| 1. |
- Aad, G., et al.
(författare)
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The ATLAS Experiment at the CERN Large Hadron Collider
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 3:S08003
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Forskningsöversikt (refereegranskat)abstract
- The ATLAS detector as installed in its experimental cavern at point 1 at CERN is described in this paper. A brief overview of the expected performance of the detector when the Large Hadron Collider begins operation is also presented.
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| 2. |
- Andersson, Anders, et al.
(författare)
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Global analysis of mRNA stability in the archaeon Sulfolobus
- 2006
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Ingår i: Genome Biology. - : Springer Science and Business Media LLC. - 1465-6906 .- 1474-760X. ; 7:10, s. R99-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Transcript half-lives differ between organisms, and between groups of genes within the same organism. The mechanisms underlying these differences are not clear, nor are the biochemical properties that determine the stability of a transcript. To address these issues, genome-wide mRNA decay studies have been conducted in eukaryotes and bacteria. In contrast, relatively little is known about RNA stability in the third domain of life, Archaea. Here, we present a microarray-based analysis of mRNA half-lives in the hyperthermophilic crenarchaea Sulfolobus solfataricus and Sulfolobus acidocaldarius, constituting the first genome-wide study of RNA decay in archaea. Results: The two transcriptomes displayed similar half-life distributions, with medians of about five minutes. Growth-related genes, such as those involved in transcription, translation and energy production, were over-represented among unstable transcripts, whereas uncharacterized genes were over-represented among the most stable. Half-life was negatively correlated with transcript abundance and, unlike the situation in other organisms, also negatively correlated with transcript length. Conclusion: The mRNA half-life distribution of Sulfolobus species is similar to those of much faster growing bacteria, contrasting with the earlier observation that median mRNA half-life is proportional to the minimal length of the cell cycle. Instead, short half-lives may be a general feature of prokaryotic transcriptomes, possibly related to the absence of a nucleus and/or more limited post-transcriptional regulatory mechanisms. The pattern of growth-related transcripts being among the least stable in Sulfolobus may also indicate that the short half-lives reflect a necessity to rapidly reprogram gene expression upon sudden changes in environmental conditions.
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| 3. |
- Andersson, Kerstin I, et al.
(författare)
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Lignin removal from wastewater by adsorption
- 2009
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Ingår i: Proceedings - 2009 International Mechanical Pulping Conference, IMPC 2009. ; , s. 280-285
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Konferensbidrag (refereegranskat)abstract
- Lignin contributes to residual COD in wastewater after biological treatment. Available methods for removal of recalcitrant material like lignin, e.g. chemical oxidation and coagulation, are associated with heavy operational expenses. Stringent discharge requirements demand new cost-effective methods for removal of recalcitrant COD. Adsorption is an important mechanism for lignin removal in biological wastewater treatment. A study of lignin, using activated carbon as a model adsorbent, was performed to learn more about the adsorption behaviour of lignin. At the adsorbent dose 4 g/L and an initial lignin concentration of 0.5 g/L, 77% of the lignin was removed after six hours. The adsorption kinetics was found to follow the pseudo second-order rate expression and no temperature dependency could be observed in the temperature range studied.
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| 4. |
- Berglund, Svante, et al.
(författare)
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The ATLAS Tile Calorimeter Digitizer
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221. ; :3, s. P01004-
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Tidskriftsartikel (refereegranskat)
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| 5. |
- Börvik, Tore, et al.
(författare)
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Experimental and numerical study on the perforation of AA6005-T6 panels
- 2005
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Ingår i: International Journal of Impact Engineering. - : Elsevier BV. - 0734-743X .- 1879-3509. ; 32:1-4, s. 35-64
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Tidskriftsartikel (refereegranskat)abstract
- Extruded aluminium panels find their use in many different structures such as offshore platforms, bridge decks, train and ship components and lightweight protection systems. Impacts or other types of high-speed loading conditions are thus a relevant issue for several of these applications. There are, however, not many investigations published on the perforation of extruded aluminium panels covering experiments in combination with numerical analyses. This paper presents an experimental and numerical study on the perforation of AA6005-T6 aluminium panels impacted by ogival-nosed steel projectiles. The chosen panel has three triangular-shaped cells with a total depth of 130 mm. The wall thickness is 6 mm in the front and rear side plate, and 3 mm in the slanting webs. A rather comprehensive material test programme has been carried out in order to determine the material's response to dynamic loading. The experimental results were used to calibrate slightly modified versions of the Johnson-Cook constitutive relation and fracture criterion. 3D numerical simulations of the perforation process were then performed on a high-performance computer using the MPP version of the explicit finite element code LS-DYNA. In the simulations, the typical dimension of the elements was less than 1 mm. The numerical model is able to capture the main trends in the experiments in an adequate manner, and excellent agreement between numerical and experimental results is obtained.
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| 6. |
- Ekberg, Joakim, et al.
(författare)
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Impact of precautionary behaviors during outbreaks of pandemic influenza : modeling of regional differences
- 2009
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Ingår i: AMIA Annual Symposium Proceedings. - Rockville Pike, Bethesda MD, 20894 USA : American Medical Informatics Association. - 1942-597X. ; 2009, s. 163-167
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Tidskriftsartikel (refereegranskat)abstract
- Using time geographic theory for representation of population mixing, we set out to analyze the relative impact from precautionary behaviors on outbreaks of pandemic influenza in Europe and Asia. We extended an existing simulator environment with behavioral parameters from a population survey to model different behaviors. We found that precautionary behaviors even among a minority of the population can have a decisive effect on the probability of the outbreak to propagate. The results also display that assumptions strongly influences the outcome. Depending on the interpretation of how many "children" are kept from "school", R(0) changes from a range where outbreak progression is possible to a range where it is improbable in both European (R(0)=1.77/1.23) and Asian (R(0)=1.70/1.05) conditions. We conclude that unprompted distancing can have a decisive effect on pandemic propagation. An important response strategy can be to promote voluntary precautionary behavior shown to reduce disease transmission.
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| 7. |
- Eriksson, Mikael, et al.
(författare)
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MAX-IV Design: Pushing the Envelope
- 2007
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Ingår i: 2007 IEEE Particle Accelerator Conference, vols 1-11. - 9781424409167 ; , s. 1277-1279
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Konferensbidrag (refereegranskat)abstract
- The proposed MAX IV facility is meant as a successor to the existing MAX-lab. The accelerator part will consist of three storage rings, two new ones operated at 3 and 1.5 GeV respectively and the existing 700 MeV MAX III ring. The two new rings have identical lattices and are placed on top of each other. Both these rings have a very small emittance, 0.86 and 0.4 nm rad respectively, and offer synchrotron radiation of very high mean brilliance. As an injector, a 3 GeV linear accelerator is planned. The design philosophy and the special technical solutions called for are presented in this paper.
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| 8. |
- Eriksson, Mikael, et al.
(författare)
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STATUS OF THE MAX IV LIGHT SOURCE PROJECT
- 2006
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Ingår i: European Particle Accelerator Conference 2006, Edinburgh, UK.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 9. |
- Johansson, Karl-Axel, et al.
(författare)
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The quality assurance process for the ARTSCAN head and neck study - a practical interactive approach for QA in 3DCRT and IMRT.
- 2008
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Ingår i: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 87:2, s. 290-9
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Tidskriftsartikel (refereegranskat)abstract
- AIM: This paper describes the quality assurance (QA) work performed in the Swedish multicenter ARTSCAN (Accelerated RadioTherapy of Squamous cell CArcinomas in the head and Neck) trial to guarantee high quality in a multicenter study which involved modern radiotherapy such as 3DCRT or IMRT. MATERIALS AND METHODS: The study was closed in June 2006 with 750 randomised patients. Radiation therapy-related data for every patient were sent by each participating centre to the QA office where all trial data were reviewed, analysed and stored. In case of any deviation from the protocol, an interactive process was started between the QA office and the local responsible clinician and/or physicist to increase the compliance to the protocol for future randomised patients. Meetings and workshops were held on a regular basis for discussions on various trial-related issues and for the QA office to report on updated results. RESULTS AND DISCUSSION: This review covers the 734 patients out of a total of 750 who had entered the study. Deviations early in the study were corrected so that the overall compliance to the protocol was very high. There were only negligible variations in doses and dose distributions to target volumes for each specific site and stage. The quality of the treatments was high. Furthermore, an extensive database of treatment parameters was accumulated for future dose-volume vs. endpoint evaluations. CONCLUSIONS: This comprehensive QA programme increased the probability to draw firm conclusions from our study and may serve as a concept for QA work in future radiotherapy trials where comparatively small effects are searched for in a heterogeneous tumour population.
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| 10. |
- Odd-Geir, Lademo, et al.
(författare)
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A model for process-based crash simulation
- 2008
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Ingår i: International Journal of Impact Engineering. - : Elsevier BV. - 0734-743X .- 1879-3509. ; 35:5, s. 376-388
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Tidskriftsartikel (refereegranskat)abstract
- Manufacturing of a bumper system from aluminium extrusions often involves series of forming operations performed in the soft W-temper condition, and then artificially age-hardening of the components to the material's peak hardness T6 condition. It is probable that proper finite element (FE) modelling of the crash performance of the resulting systems must rely upon a geometry obtained from an FE model following the process route, i.e., including simulation of all major forming operations. The forming operations also result in an inhomogeneous evolution of some internal variables (among others the effective plastic strain) within the shaped components. Results from tensile tests reveal that plastic straining in W-temper leads to a significant change of the T6 work-hardening curves. In addition, the tests show that the plastic pre-deformation causes a reduction of the elongation of the T6 specimens. In the present work, these process effects have been included in a user-defined elastoplastic constitutive model in LS-DYNA incorporating a state-of-the-art anisotropic yield criterion, the associated flow rule and a non-linear isotropic work hardening rule as well as some ductile fracture criteria. A first demonstration and assessment of the modelling methodology is shown by ‘through-process analysis' of two uniaxial tensile test series. The industrial use and relevance of the modelling technique is subsequently demonstrated by a case study on an industrial bumper beam system.
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