Volume 21 Issue 3

The goal of this project was to examine the bamboo craft activities at Sentra Industri’s “Bambu Kencana” center and to suggest technological know-how for creating composite bamboo panels. The employees of the Mechanical Engineering Department at the Faculty of Engineering at Universitas Muhammadiyah Yogyakarta (UMY) Indonesia got the opportunity to visit the center in order to carry this out. Wulung (Gigantochloa atroviolacea), apus (Gigantochloa apus), petung (Dendrocalamus asper), ampel (Bambusa vulgaris ssp.), and tutul (Bambusa maculata) were among the species found on the bamboo plantation at Jangkang Kidul, Sentolo. Apus is the species utilized for webbing. Day beds, chairs, and sofa settees are the center’s primary focus. The entire production process is based only on the old-fashioned way of nailing and tying rattan furniture. A bamboo composite panel is manufactured and brought to the center. The Purwanto people in Jangkang Kidul, Sentolo, received instruction on how to make a bamboo composite. In an attempt to revive the bamboo craft activity, UMY created a prototype using the bamboo composite. By giving a discussion on the process of creating a bamboo composite, the community was introduced to a value-added technology.

Effects of deep eutectic solvents (DES) type and pretreatment time were evaluated relative to lignin extraction efficiency. Three major indicators, including lignin yield, solid residue proportion, and lignin purity, were investigated in detail at fixed molar ratios (1:8 and 1:8:1) and temperature (120 °C). The lignin yield gradually increased over 2 to 10 h, reaching 78.9% at 6 h in the choline chloride (ChCl)-formic acid (Fa)-oxalic acid (OA) system. The solid residue proportion continuously decreased to 36.4%, while maintaining lignin purity above 90% without significant variation. According to the lignin structure analysis, the basic aromatic structure of lignin, comprising syringyl (S) and guaiacyl (G) units, remained unchanged after treatment with the ternary DES system. The C/O ratio of carbon-rich macromolecular structures gradually increased with reaction time, and the carbon content of the samples exceeded 60%. This study provides a new approach to optimizing lignin extraction.

Rice husk (RH) is a global agricultural byproduct that poses environmental challenges due to disposal via open burning. This study contributes new findings on the RH valorization from Roban, Sarawak, establishing a highly effective hydrochloric acid (HCl) leaching protocol that yields amorphous silica with enhanced purity. The scientific significance lies in the successful optimization of treatment parameters to achieve superior silica oxide (SiO₂) purity of 97.26 wt%, and significantly enhanced whiteness index (WI) (74.4), demonstrating the efficiency of this protocol for regional variants. Furthermore, the structural analysis demonstrates the isolation of a predominantly amorphous phase, providing a critical baseline for utilizing Sarawak-specific agricultural waste in high-performance industrial applications. Energy dispersive X-ray (EDX) spectroscopy analysis confirmed the successful elimination of metallic impurities (P, K, Ca, and Fe), resulting in a reduced mass yield from 43.18% to 36.64%. Furthermore, HCl treatment narrowed the particle size distribution (SPAN: 1.66) and slightly reduced the mean diameter to 33.0 µm. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) analyses confirmed that both samples retained a stable amorphous structure. These results demonstrate that RH from this region is a viable, low-cost precursor for high-quality silica production, offering a sustainable alternative for agricultural waste management.

Leptoglossus occidentalis (Hemiptera: Coreidae), an invasive pest native to North America, causes significant damage to coniferous seed production worldwide. This study evaluated the effectiveness of contact spray and Arborjet trunk injection methods for controlling L. occidentalis in black pine (Pinus nigra) seed orchards in Bursa-Karacabey, Türkiye. Abamectin (18 g/L), as insecticide, was applied to plots of 50 trees each in 2025, and 300 cones were harvested in November 2025 for seed fill and empty cone analysis. Statistical analyses included Kruskal-Wallis and Wilcoxon tests with Bonferroni correction. Seed fill percentages were 9.7% (control), 33.9% (spray), and 52.8% (Arborjet trunk injection). The Arborjet method yielded approximately 5.6 times higher seed fill than the control with the lowest coefficient of variation (17.2%). Empty cone ratios differed significantly among groups (Fisher’s exact test, P < 0.001), with 0% in the Arborjet group versus 12% in the spray group. Treatment type explained 63.3% of total variance (η² = 0.633), with very large pairwise effect sizes (Cohen’s d = 1.33 to 3.42). These results demonstrate that systemic trunk injection should be prioritized over contact spray in seed orchards and gene conservation areas.