Determination of Tortuosity Using Impedance Spectra Analysis of Symmetric Cell

2017 ◽  
Vol 164 (11) ◽  
pp. E3329-E3334 ◽  
Author(s):  
Simon Malifarge ◽  
Bruno Delobel ◽  
Charles Delacourt
Keyword(s):  
Impedance Spectra ◽  
Spectra Analysis

scholarly journals Differential impedance spectra analysis reveals optimal actuation frequency in bulk mode acoustophoresis

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Valentina Vitali ◽  
Giulia Core ◽  
Fabio Garofalo ◽  
Thomas Laurell ◽  
Andreas Lenshof
Keyword(s):  
Precise Determination ◽  
Impedance Spectra ◽  
Actuation Frequency ◽  
Spectra Analysis ◽  
Resonance Modes ◽  
Bulk Mode ◽  
Working Frequency ◽  
First Time ◽  
Channel Resonance

AbstractThis work reports a method to select the optimal working frequency in transversal bulk resonator acoustophoretic devices by electrical impedance measurements. The impedance spectra of acoustophoretic devices are rich in spurious resonance peaks originating from different resonance modes in the system not directly related to the channel resonance, why direct measurement of the piezoelectric transducer impedance spectra is not a viable strategy. This work presents, for the first time, that the resonance modes of microchip integrated acoustophoresis channels can be identified by sequentially measuring the impedance spectra of the acoustophoretic device when the channel is filled with two different fluids and subsequently calculate the Normalized Differential Spectrum (NDS). Seven transversal bulk resonator acoustophoretic devices of different materials and designs were tested with successful results. The developed method enables a rapid, reproducible and precise determination of the optimal working frequency.

Synthesis, Electrical Properties and Chemical Stability of BaCe0.7In0.3-xGdxO3-δ

2016 ◽  
Vol 848 ◽  
pp. 401-410 ◽  
Author(s):  
Jia Huan Xu ◽  
Wei Han ◽  
Hui Ding ◽  
Wei Jin Chen ◽  
Jun Xiang
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Chemical Stability ◽  
Perovskite Structure ◽  
Doping Concentration ◽  
Interplanar Spacing ◽  
Sol Gel ◽  
Impedance Spectra ◽  
Spectra Analysis ◽  
Diffraction Angle

In3+, Gd3+ were selected as substitution elements for Ce4+ in order to increase electrical conductivity and chemical stability of BaCeO3. A modified sol-gel method was used to fabricate BaCe0.7In0.3-xGdxO3-δ (x = 0, 0.1, 0.2, 0.3) nanopowders. XRD results indicated that the diffraction angle moved to lower with increase of the Gd3 + doping concentration, so that the interplanar spacing gradually increased. The impedance spectra analysis showed that conductivity first increased (x = 0~0.2) and then decreased with the Gd3 + doping increase. The total conductivities at 800oC were 3.8 × 10-3 S·cm-1 (x = 0), 8.0 × 10-3 S· cm-1 (x = 0.1), 2.5 × 10-2 S· cm-1 (x = 0.2), 1.36 × 10-2 S ·cm-1 (x = 0.3). Chemical stability test in CO2 show that all samples except for x=0.3 sample calcination at 800oC for 2h under 100% CO2 and x=0, 0.1 samples heating in boiling water for 12h kept main perovskite structure. Therefore, x=0.1 sample show better electrical conductivity and chemical stability.

Electro-Diffusion in Multicomponent Ion-Selective Membranes; Numerical Solution of the Coupled Nernst–Planck–Poisson Equations

2008 ◽  
Vol 273-276 ◽  
pp. 113-118 ◽  
Author(s):  
Bartosz Grysakowski ◽  
Bogusław Bożek ◽  
Marek Danielewski
Keyword(s):  
Low Frequency ◽  
Membrane Electrodes ◽  
Impedance Spectra ◽  
Small Current ◽  
Poisson Equations ◽  
Continuity Equations ◽  
Transient Solutions ◽  
Linear Effects ◽  
Characteristic Features

Numerical simulations of evolution of the potentials and impedance spectra of ionselective membranes (ISEs) with ionic sites are presented. The Nernst–Planck–Poisson and continuity equations (NPP) are solved numerically by means of the finite difference method, the Rosenbrock solver and with the use of Matlab platform. Transient solutions for ion-selective electrodes under open- and closed-circuit conditions are computed. The potential-time response to small-current perturbation is used for determination of complex impedances. We present simulations of ISEs as a function of varying diffusivities and ionic concentrations in the “bathing” solutions at interfaces. It is shown that the non-Nernstian behavior of passive membrane electrodes is a result of kinetic constraints at the interfaces, which is manifested in the appearance of an additional arc between the high-frequency bulk and the low-frequency (Warburg) arcs. The presented approach directly relates the diffusivities in the membrane and the interface properties (heterogeneous rate constants determining the transport across interfaces) to the characteristic features of impedance spectra (dimensions and characteristic radial frequencies). NPP problem solved on the Matlab platform allows simulating of the non-linear effects in electro-diffusion.

Impedance spectra analysis of thermoresponsive poly(acryloyl-L-proline methyl ester) gel membrane in LiCl solution

2005 ◽  
Vol 43 (20) ◽  
pp. 2843-2851
Author(s):  
Jinhua Chen ◽  
Masaharu Asano ◽  
Norio Tsubokawa ◽  
Yasunari Maekawa ◽  
Tetsuya Yamaki ◽  
...  
Keyword(s):  
Methyl Ester ◽  
Impedance Spectra ◽  
Spectra Analysis

scholarly journals Electrochemical Characteristics of Particulate Matter

2011 ◽  
Vol 7 (-1) ◽  
pp. 19-26 ◽  
Author(s):  
Margarita Baitimirova ◽  
Agnese Osite ◽  
Juris Katkevich ◽  
Arturs Viksna
Keyword(s):  
Particulate Matter ◽  
Double Layer ◽  
Mass Concentration ◽  
Electrochemical Impedance ◽  
Cyclic Voltammograms ◽  
Electrochemical Characteristics ◽  
Impedance Spectra ◽  
Double Layer Capacitance ◽  
Spectra Analysis ◽  
Aerosol Mass Concentration

Electrochemical Characteristics of Particulate Matter The current work is dedicated to electrochemical impedance spectra analysis of the fine and coarse airborne particulate matter sampled on the glass fibre filters in Riga city air. The cyclic voltammograms, impedance spectra and double layer capacitance spectra of particulate matter were obtained after the pre-treatment of samples. The equivalent circuit method and the statistical method were used for impedance spectra analysis. Analyzing the impedance spectra, it was concluded that the impedance of both - fine and coarse particles heated in N2 flow does not change by aerosol mass concentration variations. On the other hand, the impedance of particulate matter heated in O2 flow increases, by increasing PM10 mass concentration. Describing the spectra of double layer capacitance, it was observed that the double layer capacitance of aerosols heated in N2 flow did not change, by mass concentration and size variations. However, by increasing mass concentration of coarse aerosols heated in O2 flow, the double layer capacitance reduced.

Determination of boron in water samples by dispersive liquid–liquid microextraction based on the solidification of a floating organic drop coupled with a fluorimetric method

The Analyst ◽  
2016 ◽  
Vol 141 (7) ◽  
pp. 2313-2318 ◽  
Author(s):  
Guilong Peng ◽  
Qiang He ◽  
Haifang Li ◽  
Daniel Mmereki ◽  
Ying Lu ◽  
...  
Keyword(s):  
Water Samples ◽  
Fluorescence Spectra ◽  
Spectra Analysis ◽  
Fluorimetric Method ◽  
Dispersive Liquid Liquid Microextraction ◽  
Liquid Microextraction

Dispersive liquid–liquid microextraction based on the solidification of a floating organic drop (DLLME-SFO) prior to fluorescence spectra analysis.

Sign in / Sign up

Export Citation Format

Share Document