| 1. |
- Brink Pinto, Andrés, et al.
(författare)
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Inledning
- 2022
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Ingår i: Kritiska blickar från marginalen : Reflektioner i spåren av Jens Rydström - Reflektioner i spåren av Jens Rydström. - : Department of Gender Studies, Lund University. - 9789180392938 - 9789180392945 ; , s. 11-22
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 2. |
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| 3. |
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| 5. |
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| 6. |
- Alfredsson, Eva C., et al.
(författare)
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Industrial climate mitigation strategies and the remaining fair carbon budget – The case of Sweden
- 2024
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Ingår i: Next Sustainability. - 2949-8236. ; 3, s. 100031-100031
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Tidskriftsartikel (refereegranskat)abstract
- This article explores the climate mitigation strategies of the 15 industries with the largest carbon dioxide emissions in Sweden. Starting from two carbon budget alternatives, we analyse the mitigation projections of the companies in relation to what can be considered their fair share of the remaining carbon budget for Sweden.We furthermore determine the uncertainties associated with the strategies. The results suggest that if the communicated mitigation plans are implemented as planned, the companies overdraft our main, 1.5-degree, budget option but stay within the alternative 1.7-degree budget. The analysis shows, however, that the timing and efficiency of emission reductions are crucial.Already small delays or lower efficiency in implementation, result in evident overdrafts of also the alternative budget. There are also substantial political and technical risks which can prevent timely mitigations. The article makes a novel contribution by analyzing industries’ mitigation strategies relative to their share of the remaining carbon budget.The article demonstrates the importance of transparent industrial climate mitigation strategies and in particular the need for policymakers to set incentive structures to promote strategy implementation.
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| 7. |
- Alfredsson, Eva, 1963-, et al.
(författare)
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Investeringar för en rättvis klimatomställning
- 2023
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Annan publikation (populärvet., debatt m.m.)abstract
- Inom forskningsprogrammet FAIRTRANS har en workshop hållits om investeringars roll i klimatomställningen. Syftet var att lyfta fram olika gruppers behov av investeringar för en rättvis fossilfri framtid inom ramen för en svensk koldioxidbudget.
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| 8. |
- Alfredsson, Eva, 1963-, et al.
(författare)
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Investeringars betydelse för klimatomställningen
- 2023
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Rapport (populärvet., debatt m.m.)abstract
- Syftet med detta kunskapsunderlag är att förbereda för deltagande och dialog inför FAIRTRANS Workshop 2. Fokus för diskussionen är vilka investeringar som bör prioriteras för att Sverige ska nå en rättvis koldioxidbudget.
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| 9. |
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| 10. |
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| 11. |
- Bjoreland, Anders, et al.
(författare)
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Liquid ionization chamber calibrated gel dosimetry in conformal stereotactic radiotherapy of brain lesions
- 2008
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Ingår i: Acta Oncologica. - : Informa UK Limited. - 1651-226X .- 0284-186X. ; 47:6, s. 1099-1109
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Tidskriftsartikel (refereegranskat)abstract
- Hypofractionated conformal stereotactic radiotherapy (HCSRT) is an established method of treating brain lesions such as arteriovenous malformations (AVMs) and brain metastases. The aim of this study was to investigate the reliability of treatment plans in the terms of dose distribution and absorbed dose for HCSRT. Methods and materials. Treatment plans for three different clinical intracerebral targets, AVMs, were transferred to a CT study of a spherical water filled phantom simulating the human head and recalculated for the phantom geometry using a standard treatment planning system utilizing a pencil beam algorithm for dose calculation. The calculated absorbed dose, relative three dimensional (3D) dose distribution and dose conformity were investigated using gel dosimetry normalized to liquid ionization chamber (LIC) measurements. Results. The measured absorbed dose to the dose reference point was found to be within 2% of the calculated dose for all three targets. The measured dose distribution was found to be within 3% and 2 mm of the calculated dose for more than 93% of all points in the target volume for all three targets. Conclusions. The results show that the investigated standard treatment planning system can correctly predict the absorbed dose and dose distribution in different types of intracerebral targets and that the treatment can be delivered according to the plan.
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| 12. |
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| 13. |
- Blomquist, M, et al.
(författare)
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Multileaf collimation of electrons-clinical effects on electron energy modulation and mixed beam therapy depending on treatment head design
- 2002
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Ingår i: Physics in Medicine and Biology. - 0031-9155 .- 1361-6560. ; 47:7, s. 1013-1024
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Tidskriftsartikel (refereegranskat)abstract
- The aim Of this Study was to explore the possibilities of using multileaf-collimated electron beams for advanced radiation therapy with conventional scattering foil flattened beams. Monte Carlo simulations were performed with the aim to improve electron beam characteristics and enable isocentric multileaf collimation. The scattering foil positions, monitor chamber thickness, the MLC location and the amount of He in the treatment head were optimized for three common commercial accelerators. The performance of the three optimized treatment head designs was compared for different SSDs in air. at treatment depth in water and for some clinical cases. The effects of electron/photon beam matching including generalized random and static errors using Gaussian one-dimensional (1D) error distributions, and also electron energy modulation, were studied at treatment depth in beater, The modification of the treatment heads improved the electron beam characteristics and enabled the use of multileaf collimation in isocentric delivery of both electron and photon beams in a mixed beam IMRT procedure.
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| 14. |
- Broberg, Martin, et al.
(författare)
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Comparative genomics highlights the importance of drug efflux transporters during evolution of mycoparasitism in Clonostachys subgenus Bionectria (Fungi, Ascomycota, Hypocreales)
- 2021
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Ingår i: Evolutionary applications. - : Wiley. - 1752-4571. ; 14, s. 476-497
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Tidskriftsartikel (refereegranskat)abstract
- Various strains of the mycoparasitic fungal speciesClonostachys roseaare used commercially as biological control agents for the control of fungal plant diseases in agricultural crop production. Further improvements of the use and efficacy ofC. roseain biocontrol require a mechanistic understanding of the factors that determines the outcome of the interaction betweenC. roseaand plant pathogenic fungi. Here, we determined the genome sequences of 11Clonostachysstrains, representing five species inClonostachyssubgenusBionectria, and performed a comparative genomic analysis with the aim to identify gene families evolving under selection for gene gains or losses. Several gene families predicted to encode proteins involved in biosynthesis of secondary metabolites, including polyketide synthases, nonribosomal peptide syntethases and cytochrome P450s, evolved under selection for gene gains (p <= .05) in theBionectriasubgenus lineage. This was accompanied with gene copy number increases (p <= .05) in ATP-binding cassette (ABC) transporters and major facilitator superfamily (MFS) transporters predicted to contribute to drug efflux. MostClonostachysspecies were also characterized by high numbers of auxiliary activity (AA) family 9 lytic polysaccharide monooxygenases, AA3 glucose-methanol-choline oxidoreductases and additional carbohydrate-active enzyme gene families with putative activity (or binding) towards xylan and rhamnose/pectin substrates. Particular features of theC. roseagenome included expansions (p <= .05) of the ABC-B4 multidrug resistance transporters, the ABC-C5 multidrug resistance-related transporters and the 2.A.1.3 drug:H + antiporter-2 MFS drug resistance transporters. The ABC-G1 pleiotropic drug resistance transporter geneabcG6inC. roseawas induced (p <= .009) by exposure to the antifungalFusariummycotoxin zearalenone (1121-fold) and various fungicides. Deletion ofabcG6resulted in mutants with reduced (p < .001) growth rates on media containing the fungicides boscalid, fenhexamid and iprodione. Our results emphasize the role of biosynthesis of, and protection against, secondary metabolites inClonostachyssubgenusBionectria.
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| 15. |
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| 16. |
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| 17. |
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| 18. |
- Fhager, Andreas, 1976, et al.
(författare)
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Microwave Technology in Medical Diagnostics and Treatment
- 2015
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Ingår i: 2015 Ieee Mtt-S International Microwave Workshop Series on Rf and Wireless Technologies for Biomedical and Healthcare Applications. - New York : Ieee. - 9781479985432 ; , s. 133-134
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- There is a great need for novel diagnostics and treatment tools in today's healthcare. In this paper we describe our development and progress in novel microwave based diagnostics and treatment applications. The target applications are stroke diagnostics, breast cancer detection and microwave hyperthermia.
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| 19. |
- Forsberg, Pontus, et al.
(författare)
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Diamond grating waveplates
- 2016
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Ingår i: Optical Materials Express. - : Optical Society of America. - 2159-3930 .- 2159-3930. ; 6:6, s. 2024-2030
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Tidskriftsartikel (refereegranskat)abstract
- Two designs of diamond quarter-wave plates for CO2 lasers, based on the birefringence of sub-wavelength gratings, were manufactured and tested. In one design the grating was etched on the surface of a 300 mu m thick polycrystalline diamond substrate. The other consisted of a diamond grating hanging freely in air, suspended at the edges from a silicon frame. The free-hanging design, while more fragile, had several advantages both in terms of fabrication and performance such as a larger grating period, higher transmission, and no need for an antireflective treatment of the backside.
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| 20. |
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| 21. |
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| 22. |
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| 23. |
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| 24. |
- Gilljam, Mikael, 1957, et al.
(författare)
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Representatives' Attitudes Toward Citizen Protests in Sweden: The Impact of Ideology, Parliamentary Position and Experiences
- 2012
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Ingår i: Legislative Studies Quarterly. - : Wiley. - 0362-9805. ; 37:2, s. 251-268
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Tidskriftsartikel (refereegranskat)abstract
- What affects political representatives' attitudes toward citizen protests? We test the impact of political representatives' left-right ideology, parliamentary position, and earlier experience of citizen protests. Using data from a pioneering survey covering all local political representatives in Sweden (n = 9,101, response rate 70%), we examine attitudes toward controversial noninstitutionalized forms of citizen protests. The results show that representatives to the right show considerably lower protest acceptance than those to the left. Representatives in office show significantly lower levels of acceptance than those of the opposition. Finally, the results show that representatives with more protest experience show higher protest acceptance.
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| 25. |
- Guzzi, Nicola, et al.
(författare)
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Pseudouridylation of tRNA-Derived Fragments Steers Translational Control in Stem Cells
- 2018
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Ingår i: Cell. - : Elsevier BV. - 0092-8674 .- 1097-4172. ; 173:5, s. 26-1216
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Tidskriftsartikel (refereegranskat)abstract
- Pseudouridylation (Ψ) is the most abundant and widespread type of RNA epigenetic modification in living organisms; however, the biological role of Ψ remains poorly understood. Here, we show that a Ψ-driven posttranscriptional program steers translation control to impact stem cell commitment during early embryogenesis. Mechanistically, the Ψ “writer” PUS7 modifies and activates a novel network of tRNA-derived small fragments (tRFs) targeting the translation initiation complex. PUS7 inactivation in embryonic stem cells impairs tRF-mediated translation regulation, leading to increased protein biosynthesis and defective germ layer specification. Remarkably, dysregulation of this posttranscriptional regulatory circuitry impairs hematopoietic stem cell commitment and is common to aggressive subtypes of human myelodysplastic syndromes. Our findings unveil a critical function of Ψ in directing translation control in stem cells with important implications for development and disease. Translational control in stem cells is orchestrated by pseudouridylation of specific tRNA-derived fragments, impacting stem cell commitment during key developmental processes.
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| 26. |
- He, Fei, et al.
(författare)
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FPR2 Shapes an Immune-Excluded Pancreatic Tumor Microenvironment and Drives T-cell Exhaustion in a Sex-Dependent Manner
- 2023
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Ingår i: Cancer Research. - : American Association for Cancer Research (AACR). - 0008-5472 .- 1538-7445. ; 83:10, s. 1628-1645
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Tidskriftsartikel (refereegranskat)abstract
- Sex-driven immune differences can affect tumor progression and the landscape of the tumor microenvironment. Deeper understanding of these differences in males and females can inform patient selection to improve sex-optimized immunotherapy treatments. In this study, single-cell RNA sequencing and protein analyses uncovered a subpopulation of myeloid cells in pancreatic lesions associated with an immune-excluded tumor phenotype and effector T-cell exhaustion exclusively in females. This myeloid subpopulation was positively correlated with poor survival and genetic signatures of M2-like macrophages and T-cell exhaustion in females. The G-protein coupled receptor formyl peptide receptor 2 (FPR2) mediated these immunosuppressive effects. In vitro, treatment of myeloid cells with a specific FPR2 antagonist prevented exhaustion and enhanced cytotoxicity of effector cells. Proteomic analysis revealed high expression of immunosuppressive secretory proteins PGE2 and galectin-9, enriched integrin pathway, and reduced proinflammatory signals like TNFα and IFNγ in female M2-like macrophages upon FPR2 agonist treatment. In addition, myeloid cells treated with FPR2 agonists induced TIM3 and PD-1 expression only in female T cells. Treatment with anti-TIM3 antibodies reversed T-cell exhaustion and stimulated their ability to infiltrate and kill pancreatic spheroids. In vivo, progression of syngeneic pancreatic tumors was significantly suppressed in FPR2 knockout (KO) female mice compared with wild-type (WT) female mice and to WT and FPR2 KO male mice. In female mice, inoculation of tumors with FPR2 KO macrophages significantly reduced tumor growth compared with WT macrophages. Overall, this study identified an immunosuppressive function of FPR2 in females, highlighting a potential sex-specific precision immunotherapy strategy.
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| 27. |
- Jensen, Christina T, et al.
(författare)
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Dissection of progenitor compartments resolves developmental trajectories in B-lymphopoiesis
- 2018
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Ingår i: Journal of Experimental Medicine. - : Rockefeller University Press. - 1540-9538 .- 0022-1007. ; 215:7, s. 1947-1963
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Tidskriftsartikel (refereegranskat)abstract
- To understand the developmental trajectories in early lymphocyte differentiation, we identified differentially expressed surface markers on lineage-negative lymphoid progenitors (LPs). Single-cell polymerase chain reaction experiments allowed us to link surface marker expression to that of lineage-associated transcription factors (TFs) and identify GFRA2 and BST1 as markers of early B cells. Functional analyses in vitro and in vivo as well as single-cell gene expression analyses supported that surface expression of these proteins defined distinct subpopulations that include cells from both the classical common LPs (CLPs) and Fraction A compartments. The formation of the GFRA2-expressing stages of development depended on the TF EBF1, critical both for the activation of stage-specific target genes and modulation of the epigenetic landscape. Our data show that consecutive expression of Ly6D, GFRA2, and BST1 defines a developmental trajectory linking the CLP to the CD19+ progenitor compartment.
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| 28. |
- Johansson, Mikael, 1987, et al.
(författare)
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Automation as an enabler: Passengers’ experience of travelling with a full-length automated bus and their expectations of a future public transport system
- 2023
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Ingår i: Transportation Research Procedia. - 2352-1465 .- 2352-1457. ; 72, s. 957-964
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Konferensbidrag (refereegranskat)abstract
- Twenty-two frequent public transport users experienced travelling with a fully automated, full-length bus on a test course that included nine simulated everyday traffic situations. Most participants experienced the journey as very positive and their trust in the automated system was high. In general, they were positive about using automated buses in the future but believed that this would not improve their travelling experience or change their travel behaviour without additional modifications to the system, such as dedicated public transport lanes etc. Many believed that the introduction of automated buses could create conditions for increased access to transport in rural areas and that the automated technology might enable new services that would have a great impact on public transport development, contributing a more individual, efficient and flexible public transport system.
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| 29. |
- Jonsson, Joakim H, et al.
(författare)
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Treatment planning using MRI data: an analysis of the dose calculation accuracy for different treatment regions
- 2010
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Ingår i: Radiation Oncology. - 1748-717X. ; 5, s. 62-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Because of superior soft tissue contrast, the use of magnetic resonance imaging (MRI) as a complement to computed tomography (CT) in the target definition procedure for radiotherapy is increasing. To keep the workflow simple and cost effective and to reduce patient dose, it is natural to strive for a treatment planning procedure based entirely on MRI. In the present study, we investigate the dose calculation accuracy for different treatment regions when using bulk density assignments on MRI data and compare it to treatment planning that uses CT data.METHODS: MR and CT data were collected retrospectively for 40 patients with prostate, lung, head and neck, or brain cancers. Comparisons were made between calculations on CT data with and without inhomogeneity corrections and on MRI or CT data with bulk density assignments. The bulk densities were assigned using manual segmentation of tissue, bone, lung, and air cavities.RESULTS: The deviations between calculations on CT data with inhomogeneity correction and on bulk density assigned MR data were small. The maximum difference in the number of monitor units required to reach the prescribed dose was 1.6%. This result also includes effects of possible geometrical distortions.CONCLUSIONS: The dose calculation accuracy at the investigated treatment sites is not significantly compromised when using MRI data when adequate bulk density assignments are made. With respect to treatment planning, MRI can replace CT in all steps of the treatment workflow, reducing the radiation exposure to the patient, removing any systematic registration errors that may occur when combining MR and CT, and decreasing time and cost for the extra CT investigation.
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| 30. |
- Jonsson, Joakim, 1984-
(författare)
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Integration of MRI into the radiotherapy workflow
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The modern day radiotherapy treatments are almost exclusively based on computed tomography (CT) images. The CT images are acquired using x-rays, and therefore reflect the radiation interaction properties of the material. This information is used to perform accurate dose calculation by the treatment planning system, and the data is also well suited for creating digitally reconstructed radiographs for comparing patient set up at the treatment machine where x-ray images are routinely acquired for this purpose.The magnetic resonance (MR) scanner has many attractive features for radiotherapy purposes. The soft tissue contrast as compared to CT is far superior, and it is possible to vary the sequences in order to visualize different anatomical and physiological properties of an organ. Both of these properties may contribute to an increase in accuracy of radiotherapy treatment.Using the MR images by themselves for treatment planning is, however, problematic. MR data reflects the magnetic properties of protons, and thus have no connection to the radiointeraction properties of the material. MRI also has inherent difficulty in imaging bone, which will appear in images as areas of no signal similar to air. This makes both dose calculation and patient positioning at the treatment machine troublesome.There are several clinics that use MR images together with CT images to perform treatment planning. The images are registered to a common coordinate system, a process often described as image fusion. In these cases, the MR images are primarily used for target definition and the CT images are used for dose calculations. This method is now not ideal, however, since the image fusion may introduce systematic uncertainties into the treatment due to the fact that the tumor is often able to move relatively freely with respect to the patients’ bony anatomy and outer contour, especially when the image registration algorithms take the entire patient anatomy in the volume of interest into account.The work presented in the thesis “Integration of MRI into the radiotherapy workflow” aim towards investigating the possibilities of workflows based entirely on MRI without using image registration, as well as workflows using image registration methods that are better suited for targets that can move with respect to surrounding bony anatomy, such as the prostate.
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| 31. |
- Karlsson, Dennis, et al.
(författare)
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Binder jetting of the AlCoCrFeNi alloy
- 2019
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Ingår i: Additive Manufacturing. - : Elsevier. - 2214-8604 .- 2214-7810. ; 27, s. 72-79
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Tidskriftsartikel (refereegranskat)abstract
- High density components of an AlCoCrFeNi alloy, often described as a high-entropy alloy, were manufactured by binder jetting followed by sintering. Thermodynamic calculations using the CALPHAD approach show that the high-entropy alloy is only stable as a single phase in a narrow temperature range below the melting point. At all other temperatures, the alloy will form a mixture of phases, including a sigma phase, which can strongly influence the mechanical properties. The phase stabilities in built AlCoCrFeNi components were investigated by comparing the as-sintered samples with the post-sintering annealed samples at temperatures between 900 °C and 1300 °C. The as-sintered material shows a dominant B2/bcc structure with additional fcc phase in the grain boundaries and sigma phase precipitating in the grain interior. Annealing experiments between 1000 °C and 1100 °C inhibit the sigma phase and only a B2/bcc phase with a fcc phase is observed. Increasing the temperature further suppresses the fcc phase in favor for the B2/bcc phases. The mechanical properties are, as expected, dependent on the annealing temperature, with the higher annealing temperature giving an increase in yield strength from 1203 MPa to 1461 MPa and fracture strength from 1996 MPa to 2272 MPa. This can be explained by a hierarchical microstructure with nano-sized precipitates at higher annealing temperatures. The results enlighten the importance of microstructure control, which can be utilized in order to tune the mechanical properties of these alloys. Furthermore, an excellent oxidation resistance was observed with oxide layers with a thickness of less than 5 μm after 20 h annealing at 1200 °C, which would be of great importance for industrial applications.
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| 32. |
- Karlsson, Jenny, et al.
(författare)
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RoadOpt : a decision support system for road upgrading in forestry
- 2006
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Ingår i: Scandinavian Journal of Forest Research. - : Informa UK Limited. - 0282-7581 .- 1651-1891. ; 21:S7. 7, s. 5-15
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Tidskriftsartikel (refereegranskat)abstract
- Road blocking due to thawing or heavy rains annually contributes to a considerable loss of profit in Swedish forestry. Companies have to build large stocks of sawlogs and pulplogs to secure a continuous supply during periods where the accessibility of the road network is uncertain. This storage leads to quality deterioration, which means loss in profit. One approach to reduce the losses due to blocked roads is to upgrade the road network to a standard that guarantees accessibility throughout the year. This article describes a decision support system called RoadOpt for the planning of forest road upgrading. The planning horizon is about one decade. The system uses a Geographical Information System (GIS)-based map user interface to present and analyse data and results. Two important modules are the Swedish road database, which provides detailed information about the road network, and an optimization module consisting of a mixed integer linear programming model. A case study from a major Swedish company is presented.
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| 33. |
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| 34. |
- Karlsson, Mikael, et al.
(författare)
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Beyond the limits: On Violated Environmental Quality Standards and Health Effects from Particles in Sweden
- 2006
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Konferensbidrag (refereegranskat)abstract
- The present levels of particles in the air present a serious health problem in Sweden and legal quality standards for particles are violated. The article analyses if the environmental quality standard is possible to maintain by present legislation, if the standard is based on scientific facts concerning which types of particles that are most hazardous, and if the proposed legally based action programme for counteracting particle concentrations in Stockholm beyond the limits is effective. It suggests developed legislation, a new standard for fine particles and increased focus on traffic reducing measures, if the standards are to be maintained
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| 35. |
- Karlsson, Mikael, et al.
(författare)
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Dedicated magnetic resonance imaging in the radiotherapy clinic
- 2009
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Ingår i: International journal of radiation oncology, biology, physics. - : Elsevier BV. - 1879-355X .- 0360-3016. ; 74:2, s. 644-651
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To introduce a novel technology arrangement in an integrated environment and outline the logistics model needed to incorporate dedicated magnetic resonance (MR) imaging in the radiotherapy workflow. An initial attempt was made to analyze the value and feasibility of MR-only imaging compared to computed tomography (CT) imaging, testing the assumption that MR is a better choice for target and healthy tissue delineation in radiotherapy. METHODS AND MATERIALS: A 1.5-T MR unit with a 70-cm-bore size was installed close to a linear accelerator, and a special trolley was developed for transporting patients who were fixated in advance between the MR unit and the accelerator. New MR-based workflow procedures were developed and evaluated. RESULTS: MR-only treatment planning has been facilitated, thus avoiding all registration errors between CT and MR scans, but several new aspects of MR imaging must be considered. Electron density information must be obtained by other methods. Generation of digitally reconstructed radiographs (DRR) for x-ray setup verification is not straight forward, and reliable corrections of geometrical distortions must be applied. The feasibility of MR imaging virtual simulation has been demonstrated, but a key challenge to overcome is correct determination of the skeleton, which is often needed for the traditional approach of beam modeling. The trolley solution allows for a highly precise setup for soft tissue tumors without the invasive handling of radiopaque markers. CONCLUSIONS: The new logistics model with an integrated MR unit is efficient and will allow for improved tumor definition and geometrical precision without a significant loss of dosimetric accuracy. The most significant development needed is improved bone imaging.
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| 36. |
- Karlsson, M G, et al.
(författare)
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Electron beam collimation with focused and curved leaf end MLCs - Experimental verification of Monte Carlo optimized designs
- 2002
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Ingår i: Medical physics (Lancaster). - : Wiley. - 0094-2405. ; 29:4, s. 631-637
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Tidskriftsartikel (refereegranskat)abstract
- In general, electron beams, from conventional accelerators using applicators with lead alloy inserts are not suitable for advanced conformal radiation therapy. However, interesting electron treatments have been demonstrated on a few advanced accelerators. These accelerators have been equipped with helium filled treatment heads and computer controlled MLCs that produce clinically useful energy modulated electron beams or mixed photon electron beams in an automated sequence. This study analyzes the characteristics of different MLC designs, curved and focused leaf ends in helium filled treatment heads, with respect to their effect on electron beams. In addition, this study analyzes the effects that different treatment head designs have on the output factor due to collimator scattering and shielding of secondary sources during treatment. The investigation of the different treatment head designs was performed with the Monte Carlo package BEAM and was verified by experimental methods. The results show that the difference between curved leaf ends and focused ends is negligible in most practical cases. The results also show the importance of scattering foil optimization in the optimization of parameters such as penumbra. virtual source position, and in the reduction of the output variation. In all cases, the experimental data verifies the calculations. (C) 2002 American Association of Physicists in Medicine.
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| 37. |
- Karlsson, Magnus G, et al.
(författare)
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Semi-conductor detectors in output factor measurements
- 1997
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Ingår i: Radiotherapy and Oncology. - 0167-8140 .- 1879-0887. ; 42:3, s. 293-296
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose: Output factors are generally measured with cylindrical ionization chambers. It was investigated if Si-diodes of p-type instead could be used. The advantage would be the small detector size and the robust construction of the detector. Materials and methods: Two types of diodes were studied, one with a shielding layer of tungsten specially made to reduce the excess response for scattered photons and one standard diode without any extra shielding. The measurements were performed at accelerating potentials between 4 and 50 MV and beam sizes between 4 cm x 4 cm and 40 cm x 40 cm. Results: The results showed that both types of diodes are suitable for measurements of head scatter factors in mini-phantoms. However, the diodes were found inappropriate for measurement of output factors for large fields in extended water phantoms. For small fields (<10 cm x 10 cm) a small detector is advantageous and no errors due to the scatter contribution were seen. Conclusions: An cylindrical ionization chamber is the best choice for output factor measurements in extended water phantoms for large field sizes while diodes are an alternative in small fields. There were negligible differences between the detectors in head scatter measurements in mini phantoms.
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| 38. |
- Karlsson, M G, et al.
(författare)
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Treatment head design for multileaf collimated high-energy electrons
- 1999
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Ingår i: Medical physics (Lancaster). - 0094-2405. ; 26:10, s. 2161-2167
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes how a conventional treatment head can be modified for use of multileaf collimated electron beams. Automatic and dynamic beam delivery are possible for both electrons and photons by using the computer controlled multileaf collimator (MLC) for both photon and electron beams. Thereby, the electron beams can be mixed more freely into the treatment to take advantage of the specific depth modulation characteristics of electrons. The investigation was based on Monte Carlo calculations using the software package BEAM. The physical parameters used in this optimization were the beam penumbra and the virtual/effective point source position. These parameters are essential for shaping beams, beam matching and for dosimetry calculations. The optimization was carried out by modifying a number of parameters: replacing the air atmosphere in the treatment head with helium, adding a helium bag below the MLC, changing the position of the scattering foils, modifying the monitor chamber, and adjusting the position of the MLC. The beam characteristics for some of these designs were found to fulfil our criteria for clinically useful beams down to at least 9 MeV. (C) 1999 American Association of Physicists in Medicine. [S0094-2405(99)00610-0].
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| 39. |
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| 40. |
- Karlsson, Mikael, et al.
(författare)
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MR-only procedures for improved overall precision in radiotherapy
- 2009
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Ingår i: International Journal of Radiation Oncology Biology Physics. - : Elsevier BV. - 0360-3016. ; , s. S656-S656
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Konferensbidrag (refereegranskat)abstract
- Purpose/Objective(s) To reduce the overall geometrical uncertainty in radiotherapy by introducing a novel technology arrangement based on a dedicated MR in an integrated workflow. A new logistics model needed to incorporate MR in this way was developed and clinically evaluated. Testing the assumption that MR is a better choice for target and healthy tissue delineation in radiotherapy, the suggested procedure was analyzed with respect to feasibility and precision of MR-only imaging compared to CT. The focus of the present study was on the geometrical uncertainty which is connected to the required margins between PTV and CTV. Materials/Methods A 1.5-T “open bore” MR unit with a 70-cm-bore size, Siemens Espree, was installed in close proximity to a treatment unit. A new MR-based workflow procedure was developed where all target drawing and treatment planning was performed on MR-data only. For non-fixed soft tissue targets, e.g. prostate, a special trolley was developed for transporting patients, who were immobilized, between the MR unit and the accelerator. The geometrical uncertainty using the transport solution was added to the uncertainty originating from the target definition process and compared with the total uncertainty in a more conventional CT based workflow. Results MR-only treatment planning has been facilitated, thus avoiding all registration errors between CT and MR data, but several new aspects of MR imaging must be considered. Reliable corrections of geometrical distortions must be applied and electron density information must be obtained by other methods. The feasibility of MR virtual simulation has previously been demonstrated. However, a key challenge is improve the visualization of skeletal structures, which is often needed for the traditional approach of set-up verification. The trolley solution allows for a highly precise setup of soft tissue targets without the invasive handling of fiducial markers. In the overall analyses of geometrical uncertainties it was shown that the combined uncertainty is reduced with the MR based workflow, mostly because of reduced systematic uncertainties when the CT-image registration is avoided. Conclusions The new logistics model is efficient and will allow for improved tumor definition and geometrical precision without a significant loss of dosimetric accuracy. Treatment planning directly on MR images is a way to reduce the geometrical uncertainty for e.g. prostate treatments. MR aided patient positioning does not require implanted fiducial markers and will be facilitated by rigid MR-MR registration. Less precise soft tissue CT-CT or CT-MR registrations will thus be avoided.
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| 41. |
- Karlsson, O. Andreas, et al.
(författare)
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Design of a PDZbody, a bivalent binder of the E6 protein from human papillomavirus
- 2015
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Chronic infection by high risk human papillomavirus (HPV) strains may lead to cancer. Expression of the two viral oncoproteins E6 and E7 is largely responsible for immortalization of infected cells. The HPV E6 is a small (approximately 150 residues) two domain protein that interacts with a number of cellular proteins including the ubiquitin ligase E6-associated protein (E6AP) and several PDZ-domain containing proteins. Our aim was to design a high-affinity binder for HPV E6 by linking two of its cellular targets. First, we improved the affinity of the second PDZ domain from SAP97 for the C-terminus of HPV E6 from the high-risk strain HPV18 using phage display. Second, we added a helix from E6AP to the N-terminus of the optimized PDZ variant, creating a chimeric bivalent binder, denoted PDZbody. Full-length HPV E6 proteins are difficult to express and purify. Nevertheless, we could measure the affinity of the PDZbody for E6 from another high-risk strain, HPV16 (K-d = 65 nM). Finally, the PDZbody was used to co-immunoprecipitate E6 protein from HPV18-immortalized HeLa cells, confirming the interaction between PDZbody and HPV18 E6 in a cellular context.
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| 42. |
- Karlsson, Stefan, et al.
(författare)
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“Transparent Intelligence” for Sustainable Development
- 2018
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Ingår i: Abstracts. ; , s. 208-
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Konferensbidrag (refereegranskat)abstract
- Transparent materials are essential in everyone’s life. They enable daylight to reach the interior of buildings, thereby contributing to both our physical and mental well-being; they are the primary component for communication via optical fibers and a key component in electronic devices such as protective cover and/or dielectric material; and they enable clean energy production through solar panels or algae reactors by acting as protective and light transmitting barriers. Adding functions to transparent materials in an intelligent way creates further opportunities to use and enhance the beneficial impacts of transparency. The concept Transparent Intelligence covers transparent materials and products with integral intelligent functions – passive, active or interactive. By using Transparent Intelligence it is possible to embrace many of the societal challenges that we are facing today. The concept can be divided into five broad industrial sectors: Built Environment, Information and Communication Technologies (ICT), Solar Energy, Mobility, and Materials. A perspective on how Transparent Intelligence can improve the sustainable development of our world will be presented, using examples of electrochromic windows for energy-efficient buildings, photocatalytic coatings for improved indoor air quality, transparent conductive coatings for antennas, bandpass filters for mobile phone indoor coverage, UV down-converting components for efficient solar energy, hygienic surfaces for infection mitigation on electronic devices, printed electronics for sustainable glass packaging, and IR-reflecting coatings for fire safety.
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| 43. |
- Kullander, Sven, 1952-, et al.
(författare)
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Chalinochromis cyanophleps, a new species of cichlid fish (Teleostei: Cichlidae) from Lake Tanganyika
- 2014
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Ingår i: Zootaxa. - : Magnolia Press. - 1175-5326 .- 1175-5334. ; 3790:3, s. 425-438
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Tidskriftsartikel (refereegranskat)abstract
- Chalinochromis cyanophleps is described from nine specimens, the largest 129 mm SL, from Namansi. It differs fromother species of Chalinochromis in plain trunk colouration, absence of black stripes on the head, relatively narrow lips, presence of tricuspid jaw teeth, and presence of five rather than four dentary lateralis foramina. The blue iridescent stripe below the eye is shared with other lamprologin cichlids, but is broader and more conspicuous in C. cyanophleps. Chalinochromis cyanophleps occurs at depths between 6 and 45 m in rocky habitats along the Tanzanian coast of Lake Tanganyika,from Mvuna Island south to Kalala Island, a stretch of about 90 km. Field observations were made of specimens up to 18 cm total length. The COI DNA barcode sequence differs by 1.8% from that of C. popelini.
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| 44. |
- Kullander, Sven, 1952-, et al.
(författare)
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Description of Neolamprologus timidus, new species, and review of N. furcifer from Lake Tanganyika (Teleostei: Cichlidae)
- 2013
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Ingår i: Ichthyological Exploration of Freshwaters. - München : Verlag Dr. Friedrich Pfeil. - 0936-9902. ; 24:4, s. 301-328
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Tidskriftsartikel (refereegranskat)abstract
- Neolamprologus timidus, new species, is described from Ulwile Island and adjacent localities on the Tanzanian coast of Lake Tanganyika. The species was observed or collected along about 100 km of coastline from KolwePoint, Cape Mpimbwe, south to Kisi Island. It is distinguished from the most similar species, N. furcifer, by presenceof scales on most of the cheek, long pectoral fin and pelvic fin with the second ray longer than the first. Neolamprologus timidus is sympatric with N. furcifer at Kolwe Point and south to Kampempa Point, and at Lupitaand Ulwile Islands south to Kisi Island, but N. furcifer is otherwise absent from the range of N. timidus. Two morphologically distinct forms are recognized in N. furcifer. Samples of N. furcifer from Ulwile Island and slightly more southern localities possess a caudal fin with rounded lobes and long middle rays, appearing onlyslightly emarginate. Samples of N. furcifer from Udachi and nearby localities possess pointed caudal-fin lobeswith greatly elongated streamers, similar to N. timidus and to N. furcifer from other parts of Lake Tanganyika, including the type specimens from the southern part of the lake. The variation in caudal-fin shape may be an expression of character displacement as it occurs in the area of sympatry between N. timidus and N. furcifer. MitochondrialDNA sequences are nearly identical in samples of N. furcifer with pointed or rounded caudal fin. A molecular phylogenetic analysis of a large set of lamprologin cichlids using two mitochondrial genes corroborates earlier analyses and places N. furcifer and N. timidus in different clades with different species of Neolamprologus, Julidochromis, Chalinochromis, and Telmatochromis despite sharing a unique combination of fin and bodyshape, and colour pattern. A 4648 base-pair multiloci analysis of a smaller number of species using fragments ofthree mitochondrial and two nuclear genes resolves N. furcifer and N. timidus in sister clades, but the N. timidus clade also includes Telmatochromis brachygnathus, and N. furcifer is sister species of Chalinochromis brichardi.
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| 45. |
- Lind, Mikael, et al.
(författare)
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Punctuality as performance metrics for efficient transportation systems
- 2014
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Ingår i: 21st World Congress on Intelligent Transport Systems, ITSWC 2014. - : Intelligent Transport Systems (ITS).
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Konferensbidrag (refereegranskat)abstract
- Transportation systems are ecosystems building on a high degree of co-production of value performed by multiple actors. In order to guide involved actors and ensure expected performance it becomes necessary to have an agreed performance metrics. Beside operational capacity for the transportation systems as such it is believed that punctuality as a performance metrics would be a solid base enabling different actors to take appropriate actions in planning, realizing, and evaluating their actions in relation to the expectations among involved actors (including beneficiaries) of the transportation system. In this paper, underlying mechanisms for punctuality are explored as the basis for an efficient transportation system.
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| 46. |
- Lindborg, M. N., et al.
(författare)
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Acoustic characterization of shallow flow reversal chambers
- 2011
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Konferensbidrag (refereegranskat)abstract
- Flow reversal chambers are common design elements in mufflers. Here an idealized flow reversal chamber with large cross-section but small depth has been studied. The inlet and outlet ducts as well as the cross-sectional area are fixed while the depth of the chamber can be varied. The resulting systems are then characterized experimentally using the two-microphone wave decomposition method and compared with results from both finite element modeling and various approaches using two-port elements. The finite element modeling results are in excellent agreement with the measurements over the whole frequency range studied, while two-port modeling can be used with engineering precision in the low frequency range. The influence of mean flow was studied experimentally and was shown to have relatively small influence, mainly adding some additional losses at low frequencies. This study yields an insight into the modeling approach necessary to capture the acoustical behavior of a flow reversal chamber. For initial studies of the performance the recommendation is to model the flow reversal as a straight duct two-port element connecting the inlet and outlet. For more in depth studies finite element modeling should be used to construct a two-port element for inclusion in a network model.
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| 47. |
- Lindgren, Oskar, et al.
(författare)
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Exploring sufficiency in energy policy : insights from Sweden
- 2023
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Ingår i: Sustainability. - Stockholm : Taylor & Francis. - 1548-7733. ; 19:1
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Tidskriftsartikel (refereegranskat)abstract
- Energy efficiency and renewable energy strategies have been insufficient in achieving rapid and profound reductions of energy-related greenhouse-gas (GHG) emissions. Consequently, energy sufficiency has gained attention as a complementary strategy over the past two decades. Yet, most research on energy sufficiency has been theoretical and its implementation in policy limited. This study draws on the growing sufficiency literature to examine the presence of sufficiency as a strategy for reducing energy-related GHG emissions in Sweden, a country often regarded as a "climate-progressive" country. By conducting a keyword and content analysis of energy policies and parliamentary debates during four governmental terms of office (2006-2022), this research explores the extent to which sufficiency is integrated into Swedish energy policy, as well as potential barriers to its adoption. The analyses revealed a scarcity of sufficiency elements. Although some policies could potentially result in energy savings, they are infrequent and overshadowed by the prevailing emphasis on efficiency and renewable energy. Furthermore, Sweden lacks a target for sufficiency or absolute energy reductions. The main impediments to sufficiency implementation include the disregard of scientific evidence in the policy-making process and the perceived contradiction between sufficiency and industrial competitiveness. This study thus concludes that sufficiency at best remains at the periphery of Swedish energy policy. Given the reinforced ambitions within the European Union, this raises questions regarding the validity of Sweden's reputation as a climate-progressive country.
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| 48. |
- Malmstrom, Mikael, et al.
(författare)
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Waveguides in polycrystalline diamond for mid-IR sensing
- 2016
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Ingår i: Optical Materials Express. - 2159-3930 .- 2159-3930. ; 6:4, s. 1286-1295
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Tidskriftsartikel (refereegranskat)abstract
- 8 mm long channel waveguides were manufactured in polycrystalline diamond with inductively coupled plasma etching and characterized in terms of mode-profile and propagation loss in the 1.5 - 3.4 mu m spectral region. As proof of principle, the waveguides were evaluated in an evanescent field sensing setup targeting the CH absorption peak of isopropanol at similar to 3.4 mu m, showing good agreement with numerical finite element simulations. (C) 2016 Optical Society of America
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| 49. |
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| 50. |
- Malmström, Mikael, 1982-, et al.
(författare)
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Diamond waveguides for mid-IR sensing
- 2014
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Ingår i: Optics & Photonics in Sweden. ; , s. 1-1
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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