1,721,182 research outputs found
György Inzelt, Andrzej Lewenstam and Fritz Scholz (Eds.): Handbook of reference electrodes
No full textComments about a new book are mad
Cyclic Staircase Voltammetry as a dc and ac Electroanalytical Technique
No full textFourier analysis is used to deconvolve,from a square wave voltammogram, the continuous current response to the alternating one
Analog and digital worlds: Part 1. Signal sampling and Fourier Transform
No full textProper data sampling of a continuously varying quantity that describes the proceeding of a natural process leads to a simpler equivalent representation. This representation consists of a sequence of discrete data, which is more suitable to be mathematically handled and allows one not to lose essential information provided by the original signal. The discrete values of the sequence obtained by sampling differ from one another by finite quantities. In the ideal case, the original representation should be perfectly reconstructed by a backward procedure. The rules that should be respected in order to satisfy this basic condition are very simple, but require the decomposition of the signal into a suitable set of elementary components. This may be performed by applying to the sequence the algorithm called Discrete Fourier Transform (DFT). The direct result of the transformation consists of the spectrum of the signal, which can be analysed in many ways. The mathematics to make the FT algorithm work, eventually in an as fast as possible way (FFT – Fast Fourier Transform) is perhaps of less interest to the chemists and will not be treated here. Rather, the aim is to address the reader about what FT allows to obtain
Transform Methods in the Synthesis and Elaboration of Signals
No full textDifferent transform methods, from Fourier Transform to Wavelet Transform, are discussed and exemplifie
La Trasformata Discreta di Fourier. Applicazioni in Chimica Analitica
No full textNella serie Rassegne di Scienza e Tecnologia è presentata la definizione di FT e DFT, le operazioni di filtraggio - convoluzione e deconvoluzione - e alcune applicazioni strumentali, nonché di elaborazione dat
Square Wave Voltammetry as an Electroanalytical Technique for Measuring Pure Faradic Currents
No full textA theory is elaborated in order to extract from a square wave voltammteric curve the relevant cyclic voltammetric responses, purged by the capacitive curve. The analysis of the response results much easier
Minicomputer-based instrumentation for electroanalytical techniques
No full textThe system comprises a PDP 11/23 PLUS (16-bit) computer and a home-made electrochemical interface which includes digital/analog and analog/digital conversion circuits, a potentiostat, and programmable timers allowing fast data transfer. The software developed includes operating system routines and user-level programs for cyclic voltammetry and chronoamperometry. The whole system provides the user with a computer-aided execution of experiments, including potential waveform synthesis and collection and evaluation of responses
Electrochemical Reduction of Triphenyltin Chloride in Aprotic Medium
No full textThe electrode mechanism for the reduction of theSnPh3Cl organometallic species in aprotic solvent is define
Links between electrochemical thermodynamics and kinetics
No full textRedox systems are considered when proceeding (a) in an electrochemical cell (heterogeneous reactions), and (b) in a single compartment (homogeneous reactions), also including the case of a solution in contact with solid phases. Special emphasis is given to the electrochemical systems. Starting from equilibrium states in the individual half-cells, the cell as a whole is (1) made to work spontaneously (batteries, fuel cells) and (2) forced to induce non-spontaneous transformations (electrolysis). Kinetics needs to be considered in both cases: phenomenological aspects and rigorous mathematic tools are intended to concur to draw the picture. Supplementary material is given in order to help visualise what the equations given express
PEDOT modified microelectrodes. Preparation, characterisation and analytical performances
No full textPoly(3,4-ethylenedioxythiophene) (PEDOT) modified microelectrodes were prepared by electropolymerisation of therelevant monomer from CH3CN and H2O solutions. The electrochemical behaviour of the obtained coatings wasinvestigated by cyclic voltammetry in both organic and aqueous media. The anodic responses obtained for a typicalbenchmark analyte such as ascorbic acid have been chosen in order to test the different coatings; calibration curves havebeen built up in order to evaluate the repeatability of the response and reproducibility of the realised sensing system.Moreover, the ability of the modified microelectrodes to work in low conductivity media has been studied, and exploratorytests in dense food matrix have been performe
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