| 1. |
- Hartmann, Michael, et al.
(författare)
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Non-contact protein microarray fabrication using a procedure based on liquid bridge formation
- 2009
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Ingår i: Analytical and Bioanalytical Chemistry. - : Springer Science and Business Media LLC. - 1618-2642 .- 1618-2650. ; 393:2, s. 591-598
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Tidskriftsartikel (refereegranskat)abstract
- Contemporary microarrayers of contact or noncontact format used in protein microarray fabrication still suffer from a number of problems, e. g. generation of satellite spots, inhomogeneous spots, misplaced or even absent spots, and sample carryover. In this paper, a new concept of non-contact sample deposition that reduces such problems is introduced. To show the potential and robustness of this pressure-assisted deposition technique, different sample solutions known to cause severe problems or to be even impossible to print with conventional microarrayers were accurately printed. The samples included 200 mg mL(-1) human serum albumin, highly concentrated sticky cell adhesion proteins, pure high-salt cell-lysis buffer, pure DMSO, and a suspension of 5-mu m polystyrene beads. Additionally, a water-immiscible liquid fluorocarbon, which was shown not to affect the functionality of the capture molecules, was employed as a lid to reduce evaporation during microarray printing. The fluorocarbon liquid lid was shown to circumvent hydrolysis of water-sensitive activated surfaces during long-term deposition procedures.
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| 2. |
- Moberg, Christina, et al.
(författare)
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De unga gör helt rätt när de stämmer staten
- 2022
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Ingår i: Aftonbladet. - 1103-9000.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- 1 620 forskare och lärare i forskarvärlden: Vi ställer oss bakom Auroras klimatkrav
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| 4. |
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| 6. |
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| 7. |
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| 8. |
- Bergemalm, Daniel, 1977-, et al.
(författare)
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Systemic Inflammation in Preclinical Ulcerative Colitis
- 2021
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Ingår i: Gastroenterology. - : AGA Institute. - 0016-5085 .- 1528-0012. ; 161:5, s. 1526-1539.e9
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Tidskriftsartikel (refereegranskat)abstract
- Background & Aims: Preclinical ulcerative colitis is poorly defined. We aimed to characterize the preclinical systemic inflammation in ulcerative colitis, using a comprehensive set of proteins.Methods: We obtained plasma samples biobanked from individuals who developed ulcerative colitis later in life (n = 72) and matched healthy controls (n = 140) within a population-based screening cohort. We measured 92 proteins related to inflammation using a proximity extension assay. The biologic relevance of these findings was validated in an inception cohort of patients with ulcerative colitis (n = 101) and healthy controls (n = 50). To examine the influence of genetic and environmental factors on these markers, a cohort of healthy twin siblings of patients with ulcerative colitis (n = 41) and matched healthy controls (n = 37) were explored.Results: Six proteins (MMP10, CXCL9, CCL11, SLAMF1, CXCL11 and MCP-1) were up-regulated (P < .05) in preclinical ulcerative colitis compared with controls based on both univariate and multivariable models. Ingenuity Pathway Analyses identified several potential key regulators, including interleukin-1β, tumor necrosis factor, interferon-gamma, oncostatin M, nuclear factor-κB, interleukin-6, and interleukin-4. For validation, we built a multivariable model to predict disease in the inception cohort. The model discriminated treatment-naïve patients with ulcerative colitis from controls with leave-one-out cross-validation (area under the curve = 0.92). Consistently, MMP10, CXCL9, CXCL11, and MCP-1, but not CCL11 and SLAMF1, were significantly up-regulated among the healthy twin siblings, even though their relative abundances seemed higher in incident ulcerative colitis.Conclusions: A set of inflammatory proteins are up-regulated several years before a diagnosis of ulcerative colitis. These proteins were highly predictive of an ulcerative colitis diagnosis, and some seemed to be up-regulated already at exposure to genetic and environmental risk factors.
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| 9. |
- Bonn, Jonas, et al.
(författare)
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Electrostatic Sample Nebulization for Improved Sample Vaporization in the Split/Splitless Gas Chromatography Inlet
- 2009
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 81:13, s. 5327-5332
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Tidskriftsartikel (refereegranskat)abstract
- The split/splitless inlet system has basically the same fundamental drawbacks it had when it was introduced: poor repeatability of the injected amount of sample and discrimination of high-boiling analytes. Hot needle injection improves the repeatability of the sample transfer but suffers from in-needle discrimination. Injection with a fast autosampler, resulting in minimal heating of the needle, solves this problem but usually requires a glass wool packing in the inlet liner to assist in vaporization of the sample. As glass wool has been reported to cause degradation of labile analytes, it cannot be applied as a general remedy for improving incomplete vaporization. In this paper, a novel concept, based on electrostatic nebulization of the injected sample, is presented. The resulting fine droplets promote a more effective heat transfer and a rapid vaporization. Evaluation of the electrospray inlet in the split mode, using a straight, empty glass liner and a cold needle, showed an improvement in peak area repeatability by about 1 order of magnitude, compared with the results obtained when no electrostatic field was applied, Splitless injection of a series of hydrocarbons up to C-28 in the electrospray inlet with an empty, tapered liner, using a cold needle, showed no measurable analyte discrimination. The relative standard deviation in terms of area count for the largest hydrocarbon (C-28) was < 1.5%, compared to similar to 30% for injections where no high voltage was applied.
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| 10. |
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| 11. |
- Felton, Adam, et al.
(författare)
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Replacing monocultures with mixed-species : Ecosystem service implications of two production forest alternatives in Sweden
- 2016
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Ingår i: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 45:Suppl. 2, s. 124-139
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Tidskriftsartikel (refereegranskat)abstract
- Whereas there is evidence that mixed-species approaches to production forestry in general can provide positive outcomes relative to monocultures, it is less clear to what extent multiple benefits can be derived from specific mixed-species alternatives. To provide such insights requires evaluations of an encompassing suite of ecosystem services, biodiversity, and forest management considerations provided by specific mixtures and monocultures within a region. Here, we conduct such an assessment in Sweden by contrasting even-aged Norway spruce (Picea abies)-dominated stands, with mixed-species stands of spruce and birch (Betula pendula or B. pubescens), or spruce and Scots pine (Pinus sylvestris). By synthesizing the available evidence, we identify positive outcomes from mixtures including increased biodiversity, water quality, esthetic and recreational values, as well as reduced stand vulnerability to pest and pathogen damage. However, some uncertainties and risks were projected to increase, highlighting the importance of conducting comprehensive interdisciplinary evaluations when assessing the pros and cons of mixtures.
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| 12. |
- Felton, Adam, et al.
(författare)
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Replacing monocultures with mixed-species stands : Ecosystem service implications of two production forest alternatives in Sweden
- 2016
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Ingår i: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 45, s. 124-139
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Tidskriftsartikel (refereegranskat)abstract
- Whereas there is evidence that mixed-species approaches to production forestry in general can provide positive outcomes relative to monocultures, it is less clear to what extent multiple benefits can be derived from specific mixed-species alternatives. To provide such insights requires evaluations of an encompassing suite of ecosystem services, biodiversity, and forest management considerations provided by specific mixtures and monocultures within a region. Here, we conduct such an assessment in Sweden by contrasting even-aged Norway spruce (Picea abies)-dominated stands, with mixed-species stands of spruce and birch (Betula pendula or B. pubescens), or spruce and Scots pine (Pinus sylvestris). By synthesizing the available evidence, we identify positive outcomes from mixtures including increased biodiversity, water quality, esthetic and recreational values, as well as reduced stand vulnerability to pest and pathogen damage. However, some uncertainties and risks were projected to increase, highlighting the importance of conducting comprehensive interdisciplinary evaluations when assessing the pros and cons of mixtures.
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| 13. |
- Hallquist, Mattias, 1969, et al.
(författare)
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Photochemical smog in China: scientific challenges and implications for air-quality policies
- 2016
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Ingår i: National Science Review. - : Oxford University Press (OUP). - 2095-5138 .- 2053-714X. ; 3:4, s. 401-403
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Tidskriftsartikel (refereegranskat)abstract
- In large areas of China severe air pollution events pose a significant threat to human health, ecosystems and climate. Current reduction of primary emissions will also affect secondary pollutants such as ozone (O3) and particulate matter (PM), but the magnitude of the effects is uncertain. Major scientific challenges are related to the formation of O3 and secondary particulate matter including Secondary Organic Aerosols (SOA). Large uncertainties also remain regarding the interactions of soot, SOA and O3 under the influence of different SO2, NOX and VOC concentrations. To improve the understanding of these secondary atmospheric interactions in China, scientific areas of central importance for photochemically induced air pollutants have been identified. In addition to the scientific challenges, results from research need to be synthesized across several disciplines and communicated to stakeholders affected by air pollution and to policy makers responsible for developing abatement strategies. Development of these science-policy interactions can benefit from experience gained under the UN ECE Convention on Long Range Transboundary Air Pollution (LRTAP)
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| 14. |
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| 15. |
- Kloskowski, Adam, et al.
(författare)
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Thick film traps with an irregular film : Preparation and evaluation
- 2004
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Ingår i: Journal of Chromatography A. - : Elsevier BV. - 0021-9673 .- 1873-3778. ; 1035:2, s. 159-165
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Tidskriftsartikel (refereegranskat)abstract
- A new method for preparation of sorbent-based ultra-thick film traps for concentration of trace volatile components from gaseous matrices is described. The procedure is based on blowing a prepolymer (polydimethylsiloxane) through a capillary tube, forming an irregular film of stationary phase. Subsequently, the prepolymer is immobilized in a few seconds by heating to 200 °C. Evaluation of the performance of the new traps showed that the loss of efficiency, compared to regular smooth film traps is only on the order of 20–30%. In terms of breakthrough volume, this loss in performance is rather insignificant. The technology is extremely simple and allows a rapid and cheap production of a large number of ultra-thick film traps, even in non-specialized laboratories. The method can be applied to any type of cross-linkable stationary phase, thereby expanding the scope of sorbent-based trapping and preconcentration concept. Many applications are anticipated in trace and ultra-trace analysis in a wide range of fields, such as environmental chemistry, polymers, food and process analysis.
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| 16. |
- Leong, Su-lin L., et al.
(författare)
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Genome and physiology of the ascomycete filamentous fungus Xeromyces bisporus, the most xerophilic organism isolated to date
- 2015
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Ingår i: Environmental Microbiology. - Hoboken, USA : Wiley-Blackwell. - 1462-2912 .- 1462-2920. ; 17:2, s. 496-513
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Tidskriftsartikel (refereegranskat)abstract
- Xeromyces bisporus can grow on sugary substrates down to 0.61, an extremely low water activity. Its genome size is approximately 22Mb. Gene clusters encoding for secondary metabolites were conspicuously absent; secondary metabolites were not detected experimentally. Thus, in its dry' but nutrient-rich environment, X.bisporus appears to have relinquished abilities for combative interactions. Elements to sense/signal osmotic stress, e.g. HogA pathway, were present in X.bisporus. However, transcriptomes at optimal (approximate to 0.89) versus low a(w) (0.68) revealed differential expression of only a few stress-related genes; among these, certain (not all) steps for glycerol synthesis were upregulated. Xeromyces bisporus increased glycerol production during hypo- and hyper-osmotic stress, and much of its wet weight comprised water and rinsable solutes; leaked solutes may form a protective slime. Xeromyces bisporus and other food-borne moulds increased membrane fatty acid saturation as water activity decreased. Such modifications did not appear to be transcriptionally regulated in X.bisporus; however, genes modulating sterols, phospholipids and the cell wall were differentially expressed. Xeromyces bisporus was previously proposed to be a chaophile', preferring solutes that disorder biomolecular structures. Both X.bisporus and the closely related xerophile, Xerochrysium xerophilum, with low membrane unsaturation indices, could represent a phylogenetic cluster of chaophiles'.
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| 17. |
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| 18. |
- Pettersson, Johan, et al.
(författare)
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Automated high-capacity sorption probe for extraction of organic compounds in aqueous samples followed by gas chromatographic analysis
- 2004
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Ingår i: Journal of Chromatography A. - : Elsevier BV. - 0021-9673 .- 1873-3778. ; 1033:2, s. 339-347
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Tidskriftsartikel (refereegranskat)abstract
- An automated high-capacity sorption device for GC analysis of ultra trace components has been developed. The scope of the presented technique was to combine the simplicity of solid-phase microextraction (SPME) with the high extraction efficiency of the stir bar sorptive extraction technology. Sorptive extractions of water samples were performed using polydimethylsiloxane (PDMS) rubber tubing (120 μl) mounted onto a glass rod. The sampling procedure was carried out by a robotic autoinjector. Since the setup is fully automated, unattended and precise time-controlled extraction of samples is possible and makes quantitation with non-equilibrium extractions feasible. The sorption probes are easy to exchange, which facilitates off-line/in-field sampling. The system was evaluated with a test mixture of 44 environmentally hazardous compounds. Detection limits were found to be in the sub-ppt region. The performance of the system was demonstrated with the analysis of polycyclic aromatic hydrocarbons in urban snow.
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| 19. |
- Pettersson, Johan, et al.
(författare)
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Method for analysis of polar volatile trace components in aqueous samples by gas chromatography
- 2005
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 77:10, s. 3365-3371
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Tidskriftsartikel (refereegranskat)abstract
- A new method has been developed for direct analysis of volatile polar trace compounds in aqueous samples by gas chromatography. Water samples are injected onto a short packed precolumn containing anhydrous lithium chloride. A capillary column is coupled in series with the prefractionation column for final separation of the analytes. The enrichment principle of the salt precolumn is reverse to the principles employed in conventional methods such as SPE or SPME in which a sorbent or adsorbent is utilized to trap or concentrate the analytes. Such methods are not efficient for highly polar compounds. In the LiCl pre-column concept, the water matrix is strongly retained on the hygroscopic salt, whereas polar as well as nonpolar volatile organic compounds show very low retention and are eluted ahead of the water. After transfer of the analytes to the capillary column, the retained bulk water is removed by backflushing the precolumn at elevated temperature. For direct injections of 120 μL of aqueous samples, the combined time for injection and preseparation is only 3.5 min. With this procedure, direct repetitive automated analyses of highly volatile polar compounds such as methanol or tetrahydrofuran can be performed, and a limit of quantification in the low parts-per-billion region utilizing a flame ionization detector is demonstrated.
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| 20. |
- Pettersson, Johan, 1971-
(författare)
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New concepts and techniques for quantification and trace analysis by gas chromatography
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the first part of this thesis, strategies for avoiding systematic errors when quantifying the main components in mixtures of solvents has been developed (paper I). It is shown that variations in density caused by variations in sample composition and/or volume contraction need to be taken into account. In this way, quantification can be improved. The second part (paper II-V) describes a number of new methods for the analysis of organic trace components present in gaseous or aqueous samples, after an overview of the most commonly applied sample enrichment techniques has been given. For the enrichment of volatile trace compounds from gaseous samples, the concept of open tubular trapping has been further developed. A simplified procedure for preparing ultra-thick film, sorptive open tubular traps (OTTs) is described (paper III). The traps are coated with an irregular film of PDMS, and it is shown that the performance in terms of breakthrough volume is only marginally affected by the use of such traps. In paper IV, it is shown both experimentally and with a theoretical model that the enrichment capacity of OTTs can be significantly increased by increasing the inner diameter of the traps. A fully automated procedure for high-capacity sorption enrichment of trace organic analytes present in water is also reported (paper II). Time-based non-equilibrium extractions are feasible, enabling fast extractions that still allow sub-ppt limits of detection. The high flexibility of the automated system makes it possible to sample from process streams or off-line sources. Finally, the development of a new 2-dimensional precolumn-backflush method for the analysis of polar volatile trace analytes in water is described (paper V). This concept is based on the action of a hygroscopic salt which has a strong affinity for water, in a precolumn. Organic trace compounds, such as volatile alcohols or ketones show little retention on the precolumn and are eluted ahead of the bulk amount of the water onto a capillary column for subsequent high resolution separation. The residual water is removed from the system by backflushing the precolumn. The procedure allows the direct injection of aqueous sample volumes of at least 100 µl, and the pre-fractionation is accomplished within only a few minutes. Quantification limits for selected polar trace components were in the low ppb-region.
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| 21. |
- Pettersson, Johan, et al.
(författare)
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Quantitative accuracy in the gas chromatographic analysis of solvent mixtures
- 2003
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Ingår i: Journal of Chromatography A. - 0021-9673 .- 1873-3778. ; 985:1-2, s. 21-27
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Tidskriftsartikel (refereegranskat)abstract
- Quantitative accuracy is of great importance in the analysis of bulk mixtures of solvents, particularly when the analysis is related to quality control of very large product volumes like in solvent recovery plants. Serious errors can be made if the effects of density differences between the pure solvents and volume contractions are not properly addressed. In earlier work, the use of an iterative process for correcting such errors has been suggested. However, in the case of volume contractions and mixtures of several solvents, this procedure is difficult to apply. In the present paper, we describe a simple procedure where calibration curves based on mass concentration are utilized. The densities of calibration mixtures of known compositions are determined with a density meter, in order to provide for correction factors caused by volume contractions. Model experiments with mixtures of water, ethanol, acetone and methanol showed a significant improvement in quantitative accuracy, when the suggested calibration strategy was applied.
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| 22. |
- Pettersson, Johan, et al.
(författare)
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The fossil alga Chaetocladus gracilis revisited : new material from the Silurian of Sweden
- 2020
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Ingår i: GFF. - : Informa UK Limited. - 1103-5897 .- 2000-0863. ; 142:4, s. 304-308
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Tidskriftsartikel (refereegranskat)abstract
- In 2006, a new species of non-calcified dasycladalean alga, Chaetocladus gracilis, from the upper Silurian of Skåne (Scania), southernmost Sweden, was erected. The original description was based on a single incomplete fossil recovered from the abandoned limestone quarry at Bjärsjölagård, a classic geologic locality in Scania. Here we present four additional and, importantly, more complete specimens from this same site and type stratum. This new material largely corroborates the general anatomical features of C. gracilis, but also adds some intricate details, most notably with regards to the external sheet-like phytoleim and organisation of the laterals. Elemental mapping confirmed an expected carbonaceous composition of the fossils, which are embedded in a calcareous mudstone. These additional fossils show that the originally described specimen was not a singular occurrence at this locality. Based on the state of preservation of our algal fossils, we note that the mudstone facies of the Ludlow Bjärsjölagård Limestone Member of the Klinta Formation (Öved-Ramsåsa Group), from which all C. gracilis have been recovered, share characteristics with deposits typically referred to as “algal-Lagerstätten”.
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| 23. |
- Pettersson, Johan, et al.
(författare)
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Ultra thick film open tubular traps with an increased inner diameter
- 2004
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Ingår i: Journal of Chromatography A. - : Elsevier BV. - 0021-9673 .- 1873-3778. ; 1047:1, s. 93-99
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, the concept of open tubular traps, coated with a very thick film of polydimethyldisiloxane for enrichment of trace volatile components has been further explored. From theoretical calculations as well as practical experiments it is demonstrated that it can be advantageous to increase the inner diameter of such traps. For a given sampling flow rate and phase ratio, the plate number of the traps is not dependent on the inner diameter, provided that the linear flow velocity remains sufficiently high to offset the effect of axial diffusion. It is shown that this is due to the basic fact that for a given sampling flow rate, the average linear flow velocity in the trap is inversely proportional to the square of the inner diameter of the trap. However, in contrast to chromatographic separations, the linear flow velocity is not important. Under conditions of a constant phase ratio, an increased inner diameter also increases the amount of sorbent in the trap, which is a key parameter for obtaining high breakthrough volumes. Open tubular traps with an expanded inner diameter have very low pressure drop characteristics, which provides the possibility to construct new, simplified sampling systems.
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| 24. |
- Vidner, Olle, 1990-, et al.
(författare)
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Multidisciplinary Design Optimization of a Mobile Miner Using the OpenMDAO Platform
- 2021
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Ingår i: Proceedings of the Design Society. - : Cambridge University Press. - 2732-527X. ; , s. 2207-2216
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Konferensbidrag (refereegranskat)abstract
- This paper proposes an optimization framework based on the OpenMDAO software library intended for engineer-to-order products and applies it to the conceptual design of a Mobile Miner. A Mobile Miner is a complex machine and a flexible alternative to Tunnel Boring Machines for small-scale tunneling and mining applications. The proposed framework is intended for use in early design and quotation stages with the objective to get fast estimates of important product characteristics, such as excavation rate and cutter lifetime. The ability to respond fast to customer requests is vital when offering customized products for specific applications and thereby to stay competitive on the global market. This is true for most engineer-to-order products and especially for mining equipment where each construction project is unique with different tunnel geometries and rock properties. The presented framework is applied to a specific use-case where the design of the miner's cutter wheel is in focus and a set of Pareto optimal designs are obtained. Furthermore, the framework extends the capabilities of OpenMDAO by including support for mixed-variable formulations and it supports an exploratory approach to design optimization.
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| 25. |
- Wiklund, Johan A., et al.
(författare)
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A comparative study of UVP and LDA techniques for pulp suspensions in pipe flow
- 2006
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Ingår i: AIChE Journal. - : Wiley. - 0001-1541 .- 1547-5905. ; 52:2, s. 484-495
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Tidskriftsartikel (refereegranskat)abstract
- For the first time, noninvasive measurements in pulp suspensions at consistencies ranging from 0.74%(w/w) up to 7.8%(w/w) have been performed simultaneously using ultrasound velocity profiling (UVP) and laser doppler anemometry (LDA) in an experimental pipe flow loop. Results show that both techniques can be used to determine the plug flow velocity with good agreement in much more concentrated pulp suspensions than what has been reported so far in the literature. Instantaneous velocity profiles have been obtained noninvasively in pipe flow using the UVP technique, and it is shown that combined with simultaneous pressure drop measurements, the UVP technique can be used to determine the yield stress in-line. Results further show that LDA works, with limited penetration depth of up to several millimeters, even in strongly opaque systems, such as in 7.8%(w/w) pulp. Deviating results were however obtained in the near wall region and more work is needed.
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| 26. |
- Yucel, Yasemin Duygu, et al.
(författare)
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Powder-impregnated carbon fibers with lithium iron phosphate as positive electrodes in structural batteries
- 2023
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Ingår i: Composites Science And Technology. - : Elsevier Ltd. - 0266-3538 .- 1879-1050. ; 241
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Tidskriftsartikel (refereegranskat)abstract
- A structural battery is a multifunctional battery that can carry a load while storing energy. Structural batteries have been a cutting-edge research focus in the last decade and are mainly based on polyacrylonitrile (PAN)-carbon fibers (CFs). In this work, positive electrodes based on PAN-carbon fibers were manufactured with powder impregnation (siphon impregnation) technique using a water-based slurry containing lithium iron phosphate (LFP) as the active electrode material and the water-soluble binder polyethylene glycol (PEG). Different coating compositions, electrode-drying temperatures, and coating parameters were investigated to optimize the coating uniformity and the electrochemical performances. Scanning electron microscopy results showed that the electrode materials coat the CFs uniformly, conformably, and individually. Electrochemical characterization of pouch cells shows that the electrodes containing 6 wt% PEG dried at 140 °C have the best battery performance, delivering a first discharge capacity of 151 mAh g−1 and capacity retention higher than 80% after 100 cycles. Moreover, excellent capacity reversibility was achieved when the electrodes were cycled at multiple C-rates attesting to their stability. The results demonstrate that CFs perform excellently as current collectors in positive electrodes.
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| 27. |
- Åkesson, Karolina, et al.
(författare)
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Kynurenine pathway is altered in patients with SLE and associated with severe fatigue
- 2018
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Ingår i: Lupus Science and Medicine. - : BMJ Publishing Group Ltd. - 2053-8790. ; 5:1
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Fatigue has been reported as the most disturbing symptom in a majority of patients with SLE. Depression is common and often severe. Together these symptoms cause significant morbidity and affect patients with otherwise relatively mild disease. Tryptophan and its metabolites in the kynurenine pathway are known to be important in several psychiatric conditions, for example, depression, which are often also associated with fatigue. We therefore investigated the kynurenine pathway in patients with SLE and controls.Methods: In a cross-sectional design plasma samples from 132 well-characterised patients with SLE and 30 age-matched and gender-matched population-based controls were analysed by liquid chromatography tandem mass spectrometry to measure the levels of tryptophan and its metabolites kynurenine and quinolinic acid. Fatigue was measured with Fatigue Severity Scale and depression with Hospital Anxiety and Depression Scale. SLE disease activity was assessed with Systemic Lupus Erythematosus Disease Activity Index (SLEDAI).Results: The kynurenine/tryptophan ratio, as a measure of indoleamine 2,3-dioxygenase (IDO) activity, was increased in patients with SLE. Patients with active disease (SLEDAI >= 6) showed lower tryptophan levels compared with controls (54 mu M, SD=19 vs 62 mu M, SD=14, p=0.03), although patients with SLE overall did not differ compared with controls. Patients with SLE had higher levels of tryptophan metabolites kynurenine (966 nM, SD=530) and quinolinic acid (546 nM, SD=480) compared with controls (kynurenine: 712 nM, SD=230, p=0.0001; quinolinic acid: 380 nM, SD=150, p=0.001). Kynurenine, quinolinic acid and the kynurenine/tryptophan ratio correlated weakly with severe fatigue (r(s)=0.34, r(s)=0.28 and r(s)=0.24, respectively) but not with depression.Conclusions: Metabolites in the kynurenine pathway are altered in patients with SLE compared with controls. Interestingly, fatigue correlated weakly with measures of enhanced tryptophan metabolism, while depression did not. Drugs targeting enzymes in the kynurenine pathway, for example, IDO inhibitors or niacin (B12) supplementation, which suppresses IDO activity, merit further investigation as treatments in SLE.
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| 28. |
- Ablikim, M., et al.
(författare)
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Measurement of e plus e-? : ??0 cross sections at center-of-mass energies between 3.508 and 4.600 GeV
- 2023
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Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 107:7
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Tidskriftsartikel (refereegranskat)abstract
- We present a measurement of the dressed cross sections for e+e- -> phi eta at different center-of-mass energies between 3.508 and 4.600 GeV based on 15.1 fb-1 of e+e- annihilation data collected with the BESIII detector operating at the BEPCII collider. In addition, a search for the decay Y(4230) -> phi eta is performed. No clear signal is observed and the corresponding upper limit is provided.
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| 29. |
- Adielsson, Anna, et al.
(författare)
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Outcome prediction for patients assessed by the medical emergency team : a retrospective cohort study
- 2022
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Ingår i: BMC Emergency Medicine. - : Springer Science and Business Media LLC. - 1471-227X. ; 22:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Medical emergency teams (METs) have been implemented to reduce hospital mortality by the early recognition and treatment of potentially life-threatening conditions. The objective of this study was to establish a clinically useful association between clinical variables and mortality risk, among patients assessed by the MET, and further to design an easy-to-use risk score for the prediction of death within 30 days.Methods: Observational retrospective register study in a tertiary university hospital in Sweden, comprising 2,601 patients, assessed by the MET from 2010 to 2015. Patient registry data at the time of MET assessment was analysed from an epidemiological perspective, using univariable and multivariable analyses with death within 30 days as the outcome variable. Predictors of outcome were defined from age, gender, type of ward for admittance, previous medical history, acute medical condition, vital parameters and laboratory biomarkers. Identified factors independently associated with mortality were then used to develop a prognostic risk score for mortality.Results: The overall 30-day mortality was high (29.0%). We identified thirteen factors independently associated with 30-day mortality concerning; age, type of ward for admittance, vital parameters, laboratory biomarkers, previous medical history and acute medical condition. A MET risk score for mortality based on the impact of these individual thirteen factors in the model yielded a median (range) AUC of 0.780 (0.774-0.785) with good calibration. When corrected for optimism by internal validation, the score yielded a median (range) AUC of 0.768 (0.762-0.773).Conclusions: Among clinical variables available at the time of MET assessment, thirteen factors were found to be independently associated with 30-day mortality. By applying a simple risk scoring system based on these individual factors, patients at higher risk of dying within 30 days after the MET assessment may be identified and treated earlier in the process.
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| 30. |
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| 31. |
- Aguilera, Guillermo, et al.
(författare)
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Intensive management reduces butterfly diversity over time in urban green spaces
- 2019
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Ingår i: Urban Ecosystems. - : Springer Science and Business Media LLC. - 1083-8155 .- 1573-1642. ; 22:2, s. 335-344
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Tidskriftsartikel (refereegranskat)abstract
- Loss and fragmentation of semi-natural grasslands have had negative consequences for grassland biodiversity, such as butterflies. Urban parks and other urban green spaces have so far largely been overlooked as suitable butterfly habitats, although they could potentially sustain diverse butterfly populations over time. We analysed the temporal change in butterfly species assemblages in urban green spaces in the city of Malmö, Southern Sweden. We studied changes in species richness and abundance of butterflies between 2006 and 2015 in 20 public urban green spaces, characterized by different management regimes. We sampled butterflies in traditional parks with intense grass cutting regimes, in semi-natural grasslands mowed only a few times per year, and in un-managed or irregularly managed ruderal sites. We found a slight increase in the total number of butterfly species in the study area, but a general decline in local species numbers in urban green spaces. Traditional urban parks had the greatest loss of species over time, and altogether the lowest number of species. In contrast, semi-natural parks and ruderal sites had higher numbers of butterfly species and also lost fewer species over time. Our study shows that intensive management strategies in urban green spaces have a negative impact on butterfly assemblages over time. We suggest that less intensive management strategies can be used to create high-quality areas for flower-visiting insects in urban green spaces, possibly in combination with planting larval host plant species, depending on the park type and design.
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| 32. |
- Ahlin, Jane, et al.
(författare)
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Strategies to develop and strengthen human factors and ergonomics knowledge among stakeholders in Sweden
- 2015
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Ingår i: Proceedings 19th Triennial Congress of the IEA, Melbourne 9-14 August 2015. - Melbourne : International Ergonomics Association.
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Konferensbidrag (refereegranskat)abstract
- Knowledge and application of human factors and ergonomics (HFE) has significant potential as auseful tool and solution provider in the development, design and implementation of safe, efficient and sustainable artefacts and systems. Yet, it seems that this HFE knowledge is not utilised to its full potential. In a world of competing financial and commercial priorities, HFE specialists have apparently not succeeded in selling the systems approach as a tool towards improved overall systems performance and human well-being.The present paper describes the strategic and practical workperformed by the Swedish Ergonomics and Human Factors Society (EHSS) to strengthen the quality of human factors and ergonomics knowledge and practice among various stakeholders in Sweden. EHSS view human factors and ergonomics as a systems and design oriented discipline that extends across all aspects of human activity. Beyond the traditional domains of specialization within the discipline, the physical, cognitive and organisational ergonomics, EHSS has identified three focus areas; visual ergonomics, voice ergonomics and ergonomics design for all.Practitioner Summary: This paper presents the strategic and practical work performed by the Swedish Ergonomics and Human Factors Society (EHSS) in order to strengthen the quality of human factors and ergonomics knowledge and practice in Sweden. EHSS has identified three focus areas for its strategic work: visual ergonomics, voice ergonomics and ergonomics design for all.
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| 33. |
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| 34. |
- Ahlström, Johan, 1990, et al.
(författare)
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Economic potential for substitution of fossil fuels with liquefied biomethane in Swedish iron and steel industry – Synergy and competition with other sectors
- 2020
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Ingår i: Energy Conversion and Management. - : Elsevier Ltd. - 0196-8904 .- 1879-2227. ; 209
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Tidskriftsartikel (refereegranskat)abstract
- In Sweden, the iron and steel industry (ISI) is a major source of greenhouse gas (GHG) emissions. Most of the emissions result from the use of fossil reducing agents. Nevertheless, the use of fossil fuels for other purposes must also be eliminated in order to reach the Swedish emissions reduction targets. In this study, we investigate the possibility to replace fossil gaseous and liquid fuels used for heating in the ISI, with liquefied biomethane (LBG) produced through gasification of forest residues. We hypothesize that such utilization of fuels in the Swedish ISI is insufficient to independently drive the development of large-scale LBG production, and that other sectors demanding LBG, e.g., for transportation, can be expected to influence the economic potential for the ISI to switch to LBG. The paper investigates how demand for LBG from other sectors can contribute to, or prevent, a phase-out of fossil fuels used for heating purposes in the ISI under different future energy market scenarios, with additional analysis of the impact of a CO2 emissions charge. A geographically explicit cost-minimizing biofuel production localization model is combined with heat integration and energy market scenario analysis. The results show that from a set of possible future energy market scenarios, none yielded more than a 9% replacement of fossil fuels used for heating purposes in the ISI, and only when there was also a demand for LBG from other sectors. The scenarios corresponding to a more ambitious GHG mitigation policy did not achieve higher adoption of LBG, due to corresponding higher biomass prices. A CO2 charge exceeding 200 EUR/tonCO2 would be required to achieve a full phase-out of fossil fuels used for heating purposes in the ISI. We conclude that with the current policy situation, substitution of fossil fuels by LBG will not be economically feasible for the Swedish ISI.
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| 35. |
- Ahlström, Johan, et al.
(författare)
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Value chains for integrated production of liquefied bio-SNG at sawmill sites – Techno-economic and carbon footprint evaluation
- 2017
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 206, s. 1590-1608
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Tidskriftsartikel (refereegranskat)abstract
- Industry's increasing demand for liquefied natural gas could be met in the future by liquefied methane produced from biomass feedstock (LBG - liquefied biogas). This study presents results from an investigation of value chains for integrated production of LBG at a generic sawmill site, based on gasification of sawmill waste streams and forest residues. The objective was to investigate the cost for, as well as the carbon footprint reduction associated with, production and use of LBG as a fuel. Five different LBG plant sizes were investigated in combination with three different sawmill sizes. The resulting cases differ regarding biomass feedstock composition, biomass transportation distances, LBG plant sizes, how efficiently the excess heat from the LBG plant is used, and LBG distribution distances. Pinch technology was used to quantify the heat integration opportunities and to design the process steam network. The results show that efficient use of energy within the integrated process has the largest impact on the performance of the value chain in terms of carbon footprint. The fuel production cost are mainly determined by the investment cost of the plant, as well as feedstock transportation costs, which mainly affects larger plants. Production costs are shown to range from 68 to 156 EUR/MW hfuel and the carbon footprint ranges from 175 to 250 kg GHG-eq/MW hnet biomass assuming that the product is used to substitute fossil LNG fuel. The results indicate that process integration of an indirect biomass gasifier for LBG production is an effective way for a sawmill to utilize its by-products. Integration of this type of biorefinery can be done in such a way that the plant can still cover its heating needs whilst expanding its product portfolio in a competitive way, both from a carbon footprint and cost perspective. The results also indicate that the gains associated with efficient heat integration are important to achieve an efficient value chain.
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| 36. |
- Alatalo, Mikael C D, 1959, et al.
(författare)
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Performance of the position control of a permanent magnet sensorless drive
- 2012
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Ingår i: 2nd International Electric Drives Production Conference, EDPC 2012, Nuremberg,15 through18 October 2012. - 9781467330060 ; :Article number 6425100, s. 1-5
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Konferensbidrag (refereegranskat)abstract
- A sensor less position control of a permanent magnet motor has been implemented. The permanent magnet motor is made with interior magnets and concentrated windings. The 4-pole machine can produce 0.4 Nm of continuous torque and have a top speed of 2000 rpm. The peak torque is 0.8 Nm and the system DC-link voltage is 24 V. Sensorless control is utilised with signal injection during low speed operation and at higher speed the induced emf is used for tracking the rotor angle. The estimated rotor angle is used for positioning an ordinary FOC, (Field Oriented Control). The performance of the system is simulated, including FEM-calculated values of saturated flux in d-and q-axes. Cascaded regulators for the speed and the position make it possible to control the mechanical position of the machine. Tests on the real application show a position error of 30 electrical degrees. In this case it corresponds to +/-15 degrees on the mechanical shaft. © 2012 IEEE.
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| 37. |
- Allard, Anna, et al.
(författare)
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Småbiotopsuppföljning i NILS år 2008
- 2009
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Denna rapport presenterar resultat för mängden av småbiotoper vid åkermark i det svenska landskapet. Analyserna görs på uppdrag av Jordbruksverket, som underlag för bl.a. utvärderingen av miljökvalitetsmålet Ett rikt odlingslandskap. Särskilda rutiner har tagits fram för att aggregera olika variabler för att välja ut de småbiotoper som uppfyller de krav som Jordbruksverket har ställt upp, ur den befintliga databasen. Urvalet av småbiotoper är anpassat för att överensstämma med det urval av objekt som ingår i det s.k. KULT-stödet (miljöersättning till lantbrukare för skötsel av värdefulla natur- och kulturmiljöer) inom Jordbruksverkets Landsbygdsprogram. Arbetet har utförts vid institutionen för skoglig resurshushållning, Sveriges lantbruks-universitet, Umeå. Resultaten baseras på data från flygbildsinventeringen inom det nationella miljöövervakningsprogrammet NILS (Nationell Inventering av Landskapet i Sverige) vilket följer tillstånd och förändringar i det svenska landskapet och hur dessa påverkar förutsättningarna för den biologiska mångfalden. NILS finansieras av Naturvårdsverket, och ingår där i programområde Landskap. Ett viktigt syfte med programmet är att följa upp de nationella miljökvalitetsmålen för olika naturtyper och fungera som underlag för att se om genomförda policybeslut och miljövårdsåtgärder leder till önskade förbättringar
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| 38. |
- Andersson, Martin, et al.
(författare)
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Thin film metal sensors in fusion bonded glass chips for high-pressure microfluidics
- 2017
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Ingår i: Journal of Micromechanics and Microengineering. - : IOP Publishing. - 0960-1317 .- 1361-6439. ; 27:1
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Tidskriftsartikel (refereegranskat)abstract
- High-pressure microfluidics offers fast analyses of thermodynamic parameters for compressed process solvents. However, microfluidic platforms handling highly compressible supercritical CO2 are difficult to control, and on-chip sensing would offer added control of the devices. Therefore, there is a need to integrate sensors into highly pressure tolerant glass chips. In this paper, thin film Pt sensors were embedded in shallow etched trenches in a glass wafer that was bonded with another glass wafer having microfluidic channels. The devices having sensors integrated into the flow channels sustained pressures up to 220 bar, typical for the operation of supercritical CO2. No leakage from the devices could be found. Integrated temperature sensors were capable of measuring local decompression cooling effects and integrated calorimetric sensors measured flow velocities over the range 0.5-13.8 mm/s. By this, a better control of high-pressure microfluidic platforms has been achieved.
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| 39. |
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| 40. |
- Anheden, Marie, et al.
(författare)
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Value chains for production of Renewable Transportation Fuels Using Intermediates
- 2016
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- An increased share of renewable transportation fuels requires utilisation of new low-cost sources of bio-based raw materials other than what is currently used in the pulp and paper industry and for power and district heat generation in the bioenergy sector. Currently, proposed raw material includes forest residues (branches and tops), stumps, waste round wood and different by-products from pulp and pa-per industry and sawmills. Of these, forest residues and stumps have, by far, the largest potential for increased utilisation. However, these types of raw materials are often voluminous and heterogeneous and are difficult to handle in existing refineries for production of transportation fuels. The cost of transporting this type of raw material over large distances in order to supply a larger plant is often said to be high. This report includes an analysis of the possible advantages and disadvantages of transform-ing forest-based biomass to an intermediate product with a higher energy density that is more homo-geneous and easier to handle during transport and during final conversion to transportation fuel.Two value chains are investigated as case studies a) bio-SNG production using forest residues, bark and sawdust as raw material and b) bio-oil production from forest residues, lignin in black liquor and tall oil, which can be upgraded to transportation fuels at a refinery. In the study we have assumed that the conversion of the original biomass to an intermediate product mainly takes place at a pulp mill. The intermediate conversion technologies included for value chain a) are drying and pelletizing and for value chain b) pyrolysis and distillation. The final conversion to end product bio-SNG takes place in connection to a district heating system, and the final deoxygenation and upgrading of bio-oil to hydrodeoxygenated (HDO) oil takes place at an oil refinery. The value chains with intermediates are compared with value chains without intermediates where the entire conversion process to final product is located in connection to a district heating system in value chain a) and at a stand-alone plant near to a refinery in value chain b). The value chains are studied from a well-to-gate perspective, from extrac-tion of the forest biomass to produced bio-SNG/HDO bio-oil. A direct comparison between value chains for bio-SNG and bio-oil production should be avoided. They are based on different reference data that are not synchronized. A direct comparison between the chains should in addition be done in a well-to-wheel perspective.The results show that the initial hypothesis that local production of a more energy dense intermediate would reduce transportation costs could not be verified. The reason is primarily the introduction of a second transport step to transport the intermediate to the final conversion site in addition to the transport of the raw material. The transport costs are associated with relatively high fixed cost espe-cially for ship and train transport, so the introduction of a second relatively high fixed transport cost of the intermediate has a dominating effect. Further, it can be concluded that the transport cost make up a relatively small share of the total production cost of the final product, in the order of 10%, and in a few cases up to 20%. There is therefore a relatively small difference in total specific production cost for the final product between value chains with and without intermediates considering the level of uncer-tainty in the input data and the assumptions behind the scenarios studied.Summarizing, the results indicate that the production costs are highly sensitive to the economies of scale, oxygen content in the bio-crude oil and raw material costs (forest residues price or electricity price in the case where lignin is used as raw material). Transportation costs have, comparatively, a little effect in the total production cost.
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| 41. |
- Anter, Karin Fridell, et al.
(författare)
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SYN-TES INTERDISCIPLINARY RESEARCH ON COLOUR AND LIGHT
- 2012
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Ingår i: Proceedings for Interim Meeting of the International Colour Association (AIC); AIC 2012 “In Color We Live: Color and Environment”, 22 – 25 September 2012, Taipei, Taiwan. - : The International Colour Association. ; , s. 80-83, s. 80-83
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Konferensbidrag (refereegranskat)abstract
- Colour and light have largely been considered as belonging to two different fields of knowledge, having disparate theoretical, terminological and methodological traditions. This creates a ground for misunderstandings and obstructs a fruitful interdisciplinary and interprofessional collaboration. A survey over international research literature from 2006 -2011 shows that there has been only little research on the spatial interaction between colour and light, but that the interest for this area has recently increased. The interdisciplinary Nordic research project SYN-TES: Human colour and light synthesis. Towards a coherent field of knowledge was carried out during 2010-11. Colour and light experts from Nordic universities and companies investigated different aspects of the spatial interaction between colour and light and its importance for human beings. This paper deals with the general learnings from the process. Specific results are presented in other papers at this conference.
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| 42. |
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| 43. |
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| 44. |
- Bahar, Bahram, et al.
(författare)
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Developing A-GPS as a Student Project
- 2006
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Rapport (populärvet., debatt m.m.)abstract
- The project consists of ten fourth-year computer science students at Uppsala University developing an A-GPS (Assisted-GPS) system. During the fall term of 2005 the students have developed a module for GPS-calculations in a GSM-network and an application that demonstrates a possible way of using the calculations module. This paper describes the design, the development process and the results of the project.
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| 45. |
- Banerjee, Indradumna, et al.
(författare)
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Slipdisc : A versatile sample preparation platform for point of care diagnostics
- 2017
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Ingår i: RSC Advances. - : Royal Society of Chemistry. - 2046-2069. ; 7:56, s. 35048-35054
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Tidskriftsartikel (refereegranskat)abstract
- We report a microfluidic sample preparation platform called "Slipdisc" based on slipchip technology. Slipdisc is a rotational slipchip that uses a unique hand-wound clockwork mechanism for precise movement of specially fabricated polycarbonate discs. In operation, the microchannels and microchambers carved on the closely aligned microfluidic discs convert from continuous filled paths to defined compartments using the slip movement. The clockwork mechanism introduced here is characterised by a food dye experiment and a conventional HRP TMB reaction before measuring lactate dehydrogenase (LDH) enzyme levels, which is a crucial biomarker for neonatal diagnostics. The colorimetry based detection of LDH was performed with an unmodified camera and an image analysis procedure based on normalising images and observing changes in red channel intensity. The analysis showed a close to unity coefficient of determination (R2 = 0.96) in detecting the LDH concentration when compared with a standard Chemical Analyser, demonstrating the excellent performance of the slipdisc platform with colorimetric detection. The versatile point of care sample preparation platform should ideally be suited for a multitude of applications at resource-limited settings.
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| 46. |
- Bargholtz, Chr., et al.
(författare)
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The WASA detector facility at CELSIUS
- 2008
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 594:3, s. 339-350
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Tidskriftsartikel (refereegranskat)abstract
- The WASA 4 pi multidetector system, aimed at investigating light meson production in light ion collisions and eta meson rare decays at the CELSIUS storage ring in Uppsala is presented. A unique feature of the system is the use of hydrogen pellets as internal targets for the first time. A detailed description of the design, together with the anticipated and achieved performance parameters are given. (C) 2008 Elsevier B.V. All rights reserved.
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| 47. |
- Behrmann Gerd,, et al.
(författare)
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UPPAAL Implementation Secrets
- 2002
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Ingår i: International Symposium on Formal Techniques in Real-Time and Fault Tolerant Systems. ; , s. 3-
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Konferensbidrag (refereegranskat)
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| 48. |
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| 49. |
- Berglund, Pierre, et al.
(författare)
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Dynamic Characteristics of Exhaust System Hangers
- 1999
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Comfort in automobiles is greatly affected by vibrations and noise transmitted to the chassis from the engine. This is a study of the dynamic characteristics of exhaust system hangers, which is an important transfer path for vibrations. Theoretical and experimental modal analysis is used to suggest design parameters that increase the natural frequencies to above 450 Hz for two hanger types.
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| 50. |
- Bergvall, Ida, 1975-
(författare)
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Bokstavligt, bildligt och symboliskt i skolans matematik : – en studie om ämnesspråk i TIMSS
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The overall aim of this thesis is to deepen the understanding of mathematical subject language regarding three semiotic resources, written language, images and mathematical symbols. The theses also investigates high- and low-performingstudents encounter with mathematical subject language.Based on previous research on language and from a theoretical foundation based on systemic functional linguistics (SFL) and social semiotics, four meaning dimensions – packing, precision, personification and presentation – were identified as central in academic language in general and in mathematical subject language. A didactically based reception theoretical perspective has been used for an analysis of high and low achieving students' encounter with the mathematical subject language.The thesis comprises three studies each examining the mathematical subject language in TIMSS 2011 from various angles. The analyzes were conducted on four content areas algebra, statistics, geometry and arithmetic in the Swedish version of the international study Trends in International Mathematics and Science Study 2011 (TIMSS).In a summary, the results showed that the mathematical subject language was used in different ways in the four content areas in TIMSS where colloquial and subject-specific forms of languages had different roles and were expressed in varying degrees by the written language, images and mathematical symbols. Thus each content area was expressed by its own register which means that is not sufficient to talk about mathematical subject language as one single language.The result shows that two forms of language, subject specific and everyday language were used parallel in the TIMSS material. The subject specific forms were most salient in algebra and geometry and the more everyday forms of language were more common in statistics and arithmetic.The results from the correlation analyses indicated that fewer students managed the encounter with tasks in algebra and geometry when they were expressed by subject specific language. In contrast, the results indicated that students were able handle the encounter with the more colloquial expressions of the content areas statistics and arithmetic.
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