Judul: Optimasi Pupuk Kalium dan Magnesium pada Tanaman Kelapa Sawit (Elaeis guineensis Jacq.) Belum Menghasilkan Umur Tiga Tahun.
Abstrak: Aplikasi pupuk dengan dosis yang tepat sangat penting dilakukan pada tanaman kelapa sawit. Tujuan penelitian ini adalah untuk mempelajari respons morfologi, fisiologi, dan produksi serta menentukan dosis optimum pupuk K dan Mg pada tanaman kelapa sawit TBM 3. Penelitian dilaksanakan di Kebun Pendidikan dan Penelitian Kelapa Sawit Jonggol IPB-Cargill, Kecamatan Jonggol, Kabupaten Bogor dari bulan September 2015 sampai Maret 2016. Penelitian terdiri atas dua percobaan terpisah dengan menggunakan satu faktor Rancangan Kelompok Lengkap Teracak (RKLT). Percobaan optimasi pupuk K (percobaan 1) terdiri atas 5 taraf (0, 225, 450, 675, dan 900 g K2O tanaman-1 semester-1) dengan 3 ulangan, sedangkan percobaan optimasi pupuk Mg (percobaan 2) terdiri atas 4 taraf (0, 62,5, 125, dan 250 g MgO tanaman-1 semester-1) dengan 3 ulangan. Perlakuan pupuk kalium meningkatkan pertumbuhan tanaman secara kuadratik terhadap panjang pelepah ke-17. Dosis optimum pupuk kalium adalah 594 g K2O tanaman-1 semester-1. Perlakuan pupuk magnesium tidak memberikan pengaruh nyata terhadap peubah morfologi, fisiologi, dan produksi tanaman kelapa sawit TBM 3.
Keyword: fisiologi, morfologi, pelepah, respons, taraf

Judul: Optimasi Pupuk Magnesium pada Tanaman Kelapa Sawit (Elaeis guineensis) Belum Menghasilkan Umur Dua Tahun.
Abstrak: The aims of this research were to study growth response of immature oil palm age of two years and to determine optimum rate of magnesium fertilizer. This experiment was conducted at the IPB-Cargill Palm Oil Teaching Farm, Jonggol, Bogor from March 2014 to February 2015. The experimental design used in this research was a randomized complete block design with 3 replications. Kieserite fertilizer consist of four levels i.e. without Kieserite (control), 625, 1250, 2500 g of Kieserite fertilizer year-1. The result of this research showed that Kieserite had not affected on height of oil palm, diameter of stem, number of leaflet, length of leaflet, leaf area, and physiological parameters.
Keyword: magnesium, oil palm, optimizing fertilizer, response

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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