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Öğe Bonding Strength of Some Adhesives in Heat-Treated Hornbeam (Carpinus betulus L.) Wood Used for Interior and Exterior Decoration(North Carolina State Univ Dept Wood & Paper Sci, 2016) Uzun, Oguzhan; Percin, Osman; Altinok, Mustafa; Kureli, IhsanHeat-treated wood has an ever-expanding market for exterior and interior applications. The objective of this study was to determine the effect of a heat treatment on the bonding strength of hornbeam (Carpinus betulus L.) wood that was bonded with melamine formaldehyde (MF), polyurethane (PUR), and polyvinyl acetate (PVAc-D4) adhesives. Hornbeam lamellas were heat treated at 150 degrees C, 175 degrees C, 200 degrees C, and 225 degrees C for 3 h and then bonded. The bonding strength of the specimens was determined. In addition, the density, weight loss, and pH value of the heat-treated wood were investigated. The results showed that the bonding strengths of the heat-treated wood specimens decreased with the temperature of the heat treatment. The bonding strength of the PUR adhesive was higher than the MF and the PVAc-D4.Öğe Bonding Strength of Some Adhesives in Heat-Treated Hornbeam (Carpinus betulus L.) Wood Used for Interior and Exterior Decoration(North Carolina State Univ Dept Wood & Paper Sci, 2016) Uzun, Oguzhan; Percin, Osman; Altinok, Mustafa; Kureli, IhsanHeat-treated wood has an ever-expanding market for exterior and interior applications. The objective of this study was to determine the effect of a heat treatment on the bonding strength of hornbeam (Carpinus betulus L.) wood that was bonded with melamine formaldehyde (MF), polyurethane (PUR), and polyvinyl acetate (PVAc-D4) adhesives. Hornbeam lamellas were heat treated at 150 degrees C, 175 degrees C, 200 degrees C, and 225 degrees C for 3 h and then bonded. The bonding strength of the specimens was determined. In addition, the density, weight loss, and pH value of the heat-treated wood were investigated. The results showed that the bonding strengths of the heat-treated wood specimens decreased with the temperature of the heat treatment. The bonding strength of the PUR adhesive was higher than the MF and the PVAc-D4.Öğe Determination of Screw Withdrawal Resistance of Some Heat-Treated Wood Species(Zagreb Univ, Fac Forestry, 2017) Percin, Osman; Yasar, Sekip Sadiye; Altunok, Mustafa; Uzun, OguzhanIn this study, the screw withdrawal resistance of heat-treated hornbeam (Carpinus betulus L.), black pine (Pinus nigra Arnold) and Uludag fir (Abies bornmuellerinana Mattf.) was determined according to the ASTM D 1761 standard. For this purpose, wood materials were heat treated at 150, 170, 190 and 210 degrees C for 3 h. After the heat treatment, the screw withdrawal resistance of the wood was determined in radial, tangential and transverse directions. As a result, the screw withdrawal resistance values decreased with increasing heat treatment temperature and the lowest resistance was obtained in the wood heat-treated at 210 degrees C. In terms of wood species, the highest screw withdrawal resistance was found in hornbeam (Carpinus betulus L.), while the lowest value was observed in black pine (Pinus nigra Arnold). Additionally, in terms of the cross-sectional direction, the highest screw withdrawal resistance was determined in the tangential direction, while the lowest resistance value was observed in the transverse direction.Öğe Morphological, anatomical, palynological, karyological and autecological characters of Centaurea amaena Boiss. & Balansa [Sect. Phalolepis (Centaurea/Asteraceae)](Springer Wien, 2013) Atasagun, Bayram; Aksoy, Ahmet; Martin, Esra; Uzun, OguzhanCentaurea amaena Boiss. & Balansa included in the Phalolepis section of the Compositae (Asteraceae) family is an endemic species that is under critical risk of extinction. The morphological, anatomical, palynological, karyological and autecological features have been studied in this study. In accordance with the new observations, additional information was added to the previous description of the species, and the description was edited. Moreover, threat category of C. amaena has been updated according to International Union for Conservation of Nature criterions as CR B2ab(i,iii) (previously EN). Pollen grains are symmetric and isopolar, tricolporate. The somatic chromosome number is determined as 2n = 18 in C. amaena. The karyotype formula of this species consists of three median chromosome pairs and six submedian chromosome pairs. The physical and chemical properties of the soil in which the plant grows are, sandy-loam, weak acid, high organic matter.Öğe Physical and Mechanical Properties of Laminated Wood Made from Heat-Treated Scotch Pine Reinforced with Carbon Fiber(North Carolina State Univ Dept Wood & Paper Sci, 2023) Percin, Osman; Uzun, OguzhanLaminated veneer lumber (LVL) and reinforced laminated veneer lumber (RLVL) with carbon fiber were produced from heat-treated Scotch pine (Pinus sylvestris L.) wood using phenol formaldehyde (PF), polyvinyl acetate (PVAc), and polyurethane (PU) resins. Wood veneers were subjected to heat treatments at 150 degrees C, 170 degrees C, or 190 degrees C for 2 h before lamination. The effects of the reinforcement, heat treatment temperatures, and resins on the properties of the LVL and RLVL were analyzed. Density, equilibrium moisture content (EMC), modulus of rupture (MOR), and modulus of elasticity (MOE) were evaluated. The results showed that MOR and MOE values of solid wood and LVL specimens decreased with increasing treatment temperature. However, reinforcement with carbon fiber increased both MOR and MOE. In addition, the density values of the all RLVL specimens improved, and the EMC altered significantly for all test specimens. Compared to solid samples, the highest MOR values increased by approximately 21% in PF-RLVL samples. Similarly, the highest MOE values increased by 31% in PF-RLVL samples. In conclusion, carbon fiber, one of the most used fabric types in composites, could be utilized in the manufacture of reinforced LVL with heat-treated veneers.Öğe Physical and Mechanical Properties of Laminated Wood Made from Heat-Treated Scotch Pine Reinforced with Carbon Fiber(North Carolina State Univ Dept Wood & Paper Sci, 2023) Percin, Osman; Uzun, OguzhanLaminated veneer lumber (LVL) and reinforced laminated veneer lumber (RLVL) with carbon fiber were produced from heat-treated Scotch pine (Pinus sylvestris L.) wood using phenol formaldehyde (PF), polyvinyl acetate (PVAc), and polyurethane (PU) resins. Wood veneers were subjected to heat treatments at 150 degrees C, 170 degrees C, or 190 degrees C for 2 h before lamination. The effects of the reinforcement, heat treatment temperatures, and resins on the properties of the LVL and RLVL were analyzed. Density, equilibrium moisture content (EMC), modulus of rupture (MOR), and modulus of elasticity (MOE) were evaluated. The results showed that MOR and MOE values of solid wood and LVL specimens decreased with increasing treatment temperature. However, reinforcement with carbon fiber increased both MOR and MOE. In addition, the density values of the all RLVL specimens improved, and the EMC altered significantly for all test specimens. Compared to solid samples, the highest MOR values increased by approximately 21% in PF-RLVL samples. Similarly, the highest MOE values increased by 31% in PF-RLVL samples. In conclusion, carbon fiber, one of the most used fabric types in composites, could be utilized in the manufacture of reinforced LVL with heat-treated veneers.Öğe Properties of Heat-Treated Beech Laminated Veneer Lumber Reinforced with Carbon Fiber Fabric(North Carolina State Univ Dept Wood & Paper Sci, 2023) Percin, Osman; Uzun, OguzhanCarbon fiber fabric reinforced laminated veneer lumber (RLVL) pieces were prepared by using heat-treated beech (Fagus orientalis Lipsky) veneers with polyurethane (PU) adhesive as the binder. Carbon fiber fabric was tested in three different locations with solid material and non-reinforced samples (on the bottom adhesive line, upper adhesive line, and upper and bottom adhesive lines-symmetrical). Prior to the manufacture of LVL and RLVL, heat treatment was conducted in a laboratory oven at three temperatures. These temperatures were 150, 170, and 190 degrees C. Tests were performed on LVL and RLVL to determine their air-dried density, modulus of rupture (MOR), and modulus of elasticity in bending (MOE). Experimental test results showed that reinforcement with carbon fiber increased the air-dried density, MOR, and MOE. In addition, carbon fiber fabric placed symmetrically close to bottom and upper surfaces gave the highest MOR and MOE values. However, locating the carbon fiber fabric closer to the bottom surface tended to give higher mechanical properties for the reinforced LVL.Öğe Properties of Heat-Treated Beech Laminated Veneer Lumber Reinforced with Carbon Fiber Fabric(North Carolina State Univ Dept Wood & Paper Sci, 2023) Percin, Osman; Uzun, OguzhanCarbon fiber fabric reinforced laminated veneer lumber (RLVL) pieces were prepared by using heat-treated beech (Fagus orientalis Lipsky) veneers with polyurethane (PU) adhesive as the binder. Carbon fiber fabric was tested in three different locations with solid material and non-reinforced samples (on the bottom adhesive line, upper adhesive line, and upper and bottom adhesive lines-symmetrical). Prior to the manufacture of LVL and RLVL, heat treatment was conducted in a laboratory oven at three temperatures. These temperatures were 150, 170, and 190 degrees C. Tests were performed on LVL and RLVL to determine their air-dried density, modulus of rupture (MOR), and modulus of elasticity in bending (MOE). Experimental test results showed that reinforcement with carbon fiber increased the air-dried density, MOR, and MOE. In addition, carbon fiber fabric placed symmetrically close to bottom and upper surfaces gave the highest MOR and MOE values. However, locating the carbon fiber fabric closer to the bottom surface tended to give higher mechanical properties for the reinforced LVL.Öğe Screw Withdrawal Strength of Heat-Treated and Laminated Veneer Lumber Reinforced with Carbon and Glass Fibers(North Carolina State Univ Dept Wood & Paper Sci, 2022) Percin, Osman; Uzun, OguzhanThe strength of a structural system often depends on the interconnections between the components of the structure. Screws are one of the most widely used fasteners in construction. In this study, the screw withdrawal strength of heat-treated scotch pine (Pinus sylvestris L.) samples reinforced with glass and carbon fibers via Desmodur-vinyl trie ketonol acetate adhesive was investigated. Before manufacturing the laminated veneer lumber, the wood samples were subjected to heat treatment at a temperature of 150 ??C, 170 ??C, 190 ??C, and 210 ??C for 2 h. Test results showed that the reinforcement fiber type and heat treatment temperatures had a considerable effect on the screw withdrawal strength. Heat treatment reduced the screw withdrawal strength, while the samples reinforced with both fibers had higher screw withdrawal strengths than those without reinforcement. Reinforcement with glass and carbon fibers increased the screw withdrawal strength up to 38% and 49% in the tangential, 13% and 20% in the radial, and 17% and 25% in the axial direction, respectively, compared to solid wood. In addition, the laminated veneer lumber samples reinforced with carbon fiber had a considerable increase in the screw withdrawal strength compared with the solid wood and glass fiber reinforced samples.Öğe Screw Withdrawal Strength of Heat-Treated and Laminated Veneer Lumber Reinforced with Carbon and Glass Fibers(North Carolina State Univ Dept Wood & Paper Sci, 2022) Percin, Osman; Uzun, OguzhanThe strength of a structural system often depends on the interconnections between the components of the structure. Screws are one of the most widely used fasteners in construction. In this study, the screw withdrawal strength of heat-treated scotch pine (Pinus sylvestris L.) samples reinforced with glass and carbon fibers via Desmodur-vinyl trie ketonol acetate adhesive was investigated. Before manufacturing the laminated veneer lumber, the wood samples were subjected to heat treatment at a temperature of 150 ??C, 170 ??C, 190 ??C, and 210 ??C for 2 h. Test results showed that the reinforcement fiber type and heat treatment temperatures had a considerable effect on the screw withdrawal strength. Heat treatment reduced the screw withdrawal strength, while the samples reinforced with both fibers had higher screw withdrawal strengths than those without reinforcement. Reinforcement with glass and carbon fibers increased the screw withdrawal strength up to 38% and 49% in the tangential, 13% and 20% in the radial, and 17% and 25% in the axial direction, respectively, compared to solid wood. In addition, the laminated veneer lumber samples reinforced with carbon fiber had a considerable increase in the screw withdrawal strength compared with the solid wood and glass fiber reinforced samples.
