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This paper investigates the high temperature resistance performance and mechanism of potassium-activated blended precursor geopolymer with silica fume. The failure morphology, volume, and mass loss, compressive strength deterioration, hydration production, and pore structure are measured and analyzed. The results show that introducing slag into fly ash-based geopolymer could greatly improve the 28 d compressive strength but reduce the thermal stability. In contrast, the partial substitution of fly ash by metakaolin contributes to excellent high temperature resistance with slightly enhanced 28 d compressive strength. After being exposed at 800 °C, the residual compressive strength of F7M3 remains at 37 MPa, almost 114% of the initial ambient-temperature strength. An appropriately enlarged silica fume content in geopolymer results in increased compressive strength and enhanced thermal stability. However, an excessive silica fume content is detrimental to the generation of alkali-aluminosilicate gels and ceramic-like phases and thus exacerbates the high temperature damage. [ABSTRACT FROM AUTHOR]

This article reported the electrochemical deposition of polyaniline (PANI) on 316-L stainless steel (316LSS) to improve the anti-corrosion performance as PEMFC metal bipolar plates. The results indicate that PANI can increase the corrosion potential of 316LSS by more than 410.57 mV and effectively decrease the corrosion current density by four orders of magnitude in comparison with the uncoated 316LSS. The experimental results showed that the PANI increased the open-circuit potential of the steel by about 140 mV. The polarization current value of PANI-coated 316LSS reduced to 2.3 × 10−7 A/cm2 under the PEMFC cathode working condition. During exposure for 12 h, Nyquist plots of PANI-coated 316LSS did not change substantially. This indicates that the PANI coating was an effective barrier against the inward penetration of corrosive species. [ABSTRACT FROM AUTHOR]

In this paper, onsite measurements and a subjective questionnaire were conducted to study the thermal environment and heating condition of bedrooms during the winter in rural areas in China's hot summer and cold winter (HSCW) region. Indoor and outdoor thermal environmental parameters were measured to evaluate the thermal conditions of bedrooms. Thermal sensation/tendency/acceptance, heating, and health condition were investigated to complete the analysis of attitudes of local residents on the thermal environment of bedrooms, heating and health issues, as well as the analysis of buildings. The observed results demonstrate that occupants in this region have a strong tolerance to low-temperature environments with the 80% acceptable lower temperature of 4.7 °C and a neutral temperature of 10.7 °C, with an average clothing insulation over 2.2 clo. Oversized volume and acreage of buildings and windows induce a lower temperature in the bedroom. Infants have a significant effect on heating requirements, including heating duration and temperature setpoint. Local residents are highly concerned about the costs, safety, and health related to heating and thermal environments. All evidence obtained through this investigation shows that it is beneficial to formulate regulations for the shape, envelope, and centralized heating policy for rural residential buildings in the HSCW region. [ABSTRACT FROM AUTHOR]