| 1. |
- Johnsson, Filip, 1960, et al.
(författare)
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In-furnace processes in a 235 MWe CFB boiler
- 2002
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Ingår i: Proc. of the 7th International Conference on Circulating Fluidized Beds. - 9780920804988 ; , s. 607-614
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Konferensbidrag (refereegranskat)abstract
- In an experimental project funded by the 5th Framework Programme of the European Community (EC), different measurement techniques are used to analyze in-furnace processes in a 235 MWe Circulating Fluidized Bed (CFB) boiler in Turow, Poland. The purpose of the project is to assess the insufficiently known features of large-scale CFB boilers. The furnace of the boiler has a cross-section of 21 x 10 meters and a height of 43 meters. The boiler is operated on a local brown coal. Steady state, as well as dynamic conditions, are studied. The project is unique in two respects: Firstly, several measurement ports are provided in the large CFB furnace for in-situ measurements in various locations on the furnace. Secondly, a number of measurement techniques are employed. These facilitate studies of hydrodynamic processes as well as local variations in gas components (such as O2, CO, THC) and solids materials. The paper describes the measurement techniques and provides examples of the first (hydrodynamic) results obtained by the in-situ measurements.
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| 2. |
- Kallner Bastviken, Sofia, et al.
(författare)
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Effects of vegetation and hydraulic load on seasonal nitrate removal in treatment wetlands
- 2009
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Ingår i: Ecological Engineering. - Amsterdam : Elsevier. - 0925-8574 .- 1872-6992. ; 35:5, s. 946-952
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Tidskriftsartikel (refereegranskat)abstract
- Optimising nitrate removal and identifying critical factors for nitrate removal in wetlands is an important environmental task in the effort to achieve better surface water quality. In this study, eighteen free water surface wetlands with similar shape and size (22 m2 each) received groundwater with a high nitrate-N concentration (about 11 mg l−1). The effects of two hydraulic loads, 0.13 m d−1 and 0.39 m d−1, and three vegetation types – emergent, submersed and freely developing vegetation – on the nitrate-N removal were investigated through mass inflow and outflow measurements.No significant difference in nitrate removal between the different hydraulic loads could be detected. Significantly higher area-specific nitrate removal and first-order area-based rate coefficients were found in the basins with emergent vegetation, with no difference between the basins with submersed and freely developing vegetation. The nitrate-N removal increased as the wetlands matured and the vegetation grew denser, emphasizing the role of dense emergent vegetation for nitrate removal at high nitrate concentrations.
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| 3. |
- Lundin, Cecilia, et al.
(författare)
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Hormonal Contraceptive Use and Risk of Depression Among Young Women With Attention-Deficit/Hyperactivity Disorder
- 2023
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Ingår i: Journal of the American Academy of Child and Adolescent Psychiatry. - : Elsevier BV. - 0890-8567 .- 1527-5418. ; 62:6, s. 665-674
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Women with attention-deficit/hyperactivity disorder (ADHD) have an increased risk of becoming teenage mothers. Adverse effects of hormonal contraception (HC), including depression, may affect adherence to user-dependent contraception and increase the risk for unplanned pregnancies and teenage births in women with ADHD. The current study analyzed whether girls and young women with ADHD are at increased risk for depression during HC use compared with women without ADHD.Method: A linkage of Swedish national registers covering 29,767 girls and young women with ADHD aged 15 to 24 years and 763,146 without ADHD provided measures of ADHD and depression diagnoses (International Classification of Diseases [ICD] code) and prescription of stimulant medication, HC, and antidepressant medication (Anatomical Therapeutic Chemical [ATC] code). Cox regression models applying an interaction term (ADHD diagnosis x HC use) evaluated the excess risk of HC-induced depression in women with ADHD.Results: Women with ADHD had a 3-fold higher risk of developing depression, irrespective of HC use (adjusted hazard ratio [aHR] = 3.69, 95% CI = 3.60-3.78). Oral combined HC users with ADHD had a 5 times higher risk of depression compared with women without ADHD who were not using oral combined HC (aHR = 5.19, 95% CI = 4.94-5.47), anda 6 times higher risk in comparison with women without ADHD who were on oral combined HC (aHR = 6.10 (95% CI = 5.79-6.43). The corresponding risk of depression in women with ADHD who used a progestogen-only pill (aHR = 5.00, 95% CI = 4.56-5.49). The risk of developing depression when using non-oral HC was similarly moderately increased in both groups.Conclusion: Girls and young women with ADHD have an increased risk of developing depression when using oral HC compared with their un-affected peers. Information on risks with HCs as well as potential benefits with long-acting reversible contraceptives needs to be an integrated part of the shared decision making and contraception counseling for young women with ADHD.
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| 4. |
- Niemeyer Hultstrand, Jenny, et al.
(författare)
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Hormonal contraception and risk of breast cancer and breast cancer in situ among Swedish women 15-34 years of age : A nationwide register-based study
- 2022
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Ingår i: The Lancet Regional Health. - : Elsevier. - 2666-7762. ; 21
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Tidskriftsartikel (refereegranskat)abstract
- Background: Evidence on a possible association between newer hormonal contraceptives (HC) and risk of breast cancer remains inconclusive, especially as concerns progestogen-only methods.Methods: In this nationwide prospective cohort study, all Swedish women aged 15-34 at study start on January 1st 2005, or who turned 15 years during the study period, were followed until December 31st 2017. Using information from seven National Registers, we assessed the risk ratio of developing breast cancer and breast cancer in situ in relation to different HC using Poisson regression. We adjusted the analyses for several known confounders of breast cancer.Findings: This cohort included 1.5 million women providing more than 14 million person-years. During the study period, 3842 women were diagnosed with breast cancer. Compared with never users of any HC, we found no increased risk of developing breast cancer among current users of any combined HC, IRR 1.03 (0.91-1.16), whereas current users of progestogen-only methods had an increased risk of developing breast cancer, IRR 1.32 (1.20-1.45). Across all types of HC, the risk of developing breast cancer appeared to be highest the first five years of use (combined HC IRR 1.39 (1.14-1.69); progestogen-only methods IRR 1.74 (1.44-2.10). The risk disappeared ten years after the women stopped using HC. The absolute risk of breast cancer per 100,000 women-years was 22.4 for never users, 10.9 for current users of combined HC, and 29.8 for current users of progestogen-only methods.Interpretation: Current use of progestogen-only methods is associated with a small increased risk of developing breast cancer, whereas we could only detect an increased risk among users of combined HC during the first five years of use. This may partly be explained by a selective prescription of progestogen-only methods to women with risk factors for breast cancer, like smoking or obesity. As the absolute risk of breast cancer was small, the many health benefits associated with HC must also be taken into account in contraceptive counselling.
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| 5. |
- Stenhammar, Elin, et al.
(författare)
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Levonorgestrel intrauterine device and depression : A Swedish register-based cohort study
- 2023
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Ingår i: International Journal of Psychophysiology. - : Elsevier. - 0167-8760 .- 1872-7697. ; 193
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Tidskriftsartikel (refereegranskat)abstract
- Background: The levonorgestrel intrauterine device (LNG-IUD) is traditionally viewed as a safe contraceptive with limited systemic effects. However, three recent studies have indicated an increased risk of depression subsequent to LNG-IUD use. This study aimed to examine the potential associated risk between LNG-IUDs and depression, and determine which women are at risk.Methods: This longitudinal cohort study was based on data from seven Swedish national population-based registers. All Nordic-born women aged 15-24 years residing in Sweden between 2010 and 2017 were included. Cox regression was implemented to estimate the adjusted hazard ratio (AHR) for developing depression, defined as first depression diagnosis or redeemed prescription for antidepressant treatment. We adjusted for age, education level, parental country of origin, parental psychiatric health, previous hormonal contraceptive use and medical indications for contraceptive use.Findings: 703,157 women were included in the analysis. The LNG-IUD was associated with 57 % increased risk of depression [AHR 1.57 (95 % CI 1.51-1.64)]. The greatest risk increase was seen in adolescent women [AHR 2.57, (95 % CI 2.36-2.80)] and women who used the LNG-IUD as their first hormonal contraceptive method [AHR 1.63, (95 % CI 1.50-1.78)]. The risk of depression decreased at the end of study period [AHR 1.43, (95 % CI 1.36-1.51)], once the LNG-IUD became more widely accessible among nulliparous women.Conclusions: Adolescent women who use the LNG-IUD as their first-ever hormonal contraceptive are at increased risk of developing depression. However, additional impact from confounding factors is likely as risk estimates decreased over the study period. Further research needs to determine if there is a causal relationship between LNG-IUDs and depression.
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| 6. |
- Weisner, Stefan E.B, et al.
(författare)
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Influence of alternative states on nitrogen removal in experimental wetlands
- 2007
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Ingår i: 2nd International Symposium on Wetland Pollutant Dynamics and Control - WETPOL 2007. - Tartu : Institute of Geography, University of Tartu. - 9789949116881 ; , s. 357-359
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Denitrification is the main process that remove nitrate from the water in wetlands. Plants can supply denitrifying bacteria with organic carbon and suitable attachment surfaces (Weisner et al. 1994). They also promote the development of anaerobic conditions through litter accumulation and decomposition, which would favour denitrification. The presence of plants has been shown to enhance nitrate removal in field studies (Bachand and Horne 2000). Toet et al. (2005) found a higher nitrogen removal in wetland compartments with emergent plants than with submersed plants. Results from microcosm studies have shown that the potential for denitrification is specific for different plant species (Bastviken et al. 2005).Wetlands may typically exist in alternative states, dominated by different kinds of vegetation. The purpose of this study was to investigate the effect of alternative state on nitrogen removal under controlled conditions in experimental wetlands.
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