developed based on lumped elements, providing a complete current and voltage profile at any point of the transmission system. This model makes possible the modeling of non-linear power devices and electromagnetic phenomena along the transmission line using simple electric circuit components, representing a great advantage when compared to several models based on distributed parameters and inverse transforms. In addition, an efficient integration method is proposed to solve the system of differential equations resulted from the line modeling by lumped elements, thereby making possible simulations of transient and steady state using a wide and constant integration step. © 2012 IEEE.