| 82511. |
- Kristiansson, Moa K., 1989-, et al.
(författare)
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High-precision electron affinity of oxygen
- 2022
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Negative ions are important in many areas of science and technology, e.g., in interstellar chemistry, for accelerator-based radionuclide dating, and in anti-matter research. They are unique quantum systems where electron-correlation effects govern their properties. Atomic anions are loosely bound systems, which with very few exceptions lack optically allowed transitions. This limits prospects for high-resolution spectroscopy, and related negative-ion detection methods. Here, we present a method to measure negative ion binding energies with an order of magnitude higher precision than what has been possible before. By laser-manipulation of quantum-state populations, we are able to strongly reduce the background from photodetachment of excited states using a cryogenic electrostatic ion-beam storage ring where keV ion beams can circulate for up to hours. The method is applicable to negative ions in general and here we report an electron affinity of 1.461 112 972(87) eV for O-16. High-precision measurements are useful to find isotopic shifts and electron correlation. Here the authors measure electron affinity and hyperfine splitting of atomic oxygen with higher precision than previous studies.
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| 82512. |
- Kristiansson, Moa K., et al.
(författare)
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Measurement of the lifetime of a metastable excited state in Bi
- 2022
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Ingår i: Physical Review A. - 2469-9926 .- 2469-9934. ; 105:1
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Tidskriftsartikel (refereegranskat)abstract
- The lifetime of the P03 state of Bi- has been measured by selective photodetachment in a cryogenic ion-beam storage ring. By measuring the lifetime as a function of applied laser powers and extrapolating to zero laser power, a lifetime of 16.0±0.5 s is deduced for electric quadrupole decay of the excited state to the ground sate. The result provides a stringent test of recent state-of-the art theoretical calculations. © 2022 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by "https://www.kb.se/samverkan-och-utveckling/oppen-tillgang-och-bibsamkonsortiet/bibsamkonsortiet.html"Bibsam.
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| 82513. |
- Kristiansson, M. K., et al.
(författare)
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Photodetachment Studies of Ir- Ions at DESIREE
- 2020
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Ingår i: Journal of Physics: Conference Series, Volume 1412, Structure / Spectroscopy. - : IOP. - 1742-6588.
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Konferensbidrag (refereegranskat)abstract
- Anions of iridium were stored in the cryogenic storage ring, DESIREE [1, 2, 3] and investigated using laser photodetachment. The ions were stored for up to 2000 seconds and the relaxation of several metastable states were studied by selecting different photon energies. The threshold of the previously not observed P-3(2) level is located and the lifetime of this sate is found to be longer than the storage time of the ion beam. We also find that a state exists higher in energy than the previously known level with a lifetime in the range of hundreds of milliseconds.
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| 82514. |
- Kristiansson, Marianne, et al.
(författare)
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Sekretess hinder för hantering av högriskindivider.
- 2014
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Ingår i: Svenska Dagbladet. - 1101-2412. ; :21 nov 2014
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- För att olika myndigheter ska kunna samverka när det gäller personer med psykisk sjukdom som riskerar att begå brott, krävs att nuvarande sekretessbestämmelser förändras.
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| 82515. |
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| 82516. |
- Kristiansson, Marianne, et al.
(författare)
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"Sjuk eller frisk" i rättspsykiatrisk mening. Vad säger lagen?
- 2014
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Ingår i: MAD, SAD or BAD? Nedslag i svensk rättspsykiatrisk forskning - en festskrift till Anders Forsmans 70-årsdag. Henrik Anckarsäter, Thomas Nilsson, Susanna Radovic (red.). - : Göteborgs universitet. Institutionen för filosofi, lingvistik och vetenskapsteori. - 1652-0459. - 9789163754357 ; , s. 75-80
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Denna översiktsartikel presenterar det svenska rättspsykiatriska systemet i förhållande till lagstiftningen och förslag till förändringar i den. Kapitlet har tidigare varit publicerat i Läkartidningen och författarna var vid tiden för den ursprungliga publikationen verksamhetschefer för de två stora statliga utredningsenheterna i Sverige, i Stockholm och Göteborg.
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| 82517. |
- Kristiansson, Martin, et al.
(författare)
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Undervisning om migration på vetenskaplig grund. Lärares kunskapsbildning inom SO på svenskt mellanstadium : Teaching about migration on a scientific base: Teachers’ knowledge-building in social studies in Swedish upper elementary school
- 2023
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Ingår i: Acta Didactica Norden. - 2535-8219. ; 17:3
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Tidskriftsartikel (refereegranskat)abstract
- This article examines two conversations in a study-circle on migration. The conversations are part of the first phase of a subject didactic project between social studies teachers at upper elementary school and researchers at a university in Sweden. In the conversations, which are moderated by two researchers, the teachers are expected to build their own knowledge about migration and how teaching about migration can be carried out. Previous research on social studies teaching in the earlier school years has shown that the connection to substantive scientific knowledge is weak. Through deeper theoretical knowledge and an increased didactic repertoire, teachers can in turn give students access to specialised knowledge, i.e. knowledge that helps them deal with society's major issues. The article aims to investigate how the teachers' knowledge building can be made visible and understood, as well as what function the researchers fulfill in the conversations. Both conversations have been analyzed semantically with tools from Legitimation Code Theory. Through the analysis, we follow how scientific substantive knowledge about migration is transformed and linked to teachers' experiences and more general everyday understanding of the phenomenon. The analysis shows that there is a connection between an everyday understanding and a scientific understanding in the part of the conversation where the teachers build their own knowledge about migration, but that it is more difficult to achieve a connection between scientific knowledge and developing the teaching content. Here, a focus on the content, on what should be taught and why, seems to make it easier for teachers to make connections to specialized knowledge, while a focus on how-to questions and who should be taught does not do so to the same extent.
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| 82518. |
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| 82519. |
- Kristin, Haynert, et al.
(författare)
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Biometry and dissolution features of the benthic foraminifer Ammonia aomoriensis at high pCO2 : Ammonia aomoriensis at high pCO2
- 2011
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Ingår i: MARINE ECOLOGY PROGRESS SERIES. - : Inter-Research Science Center. - 0171-8630 .- 1616-1599. ; 432, s. 53-67
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Tidskriftsartikel (refereegranskat)abstract
- Culturing experiments were performed with the benthic foraminifer Ammonia aomo- riensis from Flensburg Fjord, western Baltic Sea. The experiments simulated a projected rise in atmospheric CO2 concentrations. We exposed specimens to 5 seawater pCO2 levels ranging from 618 μatm (pH 7.9) to 3130 μatm (pH 7.2) for 6 wk. Growth rates and mortality differed significantly among pCO2 treatments. The highest increase of mean test diameter (19%) was observed at 618 μatm. At partial pressures >1829 μatm, the mean test diameter was observed to decrease, by up to 22% at 3130 μatm. At pCO2 levels of 618 and 751 μatm, A. aomoriensis tests were found intact after the experiment. The outer chambers of specimens incubated at 929 and 1829 μatm were severely damaged by corrosion. Visual inspection of specimens incubated at 3130 μatm revealed wall dissolu- tion of all outer chambers, only their inner organic lining stayed intact. Our results demonstrate that pCO2 values of ≥929 μatm in Baltic Sea waters cause reduced growth of A. aomoriensis and lead to shell dissolution. The bottom waters in Flensburg Fjord and adjacent areas regularly experience pCO2 levels in this range during summer and fall. Increasing atmospheric CO2 concentrations are likely to extend and intensify these periods of undersaturation. This may eventually slow down calci- fication in A. aomoriensis to the extent that net carbonate precipitation terminates. The possible dis- appearance of this species from the Baltic Sea and other areas prone to seasonal undersaturation would likely cause significant shifts in shallow-water benthic ecosystems in the near future.
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| 82520. |
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