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    Changes in surface and mechanical properties of heat treated wood during natural weathering
    (Elsevier Sci Ltd, 2014) Dizman Tomak, Eylem; Ustaomer, Derya; Yildiz, Sibel; Pesman, Emrah
    In this study, it was aimed to investigate the changes in moisture content, color, surface roughness, compression strength parallel to grain, modulus of rupture and modulus of elasticity of heat treated ash, iroko, Scots pine and spruce wood species during natural weathering for two years. Samples were removed at 6-month intervals for performance evaluation, and test results were compared with the controls. Moisture content of heat treated samples was found to be lower than that of control samples for all exposure periods. Heat treatment significantly changed original wood color as well as weathering factors. Wood surfaces become rougher within longer weathering exposure period. Natural weathering factors caused a decrease for all strength properties. Reduction rate for strength properties of heat treated samples was relatively lower than that of control samples. Heat treatment also seemed to improve color stability and surface quality of samples after weathering. (C) 2014 Elsevier Ltd. All rights reserved.
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    Effects of Flotation Deinking on the Removal of Main Colors of Oil-Based Inks from Uncoated and Coated Office Papers
    (North Carolina State Univ Dept Wood & Paper Sci, 2013) İmamoğlu, Sami; Karademir, Arif; Pesman, Emrah; Aydemir, Cem; Atik, Celil
    This paper presents the results of trials to evaluate the color-stripping behaviour of offset printing colors and the effect of coating on deinking performance. Oil-based four-color inks were separately printed as base printing on coated and uncoated white poster paper, and then extensive pulping and deinking processes were carried out. Standard offset printings were conducted on paper samples using cyan, magenta, yellow, and black colors (CMYK), and the effects of deinking efficiency on the removal of each color were analysed. The pulps were made at Micro-Maelstrom Laboratory Pulper at specified conditions with and without bleaching agents. Formamidin sulfinic acid and hydrogen peroxide formulation were used as reductive and oxidative bleaching agents, respectively. Flotation deinking and thickening of pulp were practiced using Degussa flotation and thickening cell. The changes in the optical properties, such as brightness, whiteness, and color value (CIE L*, a*b*) of deinked pulp were determined. It was found that optical properties of color-stripped pulps from coated papers were better than that of uncoated office papers. However, yield was quite low in coated papers since fillers were lost during flotation process. Cyan color was found to be the most difficult one in four main color printing inks stripping out in deinking process.
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    Hybrid thermoplastic composite reinforced natural fiber and inorganic filler
    (Walter De Gruyter Gmbh, 2023) Cavdar, Ayfer Donmez; Torun, Sevda Boran; Pesman, Emrah; Angin, Naile; Ertas, Murat; Mengeloglu, Fatih
    This chapter summarizes the recent studies on natural and synthetic short fiber-filled thermoplastic-based hybrid composites. This review will provide information on the manufacturing processes and the structure, and the properties of hybrid thermoplastic composites, in separate sections. It supplies data on physical, mechanical, morphological, rheological properties, and thermal and flammability characterizations of select hybrid composites. This chapter underlines the importance of hybrid thermoplastic composite in achieving predetermined material performances. Recent studies have proven that the hybridizations of natural fiber and inorganic filler might provide exceptional and promising features.
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    SURFACE PROPERTIES OF BAMBOO AND SCOTS PINE IMPREGNATED WITH BORON AND COPPER BASED WOOD PRESERVATIVES AFTER ACCELERATED WEATHERING
    (Univ Bio-Bio, 2016) Baysal, Ergun; Dizman Tomak, Eylem; Topaloglu, Elif; Pesman, Emrah
    In this study, we investigated the color, gloss and surface roughness of bamboo (Phyllostachys bambusoides) and Scots pine (Pinus sylvestris) samples impregnated with boron and copper based preservatives during accelerated weathering from 168 h to 672 h. Tanalith-E, ACQ, wolmanit-CB were used as copper-based chemicals, while a mixture of boric acid and borax (7:3; w/w) was used as the boron compound. Results showed that retention values of bamboo samples were lower than the retention values of Scots pine samples probably due to the bamboo's anatomical structure and penetration characteristic. Bamboo surfaces became rougher and darker after impregnation and accelerated weathering compared to initial surfaces. Longer accelerated weathering periods seemed to have not a considerable effect on surface roughness of bamboo samples impregnated with copper based preservatives. Gloss of impregnated Scots pine samples increased with longer accelerated weathering period while gloss of bamboo samples decreased slightly with longer accelerated weathering period. Wolmanit-CB seemed to be most effective wood preservative for hindering color change and ensuring smooth surfaces after accelerated weathering. Color changes caused by accelerated weathering tended to be greater for impregnated bamboo samples than impregnated Scots pine samples.
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    Testing the durability of copper based preservative treated bamboos in ground-contact for six years
    (Springer, 2022) Tomak, Eylem D.; Topaloglu, Elif; Ermeydan, Mahmut A.; Pesman, Emrah
    In this study, durability of bamboo samples in terms of the variability of location along culm height (top, middle and bottom) were evaluated in a ground-contact field test for six years in comparison to Scots pine and beech wood samples. Bamboo and wood samples were treated with Wolmanit-CB (CCB) and Tanalith-E (Tan-E) solutions, and then were installed in a field located in the North-West of Turkey. The decay resistance of samples was assessed by weight loss, and compared by SEM observations and FTIR analysis. Furthermore, chemical leaching from the samples was detected by ICP-OES after the test. Results showed that un-treated bamboo and wood samples had a very low durability such that weight losses were found as 64-80% for bamboo and 57-63% for wood samples. The SEM micrographs showed the characteristics decay patterns of soft-rot type I and brown-rot fungi in the parenchyma cells, vessels and fibers in vascular bundles. Fungal hyphae within the cell walls resulted in the gradual breakdown of the cell wall layers. FTIR analysis revealed the mechanism of the biodegradation, which indicates the reduction of carbohydrate content. The weight loss in CCB and Tan-E treated bamboo samples was reduced as 20-45% depending on bamboo height parts, but the wood preservatives did not ensure sufficient resistance for six years against soil degrading organisms since more than half of the chemical amount leached out from the bamboos to soil. Weight losses were well confirmed by chemical leaching rates for both CCB and Tan-E. It was observed that the lower parts of the culm were more durable, which was also in accordance with ICP-OES and SEM analysis. Copper-based preservatives seemed to be more efficient in pine and beech wood samples than bamboos since the impregnability of bamboo was much lower than that of wood.