Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleYalnız künye2026Scopus SJRQ4SURFACE ROUGHNESS AND SHORE-D HARDNESS OF SIX TROPICAL HARDWOODS; [RUGOSIDADE DA SUPERFÍCIE E DUREZA SHORE-D DE SEIS MADEIRAS TROPICAIS]; [RUGOSIDAD SUPERFICIAL Y DUREZA SHORE-D DE SEIS MADERAS TROPICALES]
Ayata, Umit; Domingos, Idalina; Ferreira, José; Cruz-Lopes, Luísa; Esteves, Bruno
Introduction: This study investigates the Shore-D hardness and surface roughness characteristics of six tropical wood species: Canelo (Nectandra spp.), Limbali (Gibertiodendron dewevrei), Difou (Morus mesozygia), Curupay (Anadenanthera macrocarpa), Ebiara (Berlinia bracteosa), and Zwarte kabbes (Diplotropis martiusii), aiming to assess their suitability for high-performance applications. Objective: To evaluate how wood species and sanding processes influence the mechanical properties and surface quality of selected tropical woods. Methods: Samples were conditioned and sanded using abrasives of different grit sizes (80, 100, 120, 150, and 180). Surface roughness parameters Ra, Rq, and Rz, as well as Shore-D hardness, were measured. Statistical analyses were performed using ANOVA and Duncan’s test. Results: Statistical analysis revealed that abrasive grit size significantly affected surface roughness (p < 0.001), with finer grits producing smoother surfaces. Wood species also had a significant effect on both roughness and hardness. Sanding had the greatest influence on Ra, Rq, and Rz parameters. Ebiara exhibited the smoothest surface, while Curupay showed the highest hardness (74.65). Conclusion: Surface roughness is primarily influenced by sanding grit, whereas hardness is determined by wood species. The results emphasize the importance of tailoring sanding procedures to the wood species in order to optimize surface quality and mechanical performance in industrial and decorative applications.
- MakaleYalnız künye2026Scopus SJRQ4CORRELATION BETWEEN THE CHEMICAL COMPOSITION OF WOOD AND THE INCREASING OF ITS CALORIFIC VALUE THROUGH HEAT TREATMENT; [CORRELAÇÃO ENTRE A COMPOSIÇÃO QUÍMICA DA MADEIRA E O AUMENTO DO PODER CALORÍFICO ATRAVÉS DO TRATAMENTO TÉRMICO]; [CORRELACIÓN ENTRE LA COMPOSICIÓN QUÍMICA DE LA MADERA Y EL AUMENTO DE SU PODER CALORÍFICO MEDIANTE TRATAMIENTO TÉRMICO]
Domingos, Idalina; Ferreira, Miguel; Ferreira, José; Dulyanska, Yuliya; Ayata, Umit; Esteves, Bruno
Introduction: The greatest importance of biomass lies in its Higher Heating Value (HHV), when considered for energy production. The calorific value is significantly affected by the changes in the chemical composition of the wood that occur during heat treatment. Objective: To understand the effect of heat treatment on the calorific value of the chemical constituents of two hardwoods: Sapelli and chestnut, and two softwoods: Scots pine and Siberian pine. Methods: The calorific value was determined by a Parr calorimeter – model 6400. The content of extractives was determined by successive Soxhlet extraction using about 3 g of each sample and 150 ml of dichloromethane, ethanol, and water as solvents. The extractives content was determined in accordance with TAPPI 204, and insoluble lignin by the Klason method Tappi T 222 om-02. For the determination of holocellulose, the acid chlorite method was used. Results: The calorific value of untreated wood ranged from 18.98 MJ/kg for chestnut to 20.35 MJ/kg for Siberian pine. Heat treatment resulted in an increase in the calorific value for most of the wood samples studied. Conclusion: The rise in HHV observed during heat treatment in softwoods and hardwoods is mainly due to the increase in lignin content, although dichloromethane extractives also play an important role.
- MakaleAçık Erişim2022Scopus SJRQ2EXTRACTIVES IN THERMALLY MODIFIED TROPICAL HARDWOODS
Esteves, Bruno; Ayata, Umit; Cruz-Lopes, Luísa; Brás, Isabel; Ferreira, José; Domingos, Idalina
Chemical composition of wood is known to change during thermal treatments. Two species grown in Turkey, afrormosia (Pericopsis elata) and duka (Tapirira guianensis) were heat treated according to Thermowood® method. Lignin, cellulose, hemicelluloses and extractives in dichloromethane, ethanol and water were determined. Wood extracts were analysed by gas chromatography with mass detection and existing compounds were identified by NIST17 database. Results show that hemicelluloses and cellulose content decreased for both heat-treated woods along the treatment while lignin percentage increased. The analysis of extractives has shown several compounds normally associated to lignin thermal degradation that increased along the treatment. At the same time several compounds associated to carbohydrate thermal degradation were found in all the extracts for both heat-treated woods. These founding have allowed the understanding of the degradation pattern of wood during thermal modification. There was not much difference between afrormosia and duka woods structural compounds behaviour along thermal modification. However, the variation of the amount of extractives along the treatment depended on the species.
AtıfScopus20WoS20OpenAlex16
İncele - MakaleAçık Erişim2020Scopus SJRQ2Calorific power improvement of wood by heat treatment and its relation to chemical composition
Domingos, Idalina; Ayata, Umit; Ferreira, José; Cruz-Lopes, Luisa; Sen, Ali; Sahin, Sirri; Esteves, Bruno
Chemical composition influences the calorific power of wood, mainly due to the calorific power of structural compounds and extractives. Heat treatment changes the chemical composition of treated wood. This work studies the relationship between chemical composition and calorific power improvement by heat treatment. Samples were heat-treated by the ThermoWood process ® for 1 h and 2 h. High heating value (HHV) and chemical composition; lignin, cellulose, hemicelluloses and extractives in dichloromethane, ethanol, and water were determined. The HHV of untreated wood ranged between 18.54-19.92 MJ/kg and increased with heat treatment for all the tested species. A positive linear correlation was found between HHV and Klason lignin (R2 = 0.60). A negative trend was observed for holocellulose, cellulose, and hemicelluloses content against HHV, but with low determination coefficients for linear regression. The best adjust for polysaccharides was found for hemicelluloses content. A positive correlation could be found for dichloromethane extractives (R2 = 0.04). The same was obtained in relation to ethanol extractives with R2 = 0.20. For water and total extractives, no clear positive or negative trends could be achieved. The results showed that the HHV of wood increased with heat treatment and that this increase was mainly due to the increase in lignin content.
AtıfScopus32WoS27OpenAlex38İncele - MakaleAçık Erişim2019İzmir’de Yetişen İğde (Elaeagnus angustifolia L.) Odununda Bazı Fiziksel ve Mekanik Özelliklerinin Belirlenmesi
Bal, Bekir Cihad; Ayata, Umit
Odun hammaddesi önemli mühendislik malzemelerinden birisidir. Özellikle, yenilenebilir olması, ucuz olması, kolay temin edilebilmesi, kolay işlenmesi, çevre dostu olması ve estetik bakımdan tercihe edilmesi önemli üstünlüklerindendir. Odunun kullanım yerine karar verirken, onun bazı teknolojik özelliklerinin iyi bilinmesi gerekmektedir. Yapılan önceki çalışmalarda, iğde odununun fiziksel ve mekanik özellikleri üzerine yeterli çalışmaya ulaşılamamıştır. Bu nedenle, bu çalışmada, İzmir’de yetişen iğde (Elaeagnus angustifolia L.) odununa ait bazı fiziksel ve mekanik özellikleri araştırılmıştır. Elde edilen bulgulara göre; hava kurusu rutubet değeri %9,93, hava kurusu yoğunluk (D12) 536 kg/m3, tam kuru yoğunluk (Do) 507 kg/m3, teğet yönde genişleme (αt) %5,90, radyal yönde genişleme (αr) %3,24, boyuna yönde genişleme (αı) %0,30, hacmen genişleme (αv) %9,44, lif doygunluğu noktası (LDN) %18,63. Şok direnci 0,389 kgm/cm2, eğilme direnci 61,12 N/mm2 ve elastikiyet modülü tayini 4663 N/mm2, janka sertlik değeri teğet, radyal ve enine yüzeyler için sırasıyla 40,23 N/mm2, 40,10 N/mm2 ve 58,74 N/mm2 olarak tespit edilmiştir.
AtıfOpenAlex4TR Dizin3
İncele - MakaleAçık Erişim2019Scopus SJRQ2Determination of Thermal Conductivity Properties in Some Wood Species Obtained from Turkey
Çavus, Vedat; Sahin, Siri; Esteves, Bruno; Ayata, Umit
With the increased awareness of thermal insulation of buildings, the knowledge of thermal conductivity of non-structural materials applied for roughing, cladding or flooring has become more important. The objective of this study was to investigate the thermal conductivity of 31 different wood species originated from the region of Izmir in Turkey. Thermal conductivity of air dried boards was determined in accordance to ASTM 5334 standard which measures this property on the interior of wood rather than on the surface. Thermal conductivity varied from 0.090 to 0.197 W/ mK. The highest thermal conductivity was obtained for oak and the lowest for Canadian poplar. A linear relation was obtained between wood density and thermal conductivity.
AtıfWoS42OpenAlex58İncele