| 1. |
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| 2. |
- Sundberg, Klas, et al.
(author)
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Modern project management : Challenges for the future
- 2021
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In: Management and Information Technology after Digital Transformation. - London : Routledge. - 9781003111245 - 9780367612764 ; , s. 93-104
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Book chapter (peer-reviewed)abstract
- In this chapter, the authors highlight that the challenges related to managing modern projects are that the management problems have changed since traditional project management methods were developed. This calls for new project management methods, adapted to situations of rapid technological change and flexibility. The authors identify and highlight the limitations of both traditional and agile management methods. They pay special attention to such project characteristics as obstacles to agility, skills, leadership, stakeholders and customers. They discuss hybrid project management and identify which method is the best fit in a given situation.
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| 3. |
- Takahashi Schmidt, Junko, et al.
(author)
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KORRIGAN1 and its Aspen Homolog PttCel9A1 Decrease Cellulose Crystallinity in Arabidopsis Stems
- 2009
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In: Plant and Cell Physiology. - : Oxford University Press (OUP). - 0032-0781 .- 1471-9053. ; 50:6, s. 1099-1115
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Journal article (peer-reviewed)abstract
- KORRIGAN1 (KOR1) is a membrane-bound cellulase implicated in cellulose biosynthesis. PttCel9A1 from hybrid aspen (Populus tremula L. tremuloides Michx.) has high sequence similarity to KOR1 and we demonstrate here that it complements kor1-1 mutants, indicating that it is a KOR1 ortholog. We investigated the function of PttCel9A1/KOR1 in Arabidopsis secondary growth using transgenic lines expressing 35S::PttCel9A1 and the KOR1 mutant line irx2-2. The presence of elevated levels of PttCel9A1/KOR1 in secondary walls of 35S::PttCel9A1 lines was confirmed by in muro visualization of cellulase activity. Compared with the wild type, 35S::PttCel9A1 lines had higher trifluoroacetic acid (TFA)-hydrolyzable glucan contents, similar Updegraff cellulose contents and lower cellulose crystallinity indices, as determined by C-13 solid-state nuclear magnetic resonance (NMR) spectroscopy. irx2-2 mutants had wild-type TFA-hydrolyzable glucan contents, but reduced Updegraff cellulose contents and higher than wild-type cellulose crystallinity indices. The data support the hypothesis that PttCel9A1/KOR1 activity is present in cell walls, where it facilitates cellulose biosynthesis in a way that increases the amount of non-crystalline cellulose.
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| 7. |
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| 8. |
- Allsopp, Benjamin, et al.
(author)
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Towards improved cover glasses for photovoltaic devices
- 2020
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In: Progress in Photovoltaics. - : John Wiley and Sons Ltd. - 1062-7995 .- 1099-159X. ; 28, s. 1187-1206
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Journal article (peer-reviewed)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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| 9. |
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| 10. |
- Andersdotter, Amelia, et al.
(author)
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Godtyckligt regelverk hotar friheten på nätet
- 2013
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In: Dagens Nyheter. - 1101-2447. ; :2013-09-03
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Journal article (pop. science, debate, etc.)abstract
- Reglerna som möjliggör stängning av hemsidor på internet präglas av godtycke och otydlighet. Men det behöver inte vara särskilt svårt att skapa ett nytt och rättssäkert regelverk. Här har Sveriges EU-kommissionär Cecilia Malmström en viktig roll. Frågan är om hon tar sitt ansvar, skriver politiker och nätdebattörer.
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| 11. |
- Andersson, Anders, et al.
(author)
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A transcriptional timetable of autumn senescence
- 2004
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In: Genome Biology. - : Springer Science and Business Media LLC. - 1465-6906 .- 1474-760X. ; 5:4, s. R24-
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Journal article (peer-reviewed)abstract
- Background We have developed genomic tools to allow the genus Populus (aspens and cottonwoods) to be exploited as a full-featured model for investigating fundamental aspects of tree biology. We have undertaken large-scale expressed sequence tag (EST) sequencing programs and created Populus microarrays with significant gene coverage. One of the important aspects of plant biology that cannot be studied in annual plants is the gene activity involved in the induction of autumn leaf senescence. Results On the basis of 36,354 Populus ESTs, obtained from seven cDNA libraries, we have created a DNA microarray consisting of 13,490 clones, spotted in duplicate. Of these clones, 12,376 (92%) were confirmed by resequencing and all sequences were annotated and functionally classified. Here we have used the microarray to study transcript abundance in leaves of a free-growing aspen tree (Populus tremula) in northern Sweden during natural autumn senescence. Of the 13,490 spotted clones, 3,792 represented genes with significant expression in all leaf samples from the seven studied dates. Conclusions We observed a major shift in gene expression, coinciding with massive chlorophyll degradation, that reflected a shift from photosynthetic competence to energy generation by mitochondrial respiration, oxidation of fatty acids and nutrient mobilization. Autumn senescence had much in common with senescence in annual plants; for example many proteases were induced. We also found evidence for increased transcriptional activity before the appearance of visible signs of senescence, presumably preparing the leaf for degradation of its components.
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| 12. |
- Andersson-Gunneras, S., et al.
(author)
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Biosynthesis of cellulose-enriched tension wood in Populus : global analysis of transcripts and metabolites identifies biochemical and developmental regulators in secondary wall biosynthesis
- 2006
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In: The Plant Journal. - Malden : Wiley-Blackwell. - 0960-7412 .- 1365-313X. ; 45:2, s. 144-165
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Journal article (peer-reviewed)abstract
- Stems and branches of angiosperm trees form tension wood (TW) when exposed to a gravitational stimulus. One of the main characteristics of TW, which distinguishes it from normal wood, is the formation of fibers with a thick inner gelatinous cell wall layer mainly composed of crystalline cellulose. Hence TW is enriched in cellulose, and deficient in lignin and hemicelluloses. An expressed sequence tag library made from TW-forming tissues in Populus tremula (L.) x tremuloides (Michx.) and data from transcript profiling using microarray and metabolite analysis were obtained during TW formation in Populus tremula (L.) in two growing seasons. The data were examined with the aim of identifying the genes responsible for the change in carbon
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| 13. |
- Andersson, Matilda L., et al.
(author)
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Chasing away accurate results : exhaustive chase protocols underestimate maximum metabolic rate estimates in European perch Perca fluviatilis
- 2020
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In: Journal of Fish Biology. - : Wiley. - 0022-1112 .- 1095-8649. ; 97:6, s. 1644-1650
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Journal article (peer-reviewed)abstract
- Metabolic rates are one of many measures that are used to explain species' response to environmental change. Static respirometry is used to calculate the standard metabolic rate (SMR) of fish, and when combined with exhaustive chase protocols it can be used to measure maximum metabolic rate (MMR) and aerobic scope (AS) as well. While these methods have been tested in comparison to swim tunnels and chambers with circular currents, they have not been tested in comparison with a no‐chase control. We used a repeated‐measures design to compare estimates of SMR, MMR and AS in European perch Perca fluviatilis following three protocols: (a) a no‐chase control; (b) a 3‐min exhaustive chase; and (c) a 3‐min exhaustive chase followed by 1‐min air exposure. We found that, contrary to expectations, exhaustive chase protocols underestimate MMR and AS at 18°C, compared to the no‐chase control. This suggests that metabolic rates of other species with similar locomotorty modes or lifestyles could be similarly underestimated using chase protocols. These underestimates have implications for studies examining metabolic performance and responses to climate change scenarios. To prevent underestimates, future experiments measuring metabolic rates should include a pilot with a no‐chase control or, when appropriate, an adjusted methodology in which trials end with the exhaustive chase instead of beginning with it.
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| 14. |
- Aspeborg, Henrik, et al.
(author)
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Carbohydrate-active enzymes involved in the secondary cell wall biogenesis in hybrid aspen
- 2005
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In: Plant Physiology. - : Oxford University Press (OUP). - 0032-0889 .- 1532-2548. ; 137:3, s. 983-997
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Journal article (peer-reviewed)abstract
- Wood formation is a fundamental biological process with significant economic interest. While lignin biosynthesis is currently relatively well understood, the pathways leading to the synthesis of the key structural carbohydrates in wood fibers remain obscure. We have used a functional genomics approach to identify enzymes involved in carbohydrate biosynthesis and remodeling during xylem development in the hybrid aspen Populus tremula x tremuloides. Microarrays containing cDNA clones from different tissue-specific libraries were hybridized with probes obtained from narrow tissue sections prepared by cryosectioning of the developing xylem. Bioinformatic analyses using the sensitive tools developed for carbohydrate-active enzymes allowed the identification of 25 xylem-specific glycosyltransferases belonging to the Carbohydrate-Active EnZYme families GT2, GT8, GT14, GT31, GT43, GT47, and GT61 and nine glycosidases (or transglycosidases) belonging to the Carbohydrate-Active EnZYme families GH9, GH10, GH16, GH17, GH19, GH28, GH35, and GH51. While no genes encoding either polysaccharide lyases or carbohydrate esterases were found among the secondary wall-specific genes, one putative O-acetyltransferase was identified. These wood-specific enzyme genes constitute a valuable resource for future development of engineered fibers with improved performance in different applications.
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| 15. |
- Berg, Ulrika, et al.
(author)
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Lack of sex differences in the IGF-IGFBP response to ultra endurance exercise.
- 2008
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In: Scandinavian Journal of Medicine and Science in Sports. - : Wiley. - 0905-7188 .- 1600-0838. ; 18:6, s. 706-714
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Journal article (peer-reviewed)abstract
- The insulin-like growth factor (IGF)-IGF binding proteins (BP) and the pituitary-gonadal axes were investigated during ultra endurance exercise in 16 endurance-trained athletes (seven women). Median duration of the race was 6.3 days. Although food and drink were ad libitum, energy balance was negative. Blood samples were drawn before (PRE), at the end of (END) and 24 h after (POST24h) the race. Serum concentrations of total IGF-I (t-IGF-I) and free IGF-I (f-IGF-I) decreased by 33 (SD 38)% and 54 (19)%, respectively. The decrease in t-IGF-I appeared to be associated to the total energy deficit during the race. At END, the IGFBP-3 fragmentation and IGFBP-1 were increased but these changes did not predict changes in f-IGF-I. An increase in POST24h IGFBP-2 levels in women was the only sex difference. Testosterone was decreased by 67 (12)% in the men and estradiol became undetectable in the women without any detectable increase in LH and/or FSH. In conclusion ultra endurance exercise results in similar IGF-IGFBP responses in men and women reflecting a catabolic state. IGFBP-2 was the only exception, with increased levels in women after exercise. A concomitant decrease in gonadal hormones was not related to endocrine changes in the IGF-IGFBP axis but may be related to local changes in IGF-I expression.
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| 16. |
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| 17. |
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| 18. |
- Colwill, Karen, et al.
(author)
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A roadmap to generate renewable protein binders to the human proteome
- 2011
-
In: Nature Methods. - : Nature America Inc.. - 1548-7091 .- 1548-7105. ; 8:7, s. 551-8
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Journal article (peer-reviewed)abstract
- Despite the wealth of commercially available antibodies to human proteins, research is often hindered by their inconsistent validation, their poor performance and the inadequate coverage of the proteome. These issues could be addressed by systematic, genome-wide efforts to generate and validate renewable protein binders. We report a multicenter study to assess the potential of hybridoma and phage-display technologies in a coordinated large-scale antibody generation and validation effort. We produced over 1,000 antibodies targeting 20 SH2 domain proteins and evaluated them for potency and specificity by enzyme-linked immunosorbent assay (ELISA), protein microarray and surface plasmon resonance (SPR). We also tested selected antibodies in immunoprecipitation, immunoblotting and immunofluorescence assays. Our results show that high-affinity, high-specificity renewable antibodies generated by different technologies can be produced quickly and efficiently. We believe that this work serves as a foundation and template for future larger-scale studies to create renewable protein binders.
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| 19. |
- De Man, Jeroen, et al.
(author)
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Diabetes self-management in three different income settings : Cross-learning of barriers and opportunities
- 2019
-
In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 14:3
-
Journal article (peer-reviewed)abstract
- The burden of type 2 diabetes is increasing rapidly, not least in Sub-Saharan Africa, and disadvantaged populations are disproportionally affected. Self-management is a key strategy for people at risk of or with type 2 diabetes, but implementation is a challenge. The objective of this study is to assess the determinants of self-management from an implementation perspective in three settings: two rural districts in Uganda, an urban township in South Africa, and socio-economically disadvantaged suburbs in Sweden. Data collection followed an exploratory multiple-case study design, integrating data from interviews, focus group discussions, and observations. Data collection and analysis were guided by a contextualized version of a transdisciplinary framework for self-management. Findings indicate that people at risk of or with type 2 diabetes are aware of major self-management strategies, but fail to integrate these into their daily lives. Depending on the setting, opportunities to facilitate implementation of self-management include: improving patient-provider interaction, improving health service delivery, and encouraging community initiatives supporting self-management. Modification of the physical environment (e.g. accessibility to healthy food) and the socio-cultural environment (i.e. norms, values, attitudes, and social support) may have an important influence on people's lifestyle. Regarding the study methodology, we learned that this innovative approach can lead to a comprehensive analysis of self-management determinants across different settings. An important barrier was the difficult contextualization of concepts like perceived autonomy and self-efficacy. Intervention studies are needed to confirm whether the pathways suggested by this study are valid and to test the proposed opportunities for change.
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| 20. |
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| 21. |
- Echternach, Matthias, et al.
(author)
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Resonatory Properties in Professional Tenors Singing Above the Passaggio
- 2016
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In: Acta Acoustica united with Acustica. - 1610-1928 .- 1861-9959. ; 102:2, s. 298-306
-
Journal article (peer-reviewed)abstract
- Introduction: The question of formant tuning in male professional voices has been a matter of discussion for many years. Material and Methods: In this study four very successful Western classically trained tenors of different repertoire were analysed. They sang a scale on the vowel conditions /a,e,i,o,u/ from the pitch C4 (250 Hz) to A4 (440 Hz) in their stage voice avoiding a register shift to falsetto. Formant frequencies were calculated from inverse filtering of the audio signal and from two-dimensional MRI data. Results: Both estimations showed only for vowel conditions with low first formant (F1) a tuning F1 adjusted to the first harmonic. For other vowel conditions, however, no clear systematic formant tuning was observed. Conclusion: For most vowel conditions the data are not able to support the hypothesis of a systematic formant tuning for professional classically trained tenors.
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| 22. |
- Edén, Mattias, et al.
(author)
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The split network analysis for exploring composition-structure correlations in multi-component glasses : II. Multinuclear NMR studies of alumino-borosilicates and glass-wool fibers
- 2011
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In: Journal of Non-Crystalline Solids. - : Elsevier BV. - 0022-3093 .- 1873-4812. ; 357:6, s. 1587-1594
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Journal article (peer-reviewed)abstract
- The preceding part [M. Edén, J. Non.-Cryst. Solids, 357, (2011) 1595-1602] introduced the "split network" strategy for estimating the network polymerization degree (r A) and mean number of bridging oxygen (BO) atoms (N̄BOA) for a network former A, given that these parameters are known for all other network builders in the multi-component oxide glass. However, as the detailed ordering of BO and non-bridging oxygen (NBO) species is often difficult to assess experimentally, we summarize some "rules of thumb" for predicting the coordination number and tendency to accept NBO ions for Al 3+, B 3+, Si 4+ and P 5+ cations: they are helpful in scenarios devoid of experimental data. Using the parameters r and N̄BO, we present expressions for the BO/NBO distributions among tetrahedrally coordinated cations, as predicted from the binary and random models. Multinuclear 11B, 27Al and 29Si solid-state NMR is exploited to derive the split network representations of a set of Na-Ca-(Al)-(B)-Si-O glasses. These results are subsequently used to gain structural insight into two commercial glass-wool fibers that constitute alumino-borosilicate networks modified by Na +, K +, Ca 2+ and Mg 2+ ions. © 2010 Elsevier B.V.
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| 23. |
- Edler, David, et al.
(author)
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The expression of the novel CYP2W1 enzyme is an independent prognostic factor in colorectal cancer : a pilot study.
- 2009
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In: European Journal of Cancer. - : Elsevier BV. - 0959-8049 .- 1879-0852. ; 45:4, s. 705-712
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Journal article (peer-reviewed)abstract
- AIM Cytochrome P450 (CYP) enzymes are important for drug metabolism. A novel cytochrome P450 enzyme, CYP2W1, has recently been identified. This enzyme is mainly found in foetal colon tissue and in tumour tissue. In this pilot study, we have investigated the expression of CYP2W1 in 162 tumours from patients with stages II and III colorectal cancer. METHODS The expression of CYP2W1 enzyme was immunohistochemically detected using a polyclonal antibody. Staining intensity was defined using a visual grading scale from 0 to 3. Grades 0-2 were classified as low, and grade 3 was classified as high expression of CYP2W1. RESULTS About 64% of the tumours expressed a low level of CYP2W1-expression, and 36% expressed a high level. CYP2W1-expression was an independent prognostic factor for overall survival (p=0.007), where a high expression was associated with a worse clinical outcome. CONCLUSIONS Immunohistochemically assessed expression of CYP2W1 is an independent prognostic factor in patients with stages II and III colorectal cancer.
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| 24. |
- Edlund, Peter, 1986-
(author)
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Constructing an Arbiter of Status : A Study of the European Research Council's Emergence in the Field of Science
- 2018
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Doctoral thesis (other academic/artistic)abstract
- The aim of this thesis is to shed light on how certain actors are constructed into third-party arbiters of status. Such arbiters mediate the triadic relations in which status is created, assessing and suggesting certain candidates as particularly worthy of deference from audiences.While previous literature has provided us with compelling insights into the pervasive authority of status arbiters, less attention has been paid to the ways in which these arbiters reach their authoritative positions. I seek to build new knowledge on the processes through which third-party status arbiters are constructed by exploring how the European Research Council (ERC) was transformed into an authority in science. In a short period of time, the ERC’s evaluations of funding applications and subsequent allocations of research resources came to be approached as a benchmark of scientific quality, which scientists, departments, universities, and countries anxiously compared their research performance with. I suggest that these evaluations and allocations soon became more than instances in which quality was assessed and resources were distributed, thus turning into potent bases for status creation as well.In three empirical chapters, which draw upon documents, interviews, and observations, I place the ERC within the context of a field, showing how its construction into a third-party status arbiter needs to be understood as a process that unfolded over time. First, I look at major tensions and struggles that surrounded Europe-level science in the advent of the ERC’s founding. Then, I examine the active efforts with which the ERC attempted to engender acceptance for its evaluations of Starting Grant (StG) funding applications. Finally, I explore the status consequences of ERC StG allocations for the careers of scientists, the milieus within departments, and the relations between universities in Sweden.My findings contribute to previous literature by demonstrating how arbiters are constructed through mutually reinforcing relations in which the status-creating potential of evaluations is continuously framed and validated. My findings also contribute by showing how the creation of status over time requires constant maintenance efforts to sustain the agreement between arbiters and audiences in terms of candidates that are worthy of deference.
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| 25. |
- Eriksson, Cecilia, et al.
(author)
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Microfluidic analysis of antibody specificity in a compact disk format
- 2006
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In: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 5:7, s. 1568-1574
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Journal article (peer-reviewed)abstract
- A new and flexible technology for high throughput analysis of antibody specificity and affinity is presented. The method is based on microfluidics and takes advantage of compact disks (CDs) in which the centrifugal force moves fluids through microstructures containing immobilized metal affinity chromatography columns. Analyses are performed as a sandwich assay, where antigen is captured to the column via a genetically attached His(6)-tag. The antibodies to be analyzed are applied onto the columns. Thereafter, fluorescently labeled secondary antibodies recognize the bound primary antibodies, and detection is carried out by laser-induced fluorescence. The CDs contain 104 microstructures enabling analysis of antibodies against more than 100 different proteins using a single CD. Importantly, through the three- dimensional visualization of the binding patterns in a column it is possible to separate high affinity from low affinity binding. The method presented here is shown to be very sensitive, flexible and reproducible.
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| 26. |
- Fetisova, Ekaterina
(author)
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Evaluation of climate model simulations by means of statistical methods
- 2015
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Licentiate thesis (other academic/artistic)abstract
- Evaluation of climate model simulations is a key issue within climate research. The statistical framework proposed by Sundberg et al., 2012, provides a theoretical underpinning of methods for evaluation of climate models by use of climateproxy data from the last millennium. In the present work, the statistical framework above is used to suggest several latent factor models of different complexity that can be used for estimating the amplitude of a forcing effect in aclimate model by comparison with the observed/reconstructed climate. The performance of the models is evaluated and compared in a pseudo-proxy experiment, in which the true unobservable temperature series is replaced by selected realizations of a climate simulation model. For different levels of added noise, different conclusions can be drawn. However, for realistic noise levels, we find that the simplest model, the just-identified two-indicator one-factor model, denoted j.i.FA(2,1), is a competitive alternative to models with more complicated structure. Moreover, we discover that the Fieller method of constructing confidence regions, associated with the j.i.FA(2,1)-model, outperforms the Wald confidence interval, which in most cases fails to provide sensible and interpretable conclusions about the climate model under consideration. Last but not least, the results indicate a good performance of the j.i.FA(2,1)-model even in the presence of heteroscedasticity.
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| 27. |
- Gantelius, Jesper, et al.
(author)
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A ten-minute high density lateral flow protein microarray assay
- 2011
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In: 15th International Conference on Miniaturized Systems for Chemistry and Life Sciences 2011. - 9781618395955 ; , s. 1176-1178
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Conference paper (peer-reviewed)abstract
- Protein microarrays are useful tools for highly multiplexed determination of presence or levels of clinically relevant biomarkers in human tissues and biofluids. However, such tools have thus far been restricted to laboratory environments. Here, we present a novel 384-plexed easy to use lateral flow protein microarray device capable of sensitive (<50ng/ml) determination of antigen specific antibodies in less than ten minutes total assay time. Results were developed with gold nanobeads and could be recorded by a cell-phone camera or table top scanner. Excellent accuracy (AUC=99.4%) was achieved in comparison with an established glass microarray assay for 26 antigen-specific antibodies.
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| 28. |
- Gospic, Katarina, et al.
(author)
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Altruism costs-the cheap signal from amygdala
- 2014
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In: Social Cognitive & Affective Neuroscience. - : Oxford University Press (OUP). - 1749-5016 .- 1749-5024. ; 9:9, s. 1325-1332
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Journal article (peer-reviewed)abstract
- When people state their willingness to pay for something, the amount usually differs from the behavior in a real purchase situation. The discrepancy between a hypothetical answer and the real act is called hypothetical bias. We investigated neural processes of hypothetical bias regarding monetary donations to public goods using fMRI with the hypothesis that amygdala codes for real costs. Real decisions activated amygdala more than hypothetical decisions. This was observed for both accepted and rejected proposals. The more the subjects accepted real donation proposals the greater was the activity in rostral anterior cingulate cortex-a region known to control amygdala but also neural processing of the cost-benefit difference. The presentation of a charitable donation goal evoked an insula activity that predicted the later decision to donate. In conclusion, we have identified the neural mechanisms underlying real donation behavior, compatible with theories on hypothetical bias. Our findings imply that the emotional system has an important role in real decision making as it signals what kind of immediate cost and reward an outcome is associated with.
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| 29. |
- Granqvist, Svante, et al.
(author)
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The front and sub-lingual cavities in coronal stops : An acoustic approach to volume estimation
- 2003
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In: Proceedings of the XVth International Congress of Phonetic Sciences, Barcelona. ; , s. 941-944
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Journal article (peer-reviewed)abstract
- The subapical cavity has been shown to play a significant role in determining the F-patterns of articulations made with a raised tongue blade. This paper reports quantitative data on subapical volumes for Swedish dental and retroflex voiced stops. These estimates were made by means of an acoustic method using pulse excitation of the front cavity. EPG was employed to determine the place of articulation of the consonants. Front cavity volumes were found to vary in an approximately linear fashion as a function of place of articulation. For retroflex consonants, volumes ranged between 2 and 11 cm3. A lawful second-order effect was observed with front vowel contexts tending to shift the pattern towards smaller, and back vowels towards larger volumes.
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| 30. |
- Grund Bäck, Lina, et al.
(author)
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Improved mechanical properties and chemical durability by modifying the float glass composition and thermo-chemical strengthening for photovoltaic cover glass
- 2017
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Conference paper (peer-reviewed)abstract
- Solar energy is promising renewable energy where glass is an important material and have a significant impact on the efficiency of the photovoltaic (PV) module. The cover glass of PV-modules constitutes a large part of the total weight of the unit. In a recent Solar-ERA.NET project, LIMES (www.limes.nu), have we been aiming towards developing 1 mm thin glass for PV modules by improving the indentation mechanical properties and by investigating a novel thermo-chemical strengthening method.Starting from traditional soda-lime-silicate float composition different components was studied in a DoE fashion. The mechanical properties were studied using nano- and microindentation, the chemical durability by P98 analysis and weathering experiments. The findings resulted in a suggested composition for improving the properties of float glass by adding small amounts of zinc and titanium oxide as well as increasing the amount of aluminum and magnesium oxide. The components found to improve the chemical resistance were alumina, zirconia, zinc, lanthanum and titanium oxide. The surface hardness, crack- and scratch resistance were improved when magnesia was replaced with zinc oxide. When magnesia was replaced with titania, the hardness was increased.Some results from the thermo-chemical strengthening experiments will be presented. Heating and quenching in a reactive gas atmosphere using aluminum precursors have resulted in chemically modified surface in addition to the thermal strengthening.
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| 31. |
- Guadagnino, E., et al.
(author)
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A collaborative study into the determination of boron in glass using x-ray fluorescence (XRF) spectroscopy
- 2006
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In: Glass Technology: European Journal of Glass Science and Technology Part A. - 1753-3554. ; 47:4, s. 103-111
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Journal article (peer-reviewed)abstract
- XRF spectrometry is extensively used for production factory control because of its high precision and rapidity of response. For very accurate boron determinations in glass, classical wet chemical methods are still the preferred method of choice as the x-ray irradiation of light elements produces only a weak fluorescent response. However, the new generation XRF instruments employing enhanced matrix correction models plus the greater availability of certified reference materials may significantly improve the analytical performance of XRF spectrometers for the determination of "difficult" elements like boron.
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| 32. |
- Guadagnino, E., et al.
(author)
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A collaborative study on the determination of hexavalent chromium in container glasses : A report of ICGITC2 "Chemical Durability and Analysis"
- 2001
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In: Glass Technology. - 1753-3554. ; 42:6, s. 148-152
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Journal article (peer-reviewed)abstract
- Enforcement of the Packaging Directive 62194 has required the development of reliable reference methods for the determination of heavy metals in glass. After considering Pb, Cd and Hg TC2 has undertaken a collaborative study for the determination of hexavelent chromium. In this recommended procedure the glass sample is digested with a mixture of sulphuric acid and ammonium hydrogen fluoride at room temperature, then diphenylcarbazide is added to form a violet complex which is measured with a spectrophotometer. Decomposition efficiency, matrix effect and interferences produced by foreign ions are discussed. For container glasses of common production no alteration of the chromium valence state was highlighted due to the dissolution process. This is not assured for glasses containing other redox pairs that should be examined case by case. The final round robin conducted on a glass containing given amounts of barium, did not reveal any significant absorption of hexavalent chromium on the low soluble salts that are formed during the dissolution process. The method is sensible down to 2 mgCr6+/kg of glass.
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| 33. |
- Guadagnino, E., et al.
(author)
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Influence of some parameters on the approximation of European Pharmacopoeia and ISO Standard 4802 : Reasons for harmonization - a collaborative study of ICG/TC2, `Chemical Durability and Analysis'
- 2000
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In: Glass Technology. - 1753-3554. ; 41:3, s. 91-98
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Journal article (peer-reviewed)abstract
- The most widely used Standards to test the inner surface of glass containers for pharmaceutical use, European Pharmacopoeia and ISO 4802, may differ significantly in the results because of relevant differences in the procedures. In this study the rinsing procedures, effect of prolonging the cooling time to 95 °C, as prescribed by EN norms on safe operation practice, and the combination of the two factors were investigated. Nine laboratories participated in the collaborative study, the resulting extract solutions were analyzed both by titration and flame photometry. Results were evaluated by two way ANOVA with the aim of estimating three sources of variation: between procedures, between laboratories and random variation due to experimental error. For soda-lime-silica glass there is evidence that the different procedures influence the hydrolytic resistance of the inner surface of glass containers whichever method is used. Differences between laboratories were, however, much greater and results vary more due to which laboratory conducted the measurement rather than which procedure is employed. For borosilicate glass variations between procedures were found not to be significant. It is strongly recommended that ISO and EP shall adopt measures to minimize those factors that proved to exert great influence on reproducibility of results.
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| 34. |
- Gummesson, Sara, et al.
(author)
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Lithic Raw Material Economy in the Mesolithic : Experimental Test of Edged Tool Efficiency and Durability in Bone Tool Production
- 2017
-
In: Lithic Technology. - : Informa UK Limited. - 0197-7261 .- 2051-6185. ; 42:4, s. 140-154
-
Journal article (peer-reviewed)abstract
- The foundation of this paper is lithic economy with a focus on the actual use of different lithic raw materials for tasks at hand. Our specific focus is on the production of bone tools during the Mesolithic. The lithic and osseous assemblages from Strandvägen, Motala, in east-central Sweden provide the archaeological background for the study. Based on a series of experiments we evaluate the efficiency and durability of different tool edges of five lithic raw materials: Cambrian flint, Cretaceous flint, mylonitic quartz, quartz, and porphyry, each used to whittle bone. The results show that flint is the most efficient of the raw materials assessed. Thus, a non-local raw material offers complements of functional characteristics for bone working compared to locally available quartz and mylonitic quartz. This finding provides a new insight into lithic raw material distribution in the region, specifically for bone tool production on site.
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| 35. |
- Haikonen, Kalle, 1978-
(author)
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Underwater radiated noise from Point Absorbing Wave Energy Converters : Noise Characteristics and Possible Environmental Effects
- 2014
-
Doctoral thesis (other academic/artistic)abstract
- The conversion of wave energy into electrical energy has the potential to become a clean and sustainable form of renewable energy conversion. However, like all forms of energy conversion it will inevitably have an impact on the marine environment, although not in the form of emissions of hazardous substances (gases, oils or chemicals associated with anticorrosion). Possible environmental issues associated with wave energy conversion include electromagnetic fields, alteration of sedimentation and hydrologic regimes and underwater radiated noise.Underwater noise has the potential to propagate over long distances and thus have the potential to disturb marine organisms far away from the noise source. There is great variation in the ability to perceive sound between marine organisms, one sound that is clearly audible to one species can be completely inaudible to another. Thus, to be able to determine potential environmental impact from WECs associated with underwater noise, the noise radiated from the WECs must be known. This thesis presents results from studies on the underwater radiated noise from four different full-scale WECs in the Lysekil Wave Power Project.Hydrophones were used to measure the underwater radiated noise from operating point absorbing linear WECs. The main purpose was to study the radiated noise from the operating WECs with emphasis on characteristics such as spectrum levels, Sound Pressure Level (SPL), noise duration and repetition rate. This to be able to determine the origin of the noise and if possible, implement design changes to minimize radiated noise.The results identified two main operational noises (transients with the bulk of the energy in frequencies <1 kHz). The SPL of the radiated noise fluctuated significantly, depending on wave height. Broadband SPLrms of the measurements ranged between ~110 dB and ~140 dB re 1 µPa and SPLpeak of specific noises ranges between ~140 and ~180 dB re µPa. Audibility was estimated range from 1km to 15 km depending critically on species and on assumptions of propagation loss. The noise is not expected to have any negative effects on behaviour or mask any signals, unless in the vicinity (<150m) of the WECs in significant wave heights. No physical damage, even in close vicinity are expected on either fish or marine mammals.Having the aim to have as little impact on the environment a possible, these studies are important. This way precautions can be implemented early in the technical development of this kind of renewable energy converters. The benefits from the WECs the Lysekil wave power project are believed to outweigh possible environmental impacts due to underwater radiated noise.
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| 36. |
- Hansson, Markus, et al.
(author)
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A phase 1 dose-escalation study of antibody BI-505 in relapsed/refractory multiple myeloma.
- 2015
-
In: Clinical Cancer Research. - 1078-0432. ; 21:12, s. 2730-2736
-
Journal article (peer-reviewed)abstract
- Purpose: This multicenter, first-in-human study evaluated safety, tolerability, pharmacokinetics, and pharmacodynamics of BI-505, a human anti-ICAM-1 monoclonal antibody, in advanced relapsed/refractory multiple myeloma patients. Experimental design: BI-505 was given intravenously, every two weeks, at escalating doses from 0.0004 to 20 mg/kg, with extension of therapy until disease progression for responding or stable patients receiving 0.09 mg/kg or higher doses. Results: A total of 35 patients were enrolled. The most common adverse events were fatigue, pyrexia, headache, and nausea. Adverse events were generally mild to moderate and those attributed to study medication were mostly limited to the first dose, and manageable with premedication and slower infusion. No maximum tolerated dose was identified. BI-505's half-life increased with dose while clearance decreased, suggesting target-mediated clearance. The ICAM-1 epitopes on patient bone marrow myeloma were completely saturated at 10 mg/kg doses. Using the International Myeloma Working Group criteria, seven patients on extended therapy had stable disease for more than two months. Conclusion: BI-505 can be safely administered at doses that saturate myeloma cell ICAM-1 receptors in patients. This study was registered at www.clinicaltrials.gov (NCT01025206).
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| 37. |
- Hedberg, Petter, et al.
(author)
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A functional trait approach to fen restoration analysis
- 2013
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In: Applied Vegetation Science. - : Wiley. - 1402-2001 .- 1654-109X. ; 16:4, s. 658-666
-
Journal article (peer-reviewed)abstract
- Questions: Ecological restoration has traditionally been evaluated with analyses focused on species identities and abundances. These analyses provide no ecological explanation to why certain species change in abundance. One solution may be a functional trait analysis. We asked whether shifts in functional traits could explain vegetation changes in fens restored through tree cutting and rewetting, and how the functional traits in the restored sites compare to those of the reference site? Location: Three former rich fens in east-central Sweden. Methods: Tree cutting and rewetting were applied in a factorial design, and species and abundance data were recorded for 8yrs. Abundance data and trait data of canopy height, specific leaf area (SLA) and diaspore mass were used to calculate functional richness (FRic), functional divergence (FDiv), functional dispersion (FDis) and community-weighted mean (CWM) of functional traits. Data were analysed in a linear mixed effect model for vascular plants and bryophytes jointly, and for vascular plants separately. Results of restoration treatments were compared to data from a reference site. Results: Among vascular plants, tree cutting caused a decrease in SLA, as shade-sensitive species increased. In accordance with the change in SLA, FDis increased. In the joint analysis, tree cutting led to increased FDis, FDiv and FRic, indicating reduced filtering caused by the removal of the shading canopy, which allowed shade-sensitive species to establish. The comparison to the reference site shows that even after 8yrs, the restoration treatments have higher trait diversity than the reference site, indicating that the restoration sites have a too relaxed trait filter compared to conditions in an undisturbed fen. Our interpretation is that this is primarily caused by insufficient rewetting (and increased nutrient availability) that allow species of both natural and degraded fen conditions to co-exist, and which failed to suppress the regrowth of trees. Conclusions: Analysis of functional diversity improves our understanding of the ecological mechanisms affecting restoration results, and allows comparison among regions and communities with different species composition.
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| 38. |
- Hedberg, Petter, et al.
(author)
-
Vegetation recovery after multiple-site experimental fen restorations
- 2012
-
In: Biological Conservation. - : Elsevier BV. - 0006-3207 .- 1873-2917. ; 147:1, s. 60-67
-
Journal article (peer-reviewed)abstract
- Large peatland areas have been drained for forestry and agricultural purposes, resulting in the decline of characteristic biodiversity. Two measures commonly suggested for restoring drained fens is ditch blocking and tree removal to raise the groundwater table and increase light availability, respectively. In 2002, we initiated factorial restoration experiments, including ditch blocking and tree removal, in three former rich fens that had been drained for forestry purposes. Species cover of vascular plants and bryophytes were monitored during 8 years in permanent plots along transects perpendicular to the ditch for all four treatment combinations. Both methods had positive and independent effects on the cover of wetland vegetation. Specifically, Sphagnum species and wetland bryophytes showed a persistent positive response to both clear cutting and rewetting. Wetland vascular plants and grasses showed a persistent positive response to clear cutting. Sedges and species number responded positively to both clear cutting and ditch blocking, but the response was partly transient, and for species richness the response was limited when restoration methods were applied separately. Rich fen indicators of vascular plants and bryophytes did not respond to any of the restoration treatments. This indicates that species introduction in combination with further habitat restorations may be necessary to re-establish the original rich fen flora. Nevertheless, we conclude that the combination of ditch blocking and clear cutting are effective measures to partly restore wetland vegetation on previously drained and forested fens, while peat subsidence along the ditch may restrict the success further away from ditches.
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| 39. |
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| 40. |
- Hertzberg, M., et al.
(author)
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A transcriptional roadmap to wood formation
- 2001
-
In: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 98:25, s. 14732-14737
-
Journal article (peer-reviewed)abstract
- The large vascular meristem of poplar trees with its highly organized secondary xylem enables the boundaries between different developmental zones to be easily distinguished. This property of wood-forming tissues allowed us to determine a unique tissue-specific transcript profile for a well defined developmental gradient. RNA was prepared from different developmental stages of xylogenesis for DNA microarray analysis by using a hybrid aspen unigene set consisting of 2,995 expressed sequence tags. The analysis revealed that the genes encoding lignin and cellulose biosynthetic enzymes, as well as a number of transcription factors and other potential regulators of xylogenesis, are under strict developmental stage-specific transcriptional regulation.
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| 41. |
- Holmgren, Gustav, et al.
(author)
-
Long-Term Chronic Toxicity Testing Using Human Pluripotent Stem Cell-Derived Hepatocytes
- 2014
-
In: Drug Metabolism and Disposition. - : American Society for Pharmacology & Experimental Therapeutics (ASPET). - 0090-9556 .- 1521-009X. ; 42:9, s. 1401-1406
-
Journal article (peer-reviewed)abstract
- Human pluripotent stem cells (hPSC) have the potential to become important tools for the establishment of new models for in vitro drug testing of, for example, toxicity and pharmacological effects. Late-stage attrition in the pharmaceutical industry is to a large extent caused by selection of drug candidates using nonpredictive preclinical models that are not clinically relevant. The current hepatic in vivo and in vitro models show clear limitations, especially for studies of chronic hepatotoxicity. For these reasons, we evaluated the potential of using hPSC-derived hepatocytes for long-term exposure to toxic drugs. The differentiated hepatocytes were incubated with hepatotoxic compounds for up to 14 days, using a repeated-dose approach. The hPSC-derived hepatocytes became more sensitive to the toxic compounds after extended exposures and, in addition to conventional cytotoxicity, evidence of phospholipidosis and steatosis was also observed in the cells. This is, to the best of our knowledge, the first report of a long-term toxicity study using hPSC-derived hepatocytes, and the observations support further development and validation of hPSC-based toxicity models for evaluating novel drugs, chemicals, and cosmetics.
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| 42. |
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| 43. |
- Janzi, M., et al.
(author)
-
Serum microarrays for large scale screening of protein levels
- 2005
-
In: Molecular & Cellular Proteomics. - 1535-9476 .- 1535-9484. ; 4:12, s. 1942-1947
-
Journal article (peer-reviewed)abstract
- There is a great need for comprehensive proteomic analysis of large patient cohorts of plasma and serum samples to identify biomarkers of human diseases. Here we describe a new antibody-based proteomic approach involving a reverse array format where serum samples are spotted on a microarray. This enables all samples to be screened for their content of a certain serum protein in a single experiment using target-recognizing antibodies and fluorescently labeled secondary antibodies. The procedure is illustrated with the analysis of the IgA levels in 2009 spotted serum samples, and the data are compared with clinical routine measurements. The results suggest that it is possible to simultaneously screen thousands of complex clinical serum samples for their content of the relative amount of specific serum proteins of clinical relevance.
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| 44. |
- Johansson, Katarina, et al.
(author)
-
Celiac disease and upper secondary school achievement in Sweden : A retrospective cohort study
- 2022
-
In: BMC Pediatrics. - : BioMed Central (BMC). - 1471-2431. ; 22:1
-
Journal article (peer-reviewed)abstract
- BACKGROUND: Both undiagnosed celiac disease and some chronic childhood diseases are associated with lower academic achievement. However, there is little knowledge of achievements in those diagnosed with celiac disease. Our aim was to investigate school achievements in upper secondary school among Swedish adolescents with celiac disease.METHODS: We performed a retrospective cohort study using register data. We analyzed choice of upper secondary school program, completion of upper secondary school including achievements of basic eligibility for college/university, and final grade in individuals with celiac disease diagnosed before 15 years of age, born 1991-97. We compared with the Swedish population of the same birth years. Analyses were adjusted for sex, year of birth, living region at 17 years of age, and parental education as well as income.RESULTS: The cohort included 734 074 individuals, whereof 3 257 (62% females) with celiac disease. There was no significant difference in choice of upper secondary school program. No significant difference was found in completion or achieving basic eligibility for college/university in adjusted analyses. The mean final grade in the celiac disease group was 13.34 (standard deviation 4.85) compared to 12.78 (standard deviation 5.01) in the reference population (p < 0.001), out of a maximum of 20. The effect of celiac disease on final grade remained in adjusted analyses (p = 0.012).CONCLUSIONS: We found that diagnosed celiac disease does not negatively affect school achievements in upper secondary school. This finding suggests the diagnosis, treatment and follow-up programs of celiac disease could reverse potential deleterious academic processes.
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| 45. |
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| 46. |
- Karlberg, Martin, 1969-, et al.
(author)
-
Hemmasittare och vägen tillbaka: Insatser vid långvarig skolfrånvaro
- 2015. - 1
-
Book (pop. science, debate, etc.)abstract
- Att inte gå i skolan innebär ett stort lidande för den unge själv och för familjen runtomkring. Skolfrånvaro övergår ofta i arbetslöshet och utanförskap om inget görs. Det finns många goda skäl till att sätta in resurser tidigt för att hjälpa hemmasittare tillbaka till skolan. Boken Hemmasittare och vägen tillbaka beskriver ett arbetssätt som har hjälpt många elever tillbaka till skolan. Bakom metoden står Magelungen Utveckling AB som erbjuder kvalificerat behandlings- och förändringsarbete för barn, ungdomar, unga vuxna och deras familjer. Nu delar de med sig av sina erfarenheter till bland andra skolans elevhälsoteam, skolledare, BUP och engagerade föräldrar. Hemmasittare och vägen tillbaka tar bland annat upp:Hur kunde det bli så här och vad innebär det för elevens framtid?Vad kostar det att inte göra något?Inlärningsteori och beteendeanalysAtt få kunskap om problematikenAtt uppmuntra och förändra beteendenOm konsten att skapa allianser med elever, föräldrar, skolpersonalSamverkan och samordning en grundbult Kartläggning och att analysera information Förändringen steg för stegVidmakthållande, lika viktigt som alla föregående stegFörfattarna ger många praktiska tips, verkliga exempel och även formulär som behövs för insatserna. Hemmasittare och vägen tillbaka ger både en teoretisk, forskningsbaserad grund och är en praktisk handbok.
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| 47. |
- Karlsson, Anna, et al.
(author)
-
Impact of trace element addition on degradation efficiency of volatile fatty acids, oleic acid and phenyl acetate and on microbial populations in a biogas digester
- 2012
-
In: Journal of Bioscience and Bioengineering. - : Elsevier. - 1389-1723 .- 1347-4421. ; 114:4, s. 446-452
-
Journal article (peer-reviewed)abstract
- The effect of trace element addition on anaerobic digestion of food industry- and household waste was studied using two semi-continuous lab-scale reactors, one (R30+) was supplied with Fe, Co and Ni, while the other (R30) acted as a control. Tracer analysis illustrated that methane production from acetate proceeded through syntrophic acetate oxidation (SAO) in both digesters. The effect of the trace elements was also evaluated in batch assays to determine the capacity of the microorganisms of the two digesters to degrade acetate, phenyl acetate, oleic acid or propionate, butyrate and valerate provided as a cocktail. The trace elements addition improved the performance of the process giving higher methane yields during start-up and early operation and lower levels of mainly acetate and propionate in the R30+ reactor. The batch assay showed that material from R30+ gave effects on methane production from all substrates tested. Phenyl acetate was observed to inhibit methane formation in the R30 but not in the R30+ assay. A real-time PCR analysis targeting methanogens on the order level as well as three SAO bacteria showed an increase in Methanosarcinales in the R30+ reactor over time, even though SAO continuously was the dominating pathway for methane production. Possibly, this increase explains the low VFA-levels and higher degradation rates observed in the R30+ batch incubations. These results show that the added trace elements affected the ability of the microflora to degrade VFAs as well as oleic acid and phenyl acetate in a community, where acetate utilization is dominated by SAO.
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| 48. |
- Karlsson, Stefan, 1984-, et al.
(author)
-
Lätta Innovativa Material för Effektiva Solcellsmoduler (LIMES)
- 2017
-
Reports (other academic/artistic)abstract
- Utvinning av solenergi genom solceller är en lovande teknik för att öka andelen förnyelsebara energikällor både nu och i framtiden. Glas till solceller är en betydande del av kostnaden och en nödvändighet att utveckla för att öka livslängden och minska priset per utvunnen watt. I LIMES har man studerat dels att tillsätta optiskt aktiva komponenter som absorberar skadligt UV ljus och samtidigt konverterar det till synligt ljus som i sin tur kan konverteras till energi i solcellerna. Därmed är vinsten tvåfaldig, ökar både livslängden och effektiviteten med upp till 4%. Vidare har det studerats hur man kan optimera de mekaniska och kemiska egenskaperna av glas för att kunna öka den mekaniska och kemiska livslängden, detta genom att optimera glassammansättningen. Man har inom projektet visat att motstånd mot sprickbildning av en ny sammansättning ökar med en faktor 3 och att den kemiska resistensen ökar med en faktor 4. Termo-kemisk härdning av glas har demonstrerats i labskala som ger upphov till minst lika stor härdningsgrad samt ökar motstånd mot sprickbildning med en faktor 2. Det möjliggör användning av tunnare glas och därmed betydligt lättare solceller. Glasytans sammansättning modifieras signifikant genom att öka halten aluminiumoxid och det ger upphov till de förbättrade egenskaperna. Den termo-kemiska behandlingen ökar vattens kontaktvinkel mot glasytan vilket bidrar till ett självrengörande glas. Multifunktionella ytor på glas som är både antireflektiva och självrengörande har studerats genom två olika angreppssätt, nanostrukturerad ytmodifiering och porösa antireflektiva beläggningar med fotokatalytisk nedbrytningsförmåga. Nanostrukturerade glasytor ger upphov till en ökad ljusspridning och kan på så vis effektivt guida ner diffust ljus till solceller och samtidigt ändra vattens kontaktvinkel mot glaset. LIMES-koncepten har demonstrerats genom kvantitativa mätningar och tillverkande av små kiselsolcellsmoduler. Projektet har stått för att öka potentialen för kommersialisering ifrån TRL (Technology Readiness Level) nivå 2-4 till 4-6. Man undersöker i det närmaste hur man kan skala upp planglastillverkning för att kunna ta nästa steg mot kommersialisering.
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| 49. |
- Karlsson, Stefan, 1984-, et al.
(author)
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Surface analysis of float glass using surface ablation cell (SAC). : Part 2. Determination of the diffusion characteristics of K+-Na+ ion exchange
- 2010
-
In: Glass Technology: European Journal of Glass Science and Technology Part A. - 1753-3554. ; 51:2, s. 55-62
-
Journal article (peer-reviewed)abstract
- The surface ablation cell (SAC), a laboratory equipment for determining surface concentration profiles, has been utilised to characterise surface ion exchange processes in float glass. In this paper, single-side ion exchange is reported. Data on the ion concentration profiles were used to calculate diffusion coefficients as well as the activation energy for K +-Na+ ion exchange. The air-sides of float glass samples were treated with two different salt mixtures, (I) 2:1 KNO3:KCI, and (II) 1:2 KNO3:KCl, (both by weight), and heated to different temperatures below Tg, 460-520°C. The diffusion coefficients calculated using a Green's function approach were in the ranges (I) 1.4×10-11 to 6.8×10-11 and (II) 1.8×10-11 to 6.0×10-11 cm2/s while those calculated using Boltzmann-Matano were in the ranges (I) 5.7×10 -11 to 14×10-12 and (II) 3.4×10-12 to 6.0×10-12 cm2/s. Average values of the activation energies obtained through the Green's function were (I) 111.0 kJ/mol and (II) 99.8 kJ/mol for the different salt mixtures.
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| 50. |
- Karlsson, Stefan, 1984-, et al.
(author)
-
Surface Analysis of float glass using Surface Ablation Cell (SAC) Part 2: Determination of the diffusion characteristics of K+-Na+ ion exchange
- 2010
-
In: Glass Technology. - 0017-1050. ; 51:2, s. 55-62
-
Journal article (peer-reviewed)abstract
- The Surface Ablation Cell (SAC), a laboratory equipment for determining surface concentration profiles, has been utilised to characterise float glass surface ion exchange processes. In this paper, single-side ion exchange is reported. Data on the ion concentration profiles were used to calculate diffusion coefficients as well as the activation energy for K+-Na+ ion exchange. The air-sides of float glass samples were treated with two different salt mixtures, I) KNO3:KCl, 2:1 and II) KNO3:KCl, 1:2, and heated to different temperatures under Tg, 460-520 °C. The diffusion coefficients calculated with Green’s function were in the range I) 1.4x10-11 to 6.8x10-11 and II) 1.8x10-11 to 6.0x10-11 cm2/s while calculated according to Boltzmann-Matano I) 5.7x10-12 to 1.4x10-11 and II) 3.4x10-12 to 6.0x10-12 cm2/s. Average values of the activation energies obtained through Green’s function were I) 111.0 kJ/mol and II) 99.8 kJ/mol for the different salt mixtures.
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