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Wood fibre insulation material
2016
Veitmans, K., Latvia Univ. of Agriculture, Jelgava (Latvia) | Grinfelds, U., Latvian State Inst. of Wood Chemistry, Riga (Latvia)
As worldwide trends are changing gradually and sustainable resources economy and reduction of hazardous emissions are coming to the forefront, several industry sectors are forced to revalue their resource consumption. The main emphasis is currently placed on the recycling of by-products. One of the methods, definitely, includes burning of by-products to generate power, however it is not always the most efficient one. By-products must be used in the manner that ensures that they provide high added value for the operation of the company and are environmentally friendly. This research focuses on the use of the by-products of birch (Betula) veneer manufacturing, in order to obtain thermal insulation material. The following characteristics of the wood fibre insulation material were determined: thermal conductivity, water absorption, vapour permeability, and prototype reaction to fire. The characteristics of the obtained wood fibre thermal insulation material: thermal conductivity 0.038 W•mE-1•kE-1; water absorption 12 kg•mE-2; the conformity of the material even to D fire reaction class was not determined. The principal conclusion: the wood fibre thermal insulation material conforms to the requirements set for thermal insulation materials.
显示更多 [+] 显示较少 [-]Development trends in the national economy sectors in the Baltic States in 2005-2015
2017
Supe, L., Riga Technical Univ. (Latvia) | Jurgelane, I., Riga Technical Univ. (Latvia)
The processes of globalization in the world economy have a significant impact on different processes and development in all national economy sectors. Innovations and technological development have also increased the competition between economic operators. Faster growth is also observed in service industries. The global economic downturn affected the Baltic States whose development suffered a sharp decline at the end of 2008 and in 2009. A sudden drop in the demand in export markets, as well as the decline in the demand in the domestic markets due to low purchasing power contributed to the deterioration of the economic situation in the Baltic States, particularly in the manufacturing and construction sectors. Starting from 2011, the economic indicators in the Baltic States have been growing and here the export of goods and services can be mentioned as the main contributor to the development of the economy in the Baltic States. Significant changes in the development of economic sectors started in 2013 due to Russia’s economic problems. During the period 2005 – 2015, most of the value added to the overall structure of the national economy in all three Baltic States was brought by trade and manufacturing. The aim of the research is to analyse the national economy sectors in the Baltic States during the period 2005 – 2015 in order to determine processes that affected the development of economy sectors in each of the countries, or the opposite – the recession, thus finding the most competitive sector of the national economy of the Baltic States.
显示更多 [+] 显示较少 [-]The impact of feed rollers on the quality of timber in the manufacturing of posts
2017
Zimelis, A., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Lazdins, A., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Abele, A., Latvia Univ. of Agriculture, Jelgava (Latvia)
The aim of the study was to determine the impact of the harvester cutting head feed roller type on the mechanical damages of processed roundwood timber in post manufacturing. The study presents the comparison of the gentle Moipu plate wheel rollers and conventional feed rollers having bigger spikes (hereinafter named - conventional feed rollers). The total amount of segments processed with the gentle Moipu plate wheel rollers was 2199, whereas the amount of segments processed using the conventional feed rollers was 5308. When processing roundwood with the gentle feed rollers, in the 1st flow 8.2% of timber was rejected as substandard due to defects. The corresponding figure in the 2nd flow was 5.2% of the material in which the damage in the form studs was caused by the feed rollers. When processing the timber with conventional feed rollers, the percentage of the damage – dents caused by these rollers in the 1st flow was 26.7%, in the 2nd flow – 43.7% and in the 3rd flow only 2.7%. Using the method of characteristics proportion comparison, significant differences have been observed between feed rollers (t = 17.8 is greater than t sub(0.05;∞) = 1.96).
显示更多 [+] 显示较少 [-]Manufacturing and application studies of Sots pine bark pellets
2015
Spalvis, K., Latvian State Forest Research Inst. Silava, Salaspils (Latvia);Latvia Univ. of Agriculture, Jelgava (Latvia) | Daugavietis, U., Latvian State Forest Research Inst. Silava, Salaspils (Latvia)
This paper describes the use of Scots pine (Pinus sylvestris L) bark humus and fine fractions for animal litter pellet manufacture, and the efficacy of various additives in improving absorbency. In Latvia is no researches about litter pellet manufacture of pine bark, and possibilities of increasing water absorbency; in internationals research papers there is also no information about the possibilities of improving water absorbency of pine bark pellets with various additives. The additives tested were fresh and fallen leaves, tree needles, dried hogweed and sawdust. Pellets were manufactured with a ZLSP200B granulator at Adazi city, Latvia, in 2014. The results indicated that production of small diameter pine bark pellets could be problematic. Absorbency of the pellets was tested both by rinsing and soaking the pellets, and results were compared to woodchip particle litter pellets. It was found that the best absorbency was achieved with adding up to 30% sawdust, which increased pellet absorbency both by rinsing and soaking. The results indicate that it is possible to manufacture pellets using Scots pine (Pinus sylvestris L.) bark humus and fine fraction with good absorbency which can be disposed of in sewerage systems.
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