The role of two oxygen sources, and water vapor, in the initiation KCl-induced high-temperature corrosion was addressed by studying high-alloyed commercial materials at 550 °C. differentiation between sources implemented with 18O-enriched 16O2. Based on results, solid-solid reaction KCl(s) protective oxide alloy surface appeared to be more responsible for than gas-solid KCl(g) oxide. Water invo...

tourmalinization characterizes the most pervasive alteration type in the nezam abad ore deposit, west-central iran. it delineates high-temperature centers of mineralization and together with quartz and cassiterite form inner parts of the alteration halo. the composition of tourmalines plots mostly along and between the proton and alkali-deficient end members. tourmaline in quartzdioritic host i...

[18F]Fluoride was trapped from [18O]water in high yield by ion exchange on a microporous carbon prepared by controlled oxidation to produce a cationic surface with an exchange capacity of about 350 microequiv/g. The [18F]fluoride could be recovered by displacement with aqueous K2CO3. The cationic carbon offered a dimensionally rigid matrix of high thermal stability. It was characterized with re...

Oxidation of p-coumarate at the ortho-position is a key step to form umbelliferone. A tracer analysis using (18)O2 was performed in order to take information about the formation of umbelliferone in the root tissue of sweet potato. Mass fragmentation experiments revealed incorporation of an 18O atom into the 1-position of umbelliferone. This result indicates that the lactone of umbelliferone is ...

The reaction of hypochlorous acid (HOCl) with hydrogen peroxide is known to generate stoichiometric amounts of singlet molecular oxygen [O2 (1Deltag)]. This study shows that HOCl can also react with linoleic acid hydroperoxide (LAOOH), generating O2 (1Deltag) with a yield of 13 +/- 2% at physiological pH. Characteristic light emission at 1,270 nm, corresponding to O2 (1Deltag) monomolecular dec...

The influence of metal cations on 13C-18O bonds in carbonates is still under debate. This paper used ab initio method to investigate this kind of influence of Mg2+, Fe2+ and Zn2+ cations on 13C-18O bonds in precipitated aragonite, calcite and dolomite. The polynomials of ∆47 and reduced partition function ratios (RPFRs) for 13/12C, 14/12C and 18/16O of these minerals were given within temperatu...

Water-use efficiency and stable isotope composition were studied in three tropical tree species. Seedlings of Tectona grandis, Swietenia macrophylla and Platymiscium pinnatum were grown at either high or low water supply, and with or without added fertilizer. These three species previously exhibited low, intermediate and high whole-plant water-use efficiency (TE) when grown at high water supply...