| 1. |
- Andersson, Agneta, et al.
(författare)
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Domiciliary liquid oxygen versus concentrator treatment in chronic hypoxaemia: a cost-utility analysis
- 1998
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Ingår i: European Respiratory Journal. - 1399-3003. ; 12:6, s. 1284-1289
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Tidskriftsartikel (refereegranskat)abstract
- Whether long-term oxygen therapy (LTOT) improves quality of life in chronic hypoxaemia has been questioned. LTOT with an oxygen concentrator (C/C) and gas cylinders for ambulation is considered cumbersome compared to mobile liquid oxygen equipment (L). The hypothesis for this study was that LTOT with liquid oxygen treatment (L) improves patients' health-related quality of life, but that it is also more expensive compared to concentrator (C/C) treatment. A prospective, randomized multicentre trial comparing C/C with L for LTOT was conducted during a six-month period. Fifty-one patients (29 on L and 22 on C/C) with chronic hypoxaemia, regularly active outside the home, participated in the study initially. Costs for oxygen were obtained from the pharmacies. Patient diaries and telephone contacts with members of the healthcare sector were used to estimate costs. Health-related quality of life was measured by the Sickness Impact Profile (SIP) and the EuroQol, instruments at the start and after 6 months. The average total cost per patient for group C/C for the six-month period was US$1,310, and for group L it was US$4,950. Health-related quality of life measured by the SIP instrument showed significant differences in favour of group L in the categories/dimensions of physical function, body care, ambulation, social interaction and total SIP score. In conclusion, liquid-oxygen treatment was more expensive compared to concentrator treatment. However, treatment effects showed that liquid oxygen had a better impact on quality of life.
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| 2. |
- Dahlvik, P, et al.
(författare)
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Interactions in coating colours induced by a thermally active cellulosic polymer
- 1999
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Ingår i: Journal of Pulp and Paper Science (JPPS). - 0826-6220. ; 25, s. 229-234
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Tidskriftsartikel (refereegranskat)abstract
- A thermally active polymer, ethyl hydroxyethyl cellulose (EHEC), was evaluated with respect to its ability to generate temperature-induced interactions between components in coating colors. At low temperatures the polymer is water soluble, providing a good flow behavior to the color. As the temperature is raised a phase separation of the polymer takes place, inducing an interaction between the components in the color. Rheological measurements showed that using EHEC as thickener resulted in a significant temperature-induced viscosity increase of the coating color. The increase in viscosity was found to be a result of interactions taking place between the three-component system consisting of EHEC, latex and pigment. The increase in viscosity with increasing temperature was further shown to correlate with the styrene/butadiene ratio in the latex. It was also found that a higher amount of EHEC was adsorbed on English clay than on ground calcium carbonate. This affected the degree of interaction within the three-component system EHEC-latex-pigment, in that the increase in viscosity with temperature was lower when English clay was used. However, when delaminated US clay was used, a strong temperature effect was detected.
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| 3. |
- Dahlvik, P, et al.
(författare)
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Variations in calcium ion concentration and pH influencing coating colour rheology, dewatering and immobilization
- 1997
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Ingår i: Nordic Pulp & Paper Research Journal. - 0283-2631 .- 2000-0669. ; 12, s. 61-66
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Tidskriftsartikel (refereegranskat)abstract
- Interparticle interactions in a coating colour are largely influeced by electrolyte concentration and suspension pH. The degree of interaction is reflected in the rheological and dewatering properties of the colour as well as in the structural properties of the immobilized coating layer. In the present study an attempt is made to correlate the degree of interparticle interaction created within coating colours by variation in calcium ion concentration and pH with the atomic absorption spectroscopy were applied to gain further information about the degree of interaction. Results showed that coating colours of a mix of calcium carbonate and clay exhibit a pronounced elastic character. The elastic response increased with calcium ino concentration. This is due to calcium calcium ions binding to the dispersing agent, making it less effective. A further cauce is the decrease in the thickness on the diffuse layer of counter ions surrounding the pigment particles. A pH-reducation further strenghened the created intrinsic three-dimensional network structure. An increase in calcium ion concentration resulted in a reduced water retention, slightly pronounced by a higher pH. The immobilization solids content as did also a lower pH. Characterization of coated layers drawn down on polyester film confirmed that a combination of a high calcium ion concentration and a reduction of pH results in a pronounced pigment interaction, reflected in a thicker layer with lower density and higher roughness.
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| 4. |
- Grön, J, et al.
(författare)
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Influence of starch modification on the chemical composition and structure of coated layers
- 1998
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Ingår i: Nordic Pulp & Paper Research Journal. - 0283-2631 .- 2000-0669. ; 13, s. 119-123
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Tidskriftsartikel (refereegranskat)abstract
- Colloid interactions in clay coating colors have benn modified with either an anionic or a cationized starch cobinder. This paper reports on surface chemistry and structure of the coated papers as well as print gloss and ink demand. The thickness of the surface layer and the top layer of the coating was defined by the analyzing equipment and was about 0.01μm and a few μm respectively. The internal structure of the coating layer was characterized with air leak porous layer structure. These coatings also had much higher amounts of starch in the surface layer, while the coatings containig anionic starch had a higher content of latex in the top layer. The ink requirement to reach a certain print gloss was higher for the aggregated coatings i.e. those containing cationized starch. A higher ink demand was initiated by a more porous layer structure and a rougher surface.
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| 5. |
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| 6. |
- Ström, G, et al.
(författare)
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A novel formulation approach for improving fibre coverage during blade coating
- 1995
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Ingår i: Nordic Pulp & Paper Research Journal. - 0283-2631 .- 2000-0669. ; 10, s. 227-233
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Tidskriftsartikel (refereegranskat)abstract
- It is generally understood that increased pigment aggregation and structuring of wet coating colour improves fibre coverage, but reduces runnability on the blade coater. This paper presents a formulation approach which results in formation of a significant coating structure only after the blade. The approach is based on the laboratory observation that the structuring effect of small amounts of a salt is inversely dependent on coating colour pH. The combination of calcium chloride addition and the use of ammonia for pH control is therefore proposed. The evaporation of ammonia after the blade results in pH reduction and allows the formation of pigment structure during coating consolidation. Results from laboratory studies and pilot coater trials are presented. The latter suggest that the proposed approach provides significant improvements in fibre coverage, surface smoothness and opacity, but that surface strength is reduced. Laboratory results and the observed good blade runnability indicate that the coating structuring is obtained only after the blade, as the ammonia evaporates.
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