| 1. |
- Anderson, Leif G., et al.
(författare)
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The effect of the Siberian tundra on the environment of the shelf seas and the Arctic Ocean
- 1999
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Ingår i: Ambio. - 0044-7447. ; 28:3, s. 270-280
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Tidskriftsartikel (refereegranskat)abstract
- The Tundra Ecology -94 expedition investigated inflow of inorganic and organic carbon to the shelf seas by river runoff, and its transformation by biochemical processes in seawater and sediment. In addition, anthropogenic radionuclides, 137Cs, 90Sr, and 239,240Pu, were studied in water and sediments. The distribution of dissolved inorganic carbon indicates that the majority of the Ob and Yenisey discharges flow into the Laptev Sea before entering the central Arctic Ocean. The sediment study shows that there is a marked difference in benthic oxygen uptake, efflux of dissolved inorganic carbon and nutrients between localities. 137Cs activity from the Chernobyl accident is 30% in the Barents, Kara, and Laptev Seas. 137Cs increased from 5-8 Bq m-3 in Barents Sea, 5-13 Bq m-3 in the Kara Sea to 8-15 Bq m-3 in the Laptev Sea, but with locally low concentrations at the river mouths. Corresponding values for 90Sr were 2.5, 3, and 4 Bq m-3, respectively.
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| 2. |
- Doedens, Espen, 1988, et al.
(författare)
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Surface preparations on MV-sized cable ends for ramped DC breakdown studies
- 2016
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Ingår i: Annual Report - Conference on Electrical Insulation and Dielectric Phenomena, CEIDP. - 0084-9162. ; , s. 360-362
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Konferensbidrag (refereegranskat)abstract
- The rising demand for HVDC crosslinked polyethylene (XLPE) cable systems has put many novel products and solutions on the market within the recent years. In order to assess electrical performance of physical interfaces, DC breakdown studies of XLPE cable samples have been performed. For these samples, the surface of the XLPE in the cable ends has been modified using different techniques. Besides changing the surface preparation method, also the impact of the test conditions has been studied. A slowly ramped DC voltage has been used in order to study the breakdown characteristics for the samples. A great impact on breakdown voltage was found depending on which surface preparation was used. This highlights the fact that interfaces indeed play an important role for HVDC applications.
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| 3. |
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| 4. |
- Lood, Yvonne, et al.
(författare)
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Determination of testosterone in serum and saliva by liquid chromatography-tandem mass spectrometry : An accurate and sensitive method applied on clinical and forensic samples
- 2021
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Ingår i: Journal of Pharmaceutical and Biomedical Analysis. - : Elsevier. - 0731-7085 .- 1873-264X. ; 195
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Tidskriftsartikel (refereegranskat)abstract
- A highly sensitive and accurate electrospray liquid chromatography tandem-mass spectrometry (ESI-LC-MS/MS) method for determination of testosterone in human serum and saliva was developed and validated. Accurate quantification of testosterone in human matrices is essential in diagnosis and management of androgen status in men, women and children, and in forensic investigations of suspected abuse of anabolic androgenic steroids. Chromatography was performed on an HSS-T3 C18 column with a total run-time of 5.5 min. The tandem mass spectrometry was operated in positive electrospray ionization mode with multiple reaction monitoring. Serum and saliva samples of 200 μL, were prepared by solid-phase extraction using a 96-well plate following precipitation with 200 μL methanol. 13C labeled testosterone was used as internal standard for quantification. The standard curve was linear within the range of 4-1000 pg/mL and the limit of quantification of both serum and salivary testosterone was 4 pg/mL. Accuracy were 99-101 % and 93-95 % with between-run imprecision in serum and saliva, respectively, and inter- and intra-assay coefficients of variation were less than 9.2 %. The method proved to be applicable for determination of testosterone over a wide range of concentrations in serum and saliva samples from clinical patients with various androgen disorders, healthy male and female adults as well as from forensic cases.
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| 5. |
- Lood, Yvonne
(författare)
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Testosterone Use and Abuse : Methodological Aspects in Forensic Toxicology and Clinical Diagnostics
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Abuse of anabolic androgenic steroids (AAS) is widespread in society and is today a major public health problem, associated with mental and somatic adverse effects and risk behavior, such as use of other illicit drugs and criminality. Testosterone, the most important endogenous male androgen, is therapeutically used in replacement therapy but is also extensively used as a doping agent. Traditionally, testosterone abuse is detected in urine in forensic cases and in serum in clinical diagnosis and monitoring, and free bioavailable serum testosterone is calculated by formulas. Salivary testosterone is however an attractive biomarker, as testosterone in saliva is supposed to reflect free testosterone in serum. The aim of this thesis was to investigate the abuse of AAS from a forensic perspective, particularly focusing on testosterone and methodological problems and potential alternative matrices for measurements of testosterone in forensic and clinical assessments. In the first study the toxicological findings in individuals suspected of doping offences, registered in the Swedish national forensic toxicology database were investigated (paper I). In paper II, testosterone levels in serum, saliva, and urine in clinical patients during replacement therapy with testosterone undecanoate (Nebido®) were studied. Further, the sensitivity of the current procedure for detection of testosterone abuse was investigated by method comparison using isotope ratio measurement (paper III) and a quantitative LC-MS/MS method for testosterone in serum and saliva was developed and presented (paper IV). It was found that testosterone was most frequently detected in the forensic cases and co-abuse of narcotics was common among AAS abusers. Methodological problems in detection of testosterone abuse using the present procedures was identified, indicating a need for new analytical strategies. A sensitive and highly specific LC-MS/MS method was developed for determination of testosterone in serum and saliva, which was shown suitable for analysis of forensic and clinical samples. Salivary testosterone was shown to correlate well with free serum testosterone in both male and female, and a sensitive marker in testosterone therapy, especially in females. In conclusion, it was found that saliva might have a potential as an alternative matrix for detection of illicit administration of testosterone and for diagnosis and monitoring of androgenic status.
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| 6. |
- Persson, Bertil R, et al.
(författare)
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Radioactivity Exploration from the Arctic to Antarctica. Part 5: The Tundra-94 expedition
- 2015
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Ingår i: Acta Scientiarum Lundensia. - 1651-5013. ; 2015:006, s. 1-20
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Tidskriftsartikel (refereegranskat)abstract
- The joint Swedish-Russian “Tundra Ecology-94” expedition during 1994 used the large Russian ice-breaking research vessel R/V Akademik Fedorov a platform and went along a coastline of 3500 km-from the Kola Peninsula 10°E to Kolyuchinskaya Bay 173°E. Radioactivity in air, seawater and sediment was explored at various locations along the route. The average of 7Be activity concentration in air over the Arctic Ocean was found to be only about 0.6 mBq.m-3, in air close to the Siberian coast-line, however, it was as high as 11 mBq.m-3. The activity concentration of 210Pb in the air over the Arctic Ocean varies between 37 – 176 micro-Bq.m-3. In the air close to the Siberian coastline 71oN 84oE, however, the activity concentration of 210Pb in the air was much higher, about 2500 micro.Bq.m-3. Anthropogenic radioactivity in the Arctic originate from nuclear weapons fallout, release from nuclear fuel reprocessing plant, and from the Chernobyl accident. The minimum values of the 137Cs activity concentration water along the route of the Tundra were found in South-eastern Barents Sea: 5.3 Bq.m-3 of surface-water, and of bottom-water 6.4 Bq.m-3. Maximum values were found in the Western Laptevsea: 12.8 Bq.m-3 of surface-water, and of bottom-water 5.1 Bq.m-3. East of 150 oE the 134Cs / 137Cs ratios are less than 0.003, indicating that less than 6% of the 137Cs originated from the Chernobyl accident. 137Cs levels are reduced to values of about 1.4 Bq.m-3 in the low salinity water near the mouths of the Ob and Yenisey Rivers. The 134Cs / 137Cs activity ratio of 0.014 in the freshwater indicates that the Chernobyl component in the river systems is the same (30%) as in the marine waters west of 150 oE. In surface water the 90Sr activity concentration range from 2 to 4 Bq.m-3, Maximuim values about 3.5 Bq.m-3 were found between 100-140 oE. But east of 150 oE the values decreased to about 0.5 Bq.m-3 at 170 oE. In bottom water the 90Sr activity concentration range from 1.5 at 40 oE to maximum values about 4 Bq.m-3 between 100-120 oE. . The measured 90Sr/137Cs ratios in surface water close to a value of 0.14 over a wide range of stations from the Barents to the Laptev Seas. The 129I concentration in sea-water along the route of the Tundra expedition decrease from about 20·1011 atoms.l-1 at 40 oE, to about 1·1011 atoms.l-1 east of 160 oE. The 239+240Pu activity concentration in surface seawater decrease from about 10 mBq.m-3 to about 1 mBq.m-3 east of 160 oE. In bottom seawater it is more evenly distributed between 10-4 mBq.m-3, with minimum at 60-80 oE and maxima at 40oE and 160 oE. Measured 238Pu/239,240Pu activity ratios in the water column yield no evidence of any leakage of plutonium from dumped nuclear wastes in the Kara and Barents Seas.
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| 7. |
- Persson, Bertil R, et al.
(författare)
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Radioactivity exploration from the Arctic to the Antarctic. Part 4: The Arctic Ocean-91 expedition
- 2015
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Ingår i: Acta Scientiarum Lundensia. - 1651-5013. ; 2015:005, s. 1-14
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Tidskriftsartikel (refereegranskat)abstract
- The Arctic Ocean expedition in 1991 with the Swedish icebreaker M/S Oden was focused on oceanography and geology. The aim of our project was exploring the activity concentrations in surface air of 7Be, 210Pb. and 210Po in the surface air, radioactive isotopes of Caesium (134Cs, 137Cs) and plutonium (239+240Pu) in seawater. During the cruise in the Arctic Ocean during 1991-07-28 to 1991-10-04 the average activity concentrations in surface air of 7Be was 0.6±0.4 mBq.m-3 , 210Pb 46±34 microBq.m-3 and 210Po 37±23 microBq.m-3 The activity concentration of 137Cs in the surface of the Arctic Ocean was in the range of 8-12 Bq.m-3. When crossing the Nansen basin the activity concentration of 137Cs increased to about 18 Bq.m-3 at 88 °N 80 °E, and there was an accumulation of 137Cs in an area around at 88 °N and 80-100 °E and locally increased activity at 83 °N 10 °E. The 134Cs/137Cs activity ratios was about 0.02 due to the contribution mainly from Sellafield and a few percent contribution from Chernobyl. The 134Cs/137Cs activity ratio decreased to about 0.002-0.005 in areas of high 137Cs activity concentration which exclude contribution of 134Cs of nuclear reactor fuel. The activity concentration of 239+240Pu in the surface of the Arctic Ocean was in the range of 6 - 8 mBq.m-3. But locally the activity concentration of 239+240Pu was found to be increased to 11 mBq.m-3 at 86°N 48-53°E, and to 16 mBq.m-3 at 83°N 10°E.
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| 8. |
- Persson, Bertil R, et al.
(författare)
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Radioactivity Exploration from the Arctic to the Antarctic. Part 6: The Arctic Ocean-96 expedition
- 2015
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Ingår i: Acta Scientiarum Lundensia. - 1651-5013. ; 2015:007, s. 1-22
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Tidskriftsartikel (refereegranskat)abstract
- The Swedish Arctic Ocean-96 expedition arranged by the Swedish Polar Research Committee took place during 1996 with the Swedish icebreaker M/S Oden. The expedition focused on studying the distribution of radionuclides in different water masses in the central Arctic Ocean. The expedition crossed the Barents Sea, entered the Nansen Basin at the St. Anna Trough, and continued north across the Amundsen Basin. The main part of the expedition was concentrated on the north Lomonosov Ridge and the return route passed the North Pole and went south along 10 oE towards Svalbard. In both legs, water samples in the surface and subsurface layers were collected for the determination of fission products and transuranic elements in seawater and sediment. The highest 137Cs, 90Sr and 129l activities and 134Cs/137Cs activity ratios are found in a band stretching from the northern Lomonosov Ridge, over the North Pole and south along 10-15 oE to 85 oN. The releases from European nuclear fuel reprocessing plants and Chernobyl fallout traced by the 129I and 134Cs/137Cs signals respectively have approximately the same spatial distribution in the Arctic Ocean surface layer. The activity concentration of 90Sr in surface water is about 2 Bq.m-3. For 239+240Pu the lowest concentrations in the surface water of 4 mBq.m-3 was found on the Lomonosov Ridge and in the Makarov Basin. In the Eurasian Basin, the concentrations 239+240Pu are about 13 mBq.m-3 . For all the radionuclides analysed, the water profiles generally show activities decreasing with depth. An exception is the high 137Cs activity concentrations found in the lower halocline layer at the Lomonosov Ridge and Makarov Basin stations. The maxima were not observed in the 90Sr or l29l measurements. It is assumed to be due to a contribution of Chernobyl fallout to the Arctic Ocean surface layers in the years around 1990. Inventories down to 900 m death reveal that between 60-70 % of the 137Cs, 90Sr and in the Arctic Ocean water, are present in the surface layer inflow from the Atlantic. The total inventories down to 900 m in the Eurasian Basin of the Arctic Ocean estimate to 6.7 PBq for 137Cs, 3.4 PBq for 90Sr and 5.3x1028 atoms for 129l.
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| 9. |
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| 10. |
- Tejland, Pia, 1978, et al.
(författare)
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Oxidation Mechanism in Zircaloy- 2—The Effect of SPP Size Distribution
- 2015
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Ingår i: ASTM Special Technical Publication. - 0066-0558. - 9780803175297 ; 1543, s. 373-403
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Konferensbidrag (refereegranskat)abstract
- The metal/oxide interface region in Zircaloy-2 oxidized in autoclave was studied with transmission electron microscopy (TEM) and atom probe tomography. In addition to waviness on the micrometer scale the metal/oxide interface was found to have irregularities on a finer scale, and metal islands were found especially at metal hills (delayed parts of the oxidation front). The thickness of the sub-oxide layer varies considerably along the interface in the same sample, from 100 to virtually 0 nm. The sub-oxide composition may vary on a very fine scale (down to 5nm), and it can sometimes be a mixture of sub-oxides with different oxygen content. The metal matrix in contact with the sub-oxide is saturated with up to 32 at. % oxygen, and the oxygen diffusion profile in the metal is in approximate agreement with literature data for pure Zr. However, the diffusion length appears to be somewhat larger at interface metal hills than under valleys, probably for both geometrical and stress state reasons. Hydride precipitates, hardly visible in conventional TEM, give a good image contrast when employing high angle annular dark field imaging. A model for the oxidation process is presented, where the creep deformation of the metal close to the interface and the formation of lateral cracks in the oxide are of highest importance. The effect of second phase particle (SPP) size is suggested to be twofold: Small and numerous SPPs give a stronger metal and therefore higher stress in the oxide. Small SPPs also nucleate many more lateral cracks in the oxide, which gives a weaker oxide. Together this leads to formation of large cracks associated with transition in the oxidation rate at an earlier time than for a material with larger and fewer SPPs, and thereby a higher oxidation rate.
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