Judul: Keragaan Galur-galur Harapan Sorgum (Sorghum bicolor (L.) Moench) di Tanah Masam, Jasinga
Abstrak: This research was aimed to obtain information on performance of sorghum IPB breeding lines under acid soil conditions. The research was conducted at Cikopomayak, Jasinga, Bogor from March to August 2013. The experimental design used was Randomized Complete Block Design with genotype as the treatment. The plant materials used were 17 strain of sorghum IPB breeding lines, Numbu and UPCA S1 as check varieties. The results showed that there were significantly different among genotypes evaluated for leaf number, flowering time, panicle length and thousand of grain weight. Leaf number, plant height, diameter of stem positively correlated with biomass weight. Plant height, diameter of stem, biomass weight and thousand of grain weight positively correlated with grain weight panicle-1. The IPB breeding lines showed comparable grain weight panicle-1 to the check varieties. Yield potential of N/UP-4-3, N/UP-82-3, N/UP-118-7, N/UP-124-7, N/UP-139-1 dan N/UP-139-5 strain were better than UPCA S1 in range 3–4 ton ha-1.
Keyword: sorghum, performance, genotipe, acid soil

Judul: Keragaan Galur-galur Harapan Sorgum (Sorghum bicolor (L.) Moench) di Tanah Masam, Jasinga
Abstrak: Penelitian ini dilaksanakan dengan tujuan untuk mendapatkan informasi tentang keragaan galur-galur harapan sorgum hasil pemuliaan IPB di tanah masam. Penelitian ini dilaksanakan di Desa Cikopomayak, Kecamatan Jasinga, Kabupaten Bogor mulai bulan Maret sampai Agustus 2013. Rancangan percobaan yang digunakan adalah Rancangan Kelompok Lengkap Teracak (RKLT) dengan satu faktor (genotipe). Genotipe yang digunakan adalah 17 galur hasil pemuliaan IPB dan 2 varietas pembanding yaitu Numbu dan UPCA S1. Berdasarkan hasil analisis ragam diketahui bahwa terdapat perbedaaan keragaan galur-galur sorgum yang diuji untuk karakter jumlah daun, umur berbunga, panjang malai, dan bobot 1000 butir. Karakter jumlah daun, tinggi tanaman dan diameter batang berkorelasi positif dan nyata terhadap bobot biomassa. Karakter tinggi tanaman, diameter batang, bobot biomassa dan bobot 1000 butir berkorelasi positif dan nyata terhadap bobot biji per malai. Galur-galur yang diuji memiliki bobot biji per malai setara dengan kedua pembanding. Galur harapan sorgum yang memiliki potensi hasil lebih baik dari varietas UPCA S1 dengan kisaran antara 3–4 ton ha-1 adalah N/UP-4-3, N/UP-82-3, N/UP-118-7, N/UP-124-7, N/UP-139-1 dan N/UP-139-5.
Keyword: genotipe, acid soil, performance, sorghum

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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