Vpliv zgradbe branike na gostoto in dimenzijsko stabilnost lesa rdečega bora

diplomsko delo

Žan Škrinjar (Avtor), Aleš Straže (Recenzent), Maks Merela (Mentor)

Povzetek

Bori v gozdovih Slovenije predstavljajo približno 6 % lesne zaloge. Predhodne raziskave so pokazale, da med rastišči obstajajo razlike, tako v pojavnosti obsega in intenzivnosti jedrovine, kot tudi v širini branik. V literaturi ni mogoče najti natančnih podatkov o zvezi med deleži ranega in kasnega lesa ter dimenzijsko stabilnostjo. Dimenzijska stabilnost je pomembna z vidika uporabe lesa in ni odvisna le od ojedritvenih procesov ter od deleža ekstraktivnih snovi v lesu. S pomočjo finega brušenja in visoko-ločljivostnega skeniranja smo izdelali kvalitetne fotografije površin lesa na prečnih prerezih rdečega bora. S programsko opremo NIS-Elements ter ImageJ smo dobili razmerje med ranim in kasnim lesom ter izmerili širine branik. Pridobljene parametre posameznega vzorca smo nato uporabili za preučevanje korelacij med širinami branik ter deleži ranega in kasnega lesa, gostoto in dimenzijsko stabilnostjo. Rezultati so pokazali, da so drevesa iz ugodnejših rastišč imela les s širšimi branikami, ki je imel večji delež ranega lesa. Les z večjim deležem ranega lesa je imel manjše skrčke in nižjo gostoto. Vzorci lesa z ožjimi branikami so imeli večji delež kasnega lesa, večji volumski srček in večjo prečno krčitveno anizotropijo. Istočasno pa ima les z ožjimi branikami višjo gostoto in z njo povezane boljše mehanske lastnosti.

Ključne besede

anatomija lesa;rdeči bor;gostota lesa;dimenzijska stabilnost;

Podatki

Jezik:	Slovenski jezik
Leto izida:	2018
Tipologija:	2.11 - Diplomsko delo
Organizacija:	UL BF - Biotehniška fakulteta
Založnik:	[Ž. Škrinjar]
UDK:	630*811.4
COBISS:	2944137
Št. ogledov:	902
Št. prenosov:	201
Ocena:	0 (0 glasov)
Metapodatki:

Ostali podatki

Sekundarni jezik:	Angleški jezik
Sekundarni naslov:	Growth ring structure impact on density and dimensional stability of Scotch Pine
Sekundarni povzetek:	Pines in the forests of Slovenia represent approximately 6% of the forest stock. Previous studies have shown that there are differences between habitats, in both the incidence of scale and intensity of heartwood, as well as the width of the growth rings. No accurate data is possible to find in the literature on the relationship between the shares of early and late wood and dimensional stability. Dimensional stability is important in terms of the use of wood and does not depend only on the enzymatic processes and on the portion of extractive substances in the wood. With fine grinding and high-resolution scanning we made high quality photos of the surfaces of wood on the cross-sections of Scotch pine. With computer software NIS-Elements and Image-J we calculated the ratios between early wood and late wood and we measured the width of the growth rings. Then we used gathered data of each sample to study correlations between widths of the growth rings and percentage of early and late wood, between density and dimensional stability. Results showed that the trees from better growth sites had wood with wider growth rings and bigger percentage of early wood. Wood with bigger percentage of early wood had smaller shrinkage and lower density. Wood samples with narrower growth rings had bigger percentage of late wood, bigger volume shrinkage and bigger transverse anisotropy. At the same time the wood with narrower growth rings has higher density and better mechanic properties correlated to higher density.
Sekundarne ključne besede:	anatomy of wood;Scotch pine;density of wood;dimensional stability;
Vrsta dela (COBISS):	Diplomsko delo/naloga
Študijski program:	0
Komentar na gradivo:	Univ. v Ljubljani, Biotehniška fak., Oddelek za lesarstvo
Strani:	IX, 51 f., [3] f. pril.
ID:	10959911