Electrochemical impedance spectroscopy (EIS) was applied to evaluate corrosion rates of steels covered with a thin electrolyte film. A two-electrode cell consisting of a pair of identical steel plates embedded in epoxy resin was used for the EIS measurements under the thin electrolyte film. A transmission line type equivalent circuit was employed to describe the EIS behavior. Using this method, a charge transfer resistance was successfully estimated under uneven current distributions. This technique was applied to estimate the corrosion rates of steels under electrolyte film thickness in a range of 5 μm to 1 mm.

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Electrolyte film thickness, X f / µm Figure 7. Plots of corrosion rates i corr of carbon steel covered with a 2 M NaNO 3 electrolyte layer as a function of the thickness of the electrolyte film. The i corr was calculated by Eq. 13 using the charge transfer resistance, R ct , obtained from curve-fitting to TML equivalent circuit and impedance at 10 mHz, Z 10mHz .On page C139, the Conclusions section should read: An EIS measurement system has been established under a thin electrolyte film. The EIS can be successfully curve fitted by a TML equivalent circuit. The method to accurately determine the parameters in the TML equivalent circuit was proposed. This method was applied to carbon steel corrosion under ultrathin electrolyte films of 5-25 μm, and it was found that the corrosion rate shows a maximum value when the thickness is approximately 20 μm.) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 52.41.17.47 Downloaded on 2018-05-07 to IP

A large number of temporary housings (THs) were used in the Yanqing zone of the Beijing 2022 Olympic and Paralympic Winter Games. Taking a kind of container house (CH) used in Yanqing zone as a model, the objective of this paper is to analyze the effect of insulation thickness on heating energy consumption and corresponding carbon emission. The effect of service life of THs on economic thickness was also discussed. The simulation model was developed using EnergyPlus and the heating energy consumption with different insulation materials was simulated based on the meteorological parameters of the top of Xiaohaituo Mountain (2177.5 m) and the Olympic/Paralympic Village (950 m) in Yanqing zone. In the simulation process, the thermal insulation performance of the CH was enhanced with reference to the requirements of GB/T 51350-2019 Technical Standard for Nearly Zero Energy Buildings (NZEB) on one hand. Additionally, the insulation performance was evaluated in terms of payback period and carbon emission. On the other hand, the economic thickness of different insulation materials (rock wool (RW), extruded polystyrene (XPS), polyurethane (PU)) and the high performance vacuum insulation panel (HVIP)) for different service lives of CH was studied. Results show that the U-values of the envelope meeting the NZEB standard can decrease approximately 21.4–32.8% of the heating energy consumption, compared with the original envelope. When the service life of CH is extended to 20 years, the carbon emission is reduced by 18.5% and 29.5%. The payback period of HVIP is longest, up to 31.4 a, and the results of economic thickness show that when the service life of the CH ranges from 1 year to 20 years, the economic thickness range of RW is 47–235 mm, XPS is 41–197 mm, PU is 33–149 mm and HVIP is 4–18 mm at the altitude of 2177.5 m. At the altitude of 950 m, the economic thickness range of RW is 28–158 mm, XPS is 26–131 mm, PU is 25–118 mm, and HVIP is 2–12 mm. From an economic point of view, the service life of a CH has a significant impact on the choice of insulation thickness.

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