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This experimental study focuses on the corrosion behavior of aluminum alloys in hydrogen sulfide (H2S) gas and liquid phases. The corrosion behaviors of 3A21, 6061, and 6063 aluminum alloys are investigated via scanning electron microscopy, energy dispersive spectroscopy, and thermogravimetry-differential scanning calorimetry. The results show that the corrosion rates of the three types of aluminum alloys increase with temperature, and the slope of the corrosion rate curve decreases gradually after reaching a certain temperature. At 75 °C, the corrosion rate reached 0.0675 mm/a, 0.0881 mm/a and 0.0613 mm/a in the gas phase, respectively. The corrosion products show white-yellow-gray irregular pits and a honeycomb-like morphology, and the main components are aluminum hydroxide, alumina, and aluminum sulfide. In particular, the 6061 aluminum alloy presents the most severe corrosion in H2S gas. Compared with the H2S gas phase, the corrosion rate in the liquid phase is higher. Additionally, the irregular pitting and honeycomb-like morphologies are more evident. Corrosion becomes more significant as temperature increases. Although the corrosion products in the two phases are composed of the same components, the content in the liquid phase is higher. The heat absorption and mass loss of the corrosion products present the same regularity. This indicates that the corrosion of the H2S liquid phase on the aluminum alloy is more significant than that of the H2S gas phase. [ABSTRACT FROM AUTHOR]

To understand the overpressure transient and flame behavior of CH4/air premixed gas explosion venting in the presence of porous materials, a series of explosion venting tests is conducted in a spherical vessel with a neck. The effects of pore size, porosity, thickness, and properties of porous material on Pstat, Pred, Pburst, and Pext are measured using pressure transmitters, and the image of an exploding venting jet flame passing through porous materials is captured using a high-speed camera. It is shown that the pressure wave at the high-pressure side of the explosion vent is in a critical state when the venting burst membrane ruptures without the porous materials, and the vented jet is confirmed to be under-expanded. The addition of porous materials does not significantly affect Pstat but results in the highest Pburst in porous material Al2O3 50PPI and the highest Pred in porous material SiC 20PPI. This is consistent with the assumption that Pred > Pburst, and that an increase in Pburst corresponds to a decrease in Pred. In addition, Pext is more likely to occur at a position 250–350 mm away from the vent, and as the thickness of the porous materials increases, the possibility of an external explosion overpressure will increase. Moreover, the porous material significantly affects the venting jet flame, and as the thickness of the porous material increases, the shape of the venting jet flame resembles that of a "broom," owing to the dynamic overpressure generated from the flame-porous material interaction. [ABSTRACT FROM AUTHOR]

In a Wistar rat model, prolonged supplementation of mustard seed (MS) to the diet significantly ameliorates the induction of colorectal carcinomas by 1,2-dimethylhydrazine (DMH). The expression of the splenocyte major histocompatibility complex class I (MHCI) was found significantly enhanced, whereas that of the major histocompatibility complex class II (MHCII) was significantly decreased. Compared to that of control animals, the proportion of spleenic B- and dendritic cells (DC) was amplified in the MS group. The expressions of MHCI, as well as that of MHCII, were increased in DC cells; whereas in B cells, MHCI expression was augmented but that of MHCII moderately decreased. The percentages of CD8+CD28+ and CD4+CD28+ cells were increased in the MS group, while the CD4+CD25+Foxp3+ subset was depressed. Plasma analysis showed that DMH-exposure induced amplified amounts of interleukin (IL)-4, IL-5, IL-10, and transforming growth factor-beta, whereas MS feeding counteracted this effect but enhanced IL-2, IL12p70, IL21, TNF-alpha, and interferon-gamma. In the SW480 colon adenocarcinoma cell-line, the cytotoxicity of spleenic T-cells from MS-fed animals was significantly increased. In the DMH-exposed rats, the expression of perforin in the spleenic T-cells was dramatically decreased, whereas MS abolished this depression. In summary, dietary MS suppresses DMH-induced immuno-imbalance as well as colon carcinogenesis in rats. [ABSTRACT FROM AUTHOR]