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- Åström, H., et al.
(författare)
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Hot cracking and micro-segregation in 18-1 0 stainless steel welds
- 1976
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Ingår i: Metal Science. - : Maney Publishing. - 0306-3453. ; 10:7, s. 225-234
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Tidskriftsartikel (refereegranskat)abstract
- Advanced quantitative chemical and image analysis techniques based on scanning and scanning-transmission electron miCroscopy have been used to study hot cracking and micro-segregation in an 18%Cr-10%Ni weld metal. It is found that the main cause of hot cracking is sulphur segregation. In fully austenitic welds, manganese remains in solution and when the last of the S-rich 'melt solidifies Mn is simply not available to break up the sulphide films. The present practice of substantially increasing the amount of Mn in austenitic welds, or adding cerium, would thus seem to be justified. Phosphorus also aggravates the problem of hot cracking, but fortunately it does not appear to segregate so markedly as sulphur, being much more soluble in austenite. If the weld metal is so alloyed that solidification to the two-phase austenite plus ferrite occurs, hot cracking does not occur. The two main reasons are concluded to be: (1) manganese is less soluble in ferrite than austenite and a sufficient quantity of Mn is evidently released to combine with S and form inclusions; (2) the structural refinement of two-phase structures, compared to the single-phase austenite, results in a more even distribution of Sand P throughout the weld metal, and marked segregation is thus avoided.
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| 6. |
- Loberg, E. M., et al.
(författare)
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Psychosocial characteristics differentiate non-distressing and distressing voices in 10,346 adolescents
- 2019
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Ingår i: European Child & Adolescent Psychiatry. - : Springer Science and Business Media LLC. - 1018-8827 .- 1435-165X. ; 28:10, s. 1353-1363
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Tidskriftsartikel (refereegranskat)abstract
- Adolescents hearing non-existent voices may be at risk for psychosis, but the prevalence of voice-hearing (VH) in the general population complicates clinical interpretations. Differentiating between VH with and without distress may aid treatment decisions in psychosis services, but understanding the differences between these two phenomena as they present in the normal adolescent population is necessary to validate this differentiation. The present study compared VH with and without distress in 10,346 adolescents in relation to clinical characteristics, known risk factors, predictors and psychosocial moderators of psychosis. A population-based cohort of Norwegian 16-19 years old adolescents completed a comprehensive web-based questionnaire, including two questions from the extended Launay-Slade Hallucinations Scale: (1) I often hear a voice speaking my thoughts aloud and (2) I have been troubled by hearing voices in my head. Adolescents reporting no VH, non-distressing VH or distressing VH were compared on 14 psychosocial and clinical variables. A multinomial regression model showed that non-disturbing voices were predicted by better school grades, social dysfunction, distractibility, affective symptoms and experience of trauma, while the disturbing voices were predicted by the experience of bullying and trauma, perceived negative self-worth and self-efficacy, less family support, dysregulation of activation, distractibility, self-harm and anxiety. Hearing voices without distress versus being distressed by the voices is related to different constellations of psychosocial variables, suggesting that they represent two separate groups of adolescents. The findings validate the emphasis on distress in clinical practice.
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