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Cross-laminated timber (CLT) has become a popular engineered wood product due to its innovative properties and rapid development, which involves the use of various wood species and adhesives. This study aimed to assess the effect of glue application on the bonding strength, delamination, and wood failure of CLT made from jabon wood and bonded with a cold-setting melamine-based adhesive at three different rates: 250, 280, and 300 g/m2. The adhesive was composed of melamine–formaldehyde (MF) by adding 5% citric acid, 3% polymeric 4,4-methylene diphenyl diisocyanate (pMDI), and 10% wheat flour. Adding these ingredients increased the adhesive viscosity and decreased the gelation time. The CLT samples, made using cold pressing in the melamine-based adhesive at a pressure of 1.0 MPa for 2 h, were evaluated as per the standard EN 16531:2021. The results revealed that a higher glue spread resulted in a greater bonding strength, lower delamination, and a higher wood failure. The glue spread was shown to have a more significant influence on wood failure compared with delamination and the bonding strength. The application of 300 g/m2 glue spread (MF-1) on the jabon CLT led to a product that met the standard requirements. The use of modified MF in cold-setting adhesive produced a potential product that could be a feasible option for future CLT production in terms of its lower heat energy consumption.

A tree may receive compression and flexure combination, and the structural analysis governed by the building code may be capable of estimating the tree’s safety in the built environment. This study proposed to refer to the building code to check the tree dimension adequacy resisting the load. This study simplified the case by focusing only on the self-weight and ignoring the external loads; therefore, the buckling analysis of a slender tapered round column subjected to compression is advocated. Buckling occurs when the tree’s structure can no longer maintain its original shape. Euler and Ylinen’s buckling stress analysis (Method 1) calculated tree safety with a 95% confidence level. This study also applied the Greenhill formula (Method 2) to determine the critical height of a tree receiving the stem weight, then modified it to include the crown weight (Method 3). The three methods calculated the critical height to determine the safety factor (Sf), that is, the ratio of the actual tree height (H) to the 95% confidence level estimated critical height (Hcr). The safety factors were then categorized as unsafe (Sf < 1.00), safe (1.00 < Sf < 1.645), and very safe (1.645 < Sf). This study demonstrated that Method 1 is the most reliable and applicable among other methods. Method 1 resulted in no unsafe trees, 10 safe trees, and 13 very safe trees among the observed excurrent agathis (Agathis dammara). Meanwhile, among the decurrent rain trees (Samanea saman (Jacq.) Merr), 5, 31, and 14 were unsafe, safe, and very safe, respectively.

Indonesia is an agricultural country, and most of its territory is in the form of villages that have the potential to be developed as rural tourism centers. One area that has the potential to be developed into rural tourism centers is Panjalu, Indonesia. However, the sustainable development of rural tourism in Panjalu, Indonesia, still needs to be improved, so the community cannot enjoy the benefits of this rural tourism. This study aimed to analyze the sustainability strategy of rural tourism development in Panjalu, Ciamis, Indonesia. This study combined two methods, consisting of the Multi-Dimensional Scaling (MDS) and the Analytic Network Process (ANP). The MDS results show that rural tourism sustainability in Panjalu, Indonesia is included in the sufficient category, with a sustainability index of 57,998; 66,278; and 51,862, for ecological, socio-cultural and economic criteria, respectively. The MDS also analyzes which attributes are sensitive to the sustainability status. The most sensitive attributes for each criterion include Biodiversity for ecological criteria (RMS 2.224), Local Community Involvement for the social-culture criteria (1.147), and Livelihood Diversification for the economic criteria (1.245). These most sensitive attributes are, then, used as a reference for developing sustainable rural tourism development strategies. As a result, the strategic priority ranking for rural tourism in Panjalu, Indonesia is rural tourism based on culture and community development.

Jabon (Anthocephalus cadamba) is a fast-growing wood with low quality due to its low density and strength. The quality can be increased by modifying the wood through impregnation with various chemical compounds. In this study, jabon was impregnated with a solution of Fe and immersed in a strong base (NaOH) or a weak base (NH4OH) to form magnetite (Fe3O4) in-situ. This study analysed the use of NaOH and NH4OH in synthesising magnetic jabon wood and evaluated the wood’s characteristics. The impregnation process began with a vacuum of −0.5 bar for 0.5 h and then a pressure of 1 bar for 2 h. The samples subsequently underwent assessment of their dimensional stability, density, and characteristics. The results showed that impregnation with Fe solution followed by NaOH or NH4OH significantly affected the density and dimensional stability of the wood. The polymer weight gain was higher with NaOH, while the anti-swelling efficiency was higher with NH4OH. The density and bulking effect were increased, but the water uptake was decreased. Fourier transform infrared analysis showed the successful synthesis of magnetite. Scanning electron microscopy–energy-dispersive X-ray spectroscopy analysis revealed that magnetite covered the vessel fibre cell walls, and vibrating sample magnetometry analysis showed significant magnetic properties of the wood.

Rain tree (Samanea saman) is a dominant species commonly planted as a shade tree in urban landscapes in the tropics, including in Indonesia. This species is also targeted for routine inspection and monitoring within tree management systems. Management should particularly focus on tree health through assessment of tree growth conditions as well as tree stability. However, baseline information on the relationships of many key characteristics for the rain tree (e.g., growth, morphometrics, and biomechanics) is lacking. Therefore, an investigation was carried out to determine the relationship of morphometric parameters to tree growth, which included use of an acoustic tool to assess the elasticity of the tree stem. Fifty rain trees were selected for data collection and evaluated using stress wave velocity tools and visual morphometrics assessment. The results demonstrated that, in general, the trees had good vigor and stability. Statistical analysis showed a strong relationship between tree growth parameters and selected morphometric characteristics. The use of a nondestructive acoustic-based instrument enabled determining the modulus of elasticity, which provided equivalent results with the elasticity value obtained through a common method for determining tree stability. Only live crown ratio and tree slenderness parameters had a relationship with the dynamic modulus of elasticity. These results offer a means of measurement that is simpler, less expensive, and faster than current methods, although further testing is needed for different tree species and growth sites.

Ebony (Diospyros celebica Bakh.) is an endemic plant on Celebes (Sulawesi) island. Extractive compounds within ebony wood cause it to have durability, strength, and beautiful patterns. In this study, we used near-infrared (NIR) spectroscopy to discriminate between ebony wood samples, based on their origins at different growth sites on Celebes island, and to develop quantitative models to predict the extractive content of ebony wood. A total of 45 wood meal samples from 11 sites located in West, Central, and South Celebes were collected in this study. NIR spectral data were acquired from hot water and ethanol&ndash, benzene soluble extracts from ebony wood in this study. The extractive content of the ebony was 10.408% and 10.774% based on hot water solubility and treatment with ethanol&ndash, benzene solvent, respectively. Multivariate analysis based on principal component analysis&ndash, discriminant analysis revealed that ebony wood from West Celebes differed from most of the wood from South Celebes, however, it was only slightly different from ebony wood from Central Celebes based on NIR spectra data. These findings were in line with the extractive contents obtained. Partial least square regression models based on wood meal spectra could potentially be used to estimate the hot water and ethanol&ndash, benzene extractive contents from ebony wood.

Gewang (Corypha utan Lamk.) is one of the endemic palm species which has been used as a building material for many years in Indonesia. The objective of this study was to enhance the overall resistance of gewang wood to biological deterioration by using smoke treatment. Samples taken from different parts of the trunks, namely bottom, middle, and upper parts in a longitudinal direction and outer and inner parts in a transversal direction, were exposed to the smoking process. Discoloration, dry-wood termite (Cryptotemes cynocephalus) and fungi (Schizophyllumcommune) resistance of smoked samples were determined according to the Indonesian standard. Based on the findings in this work, discoloration of smoked specimens was more prominent than that of the unsmoked samples. Overall termite and decay resistance of smoked samples were enhanced and higher than those of unsmoked samples without any influence of longitudinal and transversal orientations within the trunks. It appears that smoking can be considered as a potential method to improve decay and termite resistances of gewang wood.