| 1. |
- Abulaiti, Yiming, et al.
(författare)
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Measurements of W(+/-)Z production cross sections in pp collisions at root s=8 TeV with the ATLAS detector and limits on anomalous gauge boson self-couplings
- 2016
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Ingår i: Physical Review D. - : American Physical Society. - 2470-0010. ; 93:9
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents measurements of W(+/-)Z production in pp collisions at a center-of-mass energy of 8 TeV. The gauge bosons are reconstructed using their leptonic decay modes into electrons and muons. The data were collected in 2012 by the ATLAS experiment at the Large Hadron Collider and correspond to an integrated luminosity of 20.3 fb(-1). The measured inclusive cross section in the detector fiducial region is sigma W(+/-)Z -> l'nu ll = 35.1 +/- 0.9(stat) +/- 0.8(sys) +/- 0.8(lumi) fb, for one leptonic decay channel. In comparison, the next-to-leading-order Standard Model expectation is 30.0 +/- 2.1 fb. Cross sections for W(+)Z and W(-)Z production and their ratio are presented as well as differential cross sections for several kinematic observables. Limits on anomalous triple gauge boson couplings are derived from the transverse mass spectrum of the W(+/-)Z system. From the analysis of events with a W and a Z boson associated with two or more forward jets an upper limit at 95% confidence level on the W(+/-)Z scattering cross section of 0.63 fb, for each leptonic decay channel, is established, while the Standard Model prediction at next-to-leading order is 0.13 +/- 0.01 fb. Limits on anomalous quartic gauge boson couplings are also extracted.
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| 2. |
- Abulaiti, Yiming, et al.
(författare)
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Search for a high-mass Higgs boson decaying to a W boson pair in pp collisions at root s=8TeV with the ATLAS detector
- 2016
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Ingår i: Journal of High Energy Physics (JHEP). - 1126-6708 .- 1029-8479. ; :1
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Tidskriftsartikel (refereegranskat)abstract
- A search for a high-mass Higgs boson H is performed in the H -> WW -> l nu l nu and H -> WW -> l nu qq decay channels using pp collision data corresponding to an integrated luminosity of 20.3 fb(-1) collected at root s = 8TeV by the ATLAS detector at the Large Hadron Collider. No evidence of a high-mass Higgs boson is found. Limits on sigma(H) x BR(H -> WW) as a function of the Higgs boson mass m(H) are determined in three different scenarios: one in which the heavy Higgs boson has a narrow width compared to the experimental resolution, one for a width increasing with the boson mass and modeled by the complex-pole scheme following the same behavior as in the Standard Model, and one for intermediate widths. The upper range of the search is m(H) = 1500 GeV for the narrow-width scenario and m(H) = 1000 GeV for the other two scenarios. The lower edge of the search range is 200{300 GeV and depends on the analysis channel and search scenario. For each signal interpretation, individual and combined limits from the two WW decay channels are presented. At m(H) = 1500 GeV, the highest-mass point tested, sigma(H) x BR(H -> WW) for a narrow-width Higgs boson is constrained to be less than 22 fb and 6.6 fb at 95% CL for the gluon fusion and vector-boson fusion production modes, respectively.
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| 3. |
- Abulaiti, Yiming, et al.
(författare)
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Search for invisible decays of a Higgs boson using vector-boson fusion in pp collisions at root s=8 TeV with the ATLAS detector
- 2016
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Ingår i: Journal of High Energy Physics (JHEP). - : Springer. - 1126-6708 .- 1029-8479. ; :1
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Tidskriftsartikel (refereegranskat)abstract
- A search for a Higgs boson produced via vector-boson fusion and decaying into invisible particles is presented, using 20.3 fb(-1) of proton-proton collision data at a centre-of-mass energy of 8TeV recorded by the ATLAS detector at the LHC. For a Higgs boson with a mass of 125 GeV, assuming the Standard Model production cross section, an upper bound of 0.28 is set on the branching fraction of H -> invisible at 95% confidence level, where the expected upper limit is 0.31. The results are interpreted in models of Higgs-portal dark matter where the branching fraction limit is converted into upper bounds on the dark-matter-nucleon scattering cross section as a function of the dark-matter particle mass, and compared to results from the direct dark-matter detection experiments.
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| 4. |
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| 5. |
- Ahlgren, Per, et al.
(författare)
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Uppsala University Annual Bibliometric Monitoring 2020
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Uppsala University Annual Bibliometric Monitoring produces statistics on publication volume, publishing level, citation impact, collaboration (in terms of co-publishing) and open access. The aggregation level is primarily department, which means that it is primarily the departments of Uppsala University that are the units of analysis in the monitoring. Two main data sources are used: the local publication database of Uppsala University, DiVA, and the in-house version of the Web of Science database available at the Centre for Science and Technology Studies at Leiden University, the Netherlands. The considered publication period is 2011-2019. The results are presented in graphs or in tables, and in the next to last section, the results are briefly summarized. Regarding the domain Humanities and Social Sciences, the indicator proportion of publication fractions at level 2 (in the Norwegian model), the departments Economics and Peace and Conflict Studies have the highest values for the last three considered publication years. The highest values on the citation indicators, with respect to the domain Medicine and Pharmacy and the whole publication period, are observed for the three departments Medical Biochemistry and Microbiology, Immunology, Genetics and Pathology and Pharmacy. For the domain Science and Technology, the three biology departments, Cell and Molecular Biology, Ecology and Genetics and Organismal Biology, all have high values on the citation indicators with respect to the whole publication period.
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| 6. |
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| 7. |
- Andersson, Niklas, et al.
(författare)
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Calibration of a polyethylene plant for grade change optimisations
- 2011
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Ingår i: 21ST European Symposium on Computer Aided Process Engineering. - 1570-7946. - 9780444538956 ; 29, s. 673-677
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Konferensbidrag (refereegranskat)abstract
- A polyethylene plant model coded in Modelica and based on a nonlinear MPC model currently used at Borealis AB is considered for calibration. A case study of model calibration at steady-state for four different operating points are analysed, both when looking at one operating point separately, but also to calibrate several simultaneously. Both model parameters and reactor inputs are calibrated for true plant measurement data. To solve the parameter estimation problem, the JModelica.org platform is used, offering tools to express and solve calibration problems. Calibration was obtained with narrow confidence intervals and shows a potential to improve the model accuracy by changing the parameter values. The results will be used for dynamic optimisations of grade changes.
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| 8. |
- Andersson, Niklas, et al.
(författare)
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Parameter Selection in the Parameter Estimation of Grade Transitions in a Polyethylene Plant
- 2015
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Ingår i: Studies in Engineering and Technology. - : Redfame Publishing. - 2330-2038 .- 2330-2046. ; 3:1, s. 1-18
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Tidskriftsartikel (refereegranskat)abstract
- A polyethylene plant at Borealis AB is modelled in the Modelica language and considered for parameter estimations at grade transitions. Parameters have been estimated for both the steady-state and the dynamic case using the JModelica.org platform, which offers tools for steady-state parameter estimation and supports simulation with parameter sensitivies. The model contains 31 candidate parameters, giving a huge amount of possible parameter combinations. The best parameter sets have been chosen using a parameter-selection algorithm that identified parameter sets with poor numerical properties. The parameter-selection algorithm reduces the number of parameter sets that is necessary to explore. The steady-state differs from the dynamic case with respect to parameter selection. Validations of the parameter estimations in the dynamic case show a significant reduction in an objective value used to evaluate the quality of the solution from that of the nominal reference, where the nominal parameter values are used.
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| 9. |
- Axelsson, Jan Peter, et al.
(författare)
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A Probing Approach for Detection of Acetate Formation
- 1998
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Konferensbidrag (refereegranskat)abstract
- Many pharmaceuticals are today produced using genetically modified microorganisms. A typical problem in monitoring and control of biotechnical processes is that many important process variables cannot be measured on-line. This has triggered much research and development concerning new sensors. Another way of addressing the problem is to improve and to extend the use of existing sensors.
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| 10. |
- Axelsson, Jan Peter, et al.
(författare)
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A Probing Feeding Strategy for E. coli Cultivations
- 1999
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Ingår i: Abstract book of 217th ACS National Meeting.
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Konferensbidrag (refereegranskat)abstract
- Accumulation of acetate tends to reduce growth and recombinant protein production in E. coli cultivations. Formation of acetate can be avoided by a proper substrate feeding strategy, but most strategies require considerable process knowledge to work well. A feedback strategy is presented that requires minimal a priori information. The key idea is to exploit a characteristic change in the cell metabolism at the onset of acetate formation. By superimposing short pulses in the substrate feed rate, on-line detection of acetate formation can be made using a standard dissolved oxygen sensor. A simple feedback algorithm is then used to adjust the feed rate to avoid acetate formation while maintaining a high growth rate. The strategy was used in fed-batch cultivations of recombinant E. coli. Acetate accumulation was avoided and a good production of recombinant protein could be achieved at the first attempt for each genetic construction.
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