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.

scholarly journals Method of diagnosing frequency dispersion parameters for transionospheric propagation of wideband signals using GLONASS/GPS technologies

2019 ◽  
Vol 30 ◽  
pp. 15008 ◽  
Author(s):  
Dmitry Ivanov ◽  
Aleksey Kislitsin ◽  
Maria Ryabova
Keyword(s):  
Measurement Error ◽  
Frequency Dispersion ◽  
Electron Content ◽  
Dispersion Correction ◽  
Dispersion Parameters ◽  
Total Electron ◽  
Stochastic Error ◽  
Communication Signal ◽  
Wideband Signals ◽  
Adaptive Correction

To solve the problem of adaptive correction for dispersion distortions of the characteristics of a wideband transionospheric channel, we developed a method of diagnosing frequency dispersion parameters using satellite data on the total electron content (TEC) of the ionosphere developed. It also considers TEC measurement stochastic error. For this reason, we performed an analysis of the limitation of the communication signal bandwidth for the case of dispersion correction with an error. It was found that the TEC measurement error that typically exists in practice allows us to spread signal bandwidth by up to three times.

Endothelial cell adhesion on polyelectrolyte multilayer films functionalised with fibronectin and collagen

2012 ◽  
Vol 66 (5) ◽  
Author(s):  
Nahla Zanina ◽  
Soumaya Haddad ◽  
Ali Othmane ◽  
Thierry Jouenne ◽  
David Vaudry ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Electrochemical Impedance ◽  
Colorimetric Assay ◽  
High Surface ◽  
Multilayer Films ◽  
Polyelectrolyte Multilayer ◽  
Adhesion Properties ◽  
Force Microscopy ◽  
Ohmic Resistance ◽  
Biomaterial Surfaces

AbstractThe seeding of endothelial cells on biomaterial surfaces has become a major challenge to achieve better haemocompatibility of these surfaces. Multilayers of polyelectrolytes formed by the layerby-layer method are promising in this respect. In this study, the interactions of endothelial cells with multilayered polyelectrolytes films were investigated. The build-ups were prepared by selfassembled alternatively adsorbed polyanions and polycations functionalised with fibronectin and collagen. Anionic poly(sodium 4-styrenesulfonate) and cationic poly(allylamine hydrochloride) polyelectrolytes were chosen as a model system. Elaborated surfaces were characterised by electrochemical impedance spectroscopy and cyclic voltammetry. The modified electrode showed good reversible electrochemical properties and high stability in an electrolyte solution. The film ohmic resistance was highest when the film was coated with fibronectin; the parameters so determined were correlated with atomic force microscopy images. Cell colorimetric assay (WST-1) and immunofluorescence were used to quantify the cell viability and evaluate the adhesion properties. When cultured on a surface where proteins were deposited, cells adhered and proliferated better with fibronectin than with collagen. In addition, a high surface free energy was favourable to adhesion and proliferation (48.8 mJ m−2 for fibronectin and 39.7 mJ m−2 for collagen, respectively). Endothelial cells seeded on functionalised-polyelectrolyte multilayer films showed a good morphology and adhesion necessary for the development of a new endothelium.

Dynamic trusted measurement model of operating system kernel

2013 ◽  
Vol 32 (4) ◽  
pp. 953-956 ◽  
Author(s):  
Si-yuan XIN ◽  
Yong ZHAO ◽  
Jian-hua LIAO ◽  
Ting WANG
Keyword(s):  
Operating System ◽  
Measurement Model

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.

The Effects of Cycling Rates and Cycling Temperature on the Battery Degradation in Vehicle-to-Grid Applications

2020 ◽  
Vol 12 (8) ◽  
pp. 1205-1212
Author(s):  
Peng Zhou ◽  
Shiran Luo ◽  
Xinzhou Li ◽  
Yitong Tan ◽  
Guangyu Cao ◽  
...  
Keyword(s):  
Environmental Temperature ◽  
Electrochemical Impedance ◽  
Lithium Ion ◽  
Negative Influence ◽  
Bet Surface Area ◽  
Vehicle To Grid ◽  
Battery Separator ◽  
Ohmic Resistance ◽  
Discharge Rates ◽  
Grid Applications

Commercial LiFePO4/graphite batteries produced by A123 Systems were cycled by simulating urban drive modes and vehicle-to-grid (V2G) modes at the 1 C and 2 C V2G discharge rates under 25 °C and 45 °C environmental temperature. Their degeneration was explored by characterization of capacity attenuation, electrochemical impedance spectroscopy (EIS), charge/discharge test of two half cells, BET Surface Area, XRD, FE-SEM and EDS. Results show that the capacity declines obviously with the rise of V2G discharge rates and environmental temperature. With the progress of the cycle test, the ohmic resistance (Rs) doesn't change a lot before the first 900 cycles and rises a great deal during the second 900 cycles while the resistance of charge transfer (Rct) is relatively low and the diffusion coefficient of lithium ion (DLi +) climbs up and then declines. Moreover, the rise of temperature and discharge rates mainly results in the increase of Rs. The degradation of battery separator arisen from the rise of V2G discharge rates and environmental temperature is one of reasons that the battery performance was reduced. The ascend of temperature makes a more negative influence on the attenuation of anodes than that of cathodes while the rise of V2G discharge rates has similar negative influence on the degradation of cathodes and anodes.

Full Parametric Characterization of LSM/LSM-YSZ Cathodes by Electrochemical Impedance Spectroscopy

2013 ◽  
Vol 11 (1) ◽  
Author(s):  
Rui Antunes ◽  
Janusz Jewulski ◽  
Tomasz Golec
Keyword(s):  
Layer Thickness ◽  
Electrochemical Impedance ◽  
Low Frequency ◽  
Contact Layer ◽  
Gas Diffusion ◽  
Impedance Spectra ◽  
Ohmic Resistance ◽  
The Individual ◽  
Ysz Electrolyte ◽  
Thickness Function

The contributions of the individual process steps of the cathode resistance were determined experimentally, directly from impedance spectra obtained from symmetrical cells. The symmetrical cells have architecture/structure consisting of YSZ electrolyte and a double layer cathode LSM-LSM/YSZ. The investigations were carried out in the temperature interval from 650 to 900 °C. The cathode processes steps activation energies obtained were 1.16 eV, 1.1 eV, and 0.09 eV (diffusion), respectively, which is in relatively good agreement with literature values. To understand the role of layer cathode thickness on electrochemical performance, electrical impedance spectra from symmetric LSM/YSZ/LSM cells were deconvoluted to obtain the key electrochemical components of electrode performance, namely ohmic resistance (RΩ), two low frequency processes related with chemical adsorption and dissociative reaction of O2 (Rp1 and Rp2), and bulk gas diffusion (W, finite warburg) through the electrode pores. The model used has Voight structure with three times constant. These parameters were then related to features, such as contact layer thickness, function layer thickness, and temperature. It was found that polarization resistance is highly dependent on the thickness of the contact layer (Rp1 and Rp2). All deconvoluted parameters are validated by using the appropriate physicochemical model.

A Method Used for Mechanism’s Motion Accuracy Reliability Analysis

2014 ◽  
Vol 945-949 ◽  
pp. 1069-1072
Author(s):  
Chang Li ◽  
Bing Chen Wang ◽  
Xing Han ◽  
Shuang Yi Zhang
Keyword(s):  
Reliability Analysis ◽  
Parametric Modeling ◽  
Dynamic Responses ◽  
Test Model ◽  
Large Sample ◽  
Virtual Test ◽  
Stochastic Error ◽  
Sample Data ◽  
Multi Body ◽  
Develop Program

Dynamic responses of a certain system could vary with the place, environment and time of use even if the system itself did not change. Traditionally, kinematical reliability analysis of a multi-body mechanism was a hard point in the reliability field. In order to obtain a large sample data of mechanism’s transient kinetic characteristics, it needed to take lots of time, labor and finance input to acquire. It reported an effective method used for mechanism kinetic reliability analysis, with the combination of VC++ and CAE software’s second develop program, it built a parametric virtual test model for complex mechanism system. Where, it used multiplicative congruent method to program a pseudo-random number function that conformed to normal distribution to simulate the stochastic error distribution of the mechanism, which was convenient for the Monte Carlo parametric modeling to obtain large sample data and calculate the system kinetic reliability.

scholarly journals A Reversible Protonic Ceramic Cell with Symmetrically Designed Pr2NiO4+δ-Based Electrodes: Fabrication and Electrochemical Features

2018 ◽  
Author(s):  
Artem Tarutin ◽  
Julia Lyagaeva ◽  
Andrey Farlenkov ◽  
Sergey Plaksin ◽  
Gennady Vdovin ◽  
...  
Keyword(s):  
High Efficiency ◽  
Materials Science ◽  
Electrochemical Impedance ◽  
Relaxation Times ◽  
Electrical Energy ◽  
Ohmic Resistance ◽  
Partial Pressures ◽  
Electrolytic Properties ◽  
Different Temperatures ◽  
And Performance

Reversible protonic ceramic cells (rPCCs) combine two different operation regimes, fuel and electrolysis modes, which allow reversible chemical-to-electrical energy conversion at reduced temperatures with high efficiency and performance. Here we present novel technological and materials science approaches, enabling a rPCC with symmetrical functional electrodes to be prepared using a single sintering step. The response of the cell fabricated on the basis of P–N–BCZD|BCZD|PBN–BCZD (where BCZD = BaCe0.5Zr0.3Dy0.2O3–δ, PBN = Pr1.9Ba0.1NiO4+δ, P = Pr2O3, N = Ni) is studied at different temperatures and water vapor partial pressures by means of volt-ampere measurements, electrochemical impedance spectroscopy and distribution of relaxation times analyses. The obtained results demonstrate that symmetrical electrodes exhibit classical mixed-ionic/electronic conducting behavior with no hydration capability at 750 °C; therefore, increasing the pH2O values in both reducing and oxidizing atmospheres leads to some deterioration of their electrochemical activity. At the same time, the electrolytic properties of the BCZD membrane are improved, positively affecting the rPCC’s efficiency. The electrolysis mode of the rPCC is found to be more efficient than the fuel cell mode under highly humidified atmospheres, since its performance is determined by the ohmic resistance, which decreases under respectively less humid conditions.

scholarly journals Creating and Preserving Nanoparticles during Co-Sintering of Solid Oxide Electrodes and Its Impact on Electrocatalytic Activity

Catalysts ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1073
Author(s):  
Sixbert P. Muhoza ◽  
Michael D. Gross
Keyword(s):  
Fuel Cell ◽  
Electrocatalytic Activity ◽  
Polarization Resistance ◽  
Electrochemical Impedance ◽  
Cell Polarization ◽  
Solid Oxide ◽  
Electrochemical Impedance Spectra ◽  
Ohmic Resistance ◽  
Oxide Electrodes ◽  
Novel Processing

A novel processing method that creates and preserves ceramic nanoparticles in solid oxide electrodes during co-sintering at traditional sintering temperatures is introduced. Specifically, carbon templated samarium-doped ceria nanoparticles (nSDC) were successfully integrated with commercial lanthanum strontium cobalt ferrite (LSCF) and commercial SDC powders, producing LSCF-SDC-nSDC cathodes upon processing. The effect of nSDC concentration on cathode electrocatalytic activity was investigated at low operational temperatures, 600 °C–700 °C, with symmetrical cells. Low nSDC loadings, ≤5 wt% nSDC, significantly decreased cell polarization resistance whereas higher loadings increased it. The best electrochemical performance was achieved with 5 wt% nSDC, lowering the polarization resistance by 41% at 600 °C. Fuel cell tests demonstrate that adding 5 wt% nSDC increased the maximum fuel cell power density by 38%. Electrochemical impedance spectra showed substantial improvements in both fuel cell polarization resistance and ohmic resistance, indicating that nSDC increased the electrocatalytically active area of the cathode. This work demonstrates a simple, novel method for effectively increasing electrocatalytic activity of solid oxide electrodes at low operational temperatures.

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