Measurement Technique of Effective Oxygen Diffusion-Coefficient of Water-Containing Gas Diffusion Layers

2017 ◽  
Vol 80 (8) ◽  
pp. 113-121
Author(s):  
Ryosuke Hori ◽  
Ikuyasu Kato ◽  
Atsushi Ida ◽  
Atsushi Yamamoto ◽  
Yuki Sano
Keyword(s):  
Diffusion Coefficient ◽  
Measurement Technique ◽  
Oxygen Diffusion ◽  
Gas Diffusion ◽  
Gas Diffusion Layers ◽  
Oxygen Diffusion Coefficient ◽  
Diffusion Layers

scholarly journals Assessment of Electrical Resistivity and Oxygen Diffusion Coefficient of Cementitious Materials from Microstructure Features

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3141
Author(s):  
Renzhan Zhou ◽  
Qiang Li ◽  
Jiandong Wang ◽  
Kewen Zhou ◽  
Rui He ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Diffusion Coefficient ◽  
Oxygen Diffusion ◽  
Cement Mortar ◽  
Resistivity Measurement ◽  
Cementitious Materials ◽  
Gas Diffusion ◽  
Electrical Resistivity Measurement ◽  
Capillary Porosity ◽  
Oxygen Diffusion Coefficient

A newly proposed modified non-contact electrical resistivity measurement was used to test the resistivity of concrete and cement mortar. The oxygen diffusion coefficients of concrete and mortar were determined by a gas diffusion measurement, and the capillary porosity of concrete and cement mortar was measured by mercury intrusion porosimetry (MIP) measurement. The obtained electrical resistivity and capillary porosity results were verified with other researchers’ data, the measured electrical resistivity results can be estimated by a simple equation from the capillary porosity results. The obtained oxygen diffusion coefficient results were quantitatively correlated with capillary porosity and electrical resistivity measurement results. The proposed equations can be practically used to assess the electrical resistivity and oxygen diffusion coefficient.

Use of a dynamic gassing-out method for activity and oxygen diffusion coefficient estimation in biofilms

1998 ◽  
Vol 37 (4-5) ◽  
pp. 171-175
Author(s):  
Artem Khlebnikov ◽  
Falilou Samb ◽  
Paul Péringer
Keyword(s):  
Diffusion Coefficient ◽  
Oxygen Uptake ◽  
Oxygen Diffusion ◽  
Fixed Bed ◽  
Biofilm Reactor ◽  
Strictly Aerobic ◽  
Comamonas Testosteroni ◽  
Respiration Activity ◽  
Oxygen Diffusion Coefficient ◽  
Biofilm Development

p-toluenesulphonic acid degradation by Comamonas testosteroni T-2 in multi-species biofilms was studied in a fixed bed biofilm reactor. The polypropylene static mixer elements (Sulzer Chemtech Ltd., Switzerland) were used as a support matrix for biofilm formation. Biofilm respiration was estimated using the dynamic gassing-out oxygen uptake method. A strong relation between oxygen uptake and reactor degradation efficiency was observed, because p-toluenesulphonate degradation is a strictly aerobic process. This technique also allowed us to estimate the thickness of the active layer in the studied system. The mean active thickness was in order of 200 μm, which is close to maximum oxygen penetration depth in biofilms. A transient mathematical model was established to evaluate oxygen diffusitivity in non-steady-state biofilms. Based on the DO concentration profiles, the oxygen diffusion coefficient and the maximum respiration activity were calculated. The oxygen diffusion coefficient obtained (2 10−10-1.2 10−9 m2 s−1) is in good agreement with published values. The DO diffusion coefficient varied with biofilm development. This may be, most likely, due to the biofilm density changes during the experiments. The knowledge of diffusivity changes in biofilms is particularly important for removal capacity estimation and appropriate reactor design.

Imaging of desaturation of the frozen gas diffusion layers by synchrotron X-ray radiography

2021 ◽  
Author(s):  
Yuzhou Zhang ◽  
Viral Hirpara ◽  
Virat Patel ◽  
Chen Li ◽  
Ryan Anderson ◽  
...  
Keyword(s):  
Gas Diffusion ◽  
Gas Diffusion Layers ◽  
X Ray ◽  
Diffusion Layers
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