| 1. |
- Rodríguez-Varela, Ricardo, et al.
(författare)
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The genetic history of Scandinavia from the Roman Iron Age to the present
- 2023
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Ingår i: Cell. - : Elsevier. - 0092-8674 .- 1097-4172. ; 186:1, s. 32-46
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Tidskriftsartikel (refereegranskat)abstract
- We investigate a 2,000-year genetic transect through Scandinavia spanning the Iron Age to the present, based on 48 new and 249 published ancient genomes and genotypes from 16,638 modern individuals. We find regional variation in the timing and magnitude of gene flow from three sources: the eastern Baltic, the British-Irish Isles, and southern Europe. British-Irish ancestry was widespread in Scandinavia from the Viking period, whereas eastern Baltic ancestry is more localized to Gotland and central Sweden. In some regions, a drop in current levels of external ancestry suggests that ancient immigrants contributed proportionately less to the modern Scandinavian gene pool than indicated by the ancestry of genomes from the Viking and Medieval periods. Finally, we show that a north-south genetic cline that characterizes modern Scandinavians is mainly due to the differential levels of Uralic ancestry and that this cline existed in the Viking Age and possibly earlier.
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| 2. |
- Bring, Torun, et al.
(författare)
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Colour development in copper ruby alkali silicate glasses. : Part 2. The effect of tin (II) oxide and antimony (III) oxide
- 2007
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Ingår i: GLASS TECHNOLOGY-EUROPEAN JOURNAL OF GLASS SCIENCE AND TECHNOLOGY PART A. - : Society of Glass Technology. - 1753-3546. ; 48:3, s. 142-148
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Tidskriftsartikel (refereegranskat)abstract
- The effect of Sb3+ and Sn2+ during the heat treatment of copper ruby alkali silicate glasses is investigated. The reducing power of SnO and Sb2O3 with respect to Cu is investigated and it is concluded that SnO has the strongest reducing capability. When Cu2O and SnO concentrations are low, minor additions of Sb2O3 have an observable impact on colour development and absorbance, as thin pieces of glass develop a bluish tint and a larger shift towards longer wavelengths is observed in UV/vis spectra. The differences in colour and spectra are suggested to be caused by differences in size of the colour forming agent, Cu metal particles.
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| 3. |
- Bring, Torun, et al.
(författare)
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Colour development in copper ruby alkali silicate glasses : Part 1. The impact of tin (II) oxide, time and temperature
- 2007
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Ingår i: Glass Technology, Eur J Glass Sci Technol A. - : Society of Glass Technology. ; 48:2, s. 101-108
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Tidskriftsartikel (refereegranskat)abstract
- The development of the red colour in copper ruby alkali silicate glasses has been studied by means of ultraviolet/visible spectroscopy, TEM and EXAFS. The results show that in both red and slightly overstruck, brownish glasses the colour is due to clusters of metallic copper. Before striking non-coloured glasses contain mainly cuprous ions, Cu+. Tin acts as a reducing agent but also has an accelerating effect on colour development.
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| 4. |
- Bring, Torun, et al.
(författare)
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Potassium sulfate droplets and the origin of turbidity in alabaster glass
- 2006
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Ingår i: Glass Technology : European Journal of Glass Science and Technology A. ; 47:1, s. 15-18
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Tidskriftsartikel (refereegranskat)abstract
- A study of the criteria required to manufacture multi-component semi-transparent silicate glasses, so called “alabaster” glass, has found that the optical effect is caused by non-crystal¬line potassium sulfate droplets. The droplets were characterized by use of XRD, SEM/EDX and Raman spectroscopy. The size range of the particles is in the order of 5-50 micrometers. It was found that the droplets consisted of potassium sulfate, even if other sulfate compounds were added to the glass. The amount of sulfate compound added, the melting temperature of the furnace and the melting time have significant effect on the optical density of the glass. The optical density of the glass can be correlated to the calculated surface tension of the host glass, suggesting that phase separation of a sulfate enriched liquid phase is part of the mecha¬nism forming the droplets. By adding pigments several different colours can be obtained, but the alabaster effect is not achieved during reducing conditions, thus it seems not possible to produce colours originating from reduced pigments. Pigments tested were Cr, Fe, Co, Cu, Au, Mo/Se, Nd and Ti/Ce/Se.
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| 5. |
- Bring, Torun, et al.
(författare)
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Selenium : molybdenum-based coloration of alkali silicate glasses
- 2007
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Ingår i: Glass Technology. - : Society of Glass Technology. - 0017-1050. ; 48:5, s. 213-221
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Tidskriftsartikel (refereegranskat)abstract
- The interaction between selenium and molybdenum in reduced alkali silicate melts, resulting in red glasses has been studied. The oxidation state of Mo is Mo(VI) as evidenced by XANES and ESCA results. Selenium is present in a reduced state, as indicated by ultraviolet/visible spectroscopy and XANES. The colour is described by ultraviolet/visible spectra and CIE colour coordinates. The main absorption peaks are at 450 and 540 nm. Similar bands are reported for MoOSe32−. Several commonly used glass components must be avoided in the batch, as they prevent formation of the red colour.
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| 6. |
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| 7. |
- Johansson, Wilhelm, et al.
(författare)
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Transparent TiO2 and ZnO Thin Films on Glass for UV Protection of PV Modules
- 2020
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Ingår i: American Ceramic Society Bulletin. - : American Ceramic Society Inc.. - 0002-7812 .- 1945-2705. ; 99:4, s. 26-29
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- To stabilize the global temperature and mitigate climate change, the emission of anthropogenic greenhouse gases will have to be greatly reduced. To make it possible, the energy sector will have to transfer from fossil energy to environmentally friendly and carbon neutral sources.
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| 8. |
- Johansson, Wilhelm, et al.
(författare)
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Transparent TiO2 and ZnO Thin Films on Glass for UV Protection of PV Modules
- 2019
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Ingår i: Frontiers in Materials. - Lausanne, Switzerland : Frontiers Media S.A.. - 2296-8016. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Failure of PV modules frequently occurs as a result of degradation of their encapsulation material by destructive UV radiation. Both the life expectancy and efficiency of PV modules can be improved by reducing the transmittance of the destructive UV radiation through the cover glass without compromising the transmittance in the visible wavelength region. In addition, if the absorbed UV photons can be down-shifted to wavelengths that can be more efficiently converted to electrical energy, an additional increase of the PV efficiency could be achieved. In this study we have investigated transparent ZnO and TiO2 thin films deposited by spray pyrolysis on soda lime silicate float glass as functional layers on PV cover glass. The optical bandgap, UV-cutoff, UV-Vis transmittance, reflectivity (total and diffuse) and photoluminescence have been determined. The ZnO coating shifted the optical bandgap to longer wavelengths, resulting in a reduction of the transmittance of destructive UV radiation by up to ∼85%. Distinct photoluminescence peaks at 377 nm and at 640 nm were observed for one of the ZnO samples. The TiO2 coated glasses also showed an increased UV cutoff, which resulted in a reduction of transmittance of destructive UV radiation by up to 75%. However, no photoluminescence peaks could be observed from the TiO2 films with 325 nm excitation laser, which can be explained by the fact that only indirect interband transitions are accessible at this excitation wavelength. Deposition of both ZnO and TiO2 coatings resulted in a reduction of the transmitted light convertible by PV modules, by up to 12.3 and 21.8%, respectively. The implication of the results is discussed in terms of lifetime expectancy and efficiency of PV modules.
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