Judul: Pengaruh Dosis Pupuk Kandang dan Arang Sekam Terhadap Pertumbuhan Tanaman Garut (Maranta arundinacea L.) Di Bawah Naungan Tegakan Sengon [Paraserianthes falcataria (L.) Nielsen]
Abstrak: Garut (Maranta arundinacea L.) was proposed by government as one of food comodities which take priority to be developed and cultivated because it potential as a wheat flour substitute, which is containing alternative sources of carbohydrate. Garut not only used for food, but also for industrial raw materials. Therefor, research about growth of garut plant with different manure doses under shade of P. falcataria stands has been done with the measured parameters are high stems, plant height, diameter, and number of leaves of garut. The design of this experiment using Completely Random Design (CRD) with two factorials. Doses of manure used are 0 gram, 200 gram, 400 gram and 600 gram, and also with the addition of charcoal husk with a 1:1 ratio with the soil. From the results indicate that interaction between manure doses and charcoal husk didn’t give real effect for high stem, diameter, and number of leaves of garut plant, and only gives real impact for plant height. On the parameter number of leaves, although the interaction between manure doses and charcoal husk doesn’t give real effect, but manure doses gives real effect for the number of leaves. Duncan test result showed that 600 gram dose of manure gave a significantly different effect for the number of garut leaves.
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Judul: Pengaruh lama penaungan dan dosis pupuk nitrogen terhadap pertumbuhan dan produksi rimpang garut (Maranta arundinaceae L.)
Abstrak: Percobaan ini dilakukan untuk mengetahui pengaruh lama penaungan dan beberapa taraf dosis pupuk nitrogen (urea) terhadap pertumbuhan dan produksi rimpang garut. Percobaan dilaksanakan di kebun percobaan IPB Sindang Barang, laboratorium terpadu PSPT, dan laboratorium BALITBIO dari bulan Maret sampai November 2000. Bahan tanaman yang digunakan berupa bibit garut yang berasal dari rimpang yang telah disemaikan selama 45 hari. Paranet digunakan untuk membuat naungan dengan intensitas cahaya matahari masuk 45 %. Pupuk urea digunakan sesuai perlakuan dan diaplikasikan 2 kali, yaitu saat tanam dan pada saat tanaman berumur 12 MST. Percobaan ini menggunakan rancangan perlakuan petak terbagi dalam rancangan lingkungan acak kelompok. Perlakuan petak utama adalah lama penaungan dengan 3 lama penaungan, yaitu penaungan sampai tanaman berumur 16 MST, 24 MST, dan 32 MST. Dosis pupuk urea merupakan perlakuan anak petak dengan 3 taraf dosis, yaitu: 100 kg, 200 kg, dan 300 kg per ha. Tiap kombinasi perlakuan diulang 3 kali. Peubah persentase bibit yang hidup diamati pada umur 1 MST. Peubah yang diamati mulai umur 2 MST sampai 31 MST meliputi peubah tinggi tanaman dan jumlah anakan/rumpun. Peubah ILD, panjang dan diameter rimpang, bobot basah dan kering rimpang, bobot basah dan kering tajuk/rumpun, bobot basah dan kering akar/rumpun diamati setiap kali panen yaitu pada umur 16 MST, 24 MST, dan 32 MST. Intensitas cahaya di dalam dan di luar naungan diukur pada minggu ke 10, 20 dan 30 setelah tanam. Kandungan klorofil daun dan pati rimpang serta tepung garut dianalisis pada panen ke tiga (umur 32 MST). Hasil percobaan menunjukkan bahwa penaungan sampai umur 32 MST nyata menghasilkan jumlah anakan, bobot basah dan kering tajuk serta akar terkecil. Penaungan yang panjang (sampai umur 32 MST) cenderung menurunkan ..dst
Keyword: rimpang garut, pemupukan, dosis pupuk, ekologi, nitrogen

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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