| 1. |
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Ion, John, et al.
(författare)
-
Process diagrams for laser beam welding of carbon manganese steels
- 1996
-
Ingår i: Welding Journal. - 0043-2296. ; 75:7, s. 225-
-
Tidskriftsartikel (refereegranskat)abstract
- Diagrams are presented which illustrate the ranges of process variables that can be used to produce acceptable laser welds in carbon manganese steels. The most practical type uses axes of beam power and welding speed. An empirical operating window is displayed, which describes the limits of full joint penetration welding for a particular steel and plate thickness. Theoretical contours of heat-affected zone (HAZ) hardness, established using analytical models, are also displayed on the diagram. Appropriate combinations of laser beam power and welding speed can thus be selected. A more comprehensive diagram uses axes of carbon equivalent and absorbed laser beam energy, on which theoretical HAZ hardness contours are displayed. The effects of changes in steel composition and welding variables on HAZ hardness can thus be assessed. Model results agree well with experimental data, as well as more sophisticated predictive methods. The diagrams provide guidance on the selection of steel composition and beam parameters during the initial stages in the development of procedures for laser welding of carbon manganese steels.
|
|
| 5. |
|
|
| 6. |
- Ohrvall, M, et al.
(författare)
-
The serum cholesterol ester fatty acid composition but not the serum concentration of alpha tocopherol predicts the development of myocardial infarction in 50-year-old men : 19 years follow-up.
- 1996
-
Ingår i: Atherosclerosis. - : Elsevier BV. - 0021-9150 .- 1879-1484. ; 127:1, s. 65-71
-
Tidskriftsartikel (refereegranskat)abstract
- A low serum tocopherol concentration and a low proportion of linoleic acid in plasma cholesterol esters have been reported to be associated with coronary heart disease. This study was undertaken to evaluate the predictive importance of the serum cholesterol ester fatty acid composition and serum tocopherol concentration in addition to established risk factors for myocardial infarction. The study comprised 2322 fifty-year-old men who participated in a health survey in 1970-1973 regarding risk factors for coronary heart disease. The proportions of myristic, palmitic, palmitoleic, and dihomogammalinolenic acid were significantly higher in 1970-1973 in subjects who suffered myocardial infarction during the following 19 years, while the proportion of linoleic acid was lower, than in those who remained healthy. Serum tocopherol did not differ significantly between the groups. LDL/HDL ratio, systolic blood pressure, and arachidonic acid/dihomogammalinolenic acid ratio were significant independent discriminators between cases and controls in a stepwise logistic regression analysis. This study suggests that middle-aged men who later develop a myocardial infarction are characterized not only by conventional risk factors but also by an altered fatty acid composition of serum cholesterol esters, with a low arachidonic to dihomogammalinolenic acid ratio, indicating reduced delta 5 desaturase activity. This may imply that changes in the quality of dietary fat intake, or an altered capacity to metabolize fatty acids in the body, could precede the development of coronary heart disease.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
|
|
| 11. |
- Ström, G, et al.
(författare)
-
A novel formulation approach for improving fibre coverage during blade coating
- 1995
-
Ingår i: Nordic Pulp & Paper Research Journal. - 0283-2631 .- 2000-0669. ; 10, s. 227-233
-
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.
|
|
