Judul: Pengaruh naungan tegakan pohon terhadap pertumbuhan dan produktivitas beberapa tanaman sayuran indigenous
Abstrak: Percobaan ini dilakukan untuk mengetahui pengaruh naungan tegakan pohon terhadap pertumbuhan dan produktivitas beberapa tanaman sayuran indigenous. Percobaan dilaksanakan di Vegetable Garden, University Farm, Darmaga, Bogor mulai Februari 2009 hingga Juni 2009. Penelitian ini menggunakan Rancangan Acak Kelompok (RAK) faktor tunggal dengan 2 taraf naungan : naungan (N1) dan tanpa naungan (N0) dengan 4 ulangan masing-masing untuk 10 spesies tanaman sayuran indigenous sehingga kombinasi perlakuan menghasilkan 80 satuan percobaan pada luasan lahan 600 m2. Ukuran bedeng untuk setiap spesies tanaman sayuran indigenous adalah 5 m x 1.5 m dan jarak antar bedeng 60 cm. Bahan tanaman yang digunakan adalah 10 spesies tanaman sayuran indigenous: Kenikir (Cosmos caudatus), Kemangi (Ocimum americanum), Beluntas (Pluchea indica), Pohpohan (Pilea trinervia), Daun Ginseng (Talinum triangulare), Kedondong Cina (Nothopanax fruticosum), Mangkokan (Nothopanax scutellarium), Terubuk (Saccharum edule), Sambung Nyawa (Gynura procumbens), Katuk (Sauropus androgynus). Benih kenikir dan kemangi disemai pada tray semai selama 3 minggu. Bahan tanaman lainnya diperbanyak dengan cara stek batang. Jarak tanam yang digunakan untuk tanaman beluntas, kenikir, kemangi, poh pohan, terubuk, dan mangkokan adalah 50 cm x 25 cm; jarak tanam untuk tanaman katuk, daun ginseng, sambung nyawa, dan kedondong cina adalah 50 cm x 20 cm.
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Judul: Pengaruh Jarak Tanam Terhadap Produksi Tiga Sayuran Indigenous
Abstrak: The purpose this research was to determine the effect of plant spacing (population) on growth and yield of some indigenous vegetables (kemangi, kenikir, and katuk). The research was conducted at Cikabayan experiment garden in Darmaga, Bogor from April until November 2010. The experiment design was a Randomized Complete Design Group one factor with four treatments plant spacing of population [P1] 25 cm × 13:33 cm (population 300 000 plants/ha), [P2] 25 cm × 16 cm (population 250 000 plants/ha), [P3] 25 cm × 20 cm (population 200 000 plants/ha), and [P4] 25 cm × 26.67 cm (population 150 000 plants/ha), with three replications. Observations included plant height, number of leaves, number of branches, weight yields/plant and weight yield/plot. The result of the experiment showed that plant spacing of kemangi did not influence vegetative growth, weight yields/plant and weight yield/plot. Plant spacing of kenikir influenced number of leaves, number of branches, weigth yields/plant and proned influence weight yield/plot on plan spacing 25 cm × 13:33 cm (population 300 000 plants/ha). Plant spacing of katuk did not influence vegetative growth, weight yields/plant and weight yield/plot.
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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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