Judul: Subterranean Termite Attack on Tree Stands in Bogor Botanical Garden
Abstrak: Pelestarian dan perlindungan terhadap pohon-pohon yang tersimpan di Kebun Raya Bogor (KRB) perlu dilakukan untuk menghindari kerusakan oleh berbagai macam penyakit maupun serangga perusak termasuk rayap. Penelitian bertujuan menganalisis frekuensi serangan rayap dan mengidentifikasi jenis rayapnya, menganalisis preferensi rayap terhadap jenis pohon, serta tingkat kerusakan pohon akibat serangan rayap di KRB. Penelitian dilakukan dengan menggunakan metode jalur sampling. Hasil penelitian menunjukkan bahwa sebanyak 213 (100%) pohon contoh di KRB terserang rayap. Spesies rayap tanah yang ditemukan sekurang-kurangnya terdapat empat spesies yaitu Coptotermes curvignathus Holmgren, Macrotermes gilvus Hagen, Odontotermes javanicus Holmgren dan Nasutitermes matangensis Haviland. Rayap M. gilvus banyak ditemukan pada pohon Pterocarpus indicus, Dysoxilum spp., Shorea spp., dan Dimocarpus spp.. Rayap O. javanicus banyak ditemukan pada pohon Vitex cofassus, Dehaasia incrassata, Heriteria spp., dan Cordia spp.. Rayap N. matangensis banyak ditemukan pada pohon Philodendrom spp., Dysoxilum spp., dan Sindora spp.. Rayap C. curvignathus banyak ditemukan pada pohon Araucaria columnaris, Agathis sp., dan Pinus spp. Tingkat kerusakan pohon contoh akibat serangan rayap sebesar 10-90%., Preservation and protection of trees stored in the Bogor Botanical Gardens (KRB) need to be done to prevent damage by various kinds of diseases and destructive insects including termites. This study aimed to analyze the frequency of termite attacks and to identify the type of termites, to analyze termite preferences for tree species, as well as the degree of tree damage due to termite attacks in KRB. The research was conducted using the path sampling method. The results showed that as many as 213 (100%) sample trees in KRB were attacked by termites. There are at least four subterranean termite species found, namely Coptotermes curvignathus Holmgren, Macrotermes gilvus Hagen, Odontotermes javanicus Holmgren, and Nasutitermes matangensis Haviland. Termites M. gilvus are found in Pterocarpus indicus, Dysoxilum spp., Shorea spp., and Dimocarpus spp. Termites O. javanicus are found in Vitex colossus, Dehaasia incrassate, Heriteria spp., and Cordia spp. Termites N. matangensis is found in Philodendrom spp., Dysoxilum spp., and Sindora spp. Termites C. curvignathus can be found in Araucaria columnaris, Agathis sp., and Pinus spp. The level of damage to sample trees due to termite attacks is 10-90%.
Keyword: frequency, subterranean termites, termite preferences, tree healt

Judul: Wood Decomposers in Six Community Wood Species at Two Locations
Abstrak: Kayu memiliki hubungan erat dengan rayap dan jamur sebagai dekomposer. Penelitian ini bertujuan menganalisis jumlah kayu terserang rayap dan jamur pada enam jenis kayu rakyat selama enam bulan pengujian pada dua lokasi berbeda, menganalisis tingkat kerusakannya, serta mengidentifikasi spesies rayap dan jamur yang menyerangnya. Penelitian dilakukan pada dua lokasi, yaitu Arboretum Fakultas Kehutanan dan Lingkunan IPB serta permukiman di Bogor Asri, Kecamatan Cibinong, Kabupaten Bogor. Kayu yang diuji adalah Acacia mangium, Falcataria moluccana, Anthocephalus cadamba, Maesopsis eminii, Pinus merkusii, dan Hevea brasiliensis. Pengujian dilakukan berdasarkan ASTM D 1758-06. Jumlah kayu terserang meningkat seiring dengan lama waktu pengujian dan serangannya di arboretum (75%) lebih tinggi dibanding di permukiman (39,4%). Tingkat kerusakan kayu tertinggi di arboretum adalah kayu karet (35,4 g) sedangkan di permukiman adalah kayu pinus (18,9 g). Jenis rayap tanah yang ditemukan adalah Macrotermes sp., Microtermes sp., Schedorhinotermes sp., dan Odontotermes sp. Jenis jamur pelapuk yang ditemukan adalah Aspergillus sp., Mucor sp., Trichoderma sp., Gliocladium sp., Mycelia sterilia, dan cendawan merah., Wood has a close relationship with termites and fungi as decomposers. This study aims to analyze the frequency of termite and fungal attacks on six community wood species during six months testing period at two different locations, to analyze the intensity of wood damage, and to identify the species of termites and fungi that attack them. The research was conducted at two locations, namely the Arboretum of the Faculty of Forestry and Environment of IPB and the settlement area in Bogor Asri, Cibinong District, Bogor Regency. The woods tested were Acacia mangium, Falcataria moluccana, Anthocephalus cadamba, Maesopsis eminii, Pinus merkusii, and Hevea brasiliensis. The tests were carried out according to ASTM D 1758-06. The frequency of attacks increased with the length of time of testing and the attacks were higher in arboretum (75%) than in settlement (39,4%). The highest intensity of wood damage in the arboretum was rubber wood (35,4 g); in settlements, it was pine wood (18,9 g). The subterranean termites found were Macrotermes sp., Microtermes sp., Schedorhinotermes sp., and Odontotermes sp. The rot fungi found were Aspergillus sp., Mucor sp., Trichoderma sp., Gliocladium sp., Mycelia sterilia, and red fungi.
Keyword: arboretum, rot fungus, settlement, subterranean termites

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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