Articles containing the keyword 'pihka'

According to the available literature, the appearance of Parana pine (Araucaria angustifolia (Bertol.) Kuntze) wood resembles that of Scots pine (Pinus sylvestris L.). The anatomy is quite different, however. There are no resin canals and fusiform rays with resin canals in Parana pine. They are abundant in Scots pine, however. The basic density of Parana pine is higher. In both species the density increases from the pith outwards, the maximum being reached at the age of 100 years. Compression wood is more common in Parana pine than in Scots pine, and this makes the longitudinal shrinkage of Parana pine greater than that of Scots pine. Otherwise the shrinkage properties do not differ. The mechanical strength is of the same magnitude with the exception of hardness, where Parana pine is superior.

The PDF includes a summary in English.

• Kärkkäinen, E-mail: mk@mm.unknown

In this study the width and height of 1,588 uniseriate and 454 fusiform rays were measured from tangential sections of four Scots pine (Pinus sylvestris L.) trunks. The samples represented various height levels and distances from the pith. The average width of the uniseriate rays was 19.7 μm and that of the fusiform rays, 51.9 μm. The average height of the uniseriate rays was 215.7 μm and that of the fusiform rays 406.2 μm. Due to this difference in height, it may be possible to develop an automatic system for distinguishing between uniseriate end fusiform rays on the basis of their height.

The PDF includes a summary in English.

• Kärkkäinen, E-mail: mk@mm.unknown

The material consists of four Scots pine (Pinus sylvestris L.) stems from which 757 samples were taken from various heights and distances from the pith. According to the results, the number of rays and their sizes are greater at the stump level than higher up in the stem. The size increases, and the number decreases on moving from the pith outwards. However, there are differences between stems as regards the variation model. The ratio between the number of fusiform rays and that of uniseriate rays seems to be lower than anticipated earlier, about 1:40–1:50. The average proportion of ray volume varied from 5.6% to 7.3%.

The PDF includes a summary in English.

• Kärkkäinen, E-mail: mk@mm.unknown

After the Second World War shortage of lubrication oil forced Finland to develop a substitute product that was produced of indigenous materials. This report is an overview of the history of the already terminated lubricating oil industry and it gives a detailed description of lubricating oil production.

The annual lubricating oil consumption in Finland was 15,000 tons before the war, but during the war it decreased to 7-8,000 tons. In 1943 Oy Tervaöljy Ab (Tar Oil Limited) was established with the state of Finland as the main shareholder. It was commissioned to plan and build tar and tar oil plants, and it also transmitted tar from stump wood pyrolyzing plants to oil factories. Two raw materials were used to produce tar oil: tar wood collected from Scots pine (Pinus sylvestris L.) stumps and tall oil, a by-product of sulphate pulp mills. A total of 9,000 tons of lubricating oil substitutes was produced in 1943-1947, 53% of this from sulphate pulp mill by-products and 47% from tar and shale oil.

The PDF includes a summary in English.

• Murto, E-mail: jm@mm.unknown

Systematic resin collection has not been practiced in Finland or other Nordic areas. One reason is the short growing season. Also, the local pine species, Scots pine (Pinus sylvestris L.) gives smaller resin yield than the southern species, such as Pinus maritima. In Nordic boreal forests resin has been collected only in the Soviet Union, where it has been practised also in Eastern Karelia, near the Finnish border. Resin collection experiments were arranged in former resin collection stands in Karelia in 1943. A so-called German method for running resin had been used in the stands. 30-40 sample trees were chosen in five sample sites.

Forest type did not have big influence in the resin yield. The yield seemed to be slightly higher in Scots pine stands growing in fertile sites compared to poorer sites. The diameter of the tree had largest effect on the yield. It is recommended to focus on stands with large trees, and trees with a large, vital crown. In this kind of stands it is possible to get best yield in relation to the work required. The height of the patch that was cut in the stem had no influence on the yield. The size of the patch should, however, not exceed 35-50% of the diameter of the tree.

The PDF includes a summary in German.

• Kalela, E-mail: ek@mm.unknown