Tensile Strength Properties of Tropical Hardwoods in Structural Size Testing
In Malaysia, there is no research done on the tensile strength of structural size timber. The tension stress found in the Malaysian code of practice, MS 544: Part 2: 2001, was not determined directly and it was taken as 60% of the bending strength values of small clear specimens. This paper presents the results of the tensile test on structural size timber specimens from selected Malaysian Tropical hardwoods namely Kedondong (Canarium spp), Keruing (Dipterocarpus spp) and Bintangor (Calophyllum spp) under the strength group SG5. A special tensile grip was fabricated using the model suggested in ASTM D198 and the tests were also conducted according to ASTM D198. The tensile strength characteristics evaluated include tensile strength, modulus of elasticity and Poisson’s ratio, and the data were analyzed statistically. In this study it was found that the grade stresses for structural size specimens were higher than that published in the Malaysian code of practice. Index Term— tensile strength, structural size, Malaysian
RELATIONSHIP BETWEEN MECHANICAL PROPERTIES OF STRUCTURAL SIZE AND SMALL CLEAR SPECIMENS OF TIMBER
penandaan Eropah untuk kayu struktur memerlukan ujian beberapa ciri mekanik dalam saiz struktur. Bagaimanapun, keperluan ini masih belum dilaksanakan untuk kebanyakan spesies kayu tropika, termasuklah kayu Malaysia. Data kekuatan kayu Malaysia yang sedia ada adalah berdasarkan ujian mekanik spesimen bersaiz kecil tanpa kecacatan. Ujian awalan dijalankan ke atas beberapa kayu komersial terpilih untuk mengkaji hubungan antara kekuatan kayu bersaiz struktur dengan kayu kecil tanpa kecacatan. Ujian lenturan terhadap pelbagai spesies kayu keras dijalankan ke atas spesimen bersaiz struktur dan bersaiz kecil tanpa kecacatan. Hubungan yang lemah diperhatikan antara kekuatan lentur spesimen bersaiz kecil tanpa kecacatan dengan spesimen bersaiz struktur. Hubungan modulus kekenyalan adalah konsisten walaupun untuk spesimen yang belum dikeringkan dan belum digred.
Design and assembly of ternary Pt/Re/SnO2 NPs by controlling the zeta potential of individual Pt, Re, and SnO2 NPs
AbstractIn this study Pt, Re, and SnO2 nanoparticles (NPs) were combined in a controlled manner into binary and ternary combinations for a possible application for ethanol oxidation. For this purpose, zeta potentials as a function of the pH of the individual NPs solutions were measured. In order to successfully combine the NPs into Pt/SnO2 and Re/SnO2 NPs, the solutions were mixed together at a pH guaranteeing opposite zeta potentials of the metal and oxide NPs. The individually synthesized NPs and their binary/ternary combinations were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning transmission electron microscopy (STEM) combined with energy dispersive X-ray spectroscopy (EDS) analysis. FTIR and XPS spectroscopy showed that the individually synthesized Pt and Re NPs are metallic and the Sn component was oxidized to SnO2. STEM showed that all NPs are well crystallized and the sizes of the Pt, Re, and SnO2 NPs were 2.2, 1.0, and 3.4 nm, respectively. Moreover, EDS analysis confirmed the successful formation of binary Pt/SnO2 and Re/SnO2 NP, as well as ternary Pt/Re/SnO2 NP combinations. This study shows that by controlling the zeta potential of individual metal and oxide NPs, it is possible to assemble them into binary and ternary combinations.
 Graphical abstractᅟ