On the electrochemical impedance of InP and GaAs electrodes in indifferent electrolyte. Part 1. Analytical description of the frequency dispersion

1999 ◽  
Vol 1 (15) ◽  
pp. 3607-3615 ◽  
Author(s):  
Z. Hens ◽  
W. P. Gomes
Keyword(s):  
Electrochemical Impedance ◽  
Frequency Dispersion ◽  
Analytical Description ◽  
Indifferent Electrolyte

High-Frequency Features in the Distribution of Relaxation Times Related to Frequency Dispersion Effects in SOFCs

2021 ◽  
Author(s):  
Katharina Fitzek ◽  
Ute de Haart ◽  
Qingping Fang ◽  
Werner Lehnert
Keyword(s):  
Fuel Cells ◽  
High Frequency ◽  
Electrochemical Impedance ◽  
Relaxation Times ◽  
Frequency Dispersion ◽  
High Frequency Range ◽  
Frequency Range ◽  
Root Cause ◽  
Complex Planes ◽  
User Friendly

Abstract Electrochemical impedance spectroscopy (EIS) is commonly used for the characterization of electrochemical systems, such as solid oxide fuel cells (SOFCs). In recent years, the distribution of relaxation times (DRT) analysis has attracted increasing interest as a tool for investigating electrochemical loss mechanisms in fuel cells due to its ability to resolve electrochemical features that overlap in complex planes. Among the methods used for the deconvolution of the distribution function of relaxation times, DRTtools is commonly used due to its user-friendly graphical user interface. In this study, we investigate the root cause of the expression of additional DRT features in the high-frequency range and link them to characteristic properties of the processes that contribute to the polarization loss of SOFCs. Identification of the root cause leading to the expression of the features is performed by conducting a simulation study with synthetic EIS spectra that are then analyzed using DRTtools. It has been shown that the constant phase element behavior of high-frequency processes in SOFCs is the root cause of the expression of additional peaks in the high-frequency range of the DRT.

EIS: Measurement Model Program

2020 ◽  
Author(s):  
William Watson ◽  
Mark Edward Orazem
Keyword(s):  
Operating System ◽  
Electrochemical Impedance ◽  
Frequency Dispersion ◽  
Measurement Model ◽  
Model Program ◽  
University Of Florida ◽  
Ohmic Resistance ◽  
Stochastic Error ◽  
Sample Data ◽  
Reference Manual

The measurement model is used to analyze electrochemical impedance spectroscopy (EIS) data. The measurement model installation file works with the MS Windows operating system. With this program, you will be able to identify the stochastic error structure of your measurements, used to weight further regressions. You will be able to determine what part of your measurement is inconsistent with the Kramers-Kronig relations. You will be able to estimate capacitance and ohmic resistance, from which you can identify the characteristic frequency above which the geometry of the electrode may cause frequency dispersion. You will also be able to fit custom models to your data. The reference manual, reached from the Help Tab, also provides links to sample data, custom models, and Python code.Copyright ©2020, University of Florida Research Foundation, Inc., All Rights Reserved.

Quantitative Analysis Of X-Ray Images From Geological Materials

1990 ◽  
Vol 48 (2) ◽  
pp. 244-245
Author(s):  
J. M. Paque ◽  
R. Browning ◽  
P. L. King ◽  
P. Pianetta
Keyword(s):  
Quantitative Analysis ◽  
Bulk Composition ◽  
Principal Component ◽  
Analytical Description ◽  
Bulk Sample ◽  
Geological Samples ◽  
X Ray ◽  
Software And Hardware ◽  
And Storage ◽  
Insight Into

Geological samples typically contain many minerals (phases) with multiple element compositions. A complete analytical description should give the number of phases present, the volume occupied by each phase in the bulk sample, the average and range of composition of each phase, and the bulk composition of the sample. A practical approach to providing such a complete description is from quantitative analysis of multi-elemental x-ray images.With the advances in recent years in the speed and storage capabilities of laboratory computers, large quantities of data can be efficiently manipulated. Commercial software and hardware presently available allow simultaneous collection of multiple x-ray images from a sample (up to 16 for the Kevex Delta system). Thus, high resolution x-ray images of the majority of the detectable elements in a sample can be collected. The use of statistical techniques, including principal component analysis (PCA), can provide insight into mineral phase composition and the distribution of minerals within a sample.

EIS study of the corrosion behavior of an organic coating applied on Algerian oil tanker

2020 ◽  
Vol 117 (6) ◽  
pp. 610
Author(s):  
Nadia Hammouda ◽  
Kamel Belmokre
Keyword(s):  
Corrosion Protection ◽  
Electrochemical Impedance ◽  
Paint Film ◽  
Organic Coating ◽  
Diffusion Resistance ◽  
Double Layer Capacitance ◽  
Carbon Steel Surface ◽  
Chloride Environment ◽  
Oil Tanker ◽  
Epoxy Paint

Organic coatings are widely employed in the corrosion protection of most metal surfaces, particularly steel. They provide a barrier against corrosive species present in the environment, due to their high resistance to oxygen, water and ions transport. This study focuses on the evaluation of corrosion protection performance of epoxy paint on the carbon steel surface in chloride environment (3% NaCl) by Electrochemical Impedance Spectroscopy (EIS). The electrochemical behavior of painted surface was estimated by EIS parameters that contained paint film resistance, paint film capacitance and double layer capacitance. On the basis of calculation using EIS spectrums it was observed that pore resistance (Rpore) decreased with the appearance of doubled layer capacitance (Cdl) due to the electrolyte penetration through the film. This was further confirmed by the decrease of diffusion resistance (Rd) which was also the indicator of the deterioration of paint film protectiveness. Microscopic analyses have shown that oxidation dominates the corroded surfaces.

Experimental and Theoretical Comparable Study of Pure and Zinc Porphyrin Surface Modified ZnO Nanorod Arrays for Hybrid Solar Cell Applications

2020 ◽  
pp. 114-119
Keyword(s):  
Solar Cell ◽  
Electrochemical Impedance ◽  
Hybrid Solar Cell ◽  
Cell Performance ◽  
Solar Cell Performance ◽  
Solar Cell Efficiency ◽  
Cell Efficiency ◽  
Annealing Effects ◽  
Vertically Aligned ◽  
Surface Modified

Experimental and theoretical study Porphyrin-grafted ZnO nanowire arrays were investigated for organic/inorganic hybrid solar cell applications. Two types of porphyrin – Tetra (4-carboxyphenyle) TCPP and meso-Tetraphenylporphine (Zinc-TPP)were used to modify the nanowire surfaces. The vertically aligned nanowires with porphyrin modifications were embedded in graphene-enriched poly (3-hexylthiophene) [G-P3HT] for p-n junction nanowire solar cells. Surface grafting of ZnO nanowires was found to improve the solar cell efficiency. There are different effect for the two types of porphyrin as results of Zn existing. Annealing effects on the solar cell performance were investigated by heating the devices up to 225 °C in air. It was found that the cell performance was significantly degraded after annealing. The degradation was attributed to the polymer structural change at high temperature as evidenced by electrochemical impedance spectroscopy measurements.

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