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| 2. |
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| 3. |
- Karlsson, Lovisa, 1989-, et al.
(författare)
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Release of metals from unprocessed and processed black shale due to natural weathering
- 2013
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Ingår i: Reliable Mine Water Technology. Volume 1. - Colorado, USA : IMWA. - 9780615793856 ; , s. 391-397
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Konferensbidrag (refereegranskat)abstract
- Black shale was mined and processed for recovery of hydrocarbons in Kvarntorp, some 200 km SW of Stockholm, Sweden, during 1942–66. Remains from the mining period is a deposit with 40 Mm³ of crushed shale residues: Unprocessed 3ne-grained shale as well as processed shale. The deposit is still hot; oxidation of sulphides as well as burning of hydrocarbons are still in progress some 50 years a1er closure. Weathering of the shale leads to releases of metal-rich leachates which will increase with time. The release of metals from pristine shale as well as weathered shale (exposed to the atmosphere for 50 years) and two di2erent processed shale residues have been studied using water of di2erent pH as leaching solution, to simulate extreme pH-variations in environmental waters: 3.0 (determined by oxidation of iron sulphides), 5.5 (bu2ered by carbon dioxide), 8.5 (bu2ered by calcite) and 12.5 (bu2ered by calcium hydroxide). Extraction of cationic elements was substantial (several percent of the total content) for Ca and Mg, as well as Ni, Co and U at pH 3, and very high (up to 50–60 %) for anionic elements (V, Mo, As) at pH 12.5. Especially the high-temperature processed shale would be a potential source for As and Mo at high pH. The pH-dependence of the weathering processes should be considered when future remediation (or metal recovery) processes and strategies are designed.
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| 4. |
- Karlsson, Stefan, 1957-, et al.
(författare)
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Water quality in a black shale mining area : effects of pH and natural organic acids on weathering and subsequent metal releases
- 2014
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Ingår i: An Interdisciplinary Response to Mine Water Challenges. - : China University of Mining and Techno logy Press. - 9787564624378 ; , s. 136-136
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Konferensbidrag (refereegranskat)abstract
- Mining of black shale (alum shale) of Late Cambrium age for the extraction of alum started in the early 17th century in Sweden, and in the late 19th century there was an extensive use of shale, with its high content of organic carbon, as fuel in lime-burning processes. Full-scale recovery of hydrocarbons from shale took place in Kvarntorp during 1942-66, and recovery of uranium in Ranstad during 1965-76. Remains from the historic mining and processing of black shale are some 50 major deposits with processed and unprocessed shale residues, as well as water-filled pits, at the former mining sites. There are also large areas covered with crushed shale, e.g. as road filling material. Studies of the weathering of shale due to exposure to the atmosphere and water with pH within the natural range indicate a high leachability of cationic elements at low pH, as well as anionic elements at high pH. The presence of organic complexing acids of natural origin (microbial exudates and humic acids) may give an enhanced leaching, particularly at pH above 8, when hydroxy-groups would constitute active metal binding sites. Results from studies of weathering and leaching of processed and unprocessed black shale are presented, as well as the effects on the water quality observed at former mining sites and related environmental impact.
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| 5. |
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| 6. |
- Ali, Sharafat, et al.
(författare)
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Effect of composition on the thermal properties and structure of M-Al-Si-O-N glasses, M = Na, Mg, Ca
- 2024
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Ingår i: Progress in Solid State Chemistry. - : Elsevier Ltd. - 0079-6786 .- 1873-1643.
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Tidskriftsartikel (refereegranskat)abstract
- The primary objective of this study is to explore the relationship between the composition, structure, and thermal characteristics of M-Al-Si-O-N glasses, with M representing sodium (Na), magnesium (Mg), or calcium (Ca). The glasses were prepared by melting in a quartz crucible at 1650 °C and AlN precursor (powder) was utilized as a nitrogen source. The measured thermal properties studied were glass transition temperature (Tg), crystallization temperature (Tc), glass stability, viscosity, and thermal expansion coefficient (α). The findings indicate that increasing the aluminum content leads to higher glass transition, crystallization temperatures, and viscosities. In contrast, fragility values increase with the Al contents, while modifier elements and silicon content influence thermal expansion coefficient values. FTIR analysis revealed that in all glasses, the dominant IR bands are attributed to the presence of Q2 and Q3 silicate units. The effect of Al is observed as a progressive polymerization of the silicate network resulting from the glass-forming role of Al2O3. In most samples, the Q4 silicate mode was also observed, strongly related to the high Al content. Overall, the study shows that the complexity of composition-property correlations where the structural changes affect the properties of Mg/Ca-based oxynitride glasses has potential implications for their use in various technological fields.
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| 7. |
- Allard, Bert, 1945-, et al.
(författare)
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Black shale : a biogeochemical archive
- 2014
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Ingår i: Sedimentary Pore Space Cementation: Role of Microbes. ; , s. 6-
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Konferensbidrag (refereegranskat)
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| 8. |
- Allard, Bert, 1945-, et al.
(författare)
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Metal Exchangeability in the REE-Enriched Biogenic Mn Oxide Birnessite from Ytterby, Sweden
- 2023
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Ingår i: Minerals. - : MDPI. - 2075-163X. ; 13:8
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Tidskriftsartikel (refereegranskat)abstract
- A black substance exuding from fractures was observed in 2012 in Ytterby mine, Sweden, and identified in 2017 as birnessite with the composition Mx[Mn(III,IV)](2)O-4 center dot(H2O)n. M is usually calcium and sodium, with x around 0.5. The Ytterby birnessite is unique, with M being calcium, magnesium, and also rare earth elements (REEs) constituting up to 2% of the total metal content. The biogenic origin of the birnessite was established in 2018. Analysis of the microbial processes leading to the birnessite formation and the REE enrichment has continued since then. The process is fast and dynamic, as indicated by the depletion of manganese and of REE and other metals in the fracture water during the passage over the precipitation zone in the mine tunnel. Studies of the exchangeability of metals in the structure are the main objective of the present program. Exposure to solutions of sodium, calcium, lanthanum, and iron led to exchanges and altered distribution of the metals in the birnessite, however, generating phases with almost identical structures after the exchanges, and no new mineral phases were detected. Exchangeability was more efficient for trivalent elements (REE) over divalent (calcium) and monovalent (sodium) elements of a similar size (ionic radii 90-100 pm).
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| 9. |
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| 11. |
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| 12. |
- Allsopp, Benjamin, et al.
(författare)
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Towards improved cover glasses for photovoltaic devices
- 2020
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Ingår i: Progress in Photovoltaics. - : John Wiley and Sons Ltd. - 1062-7995 .- 1099-159X. ; 28, s. 1187-1206
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Tidskriftsartikel (refereegranskat)abstract
- For the solar energy industry to increase its competitiveness, there is a global drive to lower the cost of solar-generated electricity. Photovoltaic (PV) module assembly is material-demanding, and the cover glass constitutes a significant proportion of the cost. Currently, 3-mm-thick glass is the predominant cover material for PV modules, accounting for 10%–25% of the total cost. Here, we review the state-of-the-art of cover glasses for PV modules and present our recent results for improvement of the glass. These improvements were demonstrated in terms of mechanical, chemical and optical properties by optimizing the glass composition, including addition of novel dopants, to produce cover glasses that can provide (i) enhanced UV protection of polymeric PV module components, potentially increasing module service lifetimes; (ii) re-emission of a proportion of the absorbed UV photon energy as visible photons capable of being absorbed by the solar cells, thereby increasing PV module efficiencies and (iii) successful laboratory-scale demonstration of proof of concept, with increases of 1%–6% in Isc and 1%–8% in Ipm. Improvements in both chemical and crack resistance of the cover glass were also achieved through modest chemical reformulation, highlighting what may be achievable within existing manufacturing technology constraints. © 2020 The Authors.
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| 13. |
- Bengtsson, F., et al.
(författare)
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Alkali ion diffusion and structure of chemically strengthened TiO2 doped soda-lime silicate glass
- 2022
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Ingår i: Journal of Non-Crystalline Solids. - : Elsevier BV. - 0022-3093 .- 1873-4812. ; 586, s. 121564-121564
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Tidskriftsartikel (refereegranskat)abstract
- Diffusion kinetics and structural properties of chemically strengthened titania-doped soda-lime silicate glasses were studied by depth-resolved X-ray photoelectron spectroscopy, Raman spectroscopy and spectrophotometry. The glasses were ion exchanged, whereby Na+ in the glass was replaced by K+ in a molten salt bath, at four different treatment temperatures between 350 and 500 °C. The alkali diffusion coefficient, DK-Na, and corresponding activation energy were calculated to be between 3.26×10−12 and 4.47×10−11 cm2s−1 and between 101.1 kJmol−1 and 105.6 kJmol−1, respectively. DK-Na was observed to decrease as the TiO2 concentration was increased. Raman analysis showed Q3-silicate species with different bond lengths, which was attributed to surface compressive stresses, and increasing Si-O-Si bond angle with increasing ion exchange temperature. Ti3+ ions exist as a minor species in the glasses and its concentration depends on the TiO2 content. Deconvolution of the optical absorption spectra reveals Jahn-Teller compressive distortion of the Ti3+ octahedral coordination.
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| 14. |
- Bengtsson, Felix, et al.
(författare)
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Dataset: Alkali Ion diffusion and structure of chemically strengthened TiO2 doped soda-lime silicate glass
- 2022
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Annan publikationabstract
- Diffusion kinetics and structural properties of chemically strengthened titania-doped soda-lime silicate glasses were studied by depth-resolved X-ray photoelectron spectroscopy, Raman spectroscopy and spectrophotometry.Chemical strengthening (CS) is frequently used to strengthen thin glasses. CS of glass is based on ion exchange of larger ions from a molten salt into glass. Both the ion and counter ion are conventionally monovalent alkali ions.Diffusion kinetics and structural properties of chemically strengthened titania-doped (TiO2) soda-lime silicate (SLS) glasses were studied by depth-resolved X-ray photoelectron spectroscopy, Raman spectroscopy and spectrophotometry. The glasses were ion exchanged, whereby Na+ in the glass was replaced by K+ in a molten salt bath, at four different treatment temperatures between 350 and 500 °C.The following samples were prepared and analyzed by X-ray Photoelectron Spectroscopy (XPS): (1) SLS, (2) 4.7% TiO2, and (3) 9.9% TiO2. The ion exchange procedure was performed for 5 h at four different temperatures below Tg (350, 400, 450 and 500 °C). Before XPS measurements, the samples were wet-etched using hydrofluoric (HF) acid to produce samples with six different etching depths.The Raman scattered light was detected in the backscattering configuration employing linear polarization and 2400 lines/mm grating, and a 100x objective lens. Depth profile spectra were collected at six different depths of 0, 10, 20, 30, 40, and 50 µm for each glass sample, employing 12 scans with a 10 s exposure time for each scan.Spectrophotometric measurements were conducted before and after K+/Na+ ion-exchange treatmeatment for 5 h at 500 °C, collected between 300 and 2500 nm.
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| 15. |
- Casillas Trujillo, Luis, et al.
(författare)
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Experimental and theoretical evidence of charge transfer in multi-component alloys : how chemical interactions reduce atomic size mismatch
- 2021
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Ingår i: Materials Chemistry Frontiers. - : Royal Society of Chemistry. - 2052-1537. ; 5:15, s. 5746-5759
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Tidskriftsartikel (refereegranskat)abstract
- Ab initio simulations of a multi-component alloy using density functional theory (DFT) were combined with experiments on thin films of the same material using X-ray photoelectron spectroscopy (XPS) to study the connection between the electronic and atomic structures of multi-component alloys. The DFT simulations were performed on an equimolar HfNbTiVZr multi-component alloy. Structure and charge transfer were evaluated using relaxed, non-relaxed, as well as elemental reference structures. The use of a fixed sphere size model allowed quantification of charge transfer, and separation into different contributions. The charge transfer was generally found to follow electronegativity trends and results in a reduced size mismatch between the elements, and thus causes a considerable reduction of the lattice distortions compared to a traditional assumption based on tabulated atomic radii. A calculation of the average deviation from the average radius (i.e. the so-called δ-parameter) based on the atomic Voronoi volumes gave a reduction of δ from ca. 6% (using the volumes in elemental reference phases) to ca. 2% (using the volumes in the relaxed multi-component alloy phase). The reliability of the theoretical results was confirmed by XPS measurements of a Hf22Nb19Ti18V19Zr21 thin film deposited by sputter deposition. The experimentally observed core level binding energy shifts (CLS), as well as peak broadening due to a range of chemical surroundings, for each element showed good agreement with the calculated DFT values. The single solid solution phase of the sample was confirmed by X-ray diffraction (XRD) and transmission electron microscopy (TEM) including energy dispersive spectroscopy (EDS) with nm-resolution. These observations show that the HfNbTiVZr solid solution phase is non-ideal, and that chemical bonding plays an important part in the structure formation, and presumably also in the properties. Our conclusions should be transferable to other multi-component alloy systems, as well as some other multi-component material systems, and open up interesting possibilities for the design of material properties via the electronic structure and controlled charge transfer between selected metallic elements in the materials.
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| 16. |
- Colleoni, Marco, et al.
(författare)
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Extended adjuvant intermittent letrozole versus continuous letrozole in postmenopausal women with breast cancer (SOLE): a multicentre, open-label, randomised, phase 3 trial.
- 2018
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Ingår i: The Lancet. Oncology. - : Elsevier. - 1474-5488 .- 1470-2045. ; 19:1, s. 127-138
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Tidskriftsartikel (refereegranskat)abstract
- In animal models of breast cancer, resistance to continuous use of letrozole can be reversed by withdrawal and reintroduction of letrozole. We therefore hypothesised that extended intermittent use of adjuvant letrozole would improve breast cancer outcome compared with continuous use of letrozole in postmenopausal women.We did the multicentre, open-label, randomised, parallel, phase 3 SOLE trial in 240 centres (academic, primary, secondary, and tertiary care centres) in 22 countries. We enrolled postmenopausal women of any age with hormone receptor-positive, lymph node-positive, and operable breast cancer for which they had undergone local treatment (surgery with or without radiotherapy) and had completed 4-6 years of adjuvant endocrine therapy. They had to be clinically free of breast cancer at enrolment and without evidence of recurrent disease at any time before randomisation. We randomly assigned women (1:1) to treatment groups of either continuous use of letrozole (2·5 mg/day orally for 5 years) or intermittent use of letrozole (2·5 mg/day orally for 9 months followed by a 3-month break in years 1-4 and then 2·5 mg/day during all 12 months of year 5). Randomisation was done by principal investigators or designee at respective centres through the internet-based system of the International Breast Cancer Study Group, was stratified by type of previous endocrine therapy (aromatase inhibitors only vs selective oestrogen receptor modulators only vs both therapies), and used permuted block sizes of four and institutional balancing. No one was masked to treatment assignment. The primary endpoint was disease-free survival, analysed by the intention-to-treat principle using a stratified log-rank test. All patients in the intention-to-treat population who initiated protocol treatment during their period of trial participation were included in the safety analyses. This study is registered with ClinicalTrials.gov, number NCT00553410, and EudraCT, number 2007-001370-88; and long-term follow-up of patients is ongoing.Between Dec 5, 2007, and Oct 8, 2012, 4884 women were enrolled and randomised after exclusion of patients at a non-adherent centre, found to have inadequate documentation of informed consent, immediately withdrew consent, or randomly assigned to intervention groups in error. 4851 women comprised the intention-to-treat population that compared extended intermittent letrozole use (n=2425) with continuous letrozole use (n=2426). After a median follow-up of 60 months (IQR 53-72), disease-free survival was 85·8% (95% CI 84·2-87·2) in the intermittent letrozole group compared with 87·5% (86·0-88·8) in the continuous letrozole group (hazard ratio 1·08, 95% CI 0·93-1·26; p=0·31). Adverse events were reported as expected and were similar between the two groups. The most common grade 3-5 adverse events were hypertension (584 [24%] of 2417 in the intermittent letrozole group vs 517 [21%] of 2411 in the continuous letrozole group) and arthralgia (136 [6%] vs 151 [6%]). 54 patients (24 [1%] in the intermittent letrozole group and 30 [1%] in the continuous letrozole group) had grade 3-5 CNS cerebrovascular ischaemia, 16 (nine [<1%] vs seven [<1%]) had grade 3-5 CNS haemorrhage, and 40 (19 [1%] vs 21 [1%]) had grade 3-5 cardiac ischaemia. In total, 23 (<1%) of 4851 patients died while on trial treatment (13 [<1%] of 2417 patients in the intermittent letrozole group vs ten [<1%] of 2411 in the continuous letrozole group).In postmenopausal women with hormone receptor-positive breast cancer, extended use of intermittent letrozole did not improve disease-free survival compared with continuous use of letrozole. An alternative schedule of extended adjuvant endocrine therapy with letrozole, including intermittent administration, might be feasible and the results of the SOLE trial support the safety of temporary treatment breaks in selected patients who might require them.Novartis and the International Breast Cancer Study Group.
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| 17. |
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| 18. |
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| 19. |
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| 20. |
- Grandin, Anna, 1973-, et al.
(författare)
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Potential use of native fungal strains for assisted uranium retention
- 2015
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Ingår i: Minerals Engineering. - : Elsevier BV. - 0892-6875 .- 1872-9444. ; 81, s. 173-178
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Tidskriftsartikel (refereegranskat)abstract
- Uranium-stabilizing ligands can be useful complexing agents for uranium in aqueous solution. The discovery of novel ligand candidates for selective uranium capture in artificial and natural waters could provide scope for their use in water remediation and metal recovery from low- and high grade ores. In this study we used seven fungal strains, isolated from shale waste, to monitor the uranium retention capacity from an aqueous solution. After four weeks of incubation, suspensions containing the fungal strains were filtered, and up to 100% of the total uranium inventory was removed from a 10 mg L-1 solution. Approximately 70% of the total uranium removal is attributed to complexation and/or adsorption by particles in the malt extract and some 10% is adsorbed by the fungal biomass. The additional 20% uranium removed could be related to the excretion of fungal metabolites. From 58% to 90% of the uranium is removed within ten minutes. The formation of colloidal/particulate uranium is proposed to be controlled by organic ligands in the culture medium and organic ligands excreted by the fungi where phosphorus moieties seem to be important. Membrane fouling by the hydrocarbons is also suggested to contribute to a loss of uranium from the aqueous phase.
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| 21. |
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| 22. |
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| 23. |
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| 26. |
- Hansson, Anna M., 1984-, et al.
(författare)
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Barriers and drivers for sustainable business model innovation based on a radical farmland change scenario
- 2023
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Ingår i: Environment, Development and Sustainability. - Dordrecht : Springer. - 1387-585X .- 1573-2975. ; 25:8, s. 8083-8106
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Tidskriftsartikel (refereegranskat)abstract
- The agricultural sector has a critical role in creating social and environmental value of natural resources in addition to its traditional role of creating economic value by supplying food to the ever-increasing world population. In fulfilling this dual role, the agricultural sector often faces competing pressures: to operate financially profitable businesses and to create, maintain, and benefit from ecosystem services (ES) in their operations. This paper analyses these pressures in an examination of drivers and barriers to the initiation of the business model innovation process for sustainability (BMIpfS) as perceived by ten agricultural business managers who operate farms in southern Sweden. The paper explores the interplay between managerial cognition and business decisions as revealed in semi-structured interviews. The new ES in focus connect to radical land-use change, paludiculture, as used in the rewetting of farmland intended to reduce the greenhouse gas emissions that drained peat soil causes. The paper contributes to the literature by identifying drivers and barriers that moderates the initiation of the BMIpfS. Although the managers acknowledge the importance of long-term, sustainable social, and environmental value creation, they have grave doubts about the profitability of activities associated with the preservation of peat soils and connected ES. These managers would benefit from taking a more proactive, long-term approach to business model changes for sustainability and from acquiring more knowledge about market demand for sustainability-oriented ES. Successful facilitation and implementation of knowledge transfer and government subsidies that support ES could improve the turning of profits based on sustainable value creation.
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| 27. |
- Johansson, Pernilla, et al.
(författare)
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Kvalitet hos byggnadsmaterial i cirkulära flöden
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Denna rapport är en del av ett projekt med det övergripande målet att bygg- och rivningsavfall i högre utsträckning skall återvinnas eller återanvändas. Detta utan att kvaliteten på materialet, och därmed framtida byggnader, försämras.Syftet med projektet har varit att kartlägga och sammanställa de kunskaper och erfarenheter som finns kring de tekniska aspekterna vid cirkulära flöden av byggmaterial, med fokus på kvalitetsfrågor, att identifiera nya projekt som kan minska mängden bygg- och rivningsavfall som deponeras eller förbränns samt att skapa nya nätverk. Det finns spridd kunskap i byggbranschen om dessa frågor och dessutom finns en mängd forskningsresultat inom olika områden. I projektet har kunskaper och erfarenheter inom området samlats in genom litteraturstudier, workshops och seminarier, studiebesök och intervjuer.I första delen av rapporten diskuteras generella tekniska erfarenheter och utmaningar i olika delar av byggkedjan, medan utmaningar för specifika materialgrupper diskuteras i den andra delen av rapporten. Dessa materialgrupper är polymera material, planglas, stenull, glasull, gipsskivor, krossad betong samt trä och träbaserade material. I rapporten redovisas en enkätundersökning som genomförts av Optimera hos deras proffskunder, i syfte att samla in dessas erfarenheter och synpunkter kring hållbart byggande.Generellt kan vi konstatera att det finns stora utmaningar med att öka återvinningsgraden för rivnings- och ombyggnadsavfall. För installationsspill och byggavfall är de tekniska utmaningarna inte lika stora. Utmaningar och förutsättningar för ökad återvinning med bibehållen god kvalitet varierar mellan olika materialslag/produkter, typ av byggprojekt samt avsedd användning.I rapporten föreslås ett antal konkreta förslag på områden där arbetet kan drivas vidare. Dessa inkluderar bland annat förbättrad/utökad inventering inför rivning och ombyggnad, rutiner och metoder för provtagning, korrekt sortering, hantering och lagring för att få rätt och jämn kvalitet, ge möjlighet för separering av sammansatta material, logistikfrågor, produktionstekniska lösningar samt kvalitetssäkring. Resultaten visar också på vikten av utbildning, nätverk och mötesplatser samt att forskningsprojekt genomförs tvärvetenskapligt. Det finns goda möjligheter för ökad återvinning genom samarbete genom hela byggkedjan.
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| 28. |
- 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. - 0002-7812 .- 1945-2705. ; 99:4, s. 26-29
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Failure of photovoltaic modules frequently occurs as a result of degradation of their encapsulation material by destructive UV radiation. Transparent TiO2 and ZnO thin films could protect against these harmful wavelengths.
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| 29. |
- Järn, Mikael, et al.
(författare)
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Mesoporous sol-gel based SiO2 thin films with ordered pore orientation as antireflective coatings on glass
- 2017
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Konferensbidrag (refereegranskat)abstract
- Antireflective coatings on glass have increasing applications, on e.g. cover glass of PV modules, display glass, spectacle lenses or window glazing’s. Sol-gel derived mesoporous coatings can be tuned both in terms of porosity and thickness, thus allowing tuning of the refractive index. Additionally, the sol-gel approach is bottom-up, which facilitates easy upscaling. In the current work we present dip-coated mesoporous silica coatings of different pore orientation and film thickness prepared on microscope glass slides and silicon wafers. The silica coatings were derived from TEOS (tetraorthosilicates) mixed with ethanol and diluted HCl. Hexagonal and cubic pore ordering of the thin films with a pore size in the range of 5-10 nm were obtained. The thin films were characterized in terms of non-contact profilometry, stylus profilometry, nanohardness, scratch resistance, UV-Vis-NIR transmittance and UV-Vis-NIR reflectance. The thicknesses of the studied films varied from 100 nm up to several hundreds of nm without jeopardizing the film homogeneity. All the mesoporous films exhibited higher transmittance than the uncoated glass substrate. The film with hexagonal pore orientation has a somewhat higher nanohardness than the cubic one, however, no difference was found in the scratch resistance for the films with different pore orientations.
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| 30. |
- Karlsson, Johan, 1984, et al.
(författare)
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Ex vivo alendronate localization at the mesoporous titania implant/bone interface
- 2015
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Ingår i: Journal of materials science. Materials in medicine. - : Springer Science and Business Media LLC. - 1573-4838 .- 0957-4530. ; 26
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Tidskriftsartikel (refereegranskat)abstract
- An attractive approach in implant technology is local drug delivery, and design of efficient, safe and reliable treatments. Ourhitherto strategy has been to coat Ti implants with a thin mesoporous TiO2 film that in turnis loaded with an osteoporosis drug, such as Alendronate (ALN) that is known to suppress osteoclastic activity. This system has proven highly successful and results in excellent osseointegration. However, more detailed information about drug-release and distribution at the bone/implant interface is needed. In this study, (14)C-ALN loaded titanium implants were placed up to 8weeks into rat tibia and the spatial-temporal distribution of the drug was evaluated. Autoradiography data demonstrated a sustained release of (14)C-ALN and the releaseddrug remained bound to bone in close vicinity, within 500 micrometers,of the implants. Liquid scintillation counting experiments confirmed that the distal transport of released (14)C-ALN was extremely low. The results are favorable as they show that ALN stays for a long time in the vicinity of the implant and may therefore improve for a long time the mechanical fixation of bone anchored implants. Moreover, these findings suggest due to the low systemic spreading a minimal risk of Alendronate related systemic side effects.
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| 31. |
- Karlsson, Stefan, 1957-, et al.
(författare)
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Analysis of Acid Rock Drainage (ARD) with Micro Plasma Atomic Emission Spectroscopy (MP AES) – Comparison with ICP-MS
- 2014
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Ingår i: Annual International Mine Water Association Conference. - Xuzhou : China University of Mining and Technology Press. - 9787564624378 ; , s. 131-135
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Konferensbidrag (refereegranskat)abstract
- Analysis of dissolved metals in acid rock drainage (ARD) with an Agilent 4100 MP AES instrument that combines a nitrogen micro plasma with atomic emission detection (MP AES) was compared with an ICP-MS. Sample preparation consisted only of filtration, acidification (HNO3 1%) and addition of internal standard elements after appropriate dilution. In these complex matrices the systems gave identical results provided that care was taken to avoid ionization. This was easily done by addition of CsNO3 which eliminated the need for matrix matching of calibration solutions. The use of internal standards is only needed for elements with known spectral interferences.
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| 32. |
- Karlsson, Stefan, 1984-, et al.
(författare)
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Antireflektiv beläggning i världsklass ger effektivare solfångare
- 2023
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Ingår i: GLAS. ; :4, s. 36-37
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- I ett nyligen avslutat forskningsprojekt har Absolicon Solar Collector tillsammans med RISE Research Institutes of Sweden och Umeå universitet utvecklat en ny toppmodern antireflektiv beläggning som kan göra Absolicons solfångare än mer effektiva. Nu siktar man på ett nytt projekt för att skala upp metoden.
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| 33. |
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| 34. |
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| 35. |
- Karlsson, Stefan, 1984-, et al.
(författare)
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Chemical strengthening of flat glass by vapour deposition and in-line alkali metal ion exchange
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Glass is a common material in the everyday life. It is widely used in a variety ofapplications e.g. architectural, automotive, containers, drinking vessels, displays,insulation and optical fibers due to its universal forming ability, transparency, chemicaldurability, form stability, hardness and relatively low price. Flat glass is a wide market ofthe glass industry and generally ninety percent of all flat glass produced worldwide ismanufactured using the float forming process. There is a large market strive for thinnerand stronger glass in order to reduce costs, save energy, reduce environmental footprint,find new applications and to improve the working environment for labour working withmounting flat glass.This study comprises the modification of flat/float glass surface by a novel route;exchange of ionic species originating from in-line vapour deposition of salt compared tothe conventional route of immersing the glass in molten salt baths. The aim of this workis to develop a novel process in order to improve the mechanical strength of flat/floatglass by introducing external material to the surface in a process with the obviouspotential to be automatic in industrial processes. Chemical strengthening has beenperformed by applying potassium chloride to the glass surface by vapour deposition andthermally activated ion exchange. The method presented here is anticipated to be used inproduction in the future and would make it possible to produce larger quantities ofchemically strengthened flat glass to a considerably lower cost.
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| 36. |
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| 37. |
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| 38. |
- Karlsson, Stefan, 1957-, et al.
(författare)
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Comparison of MP AES and ICP-MS for analysis of principal and selected trace elements in nitric acid digests of sunflower (Helianthus annuus)
- 2015
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Ingår i: Talanta. - : Elsevier BV. - 0039-9140 .- 1873-3573. ; 135, s. 124-132
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Tidskriftsartikel (refereegranskat)abstract
- The use of nitrogen as plasma gas for microwave plasma atomic emission spectroscopy (MP AES) is an interesting development in analytical science since the running cost can be significantly reduced in comparison to the inductively coupled argon plasma. Here, we evaluate the performance of the Agilent 4100 MP AES instrument for the analysis of principal metals (Ca, K, Mg, and Na), lithogenic metals (Al, Fe, and Mn) and selected trace metals (As, Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, V, and Zn) in nitric acid plant digests. The digests were prepared by microwave-assisted dissolution of dry plant material from sunflower (Helianthus annuus) in concentrated nitric acid. Comparisons are made with analysis of the same solutions with ICP-MS (Agilent 7500cx) using the octopole reaction system (ORS) in the collision mode for As, Fe, and V.The limits of detection were usually in the low μg L-1 range and all principal and lithogenic metals were successfully determined with the MP AES and provided almost identical results with the ICP-MS. The same applies for the selected trace metals except for As, Co and Mo where the concentrations were below the detection limit with the MP AES. For successful analysis we recommend that (i) only atom lines are used, (ii) ionization is minimized (e.g. addition of CsNO3) and (iii) the use of internal standards should be considered to resolve spectral interferences.
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| 39. |
- Karlsson, Stefan, 1984-
(författare)
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Compositional Effects on Indentation Mechanical Properties of Chemically Strengthened TiO2-Doped Soda Lime Silicate Glasses
- 2022
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Ingår i: Materials. - Basel, Switzerland : MDPI. - 1996-1944. ; 15:2
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Tidskriftsartikel (refereegranskat)abstract
- TiO2 is an important oxide for property modifications in the conventional soda lime silicate glass family. It offers interesting optical and mechanical properties, for instance, by substituting heavy metals such as lead in consumer glasses. The compositional effects on the hardness, reduced elastic modulus and crack resistance as determined by indentation of chemically strengthened (CS) TiO2-doped soda lime silicate glass was studied in the current paper. The CS, which was performed by a K+ for Na+ ion exchange in a molten KNO3 salt bath at 450 °C for 15 h, yielded significant changes in the indentation mechanical properties. The hardness of the glass samples increased, and this was notably dependent on the SiO2, CaO and TiO2 content. The reduced elastic modulus was less affected by the CS but showed decrease for most samples. The crack resistance, an important property in many applications where glasses are subjected to contact damage, showed very different behaviors among the series. Only one of the series did significantly improve the crack resistance where low CaO content, high TiO2 content, high molar volume and increased elastic deformation favored an increased crack resistance.
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| 40. |
- Karlsson, Stefan, 1957-, et al.
(författare)
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Concentration dynamics in a boreal catchment : trace elements, REEs and humic substances
- 2011
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Ingår i: 25th International Applied Geochemistry Symposium, 22-26 August, 2011, Rovaniemi, Finland. - Rovaniemi, Finland : Vuorimiesyhdistys - Finnish Association of Mining and Metallurgical Engineers. - 9789529618637 ; , s. 63-63
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Konferensbidrag (refereegranskat)
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| 41. |
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| 42. |
- Karlsson, Stefan, 1984-, et al.
(författare)
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Copper, silver, rubidium and caesium ion exchange in soda-lime-silicate float glass by direct deposition and in line melting of salt pastes
- 2012
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Ingår i: European Journal of Glass Science and Technology. Part A: Glass Technology. - 1753-3546. ; 53:1, s. 1-7
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Tidskriftsartikel (refereegranskat)abstract
- We report the change of surface composition on commercial soda-lime-silica (SLS) float glass which results from single-side exchange of Na+ by Cu+, Ag+, Rb+ and Cs+, respectively. Ion exchange is achieved by in line melting of a directly deposited salt paste in a prolonged annealing procedure. Concentration profiles obtained and computed effective diffusion coefficients, as well as apparent activation energies for diffusion, are reported. Depending on exchange species, treatment time and treatment temperature, the penetration depths are in the range of 10-20 μm for K+, Cu+, Rb+ and Cs+. A penetration depth of >100 μm can readily be obtained for Ag+.
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| 43. |
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| 44. |
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| 45. |
- Karlsson, Stefan, 1984-, et al.
(författare)
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Dataset: Mechanical, thermal, and structural investigations of chemically strengthened Na2O–CaO–Al2O3–SiO2 glasses
- 2022
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Annan publikationabstract
- We investigated the effect of alumina doping on thermal, mechanical, and structural properties of a conventional soda lime silicate glass before and after ion exchange strengthening. The techniques to measure properties were:- 23Na and 27Al Magic Angle Spinning Nuclear Magnetic Resonance (MAS NMR)- Scattered light polariscope- Differential Thermal Analysis (DTA)- Nanoindentation- MicroindentationMore detailed information can be found in the documentation-readme file.
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| 46. |
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| 47. |
- Karlsson, Stefan, 1984-
(författare)
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Dataset: Viscosity of alumina doped soda lime silicate glasses
- 2021
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Annan publikationabstract
- Adding alumina to the conventional soda lime silicate glass composition improves many properties, however, also increases the viscosity. Alumina doping of soda lime silicate glasses is investigated and its implications to high temperature viscosity as SiO2 is replaced by Al2O3.
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| 48. |
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| 49. |
- Karlsson, Stefan, 1984
(författare)
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Development of novel vaccine strains of Vibrio cholerae and studies on the role of serotype in epidemic spread of cholera
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Cholera, caused by bacterium Vibrio cholerae O1, is a severe diarrheal disease with an estimated 3-5 million cases and more than 140 000 deaths every year particularly affecting children under 5 years of age. It can be found all over the world and often causes cholera in places where access to clean water or proper sanitary facilities are limited or compromised. Typically cholera follows in the wake of natural disasters or man-made catastrophes but it is also endemic in many countries including India and Bangladesh. Today there are two licensed vaccines available on the market in more than 60 countries. Despite the fact that these vaccines are effective they are both expensive and complicated to manufacture and there is scope and motivation for creating a new cheaper and more effective vaccine against cholera. First, we have shown that it is possible by genetic manipulation to generate a single strain vaccine expressing two phenotypically different phenotypes and shown that the candidate vaccine strains elicit similar immune responses as the current licensed vaccine Dukoral. This is a huge benefit since it will significantly simplify manufacture and reduce production costs. Further, we have investigated the naturally occurring Inaba serotype mutants and generated a hypothesis as to why O1 serogroup Vibrio cholerae maintains a serotype polymorphism. We have conducted a unique study where we could show that selective pressure on the circulating strains in the environment is almost certainly what is driving serotype transition. Taken together, results from this thesis show how the use of bioinformatics can be used to target genes and even specific amino acids for mutagenesis in order to modify the phenotype of a vaccine strain and understand the unique and fundamental role of serotype with respect to epidemic and endemic cholera.
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| 50. |
- Karlsson, Stefan, 1984-, et al.
(författare)
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Diffusion and ion exchange of float glass : Na+ substitution by Cu+, Ag+, Rb+ and Cs
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In this paper, single-side ion exchange on commercial float glass of the monovalent cations Cu+, Ag+, Rb+ and Cs+ is described. Data on the concentration profiles and calculations on thediffusion coefficients as well as activation energies are reported. The ion exchange of sodiumfor copper or silver is complex, since it is affected by the distribution of the element indifferent oxidation states. Anyhow, it was possible to determine the Cu+ diffusion coefficientsto be in the range 8.0E-12 to 3.4E-11 cm2s-1 and the activation energy 115 kJ/mol. Thepenetration depth of Cu+ exceeds 25 μm. The average diffusion coefficients of silver werecalculated to be in the range 2.1E-10 to 9.9E-10 cm2s-1 and the activation energies for samplestreated at temperatures higher than 470 ºC to 152 kJ/mol and 185 kJ/mol for air-side and tinsiderespectively. The Ag+ penetration depth is beyond 150 μm for the highest temperatures.Rb+-Na+ ion exchange reaches a penetration depth of approximately 10 μm with diffusioncoefficients ranging from 1.7E-12 to 8.6E-13 cm2s-1 while Cs+-Na+ ion exchange reaches apenetration depth of approximately 7 μm with diffusion coefficients ranging from 6.2E-13 to3.8E-13 cm2s-1.
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