No abstract

This study evaluates the effect of 1% to 5% NaOH treatments of cotton stalk particles on the chemical composition and physical and mechanical properties of particleboards produced with this material. Gas chromatography and Fourier transform infrared (FTIR) spectroscopy indicated that the extractive, hemicellulose, and lignin content of the particles decreased during the alkali treatments, whereas the cellulose content increased. Thermogravimetric analysis (TGA) indicated that the untreated particles exhibited higher thermal stability than the particles treated with NaOH. The decrease in thermal stability of alkali-treated particles seems to be due to degradation of chemical components. Alkali treatments raised water absorption (WA) and thickness swelling (TS) of the produced particleboards. Except for 1% NaOH, the treatments reduced the modulus of elasticity (MOE), modulus of rupture (MOR), and internal bond (IB) strength in relation to the board made with untreated particles. The 1% NaOH treatment of cotton stalks was more effective and beneficial, leading to particleboards with satisfying MOE, MOR, and IB values that met the requirements for general-purpose particleboards used in dry conditions, as indicated by the TS-EN 312 (2012) standard.

The genus Taxus L. is classified in the family of Taxaceae and represented by eight species 1,2 . Taxus (yew) species range from North America into Central America and from Eurasia to Southeast Asia 3 . Only one species of Taxus is growing in Turkey, which is Taxus baccata L., a toxic plant and called European yew 4 .Volatile compounds were extracted from T. baccata L. leaves collected from northern Turkey (Black sea region) have been studied by Erdemoglu et al. 5 . However, the geographical place of growth of the plant influences chemical composition of the volatile oil 6 . Therefore, the essential oils of T. baccata L. leaves collected from western (Aegean region) and southern (Mediterranean region) Turkey were analyzed by gas chromatographic method using flame ionization and mass selective detections in this study. EXPERIMENTALThe leaves of T. baccata L. were collected from Bozdag-Acipayam/Denizli in Aegean region of Turkey at an altitude of 1450 m and Egirdir/Isparta in Mediterranean region of Turkey about 1100 m in july 2012. The fresh materials were carried in frozen bags to laboratory and then stored at -20 ºC. Voucher specimen is deposited at Herbarium of the Forest Botany Department of Suleyman Demirel University as F4859 and F4865.

Utjecaj tehnike ekstrakcije na sastav hlapljivih sastojaka oleoresina iz drva Pinus brutia Ten.

In this study the utilization of kermes oak (Quercus coccifera L.) wood, which could be used as an industrial raw material for the production of fiberboard, was investigated. In the experimental design, boards were produced from mixtures of kermes oak and brutian pine (Pinus brutia Ten.