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- Percival, Carl J., et al.
(författare)
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Regional and global impacts of Criegee intermediates on atmospheric sulphuric acid concentrations and first steps of aerosol formation
- 2013
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Ingår i: Faraday discussions. - : Royal Society of Chemistry (RSC). - 1359-6640 .- 1364-5498. ; 165, s. 45-73
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Tidskriftsartikel (refereegranskat)abstract
- Carbonyl oxides (Criegee intermediates), formed in the ozonolysis of alkenes, are key species in tropospheric oxidation of organic molecules and their decomposition provides a non-photolytic source of OH in the atmosphere (Johnson and Marston, Chem. Soc. Rev., 2008, 37, 699, Harrison et al., Sci. Total Environ., 2006, 360, 5, Gab et al., Nature, 1985, 316, 535, ref. 1-3). Recently it was shown that small Criegee intermediates, C.I.'s, react far more rapidly with SO2 than typically represented in tropospheric models, (Welz, Science, 2012, 335, 204, ref. 4) which suggested that carbonyl oxides could have a substantial influence on the atmospheric oxidation of SO2. Oxidation of SO2 is the main atmospheric source of sulphuric acid (H2SO4), which is a critical contributor to aerosol formation, although questions remain about the fundamental nucleation mechanism (Sipila et al., Science, 2010, 327, 1243, Metzger et al., Proc. Natl. Acad. Sci. U. S. A., 2010 107, 6646, Kirkby et al., Nature, 2011, 476, 429, ref. 5-7). Non-absorbing atmospheric aerosols, by scattering incoming solar radiation and acting as cloud condensation nuclei, have a cooling effect on climate (Intergovernmental Panel on Climate Change (IPCC), Climate Change 2007: The Physical Science Basis, Cambridge University Press, 2007, ref. 8). Here we explore the effect of the Criegees on atmospheric chemistry, and demonstrate that ozonolysis of alkenes via the reaction of Criegee intermediates potentially has a large impact on atmospheric sulphuric acid concentrations and consequently the first steps in aerosol production. Reactions of Criegee intermediates with SO2 will compete with and in places dominate over the reaction of OH with SO2 (the only other known gas-phase source of H2SO4) in many areas of the Earth's surface. In the case that the products of Criegee intermediate reactions predominantly result in H2SO4 formation, modelled particle nucleation rates can be substantially increased by the improved experimentally obtained estimates of the rate coefficients of Criegee intermediate reactions. Using both regional and global scale modelling, we show that this enhancement is likely to be highly variable spatially with local hot-spots in e. g. urban outflows. This conclusion is however contingent on a number of remaining uncertainties in Criegee intermediate chemistry.
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| 2. |
- M, Sorochinski, et al.
(författare)
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Interviewing to detect deception: When to disclose the evidence?
- 2014
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Ingår i: Journal of Police and Criminal Psychology. - : Springer Science and Business Media LLC. - 0882-0783 .- 1936-6469. ; 29:2, s. 87-94
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Tidskriftsartikel (refereegranskat)abstract
- Research shows that there are few objective cues to deception. However, it may be possible to create such cues by strategic interviewing techniques. Strategic Use of Evidence (SUE) is one such technique. The basic premise of the SUE technique is that liars and truth tellers employ different counter-interrogation strategies, and that the evidence against the suspect can be used to exploit these differences in strategies. This study examined the effect of the timing of evidence disclosure (early vs. late vs. gradual) on verbal cues to deception. We predicted that late disclosure would be most effective in differentiating between liars and truth-tellers, and that cues to deception in the gradual disclosure condition would progressively disappear due to the suspects’ realization that evidence against them exists. That is, we expected that liars in the gradual presentation condition would become more consistent with the evidence over time. A sample of 86 undergraduate students went through a mock-terrorism paradigm (half innocent, half guilty), and were subsequently interviewed using one of three disclosure strategies: early, gradual, and late disclosure. We measured statement-evidence inconsistencies as cues to deception . Results supported our predictions in that cues to deception were most pronounced in the late disclosure condition. Contrary to our expectations, the results suggested that presenting the evidence gradually may put innocent suspects at a higher risk of misclassification as they seem to adopt a strategy that is more similar to guilty suspects.
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