| 1. |
- Aad, G, et al.
(författare)
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- 2015
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swepub:Mat__t
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| 2. |
- Faatz, B., et al.
(författare)
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Simultaneous operation of two soft x-ray free-electron lasers driven by one linear accelerator
- 2016
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Ingår i: New Journal of Physics. - : IOP Publishing. - 1367-2630. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- Extreme-ultraviolet to x-ray free-electron lasers (FELs) in operation for scientific applications are up to now single-user facilities. While most FELs generate around 100 photon pulses per second, FLASH at DESY can deliver almost two orders of magnitude more pulses in this time span due to its superconducting accelerator technology. This makes the facility a prime candidate to realize the next step in FELs-dividing the electron pulse trains into several FEL lines and delivering photon pulses to several users at the same time. Hence, FLASH has been extended with a second undulator line and self-amplified spontaneous emission (SASE) is demonstrated in both FELs simultaneously. FLASH can now deliver MHz pulse trains to two user experiments in parallel with individually selected photon beam characteristics. First results of the capabilities of this extension are shown with emphasis on independent variation of wavelength, repetition rate, and photon pulse length.
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| 3. |
- Buunen, M, et al.
(författare)
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COLOR II. A randomized clinical trial comparing laparoscopic and open surgery for rectal cancer.
- 2009
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Ingår i: Danish medical bulletin. - 1603-9629 .- 0907-8916. ; 56:2, s. 89-91
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Laparoscopic resection of rectal cancer has been proven efficacious but morbidity and oncological outcome need to be investigated in a randomized clinical trial. Trial design: Non-inferiority randomized clinical trial. METHODS: The COLOR II trial is an ongoing international randomized clinical trial. Currently 27 hospitals from Europe, South Korea and Canada are including patients. The primary endpoint is loco-regional recurrence rate three years post-operatively. Secondary endpoints cover quality of life, overall and disease free survival, post-operative morbidity and health economy analysis. RESULTS: By July 2008, 27 hospitals from the Netherlands, Belgium, Germany, Sweden, Spain, Denmark, South Korea and Canada had included 739 patients. The intra-operative conversion rate in the laparoscopic group was 17%. Distribution of age, location of the tumor and radiotherapy were equal in both treatment groups. Most tumors are located in the mid-rectum (41%). CONCLUSION: Laparoscopic surgery in the treatment of rectal cancer is feasible. The results and safety of laparoscopic surgery in the treatment of rectal cancer remain unknown, but are subject of interim analysis within the COLOR II trial. Completion of inclusion is expected by the end of 2009. Trial registration: Clinicaltrials.gov, identifier: NCT00297791 (www.clinicaltrials.gov).
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| 4. |
- Ruppel, M. M., et al.
(författare)
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Organic Compounds, Radiocarbon, Trace Elements and Atmospheric Transport Illuminating Sources of Elemental Carbon in a 300-Year Svalbard Ice Core
- 2023
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Ingår i: Journal of Geophysical Research - Atmospheres. - 2169-897X .- 2169-8996. ; 128:16
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Tidskriftsartikel (refereegranskat)abstract
- Black carbon (BC) particles produced by incomplete combustion of biomass and fossil fuels warm the atmosphere and decrease the reflectivity of snow and ice, hastening their melt. Although the significance of BC in Arctic climate change is widely acknowledged, observations on its deposition and sources are few. We present BC source types in a 300-year (1700-2005) Svalbard ice core by analysis of particle-bound organic compounds, radiocarbon, and trace elements. According to the radiocarbon results, 58% of the deposited elemental carbon (EC, thermal-optical proxy of BC) is of non-fossil origin throughout the record, while the organic compounds suggest a higher percentage (68%). The contribution of fossil fuels to EC is suggested to have been elevated between 1860 and 1920, particularly based on the organics and trace element data. A second increase in fossil fuel sources seems to have occurred near the end of the record: according to radiocarbon measurements between 1960 and 1990, while the organics and trace element data suggest that the contribution of fossil fuels has increased since the 1970s to the end of the record, along with observed increasing EC deposition. Modeled atmospheric transport between 1948 and 2004 shows that increasing EC deposition observed at the glacier during that period can be associated with increased atmospheric transport from Far East Asia. Further observational BC source data are essential to help target climate change mitigation efforts. The combination of robust radiocarbon with organic compound analyses requiring low sample amounts seems a promising approach for comprehensive Arctic BC source apportionment.
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| 5. |
- Elsasser, M., et al.
(författare)
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Organic molecular markers and signature from wood combustion particles in winter ambient aerosols: aerosol mass spectrometer (AMS) and high time-resolved GC-MS measurements in Augsburg, Germany
- 2012
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Ingår i: Atmospheric Chemistry and Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 12:14, s. 6113-6128
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Tidskriftsartikel (refereegranskat)abstract
- The impact of wood combustion on ambient aerosols was investigated in Augsburg, Germany during a winter measurement campaign of a six-week period. Special attention was paid to the high time resolution observations of wood combustion with different mass spectrometric methods. Here we present and compare the results from an Aerodyne aerosol mass spectrometer (AMS) and gas chromatographic - mass spectrometric (GC-MS) analysed PM1 filters on an hourly basis. This includes source apportionment of the AMS derived organic matter (OM) using positive matrix factorisation (PMF) and analysis of levoglucosan as wood combustion marker, respectively. During the measurement period nitrate and OM mass are the main contributors to the defined submicron particle mass of AMS and Aethalometer with 28% and 35%, respectively. Wood combustion organic aerosol (WCOA) contributes to OM with 23% on average and 27% in the evening and night time. Conclusively, wood combustion has a strong influence on the organic matter and overall aerosol composition. Levoglucosan accounts for 14% of WCOA mass with a higher percentage in comparison to other studies. The ratio between the mass of levoglucosan and organic carbon amounts to 0.06. This study is unique in that it provides a one-hour time resolution comparison between the wood combustion results of the AMS and the GC-MS analysed filter method at a PM1 particle size range. The comparison of the concentration variation with time of the PMF WCOA factor, levoglucosan estimated by the AMS data and the levoglucosan measured by GC-MS is highly correlated (R-2 = 0.84), and a detailed discussion on the contributors to the wood combustion marker ion at mass-to-charge ratio 60 is given. At the end, both estimations, the WCOA factor and the levoglucosan concentration estimated by AMS data, allow to observe the variation with time of wood combustion emissions (gradient correlation with GC-MS levoglucosan of R-2 = 0.84). In the case of WCOA, it provides the estimated magnitude of wood combustion emission. Quantitative estimation of the levoglucosan concentration from the AMS data is problematic due to its overestimation in comparison to the levoglucosan measured by the GC-MS.
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