902 resultados para CHRONOPOTENTIOMETRY WITH LINEAR CURRENT SCANNING


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Linear Matrix Inequalities (LMIs) is a powerful too] that has been used in many areas ranging from control engineering to system identification and structural design. There are many factors that make LMI appealing. One is the fact that a lot of design specifications and constrains can be formulated as LMIs [1]. Once formulated in terms of LMIs a problem can be solved efficiently by convex optimization algorithms. The basic idea of the LMI method is to formulate a given problem as an optimization problem with linear objective function and linear matrix inequalities constrains. An intelligent structure involves distributed sensors and actuators and a control law to apply localized actions, in order to minimize or reduce the response at selected conditions. The objective of this work is to implement techniques of control based on LMIs applied to smart structures.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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We show that the emission of a Minkowski particle by a general class of scalar sources as described by inertial observers corresponds to either the emission or the absorption of a Rindler particle as described by uniformly accelerated observers. Our results are discussed in connection with the current controversy whether uniformly accelerated detectors radiate.

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Microhabitat and plant structure of seven Batrachospermum populations (four of Batrachospermum delicatulum (= Sirodotia delicatula), one of Batrachospermum macrosporum and two of the 'Chantransia' stage), including the influence of physical variables (current velocity, depth, irradiance and substratum), were investigated in four streams of São Paulo State, southeastern Brazil. The populations of B. delicatulum and the 'Chantransia' stage occurred under very diverse microhabitat conditions, which probably contributes to their wide spatial and seasonal distribution in Brazilian streams. Results suggest branch reconfiguration as a probable mechanism of adaptation to current velocity based on the occurrence of: (i) B. macrosporum (a large mucilaginous form with presumably little ability for branch reconfiguration) under lower current velocity than B. delicatulum; (ii) only dense plants in populations with high current velocities (> 60 cm s-1), whereas 53-77% of dense plants were seen in populations exposed to lower currents (< 40 cm s-1); (iii) positive correlations of plant length with internode length in populations under low current velocities and negative correlation in a population with high velocity (132 cm s-1); and (iv) negative correlations of current velocity with plant diameter and internode length in a population under high flow. This study, involving mainly dioecious populations, revealed that B. delicatulum displayed higher fertilization rates than B. macrosporum. A complementary explanation for a dioecious species to increase fertilization success was proposed consisting of outcrossing among intermingled male and female adjacent plants within an algal spot.

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This paper describes a analog implementation of radial basis neural networks (RBNN) in BiCMOS technology. The RBNN uses a gaussian function obtained through the characteristic of the bipolar differential pair. The gaussian parameters (gain, center and width) is changed with programmable current source. Results obtained with PSPICE software is showed.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Pharmacovigilance is accomplished by voluntary notification of suspected adverse reactions, medication errors, and deviations from quality, by users and health professionals, through the filling in of forms that are sent to a data bank. To broaden the sources of notifications, the National Health Surveillance Agency (ANVISA), in partnership with the Regional Pharmacy Council (CRF) and Center for Health Surveillance (CVS) of each state, introduced the scheme of Notifying Pharmacies. The present study was aimed at determining the factors influencing the decision of drugstores and private pharmacies in Tatuí/SP in 2007, to join this project A descriptive, observational survey of knowledge, attitude and practice (KAP) was applied to volunteer pharmacists in the town. The results showed that the professionals are awave of pharmacovigilance, (95.24%) and have attitude (95.24%). However, practice is limited (6.0%). Based on this information we concluded that the low support of the project was due to lack of time, interest and no information about the benefits to society of such activity and a lack of support from the pharmacists' organizations. This situation is expected to change with the current introduction of a professional profile, the fusion of professional bodies and the promotion of social awareness on pharmacovigilance.

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This paper presents a methodology and a mathematical model to solve the expansion planning problem that takes into account the effect of contingencies in the planning stage, and considers the demand as a stochastic variable within a specified range. In this way, it is possible to find a solution that minimizes the investment costs guarantying reliability and minimizing future load shedding. The mathematical model of the expansion planning can be represented by a mixed integer nonlinear programming problem. To solve this problem a specialized Genetic Algorithm combined with Linear Programming was implemented.

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This paper deals with results of a research and development (R&D) project in cooperation with Electric Power Distribution Company in São Paulo (Brazil) regarding the development and experimental analysis of a new concept of power drive system suitable for application in traction systems of electrical vehicles pulled by electrical motors, which can be powered by urban DC or AC distribution networks. The proposed front-end structure is composed by five boost power cells in interleaving connection, operating in discontinuous conduction mode as AC-DC converter, or as DC-DC converter, in order to provide the proper DC output voltage range required by DC or AC adjustable speed drivers. Therefore, when supplied by single-phase AC distribution networks, and operating as AC-DC converter, it is capable to provide high power factor, reduced harmonic distortion in the input current, complying with the restrictions imposed by the IEC 61000-3-4 standards resulting in significant improvements for the trolleybuses systems efficiency and for the urban distribution network costs. Considering the compliance with input current restrictions imposed by IEC 61000-3-4 standards, two digital control strategies were evaluated. The digital controller has been implemented using a low cost FPGA (XC3S200) and developed totally using a hardware description language VHDL and fixed point arithmetic. Experimental results from a 15 kW low power scale prototype operating in DC and AC conditions are presented, in order to verify the feasibility and performance of the proposed system. © 2009 IEEE.

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In this study, the attitudes of students and teachers at the Faculty of Pharmaceutical Sciences of Araraquara (UNESP University) towards Biostatistics were assessed. The Survey of Attitudes Toward Statistics (SATS) scale was used as the measuring instrument. The reproducibility of the scale was estimated by Cohen's Kappa (κ) coefficient with linear weighting and its internal consistency by Cronbach's alpha coefficient (α). The individuals were first placed in two groups, according to their positive or negative attitude toward Statistics; then, the association of their attitude with the variables of interest was tested by the chi-squared (χ 2) test at a significance level of 5%. The sample consisted of 272 undergraduate students, 83 graduate students and 24 teachers, predominantly female (78.2%). Among the students, 67.5% participated in the scientific research initial training program. Reproducibility and internal consistency of the scale were adequate (κ=0.7093; α=0.9334). Most of the subjects (74.4%) had a positive attitude toward Statistics. Significant association was found between attitude and functional activity (p=0.0204), the course taken (p=0.0316) and effort (p=0.0002). Thus, it was concluded that the great majority of the participants had a positive attitude towards Biostatistics and that undergraduate students and those who reported good performance in Biostatistics showed a significantly higher proportion of positive attitude than the other students.

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Includes bibliography

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Includes bibliography

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This work describes a method to determine Cu at wide range concentrations in a single run without need of further dilutions employing high-resolution continuum source flame atomic absorption spectrometry. Different atomic lines for Cu at 324. 754 nm, 327. 396 nm, 222. 570 nm, 249. 215 nm and 224. 426 nm were evaluated and main figures of merit established. Absorbance measurements at 324. 754 nm, 249. 215 nm and 224. 426 nm allows the determination of Cu in the 0. 07-5. 0 mg L -1, 5. 0-100 mg L -1 and 100-800 mg L -1 concentration intervals respectively with linear correlation coefficients better than 0. 998. Limits of detection were 21 μg L -1, 310 μg L -1 and 1400 μg L -1 for 324. 754 nm, 249. 215 nm and 224. 426 nm, respectively and relative standard deviations (n = 12) were ≤ 2. 7%. The proposed method was applied to water samples spiked with Cu and the results were in agreement at a 95% of confidence level (paired t-test) with those obtained by line-source flame atomic absorption spectrometry.

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Includes bibliography