Judul: Pengaruh Umur Pohon Tetua dan Jumlah Buku Stek Cabang terhadap Pertumbuhan Bibit Jarak Pagar (Jatropha curcas L.).
Abstrak: The research was conducted in February-July 2010 in the greenhouse and in the seed science and technology laboratory of agronomy and horticulture department, leuwikopo, Bogor Agriculture University,. The aim of this research to know the effect of mother plant age, internode numbers of stem cutting, and interaction on growth of seedling-stem cutting of Jatropha curcas Linn. Research method applied Randomize Complete Block Design with two factors, namely mother plant age (U) (U1=2 year, U2=3 year, and U3=4 year) and internode numbers (B) (B1= 10 internode, B2= 15 internode, and B3= 20 internode) with three replicates. The result showed that there are effects of mother plant age, internode numbers, and their interaction on growth of seedling-stem cutting of Jatropha curcas Linn. The mother plant age for the best sprout length, leaf length, and leaf width are 4 year and 2 year. The best internode numbers for the best sprout number are the 20 and 15 internode. Interaction between mother plant age and the best internode numbers according to the plant height parameter is mother plant age 4 year with 20 internode.
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Judul: Pengaruh pemangkasan dan pemupukan terhadap pertumbuhan dan hasil tanaman jarak pagar [Jatropha curcas L.]
Abstrak: Penelitian ini bertujuan untuk mengetahui pengaruh pemangkasan dan pemupukan, serta interaksinya terhadap pertumbuhan dan hasil tanaman jarak pagar (Jatropha curcas L.). Penelitian dilaksanakan di Kebun Percobaan Cikabayan, Darmaga IPB dan berlangsung selama enam bulan, yaitu dari bulan November 2008 sampai dengan Mei 2009. Penelitian ini menggunakan rancangan faktorial dalam Rancangan Acak Kelompok (RAK). Perlakuan terdiri atas dua faktor yaitu tingkat pemangkasan cabang primer dan tingkat pemupukan Urea, SP-36 dan KCl. Tingkat pemangkasan cabang primer terdiri dari 3 taraf yaitu, pemangkasan dengan memelihara dua cabang primer (P1), pemangkasan dengan memelihara tiga cabang primer (P2), dan pemangkasan tanpa pembatasan jumlah cabang primer yang dipelihara (P3). Tingkat pemupukan terdiri dari tiga taraf dosis pemupukan yaitu tanpa pupuk (N0), kombinasi pemupukan 40 g urea, 40 g SP-36 dan 40 g KCl per tanaman (N1), kombinasi pemupukan 80 g urea, 80 g SP-36 dan 80 g KCl per tanaman (N2). Tiap perlakuan diulang tiga kali sehingga terdapat 27 satuan percobaan.
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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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