Technical University in Zvolen OJS
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PRODUCTION OF BINDER-FREE BOARDS FROM BIODEGRADED ABIES SIBIRICA WOOD
Get PDFThe aim of this paper is to investigate the feasibility of obtaining binder-free wood boards from rotted wood at the final stages of biodegradation. The rot-affected wood of Abies sibirica harvested from a stand killed by exposure to Polygraphus proximus Blandford was used as a subject of research. The wood boards from rotted wood were produced by wet hot pressing. The wood pulp was prepared by hydrodynamic treatment in a rotary pulsation disperser. The obtained wood boards with a density of 800 ± 20 kg/m3 and a thickness of 8 mm have an ultimate static bending strength of 28 MPa, modulus of elasticity (MOE) of 3.5 GPa, ultimate tensile strength perpendicular to the plate of 0.92 MPa, swelling in terms of thickness of 4.61 % in 24 hours. The boards dried after swelling tests retained 96% of their initial strength. The boards produced of biodegraded wood correspond to the EN622-3 semihard fibreboards (MB) in terms of mechanical parameters and are significantly superior in terms of water resistance
UTILIZING COLLABORATIVE LEARNING TO ENHANCE MOTIVATION, FOSTER INCLUSIVITY AND SUPPORT WELL-BEING IN LSP
Get PDFIn the evolving landscape of Foreign Language Teaching, inclusivity is paramount, also in Language for Specific Purposes (LSP). Departing from traditional approaches, educators emphasize dynamic learning environments where students actively engage with tailored content. Collaborative learning, rooted in constructivist principles, serves as a cornerstone for effective language acquisition within specialized contexts. This article explores the theoretical framework of collaborative learning and its application in LSP, presenting a case study to illustrate its impact on student well-being and learning outcomes. The study employs a mixed-methods approach to provide a comprehensive understanding of student experiences and perceptions. Results indicate a positive correlation between collaborative learning practices and student engagement, motivation, and sense of community. Proactive measures are discussed to address challenges such as student stress during presentations, emphasizing ongoing reflection and adaptation in pedagogical practices. Overall, the findings highlight the transformative potential of collaborative learning in promoting inclusive education and enhancing student outcomes within specialized language contexts
THE DRAMA OF MIGRATION AND IDENTITY: AGAINST THE BACKDROP OF AUSTRIAN ANTI-HOMELAND LITERATURE AND THE NOVEL DRAMA
Get PDFThis paper examines the novel Drama (2023) by Austrian author Arad Dabiri through the lens of Austrian anti-heimat (anti-homeland) literature and the socio-psychological implications of migration, identity conflict, and trauma. Drawing on the Vienna School of Critical Discourse Analysis and attachment theory, the study explores how Dabiri portrays Vienna not as a safe homeland but as a contested, alienating space loaded with both personal and political meaning. The protagonist's psychological descent is portrayed through a dramatic structure, resembling classical theatre in its escalation of conflict and absence of catharsis. The city becomes not only a setting but a narrative agent—an active force shaping the protagonist’s fragmentation. By situating Drama within the tradition of post-1945 Austrian literature that challenges mythologized national identity, this article reveals how contemporary Austrian migrant narratives continue to unsettle dominant cultural discourses. Ultimately, Drama does not offer redemption, but insists on the persistence of unresolved memory, making visible the internalized fractures of a society still grappling with the boundaries of belonging
INFLUENCE OF THE CUTTING MODE ON THE NOISE EMISSION LEVEL DURING LONGITUDINAL-PLANNER MILLING OF LINDEN AND BEECH WOOD
Get PDFThe change in noise emissions generated during longitudinal flat milling of solid wood specimens using a knife shaft with spirally arranged flat knives is investigated in the paper. The influence of the feed rate (Vf) and the thickness of the cut-out layer (h) on the change in the A-weighted sound pressure level in dB(A) was determined. For the purpose of the study, specimens from beech and linden wood with widths (B) of 50, 100 and 150 mm were used. Based on the performed measurements, graphical dependencies illustrating the influence of the investigated factors on the noise emission levels were derived. The results confirmed the predicted influence of the feed rate (Vf) on the changes in the noise emission levels as follows: the Vf increased from 88.3 dB(A) to 92 dB(A) during processing beech wood specimens, and from 87.1 dB(A) to 89.9 dB(A) when processing linden wood specimens. Depending on the thickness of the cut-out layer (h), the sound pressure level varies within the range from 90.5 dB(A) to 97.3 dB(A) when processing beech wood specimens and from 86.2 dB(A) to 88.6 dB(A) for linden wood specimens. For the practical applicability of the obtained results and in order to ensure lower noise emission levels consistent with the maximum permissible sanitary and hygienic standard of 85 dB(A), recommendations for the optimal values of the feed rate (Vf) and the thickness of the cut-out layer (h) were made
ENERGY DOSE AND SPECIFIC CUTTING ENERGY IN CO₂ LASER CUTTING OF SOLID AND ENGINEERED WOOD MATERIALS
Get PDFThe energy requirements of CO₂ laser cutting for three solid wood species (spruce, oak, and beech) and three engineered wood-based materials (pine plywood, beech plywood, and high-density fiberboard) are examined in this study. Energy dose (Ed) and specific cutting energy (Ec) were calculated for each material under selected laser power and feed rate combinations. The goal was to achieve a kerf width of 300 µm, consistent with the geometric tolerances of ISO 9013:2017. Results show that Ed increases with material density, while Ec reveals additional influences, including anatomical structure and bonding in engineered products. Oak exhibited the lowest Ec despite a relatively high density, while HDF and beech plywood showed the highest values. These findings suggest that material density can inform initial laser parameter selection, but cutting efficiency also depends on how energy interacts with structure and composition. The observed relationships between density and Ed, and between Ed and Ec, provide a framework for refining processing settings based on material characteristics
MEASUREMENT BOUND WATER MAXIMUM MOISTURE CONTENT AND DIFFUSION COEFFICIENT DETERMINATION OF BLOWN CELLULOSIC INSULATION MATERIAL IN LABORATORY CONDITIONS
Get PDFMechanical properties, dimensional stability, and biological durability are affected by moisture in timber structures; however, moisture is necessary for hygroscopic insulation materials. With high moisture content, wood elasticity is reduced, corrosion of connectors is promoted, thermal conductivity and heat storage capacity are increased. Thanks to hygroscopic fibers, moisture is stored and redistributed in blown cellulose insulation, the hydrothermal balance within timber walls is enhanced. A laboratory method to determine the diffusion coefficient under variable surface fluxes is developed, and the maximum bound water content is measured using Archimedes’ principle. 40 cm thick test specimens under controlled interior and exterior conditions were tested in the experiments. Moisture content fluctuation was monitored over three months. The diffusion coefficient was derived from Fick’s law and from conservation principle using the inverse method. Results show a decreasing diffusion coefficient that stabilizes over time and a maximum bound water content of 34%. The findings indicate that effective insulation materials must combine a high diffusion coefficient and water storage capacity to manage water condensation and preserve structural durability
BEARINGS LOAD ON A CIRCULAR SAW MILL DURING CUTTING BEECH WOODS
Get PDFThe influence of some technological factors on the magnitude of vibrations of the cutting mechanism in a circular saw mill is presented in the study. The cutting mechanism is driven by four V-belts with a “B” section. During operation, vibro-acceleration was measured using specialized measurement equipment described in the methodology. Measurements are made at four points in the radial direction. Two of them are located near the cutting tool (Ax and Ay) of the machine, and the other two (Bx and By) are near the belt pulley. The results of the experiment are presented graphically. The experiments were carried out at a rotation frequency of 1014 min-1. During the experiments, beech trees were cut down. During the research, attention was paid to some technological factors, including the feed speed of the processed material, ranging from 20 m/min to 60 m/min, and the wood thickness, ranging from 80 mm to 240 mm. The study is aimed at improving the reliability and efficiency of a machine as well as ensuring the accuracy and quality of products
MOISTURE CONDUCTIVITY AND DENSITY OF INDUSTRIAL WOODS: A STUDY FOR EFFECTIVE DRYING
Get PDFAn analysis of the physical properties of the main industrial tree species revealed significant variation across growing regions with different climatic conditions. For drying sawn timber products, convection chambers equipped with automatic systems with pre-set schedules designed for tree species native to the countries where dryers are manufactured are most widely used. It does not always lead to positive results. Adjusting the parameters of the modes requires the density and moisture-conductivity coefficients for industrial tree species. The dependence of moisture conductivity coefficients in the transverse directions of moisture movement on temperatures in the 25 °C – 80 °C range was determined. Adequate regression equations for the dependence of moisture conductivity coefficients on temperature in the tangential and radial directions were obtained. The values of the average basic density of these tree species originating from different regions and its dispersion determined experimentally were as follows: pine 414 kg∙m-3 ± 11%; alder 448 kg∙m-3 ± 9%; oak 569 kg∙m-3 ± 10%; ash 640 kg∙m-3 ± 6%; hornbeam 667 kg∙m-3 ± 7%. These values were used to determine the analytical dependence of the moisture conductivity coefficients on the basic density and its dissipation, which is necessary for developing optimal schedules of drying sawn timber by adequately modelling convection drying and predicting process quality