Taxonomic and genetic assessment of captive White-Handed Gibbons (Hylobates lar) in Peninsular Malaysia with implications towards conservation translocation and reintroduction programmes

Conservation translocation and reintroduction for the purpose of repopulating and reinforcing extirpated or depleted populations has been recognised as an important conservation tool, particularly for gibbon conservation in the immediate future. Feasibility assessments involving multiple factors, including taxonomic and genetic assessment of rescued and captive gibbons, are imperative prior to translocation and reintroduction programmes. In this study, we attempt to determine the subspecies and origin of captive Hylobates lar, White-handed gibbons, from Peninsular Malaysia to assist in future translocation and reintroduction programmes. A total of 12 captive and rescued H. lar samples were analysed using the control region segment of mitochondrial DNA. Sequence analyses and phylogenetic trees constructed using neighbour-joining, maximum likelihood, Bayesian inference, and network methods congruently differentiate all 12 captive individuals used in this study from other H. lar subspecies suggesting that these individuals belong to the H. lar lar subspecies. In addition, two populations of H. l. lar were observed: (1) a southern population consisting of all 12 individuals from Peninsular Malaysia, and (2) a possible northern population represented by three individuals (from previous studies), which might have originated from the region between the Isthmus of Kra, Surat Thani-Krabi depression, and Kangar-Pattani. Our findings suggest that the complete control region segment can be used to determine the subspecies and origin of captive H. lar

PHYSICAL CHARACTERIZATION OF POLYURETHANECLAY COMPOSITE DOPED WITH TREATED AND UNTREATED PU WASTE AS FILLER FOR SUBGRADE LAYER APPLICATIONS

One of the most efficient ways to enhance the geotechnical characteristics of soils is to use polyurethane waste as a filler. In this study, the PU waste was soaked in a 0.05 M sodium hydroxide (NaOH) solution as an alkaline cleaner before being sieved to a size of 300 m. Then, the PU waste as filler was dried in microwaves and a drying oven. The PU clay composite samples were prepared at 0%, 2.5%, and 5% of PU waste filler loading namely PU waste untreated (PU-CCUn), PU waste treated by microwave (PU-CCTW), and PU waste treated by the oven (PU-CCTO), respectively. Fourier Transform Infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and water absorption was used to examine the physical characteristics of PU clay composite with treated and untreated PU waste filler loading. According to the results, the functional group of PU clay composite samples shows no significant changes with the drying treatment. However, from SEM image exhibited the PU waste particle was mixed successfully in clay. The PU clay composite shows that 12% more water was absorbed by PU-CCUn than by PU-CCTO and PU-CCTM due to the bigger pore sizes. In summary, the risk of overheating and burning the PU waste as filler powder with the microwave processing method makes the prospective PU-CCTO the best potential in comparison to PU-CCUn and PU-CCTM. This demonstrated the effectiveness of the drying oven treatment method and its superior wettability to that of the microwave. In the future, it is recommended to utilize PU waste as filler that has been dried at a variable ratio of up to 10%

PHYSICAL CHARACTERIZATION OF POLYURETHANECLAY COMPOSITE DOPED WITH TREATED AND UNTREATED PU WASTE AS FILLER FOR SUBGRADE LAYER APPLICATIONS

One of the most efficient ways to enhance the geotechnical characteristics of soils is to use polyurethane waste as a filler. In this study, the PU waste was soaked in a 0.05 M sodium hydroxide (NaOH) solution as an alkaline cleaner before being sieved to a size of 300 m. Then, the PU waste as filler was dried in microwaves and a drying oven. The PU clay composite samples were prepared at 0%, 2.5%, and 5% of PU waste filler loading namely PU waste untreated (PU-CCUn), PU waste treated by microwave (PU-CCTW), and PU waste treated by the oven (PU-CCTO), respectively. Fourier Transform Infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and water absorption was used to examine the physical characteristics of PU clay composite with treated and untreated PU waste filler loading. According to the results, the functional group of PU clay composite samples shows no significant changes with the drying treatment. However, from SEM image exhibited the PU waste particle was mixed successfully in clay. The PU clay composite shows that 12% more water was absorbed by PU-CCUn than by PU-CCTO and PU-CCTM due to the bigger pore sizes. In summary, the risk of overheating and burning the PU waste as filler powder with the microwave processing method makes the prospective PU-CCTO the best potential in comparison to PU-CCUn and PU-CCTM. This demonstrated the effectiveness of the drying oven treatment method and its superior wettability to that of the microwave. In the future, it is recommended to utilize PU waste as filler that has been dried at a variable ratio of up to 10%

Effect of Buoyancy, Compressive Strength, and Shear Strength of Polyurethane-Clay Composite (PU-CC) Doped with Polyurethane Filler Waste in Soft Clay Application

The application of polyurethane waste as a filler is one of the most cost-effective strategies for enhancing the geotechnical properties in soils. The PU waste from manufacturing economies was prepared with alkaline solutions by submerging into a 0.05 M sodium hydroxide (NaOH) before sieving to 300m sizes. The PU waste as filler was prepared using two heat exposure from microwaves and drying ovens at 60°C and left for 3 hours. Then, the treated and untreated Polyurethane-Clay Composite (PU-CC) was prepared at the different ratios of PU waste filler (2.5%, 5%, 7.5%, and 10%). The physical properties of treated and untreated Polyurethane-Clay Composite (PU-CC) were examined utilizing buoyancy force, unconfined compressive strength (UCS), and direct shear strength, respectively. The result exhibited that the PU-CCTO has the highest buoyancy force at 10% of PU-CCTO10 samples at 50%, followed by 45% of PUCCTM10 and 8% of PU-CCUN2.5. The UCS and shear strength of PU-CCTO10 are evidently the highest at 300 kPa and 50 kPa, respectively, followed by PU-CCTM2.5 at 130 kPa and 19 kPa and PU-CCUN2.5 at 100 kPa and 15 kPa. PU-CCTO treated by drying oven has the highest buoyancy force at 10% of PU-CCTO10 samples at 50%, followed by 45% of PUCCTM10 treated by microwave, and the lowest at 2.5 wt% of PU-CCUN2.5 untreated at 8%. In a nutshell, the prospective PU-CCTO is superior to the PU-CCUN and PU-CCTM related of the potential for overheating and burning the PU filler powder during the microwave processing procedure. In conclusion, the 10 wt% of PU filler treated by the drying oven method as a PU clay composite has the potential as an alternative material to improve the compressive strength, shear strength, and buoyancy force in soil improvement