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971.
Faiza Zafar Humaira Bano Azhar Mahmood Francisco Corvo Joelis Rodriguez 《工业材料与腐蚀》2020,71(9):1557-1575
This paper has reported physicochemical features of mild steel's corrosion products and provided atmospheric corrosivity maps of Karachi harbor city, drafted on the basis of spatial distribution of corrosion data from July 2018 to June 2019 at 10 different urban, industrial, and marine test sites. Exposure tests have been performed to study atmospheric corrosivity, corrosion products, and corrodants including chloride, sulfur dioxide, time of wetness (TOW), and corrosion rate as per ISO and ASTM standards. Scanning electron microscope, Fourier-transform infrared spectroscopy, and X-ray diffraction have corroborated the presence of lepidocrocite, goethite, magnetite, and quartz phases at almost all the test sites, with slight variations in their morphologies and quantities. The data analysis has revealed that TOW is a major detrimental factor to accelerate corrosion of mild steel at Karachi city. The corrosivity category of all urban and marine test sites is found in C4–C5 range, whereas for industrial test sites, it is found in C3–C5 range. Resultant corrosivity maps have shown that the prevailing atmosphere is significantly corrosive at Karachi harbor city. This study has furnished a novel product of atmospheric corrosivity map, which is the first-ever corrosivity map for Pakistan. 相似文献
972.
Lisa C. Klein Kutaiba Al-Marzoki Andrei Jitianu Gabriela Rodriguez 《Journal of the American Ceramic Society》2020,103(8):4140-4149
To increase the connectivity of the molecular structure but not to prevent softening, small amounts of tetraethoxysilane (TEOS) were added to phenyl-substituted melting gels. The limit of the additions was determined when the melting gel lost its ability to soften. A comparison was made between TEOS diluted with ethanol, TEOS diluted with methanol, and tetramethoxysilane (TMOS) diluted with methanol. The additions had slight effects on the glass transition behavior, the gelling time and the indentation hardness. The role of the TEOS was both a form of dilution and a cross-linking promoter. 相似文献
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J. Ramiro Rodriguez Ruvalcaba Brigitte Caussat Merhdji Hemati Jean-Pierre Couderc 《加拿大化工杂志》1999,77(1):35-44
After having analyzed the few literature results concerning fluidized beds hydrodynamics under reduced pressure, new theoretical elements are proposed which provide an estimation of the beginning and finishing fluidization velocities. Numerous experimental results(Umfapp, Umb, Ump, ?mf, ?mb, ?mp), obtained at 20 and 500°C, are then presented for several sub-atmospheric pressures. Finally, f& the first time, at leastto our knowledge, by high frequency recording pressure drops through the bed, the influence of pressure decreases on the hydrodynamics is accurately analyzed. 相似文献
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