| 1. |
- Waltermo, Å, et al.
(författare)
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Alkyl glucosides on hydrophobic surfaces studied by surface force and wetting measurements
- 1996
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Ingår i: Journal of Colloid and Interface Science. - 0021-9797 .- 1095-7103. ; 183, s. 506-514
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Tidskriftsartikel (refereegranskat)abstract
- The wetting properties of hydrophobized surfaces in the presence of alkyl glucosides have been studied using a Wilhelmy balance technique, and the interparticle forces acting between such surfaces have been investigated using the interferometric surface force apparatus. The adsorption at concentrations well below the cmc is rather limited both for the anomerically pure octyl b-glucoside and for the technical product based on the branched octyl glucoside, 2-ethylhexyl glucoside. However, the adsorption results in a decreasing surface hydrophobicity, and consequently the force needed to separate two such surfaces from each other is reduced. At the cmc for octyl b-glucoside, a surfactant monolayer is adsorbed on each surface. The interaction between the glucose units gives rise to a short-range repulsive force. Beyond the range of this repulsive force a weak attraction is experienced. Addition of a small amount of octyl a-glucoside does not change the short-range interaction significantly. The technical 2-ethylhexyl glucoside surfactant behaves similarly to the anomerically pure surfactant at low concentrations. The solution with the technical glucoside phase-separates at high surfactant concentration. It is observed that under such conditions a thick layer is deposited on each surface.
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| 2. |
- Adams, Emma, 1989, et al.
(författare)
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Water–gas-shift assisted ammonia formation over Pd/Ce/alumina
- 2018
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Ingår i: Catalysis Today. - : Elsevier BV. - 0920-5861. ; 307, s. 169-174
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Tidskriftsartikel (refereegranskat)abstract
- We report experimental results for the water–gas-shift assisted formation of ammonia from nitric oxide over alumina supported palladium, modified with various amounts (0–38 wt.%) of cerium. Static and transient flow reactor experiments were performed in order to identify the effects of temperature and the presence of oxygen on the activity for ammonia formation over the catalysts. The water–gas-shift reaction is enhanced with increasing cerium content, thus providing more hydrogen for ammonia formation. During transient operation at temperatures above 350 °C, a slight delay in ammonia formation is observed over the sample containing the highest cerium loading due to its (relatively) high dynamic oxygen storage capacity. At temperatures below 175 °C, N2O formation is preferred over NH3 formation. This work highlights the importance of balancing the effects that ceria influences when choosing the ceria loading for ammonia formation in passive-SCR applications.
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| 3. |
- Heyne, Stefan, 1979, et al.
(författare)
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Coal and biomass gasification for sng production
- 2016
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Ingår i: Synthetic Natural Gas from Coal and Dry Biomass, and Power?to?Gas Applications. - Hoboken, NJ, USA : John Wiley & Sons, Inc.. - 9781119191339 ; , s. 5-40
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Within the production of synthetic natural gas - basically methane-from solid feed stock such as coal or biomass the major conversion step is gasification, generating a product gas containing a mixture of permanent and condensable gases, as well as solid residues. The gasification step can be conducted in different atmospheres and using different reaction agents. This chapter discusses the role of gasification for the overall substitute natural gas (SNG) process, and the basic thermodynamic aspects within gasification. The gasification process is a series of different conversions involving both homogeneous and heterogeneous reactions. The basic steps from solid fuel to product gas are drying, pyrolysis, and gasification. From a technological viewpoint, there basically exist three different gasification reactor types that are used at large scale: fixed bed reactors, entrained flow reactors, and fluidized bed reactors. Coal is mainly used in entrained flow gasification or fixed bed units, whereas biomass gasification is mostly done in fluidized bed reactors. © 2016 by John Wiley & Sons, Inc. All rights reserved.
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| 4. |
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| 5. |
- Sassenhagen, Ingrid, et al.
(författare)
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Protist Interactions and Community Structure During Early Autumn in the Kerguelen region (Southern Ocean)
- 2019
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Ingår i: Protist. - : Elsevier BV. - 1434-4610 .- 1618-0941. ; 171:1
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated protist community composition and biotic interactions focusing on microplankton at four distinct sites around the Kerguelen Islands (Southern Ocean) after the summer phytoplankton bloom. Protist diversity in different size fractions, sampled with Niskin bottles and plankton nets, was assessed by sequencing of the V4 18S rDNA region. Combining different approaches, i.e. sequencing of different plankton size fractions, and isolation and sequencing of single cells, provided new insights into microbial interactions in protist communities. The communities displayed high variability, including short-term fluctuations in relative abundance of large protists (\textgreater35 µm) highlighted by the plankton net samples. Size fractionation of protist communities showed high concentrations of free Syndiniales spores but relatively few Syndiniales associated with microplankton, suggesting low parasitic infection in early autumn. Co-variance network analyses and sequencing of individually isolated single cells highlighted the important role of Rhizaria as consumers of a wide range of different diatom taxa. The data also raised the hypothesis that different Syndiniales clades might be directly or indirectly associated with some diatom genera, thus suggesting a potentially wider host range of these parasites than has been previously reported. These associations and the potential impact on carbon fluxes are discussed.
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| 6. |
- Wienberg, Jes, et al.
(författare)
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Europeanisation at the Baltic Sea : a Counterfactual Perspective
- 2009
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Ingår i: The Reception of Medieval Europe in the Baltic Sea Region : Papers of the XIIth Visby Symposium held at Gotland University, Visby - Papers of the XIIth Visby Symposium held at Gotland University, Visby. - 0065-1702. - 9197365351 ; 12, s. 421-429
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- A counterfactual perspective on the development at the Europeanisation at the Baltic Sea between 1100 and 1400.
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| 7. |
- Dillner, Lena, et al.
(författare)
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Randomized healthservices study of human papillomavirus-based management of low-grade cytological abnormalities.
- 2011
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; okt, s. 151-159
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Tidskriftsartikel (refereegranskat)abstract
- Human Papillomavirus (HPV)-based management of women with borderline (ASCUS) or mildly abnormal (CINI) cervical cytology has been extensively studied in the research setting. We wished to assess safety and healthcare resource use of a real-life healthcare policy using HPV triaging.All 15 outpatient clinics involved in the organized population-based screening program in Stockholm, Sweden screening program were randomized to either continue with prior policy (colposcopy of all women with ASCUS/CINI) or to implement a policy with HPV triaging and colposcopy only of HPV-positive women. The trial enrolled the 3319 women that were diagnosed with ASCUS (n=1335) or CINI (n=1984) in Stockholm during 17(th) March 2003 to 16(th) January 2006. Detection of high-grade cervical lesions (CINII+) and health care cost consumption was studied by registry linkages.The proportion of histopathology-verified CINII+ was similar for the 2 policies (395/1752 women (22.5%; 95% Confidence interval (CI): 20,6-24,6%) had CINII+ diagnosed with HPV triaging policy, 318/1567 women (20.3%; 95%CI: 18,3-22,4%)) had CINII+ with colposcopy policy). 64% of women with ASCUS and 77% of women with CINI were HPV-positive. HPV-positivity was age-dependent, with 81% of women below 35 years of age and 44% of women above 45 years of age testing HPV-positive. HPV triaging was cost-effective only above 35 years of age.In conclusion, a real-life randomised healthservices study of HPV triaging of women with ASCUS/CINI demonstrated similar detection of CINII+ as colposcopy of all women.
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| 8. |
- Francus, Pierre, et al.
(författare)
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The rise of varves
- 2013
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Ingår i: GFF. - : Informa UK Limited. - 1103-5897 .- 2000-0863. ; 135:3-4, s. 229-230
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Forskningsöversikt (refereegranskat)abstract
- Varves are exceptional in many aspects: they are rare, can be used to constrain and build chronologies, and contain highresolution records of past environment and climate. Moreover, their occurrence and reproducibility in different settings allows for an internal validation of their continuity and integrity. Gerard De Geer of Sweden understood the value of varved sediments over a century ago. Although other geologists during his time had described rhythmic, glacial lake sediments that they interpreted as annual layers (e.g. Smith 1832; Hitchcock 1841; Upham 1884), it was De Geer who saw the potential of varves (from the Swedish word varv, meaning cycle), for dating the retreat of the Scandinavian ice sheet, and by extension, the late Quaternary. And it was De Geer and his students who built the socalled Swedish Time Scale, which extends from the present to over 13,000 years before present. Much of De Geer’s early work was in fact published in GFF (e.g. De Geer 1908, 1921, 1935). However, De Geer’s considerations of teleconnections (today, a hot topic in climate research), along with strong reservations from North American geologists about the implications of the varve chronology in the Connecticut River valley by Ernst Antevs (one of De Geer’s ler-jungar; Antevs 1922, 1928), led many to doubt the annual nature of varves. Ages for the New England varves, based on the, at that time, new 14C technique, as well as varves’ similarities to the turbidites that Philip Kuenen was describing, convinced many that varves were not annual (for details, see Ridge and Larsen 1990; Ridge et al. 2012). Today, the varves that De Geer (as well as Antevs) looke
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| 9. |
- Heyne, Stefan, 1979, et al.
(författare)
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Exergy-based comparison of indirect and direct biomass gasification technologies within the framework of bio-SNG production
- 2013
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Ingår i: Biomass Conversion and Biorefinery. - : Springer Science and Business Media LLC. - 2190-6815 .- 2190-6823. ; 3:4, s. 337-352
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Tidskriftsartikel (refereegranskat)abstract
- Atmospheric indirect steam-blown and pressurised direct oxygen-blown gasification are the two major technologies discussed for large-scale production of synthetic natural gas from biomass (bio-SNG) by thermochemical conversion. Published system studies of bio-SNG production concepts draw different conclusions about which gasification technology performs best. In this paper, an exergy-based comparison of the two gasification technologies is performed using a simplified gasification reactor model. This approach aims at comparing the two technologies on a common basis without possible bias due to model regression on specific reactor data. The system boundaries include the gasification and gas cleaning step to generate a product gas ready for subsequent synthesis. The major parameter investigated is the delivery pressure of the product gas. Other model parameters include the air-to-fuel ratio for gasification as well as the H2/CO ratio in the product gas. In order to illustrate the thermodynamic limits and sources of efficiency loss, an ideal modelling approach is contrasted with a model accounting for losses in, e.g. the heat recovery and compression operations. The resulting cold-gas efficiencies of the processes are in the range of 0.66–0.84 on a lower heating value basis. Exergy efficiencies for the ideal systems are from 0.79 to 0.84 and in the range of 0.7 to 0.79 for the systems including losses. Pressurised direct gasification benefits from higher delivery pressure of the finished gas product and results in the highest exergy efficiency values. Regarding bio-SNG synthesis however, a higher energetic and exergetic penalty for CO2 removal results in direct gasification exergy efficiency values that are below values for indirect gasification. No significant difference in performance between the technologies can be observed based on the model results, but a challenge identified for process design is efficient heat recovery and cogeneration of electricity for both technologies. Furthermore, direct gasification performance is penalised by incomplete carbon conversion in contrast to performance of indirect gasification concepts.
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| 10. |
- Jia, Kai-Hua, et al.
(författare)
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Chromosome-scale assembly and evolution of the tetraploid Salvia splendens (Lamiaceae) genome
- 2021
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Ingår i: Horticulture Research. - : Oxford University Press (OUP). - 2052-7276 .- 2662-6810. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- Polyploidization plays a key role in plant evolution, but the forces driving the fate of homoeologs in polyploid genomes, i.e., paralogs resulting from a whole-genome duplication (WGD) event, remain to be elucidated. Here, we present a chromosome-scale genome assembly of tetraploid scarlet sage (Salvia splendens), one of the most diverse ornamental plants. We found evidence for three WGD events following an older WGD event shared by most eudicots (the γ event). A comprehensive, spatiotemporal, genome-wide analysis of homoeologs from the most recent WGD unveiled expression asymmetries, which could be associated with genomic rearrangements, transposable element proximity discrepancies, coding sequence variation, selection pressure, and transcription factor binding site differences. The observed differences between homoeologs may reflect the first step toward sub- and/or neofunctionalization. This assembly provides a powerful tool for understanding WGD and gene and genome evolution and is useful in developing functional genomics and genetic engineering strategies for scarlet sage and other Lamiaceae species.
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