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Silva Fennica 1926-1997
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Acta Forestalia Fennica
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Articles containing the keyword 'power'.

Category: Research article

article id 904, category Research article
Raul Fernandez-Lacruz, Fulvio Di Fulvio, Dan Bergström. (2013). Productivity and profitability of harvesting power line corridors for bioenergy. Silva Fennica vol. 47 no. 1 article id 904. https://doi.org/10.14214/sf.904
Trees growing under the wires and around the pylons carrying power lines (PL) represent a significant threat to the power supply because they can cause power outages and damage. The vegetation in these PL corridors is cleared motor-manually on a regular basis, which represents about 50% of the PL maintenance costs. In Sweden, PL corridors account for 140 000 ha of productive forest land, with an estimated bioenergy potential of 3 TWh/year. The aim of this study was to measure the productivity of a harvester (with an accumulating felling head) and a forwarder, performing PL corridor clearing (with the collection of whole trees for energy use) and to calculate how the cost and economic profitability is dependent on tree height, biomass removal, harvested area, forwarding distance and wood fuel price. The study also compared the economic profitability of the mechanized harvesting system with motor-manual clearing. Experimental units were inventoried along a PL corridor in central Sweden and a time study of one harvester and one forwarder (with a single operator per machine), working in those units, was carried out. The results showed that if the tree height was greater than about 6 m, the mechanized harvesting system became a more cost-efficient alternative, when compared to motor-manual clearing, but it was also found that mechanized clearing is not always the most cost-effective option. Nevertheless, mechanization of PL clearing has a huge potential for expansion, requiring further research in the combined management of the PL corridors and side areas.
  • Fernandez-Lacruz, Department of Forest Biomaterials and Technology, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden ORCID ID:E-mail: raul.fernandez@slu.se (email)
  • Di Fulvio, Department of Forest Biomaterials and Technology, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden ORCID ID:E-mail: fulvio.di.fulvio@slu.se
  • Bergström, Department of Forest Biomaterials and Technology, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden ORCID ID:E-mail: dan.bergstrom@slu.se
article id 302, category Research article
Gökay Nemli, Turgay Akbulut, Emir Zekoviç. (2007). Effects of some sanding factors on the surface roughness of particleboard. Silva Fennica vol. 41 no. 2 article id 302. https://doi.org/10.14214/sf.302
Effects of the grit sizes of the sand belt, feeding speed and the feed power of the heads of the sander on the surface roughness of the particleboard panels were investigated. Two surface roughness parameters, average roughness (Ra) and mean peak-to-valley height (Rz), obtained from board surfaces were used in the analysis. Sanding factors were found to have a significant effect on the surface roughness of the particleboard. Better results were obtained with 40 m/min of feeding speed, 40-60-80-120 of grit sizes, and 67 kW of the feed power of the heads of the sander.
  • Nemli, Karadeniz Technical University, Faculty of Forestry, Trabzon-Türkiye ORCID ID:E-mail: nemli@ktu.edu.tr (email)
  • Akbulut, Istanbul University, Faculty of Forestry, Istanbul-Türkiye ORCID ID:E-mail:
  • Zekoviç, Starwood Forest Product Company, Production Manager, Bursa-Türkiye ORCID ID:E-mail:

Category: Article

article id 5148, category Article
A. Hautojärvi, S. Ahonen, R. Erkinjuntti, H.-S. Katainen, T. Lappalainen, T. Raunemaa. (1981). Surface concentration of sulphur on Scots pine needles. Silva Fennica vol. 15 no. 4 article id 5148. https://doi.org/10.14214/sf.a15375

A method to determine sulphur as sulphate has been applied to search for surface concentration of sulphate sulphur on needle samples. The method is based on reducing sulphates as volatile hydrogen sulphide gas by using hydriodic acid. The hydrogen sulphide gas is swept with nitrogen into an absorbent solution. Sulphide ion concentration in solution is then measured using ion selective electrodes.

The method was applied on one to four years old needle samples collected from Scots pine (Pinus sylvestris L.) at 0.9 to 15.9 km distances from a 1,064 MW coal-fired power plant in Southern Finland. Surface sulphate values found in the samples closer than 4 km to the power plant were 50 to 100% higher than a nearly constant background level. No significant variation of values with needle age was found. The advantages of the method compares to other methods for sulphur determination are speed, reasonable sensitivity and low detection limit.

  • Hautojärvi, ORCID ID:E-mail:
  • Ahonen, ORCID ID:E-mail:
  • Erkinjuntti, ORCID ID:E-mail:
  • Katainen, ORCID ID:E-mail:
  • Lappalainen, ORCID ID:E-mail:
  • Raunemaa, ORCID ID:E-mail:
article id 5145, category Article
Torleif Bramryd. (1981). Environmental effects of heavy metals distributed from power plants. Silva Fennica vol. 15 no. 4 article id 5145. https://doi.org/10.14214/sf.a15372

Increased prices on oil have resulted in the search for alternative energy sources, e.g. coal, peat, biomass, different types of waste. Combustion especially of waste, coal and peat emits large quantities of air pollutants such as heavy metals but also harmful organic substances. Heavy metals are not easily separated from the smoke, and the concentrations are often high in the emissions even with advanced fly-ash separators.

Ecological investigations carried out around a coal burning power plant in Finland using mosses and pine needles as parameters are presented in the paper. Increased concentrations of Pb, Cd, Cr, Ni, Cu and V have been found near the plant. Often a clear gradient was found with increased concentrations at decreased distance from the power plant.

  • Bramryd, ORCID ID:E-mail:
article id 4818, category Article
Matti Kärkkäinen. (1970). Moottorisahojen valinnasta teknisten ominaisuuksien ja hinnan perusteella. Silva Fennica vol. 4 no. 2 article id 4818. https://doi.org/10.14214/sf.a14607
English title: The choice of power saws on the basis of the price and technical properties.

This investigation studies the effect of the retail price and the technical properties of preference ordering of buyers of power saw. According to the model derived, the preference ordering of power saws is due to technical properties xj. If no such restrictions in the function are supposed that could have bearing on the preferences of the buyers, there may be N ! possible combinations, when there are N power saws. If one can presume that each price corresponds with a technical level it is possible that each buyer has an optimum price of his own. The bigger the difference between the optimum and actual price, the less preferred the actual power saw is. In this case one may notice the amount of possible orderings is much less than that based on the model. Thus, the mode may be used.

In this paper some models are presented for cases when only n pieces of the population of N power saws are studied. 16 power saws of differing ages and technical levels were investigated. It was noted that many criteria of technical goodness were positively intercorrelated. The price correlated positively with every criterium used. According to the profile analysis, it was concluded that there were many development lines. For example, the idea of a light and the idea of an effective power saw.

According to the principal component analysis, it seemed obvious that there was little room for one- or two-dimensional preference ordering by the technical properties and price.

The PDF includes a summary in English.

  • Kärkkäinen, ORCID ID:E-mail:
article id 4680, category Article
Pohjois-Suomen uitto-olojen järjestelykomitea. (1959). Pohjois-Suomen uitto-olojen järjestelykomitean mietintö. Silva Fennica no. 102 article id 4680. https://doi.org/10.14214/sf.a14123
English title: Report of the organizing committee for timber floating in Northern Finland.

Hydroelectric plants are being planned or already built in Northern Finland. The complete terracing and regulation of watercourses necessary for the power plants will mean great changes in floating conditions and hence for forestry, for which floating is the principal means of transport. Consequently, the Cabinet appointed a committee in 1958 to ascertain the economic, technical and legislative questions connected with timber transport in the area.

The committee has found that about half of the country’s forest area and two thirds of its water power resources are situated in Northern Finland. A prerequisite for the wise utilization of the forest in Northern Finland is an increase in fellings. This can only be put into effect by improving the means of transport, especially the floating channels. The financing required by the organization of floating connected with the building of the hydroelectric power plants amounts to about 10,000 million marks over a period of 20 years.

The committee has suggested that an advisory committee on floating should be established. Its most important task would be to try to produce a general programme for the organization of floating under the changed conditions, and that the State should participate in the expenditure caused by the organization as regards the capital investment needed for changing over to bundle floating.

The PDF includes a summary in English.

  • Pohjois-Suomen uitto-olojen järjestelykomitea, ORCID ID:E-mail:
article id 4680, category Article
Pohjois-Suomen uitto-olojen järjestelykomitea. (1959). Pohjois-Suomen uitto-olojen järjestelykomitean mietintö. Silva Fennica no. 102 article id 4680. https://doi.org/10.14214/sf.a14123
English title: Report of the organizing committee for timber floating in Northern Finland.

Hydroelectric plants are being planned or already built in Northern Finland. The complete terracing and regulation of watercourses necessary for the power plants will mean great changes in floating conditions and hence for forestry, for which floating is the principal means of transport. Consequently, the Cabinet appointed a committee in 1958 to ascertain the economic, technical and legislative questions connected with timber transport in the area.

The committee has found that about half of the country’s forest area and two thirds of its water power resources are situated in Northern Finland. A prerequisite for the wise utilization of the forest in Northern Finland is an increase in fellings. This can only be put into effect by improving the means of transport, especially the floating channels. The financing required by the organization of floating connected with the building of the hydroelectric power plants amounts to about 10,000 million marks over a period of 20 years.

The committee has suggested that an advisory committee on floating should be established. Its most important task would be to try to produce a general programme for the organization of floating under the changed conditions, and that the State should participate in the expenditure caused by the organization as regards the capital investment needed for changing over to bundle floating.

The PDF includes a summary in English.

  • Pohjois-Suomen uitto-olojen järjestelykomitea, ORCID ID:E-mail:

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