Spremembe mehanskih lastnosti lesa zaradi delovanja gliv modrivk : diplomsko delo

Vek, Viljem (author), Humar, Miha (mentor), Bučar, Bojan (reviewer)

Glive modrivke les načeloma samo estetsko razvrednotijo in naj ne bi vplivale na mehanske lastnosti lesa. Da bi to hipotezo potrdili oziroma ovrgli, smo vzorce rdečega bora (0,5 x 1,0 x 20,0 cm) za 2, 4, 6 ali 8 tednov izpostavili delovanju testnih gliv modrivk Aureobasidium pullulans in Sclerophoma pithyophila. Z uporabo nedestruktivnih metod smo vzorcem pred in po izpostavitvi določili maso, modul elastičnosti, kemijske lastnosti (FTIR), barvo površine ter delež ogljika in dušika. Rezultati testa so pokazali, da sprememba mase in kemijske sestave lesa nista bistveni, medtem ko pa se modul elastičnosti rahlo poveča. Po pričakovanju smo določili tudi močno spremembo barve vzorcev, saj so le-ti zelo potemneli. Nazadnje smo z elementno analizo CNS ugotovili padec dušika v okuženih vzorcih. Na osnovi opisanih rezultatov sklepamo, da bi lahko pomodrel les v večjem obsegu uporabljali za konstrukcijski les oziroma za nosilne elemente.

• Language: Slovenian
• Keywords: glive modrivke, rdeči bor, nedestruktivne metode, mehanske lastnosti, melamin, razkroj
• Work type: Undergraduate thesis
• Typology: 2.11 - Undergraduate Thesis
• Organization: BF - Biotechnical Faculty
• Place of publishing: Ljubljana
• Publisher: [V. Vek]
• Year: 2007
• Number of pages: XI, 58 f.
• PID: 20.500.12556/RUL-239
• UDC: 630*844.1
• COBISS.SI-ID: 1563785
• Publication date in RUL: 11.07.2014

Secondary language

• Language: English
• Title: Changes of mechanical properties of wood as a consequence of blue stain fungi activity : univerzitetni študij

Abstract

Blue stain fungi change visual appearance of wood and supposedly do not influence mechanical properties of attacked wood. To prove or reject this hypothesis, specimens of pine wood (0.5 x 1.0 x 20.0 cm) were exposed to 2 blue stain fungi: Aureobasidium pullulans and Sclerophoma pithyophila for 2, 4, 6 or 8 weeks. Using non-destructive techniques, the following parameters were determined: mass, chemical properties (FTIR), colour of specimens, so as carbon and nitrogen content. Results showed that there are almost no chemical and mass changes: however slightly increased modulus of elasticity was determined. As expected, the colour of the specimens changed to dark tones. Furthermore, CNS analysis showed decrease of nitrogen content in colonized specimens. On the basis of these results, it can be concluded that such wood could be more extensively used for construction purposes.

• Keywords: blue stain fungi, Scotch pine, non-destructive methods, mechanical properties, melamin, decay