| 1. |
- Beckman, Linda, 1980-, et al.
(författare)
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Effects on alcohol use of a Swedish school-based prevention program for early adolescents: a longitudinal study
- 2017
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Ingår i: BMC Public Health. - London, United Kingdom : Springer Science and Business Media LLC. - 1471-2458. ; 17
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Tidskriftsartikel (refereegranskat)abstract
- Background: The aim of the study was to address the lack of evaluations of school-based substance use prevention programs and to conduct a quasi-experimental evaluation of the alcohol use part of the Triad intervention. Methods: Eleven Swedish intervention schools (285 pupils) and three control schools (159 pupils) participated in the evaluation. Baseline measurements were conducted in 2011 before the alcohol part in the prevention program was implemented in the intervention schools (school year 6, ages 12-13). We estimated an Intention-To-Treat (ITT) Difference-in-Difference (DD) model to analyze the effectiveness of the intervention on subsequent alcohol use measured in grades 7, 8 and 9. Results: The main results show no effect on the likelihood of drinking alcohol or drinking to intoxication. Conclusions: The lack of positive effects highlights the need for policy-makers and public health officials need to carefully consider and evaluate prevention programs in order to ensure that they are worthwhile from school, health, and societal perspectives.
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| 2. |
- Eriksson, Mimmi, et al.
(författare)
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Effects of Gas Layer Thickness on Capillary Interactions at Superhydrophobic Surfaces
- 2024
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 40:9, s. 4801-4810
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Tidskriftsartikel (refereegranskat)abstract
- Strongly attractive forces act between superhydrophobic surfaces across water due to the formation of a bridging gas capillary. Upon separation, the attraction can range up to tens of micrometers as the gas capillary grows, while gas molecules accumulate in the capillary. We argue that most of these molecules come from the pre-existing gaseous layer found at and within the superhydrophobic coating. In this study, we investigate how the capillary size and the resulting capillary forces are affected by the thickness of the gaseous layer. To this end, we prepared superhydrophobic coatings with different thicknesses by utilizing different numbers of coating cycles of a liquid flame spraying technique. Laser scanning confocal microscopy confirmed an increase in gas layer thickness with an increasing number of coating cycles. Force measurements between such coatings and a hydrophobic colloidal probe revealed attractive forces caused by bridging gas capillaries, and both the capillary size and the range of attraction increased with increasing thickness of the pre-existing gas layer. Hence, our data suggest that the amount of available gas at and in the superhydrophobic coating determines the force range and capillary growth.
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| 3. |
- Eriksson, Mimmi, et al.
(författare)
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Effects of liquid surface tension on gas capillaries and capillary forces at superamphiphobic surfaces
- 2023
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Ingår i: Scientific Reports. - : Springer Nature. - 2045-2322. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- The formation of a bridging gas capillary between superhydrophobic surfaces in water gives rise to strongly attractive interactions ranging up to several micrometers on separation. However, most liquids used in materials research are oil-based or contain surfactants. Superamphiphobic surfaces repel both water and low-surface-tension liquids. To control the interactions between a superamphiphobic surface and a particle, it needs to be resolved whether and how gas capillaries form in non-polar and low-surface-tension liquids. Such insight will aid advanced functional materials development. Here, we combine laser scanning confocal imaging and colloidal probe atomic force microscopy to elucidate the interaction between a superamphiphobic surface and a hydrophobic microparticle in three liquids with different surface tensions: water (73 mN m−1), ethylene glycol (48 mN m−1) and hexadecane (27 mN m−1). We show that bridging gas capillaries are formed in all three liquids. Force-distance curves between the superamphiphobic surface and the particle reveal strong attractive interactions, where the range and magnitude decrease with liquid surface tension. Comparison of free energy calculations based on the capillary menisci shapes and the force measurements suggest that under our dynamic measurements the gas pressure in the capillary is slightly below ambient.
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| 4. |
- Karlsson, Patrik, 1973-, et al.
(författare)
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Galling resistance evaluation of tool steels by two different laboratory test methods for sheet metal forming
- 2012
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Ingår i: Lubrication Science. - : John Wiley & Sons. - 0954-0075 .- 1557-6833. ; 24:6, s. 263-272
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Tidskriftsartikel (refereegranskat)abstract
- Adhesive accumulation of work material on the tool surface is today a major problem in many sheet metal-forming applications. Different laboratory test methods are used to investigate galling with respect to different tool materials, lubricants and process conditions. In the present study, the galling resistance of a modern nitrogen-alloyed powder metallurgy tool steel and an conventional ingot cast D2 type tool steel was evaluated under lubricated sliding against ferritic stainless steel sheets using a commercial pin-on-disc (POD) and an in-house made slider-on-flat-surface (SOFS) tribotester. The investigated tool steels ranked similarly in terms of galling resistanc in both test methods. However, sliding distances to galling were longer for the SOFS equipment due to continuous sliding on new lubricated sheet surface. Best performance was demonstrated by the powder metallurgy tool steel treated to 65 HRC. Differences in friction behaviour and galling initiation were analysed on the basis of the two different working conditions, i.e. open (SOFS) and closed (POD) tribosystems. Copyright © 2012 John Wiley & Sons, Ltd.
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| 6. |
- Vessby, Johan, 1976-, et al.
(författare)
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Structural use of cut-offs from clt-production – three examples that utilize the unique properties
- 2023
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Ingår i: World Conference on Timber Engineering WCTE 2023. - : World Conference on Timber Engineering 2023 (WCTE 2023). - 9781713873297 - 9781713873273 ; , s. 139-146
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Konferensbidrag (refereegranskat)abstract
- Production of CLT-panels typically results in 5-10% cut-offs due to window and door openings. CLT-boards can be made by slicing these cut-offs and finger-jointing them. It is worth while from economic and climatic aspects to find applications for such boards as building products with long service life. It is preferred to find uses where the premium transverse properties are utilized. This paper present three novel ideas for re-use of cut-offs from CLT. (a) The re-use as REX laminations in CLT production is a smart concept that minimize waste in an economical way. (b) By using finger-jointed CLT-boards as horizontal rails in timber frame buildings, the problems with over-load and deformations in multi-storey houses are minimized. (c) The capacity of glulam beams to carry concentrated loads is greatly enhanced by integrating CLT-boards as laminations.
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