Signal Detection
Mostrando 25-36 de 862 artigos, teses e dissertações.
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25. Development of a Novel and Simple Electroanalytical Procedure for the Determination of Copper in Biofuel Employing a Sensor Based on Vulcan Functionalized with Carbazone
A novel and simple electroanalytical method for the determination of Cu2+ in biodiesel samples by stripping voltammetric analysis was developed. The method employs a carbon paste electrode (CPE) modified with Vulcan carbon, previouly functionalized with carbazone (CBZ). The CPE/Vulcan-CBZ sensor promoted a significant increase in the analytical signal obtain
J. Braz. Chem. Soc.. Publicado em: 2018-04
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26. A Novel Sensitive Bulk Optode Based on 5-Br Salophen as an Ionophore for Determination of Zinc Ion in Real Samples
An optical sensing film was fabricated for sensitive determination of zinc ion in aqueous solutions. The optical sensor was prepared by synthesized ionophore, 5-Br salophen, dioctyl sebacate (DOS) as a plasticizer, sodium tetraphenyl borate (NaTPB) as a lipophilic anionic additive in a poly(vinyl chloride) membrane. The optode response is based on the cation
J. Braz. Chem. Soc.. Publicado em: 2018-03
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27. Determination of Chlorine in Crude Oil Emulsified via the MgCl Molecule by HR-CS MAS
A method for chlorine determination in crude oil samples, through the formation of MgCl molecule, by high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS GF MAS) was developed and is described in this paper. The use of this molecule for chlorine determination in crude oil has not been reported up to now. Measures were ca
J. Braz. Chem. Soc.. Publicado em: 2018-03
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28. Modeling and FPGA-based implementation of an efficient and simple envelope detector using a Hilbert Transform FIR filter for ultrasound imaging applications
Abstract Introduction Although the envelope detection is a widely used method in medical ultrasound (US) imaging to demodulate the amplitude of the received echo signal before any back-end processing, novel hardware-based approaches have been proposed for reducing its computational cost and complexity. In this paper, we present the modeling and FPGA impleme
Res. Biomed. Eng.. Publicado em: 15/01/2018
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29. Application of Response Surface Modeling and Chemometrics Methods for the Determination of Ofloxacin in Human Urine Using Dispersive Liquid-Liquid Microextraction Combined with Spectrofluorimetry
Dispersive liquid-liquid microextraction (DLLME) and spectrofluorimetry, coupled with chemometrics methods, are proposed in this work for the pre-concentration and determination of ofloxacin concentration in spiked human urine. Chloroform and acetonitrile were selected as the extraction and dispersive solvents by the one-variable-at-a-time process. The Box-B
J. Braz. Chem. Soc.. Publicado em: 2017-12
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30. An automatic gain control circuit to improve ECG acquisition
Abstract Introduction Long-term electrocardiogram (ECG) recordings are widely employed to assist the diagnosis of cardiac and sleep disorders. However, variability of ECG amplitude during the recordings hampers the detection of QRS complexes by algorithms. This work presents a simple electronic circuit to automatically normalize the ECG amplitude, improving
Res. Biomed. Eng.. Publicado em: 30/11/2017
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31. Femtoliter Scale Detection of an Antithyroid Drug Using Gold Nanoparticles in a Microfluidic Chip
Sensitive detection of methimazole (MMI) at the femtoliter (fL) scale has been achieved based on photo thermal lensing of gold nanoparticles (GNPs). GNPs were used because their surface plasmon resonance (SPR) have absorption in visible range. A combined glass microfluidic chip-photo thermal lens microscopy (MFC-PTLM) system with appropriate laser source was
J. Braz. Chem. Soc.. Publicado em: 2017-10
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32. Development of a skateboarding trick classifier using accelerometry and machine learning
Abstract Introduction Skateboarding is one of the most popular cultures in Brazil, with more than 8.5 million skateboarders. Nowadays, the discipline of street skating has gained recognition among other more classical sports and awaits its debut at the Tokyo 2020 Summer Olympic Games. This study aimed to explore the state-of-the-art for inertial measurement
Res. Biomed. Eng.. Publicado em: 2017-10
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33. Matrix Damage Detection in Laminated Composite Structures by Discrete and Continuous Wavelet Transforms Using Vibration Modes
ABSTRACT: In this paper it was sought to enhance the potential damage detection, location and quantification of the Discrete and Continuous Wavelet Transforms in thin damaged laminated composite plates by a signal derived from vibration modes. To evaluate the ability of both transforms in the damage prognostic it was also proposed the use of Damage Indexes.
J. Aerosp. Technol. Manag.. Publicado em: 21/09/2017
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34. Sensitive Estrogens Determination in Wastewater Samples by HPLC and Fluorescence Detection
A sensitive high-performance liquid chromatography-fluorescence detection method (HPLC-FLD) was developed and validated for 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) determination in wastewater samples. Sample preparation was performed by solid-phase extraction (SPE) on Hypersep C18 cartridges. Conditioning and elution solvents and sample volume we
J. Braz. Chem. Soc.. Publicado em: 2017-08
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35. VALIDAÇÃO DE MÉTODO POR MEFS-HS/CG-EM PARA DETERMINAÇÃO DE CARBARIL EM PLASMA SANGUÍNEO
The aim this research is to develop a HS-SPME/GC-MS method to analyze the carbaryl in blood plasma samples of the rural workers, who live round the perimeter of Chapada do Apodi-CE. This was achieved by chromatographic signal of the 1-naftol, degradation product of carbaryl with the intention of evaluating the degree of exposure of the workers to pesticides,
Quím. Nova. Publicado em: 2017-06
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36. Low Potential and Non-Enzymatic Hydrogen Peroxide Sensor Based on Copper Oxide Nanoparticle on Activated Pencil Graphite Electrode
An electrochemical sensor for H2O2 determination was prepared by electrodepositing copper oxide nanoparticles on the activated pencil graphite electrodes. At first, a study has been made of the optimum conditions for chemical activation of the pencil graphite electrodes (APGE) and then the activated pencil graphite electrode was modified with copper oxide na
J. Braz. Chem. Soc.. Publicado em: 2017-05