The huge variety of wood species and wood-based products allows a wide scope of creative and aesthetic alternatives to materials with higher environmental impacts during production, use and disposal. The high ratio between strength and own weight recommends wood also for load bearing applications. Therefore, the use of wood can assure sustainability in the building trade as well as in many other sectors. However, the positive aspect of biological decomposability of waste wood can turn into the opposite when wood is used outdoors and exposed to different degrading organisms. Protective measures are therefore unavoidable for many outdoor applications. The most common way to respond to these shortcomings was the impregnation of less durable wood species with biocidal agents or the use of more durable species, which normally means the use of tropical species. Both options usually stand in contrast to the desired eco-friendliness of wood-based products. In contrast to classic wood preservation techniques, which are increasingly refused by customers, innovative and non-biocidal wood treatments possibilities found acceptance. In his respective project three approaches will be targeted. Namely, treatment of wood with selected hydrophobic treatments, wood modification and use of durable species like oak, chestnut, larch. Resistance of wood as well as of modified and preservative treated timber against different wood-discolouring and wood-destroying organisms is always a combined effect of toxic or inhibiting ingredients on the one hand, and of anatomical or chemical exclusion of moisture, which is one of the most important factors for biodeterioration. In this research natural moisture exclusion efficacy was compared to artificial one (at specimens treated with hydrophobic treatments or modified wood). Nevertheless, most studies in the past have allowed for only one of these protection mechanisms, but not for both and potential synergisms to be expected. Thus, even in this respect a more comprehensive approach is needed to consider the full range of wood properties.
COBISS.SI-ID: 2204809
Xylem and phloem formation, as well as cambium and leaf phenology and their relation to weather factors were studied in beech (Fagus sylvatica L.) trees from two sites in Slovenia with different elevations and weather conditions. We described and explained main differences in these phenomena for trees growing in different environments where variable year to year conditions affect the amount and quality of wood and phloem formed in a particular year in this important tree species. There were several articles published on the selected topic. They are resolved from the list below: ČUFAR, Katarina, GRABNER, Michael, MORGÓS, András, MARTINEZ DEL CASTILLO, Edurne, MERELA, Maks, DE LUIS, Martin. Common climatic signals affecting oak tree-ring growth in SE Central Europe 2007. Trees, ISSN 0931-1890, 2014, str.[COBISS.SI-ID 2171785] PRISLAN, Peter, GRIČAR, Jožica, DE LUIS, Martin, SMITH, Kevin T., ČUFAR, Katarina. Phenological variation in xylem and phloem formation in Fagus sylvatica from two contrasting sites. Agricultural and forest meteorology, ISSN 0168-1923. [Print ed.], 2013, vol. 180, no. oct., str. 142-151.[COBISS.SI-ID 2115465] ROSSI, Sergio, ČUFAR, Katarina, GRIČAR, Jožica, PRISLAN, Peter, et al. A meta-analysis of cambiumphenology and growth : linear and non-linear patterns in conifers of the northern hemisphere. Annals of Botany, ISSN 0305-7364, 2013, vol. (v tisku), no. (v tisku), str. (v tisku), ilustr. [COBISS.SI-ID 3728806] DE LUIS, Martin, ČUFAR, Katarina, DI FILIPPO, Alfredo, NOVAK, Klemen, et al. Plasticity in dendroclimatic response across the distribution range of aleppo pine (Pinus halepensis). PloS one, ISSN 1932-6203, 2013, vol. 8, no. 12, str. 1-13, [COBISS.SI-ID 2171273]
COBISS.SI-ID: 2115465
Low-density hybrid poplar was densified with viscoelastic thermal compression (VTC) process to achieve 63 %, 98 % and 132 % degree of densification. The morphology and density profile of the VTC specimens were studied. Microscopic observation revealed that the deformations in the VTC wood were mostly the result of the viscous buckling of cell walls without fracture. The volume of the void areas in the specimens decreased with the degree of densification. It was confirmed that low-density wood species modified by VTC can be successfully used for the production of wood-based composites. Besides this manuscript there were some other manuscripts published on the same topic as well: KUTNAR, Andreja, HUMAR, Miha, KAMKE, Frederick A., ŠERNEK, Milan. Fungal decay of viscoelastic thermal compressed (VTC) wood. Holz als Roh- und Werkstoff, ISSN 0018-3768. [Print ed.], 2011, vol. 69, no. 2, str. 325-328, doi: 10.1007/s00107-010-0432-z. [COBISS.SI-ID 1024255060] LESAR, Boštjan, HUMAR, Miha, KAMKE, Frederick A., KUTNAR, Andreja. Influence of the thermo-hydro-mechanical treatments of wood on the performance against wood-degrading fungi. Wood Science and Technology, ISSN 0043-7719, 2013, vol. 47, iss. 5, str. 977-992, doi: 10.1007/s00226-013-0553-8. [COBISS.SI-ID 1024510548] RAUTKARI, Lauri, LAINE, Kristiina, KUTNAR, Andreja, MEDVED, Sergej, HUGHES, Mark. Hardness and density profile of surface densified and thermally modified Scots pine in relation to degree of densification. Journal of Materials Science, ISSN 0022-2461, 2013, vol. 48, no. 6, str. 2370-2375, doi: 10.1007/s10853-012-7019-5. [COBISS.SI-ID 1024475220] UGOVŠEK, Aleš, KAMKE, Frederick A., ŠERNEK, Milan, PAVLIČ, Matjaž, KUTNAR, Andreja. The wettability and bonding performance of densified VTC beech (Fagus sylvatica L.) and Norway spruce (Picea abies (L.) Karst.) bonded with phenol-formaldehyde adhesive and liquefied wood. Holz als Roh- und Werkstoff, ISSN 0018-3768. [Print ed.], 2013, vol. 71, no. 3, str. 371-379, doi: 10.1007/s00107-013-0669-4. [COBISS.SI-ID 1024488788],
COBISS.SI-ID: 1655177
The research on the industrial production of pinosylvins and NTG from knots of pines showed aplicable conclusions. The composition of the extracts was determined by GC, GCMS, HP-SEC. The main phenolic compounds are the stilbenes pinosylvin and its monomethyl ether and the lignan nortrachelogenin (NTG), and their amounts vary a lot from sample to sample. The sequential extraction with a nonpolar solvent as a first step for removing the lipophilic compounds was the most efficient approach for the recovery of both pinosylvins and NTG. For food applications, hot water and 85% aqueous ethanol were good solvents for the production of the substances in focus. Besides this manuscript there were some other manuscripts published on the same topic as well: VEK, Viljem, OVEN, Primož, POLJANŠEK, Ida. Content of total phenols in red heart and wound-associated wood in beech (Fagus sylvatica L.) = Sadržaj ukupnih fenola u crvenom srcu i ranjenom dijelu drva bukve (Fagus sylvatica L.). Drvna industrija, ISSN 0012-6772, 2013, let. 64, št. 1, str. 25-32. [COBISS.SI-ID 2091657] VEK, Viljem, OVEN, Primož, POLJANŠEK, Ida. Quantitative HPLC analysis of catechin in wound-associated wood and knots of beech = Kvantitativna HPLC analiza katehina u ranjenom dijelu i kvrgama bukova drva. Drvna industrija, ISSN 0012-6772, 2013, let. 64, št. 3, str. 231-238. [COBISS.SI-ID 2138249] VEK, Viljem, OVEN, Primož, HUMAR, Miha. Phenolic extractives of wound-associated wood of beech and their fungicidal effect. International biodeterioration & biodegradation, ISSN 0964-8305. [Print ed.], 2013, vol. 77, no. 2, str. 91-97. [COBISS.SI-ID 2079369]
COBISS.SI-ID: 2134665
Waxes and wax emulsions are one of the most important solutions for non-biocidal wood protection. Wax treated wood is designed for outdoor use, therefore it is of considerable importance to elucidate the influence of weathering on the photodegradation processes. It is presumed, that wax treatment will reduce water uptake and thus reduce or slow down photodegradation processes. In order to test this hypothesis, three types of wax emulsions at two different concentrations were vacuum impregnated into Norway spruce wood specimens: an emulsion of montan wax (LGE), an emulsion of polyethylene (WE1) and an emulsion of oxidized polyethylene (WE6) wax. The samples were exposed to artificial accelerated weathering (AAW) for 500 cycles. Before and after AAW colour, the contact angle of water and moisture content were determined. Chemical and morphological changes at exposed surfaces were also investigated with FTIR spectroscopy and SEM. In parallel, the uptake of wax emulsions and water into the axial surfaces of samples was determined with a tensiometer. The moisture content measurements showed that the best hydrophobic effect was achieved with LGE treated wood, where the lowest colour and FTIR changes were observed as well. These results were supported by tensiometer measurements as well. Presented data clearly showed that high loadings of waxes reduce or at least slow down weathering. Among tested waxes, montan wax was found the most effective.
COBISS.SI-ID: 1914761