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Öğe Antifungal Effects of Staining Process on Wood: Hardness, Gloss, and Color Change(North Carolina State Univ Dept Wood & Paper Sci, 2023) Budakçı, Mehmet; Korkmaz, Mustafa; Karal, İpekThis study determined the effects of wood staining on wood-destroying fungi. To achieve this goal, different types of wood samples were used, including Scotch pine (Pinus sylvestris L.), Eastern beech (Fagus orientalis Lipsky), sessile oak (Quercus petraea Liebl.), and mahogany (Entandrophragma cylindricum). Aniline (C6H2NH2), chemical (tannin (C1uH1oOs) + potassium dichromate (K2Cr2O7)), and Van Dyke brown stains (Fe2O3MnO2 + K2Cr2O7 + H2O) were applied to the samples, because a walnut color (brown) is preferred by customers. The stained samples were exposed to Fomitopsis palustris and Coriolus versicolor, and mycelium growing on wood was observed for 3 months. Hardness, gloss, and total color change tests were applied to the samples to determine the antifungal effects. The results showed that staining increased the total color change values of the wood, while decreasing in the gloss and hardness values. The chemical stain showed antifungal effects against both fungi.Öğe An application of fuzzy soft sets to a real-life problem: Classification of wood materials to prevent fire-related injuries and deaths(Elsevier, 2023) Korkmaz, Esra; Özcan, Cemal; Korkmaz, MustafaA variety of methods are used to determine the health and life-threatening consequences of wood combustion. However, these methods suffer from some limitations. They analyze the data obtained during combustion individually rather than evaluating them together. Furthermore, they do not take into account the fact that some of the parameters that influence the process can be positive, while others can be negative, or that they may not be of equal importance. In this study, we present a fuzzy soft set-based algorithm to handle such issues. The proposed algorithm can also deal with problems arising when the membership values of the objects are close together. It also contributes a novel approach to the literature regarding the selection of wood materials that are suitable for use in fireprone areas. In order to demonstrate the applicability of our approach we performed an experiment and analyzed wood materials, which are frequently used in wooden structures, according to parameters that may affect human life and health. We also highlight how the present work contributes to the state-of-the-art by interpreting our results using a method that already exists in the literature. (c) 2022 Elsevier B.V. All rights reserved.Öğe Borik Asit İlave Edilen Bazı Tutkalların Kayın Odununun Yanma Özelliklerine Etkisinin Belirlenmesi(2014) Yuca, Bilal; Kurt, Şeref; Korkmaz, Mustafa; Aysal, SemaAğaç malzeme, doğal olması nedeniyle daima insanoğlunun yakınlık duyduğu ve pek çok alanda çok farklı amaçlarla kullandığı bir malzemedir. Bu çalışmada, kayın odunu örneklerinden elde edilen deney örnekleri ASTM-E-69, TS 3891 standartlarında verilen esaslara göre hazırlanmış ve daha sonra borik asit katkılı fenol formaldehit, üre formaldehit ve PVAc tutkalları ile lamine edilmiştir. Daha sonra elde edilen lamine ağaç malzemelerin yanma direnci özellikleri araştırılmıştır. Yanma deneyi için hava kurusu rutubetteki (% 12) taslaklar 4,5x19x1016 mm boyutlarında hazırlanmıştır. Daha sonra yapıştırma işlemleri uygulanmıştır. Bu amaçla, %5lik çözelti halinde hazırlanan borik asitten fenol formaldehit, üre formaldehit ve PVAc tutkallarına % 5 oranında ilave edilerek kullanılmıştır. ASTM-E 69 esaslarına göre yanma değerleri belirlenmiştir. Yanma olayında borik asidin yanmayı geciktirici bir etkisi olduğu tespit edilmiştir. Yapışma direnci deney örnekleri, 5x18x150 mm boyutlarında hazırlanmıştır. Daha sonra yapıştırma işlemleri uygulanmıştır.Öğe Determination of relationship between thermal and mechanical properties of wood material(Korean Society of Wood Science Technology, 2019) Özcan, Cemal; Korkmaz, MustafaNon-destructive test techniques are becoming increasingly important for assessment and maintenance. These techniques are very useful for assessment of materials such as wood, whose performance can vary considerably depending on the conditions of use. It is possible to estimate some mechanical properties of a material by determining the movement of energy through the material with the help of these techniques. In this study, it was investigated whether the wood material could be tested nondestructively by the heat energy produced by a source. The correlations between the thermal conductivity and mechanical properties of Scots pine (Pinus sylvestris L.) and sessile oak (Quercus petraea L.) woods were investigated. The thermal conductivity (TC), density, modulus of rupture (MOR), compression strength (CS), and modulus of elasticity (MOE) values of samples were measured according to the related standards and these values were correlated with each other. The linear and multiple regression tests were employed to determine the correlation between thermal conductivity and mechanical properties. The results showed that there is a very strong correlation between thermal conductivity and both density and MOR values. However, the correlations between TC and both MOE and CS were moderate. The results of this study suggest that the thermal conductivity value can be used to estimate the density and some mechanical properties of wood. © 2019, Korean Society of Wood Science Technology. All rights reserved.Öğe The effect of some chemicals on the color properties of Beech (Fagus Orientalis L.) wood(Kastamonu Univ, Orman Fak, 2017) Yıldız, Abdülkadir; Yapıcı, Fatih; Korkmaz, Mustafa; Pelit, HüseyinAim of study: Wood material has a unique color in the natural condition. The wood colorization process is necessary to provide a tonality in the wood materials used in interior design and decoration and to obtain different colors. One of the most important steps of the coloring or bleaching process is selecting appropriate chemical for wood type. The aim of this study was to determine the effect of hydrogen peroxide, ammonia, sodium silicate and acetic acid applied periodically three times on the color changes of radial and tangent sections of beech (Fagus Orientalis L.) samples. Area of study: This study was conducted at Karabuk University and Duzce University, in Turkey. Material and Methods: The color values of the samples were measured according to the CIEL*a*b* color system. Main results: As a result, the effect of cutting direction, chemical type, and application repeat on changes in the color values of beech samples was found significant. Research highlights: The maximum color change in the beech samples was determined in the radial section as cutting direction, in the application of the sodium silicate as the chemical type and it was also obtained in the third repeat as the number of applications.Öğe The effect of some chemicals on the color properties of Beech (FagusOrientalis L.) wood(2017) Yıldız, Abdülkadir; Yapıcı, Fatih; Korkmaz, Mustafa; Pelit, HüseyinÇalışmanın amacı: Doğal haldeki ağaç malzemenin kendine özgü bir rengi vardır. İç mimari ve dekorasyonda kullanılan ağaç malzemelerde renk uyumunu sağlamak veya farklı görüntüler elde etmek için çoğu zaman renklendirme ve renk açma işlemlerine ihtiyaç vardır. Renklendirme veya renk açma işleminin en önemli basamaklarından birisi ağaç türüne uygun kimyasalın seçilmesidir. Bu araştırmanın amacı, kayın (Fagus Orientalis L.) odunundan radyal ve teğet kesitte hazırlanmış örneklere belirli aralıklarla üçer kez uygulanan hidrojen peroksit, amonyak, sodyum silikat ve asetik asit kimyasallarının örneklerde meydana getirdiği renk değişimini belirlemek içindir. Çalışma alanı: Bu çalışma Karabük Üniversitesi ve Düzce Üniversitesinde gerçekleştirilmiştir. Materyal ve Yöntem: Örneklerin renk değerleri CIEL*a*b* renk sistemine göre ölçülmüştür. Sonuçlar: Araştırma sonuçlarına göre; kayın örneklerin renk değerlerindeki değişimde kesiş yönü, kimyasal çeşidi ve uygulanma tekrarı önemli bulunmuştur. Araştırma vurguları: Örneklerdeki en fazla renk değişiminin; kesiş yönü olarak radyal kesitte, kimyasal çeşidi olarak sodyum silikat uygulamasında ve uygulama sayısında ise üçüncü tekrarda olduğu belirlenmiştirÖğe Effect of Water Based Varnishes Added Nano-Graphene on the Surface Properties of Beech (Fagus orientalis Lipsky) Wood(Gazi Univ, 2019) Pelit, Hüseyin; Korkmaz, MustafaIn this study, surface glossiness, roughness, hardness, color change, and varnish adhesion resistance properties of beech (Fagus orientalis Lipsky) wood samples coated with nano-graphene (NG) modified water based varnishes were investigated. 0.25%, 0.50% and 1% by weight of NG were added to the water-based varnish and the prepared solution was applied to the samples surfaces. According to the results of the research, the surface glossiness of the samples decreased and the roughness values increased slightly due to the increase of NG in the varnish. On the other hand, the increase in the amount of NG provided significant increases in varnish adhesion resistance up to 25%. The surface hardness value of beech samples increased up to 13% after varnishing. However in contrast to the predicted, effect of NG on hardness values was found to be insignificant. On the other hand, the values of L*, a* and b* decreased significantly with the increase of NG ratio. The samples were darkened and the green-blue color tendency of the samples increased. As a result, it may be recommended that NG addition can be prefer in the water based varnishes to provide high adhesion strength and in the surface darkening process.Öğe The Effects of Densification and Heat Post-Treatment on Hardness and Morphological Properties of Wood Materials(North Carolina State Univ Dept Wood & Paper Sci, 2016) Budakçı, Mehmet; Pelit, Hüseyin; Sönmez, Abdullah; Korkmaz, MustafaThis study investigated the effects of densification and heat post-treatment on the Janka hardness and microscopic structure of relatively low-density Uludag fir, linden, and black poplar woods. Wood samples were densified with compression ratios of 25% and 50% at 100 degrees C and 140 degrees C, respectively. Heat post-treatment was then applied to the samples at 185 degrees C and 212 degrees C for 2 h. The hardness in the radial and tangential directions was determined, and morphological changes in the cell structures were analyzed using scanning electron microscopy (SEM). The hardness values in the radial and tangential directions of the densified samples increased depending on the compression rate and treatment temperature. The hardness values in both directions were higher in the 50% compressed samples. For samples compressed at 140 degrees C, the hardness values were higher in the tangential direction, whereas the samples compressed at 100 degrees C were higher in the radial direction. After the heat post-treatment process, the hardness values of all samples decreased. As the treatment temperature increased, more adverse effects on the hardness was noted. According to the SEM analyses, the densification and heat post-treatment deteriorated the cell structure of the samples. The more cell deformation was observed in the samples densified at 100 degrees C with compression ratio 50% and high heat post-treatment temperature.Öğe Effects of Moisture and Direction of Grain on the Thermal Conductivity and Mechanical Properties of Black Alder and Scots Pine(Kastamonu Univ, 2022) Kurt, Şeref; Korkmaz, MustafaAim of study: Relationships between moisture content and thermal conductivity and mechanical properties of wood species were examined. Material and methods: Black Alder (Alnus glutinosa L.) and Scots Pine (Pinus sylvestris L.) specimens were used. Thermal conductivity, modulus of rupture, compression strength and impact bending strength values were determined and analyzed. All specimens were examined at 3 different moisture levels which are oven-dry, fiber saturation point (FSP) and completely wet. Main results: The lowest thermal conductivity value was found in the perpendicular to the grain direction of oven dried Black Alder samples as 0.119 W/mK. The highest thermal conductivity value was found in the parallel direction of Scots pine samples with FSP humidity content as 0.340 W/mK. In addition, the thermal conductivity value parallel to the grain is significantly higher than perpendicular one at all three moisture levels. Highlights: While there is a positive linear relationship between the moisture content of the wood and its dynamic bending resistance and thermal conductivity; It was found that there is a negative linear relationship between bending strength and compressive strength value.Öğe Effects of Thermo-Vibro-Mechanic (R) Densification on the Density and Swelling of Pre-Treated Uludag Fir and Black Poplar Wood(North Carolina State Univ Dept Wood & Paper Sci, 2021) Budakci, Mehmet; Senol, Suleyman; Korkmaz, MustafaThe radial and tangential swelling as well as the fully dried density of low-density wood materials densified via the Thermo-Vibro-Mechanic (R) method were evaluated in response to applying wood stain and preservative. The samples obtained from Uludag fir (Abies bornmuelleriana Mattf.) and black poplar (Populus nigra L.) in the radial and tangential direction were pre-treated with wood stain and preservative before undergoing Thermo-Vibro-Mechanic (R) densification. Thermo-Vibro-Mechanic (R) densification was performed at three different temperatures (100 degrees C +/- 3 degrees C, 120 degrees C +/- 3 degrees C, and 140 degrees C +/- 3 degrees C), three different vibration pressures (0.60 MPa, 1.00 MPa, and 1.40 MPa), and three different vibration times (20 s, 60 s, and 100 s). Afterwards, changes in the fully dried density and swelling amounts in the radial and tangential directions of the samples were determined. The fully dried density increased by 15.4% to 38% and the radial and tangential swelling amounts increased by 73.2% to 242.6%, when the densified samples were compared to the control samples. In general, the fully dried density and swelling values increased depending on the Thermo-Vibro-Mechanic (R) densification parameters; higher values were found as the compression ratio and total application time increased.Öğe Relationship Between the Thermal Conductivity and Mechanical Properties of Uludag Fir and Black Poplar(North Carolina State Univ Dept Wood & Paper Sci, 2018) Özcan, Cemal; Korkmaz, MustafaThe relationship between the thermal conductivity and some mechanical properties of Uludag fir and black poplar specimens were determined based on related standards. It was hypothesized that thermal conductivity can be used as a predictor for wood properties. The hot plate test method was used as a thermal conductivity testing method. The density, compression strength, modulus of rupture, and modulus of elasticity values were also measured. Pearson's correlation coefficient was determined and both linear and multiple regression analyses were performed to estimate the relationship between the parameters. The correlation between the thermal conductivity and density values was strong, which was consistent with past findings. Also, there was a strong correlation between the thermal conductivity, modulus of rupture, and modulus of elasticity, while the compression strength and thermal conductivity had a moderate correlation. The regression equations and test graphs were also determined and shown. Overall, it can be claimed that the thermal conductivity could be used for predicting the density and mechanical properties of wooden materials.Öğe Surface Roughness of Thermally Treated Wood Cut with Different Parameters in CNC Router Machine(North Carolina State Univ Dept Wood & Paper Sci, 2021) Pelit, Huseyin; Korkmaz, Mustafa; Budakci, MehmetThe effects of different machining parameters on surface roughness values of thermally treated pine, beech, and linden woods cut in a computer numerical control (CNC) router machine were examined. Wood specimens were thermally treated at 170, 190, and 210 degrees C for 2 h. Then, specimens were cut in the radial and tangential directions with three different spindle speeds (12000, 15000, and 18000 rpm) and three different feed rates (3000, 4000, and 6000 mm/min) using two different end mill tools (spiral and straight) on the CNC machine. The end mill type significantly affected the roughness values of the untreated and thermally treated specimens in both directions. Lower roughness values were found in the specimens (especially pine) machined with the straight end mill compared to those machined with the spiral end mill. Roughness generally decreased in the thermally treated specimens. However, thermal treatment temperature did not have a notable effect on roughness. As the spindle speed increased, the roughness values of all specimens decreased. In contrast, as the feed rate increased, the roughness values increased. Therefore, the end mill type, feed rate, and spindle speed were the most influential parameters on the roughness.Öğe Thermo-Vibro-Mechanic (R) (TVM) Wood Densification Method: Mechanical Properties(North Carolina State Univ Dept Wood & Paper Sci, 2022) Budakçı, Mehmet; Şenol, Süleyman; Korkmaz, MustafaA densification method is proposed and developed to improve the mechanical properties of Uludag. fir (Abies bornmuelleriana Mattf.) and black poplar (Populus nigra L.) woods. The method, called Thermo-VibroMechanic (R) densification, is derived from the hypothesis that the vibration added to the traditional thermo-mechanical densification process can cause the wood cell walls to interlock with each other at the micro-level via the friction effect. In addition, it aims to remove the cell cavities under lower pressure compared to other densification methods via the shaking effect. To test this hypothesis, the samples, obtained in both the radial and tangential directions, were pre-treated with wood stain and preservative before undergoing the densification process. Thermo-Vibro-Mechanic (R) densification was performed at varying temperatures (100, 120, and 140 degrees C), pressures (0.60, 1.00, and 1.40 MPa), and durations (20, 60, and 100 s). The changes in the values of the bending strength, modulus of elasticity, and compression strength parallel to the grain in the radial and tangential directions were determined accordingly. The results showed that the Thermo-Vibro-Mechanic (R) densification process increased the bending strength and modulus of elasticity values up to 50%, while the compression strength reached 67% higher than the untreated wood.Öğe The Use of Environmentally Friendly Abrasive Blasting Media for Paint Removal from Wood Surfaces(North Carolina State University, 2023) Kılınç, İzham; Budakçı, Mehmet; Korkmaz, MustafaThis study determined some physical changes that occur on wood surfaces aged in a marine environment resulting from the removal of coatings using environmentally friendly media blasting. Scots pine (Pinus sylvestris L.) wood coated with water-borne and synthetic paints was exposed to a marine environment for 100 days. The aged paint layers were removed using five different media (sodium bicarbonate, hazelnut shell granules, corncob granules, walnut shell granules, and apricot kernel granules), varying blasting angles (45° and 90°), blasting distances (7 and 10 cm), air pressures (2 and 2.5 bar), and nozzle diameters (0.5 and 0.8 mm) using an automated blasting cabinet. The results showed that corn cob granules and sodium bicarbonate were less effective than other media for removing paint layers at the application parameters. The samples were tested for hardness, gloss, and total color change. Samples exhibited a remarkable total color change and gloss increase when the blasting distance was increased from 7 cm to 10 cm, while their hardness decreased. The highest gloss value was obtained on surfaces blasted with a nozzle diameter of 0.5 cm. Surfaces blasted with a nozzle diameter of 8 mm, however, yielded the highest total color change and hardest values. © 2023, North Carolina State University. All rights reserved.
