Secondary Ice Production : Current State of the Science and Recommendations for the Future

Measured ice crystal concentrations in natural clouds at modest supercooling (temperature ~>-10°C) are often orders of magnitude greater than the number concentration of primary ice nucleating particles. Therefore, it has long been proposed that a secondary ice production process must exist that is able to rapidly enhance the number concentration of the ice population following initial primary ice nucleation events. Secondary ice production is important for the prediction of ice crystal concentration and the subsequent evolution of some types of clouds, but the physical basis of the process is not understood and the production rates are not well constrained. In November 2015 an international workshop was held to discuss the current state of the science and future work to constrain and improve our understanding of secondary ice production processes. Examples and recommendations for in situ observations, remote sensing, laboratory investigations, and modeling approaches are presented.Peer reviewe

Exploring diversity in the relationships between teacher quality and job satisfaction in the Nordic countries : insights from TALIS 2013 and 2018

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Probing Isotope Shifts in 103Rh and 195Pt NMR Spectra with Density Functional Theory

Zero-point vibrationally averaged (rg0) structures were computed at the PBE0/SDD/6-31G* level for the [Pt35Cln37Cl5–n(H218O)]− (n = 0–5), cis-Pt35Cln37Cl4–n(H218O)(H216O) (n = 0–4), fac-[Pt35Cln37Cl3–n(H218O)(H216O)2]+ (n = 0–3), [Pt35Cln37Cl5–n(16/18OH)]2– (n = 0–5), cis-[Pt35Cln37Cl4–n(16/18OH)2]2– (n = 0–4), fac-[Pt35Cln37Cl3–n(16/18OH)3]2– (n = 0–3), cis-[Pt35Cln37Cl2–n(16/18OH)4]2– (n = 0–2), [Pt35Cln37Cl1–n(16/18OH)5]2– (n = 0–1), [Rh35Cln37Cl5–n(H2O)]2– (n = 0–5), cis-[Rh35Cln37Cl4–n(H2O)2]− (n = 0–4), and fac-Rh35Cln37Cl3–n(H2O)3 (n = 0–3) isotopologues and isotopomers. Magnetic shielding constants, computed at the ZORA-SO/PW91/QZ4P/TZ2P level, were used to evaluate the corresponding 35/37Cl isotope shifts on the 195Pt and 103Rh NMR spectra, which are known experimentally. While the observed effects are reproduced reasonably well computationally in terms of qualitative trends and the overall order of magnitude (ca. 1 ppm), quantitative agreement with experiment is not yet achieved. Only small changes in M–Cl and M–O bonds upon isotopic substitution, on the order of femtometers, are necessary to produce the observed isotope shifts.PostprintPeer reviewe

On the Origin of Cl-35/37 Isotope Effects on Pt-195 NMR Chemical Shifts. A Density Functional Study

Zero-point vibrationally averaged (r(g)(0)) structures were computed at the PBE0/SDD/6-31G* level for [(PtCl6)-Cl-35](2-) and [(PtCl6)-Cl-37](2-), for the [(Pt35ClnCl5-n)-Cl-37(H2O)](-) (n = 0-5), cis-(PtClnCl(4-n))-Cl-35-Cl-37(H2O)(2) (n = 0-4), and fac-[(PtClnCl(3-n))-Cl-35-Cl-37(H2O)(3)](+) (n = 0-3) isotopologues and isotopomers. Magnetic Pt-195 shielding constants, computed at the ZORA-SO/PW91/QZ4P/TZ2P level, were used to evaluate the corresponding Cl-35/37 isotope shifts in the experimental Pt-195 NMR spectra. While the observed effects are reproduced reasonably well computationally in terms of qualitative trends and the overall order of magnitude (ca. 1 ppm), quantitative agreement with experiment is not yet achieved. Only small changes in Pt-Cl and Pt-O bond lengths upon isotopic substitution, on the order of femtometers, are necessary to produce the observed isotope shifts.</p

On the Origin of Cl-35/37 Isotope Effects on Pt-195 NMR Chemical Shifts. A Density Functional Study

Zero-point vibrationally averaged (r(g)(0)) structures were computed at the PBE0/SDD/6-31G* level for [(PtCl6)-Cl-35](2-) and [(PtCl6)-Cl-37](2-), for the [(Pt35ClnCl5-n)-Cl-37(H2O)](-) (n = 0-5), cis-(PtClnCl(4-n))-Cl-35-Cl-37(H2O)(2) (n = 0-4), and fac-[(PtClnCl(3-n))-Cl-35-Cl-37(H2O)(3)](+) (n = 0-3) isotopologues and isotopomers. Magnetic Pt-195 shielding constants, computed at the ZORA-SO/PW91/QZ4P/TZ2P level, were used to evaluate the corresponding Cl-35/37 isotope shifts in the experimental Pt-195 NMR spectra. While the observed effects are reproduced reasonably well computationally in terms of qualitative trends and the overall order of magnitude (ca. 1 ppm), quantitative agreement with experiment is not yet achieved. Only small changes in Pt-Cl and Pt-O bond lengths upon isotopic substitution, on the order of femtometers, are necessary to produce the observed isotope shifts.</p

Probing Isotope Shifts in ¹⁰³Rh and ¹⁹⁵Pt NMR Spectra with Density Functional Theory

Zero-point vibrationally averaged (rg0) structures were computed at the PBE0/SDD/6-31G* level for the [Pt35Cln37Cl5–n(H218O)]− (n = 0–5), cis-Pt35Cln37Cl4–n(H218O)(H216O) (n = 0–4), fac-[Pt35Cln37Cl3–n(H218O)(H216O)2]+ (n = 0–3), [Pt35Cln37Cl5–n(16/18OH)]2– (n = 0–5), cis-[Pt35Cln37Cl4–n(16/18OH)2]2– (n = 0–4), fac-[Pt35Cln37Cl3–n(16/18OH)3]2– (n = 0–3), cis-[Pt35Cln37Cl2–n(16/18OH)4]2– (n = 0–2), [Pt35Cln37Cl1–n(16/18OH)5]2– (n = 0–1), [Rh35Cln37Cl5–n(H2O)]2– (n = 0–5), cis-[Rh35Cln37Cl4–n(H2O)2]− (n = 0–4), and fac-Rh35Cln37Cl3–n(H2O)3 (n = 0–3) isotopologues and isotopomers. Magnetic shielding constants, computed at the ZORA-SO/PW91/QZ4P/TZ2P level, were used to evaluate the corresponding 35/37Cl isotope shifts on the 195Pt and 103Rh NMR spectra, which are known experimentally. While the observed effects are reproduced reasonably well computationally in terms of qualitative trends and the overall order of magnitude (ca. 1 ppm), quantitative agreement with experiment is not yet achieved. Only small changes in M–Cl and M–O bonds upon isotopic substitution, on the order of femtometers, are necessary to produce the observed isotope shifts. </p

Pebble stoves for heating gases to high temperatures /

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Control of sulfur content of sponge iron produced in rotary kilns /

"March 1947."Mode of access: Internet