| 1. |
- Adliene, Diana, et al.
(author)
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Assessment of the environmental contamination with long-lived radionuclides around an operating RBMK reactor station
- 2006
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In: Journal of Environmental Radioactivity. - : Elsevier BV. - 1879-1700 .- 0265-931X. ; 90:1, s. 68-77
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Journal article (peer-reviewed)abstract
- The presence of man-made gamma emitting radionuclides in the region within 32 km radius of the Ignalina NPP/Lithuania has been investigated during the period 2001-2004, prior to the closure of the first 4 the two operating RBMK 1500-type reactors. Gamma spectrometric measurements of various terrestrial and aquatic plants as well as of soil samples showed moderate environmental contamination with the fission product Cs-137 and with the neutron activation products Co-60 and Mn-54. Traces of the activation products Zn-65 and Ag-110m were found in the nearest vicinity of the NPP. Activity concentrations were inhomogeneously distributed in the area of interest. Moss and algae samples showed the highest uptake of radionuclides. In addition to the gamma spectrometric measurements, the levels of C-14 were determined in the same bio-indicator samples using accelerator mass spectrometry. (c) 2006 Elsevier Ltd. All rights reserved.
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| 2. |
- Adolphi, Florian, et al.
(author)
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Intercomparison of C-14 Dating of Wood Samples at Lund University and Eth-Zurich Ams Facilities: Extraction, Graphitization, and Measurement
- 2013
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In: Radiocarbon. - 0033-8222. ; 55:2-3, s. 391-400
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Journal article (peer-reviewed)abstract
- We conducted an interlaboratory comparison between our radiocarbon-related research group at Lund University and the established ETH-Zurich facility to test the quality of the results obtained in Lund and to identify sources of potential background differences and scatter. We did find differences between the 2 laboratories in the contributions of chemical preparation, graphitization, and measurements to the overall background. The resulting overall background is, however, almost similar. Multiple measurements on 2 wood samples of known calendar age yield consistent and accurate C-14 ages in both laboratories. However, one of our known samples indicates that IntCal09 is similar to 38 +/- 16 C-14 BP too young at 7020 calendar yr BP, which is consistent with one of the raw data sets contributing to IntCal09. Overall, our results show that a systematic approach to compare the different steps involved in C-14 age determination is a useful exercise to pinpoint targets for improvement of lab routines and assess interlaboratory differences. These effects do not necessarily become apparent when comparing C-14 measurements that integrate over the whole process of preparation and measurement of different laboratories.
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| 3. |
- Alexandrescu, E, et al.
(author)
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Os fossils humains des grottes Muierii et Cioclovina, Roumanie
- 2010
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In: L'Anthropologie. - : Elsevier BV. - 0003-5521. ; 114:3, s. 341-353
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Journal article (peer-reviewed)abstract
- This paper presents the cultural and archaeological context of the human fossil bones from Muierii Cave, dated by us to the age of 30 150 ± 800 14C years BP (Before Present) or 34 810 ± 927 cal years BP (calibrated years Before Present), and from Cioclovina Cave, dated to the age of 29 000 ± 700 14C years BP or 33 540 ± 832 cal years BP, in the Southern Carpathians. These are among the most ancient dated human fossil remains from Central and South-Eastern Europe and are described in conjunction with other sites with Mousterian assemblages of the recent Neanderthal population, and sites with Aurignacian assemblage of early modern humans, from Romanian region, for the interval of time 34,000–26,000, the transitional period from the Middle Paleolithic to the Upper Paleolithic.
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| 4. |
- Berglund, Björn, et al.
(author)
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Early Holocene history of the Baltic Sea, as reflected in coastal sediments in Blekinge, southeastern Sweden
- 2005
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In: Quaternary International. - : Elsevier BV. - 1873-4553 .- 1040-6182. ; 130:1, s. 111-139
-
Journal article (peer-reviewed)abstract
- Integrated palaeoecological studies of two fiord sediment sequences in the province of Blekinge, SE Sweden, covering the time span 11,000-5000 cal BP, reveal the timing and the environment for the Ancylus Lake/Littorina Sea transition 9800-8500 cal BP. The first ingression of saline water into the Baltic Sea through the Danish Straits occurred earlier than formerly assumed. New evidence, particularly mineral magnetic and palaeobotanical analyses, demonstrate that on the general trend of the eustatically caused Littorina transgression several minor fluctuations of the water level can be identified between 8500 and 5000 cal years BP. A distinct regression phase around 8 100 cal BP is correlated with the Greenland ice-core cold event dated to 8200 ice-core years BP. This is described as a regional climatic catastrophe for the Baltic Sea region. The coastal stratigraphy is compared with the offshore stratigraphy earlier studied. A tentative shore displacement curve for Early and Middle Holocene is presented.
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| 5. |
- Björck, Svante, et al.
(author)
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Consistently large marine reservoir ages in the Norwegian Sea during the Last Deglaciation
- 2003
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In: Quaternary Science Reviews. - 0277-3791. ; 22:5-7, s. 429-435
-
Journal article (peer-reviewed)abstract
- With the exception of the GS-1/Younger Dryas cold period marine reservoir ages for the Last Deglaciation in the North Atlantic-Norwegian Sea are generally assumed to have been around 400-500 radiocarbon years in magnitude (Earth Planet. Sci. Lett. 126 (1994) 275; Radiocarbon 37 (1995) 53; Quat. Res. 52 (1999) 104; Nature 412 (2001) 724). By comparing the climate records obtained from the GRIP ice-core (Nature 359 (1992) 311; J. Quat. Sci. 13(4) (1998) 283) and from North Atlantic/Norwegian Sea cores (Quat. Res. 52 (1999) 104; Geology 23 (12) (1995) 1059; Nature 356 (1991) 757; Nature 356 (1992) 757; Paleoceanography 3(1) (1988) 1; Nature 343 (1990) 612; Earth Planet. Sci. Lett. 126 (1994) 275), with radiocarbon-dated European continental records, we show that marine reservoir ages in the Norwegian Sea were of the order of 1000 C-14 yr, including large uncertainties. This approach rests on the reasonable assumption that climate changes throughout the NE Atlantic and Europe were more or less synchronous at the centennial scale. Fairly large variations in reservoir ages over time may have been caused by changing atmospheric C-14 content. The results indicate that detailed land-sea correlations for the North Atlantic during the Last Deglaciation are not feasible using radiocarbon dating alone. (C) 2003 Elsevier Science Ltd. All rights reserved.
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| 6. |
- Dias, C M, et al.
(author)
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14CO2 dispersion around two PWR nuclear power plants in Brazil.
- 2009
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In: Journal of Environmental Radioactivity. - : Elsevier BV. - 1879-1700 .- 0265-931X. ; 100:7, s. 574-580
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Journal article (peer-reviewed)abstract
- Atmospheric air samples were taken within 3 km from power plants encompassing five different distances and wind directions. Samples were taken between 2002 and 2005 aiming to evaluate the environmental C-14 enrichment due to the operation of Brazilian nuclear power plants. The sampling system consisted of a pump connected to a trapping column filled with a 3 M NaOH solution. The trapped C-14 by using a single stage accelerator mass spectrometry (SSAMS). CO2 was analyzed for All sampling sites revealed measurable C-14 excess values. The maximum excesses were of 15 and 14 mBq/m(3) for sampling sites placed at NE of the power plants, which is the main wind direction in the area. The mean excesses values were 12 mBq/m(3) to the NE direction, 8 mBq/m to the E, 10 mBq/m to the N, 8 mBq/m(3) to the WNW and 7 mBq/m(3) to the W direction (increasing distances from NE to W). Compared to other Light Water Reactors (LWR) data, these means' values are significantly higher than the average worldwide reported value of 3 mBq/m(3). Available data indicate that the observed values are not related to C-14 emission by the power plants vent stack. Other factors, such as topography, seem to have an important role because it affects wind dispersion thus favoring C-14 accumulation in the sampled area. Moreover, the high elevations around the power plants enhance the chances to measure high values of C-14 since the plume can be intercepted before it is drawn to the ground. Modeling of the plume has shown that its dispersion does not follow a Gaussian model and that agreement between atmospheric CO2 and vegetation C-14 activities occurs only for sampling sites placed at NE of the power plants. (c) 2009 Elsevier Ltd. All rights reserved.
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| 7. |
- Dias, Cintia Melazo, et al.
(author)
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C-14, delta C-13 and total C content in soils around a Brazilian PWR nuclear power plant
- 2009
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In: Journal of Environmental Radioactivity. - : Elsevier BV. - 1879-1700 .- 0265-931X. ; 100:4, s. 348-353
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Journal article (peer-reviewed)abstract
- Nuclear power plants release C-14 during routine operation mainly as airborne gaseous effluents. Because of the long half-life (5730 years) and biological importance of this radionuclide (it is incorporated in plant tissue by photosynthesis), several countries have monitoring programs in order to quantify and control these emissions. This paper compares the activity of C-14 in soils taken within I km from a Brazilian nuclear power plant with soils taken within a reference area located 50 km away from the reactor site. Analyses of total carbon, delta C-13 and Cs-137 were also performed in order to understand the local soil dynamics. Except for one of the profiles, the isotopic composition of soil organic carbon reflected the actual forest vegetation present in both areas. The Cs-137 data show that the soils from the base of hills are probably allocthonous. The C-14 Measurements showed that there is no accumulation due to the operation of the nuclear facility, although excess C-14 Was found in the litter taken in the area close to power plant. This indicates that the anthropogenic signal observed in the litter fall has not been transferred yet to the soil. This study is part of an extensive research programme in which other samples including air, vegetation and gaseous effluents (taken in the vent stack of the Brazilian nuclear power reactors Angra I and II) were also analyzed. The present paper aimed to evaluate how C-14 emissions from the nuclear power plant are transferred and stored by soils present in the Surroundings of the reactor site. This is the first study concerning anthropogenic 14C in soils in Brazil. (9) 2009 Elsevier Ltd. All rights reserved.
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| 8. |
- Edsfeldt, Andreas, et al.
(author)
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Human Atherosclerotic Plaque Progression Is Dependent on Apoptosis According to Bomb-Pulse 14C Dating
- 2021
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In: JACC: Basic to Translational Science. - : Elsevier BV. - 2452-302X. ; 6:9-10, s. 734-745
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Journal article (peer-reviewed)abstract
- Individuals with rapidly progressing atherosclerotic plaques are at higher risk of experiencing acute complications. Currently, we lack knowledge regarding factors in human plaque that cause rapid progression. Using the 14C bomb-pulse dating method, we assessed the physical age of atherosclerotic plaques and which biological processes were associated with rapidly progressing plaques. Interestingly, increased apoptosis was the main component associated with a young physical plaque age, reflecting rapid plaque progression. Our findings in combination with recent advances in imaging techniques could guide future diagnostic imaging strategies to identify rapidly progressing plaques or therapeutic targets, halting plaque progression.
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| 9. |
- Eriksson Stenström, Kristina, et al.
(author)
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Environmental levels of radiocarbon in Lund, Sweden, prior to the start of the European Spallation Source
- 2022
-
In: Radiocarbon. - 0033-8222. ; 64:1, s. 51-56
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Journal article (peer-reviewed)abstract
- The European Spallation Source (ESS) is a neutron-based research facility under construction in Lund in southern Sweden. The spallation reactions will generate not only the desired neutrons, but also many radioactive byproducts, including 14C. As part of the licensing process, and as recommended by the IAEA, various preoperational studies are being carried out, including mapping the “zero-point” radiation environment around the site. As the city of Lund hosts several facilities using 14C-labeled substances, and since temporary and local 14C contamination have been observed in the past, 14C mapping is an important part of these baseline assessments. We here present a summary of 14C levels in various terrestrial environmental samples in Lund and in southern Sweden during the years 2012 to 2020. These environmental F14C do not display significantly elevated levels compared to sites located remote from Lund. We also describe a local 14C contamination event that was detected at the Lund Radiocarbon Dating Laboratory in 2009. Horse-chestnut leaves collected close to the laboratory exhibited F14C values of up to ∼25% above the clean air background. Elevated values of F14C were also found in a short tree-ring series, especially in 2007. The source of this contamination was identified and successfully removed.
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| 10. |
- Faarinen, Mikko, et al.
(author)
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Al-26 at the AMS facility in Lund
- 2004
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In: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 223-24, s. 130-134
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Journal article (peer-reviewed)abstract
- To broaden the AMS programme in Lund by including Al studies, a new injector has been installed and tested at the 3 MV Pelletron accelerator. Detailed optical calculations have been performed to obtain maximum mass and energy resolution. The design of the injector, the improvement in the resolution compared to the old injector, as well as preliminary tests with a Al-26-beam, are presented. By using accelerator mass spectrometry (AMS) to measure the long-lived aluminium isotope Al-26 it has become possible to study the uptake, distribution and retention of aluminium in biological system under physiologically realistic conditions. Results from a pilot project on Al-26 in wheat plants are presented.
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| 11. |
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| 12. |
- Georgiadou, Elisavet, et al.
(author)
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Bomb-pulse (14)C analysis combined with (13)C and (15)N measurements in blood serum from residents of Malmö, Sweden.
- 2013
-
In: Radiation and Environmental Biophysics. - : Springer Science and Business Media LLC. - 1432-2099 .- 0301-634X. ; 52:2, s. 175-187
-
Research review (peer-reviewed)abstract
- The (14)C content of 60 human blood serum samples from residents of Malmö (Sweden) in 1978, obtained from a biobank, has been measured to estimate the accuracy of (14)C bomb-pulse dating. The difference between the date estimated using the Calibomb software and sampling date varied between -3 ± 0.4 and +0.2 ± 0.5 years. The average age deviation of all samples was -1.5 ± 0.7 years, with the delay between production and consumption of foodstuffs being probably the dominating cause. The potential influence of food habits on the (14)C date has been evaluated using stable isotope δ(13)C and δ(15)N analysis and information about the dietary habits of the investigated individuals. Although the group consisting of lacto-ovo vegetarians and vegans (pooled group) was not completely separated from the omnivores in a stable isotopic trophic level diagram, this analysis proved to add valuable information on probable dietary habits. The age deviation of the sampling date from the respective Calibomb date was found strongly correlated with the δ(13)C values, probably due to influence from marine diet components. For the omnivore individuals, there were indications of seasonal effects on δ(13)C and the age deviation. No significant correlation was found between the age deviation and the δ(15)N values of any dietary group. No influence of sex or year of birth was found on neither the (14)C nor the δ(13)C and δ(15)N values of the serum samples. The data were also divided into two groups (omnivores and pooled group), based on the level of δ(15)N in the samples. The consumption of high δ(15)N-valued fish and birds can be responsible for this clustering.
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| 13. |
- Georgiadou, Elisavet, et al.
(author)
-
Bomb-pulse 14C analysis combined with 13C and 15N measurements in blood serum from residents of Malmö, Sweden
- 2013
-
Conference paper (peer-reviewed)abstract
- The 14C content of 60 human blood serum samples from residents of Malmö (Sweden) in 1978, obtained from a biobank, has been measured to estimate the accuracy of 14C bomb-pulse dating. The difference between the date estimated by using the Calibomb software and sampling date varied between -3±0.4 and +0.2±0.5 years. The average age deviation of all samples was -1.5±0.7 years, with the delay between production and consumption of foodstuffs being probably the dominating cause. The potential influence of food habits on the 14C date has been evaluated using stable isotope δ13C and δ15N analysis and information about the dietary habits of the investigated individuals. Although the group consisting of lacto-ovo vegetarians and vegans (pooled group) was not completely separated from the omnivores in a stable isotopic trophic level diagram, this analysis proved to add valuable information on probable dietary habits. The age deviation of the sampling date from the respective Calibomb date was found strongly correlated with the δ13C values, probably due to influence from marine diet components. For the omnivore individuals, there were indications of seasonal effects on δ13C and the age deviation. No significant correlation was found between the age deviation and the δ15N values of any dietary group. No influence of sex or year of birth was found on neither the 14C nor the δ13C and δ15N values of the serum samples. The data were also divided into two groups (omnivores and pooled group), based on the level of δ15N in the samples. The consumption of high δ15N-valued fish and birds can be responsible for this clustering.
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| 14. |
- Georgiadou, Elisavet, et al.
(author)
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Potential Influence of Diet on Bomb-Pulse Dating of Human Plaque Samples
- 2013
-
In: Radiocarbon. - : Cambridge University Press (CUP). - 0033-8222. ; 55:2-3, s. 874-884
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Journal article (peer-reviewed)abstract
- The radiocarbon concentration of different atherosclerotic plaque fragments obtained from 20 patients in Portugal, operated in 2000-2001, has been measured in order to define the year of plaque formation. A difference of 1.8-15 yr was observed, with the mean and median both 9 yr, between the bomb-pulse date estimated with the CALIBomb software and the operation date. Stable isotope (delta C-13 and delta N-15) analysis was also performed and provides insight to the diet of the subjects. The wide range of measured stable isotope values could indicate that the subjects' diet varied, including an abundance of marine foodstuffs. It could also mean a different isotope fractionation process for the different plaque fragments (cap, core, interface to media) and a possible difference in tissues in which the various fragments are formed. Analysis of delta C-13 and delta N-15 values of each patient separately revealed subjects considered more influenced by marine foodstuffs consumption.
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| 15. |
- Goncalves, Isabel, et al.
(author)
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Dating Components of Human Atherosclerotic Plaques
- 2010
-
In: Circulation Research. - 1524-4571. ; 106:6, s. 1174-1177
-
Journal article (peer-reviewed)abstract
- Rationale: Atherosclerotic plaques that give rise to acute clinical symptoms are typically characterized by degradation of the connective tissue and plaque rupture. Experimental studies have shown that mechanisms to repair vulnerable lesions exist, but the rate of remodeling of human plaque tissue has not been studied. Objective: In the present study, we determined the biological age of different components of advanced human atherosclerotic plaques by analyzing tissue levels of (14)C released into the atmosphere during the nuclear weapons tests in the late 1950s and early 1960s. Methods and Results: Atherosclerotic plaques were obtained from 10 patients (age 46 to 80 years) undergoing carotid surgery. Different regions of the plaques were dissected and analyzed for (14)C content using accelerator mass spectrometry. At the time of surgery, the mean biological age of the cap region was 6.4+/-3.2 years, which was significantly lower than that of the shoulder region (12.9+/-3.0 years, P<0.01), the interface toward the media (12.4+/-3.3 years, P<0.01), and the core (9.8+/-4.5 years, P<0.05). Analysis of proliferative activity and rate of apoptosis showed no signs of increased cellular turnover in the cap, suggesting that the lower (14)C content reflected a more recent time of formation. Conclusions: These results show that the turnover time of human plaque tissue is very long and may explain why regression of atherosclerotic plaque size rarely is observed in cardiovascular intervention trials.
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| 16. |
- Goncalves, Isabel, et al.
(author)
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Direct association between diet and the stability of human atherosclerotic plaque.
- 2015
-
In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 5
-
Journal article (peer-reviewed)abstract
- Mediterranean diet has been suggested to explain why coronary heart disease mortality is lower in southern than northern Europe. Dietary habits can be revealed by isotope ratio mass spectrometry (IRMS) measurement of carbon (δ(13)C) and nitrogen (δ(15)N) in biological tissues. To study if diet is associated with human plaque stability, atherosclerotic plaques from carotid endarterectomy on 56 patients (21 Portuguese and 35 Swedish) were analysed by IRMS and histology. Plaque components affecting rupture risk were measured. Swedish plaques had more apoptosis, lipids and larger cores, as well as fewer proliferating cells and SMC than the Portuguese, conferring the Swedish a more rupture-prone phenotype. Portuguese plaques contained higher δ(13)C and δ(15)N than the Swedish, indicating that Portuguese plaques were more often derived from marine food. Plaque δ(13)C correlated with SMC and proliferating cells, and inversely with lipids, core size, apoptosis. Plaque δ(15)N correlated with SMC and inversely with lipids, core size and apoptosis. This is the first observational study showing that diet is reflected in plaque components associated with its vulnerability. The Portuguese plaques composition is consistent with an increased marine food intake and those plaques are more stable than those from Swedish patients. Marine-derived food is associated with plaque stability.
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| 17. |
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| 18. |
- Gunnarsson, Mikael, et al.
(author)
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Long-term biokinetics and radiation exposure of patients undergoing 14C-glycocholic acid and 14C-xylose breath tests.
- 2007
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In: Cancer Biotherapy & Radiopharmaceuticals. - : Mary Ann Liebert Inc. - 1557-8852 .- 1084-9785. ; 22:6, s. 762-771
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Journal article (peer-reviewed)abstract
- The (14)C-glycocholic acid and (14)C-xylose breath tests are clinically used for the diagnosis of intestinal diseases, such as bacterial overgrowth in the small intestine. The two tests have in earlier studies been thoroughly evaluated regarding their clinical value, but due to the long physical half-life of (14)C and the limited biokinetic and dosimetric data, which are available for humans, several hospitals have been restrictive in their use. The aim of this study was to investigate the long-term biokinetics and dosimetry of the two (14)C compounds in patients and volunteers, using the highly sensitive accelerator mass spectrometry (AMS) technique. Eighteen (18) subjects were included, 9 for each compound. The (14)C content in samples from exhaled air, urine, and, for some subjects, also feces were analyzed with both liquid scintillation counting (LSC) and AMS. The results from the glycocholic acid study showed that, up to 1 year after the administration, 67%+/-6% (mean+/-standard deviation) of the administered activity was recovered in exhaled air, 2.4%+/-0.4% was found in urine, and 7.6% (1 subject) in feces. In the xylose study, the major part was found in the urine (66%+/-2%). A significant part was exhaled (28%+/-5%), and the result from an initial 72-hour stool collection from 2 of the subjects showed that the excretion by feces was insignificant. The absorbed dose to various organs and tissues and the effective dose were calculated by using biokinetic models, based on a combination of experimental data from the present study and from earlier reports. In the glycocholic acid study, the highest absorbed dose was received by the colon (1.2 mGy/MBq). In the xylose study, the adipose tissue received 0.8 mGy/MBq. The effective dose was estimated to 0.5 (glycocholic acid) and 0.07 mSv/MBq (xylose). Thus, from a radiation protection point of view, we see no need for restrictions in using the two (14)C-labeled radiopharmaceuticals on adults with the activities normally administered (0.07-0.4 MBq).
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| 19. |
- Gunnarsson, Mikael, et al.
(author)
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No radiation protection reasons for restrictions on C-14 urea breath tests in children.
- 2002
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In: British Journal of Radiology. - : British Institute of Radiology. - 1748-880X .- 0007-1285. ; 75:900, s. 982-986
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Journal article (peer-reviewed)abstract
- Traditional 14C urea breath tests are normally not used for younger children because the radiation exposure is unknown. High sensitivity accelerator mass spectrometry and an ultra-low amount (440 Bq) of 14C urea were therefore used both to diagnose Helicobacter pylori (HP) infection in seven children, aged 3–6 years, and to make radiation dose estimates. The activity used was 125 times lower than the amount normally used for older children and 250 times lower than that used for adults. Results were compared with previously reported biokinetic and dosimetric data for adults and older children aged 7–14 years. 14C activity concentrations in urine and exhaled air per unit administered activity for younger children (3–6 years) correspond well with those for older children (7–14 years). For a child aged 3–6 years who is HP negative, the urinary bladder wall receives the highest absorbed dose, 0.3 mGy MBq-1. The effective dose is 0.1 mSv MBq-1 for the 3-year-old child and 0.07 mSv MBq-1 for the 6-year-old child. For two children, the 10 min and 20 min post-14C administration samples of exhaled air showed a significantly higher amount of 14C activity than for the rest of the children, that is 6% and 19% of administered activity exhaled per hour compared with 0.3–0.9% (mean 0.5%) of administered activity exhaled per hour indicating that these two children that is were HP positive. For a 3-year-old HP positive child, absorbed dose to the urinary bladder wall was 0.3 mGy MBq-1 and effective dose per unit of administered activity was 0.4 mSv MBq-1. Using 55 kBq, which is a normal amount for older children when liquid scintillation counters are used for measurement, the effective dose will be approximately 6 µSv to a 3-year-old HP negative child and 20 µSv to a HP positive child. Thus there is no reason for restrictions on performing a normal 14C urea breath test, even on young children.
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| 20. |
- Hanslik, Daniela, et al.
(author)
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A high resolution Late Glacial and Postglacial record from the central Lomonosov Ridge, Arctic Ocean
- 2008
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In: Second Conference on Arctic Palaeoclimate and its Extremes (APEX).
-
Conference paper (other academic/artistic)abstract
- Core HLY0503-18TC used for this study was taken during the 2005 Healy-Oden Trans-Arctic Expedition (HOTRAX) on the central Lomonosov Ridge. The coring site is located in a local “Intra Basin”, a >1000 m deep depression in the ridge morphology, where sedimentation appears to be focused and accumulation rates, thus, are higher (Björk et al., 2007). The uppermost 70 cm of core HLY0503-18TC contains high abundances of well preserved planktonic and benthic foraminifera and calcareous nannofossils. The planktonic foraminifera assemblage in the >125 μm size fraction is monospecific and consists of Neogloboquadrina pachyderma, of which >95% are of the left-coiling variety. Stable isotope measurements of the >150 μm size fraction on N. pachyderma (s) show a distinct δ13C minimum at 35-40 cm depth. Similar changes in δ13C in previous studies have been associated with a major melt water anomaly at the beginning of Termination I (Nørgaard-Pedersen et al., 1998; Stein et al., 1994). We also see other signs for a significant shift at this depth, such as low foraminifera abundance and a change in the coccolith assemblage (Fornaciari et al., 2006). To establish an age model for core HLY0503-18TC radiocarbon dating was performed on nine very small planktonic and benthic foraminifera samples at Lund University Radiocarbon Dating Laboratory. The results indicate Holocene/Late Glacial ages for the samples in the upper half of the core. The oldest non-infinite 14C-dating provided an age of ~14 cal ka BP on a sample at 32 cm depth (Marine04 calibration data set). However, the highly incoherent ages of planktonic and benthic foraminifer at 12 cm depth imply high reservoir ages for at least deeper Arctic waters, showing that caution is needed when a 14C based chronology is established on Arctic marine sediments. All 14C measurements below 42 cm core depth yielded infinite ages (>44 ka). This large shift of more than 30 kyr over a few centimeters suggests a hiatus, either in form of no/low sedimentation or erosion due to changes in the paths or strength of the bottom currents. The abundance of foraminifera and the nannofossil composition of the sediments between 40 and 70 cm core depth suggests that this part of the core belongs to either marine isotope stage 3 or 5 (Fornaciari et al., 2006). This implies that at least entire MIS 2 may be missing in the core.
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| 21. |
- Hanslik, Daniela, et al.
(author)
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Quaternary Arctic Ocean sea ice variations and deep water isolation times
- 2010
-
In: Quaternary Science Reviews. - : Elsevier BV. - 0277-3791 .- 1873-457X. ; 29:25-26, s. 3430-3441
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Journal article (peer-reviewed)abstract
- A short sediment core retrieved from a local depression forming an intra basin on the Lomonosov Ridge during the Healy-Oden Trans-Arctic Expedition 2005 (HOTRAX) contains a record of the Marine Isotope Stages (MIS) 1-3 showing exceptionally high abundances of calcareous microfossils during parts of MIS 3. Based on radiocarbon dating, linear sedimentation rates of 7-9 cm/ka persist during the last deglaciation. Last Glacial Maximum (LGM) is partly characterized by a hiatus. Planktic foraminiferal abundance variations of Neogloboquadrina pachyderma sinistral and calcareous nannofossils reflect changes in Arctic Ocean summer sea ice coverage and probably inflow of subpolar North Atlantic water. Marine reservoir ages of 1400 years or more, at least during the last deglaciation, seem plausible from calibration of the radiocarbon ages using modeled reservoir corrections from previous studies in combination with the microfossil abundance record of the studied core. Paired benthic-planktic radiocarbon dated foraminiferal samples indicate a slow decrease in age difference between surface and bottom waters from the Late Glacial to the Holocene, suggesting circulation and ventilation changes.
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| 22. |
- Hanslik, Daniela, et al.
(author)
-
Quaternary Arctic Ocean sea ice variations and radiocarbon reservoir age corrections
- 2010
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In: Quaternary Science Reviews. - : Elsevier BV. - 0277-3791. ; 29:25-26, s. 3430-3441
-
Journal article (peer-reviewed)abstract
- A short sediment core from a local depression forming an intra basin on the Lomonosov Ridge, was retrieved during the Healy-Oden Trans-Arctic Expedition 2005 (HOTRAX). It contains a record of the Marine Isotope Stages (MIS) 1-3 showing exceptionally high abundances of calcareous microfossils during parts of MIS 3. Based on radiocarbon dating, linear sedimentation rates of 7-9 cm/ka persist during the last deglaciation. The Last Glacial Maximum (LGM) is partly characterized by a hiatus. Planktic foraminiferal abundance variations of Neogloboquadrina pachyderma sinistral and calcareous nannofossils reflect changes in Arctic Ocean summer sea ice coverage and probably inflow of subpolar North Atlantic water. Calibration of the radiocarbon ages, using modeled reservoir corrections from previous studies and the microfossil abundance record of the studied core, results in marine reservoir ages of 1400 years or more, at least during the last deglaciation. Paired benthic-planktic radiocarbon dated foraminiferal samples indicate a slow decrease in age difference between surface and bottom waters from the Lateglacial to the Holocene, suggesting circulation and ventilation changes. (C) 2010 Elsevier Ltd. All rights reserved.
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| 23. |
- Hanslik, Daniela, et al.
(author)
-
Radiocarbon calibration of a high resolution core from the Central Arctic Ocean
- 2008
-
In: EOS Transactions: American Geophysical Union. ; , s. PP51A-1483
-
Conference paper (other academic/artistic)abstract
- The big challenge in calibrating radiocarbon dates to calendar years for Arctic Ocean deep sea sediments is to estimate the marine reservoir age of the water masses. Most sediment cores from the central Arctic Ocean have a low resolution and the preserved record for the last 25 ka is in the order of 10-20 cm. Therefore, most AMS 14C dating results are presented either uncalibrated or corrected. The used reservoir values often vary between 400 and 550 years, close to the global mean ocean reservoir age, since all available regional reservoir differences (ΔR) are from coastal areas around the Arctic Ocean. Our study presents 14C ages and calibration attempts with different modelled reservoir ages from a high resolution record of Holocene and Late Glacial sediments from the Lomonosov Ridge. During the 2005 Healy-Oden Trans-Arctic Expedition (HOTRAX) an area of the central Lomonosov Ridge, between about 88°15’–89°N and 140°–180°E, was cored where a >1000 m deep depression characterizes the ridge morphology. Calcareous nannofossils (Fornaciari and Backman in prep.) and foraminifera analyzed in the upper 70 cm of core HLY0503-18TC show a sequence of the last ~130 ka. The chronology has been established through the nannofossil record in the lower 30 cm (Fornaciari and Backman in prep.) and 14C dating in the upper 40 cm. The data indicate very high accumulation rates during the Late Glacial of ~10 cm/ka, and times of extremely low to no accumulation during the Last Glacial Maximum, MIS 4 and parts of MIS 5. In addition, 14C dating on benthic and planktonic foraminifera from the same depth in the sediment core reveals age differences between surface and deep water masses. The age difference of such benthic-planktonic pairs shows a succession of ~1200 year older bottom watera in the Late Glacial to ~250 year in the late Holocene. This indicates circulation and/or ventilation changes through the last deglaciation and Holocene, which we hopefully will be able to date in greater detail with better model estimates of temporal changes in marine reservoir ages.
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| 24. |
- Hellborg, Ragnar, et al.
(author)
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A high resolution AMS-injector for the Pelletron in Lund
- 2002
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In: Pramana. - 0973-7111. ; 59:6, s. 1061-1073
-
Journal article (peer-reviewed)abstract
- A high resolution injector system has recently been installed at the Lund 3 MV tandem Pelletron accelerator. The new injector, designed mainly for Al-26 ions, will increase the experimental potential of the Lund AMS facility considerably. High quality energy- and mass-resolution is obtained by using a 90degrees spherical electrostatic analyzer followed by a 90degrees magnetic analyzer. The injector is equipped with a high intensity sputtering source with a spherical ionizer. A new analytical technique for acceptance calculations as well as PC-based computational methods have been used in the design of the ion optical system of the new injector. Compared to our old injector system which has a magnetic analyzer with a bending angle of only 15degrees, the new system has a more than ten times better resolution. The beam optics of the new system is also better designed to match the accelerator acceptance. In this way the ion transmission from the ion source to the detector, for different ions of interest in our AMS programme, has been increased.
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| 25. |
- Hellborg, Ragnar, et al.
(author)
-
Accelerator Mass Spectrometry
- 2008
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In: Mass Spectrometry Reviews. - : Wiley. - 0277-7037 .- 1098-2787. ; 27:5, s. 398-427
-
Research review (peer-reviewed)abstract
- In this overview the technique of accelerator mass spectrometry (AMS) and its use are described. AMS is a highly sensitive method of counting atoms. It is used to detect very low concentrations of natural isotopic abundances (typically in the range between 10(-12) and 10(-16)) of both radionuclides and stable nuclides. The main advantages of AMS compared to conventional radiometric methods are the use of smaller samples (mg and even sub-mg size) and shorter measuring times (less than 1 hr). The equipment used for AMS is almost exclusively based on the electrostatic tandem accelerator, although some of the newest systems are based on a slightly different principle. Dedicated accelerators as well as older "nuclear physics machines" can be found in the 80 or so AMS laboratories in existence today. The most widely used isotope studied with AMS is (14)C. Besides radiocarbon dating this isotope is used in climate studies, biomedicine applications and many other fields. More than 100,000 (14)C samples are measured per year. Other isotopes studied include (10)Be, (26)Al, (36)Cl, (41)Ca, (59)Ni, (129)I, U, and Pu. Although these measurements are important, the number of samples of these other isotopes measured each year is estimated to be less than 10% of the number of (14)C samples. (c) 2008 Wiley Periodicals, Inc., Mass Spec Rev.
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| 26. |
- Hellborg, Ragnar, et al.
(author)
-
Accelerator mass spectrometry
- 2003
-
In: Romanian Journal of Physics. - 1221-146X. ; 48:1-4, s. 27-37
-
Conference paper (peer-reviewed)abstract
- Accelerator mass spectrometry (AMS) is a world-wide spread technique and nearly 50 AMS laboratories exist today. The most widely spread application of AMS is for radiocarbon dating and an estimated total of nearly 100000 14C samples are measured per year. Other isotopes used are 10Be, 26Al, 36Cl, 41Ca, 129I. The number of these measured per year is estimated to be 10% of the number of 14C samples or even less
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| 27. |
- Hellborg, Ragnar, et al.
(author)
-
Accelerator mass spectrometry - an overview
- 2003
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In: Vacuum. - 0042-207X. ; 70:2-3, s. 365-372
-
Journal article (peer-reviewed)abstract
- The technique of accelerator mass spectrometry (AMS) has spread worldwide since its first demonstration 25 years ago. The equipment used today is very diverse and dedicated accelerators as well as old "nuclear physics machines" can be found in the nearly 50 AMS laboratories today. The most widely spread application of AMS is for radiocarbon dating. However, AMS with C-14 as well as with other long-lived isotopes have also found applications in many other fields in physics and beyond.
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| 28. |
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| 29. |
- Hellborg, Ragnar, et al.
(author)
-
Mechanical design of the recirculating, terminal pumping in the Lund Pelletron, and experimental experience
- 2002
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In: Pramana - Journal of Physics. - 0304-4289 .- 0973-7111. ; 59:5, s. 725-737
-
Conference paper (peer-reviewed)abstract
- A recirculating terminal pumping system has been installed in the 3 MV Pelletron tandem accelerator in Lund. An extremly limited space in the high voltage terminal and the absence of electrical power in the terminal, forced us to provide a unique design for the installation and powering of the new pumps. Details of the technical design, as well as experience of the use of the new system for accelerator mass Spectrometry, will be given.
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| 30. |
- Hellborg, Ragnar, et al.
(author)
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Sources and Detectors in Accelerator Mass Spectrometry
- 2010
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In: The Encyclopedia of Mass Spectrometry: Volume 5 Elemental, Isotopic and Inorganic Analysis by Mass Spectrometry. - 9780080438047 ; 5, s. 613-620
-
Book chapter (other academic/artistic)
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| 31. |
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| 32. |
- Johansson, Cecilia, et al.
(author)
-
Adenoviruses Use Lactoferrin as a Bridge for CAR-Independent Binding to and Infection of Epithelial Cells.
- 2007
-
In: Journal of Virology. - : American Society for Microbiology. - 1098-5514 .- 0022-538X. ; 81:2, s. 954-963
-
Journal article (peer-reviewed)abstract
- Most adenoviruses bind to the coxsackie- and adenovirus receptor (CAR). Surprisingly, CAR is not expressed apically on polarized cells and is thus not easily available to viruses. Consequently, alternative mechanisms for entry of coxsackievirus and adenovirus into cells have been suggested. We have found that tear fluid promotes adenovirus infection, and we have identified human lactoferrin (HLf) as the tear fluid component responsible for this effect. HLf alone was found to promote binding of adenovirus to epithelial cells in a dose-dependent manner and also infection of epithelial cells by adenovirus. HLf was also found to promote gene delivery from an adenovirus-based vector. The mechanism takes place at the binding stage and functions independently of CAR. Thus, we have identified a novel binding mechanism whereby adenovirus hijacks HLf, a component of the innate immune system, and uses it as a bridge for attachment to host cells.
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| 33. |
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| 34. |
- Kiisk, Madis, et al.
(author)
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The charge state distribution of a carbon beam measured at the lund pelletron accelerator with the newly installed terminal pumping system in use
- 2002
-
In: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - 0167-5087. ; 481:1-3, s. 1-8
-
Journal article (peer-reviewed)abstract
- Charge state distributions for (12) C and C-13 ions have been measured at the Lund Pelletron tandem accelerator for the N-2 gas stripper with a newly installed terminal pumping system in use. A comparison of the results obtained for the ion energies between 1.5 and 2.8 MeV with the foil stripper and the gas stripper without terminal pumping demonstrates the great improvement of the stripping process achieved with the new terminal pumping. (C) 2002 Elsevier Science B.V. All rights reserved.
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| 35. |
- Kiisk, Madis, et al.
(author)
-
The charge state distribution of Be, C, Cl and Al ions at the Lund Pelletron accelerator with the recently modified terminal pumping in use
- 2004
-
In: Nuclear Instruments & Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. - : Elsevier BV. - 0167-5087 .- 0168-9002. ; 521:2-3, s. 299-305
-
Journal article (peer-reviewed)abstract
- Some years ago terminal pumping for the gas stripper system at the 3 MV Lund Tandem Pelletron accelerator was installed and charge state distribution measurements using the new installation were reported. Since then, new modifications of the mechanical design of the stripper system have been made. The results of pressure profile measurements as well as the results of charge state distribution measurements in a N-2 and Ar gas stripper at different, new geometrical modifications of the stripper system using C, Be, Al and Cl ion beams are reported. A comparison between pressure profiles obtained for different geometries shows a clear improvement of the vacuum conditions outside the stripper housing for the smallest conductance pipes between the stripper system and the accelerator tubes. These improvements are also well reflected in the charge state distribution measurements, as a higher mean charge state is obtained under the same vacuum conditions in the accelerator tubes for the improved stripper system in comparison with the former mechanical design. (C) 2003 Elsevier B.V. All rights reserved.
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| 36. |
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| 37. |
- Kokfelt, Ulla, et al.
(author)
-
Wetland development, permafrost history and nutrient cycling inferred from late Holocene peat and lake sediment records in subarctic Sweden
- 2010
-
In: Journal of Paleolimnology. - : Springer Science and Business Media LLC. - 0921-2728 .- 1573-0417. ; 44:1, s. 327-342
-
Journal article (peer-reviewed)abstract
- Permafrost in peatlands of subarctic Sweden is presently thawing at accelerated rates, which raises questions about the destiny of stored carbon and nutrients and impacts on adjacent freshwater ecosystems. In this study we use peat and lake sediment records from the Stordalen palsa mire in northern Sweden to address the late Holocene (5,000 cal BP-present) development of the mire as well as related changes in carbon and nutrient cycling. Formation, sediment accumulation and biogeochemistry of two studied lakes are suggested to be largely controlled by the development of the mire and its permafrost dynamics. Peat inception took place at ca. 4,700 cal BP as a result of terrestrialisation. Onset of organic sedimentation in the adjacent lakes occurred at ca. 3,400 and 2,650 cal BP in response to mire expansion and permafrost aggradation, respectively. Mire erosion, possibly due to permafrost decay, led to re-deposition of peat into one of the lakes after ca. 2,100 cal BP, and stimulated primary productivity in the other lake at ca. 1,900-1,800 cal BP. Carbonate precipitation appears to have been suppressed when acidic poor fen and bog (palsa) communities dominated the catchment mire, and permafrost-induced changes in hydrology may further have affected the inflow of alkaline water from the catchment. Elevated contents of biogenic silica and diatom pigments in lake sediments during periods of poor fen and bog expansion further indicate that terrestrial vegetation influenced the amount of nutrients entering the lake. Increased productivity in the lake likely caused bottom-water anoxia in the downstream lake and led to recycling of sediment phosphorous, bringing the lake into a state of self-sustained eutrophication during two centuries preceding the onset of twentieth century permafrost thaw. Our results give insight into nutrient and permafrost dynamics in a subarctic wetland and imply that continued permafrost decay and related vegetation changes towards minerotrophy may increase carbon and nutrient storage of mire deposits and reduce nutrient fluxes in runoff. Rapid permafrost degradation may on the other hand lead to widespread mire erosion and to relatively short periods of significantly increased nutrient loading in adjacent lakes.
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| 38. |
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| 39. |
- Lindstedt Ingemansson, Sandra, et al.
(author)
-
Pulmonary Retransplantation in the Nordic Countries.
- 2015
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In: Annals of Thoracic Surgery. - : Elsevier BV. - 1552-6259 .- 0003-4975. ; 99:5, s. 1781-1787
-
Journal article (peer-reviewed)abstract
- The increasing demand for pulmonary retransplantation (re-LTx) raises ethical issues on the correct allocation of the scarce donor pool. Thus, we performed a thorough review of the current results for re-LTx in the Nordic countries.
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| 40. |
- Magnusson, Åsa, et al.
(author)
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Carbon-14 levels in the vicinity of the Lithuanian nuclear power plant Ignalina
- 2007
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In: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 259:1, s. 530-535
-
Journal article (peer-reviewed)abstract
- Carbon-14 levels in the vicinity of the Lithuanian nuclear power plant Ignalina have been investigated. During 2001-2004, approximately 70 samples were collected and analysed using accelerator mass spectrometry. The study included samples of leaves, grass, moss, soil and aquatic plants, covering a distance up to 32 km from the power plant. The highest C-14 specific activities were found in soil samples from moss-covered sites close to the power plant, probably indicating the release of particulate material. The results are compared with those from studies around other types of reactors also investigated within the project. (c) 2007 Elsevier B.V. All rights reserved.
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| 41. |
- Magnusson, Åsa, et al.
(author)
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Levels of C-14 in the terrestrial environment in the vicinity of two European nuclear power plants
- 2004
-
In: Radiocarbon. - 0033-8222. ; 46:2, s. 863-868
-
Journal article (peer-reviewed)abstract
- Radiocarbon is produced in all types of nuclear reactors. Most of the C-14 released into the environment is in the form of gaseous emissions. Recent data on the C-14 concentration found in terrestrial samples taken in the vicinity of nuclear power plants in Romania and Lithuania are presented. We found increased C-14 levels in the surroundings of both power plants. At the Romanian power plant Cernavoda, we found excess levels of C-14 in grass within a distance of about 1000 in, the highest C-14 specific activity being 311 Bq/kg C (approximately 28% above the contemporary C-14 background) found at a distance of 200 in from the point of release (nearest sampling location). At the Lithuanian power plant Ignalina, samples of willow, pine, and spruce showed a C-14 excess of similar magnitude, while significantly higher values were found in moss samples. The samples were analyzed at the accelerator mass spectrometry facility in Lund, Sweden.
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| 42. |
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| 43. |
- Mei, Ya-Fang, et al.
(author)
-
Comparative analysis of the genome organization of human adenovirus 11, a member of the human adenovirus species B, and the commonly used human adenovirus 5 vector, a member of species C
- 2003
-
In: Journal of General Virology. - : Microbiology Society. - 0022-1317 .- 1465-2099. ; 84:8, s. 2061-2071
-
Journal article (peer-reviewed)abstract
- Adenovirus type 11 (Ad11), a member of the human adenovirus species B (HAdV-B), has a tropism for the urinary tract. The genome of Ad11 was found to comprise 34 794 bp and is 1141 bp shorter than the Ad5 genome of species HAdV-C. The G+C content of the Ad11 genome is 48.9 %, whereas that of Ad5 is 55.2 %. Ad11 and Ad5 share 57 % nucleotide identity and possess the same four early regions, but the E3 region of Ad11 could not be divided into E3A and E3B. The late genes of Ad11 and Ad5 are organized into six and five regions, respectively. Thirty-eight putative ORFs were identified in the Ad11 genome. The ORFs in the late regions, the E2B region and IVa2 show high amino acid identity between Ad11 and Ad5, whereas the ORFs in E1, E2A, E3 and E4, protein IX and the fibre protein show low amino acid identity. The highest and lowest identities were noted in the pre-terminal protein and fibre proteins: 85 % and 24.6 %, respectively. The E3 20.3K and 20.6K ORFs and the L6 agnoprotein were present in the Ad11 genome only, whereas the E3 11.6K cell death protein was identified only in Ad5. All ORFs but the E3 10.3K and L4 pVIII protein vary not only in composition but also in size. Ad11 may have a higher vector capacity than Ad5, since it has a shorter genome and a shorter fibre. Furthermore, in the E3 region, two additional ORFs can be deleted to give extra capacity for foreign DNA.
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| 44. |
- Melazo Dias, C, et al.
(author)
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C-14 content in vegetation in the vicinities of Brazilian nuclear power reactors
- 2008
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In: Journal of Environmental Radioactivity. - : Elsevier BV. - 1879-1700 .- 0265-931X. ; 99:7, s. 1095-1101
-
Journal article (peer-reviewed)abstract
- Abstract in UndeterminedC-14 specific activities were measured in grass samples collected around Brazilian nuclear power reactors. The specific activity values varied between 227 and 299 Bq/kg C. Except for two samples which showed C-14 specific activities 22% above background values, half of the samples showed background specific activities, and the other half had a C-14 excess of 1-18%. The highest specific activities were found close to the nuclear power plants and along the main wind directions (NE and NNE). The activity values were found to decrease with increasing distance from the reactors. The unexpectedly high C-14 excess values found in two samples were related to the local topography, which favors C-14 accumulation and limits the dispersion of the plume. The results indicate a clear C-14 anthropogenic signal within 5 km around the nuclear power plants which is most prominent along northeastwards, the prevailing wind direction.
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| 45. |
- Nyström, Göran, et al.
(author)
-
Takeover-reglerna : en kommentar till lagen om offentliga uppköpserbjudanden på aktiemarknaden och börsernas takeover-regler
- 2013
-
Book (other academic/artistic)abstract
- I detta uppdaterade verk kommenteras NASDAQ OMX Stockholms och Nordic Growth Market NGM:s regler om offentliga uppköpserbjudanden på aktiemarknaden (takeover-reglerna) samt ges en översikt över Kollegiets för svensk bolagsstyrning regler rörande offentliga uppköpserbjudanden på First North, AktieTorget och Nordic MTF. Verket inkluderar också en kommentar till lagen om offentliga uppköpserbjudanden på aktiemarknaden (LUA). Denna tredje upplaga av verket behandlar de reviderade takeover-regler som började gälla den 1 juli 2012 och är ajourförd per den 1 januari 2013 med avseende på bl.a. Aktiemarknadsnämndens avgöranden.
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| 46. |
- Olariu, A, et al.
(author)
-
Dating of some Romanian fossil bones by combined nuclear methods
- 2002
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In: Journal of Radioanalytical and Nuclear Chemistry. - 0236-5731. ; 253:2, s. 307-311
-
Journal article (peer-reviewed)abstract
- A set of fossil bones from Romania has been analysed by accelerator mass spectrometry and by neutron activation analysis in order to estimate their age. The temporal attributing of Malu Rosu archaeological settlement has been extensively analyzed. The radiocarbon age, determined by accelerator mass spectrometry, for this site is 5510+/-200 BP. This is in agreement with the age of 6000+/-2000 BP, obtained by the dating method based on fluorine content, determined by neutron activation analysis.
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| 47. |
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| 48. |
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| 49. |
- Persson, Per, et al.
(author)
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Determination of the detection limit of Ni-59 at the Lund AMS facility by using characteristic projectile X-rays
- 2000
-
In: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - 0168-583X. ; 160:4, s. 510-514
-
Journal article (peer-reviewed)abstract
- Accelerator mass spectrometry (AMS) is an ultra-sensitive method for counting atoms, both radionuclides and stable nuclides. When using small tandem accelerators to measure heavy isotopes, interfering isobars are often troublesome. One way to reduce this interference is to combine AMS with the detection of characteristic X-rays of the projectile. After analysis in the AMS system it is possible to identify ions of different atomic number by their characteristic X-rays, by slowing down the ions in a suitable target. In this paper, the detection limit of Ni-59 at the Land AMS facility is reported. A method for the chemical extraction of nickel from stainless steel, combined with a purification step to reduce the cobalt content in the sample by several orders of magnitude, is also described. (C) 2000 Elsevier Science B.V. All rights reserved.
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| 50. |
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