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- Frodelius, Jenny, 1978-, et al.
(författare)
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Annealing of thermally sprayed Ti2AlC coatings
- 2011
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Ingår i: INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY. - : Blackwell. - 1546-542X. ; 8:1, s. 74-84
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Tidskriftsartikel (refereegranskat)abstract
- Phase transformations during annealing of coatings sprayed with the High Velocity Oxy-Fuel technique using Ti2AlC powder have been investigated by in-situ x-ray diffraction. The asdeposited coatings, consisting of Ti2AlC, Ti3AlC2, TiC, Ti-Al, and oxides, are stable up to 500 °C. Ti3AlC2 forms above 550 °C and Ti2AlC forms above 700 °C by intercalation of Al into TiCx. For temperatures between 900 and 1100 °C, Ti3AlC2 and Ti2AlC decompose by losing Al to the surrounding matrix resulting in TiCx, and Al2O3. The thermal expansion coefficient between ambient and 700°C is 11.9·10-6 K-1. The thermal diffusivity at room temperature is 1.9·10-6 m2/s.
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- Eklund, Jenny M., et al.
(författare)
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Keeping delinquency at bay : the role of the school context for impulsive and sensation-seeking adolescents
- 2014
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Ingår i: European Journal of Criminology. - : SAGE Publications. - 1477-3708 .- 1741-2609. ; 11:6, s. 682-701
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Tidskriftsartikel (refereegranskat)abstract
- Previous research shows that a disadvantaged school setting is associated with increased risk of adolescent delinquency. However, there is limited research on individual differences in such contextual effects. In this study, we investigated whether the association between impulsive and sensation-seeking traits and delinquency is modified by the school setting, focusing on schools’ socioeconomic and ethnic composition and average school performance. We also examined whether the association between gender and delinquency varies by school context. Participants were adolescents in ninth grade from the Stockholm School Survey (5619 pupils in 89 schools). The findings showed an attenuating effect of school advantage on adolescents’ individual risk of delinquency. Impulsive and sensation-seeking adolescents, and boys in particular, committed less crime if they attended more advantaged schools.
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3. |
- Eklund, Jenny M., et al.
(författare)
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Romantic relationships and delinquent behaviour in adolescence : the moderating role of delinquency propensity
- 2010
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Ingår i: Journal of Adolescence. - : Wiley. - 0140-1971 .- 1095-9254. ; 33:3, s. 377-386
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Tidskriftsartikel (refereegranskat)abstract
- There is some evidence that adolescent romantic involvement is associated with delinquent behaviour. One aim of this longitudinal study was to determine whether this holds for romantic relationships deemed important by the participants. A second aim was to test whether this association was stronger for adolescents with pre-existing delinquent behaviour and personality traits of impulsivity and thrill seeking (delinquency propensity). Sex differences also were examined. Participants were 686 7th and 8th grade students who completed three assessments over three years. The results showed that delinquency was associated with earlier romantic relationships among those who were higher in delinquency propensity one year earlier. This association was stronger among girls than boys. Thus, romantic relationships amplified girls' and boys' existing delinquency propensity, but this was strongest among girls. (C) 2009 The Association for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.
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- Håkanson, Lars, et al.
(författare)
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Relationships Between Chlorophyll, Salinity, Phosphorus, and Nitrogen in Lakes and Marine Areas
- 2010
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Ingår i: Journal of Coastal Research. - : Coastal Education and Research Foundation. - 0749-0208 .- 1551-5036. ; 26:3, s. 412-423
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Tidskriftsartikel (refereegranskat)abstract
- This work presents empirical data from several databases Empirical data ultimately form the basis for most ecological/environmental studies, and this work uses what may be the most comprehensive data set ever compiled concerning relationships between chlorophyll-a concentrations, nitrogen, phosphorus, and salinity, since the data in this study concerns about 500 lakes and coastal areas The focus has been on how variations between systems in median summer values of chlorophyll-a concentrations (Chl) depend on variations in total nitrogen, total phosphorus, and salinity The salinities range from 0 to 275 PSS78 in hypersaline systems, the median salinity is 12 5 The range in nutrients is from ultraoligotrophic (totalP, or TP, is less than 1 mu g/L) to hypertrophic systems (TP is greater than 1000 mu g/L) The chlorophyll values vary from 0 12 to 60 mu g/L Results showed that there is a minimum in the Chl/TP ratio in the salinity range between 2 and 5, followed by an increase up to a salinity range of 10-15, and then a continuous reduction in the Chl/TP ratio until a minimum value of about 0 012 is reached in hypersaline systems We have also identified a threshold value for the salinity In systems dominated by freshwater influences, the ratio of Chl to total nitrogen, or TN, increases steadily from about 0 008 in lakes to 0 02 when the salinity is 10 At higher salinities than 10, the Chl/TN ratio decreases in a nonlinear fashion We have also presented several empirical models to predict chlorophyll concentrations from levels of TP, TN, and salinity The model predicting Chl from TP and salinity is generally the best one The next best model according to the criteria (r(2) value, median error, and standard deviation for the error) is the model using TN and salinity Models not including salinity predict chlorophyll less well
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