2,753 research outputs found

    Bioavailable Iron in Equatorial Pacific Ocean Aerosol Samples

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    Oceanic iron (Fe) fertilization experiments performed in remote regions have established that Fe additions draw carbon into the ocean, at least over the months-long time frame of the experiments. However, the mechanisms that control Fe speciation in atmospheric aerosol particles before and after deposition into the surface ocean remain largely unknown. This is in part due to the analytical challenge of quantifying Fe at environmentally significant sub-nano molar levels. The flow injection analysis method combined with the luminol chemiluminescence analytical system allows us to explore the near-real time determination of pico-molar levels of both Fe(II) and H2O2 produced from real marine aerosol particles collected over the Equatorial Pacific Ocean, as a function of both sunlight and electron donors (EDs) such as dimethyl sulfide and organic acids. Detection limits were as low as 40 pM Fe(II) and 100 pM H2O2. Fe(II)in aerosol concentration was found to be 0.29 ± 1.48 pg m-3 in large, 19.14 ± 18.31 pg m-3 in coarse, 38.80 ± 37.87 pg m-3 in fine, and 43.61 ± 42.93 pg m-3 in ultrafine size aerosol samples. A typical analysis of photochemical reaction with addition of EDs can be performed in five minutes. Results indicate that Fe(III) is reduced in the presence of light with ED that are already present in the collected aerosols, the external additions of ED have an enhancing effect in some of the samples, and the Fe(II) concentration shows positive corrected to non-sea-salt sulfate (NSS-SO42-) and some other anions. Fe(II) is found to be 3% of total Fe in the aerosols. These results contribute to resolving current inconsistencies in chemical models on the speciation of Fe and sulfur cycles in the marine atmosphere

    Hydrocarbon fuel additives and method for preparing same

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    A compound having the general formula R*COH[- CORJj,, wherein R is a lower alkyl hydrocarbon radical, y is 0 or 1, and x is 2 when y is 1 and 3 when y is 0, is prepared by admixing carbon monoxide, a transition metal halide, and an organomonolithium compound or an anionic equivalent thereof.https://digitalcommons.mtu.edu/patents/1100/thumbnail.jp

    ηc\eta_c mixing effects on charmonium and BB meson decays

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    We include the ηc\eta_c meson into the η\eta-η′\eta'-GG mixing formalism constructed in our previous work, where GG represents the pseudoscalar gluball. The mixing angles in this tetramixing matrix are constrained by theoretical and experimental implications from relevant hadronic processes. Especially, the angle between ηc\eta_c and GG is found to be about 11∘11^\circ from the measured decay widths of the ηc\eta_c meson. The pseudoscalar glueball mass mGm_G, the pseudoscalar densities mqq,ss,ccm_{qq,ss,cc} and the U(1) anomaly matrix elements associated with the mixed states are solved from the anomalous Ward identities. The solution mG≈1.4m_G\approx 1.4 GeV obtained from the η\eta-η′\eta'-GG mixing is confirmed, while mqqm_{qq} grows to above the pion mass, and thus increases perturbative QCD predictions for the branching ratios Br(B→η′K)Br(B\to\eta'K). We then analyze the ηc\eta_c-mixing effects on charmonium magnetic dipole transitions, and on the B→η(′)KSB\to\eta^{(\prime)}K_S branching ratios and CP asymmetries, which further improve the consistency between theoretical predictions and data. A predominant observation is that the ηc\eta_c mixing enhances the perturbative QCD predictions for Br(B→η′K)Br(B\to\eta'K) by 18%, but does not alter those for Br(B→ηK)Br(B\to\eta K). The puzzle due to the large Br(B→η′K)Br(B\to\eta'K) data is then resolved.Comment: 12 pages, version to appear in PR
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