| 1. |
- Journeau, C., et al.
(författare)
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European Research on the Corium issues within the SARNET network of excellence
- 2008
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Ingår i: International Conference on Advances in Nuclear Power Plants, ICAPP 2008. - 9781605607870 ; , s. 1172-1181
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Konferensbidrag (refereegranskat)abstract
- Within SARNET, the corium topic covers all the behaviors of corium from early phase of core degradation to in or ex-vessel corium recovery with the exception of corium interaction with water, direct containment heating and fission product release. The corium topic regroups in three work packages the critical mass of competence required to improve significantly the corium behavior knowledge. The spirit of the SARNET networking is to share the knowledge, the facilities and the simulation tools for severe accidents, so to reach a better efficiency and to rationalize the R&D effort at European level. Extensive benchmarking has been launched in most of the areas of research. These benchmarks were mainly dedicated to the recalculation of experiments, while, in the next periods, a larger focus will be given to integral experiments or reactor applications. Eventually, all the knowledge will be accumulated in the ASTEC severe accident simulation code through physical model improvements and extension of validation database. This paper summarizes the progress that has been achieved in the frame of the networking activities. A special focus is placed on the melt pool and debris coolability and corium-concrete interaction, in which, the effects due to multidimensional geometries and heterogeneities has been shown, during SARNET, to play a crucial role and for which further research is still needed.
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| 2. |
- Ricaud, P., et al.
(författare)
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Polar Vortex Evolution during the 2002 Antarctic Major Warming as Observed by the Odin Satellite
- 2005
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Ingår i: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 110:D5, s. 1-12
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Tidskriftsartikel (refereegranskat)abstract
- In September 2002 the Antarctic polar vortex split in two under the influence of a sudden warming. During this event, the Odin satellite was able to measure both ozone (O(3)) and chlorine monoxide (ClO), a key constituent responsible for the so-called "ozone hole'', together with nitrous oxide (N(2)O), a dynamical tracer, and nitric acid (HNO(3)) and nitrogen dioxide (NO(2)), tracers of denitrification. The submillimeter radiometer (SMR) microwave instrument and the Optical Spectrograph and Infrared Imager System (OSIRIS) UV-visible light spectrometer (VIS) and IR instrument on board Odin have sounded the polar vortex during three different periods: before (19-20 September), during (24-25 September), and after (1-2 and 4-5 October) the vortex split. Odin observations coupled with the Reactive Processes Ruling the Ozone Budget in the Stratosphere (REPROBUS) chemical transport model at and above 500 K isentropic surfaces (heights above 18 km) reveal that on 19-20 September the Antarctic vortex was dynamically stable and chemically nominal: denitrified, with a nearly complete chlorine activation, and a 70% O(3) loss at 500 K. On 25-26 September the unusual morphology of the vortex is monitored by the N(2)O observations. The measured ClO decay is consistent with other observations performed in 2002 and in the past. The vortex split episode is followed by a nearly complete deactivation of the ClO radicals on 1-2 October, leading to the end of the chemical O(3) loss, while HNO(3) and NO(2) fields start increasing. This acceleration of the chlorine deactivation results from the warming of the Antarctic vortex in 2002, putting an early end to the polar stratospheric cloud season. The model simulation suggests that the vortex elongation toward regions of strong solar irradiance also favored the rapid reformation of ClONO(2). The observed dynamical and chemical evolution of the 2002 polar vortex is qualitatively well reproduced by REPROBUS. Quantitative differences are mainly attributable to the too weak amounts of HNO(3) in the model, which do not produce enough NO(2) in presence of sunlight to deactivate chlorine as fast as observed by Odin.
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| 3. |
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| 4. |
- Blad, Sofia, et al.
(författare)
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Assessment of fetal reactivity biopatterns during labour by fetal ECG analysis
- 2009
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Konferensbidrag (refereegranskat)abstract
- Reactivity is the pattern of reactions associated with response to changes in the environment such as stress. Labour with uterine contractions hampering fetal and uterine blood flow provides significant stress and we need to improve our ability to assess fetal reactivity biopatterns during delivery. The study illustrates progress made with regard to detailed analysis of the fetal heart rate (FHR) and beat-to-beat variations (RR-intervals) as a clinical measure of fetal reactivity. A method, named residuals, is presented of using a small set of index cases to identify parameter settings which are then further evaluated in extensive database tests of 8100 cases.
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| 5. |
- Egecioglu, Emil, 1977, et al.
(författare)
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Central NMU signaling in body weight and energy balance regulation: evidence from NMUR2 deletion and chronic central NMU treatment in mice.
- 2009
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Ingår i: American journal of physiology. Endocrinology and metabolism. - : American Physiological Society. - 1522-1555 .- 0193-1849. ; 297:3
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Tidskriftsartikel (refereegranskat)abstract
- To investigate the role of the central neuromedin U (NMU) signaling system in body weight and energy balance regulation, we examined the effects of long-term intracerebroventricular (icv) infusion of NMU in C57Bl/6 mice and in mice lacking the gene encoding NMU receptor 2. In diet-induced obese male and female C57BL/6 mice, icv infusion of NMU (8 microg x day(-1) x mouse(-1)) for 7 days decreased body weight and total energy intake compared with vehicle treatment. However, these parameters were unaffected by NMU treatment in lean male and female C57BL/6 mice fed a standard diet. In addition, female (but not male) NMUR2-null mice had increased body weight and body fat mass when fed a high-fat diet but lacked a clear body weight phenotype when fed a standard diet compared with wild-type littermates. Furthermore, female (but not male) NMUR2-null mice fed a high-fat diet were protected from central NMU-induced body weight loss compared with littermate wild-type mice. Thus, we provide the first evidence that long-term central NMU treatment reduces body weight, food intake, and adiposity and that central NMUR2 signaling is required for these effects in female but not male mice.
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| 6. |
- Herrgård, Markus J, et al.
(författare)
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A consensus yeast metabolic network reconstruction obtained from a community approach to systems biology
- 2008
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Ingår i: Nature Biotechnology. ; 26:10, s. 1155-1160
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Tidskriftsartikel (refereegranskat)abstract
- Genomic data allow the large-scale manual or semi-automated assembly of metabolic network reconstructions, which provide highly curated organism-specific knowledge bases. Although several genome-scale network reconstructions describe Saccharomyces cerevisiae metabolism, they differ in scope and content, and use different terminologies to describe the same chemical entities. This make comparisons between them difficult and underscores the desirability of a consolidated metabolic network that collects and formalizes the 'community knowledge' of yeast metabolism. We describe how we have produced a consensus metabolic network reconstruction for S. cerevisiae. In drafting it, we placed special emphasis on referencing molecules to persistent databases or using database-independent forms, such as SMILES or InChl strings, as this permits their chemical structure to be represented unambiguously and in a manner that permits automated reasoning. The reconstruction is readily available via a publicly accessible database and in the Systems Biology Markup Language (http://www.comp-sys-bio.org/yeastnet). It can be maintained as a resource that serves as a common denominator for studying the systems biology of yeast. Similar strategies should benefit communities studying genome-scale metabolic networks of other organisms.
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| 7. |
- Hjalmarson, Åke, et al.
(författare)
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Recent astronomy highlights from the Odin satellite
- 2005
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Ingår i: Advances in Space Research. - : Elsevier BV. - 0273-1177 .- 1879-1948. ; 36, s. 1031-1047
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Tidskriftsartikel (refereegranskat)abstract
- Astronomy highlights, mainly from the third year of Odin observations time shared 50/50% with aeronomy are presented: the very low O2 abundance limits achieved, the highly pressure broadened absorption lines of H2O, H218O, and CO (5 → 4) in the atmosphere of Mars, the high precision H2O and H218O observations of comets, the detections of NH3 and H2O around the C-rich star IRC+10216 (CW Leo) and of H2O around the O-rich star W Hya, NH3 and H2O observations of infall/outflow interactions, observations of H2O, H218O, H217O as well as NH3 and 15NH3 in multiple absorptions towards Sgr B2, and in emission towards Orion KL, the H2O detection of several new outflows in the DR21 W75S region. We also discuss the results of deconvolution of high S/N H2O, CO and 13CO (5 → 4) maps of the Orion KL region to 40″ resolution (the beam size of the Herschel telescope) and the first results from our ongoing “spectral scan” of Orion KL in bands around 555 and 570 GHz. Finally, a search for primordial molecules is presented.
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| 8. |
- Kuttippurath, J., et al.
(författare)
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Intercomparison of ozone profile measurements from ASUR, SCIAMACHY, MIPAS, OSIRIS, and SMR
- 2007
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Ingår i: Journal of Geophysical Research. - 0148-0227 .- 2156-2202. ; 112:D9
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Tidskriftsartikel (refereegranskat)abstract
- The airborne submillimeter radiometer ( ASUR) was deployed onboard the Falcon research aircraft during the scanning imaging absorption spectrometer for atmospheric cartography ( SCIAMACHY) validation and utilization experiment ( SCIAVALUE) and the European polar stratospheric cloud and lee wave experiment ( EuPLEx) campaigns. A large number of ozone profile measurements were performed over a latitude band spanning from 5 degrees S to 80 degrees N in September 2002 and February/March 2003 during the SCIAVALUE and around the northern polar latitudes in January/February 2003 during the EuPLEx. Both missions amassed an ample microwave ozone profile data set that is used to make quantitative comparisons with satellite measurements in order to assess the quality of the satellite retrievals. In this paper, the ASUR ozone profile measurements are compared with measurements from SCIAMACHY and Michelson interferometer for passive atmospheric sounding ( MIPAS) on Environmental Satellite and optical spectrograph and infrared imager system ( OSIRIS) and submillimeter radiometer ( SMR) on the Odin satellite. The cross comparisons with the criterion that the ASUR measurements are performed within +/- 1000 km and +/- 6 hrs of the satellite observations show a good agreement with all the four satellite sensors. The differences in data values are the following: -4 to +8% for ASUR-SCIAMACHY ( operational product, v2.1), within +/- 15% for ASUR-SCIAMACHY ( scientific product, v1.62), up to +6% for ASUR-MIPAS ( operational product v4.61) and ASUR- MIPAS ( scientific product v1-O(3)-1), up to 17% for ASUR- OSIRIS ( v012), and -6 to 17% for ASUR- SMR ( v222) between the 20- and 40- km altitude range depending on latitude. Thus, the intercomparisons provide important quantitative information about the quality of the satellite ozone profiles, which has to be considered when using the data for scientific analyses.
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| 9. |
- López-Nicolás, G, et al.
(författare)
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Nonholonomic epipolar visual servoing
- 2006
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Ingår i: 2006 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION (ICRA). - New York : IEEE. - 0780395050 ; , s. 2378-2384
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Konferensbidrag (refereegranskat)abstract
- A significant amount of work has been reported in the area of visual servoing during the last decade. However, most of the contributions are applied in cases of holonomic robots. More recently, the use of visual feedback for control of nonholonomic vehicles has been reported. Some of the examples are docking and parallel parking maneuvers of cars or vision-based stabilization of a mobile manipulator to a desired pose with respect to a target of interest. Still, many of the approaches are mostly interested in the control part of visual servoing loop considering very simple vision algorithms based on artificial markers. In this paper, we present an approach for nonholonomic visual servoing based on epipolar geometry. The method facilitates a classical teach-by-showing approach where a reference image is used to define the desired pose (position and orientation) of the robot. The major contribution of the paper is the design of the control law that considers nonholonomic constraints of the robot as well as the robust feature detection and matching process based on scale and rotation invariant image features. An extensive experimental evaluation has been performed in a realistic indoor setting and the results are summarized in the paper.
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| 10. |
- Lopez-Nicolas, G., et al.
(författare)
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Switching visual control based on epipoles for mobile robots
- 2008
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Ingår i: Robotics and Autonomous Systems. - AMSTERDAM : Elsevier. - 0921-8890 .- 1872-793X. ; 56:7, s. 592-603
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we present a Visual control approach consisting in a switching control scheme based on the epipolar geometry. The method facilitates a classical teach-by-showing approach where a reference image is used to control the robot to the desired pose (position and orientation). As a result of our proposal a mobile robot carries out a smooth trajectory towards the target and the epipolar geometry model is used through the whole motion. The control scheme developed considers the motion constraints of the mobile platform in a framework based on the epipolar geometry that does not rely on artificial markers or specific models of the environment. The proposed method is designed in order to cope with the degenerate estimation case of the epipolar geometry with short baseline. Experimental evaluation has been performed in realistic indoor and outdoor settings.
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