Judul: Pengaruh Tingkat Kemasakan Benih Duabanga moluccana BI terhadap  Perilaku Perkecambahan dan Pertumbuhannya pada Media Tanah, Kompos dan Arang Sekam Padi di Persemaian
Abstrak: Kebutuhan ekonomi mendorong berkembangnya teknologi industri perkayuan, sehingga berpengaruh terhadap penyediaan bahan baku. Untuk memenuhi kebutuhan tersebut maka Departemen Kehutanan merencanakan untuk membangun Hutan Tanaman Industri (HTI) dalam skala besar yaitu ditargetkan 4.6 juta ha sampai dengan tahun 2000, sehingga bahan baku dapat tersedia cukup dan berkesinambungan. Salah satu syarat untuk mengembangkan HTI adalah karakteristik tanaman yang digunakan harus sesuai, yaitu jenis cepat tumbuh, riap tinggi dan rotasi pendek.
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Judul: Penggunaan Kompos Sampah Pasar dan Arang Sekam terhadap Pertumbuhan Bibit Cabutan Duabanga moluccana Blume
Abstrak: Duabanga moluccana merupakan jenis pionir cepat tumbuh dan memiliki prospek untuk dikembangkan dalam hutan tanaman. Namun terdapat permasalahan dalam perbanyakannya dengan benih, seperti kecambah mudah terserang penyakit lodoh dan pertumbuhan kecambah yang sangat lama. Pengadaan bibit masih banyak menggunakan topsoil sebagai media tumbuh yang dikhawatirkan merusak lingkungan karena jumlahnya terbatas, untuk itu perlu dicari solusi dengan menggunakan subsoil yang diperkaya dengan nutrisi dari bahan organik. Penelitian ini bertujuan mengetahui pengaruh penggunaan kompos sampah pasar dan arang sekam terhadap kualitas bibit cabutan D. moluccana. Bibit D. moluccana ditanam dalam empat perlakuan media tumbuh, yaitu subsoil (P0), subsoil : kompos (4:1, v/v) (P1), subsoil : kompos : arang sekam (3:1:1, v/v/v) (P2), subsoil : kompos : arang sekam (2:1:2, v/v/v) (P3). Hasil penelitian selama tiga bulan menunjukkan bahwa media dengan penambahan kompos dan arang sekam mampu meningkatkan kualitas bibit D. moluccana asal cabutan alam dengan baik. Media P2 menghasilkan bibit dengan pertumbuhan terbaik, yaitu tinggi (26.60 cm), diameter (4.60 mm), berat kering total (18.80 g), dan memiliki nilai indeks mutu bibit terbaik (30 poin)., Duabanga moluccana is a fast-growing pioneer species and has the prospect of being developed in plantation forests. However, there are some problems in propagation by seeds, such as susceptible to dumping off and the germinates grow slowly. Seedling productions are still using topsoil as a growing media which is feared to damage the environment due to its limited number. Therefore, it is necessary to use the subsoils enriched with nutrients from organic materials. This study aims to determine the effect of market waste compost and rice husk charcoal on the quality of D. moluccana wildings. D. moluccana seedlings were planted in four growing media treatments, namely subsoil (P0), subsoil : compost (4:1, v/v) (P1), subsoil : compost : rice husk charcoal (3:1:1, v/v/v) (P2), subsoil : compost : rice husk charcoal (2:1:2, v/v/v) (P3). The results of the three-month study showed that the media with the addition of compost and husk charcoal was able to improve the quality of D. moluccana seedlings. P2 media produced the best seedling growth on height (26.60 cm), diameter (4.60 mm), total dry weight (18.80 grams), and had the best seedling quality index value (30 points).
Keyword: growing media, organic matter, seedlings, subsoil

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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