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Öğe The bending moment capacities of mitre frame cornerjoints with dovetail fittings(2009) Kiliç, M.; Burdurlu, E.; Altun, S.; Berker, U.Ö.In this study, the bending moment capacities under the diagonal compression and tensile loadings of the mitre frame corner joints with dovetail fittings were investigated. Solid poplar wood (Populus nigra) was used in the production of framework pieces. Recently, mitre frame corner joints with dovetail fitting are preferred in practice. This has been influential in the making of this study. A total of 80 each mitre frame corner joint specimens with dovetail fitting were prepared for this purpose. Of these, 20 were prepared with polyvinyl acetate (PVAC) adhesive, 20 were prepared with polyurethane (PU) adhesive, 20 were prepared with cyanoacrylate (CA) adhesive and 20 were prepared without adhesive (WA). Solid poplar wood (Populus nigra) was used as a frame material. The specimens were subjected to diagonal tensile and compression processes in the universal test machine in accordance with ASTM-D 143-94. The data obtained at the end of the tests were analyzed statistically and the results were evaluated. According to this, the highest bending moment capacity under the diagonal compression loading (MC-L) (55.71 N · m) and bending moment capacity under the diagonal tensile loading (MC-T) (160.55 N · m) was obtained in the specimens bonded with PVAC adhesive. Whereas, the lowest MC-L (18.45 N · m) and MC-T (14.06 N · m) was obtained in the specimens without adhesive (WA). The difference between the MC-T and the MC-Cof the specimens bonded with the CA and PU adhesives was insignificant. Accordingly, it is definitely necessary to use adhesives in the bonding of dovetail fittings for obtaining a higher MC-T and MC-C. The best result among the available adhesives was obtained with the PVAC adhesive.Öğe Effect of adhesive type on the bending moment capacity of miter frame corner joints(2010) Altun, S.; Burdurlu, E.; Kiliç, M.The bending moment capacity was studied under the diagonal tensile and compression loadings of miter corner joints with dovetail fitting in frames made with medium density fiberboard (MDF). The influence of the type of adhesive in the joints with dovetail fitting on bending moment capacity under diagonal tensile and compression loading were considered, and the joints without adhesive were compared. A total of 80 each miter frame corner joint specimens with dovetail fitting were made. Polyvinyl acetate (PVAc), polyurethane (PU), and cyanoacrylate (CA) adhesives were used, and 20 specimens were prepared without adhesive (WA) with dovetail fitting. MDF was used as a frame material, as in normal practice. The specimens were subjected to diagonal tensile and compression loadings in accordance with ASTM-D 143-94. The data were analyzed statistically. The highest bending moment capacity under diagonal tensile loading (46.09 Nm) was obtained in the specimens bonded with CA adhesive and the highest bending moment capacity under diagonal compression loading (72.04 Nm) was obtained in the specimens glued with PVAc adhesive. Other than this, since there is no difference between these and the unbonded joints, the PU adhesive was not effective in increasing the bending moment capacity under diagonal tensile loading, and the PU and CA adhesives were not effective in increasing the bending moment capacity under diagonal compression loadings.Öğe Effects of silica gel on leaching resistance and thermal properties of impregnated wood(2010) Altun, S.; Ozcifci, A.; Senel, A.; Baysal, E.; Toker, H.The aim of this study was to increase the resistance of fire retardant chemicals for leaching in order to improve the fire resistance of wood. For this purpose, Scots pine (Pinus sylvestris L.) and Chestnut (Castanea sativa Mill.) wood impregnated with 3 % aqueous solutions of boric acid, zinc chloride and aluminum chloride at 60 °C by using vacuum- press impregnating method according to ASTM D1413-07 standard. In order to increase leaching resistance of the chemicals, wood samples post-treated with sodium silicate and then sodium bicarbonate to form insoluble silica gel in wood. After leaching test, it was determined that silica gel treatment decreased the amount of leachant in all three impregnation solutions. Effect of silica gel on the thermal behavior of treated samples was determined via termogravimetric analysis (TGA). According to the results of TGA silica gel treatment improved the fire resistance property of wood especially in boric acid treated wood.Öğe Glossiness, color stability, and surface roughness of wood treated with some bleaching chemicals(2009) Ozcifci, A.; Yapici, F.; Altun, S.; Toker, H.; Baysal, E.; Senel, A.; Simsek, H.The aim of this study was to determine the effects of different bleaching chemicals and their treatment time on glossiness, color stability, and surface roughness of wood. Spruce (Picea orientalis L.) and oak (Quercus sessiliflora Salisb.) wood specimens were bleached with aqueous solutions of 25% hydrogen peroxide (H2O2), 25% ammonia (NH3), and their mixture (1:1;volume:volume) for 10, 20, and 30 minutes immersing. Glossiness of wood specimens parallel and perpendicular to grain values were measured with Glossmeter at 60-degree incident angle. Color measurements and surface roughness were wade according to ISO 7724 - 2, and ISO 4287 standards, respectively. Results showed that the highest glossiness decrease (0.99) was observed in oak wood treated with ammonia solution perpendicular to grain for 20 min. immersing. The highest total color chance (18.88) was observed in oak wood treated with ammonia solution for 30 minutes immersing. All bleaching solutions increased the surface roughness of wood specimens.Öğe Intertrochanteric fractures in patients with lower limb amputation(E-Century Publishing Corporation, 2016) Ercin, E.; Baca, E.; Altun, S.; Bilgili, M.G.; Kural, C.; Basaran, S.H.Fracture of the residual limb in an amputee is uncommon. Intertrochanteric fractures of patients who had lower limb amputation have been studied only in several case reports; however clinical studies are lacking. We performed a retrospective clinical study to assess if these patients could return to their pre-fracture activity level after dynamic hip screw (DHS) fixation of their intertrochanteric fractures. Our hypothesis is that DHS fixation of intertrochanteric fractures in these patients would give good results with fracture union and could help to return to the previous activity level. We retrospectively reviewed data of the 12 patients (between the period of January 2006 and March 2013) who underwent DHS fixation of an intertrochanteric fracture on the ipsilateral side of a major lower limb amputation (above knee or below knee amputations). Age, gender, amputation level, amputation reason, time since amputation, mechanism of injury at the time of fracture, operation time, length of hospital stay, time to bone union and activity level were documented. Patient’s activity level after one year of operation and union time were evaluated as primary outcomes. During the study period, 12 patients were included with seven (58.3%) male and five (41.7%) female. Mean age at the time of fracture was 57.6 years (range 48 to 72 years). All of the fractures were classified according to AO/OTA as 31A1. There were four patients (33.3%) with above knee and eight patients (66.7%) with below knee amputation. Mean time to bony union in twelve patients was 18 weeks (range 8 to 24 weeks). Ninety-two percent of these patients returned to pre-fracture activity level. There were no implant failure or nonunion at the minimum two-year follow-up period. DHS fixation of intertrochanteric hip fractures in patients with ipsilateral amputated limb provides good results of returning pre-fracture activity levels. Bone union time found to be similar in these patients when compared with patients with a normal limb. © 2016, E-Century Publishing Corporation. All rights reserved.Öğe An investigation on compression parallel to grain values of wood impregnated with some boron compounds(2008) Toker, H.; Baysal, E.; Ozcifci, A.; Altinok, M.; Sonmez, A.; Yapici, F.; Altun, S.This study was carried out to determine compression strength parallel to grain of wood impregnated with some boron compounds. Sodium perborate (SP) boric acid, (BA), and borax (BX) were used as boron compounds. Wood specimens were prepared from Calabrian pine (Pinus brutia Ten.) and beech (Fagus orientalis L.) wood. Before compression test parallel to grain, wood specimens were impregnated with aqueous solutions (1, 2, 3, 4, 5, and 6 %) of boron compounds according to ASTM D 1413(1976). Results showed that compression strength parallel to grain values ofwood specimens treated with boron compounds were lower compared to untreated control specimens. Borate treatments reduced compression strength parallel to grain of wood in significant level compared to untreated control. The compression strength parallel to grain values ofwood specimens were the highest for untreated control specimen followed by BA, BX, and SP treated wood specimens, respectively. In general, our results showed that the higher concentration levels of boron compounds, the lower compression strength parallel to grain values of wood resulted.Öğe Shear strength of heat-treated tali (Erythrophleum ivorense) and iroko (Chlorophora excelsa) woods, bonded with various adhesives(2009) Kol, H.S.; Özbay, G.; Altun, S.The aim of this study was to evaluate the effect of heat treatment on the shear strength of tali (Erythrophleum ivorense) and iroko (Chlorophora excelsa) woods, bonded with some structural adhesives. Shear strength of untreated and heat-treated woods bonded with phenol-formaldehyde (PF), melamine-urea-formaldehyde (MUF), melamine-formaldehyde (MF), and polyurethane (PUR) adhesives was studied. An industrial heat treatment method (ThermoWood) was used. The timbers were thermally modified for 2 hours at 180 °C. Laminated samples having two sample sets were prepared from untreated and heat-treated wood for the shear strength test. The results of the tests showed that the heat treatment affected shear strength of laminated wood negatively. Although there was a considerable difference in adhesive bond shear strength between untreated and treated wood, both wood species bonded with the adhesives fulfilled the required value for shear strength of the adhesive bonds. PF, MUF, MF, and PUR adhesives performed in a rather similar way for both wood species.Öğe Some combustion parameters of wood impregnated with borates(2009) Toker, H.; Baysal, E.; Ozcifci, A.; Simsek, H.; Altun, S.; Yapici, F.; Goktas, O.This study was conducted to determine some of the combustion parameters of Calabrian pine and Oriental beech treated with borates. Average mass loss and temperature values of Calabrian pine and Oriental beech wood were determined according to ASTM E-69. Boric acid, borax, and sodium perborate were used as borates. Before the combustion test, wood specimens were impregnated with aqueous solutions (1%, 2%, 3%, 4%, 5%, and 6%) of borates according to ASTM D1413-76. These results showed that mass loss and temperature values of both wood specimens treated with borates were lower compared to the untreated control specimens. Higher concentration levels of borates resulted in lower mass loss and temperature values of the wood. ©Forest Products Society 2009.
