10 research outputs found

    Sött och salt

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    Sött och salt – Innehållsförteckning: – Inledaren: På tröskeln till havets decennium / Cecilia Lundberg – Om vatten på öar / Christian Pleijel – Grundvattnet i skärgården / Egon Nordström – Utö gör sitt eget vatten / Erik Sjöberg – Att mäta vatten – Finlands havsplan skapar förutsättningar för en livskraftig skärgård / Marie Sjölind – Mareld gör havet till stjärnhimmel / Conny Sjöqvist – I Aura å mellan broarna / Tore Lindholm – Kan havtorn bidra till att rädda Skärgårdshavet? / Heikki Kallio – Skärgården i kläm mellan övergödning och klimatförändring / Camilla Gustafsson, Joanna Norkko och Alf Norkko – Landhöjningen – eller historien om vattnet som försvann / Liselott Nyström Forsén – Skärgård och ångare skapade familjeföretag / Thure Malmberg – ”Min ö” är artikelserien för alla nesofiler / Pia Prost – Min ö Björkö / Siv Fagerlund – Hur bobar är din ö? / Christian Pleijel – Skärgårds prenumerantkontakt Anita säger hej då! / Mia Henriksson – Skärinytt – Sista bilde

    Processing and water absorption behavior of foamed potato starch

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    Starch foams were prepared from four types of potato starch using two-step extrusion with an intermediate conditioning step at 53% relative humidity in order to control the moisture content. The moisture content was the driving force for the expansion during the second extrusion. The second extrusion was performed with two different dies in order to achieve differences in porosity of the materials. Glycerol in combination with water was used as plasticizer for the starches. The rheological properties of the melts and the moisture content of the starch materials prior to the expansion were determined. The porosity of the expanded structures was characterized using environmental scanning electron microscopy imaging and density measurements. The absorption capability of the starch-based foams was investigated using aqueous NaCl solutions, and the water uptake of thin starch-based films from humid air was also evaluated. Foams prepared from amylopectin potato starch were found to exhibit the highest porosity, the lowest density, and the greatest absorption capability, both from water and from humid air. Not only the density but also the absorption capability was influenced by the porosity level. \ua9 2010 The Author(s)

    Funktionsprovning av tätskiktsystem förvåtutrymmen 2019

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    Functional testing of waterproofing systems for use behind ceramic tiling based on flexible sheets 2019 Functional testing The result is worse than before. Six (32%) of the nineteen tested waterproofing systems passed the function test without leakage. Thirteen (68%) tests resulted in leakage. This result is worse than that obtained in the previous project in 2016, (1) when eight (40%) of twenty tested waterproofing systems passed the functional test without leakage. There has therefore been some deterioration in the as constructed systems. The result, however, is better than in the project performed in 2014 (2) when only three (15%) of twenty tested waterproofing systems passed without leakage. In this project, several leakages are localised around the penetrations of large and small drainpipes. This is an increase compared to previous studies. We have seen on several occasions that pipe collars have had poor quality. This has been noticed by that the polymer material used for sealing around the tube has lost its water tightness ability during the test. It is most probable that the material has a residual deformation (from setting) that causes the material to lose its ability to seal around the tube. We have also noted that the pipe collars have delaminated i.e. the layers in the collars have been divided into their individual constituents during the test. Leakages have also been caused by connections to gullies, inside corners, outside corners and in joints of foils. Fortunately, none of the investigative systems showed leakage that was so extensive that one could describe it as total damage. Water vapour resistance and mass per unit area Thirteen tested waterproofing on flexible sheet systems show a result between 2,5 and 4,5 million s/m, which is a high or very-high water vapour resistance. Six flexible sheet systems have a result below 2,5 million s/m. In the determination of water vapour resistance and mass per unit area, we can clearly see that some manufacturers have made changes in or replaced their flexible sheet with a new one, compared with the previous investigation (1). We further note that 10 out of 14 flexible sheets have a lower water vapor resistance than in the previous investigation (1). It is also notable that the PVC sealing layer has a low water vapor resistance. Indication of long-term properties In order to obtain an indication of the amount added antioxidants that improves the long-term properties of the materials, the DSC analysis of flexible sheets have been performed. In the same way as in the previous project, 2016, (1) it seems that the flexible sheets to be more stabilized for long-term use compared to the previous study in 2014, (2). However, for all analysed materials, to make a reliable service life prediction of the material, an accelerated ageing at moderate temperature is recommended

    Funktionsprovning av tätskiktsystem för våtutrymmen 2022

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    Functional testing of waterproofing systems for use behind ceramic tiling based on flexible sheets 2022 This research project is a repetition of previously completed projects. These projects span a long period of time, 12 years. The projects were completed during the period 2010 to 2022. Functional testing The result is better than before. 2022 2019 (1) 2016 (2) 2014 (3) 2010 (4) Result Result Result Result Result Result No leakage 9 (47 %) 6 (32 %) 8 (40 %) 3 (15 %) 0 (0 %) Leakage 10 (53 %) 13 (68 %) 12 (60 %) 17 (85 %) 5 (100 %) In this investigation, most of the leaks are located to penetrations of large and small sewer pipes. In this investigation, we have on several occasions seen that the pipe sleeves have had substandard quality. This has manifested itself in the fact that the polymeric material which is to seal around the pipe during the test has lost its sealing ability. It is probable that the material has developed a residual deformation (settling) which means that the material has lost its ability to seal around the pipe. We have also noticed that pipe cuffs have delaminated, the layers in the cuff during the test have been divided into their components. Leakage has also occurred at inner corners, outer corners and at chafing. Only a few, two, leaks at connections to floor drains have been noted. Better yet, none of the examined waterproofing systems showed leaks that were so extensive that one can speak of a total damage. Water vapour resistance and mass per unit area The vast majority of investigated waterproofing foils have a water vapour resistance of between 2.5 and 4.5 million s m, which is a high or very high value. Results for five waterproofing foils fall below 2.5 million s / m. Based on the determinations of water vapor resistance and basis weight, it can be concluded that probably six of the waterproofing suppliers have developed new or changed foils since the last survey. The trend of wanting to make thinner foils seems to have been broken. Most of the waterproofing foils have a higher vapor passage resistance now than in the previous survey. It is also noteworthy that the PVC sealing layer has a low water vapor passage resistance. The waterproofing foil has basically the same basis weight now compared to the previous survey. Indication of long-term properties To obtain an indication of the amount of added antioxidants that improve the long-term properties of the materials, DSC analyses of the waterproofing foils have been performed. Compared with the previous study, the induction temperatures are at about the same level as before, only small differences occur. The average induction temperature for all polyethylene films is 216 ° C and, in summary, the materials appear to be stabilized at the same level as the previous study. In the same way as in the survey, 2016, most materials seem to be more stabilized for long-term use compared with the previous study, 2014. However, for all analysed materials, to make a reliable service life prediction of the material, a more comprehensive aging study is recommende

    Funktionsprovning av tätskiktsystem för våtutrymmen 2022

    No full text
    Functional testing of waterproofing systems for use behind ceramic tiling based on flexible sheets 2022 This research project is a repetition of previously completed projects. These projects span a long period of time, 12 years. The projects were completed during the period 2010 to 2022. Functional testing The result is better than before. 2022 2019 (1) 2016 (2) 2014 (3) 2010 (4) Result Result Result Result Result Result No leakage 9 (47 %) 6 (32 %) 8 (40 %) 3 (15 %) 0 (0 %) Leakage 10 (53 %) 13 (68 %) 12 (60 %) 17 (85 %) 5 (100 %) In this investigation, most of the leaks are located to penetrations of large and small sewer pipes. In this investigation, we have on several occasions seen that the pipe sleeves have had substandard quality. This has manifested itself in the fact that the polymeric material which is to seal around the pipe during the test has lost its sealing ability. It is probable that the material has developed a residual deformation (settling) which means that the material has lost its ability to seal around the pipe. We have also noticed that pipe cuffs have delaminated, the layers in the cuff during the test have been divided into their components. Leakage has also occurred at inner corners, outer corners and at chafing. Only a few, two, leaks at connections to floor drains have been noted. Better yet, none of the examined waterproofing systems showed leaks that were so extensive that one can speak of a total damage. Water vapour resistance and mass per unit area The vast majority of investigated waterproofing foils have a water vapour resistance of between 2.5 and 4.5 million s m, which is a high or very high value. Results for five waterproofing foils fall below 2.5 million s / m. Based on the determinations of water vapor resistance and basis weight, it can be concluded that probably six of the waterproofing suppliers have developed new or changed foils since the last survey. The trend of wanting to make thinner foils seems to have been broken. Most of the waterproofing foils have a higher vapor passage resistance now than in the previous survey. It is also noteworthy that the PVC sealing layer has a low water vapor passage resistance. The waterproofing foil has basically the same basis weight now compared to the previous survey. Indication of long-term properties To obtain an indication of the amount of added antioxidants that improve the long-term properties of the materials, DSC analyses of the waterproofing foils have been performed. Compared with the previous study, the induction temperatures are at about the same level as before, only small differences occur. The average induction temperature for all polyethylene films is 216 ° C and, in summary, the materials appear to be stabilized at the same level as the previous study. In the same way as in the survey, 2016, most materials seem to be more stabilized for long-term use compared with the previous study, 2014. However, for all analysed materials, to make a reliable service life prediction of the material, a more comprehensive aging study is recommende
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