Characterization and Fuel Cell Testing of Radiation-Grafted Psi Membranes

1999 ◽  
Vol 575 ◽  
Author(s):  
H.-P. Brack ◽  
M. M. Koebel ◽  
A. Tsukada ◽  
J. Huslage ◽  
F. Buechi ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Oxidative Stability ◽  
Screening Method ◽  
Exchange Capacity ◽  
Ex Situ ◽  
Active Area ◽  
Rapid Screening ◽  
Raman Spectroscopic ◽  
Current Voltage

ABSTRACTWe have demonstrated earlier the useful performance of our PSI radiation-grafted membranes in terms of the current-voltage characteristics of 30 cm2 active area fuel cells containing these membranes and their long-term testing over 6,000 h at 60 °C. We report here on testing of PSI radiation-grafted membranes in these fuel cells at 80 °C and in short stacks comprised of two or four 100 cm2 active area cells. The in-situ degradation of membranes has been investigated by characterizing membranes both before testing in fuel cells and post-mortem after testing in fuel cells. Characterization was accomplished by means of ion-exchange capacity and infrared and Raman spectroscopic measurements. In addition, a rapid screening method for our ex-situ testing of the oxidative stability of proton-conducting membranes was developed in this work. Comparison of the initial screening test results concerning the oxidative stability of some perfluorinated, partially-fluorinated, and non-fluorinated membranes compare well qualitatively with the relative stability of these same membranes during their long-term testing in fuel cells.

Performance Characteristics of Solid Oxide Fuel Cells with YSZ/CGO Electrolyte

2017 ◽  
Vol 743 ◽  
pp. 281-286 ◽  
Author(s):  
Anastasya N. Kovalchuk ◽  
Alexey M. Lebedinskiy ◽  
Andrey A. Solovyev ◽  
Igor V. Ionov ◽  
Egor A. Smolyanskiy ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Screen Printing Method ◽  
Power Characteristics ◽  
Long Term Stability ◽  
Current Voltage ◽  
Bilayer Electrolyte

This paper presents the results of performance evaluation of anode-supported solid oxide fuel cells (SOFC) with magnetron sputtered YSZ/CGO bilayer electrolyte, and composite LSCF-CGO cathode. Deposition of the YSZ/CGO electrolyte with the thickness of up to 14 microns was performed on the commercial anode substrates with dimensions of 5×5 cm2. The LSCF-CGO cathode of the fuel cells was formed by the screen-printing method. The microstructure of the YSZ/CGO bilayer electrolyte and LSCF-CGO cathode was studied by scanning electron microscopy. Comparison of the fuel cells performance with different thicknesses of the YSZ and CGO layers was carried out by measuring current-voltage and power characteristics, and also by testing the long-term stability of cell power at the temperature of 750 °C and voltage of 0.7 V.

Positive charge discovered across Western Australian wheatbelt soils challenges key soil and nitrogen management assumptions

Soil Research ◽  
2009 ◽  
Vol 47 (1) ◽  
pp. 127 ◽  
Author(s):  
M. T. F. Wong ◽  
K. Wittwer
Keyword(s):  
Nitrate Leaching ◽  
Positive Charge ◽  
Screening Method ◽  
Clay Mineralogy ◽  
Exchange Capacity ◽  
Nitrogen Management ◽  
Rapid Screening ◽  
Application Rates ◽  
Fertiliser Application ◽  
Highly Weathered Soils

Nitrogen management in Western Australia (WA) and in cropping areas elsewhere in Australia assumes that soil contains negligible or no positive charge and is therefore unable to retain nitrate against leaching. The amount of water needed to displace nitrate is thus assumed to be the drainable volume of water held by the soil (1 pore volume), and in sandy soils about 100 mm drainage is assumed to be required to displace nitrate by 1 m. The clay mineralogy of the highly weathered soils of the WA wheatbelt is dominated by kaolinite and iron and aluminium oxides. This mineralogy suggests likely occurrence of positive charge and anion exchange capacity (AEC), since these minerals can carry positive charge under normal acidic field situations. We measured AEC of soils sampled widely across the WA wheatbelt by independent leaching and batch equilibration methods of charge measurement. This showed widespread occurrence of positive charge and AEC in these soils. AEC ranged from 0 to 2.47 mmolc/kg and is linearly correlated with the potassium chloride or monocalcium phosphate extractable sulfate content of the soil. This correlation provides a rapid screening method to identify soils with positive charge. Application of ion-chromatographic theory showed that AEC has a large effect in delaying nitrate leaching by up to 12.5 pore volumes. The most highly charged soil (2.47 mmolc/kg) thus needed 12.5 times more water to displace nitrate than currently assumed. This potentially large delay in nitrate leaching affects the optimum amount and time of fertiliser application, rates of soil acidification attributed to nitrate leaching and the benefit of ameliorating subsoils to allow roots access to subsoil water and leached nitrate. It also calls into question the use of anions such as bromide to trace water flow and estimate recharge in these soils.

scholarly journals Computational engineering of the oxygen electrode-electrolyte interface in solid oxide fuel cells

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Kaiming Cheng ◽  
Huixia Xu ◽  
Lijun Zhang ◽  
Jixue Zhou ◽  
Xitao Wang ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Microstructure Evolution ◽  
Oxygen Electrode ◽  
Solid Oxide ◽  
Ohmic Loss ◽  
Oxide Fuel ◽  
Computational Engineering ◽  
Electrolyte Interface

AbstractThe Ce0.8Gd0.2O2−δ (CGO) interlayer is commonly applied in solid oxide fuel cells (SOFCs) to prevent chemical reactions between the (La1−xSrx)(Co1−yFey)O3−δ (LSCF) oxygen electrode and the Y2O3-stabilized ZrO2 (YSZ) electrolyte. However, formation of the YSZ–CGO solid solution with low ionic conductivity and the SrZrO3 (SZO) insulating phase still happens during cell production and long-term operation, causing poor performance and degradation. Unlike many experimental investigations exploring these phenomena, consistent and quantitative computational modeling of the microstructure evolution at the oxygen electrode–electrolyte interface is scarce. We combine thermodynamic, 1D kinetic, and 3D phase-field modeling to computationally reproduce the element redistribution, microstructure evolution, and corresponding ohmic loss of this interface. The influences of different ceramic processing techniques for the CGO interlayer, i.e., screen printing and physical laser deposition (PLD), and of different processing and long-term operating parameters are explored, representing a successful case of quantitative computational engineering of the oxygen electrode–electrolyte interface in SOFCs.

Sources and prevention of graft infection during long term ex situ liver perfusion

2021 ◽  
Author(s):  
Dilmurodjon Eshmuminov ◽  
Matteo Mueller ◽  
Silvio D. Brugger ◽  
Lucia Bautista Borrego ◽  
Dustin Becker ◽  
...  
Keyword(s):  
Liver Perfusion ◽  
Graft Infection ◽  
Ex Situ

scholarly journals Electrocardiogram lead selection for intelligent screening of patients with systolic heart failure

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yu-An Chiou ◽  
Jhen-Yang Syu ◽  
Sz-Ying Wu ◽  
Lian-Yu Lin ◽  
Li Tzu Yi ◽  
...  
Keyword(s):  
Heart Failure ◽  
Low Cost ◽  
Screening Method ◽  
Systolic Heart Failure ◽  
Rapid Screening ◽  
Ecg Signals ◽  
Testing Dataset ◽  
Lead Selection ◽  
Ecg Leads ◽  
Intelligent Screening

AbstractElectrocardiogram (ECG)-based intelligent screening for systolic heart failure (HF) is an emerging method that could become a low-cost and rapid screening tool for early diagnosis of the disease before the comprehensive echocardiographic procedure. We collected 12-lead ECG signals from 900 systolic HF patients (ejection fraction, EF < 50%) and 900 individuals with normal EF in the absence of HF symptoms. The 12-lead ECG signals were converted by continuous wavelet transform (CWT) to 2D spectra and classified using a 2D convolutional neural network (CNN). The 2D CWT spectra of 12-lead ECG signals were trained separately in 12 identical 2D-CNN models. The 12-lead classification results of the 2D-CNN model revealed that Lead V6 had the highest accuracy (0.93), sensitivity (0.97), specificity (0.89), and f1 scores (0.94) in the testing dataset. We designed four comprehensive scoring methods to integrate the 12-lead classification results into a key diagnostic index. The highest quality result among these four methods was obtained when Leads V5 and V6 of the 12-lead ECG signals were combined. Our new 12-lead ECG signal–based intelligent screening method using straightforward combination of ECG leads provides a fast and accurate approach for pre-screening for systolic HF.

“Synthesis of coagulation factors during long‐term ex situ liver perfusion”

2021 ◽  
Author(s):  
Dilmurodjon Eshmuminov ◽  
Max Hefti ◽  
Matteo Mueller ◽  
Martin J. Schuler ◽  
Lucia Bautista Borrego ◽  
...  
Keyword(s):  
Liver Perfusion ◽  
Coagulation Factors ◽  
Ex Situ
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