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: Preference of Sutterranean Termites to Several Species of Community Wood from Bogor, West Java
Abstrak: Perlu upaya diversifikasi kayu tusam sebagai kayu umpan. Selain itu lama waktu pengumpanan menjadi pertimbangan dalam melakukan pengumpanan. Penelitian ini bertujuan untuk mengevaluasi preferensi rayap tanah terhadap beberapa jenis kayu rakyat dari Bogor dan mengetahui lama waktu terbaik dalam pengumpanan. Kayu yang diuji yaitu Acacia mangium, Paracerianthes falcataria, Anthocephalus cadamba, Maesopsis eminii, Swietenia mahagoni, Hevea brasiliensis, Pinus merkusii. Uji lapang dilakukan berdasarkan American Society for Testing and Material D 1758-06 di Arboretum, Fakultas Kehutanan dan Lingkungan IPB dengan waktu pengumpanan satu sampai enam bulan. Hasil penelitian menunjukkan bahwa, frekuensi serangan rayap pada tapak pengujian sebesar 93,1%. Rata-rata kehilangan berat tertinggi yaitu karet (65,8%) dan terendah yaitu mahoni (7,1%). Semua jenis kayu yang diuji, kecuali mahoni, berpotensi menjadi alternatif umpan rayap. Jenis rayap yang ditemukan adalah Microtermes sp,. Macrotermes sp., Shedorhinotermes sp., dan Capritermes sp., Pine wood requires diversification as bait wood. Also, baiting period is an important consideration for the baiting process. The objectives of this research were to study the termites preference towards several types of community wood from Bogor and to know the best baiting period in baiting process. Wood that has been tested were Acacia mangium, Paracerianthes falcataria, Anthocephalus cadamba, Maesopsis eminii, Swietenia mahagoni, Hevea brasiliensis, and Pinus merkusii. The field tests were carried out according to American Society for Testing and Material D 1758-06 at the Arboretum of Faculty of Forestry and Environment of IPB University with baiting period of one to six month. The results showed that the frequency of termite attacks was 93,1%. The highest average of the weight loss was rubber (65,8%) and the lowest was mahogany (7,1%). All types of wood that have been tested, except mahogany, have the potential to be an alternative for the termite bait. The type of termites found was Macrotermes sp, Microtermes sp., Shedorhinotermes sp., and Capritermes sp.
Keyword: Attack frequency, weight loss, damage intensity, bait period, termite bait

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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