Judul: Pengaruh Dosis Ekstrak Rebung Bambu Betung (Dendrocalamus asper Backer ex Heyne) Terhadap Pertumbuhan Semai Sengon (Paraserianthes falcataria (L.) Nielsen).
Abstrak: Berbagai usaha untuk mempercepat pertumbuhan bibit banyak dilakukan antara lain dengan menggunakan pupuk atau zat pengatur tumbuh (ZPT). Sampai dengan saat ini penggunaan ZPT sebagai upaya meningkatkan kualitas pertumbuhan, baik ZPT alami maupun buatan (sintesis) masih menjadi kebutuhan penting dalam perlakuan terhadap tanaman. Rebung merupakan bambu muda dan salah satu hasil hutan non kayu yang pada awal pertumbuhannya berbentuk kerucut, kokoh dan terbungkus dalam kelopak daun yang rapat disertai bulu-bulu halus.
Keyword: 

Judul: Pengaruh Dosis Ekstrak Rebung Bambu Betung (Dendrocalamus asper Backer ex Heyne) Terhadap Pertumbuhan Semai Sengon (Paraserianthes falcataria (L.) Nielsen)
Abstrak: Some efforts to accelerate seedling growth have been done by using fertilizer or growth regulator substances (GRS). Until now, natural or synthetic GRS is still being important substance in plant treatment. Bamboo shoot is young bamboo and as one of non-timber forest products; which is at the beginning growth having conical form, strong and wrapped by dense leaves ornamented with fine hairs. Betung bamboo is presumed containing GRS due to its fast growth, particularly, at young phase. In 100 gram betung bamboo shoot contains water 91 g; protein 2.6 g; carbohydrate 5.20 g; fat 0.90 g; fibers 1.0 g; vitamin A 20 SI; potassium 533 mg; phosphor 53 mg; dust 0.90 mg; and also others minerals such as riboflavin; niacin; thiamin; calcium and iron in small quantity (Watt and Merril, 1975). Bamboo shoot is suspected containing hormone GA3 which may increase internodes growth. Therefore, it is necessary to observe the effect of doses of Betung bamboo shoots extract to the growth sengon seedlings at green house conditions. Research was carried out in green house at Sylviculture laboratory SEAMEO BIOTROP, Tajur, Bogor, West Java. Observation was carried out for four months, started from June until September 2008. The materials used were latosol sub-soil from Bogor, betung bamboo shoot was obtained from Sukasari Bogor and extracted at Sylviculture Laboratory, sands, and sengon seed were obtained from Forest Tree Seed Bureau (BPTH) Bogor. The Experimental design was in completely randomized design (CRD) with six dose treatments those were A0 (control); A1 (10 ml/seedling); A2 (20 ml/seedling); A3 (30 ml/seedling); A4 (40 ml/seedling); and A5 (50 ml/seedling). Number of replicate was three times with 10 seedlings for each replicate, therefore there were 180 sengon seedlings. The observation result showed that all dose treatments could increase the sengon seedling growth, while there was no effect to the amount of root nodules. It was presumed that the extract of bamboo shoot made soil reaction (pH) getting more acid so that the root nodule was difficult to develop. Improvement in sengon seedling growth was influenced by potassium and thiamin contain in betung bamboo shoot extract. Seedlings’ quality in the treatment A5 (50 ml/seedling) was the highest with scoring point 88. While the lowest was obtained in A0 (control) with total point scoring was 19. The scoring value of the treatments at 10 ml/seedling (A1), 20 ml/seedling (A2), 30 ml/seedling (A3), and 40 ml/seedling was 51, 75, 69 and 47 respectively. Variation in growth response to the extract to at bamboo shoot was due to (1) Different sources of bamboo shoot production areas, (2) Different active compound, (3) Different genetic variation, and (4) Different harvesting season. Based on this observation, we may conclude that the effective dose of betung bamboo shoot extract to increase sengon seedling growth was 20 ml/seedling to 50 ml/seedling.
Keyword: 

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.
Keyword: