WOOD RESEARCH Volume 70, Number 1, 2025
CHUN-WON KANG, MASUMI HASEGAWA, and HARADHAN KOLYA

EFFECTS OF HOLE PERFORATION AND SURFACE CUTTING ON WOOD ELASTICITY USING ULTRASONIC AND VIBRATION METHODS

This study analyzed how hole perforation and surface cutting affect ultrasonic wave propagation velocity and resonant frequency in wood. While non-destructive evaluation techniques for wood elasticity are well-established, the specific influence of defects like holes and orthogonal cuts on wave behavior remains underexplored. This study aimed to fill this gap by assessing how these defects influence wave behavior and providing new insights into their impact on wood’s mechanical properties. Four softwood species and seven hardwood species were analyzed. In hardwood specimens, ultrasonic propagation velocity and resonant frequency were measured under increasing levels of hole perforation (9, 27, and 45 holes). In contrast, the effects of one and two orthogonal surface cuts were examined in softwood specimens. The results revealed that the ultrasonic propagation velocity decreased noticeably with an increasing number of holes. Meanwhile, resonant frequency exhibited only a slight decrease. In contrast, softwoods displayed minimal changes in ultrasonic velocity but notable reductions in resonant frequency due to surface cutting. This study highlights the differences in continuous wave propagation pathways associated with the two defect types and estimation methods, offering novel insights into wood evaluation techniques

WOOD RESEARCH Volume 69, Number 2, 2024
HARADHAN KOLYA, MASUMI HASEGAWA, KAZUHARU HASHITSUME, and CHUN-WON KANG

EFFECTS OF CHEMICAL AND PHYSICAL TREATMENTS ON BAMBOO CELL WALL STRUCTURE FROM ENGINEERING PERSPECTIVES

This study focuses on the effects of chemical treatment using polyethylene glycol (PEG) and physical treatment via steam explosion and microwave, with a comprehensive analysis using ATR-FTIR, X-ray diffraction, Keyence VR 6000 optical profilometer, and SEM. The aim is to elucidate alterations in bamboo cell walls following these treatments compared to untreated bamboo. The results reveal significant modifications in the chemical composition and crystalline structure of bamboo cell walls post-treatment. ATR-FTIR analysis indicates changes in functional groups, suggesting chemical interactions and modifications in the molecular arrangement of cell wall components. XRD analysis further corroborates these findings by revealing shifts in crystallinity and peak intensities, signifying structural rearrangements, as evidenced by optical images and SEM micrographs

WOOD RESEARCH Volume 68, Number 3, 2023
CHUN-WON KANG, KAZUHARU HASHITSUME, EUN-SUK JANG, and HARADHAN KOLYA

Relationship between Wood Anatomical Features and Surface Roughness Characteristics

This study aimed to investigate the relationship between surface roughness and anatomical features of wood in 15 different species of boards. Surface roughness was measured parallel and perpendicular to the wood grain using a surface profilometer, and anatomical features such as pore size and distribution were analyzed using microscopic techniques. The results showed that surface roughness perpendicular to the grain direction was consistently higher than that parallel to the grain direction for all wood samples. This difference in roughness was correlated with pore size and density. It shows that the larger pores and lower density lead to higher roughness perpendicular to the grain. The study also found that traditional hand planning methods (push and pull) produced a smooth surface finish, with no statistical differences in roughness.