Judul: Characteristics of cross laminated timber made from fast growing species with a different number of layers
Abstrak: Cross laminated timber (CLT) is one of the engineered wood products made by arranging a number of layers of wood crossing one another, which are then glued with adhesive. The purpose of this study was to determine the effect of timber spesies and number of layers to physical and mechanical properties of CLT, to investigate the number of layers and wood species of CLT constituent that produce the best characteristics and compare the physical and mechanical properties of CLT with solid wood. The wood species used in this study were mangium wood (Acacia mangium Willd.), afrika (Maesopsis eminii Engl.) and jabon (Anthocephalus cadamba Miq.). CLT beam was divided into 3 groups based on the number of lamina layers, 3 layers, 5 layers and 7 layers respectively. The adhesive used was Water Based Polymer Isocyanate (WBPI), applied on both surfaces to be bonded with the spreading weight of 280 g/m2. The test method of physical and mechanical properties of CLT was conducted based on ASTM D143-05 : Standard Test Methods for Small Clear Specimen of Wood. The study results showed that the type of wood and the number of layers significantly influenced the physical and mechanical properties of CLT. In comparison of the physical and mechanical properties of CLT with solid wood, the average density and stiffness of CLT were equivalent to those of its solid wood, the average value of moisture content in CLT was 2.3 to 5.6% lower compared to that of solid wood, the average value of bending strength for CLT with 5 layers was equivalent to that of its solid wood while the CLT of 3 and 7 layers was 18.3 to 18.6% lower compared to its solid wood, the average value of compressive strength parallel to grain of CLT was 21.8 to 26.1% lower than that of its solid wood, and the average value of shearing strength for afrika and jabon CLT was equivalent to its solid wood whereas that of mangium CLT was 26.8 to 47.4% lower when compared to its solid wood Key words : Cross laminated timber, fast growing species, physical and mechanical properties. . The layers number of CLT that produce the best characteristics is the 5 layers and the wood species that produces the best characteristics is mangium wood.
Keyword: 

Judul: Karakteristik Cross Laminated Timber Kayu Jabon berdasarkan Ketebalan dan Orientasi Sudut Lamina
Abstrak: Along with the technological developments, a new method of laminated timber has been found, called by cross laminated timber (CLT). CLT is an engineered product of wood composed of some lamina or layers bonded in an arrangement of layers crossing one another. The purpose of this research was to design a panel of CLT by modifying the combined patterns of different thickness and orientation angles of lamina in order to have the highest strength values and determine the characteristics of CLT panels as structural timber. The study results are expected to provide alternative benefits or uses of wood from the community forests as a product of CLT, give information to the people about the quality of CLT panel from the community forest and increase the chance of timber development from the community forests for structural wood products. The thickness of lamina applied in the manufacture of CLT panels were 1.0, 1.67, 2.0 and 3.0 cm with the width of 15 cm and the length of 120 cm. CLT panel was formed of three layers or lamina with the cross-sectional size of 5 cm x 15 cm x 120 cm based on the value of its MOE with three types of combination in lamina thickness, namely type A1 (1 cm, 3 cm, and 1 cm), type A2 (1 cm, 2 cm, and 1 cm), and type A3 (1.67 cm, 1.67 cm, and 1.67 cm). The middle layer was based on the orientation angles of lamina: 0°, 30°, 45°, 60°, and 90°. The adhesive used was water based polymer isocyanate (WBPI) with the glue spreading of 280 g/m2 for both surfaces. Testing was based on ASTM D 143 (2005) and JAS 234:2003 standard. The result showed that the combined thickness of lamina had a significant effect on the mechanical properties of MOE, MOR and compressive strength parallel to fibers on CLT panels. The lamina orientation angles had a significant effect on the physical properties of volume shrinkage and expansion on CLT panels. On the other hand, as for the mechanical properties, the angle orientation of lamina showed a significant effect on MOE, MOR, compressive strength parallel to fibers, and the bonding strength of CLT panels. The interaction between a combined thickness of lamina and angle orientation only significantly influenced the compressive strength parallel to fibers of CLT panels. Meanwhile, based on the scoring of CLT panel, the combined thickness of lamina type A3 and the angle orientation of 30o had the best properties. This is because the number of connections on the angle orientation of 30o Key words: Cross laminated timber, jabon wood, physical and mechanical properties, less than those of other angle orientations. The resulted analysis of the whole or intact timber (control) showed that in general CLT panels have better properties of volume shrinkage and expansion than the intact original timber.
Keyword: 

Judul: Infeksin virus rota pada anak babi
Abstrak: Virus Rota sudah lama diduga sebagai salah satu penyebab diare pada anak babi yang baru dilahirkan. Hal ini diperkuat dengan berhasilnya Mebus dan kawan-kawan mengidentifikasi virus Rota pada kejadian diare yang ter jadi pada anak sapi yang baru dilahirkan. Infeksi virus Rota merupakan hal yang serius, kejadian yang mewabah pernah dilaporkan di Amerika Serikat, Inggris, Kanada dan Australia. Sedangkan kejadian di Indonesia yang dihubungkan dengan infeksi virus Rota belum dilaporkan. Virus Rota termasuk keluarga Reo viridea. Sesuai dengan namanya, virus Rota menyerupai roda (Rota = Wheel), mengandung asam nukleat (nucleid acid) yang berupa asam nukleat ribo (ribo nucleid acid, RNA) dan berserabut ganda (double stranded), tidak mempunyai selubung (envelop atau peplos). Hewan rentan adalah hewan yang berumur sangat muda. Selain menyerang babi, dapat pula menyerang sapi, domba, rusa, anjing, kucing, tikus, kelinci, unggas dan manusia. ...
Keyword: