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About: Rust is a(n) research topic. Over the lifetime, 8946 publication(s) have been published within this topic receiving 79850 citation(s). The topic is also known as: iron corrosion & iron weathering.

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TL;DR: Pathogenicity of Pgt-Ug99 was studied in seedling tests of available wheats containing Sr31, as well as other stem rust differential lines, and Virulence to the T. ventricosum-derived gene Sr38, which is linked to Lr37 and Yr17 and occurs in cultivars from Australia, the United Kingdom, and the United States, was not known previously.
Abstract: In much of the world, resistance to stem rust in wheat, caused by Puccinia graminis f. sp. tritici, is based at least in part on the gene Sr31. During February 1999, high levels of stem rust infection were observed on entries in wheat (Triticum aestivum) grown in a nursery at Kalengyere Research Station in Uganda. Because several of the rusted entries were known to carry the 1BL-1RS chromosome translocation containing the Sr31, Lr26, and Yr9 genes for rust resistance, virulence to Sr31 was suspected. Urediniospores, collected in bulk from rusted stems of seven entries containing Sr31, were suspended in light mineral oil and sprayed on primary leaves of 7-day-old seedlings of South African wheat cv. Gamtoos (=Veery #3, pedigree: Kvz/Buho‘S’//Kal/BB). Plants were kept overnight at 19 to 21°C in a dew chamber before placement in a greenhouse at 18 to 25°C. After ≈14 days, urediniospores were collected from large, susceptible-type stem rust pustules and subsequently increased on Gamtoos, which served as a sel...

549 citations

Journal ArticleDOI
Abstract: For fundamental studies of the atmospheric corrosion of steel, it is useful to identify the iron oxide phases present in rust layers. The nine iron oxide phases, iron hydroxide (Fe(OH)2), iron trihydroxide (Fe(OH)3), goethite (α-FeOOH), akaganeite (β-FeOOH), lepidocrocite (γ-FeOOH), feroxyhite (δ-FeOOH), hematite (α-Fe2O3), maghemite (γ-Fe2O3) and magnetite (Fe3O4) are among those which have been reported to be present in the corrosion coatings on steel. Each iron oxide phase is uniquely characterized by different hyperfine parameters from Mossbauer analysis, at temperatures of 300K, 77K and 4K. Many of these oxide phases can also be identified by use of Raman spectroscopy. The relative fraction of each iron oxide can be accurately determined from the Mossbauer subspectral area and recoil-free fraction of each phase. The different Mossbauer geometries also provide some depth dependent phase identification for corrosion layers present on the steel substrate. Micro-Raman spectroscopy can be used to uniquely identify each iron oxide phase to a high spatial resolution of about 1 µm.

465 citations

Journal ArticleDOI
TL;DR: Results clearly indicate that U(VI) (as soluble uranyl ion) is readily reduced by green rust to U(IV) in the form of relatively insoluble UO2 nanoparticles, suggesting that the presence of green rusts in the subsurface may have significant effects on the mobility of uranium, particularly under iron-reducing conditions.
Abstract: Green rusts, which are mixed ferrous/ferric hydroxides, are found in many suboxic environments and are believed to play a central role in the biogeochemistry of Fe. Analysis by U LIII-edge X-ray absorption near edge spectroscopy of aqueous green rust suspensions spiked with uranyl (UVI) showed that UVI was readily reduced to UIV by green rust. The extended X-ray absorption fine structure (EXAFS) data for uranium reduced by green rust indicate the formation of a UO2 phase. A theoretical model based on the crystal structure of UO2 was generated by using FEFF7 and fitted to the data for the UO2 standard and the uranium in the green rust samples. The model fits indicate that the number of nearest-neighbor uranium atoms decreases from 12 for the UO2 structure to 5.4 for the uranium-green rust sample. With an assumed four near-neighbor uranium atoms per uranium atom on the surface of UO2, the best-fit value for the average number of uranium atoms indicates UO2 particles with an average diameter of 1.7 ± 0.6 nm....

409 citations

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