Judul: Pertumbuhan dan produksi daun Torbangun (Plectranthus amboinicus Spreng.) dengan pemupukan organik dan pemangkasan
Abstrak: Tanaman torbangun berkhasiat untuk memperlancar air susu ibu (ASI) karena mengandung laktagogen. Penelitian mengenai tanaman torbangun lebih banyak di bidang farmakologinya saja, oleh sebab itu perlu adanya penelitian di bidang teknik budi daya dengan menggunakan pupuk organik dan pemangkasan. Tujuan penelitian ini adalah untuk mendapatkan pengaruh pupuk organik dan pemangkasan terhadap pertumbuhan dan produksi daun torbangun. Rancangan penelitian ini menggunakan rancangan acak kelompok (RAK) pada siklus 1 dengan faktor pemupukan, dan rancangan perlakuan Split plot pada siklus 2 dengan pemupukan sebagai petak utama dan pemangkasan sebagai anak petak. Rataan hasil pada masing-masing siklus diuji lanjut menggunakan uji beda nyata jujur (BNJ). Pemupukan organik terbagi menjadi 5 taraf; tanpa pemupukan, pupuk kandang sapi+fosfat alam, pupuk kandang sapi+abu sekam padi, fosfat alam+abu sekam padi, dan pupuk kandang sapi+fosfat alam+abu sekam padi. Pemangkasan terbagi menjadi 2 taraf; tanpa dipangkas dan dipangkas. Hasil penelitian ini menunjukkan bahwa pemupukan yang menggunakan pupuk kandang sapi+fosfat alam+abu sekam padi dapat meningkatkan bobot basah pucuk 125.21% dibandingkan dengan perlakuan tanpa pemupukan. Pemangkasan menurunkan biomasa tanaman dan jumlah daun. Pertumbuhan tanaman torbangun termasuk lambat, sehingga pemanenan harus dilakukan pada umur tanaman yang lebih lama.
Keyword: Bogor Agricultural University, Institut Pertanian Bogor, IPB

Judul: Pengaruh Pupuk dan Interval Defoliasi terhadap Pertumbuhan dan Produksi Tanaman Torbangun (Coleus amboinicus Lour)
Abstrak: This research was conducted to measure the growth and the production of torbangun. The factors are defoliation rate and organic fertilizer . Defoliation was treated in two levels : once per 6 weeks (D1) and once per 9 weeks (D2). Fertilizer treatments were 100% broiler manure fertilizer (PK 3), 75% broiler manure fertilizer with PSB (Phosphate Solubilizing Bacteria) & AMF (Arbuscula Mycorrhizal Fungi) (PK 2), and 50% broiler manure fertilizer with PSB & AMF (PK 1). Each treatment was replicated for 6 times in 18 weeks. The first defoliation was conducted three times while the second defoliation was conducted twice. The measured variables are leaves amount, canopy height, leaf width, fresh weight of leaves, dried weight of leaves. The results showed that the interaction between PK 3 and D1 had the best effect in the increase of leaves amount. PK 3 and PK 2, individually, gave a good impact to the increase of canopy height. The other results showed that PK 2 gave the best impact to dried leaves weight (p<0.05)
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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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