| 1. |
- Bolmsjö, Gunnar, et al.
(författare)
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Task Programming of Welding Robots
- 1995
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Ingår i: Proceedings of the International Conference on the Joining of Materials, JOM-7. ; , s. 573-585
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Konferensbidrag (refereegranskat)
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| 2. |
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| 3. |
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| 4. |
- Engström, Johan, et al.
(författare)
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Method and device for the continuous cooking of pulp
- 1998
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Patent (populärvet., debatt m.m.)abstract
- This invention relates to a new and improved way of continuously cooking fibre material, wherein temperatures and alkaline levels are controlled to be maintained within specific levels in different zones of the digesting process in order to optimise chemical consumption and heat-economy and at the same time achieve very good pulp properties. The fibre material is heated and impregnated by the aid of black liquor to a temperature less than 140 .degree.C and passed in con- current in an impregnation zone (A). The heated and impregnated fibre material is transferred to a con-current cooking zone (B) in the upper part of a digester (6). At least 60 % of the quantity of liquor (F) required for the cooking reaction is supplied in the up-stream end of the con- current cooking zone (B) in order to obtain a level of effective alkali exceeding 35 g/l.; The cooking temperature in the con-current cooking zone (B) is lower than 160 .degree.C. Spent liquor (E), with an amount of effective alkali of at least 13 g/l, is withdrawn from a strainer girdle (8). A substantial part of the spent liquor is supplied to the impregnation zone.
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| 5. |
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| 6. |
- Holmberg, Krister, et al.
(författare)
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Surface modification of hydroxyapatite for dental plaque inhibition
- 1997
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Ingår i: Functional Polymers Syntheses and Applications. - : American Chemical Society (ACS). ; , s. 739-751
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Bokkapitel (refereegranskat)abstract
- Various types of surface treatments of hydroxyapatite have been investigated in order to obtain a material with low protein and bacterial adsorption characteristics. Since hydroxyapatite is seen as a model for tooth enamel, a procedure providing a surface with low tendency for biofouling would be of interest in vivo to prevent build-up of dental plaque. The paper summarizes surface modification work in the area, including treatments with proteins and polyelectrolytes, use of hydrophilic noncharged polymers, modification with silicones and fluorination. Particularly interesting in vitro results have been obtained with hydrophilic polymers, e.g. poly(alkylene oxides) and polysaccharides, carrying phosphate groups for anchoring to the mineral surface.
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| 7. |
- Johansson, Bengt, et al.
(författare)
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Combustion Chambers for Natural Gas SI Engines Part I: Fluid Flow and Combustion
- 1995
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Ingår i: SAE Transactions, Journal of Engines. - 0096-736X. ; 104:SAE Technical Paper 950469
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Tidskriftsartikel (refereegranskat)abstract
- The most economical way to convert truck and bus DI-diesel engines to natural gas operation is to replace the injector with a spark plug and modify the combustion chamber in the piston crown for spark ignition operation. The modification of the piston crown should give a geometry well suited for spark ignition operation with the original swirling inlet port. Ten different geometries were tried on a converted VOLVO TD102 engine and a remarkably large difference in the rate of combustion was noted between the chambers. To find an explanation for this difference a cycle resolved measurement of the in-cylinder mean velocity and turbulence was performed with Laser Doppler Velocimetry (LDV). The results show a high correlation between in cylinder turbulence and rate of heat release in the main part of combustion. The very early part of combustion is more affected by other parameters but the intermediate part of combustion corresponding to 0.5-10% of the total heat released is influenced by both mean velocity and turbulence. There is a surprisingly good correlation between the average level of turbulence and the used squish area.
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| 8. |
- Olsson, Krister, et al.
(författare)
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Combustion Chambers for Natural Gas SI Engines Part 2: Combustion and Emissions
- 1995
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Ingår i: SAE Transactions, Journal of Engines. - 0096-736X. ; 104:SAE Technical Paper 950517
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Tidskriftsartikel (refereegranskat)abstract
- The objective of this paper is to investigate how the combustion chamber design will influence combustion parameters and emissions in a natural gas SI engine. Ten different geometries were tried on a converted Volvo TD102 engine. For the different combustion chambers emissions and the pressure in the cylinder have been measured. The pressure in the cylinder was then used in a one-zone heat-release model to get different combustion parameters. The engine was operated unthrottled at 1200 rpm with different values of air/fuel ratio and EGR. The air/fuel ratio was varied from stoichiometric to lean limit. EGR values from 0 to 30% at stoichiometric air/fuel ratio were used. The results show a remarkably large difference in the rate of combustion between the chambers. The cycle-to-cycle variations are fairly independent of combustion chamber design as long as there is some squish area and the air and the natural gas are well mixed. Geometries that give the fastest combustion give the highest NOx values at l=1.2, but at l>1.5, which is normally designated lean-burn, the differences are smaller. The lowest NOx values for lean burn were obtained with the geometries that gives fast combustion. The HC emissions display some correlation between high combustion rate and low levels of HC emissions, but combustion chambers with dead zones and large total combustion chamber areas give higher HC contents than the combustion rate alone would indicate. Indicated efficiency is reduced for combustion chambers with a large total combustion chamber surface area and thus large heat losses. High levels of turbulence also tend to reduce the efficiency for the same reason.
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| 9. |
- Snekkens, Vidar, et al.
(författare)
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Method for precipitating hemicellulose onto fibres for improved yield and beatability : Förfaringssätt för utfällning av hemicellulosa på fiber för förbättrat utbyte och malbarhet
- 1998
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Patent (populärvet., debatt m.m.)abstract
- A method for continuous cooking of lignocellulosic fibre material, comprising the steps of sequentially (a) in a first stage, impregnating the fibre material in an impregnation liquid comprising alkali metal hydroxide, and thereafter withdrawing (14, 514) a spent impregnation liquid; (b) in a second stage, cooking the fibre material in a cooking liquor comprising alkali metal hydroxide; and (c) in a third stage, adding (A), to said fibre material, a liquid which is rich in hemicellulose, said liquid preferably comprising at least a part (14a, 514a) of said withdrawn spent impregnation liquid. In a fourth stage (d), the fibre material is cooked in a cooking liquor comprising the liquid added in the third stage, whereby the fibre material is subjected to a retention time of at least 1 hour in said fourth stage.
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| 10. |
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