| 1. |
- Bargholtz, Chr., et al.
(författare)
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The WASA detector facility at CELSIUS
- 2008
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 594:3, s. 339-350
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Tidskriftsartikel (refereegranskat)abstract
- The WASA 4 pi multidetector system, aimed at investigating light meson production in light ion collisions and eta meson rare decays at the CELSIUS storage ring in Uppsala is presented. A unique feature of the system is the use of hydrogen pellets as internal targets for the first time. A detailed description of the design, together with the anticipated and achieved performance parameters are given. (C) 2008 Elsevier B.V. All rights reserved.
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| 2. |
- Pham, M. K., et al.
(författare)
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Certified reference material for radionuclides in fish flesh sample IAEA-414 (mixed fish from the Irish Sea and North Sea)
- 2006
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Ingår i: Proceedings of the 15th International Conference on Radionuclide Metrology and its Applications (Applied Radiation and Isotopes). - Amsterdam : Elsevier BV. - 0969-8043 .- 1872-9800. ; 64:10-11, s. 1253-1259
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Konferensbidrag (refereegranskat)abstract
- A certified reference material (CRM) for radionuclides in fish sample IAEA-414 (mixed fish from the Irish Sea and North Seas) is described and the results of the certification process are presented. Nine radionuclides (K-40, Cs-137, Th-232, U-234, U-235, U-238, Pu-238, Pu239+240 and Am-241) were certified for this material. Information on massic activities with 95% confidence intervals is given for six other radionuclides (Sr-90, Pb-210(Po-210), Ra-226, Pu-239, Pu-240 Pu-241). Less frequently reported radionuclides (Tc-99, I-129, Th-228, Th-230 and Np-217) and information on some activity and mass ratios are also included. The CRM can be used for quality assurance/quality control of the analysis of radionuclides in fish sample, for the development and validation of analytical methods and for training purposes. The material is available from IAEA, Vienna, in 100 g units.
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| 3. |
- Povinec, Pavel, et al.
(författare)
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Reference material for radionuclides in sediment. IAEA-384 (Fangataufa lagoon sediment).
- 2007
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Ingår i: Journal of Radioanalytical and Nuclear Chemistry. - Dordrecht : Springer. - 0236-5731 .- 1588-2780. ; 273:2, s. 383-393
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Tidskriftsartikel (refereegranskat)abstract
- A reference material designed for the determination of anthropogenic and natural radionuclides in sediment, IAEA-384 (Fangataufa Lagoon sediment), is described and the results of certification are presented. The material has been certified for 8 radionuclides (40K, 60Co, 155Eu, 230Th, 238U, 238Pu, 239+240Pu and 241Am). Information values are given for 12 radionuclides (90Sr, 137Cs, 210Pb (210Po), 226Ra, 228Ra, 232Th, 234U, 235U, 239Pu, 240Pu and 241Pu). Less reported radionuclides include 228Th, 236U, 239Np and 242Pu. The reference material may be used for quality management of radioanalytical laboratories engaged in the analysis of radionuclides in the environment, as well as for the development and validation of analytical methods and for training purposes. The material is available from IAEA in 100 g units.
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| 4. |
- Bargholtz, Chr., et al.
(författare)
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Measurement of the eta -> pi(+)pi(-)e(+)e(-) decay branching ratio
- 2007
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 644:5-6, s. 299-303
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Tidskriftsartikel (refereegranskat)abstract
- The reaction pd -> He-3 eta at threshold was used to provide a clean source of eta mesons for decay studies with the WASA detector at CELSIUS. The branching ratio of the decay eta -> pi(+)pi(-)e(+)e(-) is measured to be (4.3 +/- 1.3 +/- 0.4) x 10(-4).
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| 5. |
- Bashkanov, M., et al.
(författare)
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Double-Pionic Fusion of Nuclear Systems and the "ABC" Effect : Approaching a Puzzle by Exclusive and Kinematically Complete Measurements
- 2009
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 102:5, s. 052301-
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Tidskriftsartikel (refereegranskat)abstract
- The ABC effect-a puzzling low-mass enhancement in the pi pi invariant mass spectrum, first observed by Abashian, Booth, and Crowe-is well known from inclusive measurements of two-pion production in nuclear fusion reactions. Here we report on the first exclusive and kinematically complete measurements of the most basic double-pionic fusion reaction pn -> d pi(0)pi(0) at beam energies of 1.03 and 1.35 GeV. The measurements, which have been carried out at CELSIUS-WASA, reveal the ABC effect to be a (pi pi)(I=L=0) channel phenomenon associated with both a resonancelike energy dependence in the integral cross section and the formation of a Delta Delta system in the intermediate state. A corresponding simple s-channel resonance ansatz provides a surprisingly good description of the data.
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| 6. |
- Bashkanov, M., et al.
(författare)
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Measurement of the slope parameter for the η → 3π0 decay in the pp → ppη reaction
- 2007
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 76:4, s. 048201-
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Tidskriftsartikel (refereegranskat)abstract
- The CELSIUS-WASA setup is used to measure the 3π0 decay of η mesons produced in pp interactions with beam kinetic energies of 1.36 and 1.45 GeV. The efficiency-corrected Dalitz plot and density distributions for this decay are shown, together with a fit of the quadratic slope parameter α yielding α = −0.026 ± 0.010(stat) ± 0.010(syst). This value is compared to recent experimental results and theoretical predictions.
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| 7. |
- Berlowski, M., et al.
(författare)
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Measurement of eta meson decays into lepton-antilepton pairs
- 2008
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Ingår i: Physical Review D. Particles and fields. - : American Physical Society. - 0556-2821 .- 1089-4918. ; 77:3, s. 032004-
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Tidskriftsartikel (refereegranskat)abstract
- A search for rare lepton decays of the eta meson was performed using the WASA detector at CELSIUS. Two candidates for double Dalitz decay eta -> e(+)e(-)e(+)e(-) events are reported with a background of 1.3 +/- 0.2 events. This allows to set an upper limit to the branching ratio of 9.7x10(-5) (90% CL). The branching ratio for the decay eta -> e(+)e(-)gamma is determined to (7.8 +/- 0.5(stat)+/- 0.8(syst))x10(-3) in agreement with world average value. An upper limit (90% CL) for the branching ratio for the eta -> e(+)e(-) decay is 2.7x10(-5) and a limit for the sum of the eta ->mu(+)mu(-)mu(+)mu(-) and eta ->pi(+)pi(-)mu(+)mu(-) decays is 3.6x10(-4).
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| 8. |
- Bill-Axelson, Anna, et al.
(författare)
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Radical prostatectomy versus watchful waiting in localized prostate cancer : the Scandinavian prostate cancer group-4 randomized trial
- 2008
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Ingår i: Journal of the National Cancer Institute. - : Oxford University Press. - 0027-8874 .- 1460-2105. ; 100:16, s. 1144-1154
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The benefit of radical prostatectomy in patients with early prostate cancer has been assessed in only one randomized trial. In 2005, we reported that radical prostatectomy improved prostate cancer survival compared with watchful waiting after a median of 8.2 years of follow-up. We now report results after 3 more years of follow-up.METHODS: From October 1, 1989, through February 28, 1999, 695 men with clinically localized prostate cancer were randomly assigned to radical prostatectomy (n = 347) or watchful waiting (n = 348). Follow-up was complete through December 31, 2006, with histopathologic review and blinded evaluation of causes of death. Relative risks (RRs) were estimated using the Cox proportional hazards model. Statistical tests were two-sided.RESULTS: During a median of 10.8 years of follow-up (range = 3 weeks to 17.2 years), 137 men in the surgery group and 156 in the watchful waiting group died (P = .09). For 47 of the 347 men (13.5%) who were randomly assigned to surgery and 68 of the 348 men (19.5%) who were not, death was due to prostate cancer. The difference in cumulative incidence of death due to prostate cancer remained stable after about 10 years of follow-up. At 12 years, 12.5% of the surgery group and 17.9% of the watchful waiting group had died of prostate cancer (difference = 5.4%, 95% confidence interval [CI] = 0.2 to 11.1%), for a relative risk of 0.65 (95% CI = 0.45 to 0.94; P = .03). The difference in cumulative incidence of distant metastases did not increase beyond 10 years of follow-up. At 12 years, 19.3% of men in the surgery group and 26% of men in the watchful waiting group had been diagnosed with distant metastases (difference = 6.7%, 95% CI = 0.2 to 13.2%), for a relative risk of 0.65 (95% CI = 0.47 to 0.88; P = .006). Among men who underwent radical prostatectomy, those with extracapsular tumor growth had 14 times the risk of prostate cancer death as those without it (RR = 14.2, 95% CI = 3.3 to 61.8; P < .001).CONCLUSION: Radical prostatectomy reduces prostate cancer mortality and risk of metastases with little or no further increase in benefit 10 or more years after surgery.
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| 9. |
- Davidsson, Kent, 1967, et al.
(författare)
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Potassium, chlorine, and sulfur in ash, particles, deposits, and corrosion during wood combustion in a circulating fluidized-bed boiler
- 2007
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Ingår i: Energy & Fuels. - : American Chemical Society (ACS). - 1520-5029 .- 0887-0624. ; 21:1, s. 71-81
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Tidskriftsartikel (refereegranskat)abstract
- The effect of the addition of chlorine and/or sulfur to the fuel on fly ash composition, deposit formation, and superheater corrosion has been studied during biomass combustion in a circulating fluidized-bed boiler. The chlorine (HCl (aq)) and sulfur (SO2 (g)) were added in proportions of relevance for the potassium chemistry. The composition of the bottom and the fly ashes was analyzed. Gas and particle measurements were performed downstream of the cyclone before the convection pass and the flue gas composition was recorded in the stack with a series of standard instruments and an FTIR analyzer. At the position downstream of the cyclone, a deposit probe was situated, simulating a superheater tube. Deposits on the probe and initial corrosion were examined. It is concluded that addition of sulfur and chlorine increases the formation of submicron particles leading to deposition of potassium sulfate and chloride. The results compare well with earlier work based on laboratory-scale experiments concerning effects of chlorine and sulfur on potassium chemistry.
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| 10. |
- Jansen, N. W. D., et al.
(författare)
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Digital scoring of haemophilic arthropathy using radiographs is feasible
- 2008
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Ingår i: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 14:5, s. 999-1006
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Tidskriftsartikel (refereegranskat)abstract
- Radiographs are important tools to evaluate structural changes in many Joint diseases. In the case of haemophilic arthropathy (HA), the Pettersson score is widely used. The rising of digital radiography enables evaluation of these changes in a more quantitative and detailed manner, potentially improving diagnosis and follow-up. The aim of this study was to evaluate whether digital image analysis ill the case of HA is feasible, using a presently available method for radiographic changes in knee osteoarthritis (OA), knee image digital analysis (KIDA). Sixty-two knee radiographs were scored according to Pettersson and with KIDA, each by two independent observers. Inter-observer variation and correlations between the two scoring methods were determined. The inter-observer variation was smaller for KIDA than for Pettersson and for KIDA not significantly different from evaluation of OA joints. Good correlations were found for the two methods where comparison of parameters was appropriate. Importantly, for each of the parameters within one point in the ordinal Pettersson score, a large window still existed in the continuous KIDA grading. Digital analysis of radiographs to quantify joint damage in HA is feasible. The use of continuous variables, as used in a digital method Such as KIDA has the advantage that it enables objective and much more sensitive detection of small changes than by use of an ordinal analogue method Such as the Pettersson score. Based oil the present results, it would be worthwhile to adapt the KIDA method for the specific characteristics of HA and to extend the method to elbow and ankle radiographs.
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