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Oil palm (Elaeis guineensis Jacq.) plantations in Indonesia are increasing over the past few years. After economic productivity, however, the unproductive oil palm trunks are felled and mostly go to waste, especially the inner part of the oil palm trunk (IOPT). There are several modification methods to utilize IOPT, such as impregnation and densification. Methylene diphenyl diisocyanate (MDI) is a common resin used for impregnation in composite industries because it is non-toxic and has excellent physical and mechanical properties but it has never been applied for the impregnation of IOPT. This study aimed to analyze the effect of densification on the physical and mechanical properties of the inner part of oil palm trunk (IOPT) impregnated using methylene diphenyl diisocyanate (MDI) resin to obtain valuable information regarding the efficient utilization of unproductive oil palm trunks. IOPT was densified and compregnated with compression ratios (CRs) of 20% and 30%. The physical properties (density, moisture content (MC), and water absorption (WA)) and mechanical properties (modulus of elasticity (MOE), modulus of rupture (MOR), and hardness) of the compregnated samples were better than those of the densified samples. The density and mechanical properties at CR 30% were higher than those at CR 20%. The improvements in density, MC, and WA of the compregnated IOPT with CR 30% were 127%, 54%, and 70%, respectively, compared to that in untreated IOPT. Furthermore, improvements in the MOE, MOR, and hardness of the compregnated IOPT with CR 30% were 489%, 379%, and 393%, respectively. The mechanical properties of the compregnated IOPT at CR 20% and 30% increased two- to three-fold from strength class V in control IOPT to strength class III in compregnated IOPT with CR 20% and to strength class II in compregnated IOPT with CR 30%, respectively. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate and compare the fracture morphology in hardness test of compression (CW), lateral (LW), and opposite woods (OW) of Pinus merkusii and Agathis loranthifolia growing in Indonesia. The hardness of the transverse, radial, and tangential surfaces was examined using Brinell's method, according to the Korean standard. The fracture surfaces of hardness tested samples were observed by scanning electron and optical microscopy. On all surfaces from both species, CW showed the highest hardness, and no significant differences were detected between LW and OW. On the transverse surface, CW of P. merkusii showed brittle-fractured cell wall, while that of A. loranthifolia displayed smooth cell wall. CW of both species showed intercellular and intrawall failures and a narrow lumen opening. LW of both species and OW of P. merkusii showed folded earlywood tracheids with a crack, whereas in the latewood of P. merkusii, LW and OW displayed smooth cell wall and a narrow lumen opening. OW of A. loranthifolia showed collapsed cell wall. On the radial surface, CW of both species showed buckling tracheids in the tangential direction. LW and OW of both species exhibited shortening earlywood tracheids with folded cell walls, while LW and OW of P. merkusii exhibited buckling latewood tracheids in the radial direction. On the tangential surface, buckling tracheids occurred near the fractured rays in all parts of both species. In conclusion, CW exhibited distinctive hardness and fracture morphologies compared with LW and OW in P. merkusii and A. loranthifolia; in addition, hardness and fracture morphology differed between the two species. [ABSTRACT FROM AUTHOR]

Balsa and kapok fibers are by-products of community plantations. Both fibers have not been optimally utilized in Indonesia. The high holocellulose content and low lignin content of these fibers indicate the potential to be used as a nanocellulose raw material with a simple extraction. The objective of this study was to extract cellulose nanocrystals (CNCs) from balsa and kapok fibers through a direct extraction without pre-treatment. CNCs from balsa and kapok fibers were prepared by a one-step procedure with ammonium persulfate solution (APS) at concentrations of 1, 1.5, and 2 mol/L. The CNCs were characterized by determining their morphology, functional groups, crystallinity, and thermal stability using transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and thermogravimetric analysis, respectively. The results showed that the diameter of the CNCs was in the range of 1.25–11.87 nm depending on the APS concentration and the fiber type. APS dissolved the lignin and hemicellulose, which led to an increase in the CNCs crystallinity with an increasing APS concentration. The decrease in the thermal stability of the CNCs was thought to be due to the increase in the surface area of the particles and the presence of carboxyl groups in the CNCs. This research revealed that balsa and kapok fibers could be used as raw materials to produce nanocellulose in one-step using ammonium persulfate. [ABSTRACT FROM AUTHOR]

The domestication of Indonesian cattle was investigated through a study of their genetic diversity, up to the genome level. Little documentation exists regarding the history of domestication of Indonesian cattle and questions remain despite a growing body of molecular evidence. In this study, we genotyped seven Indonesian cattle breeds using an Illumina BovineSNP50 Bead Chip to provide insight into their domestication and demographic history in a worldwide population context. Our analyses indicated the presence of hybrid cattle, with Bos javanicus and Bos indicus ancestries being most prevalent, as well as purebred cattle. We revealed that all the breeds were interconnected through several migration events. However, their demographic status varied widely. Although almost all the Indonesian cattle had an effective population size higher than the minimum level required to ensure breed fitness, efforts are still needed to maintain their genetic variability and purity., Competing Interests: The authors have declared that no competing interests exist.