Judul: Efek Populasi Cacing Eisenia foetida Savigny, Kapur dan Pupuk NPK terhadap Aspek Kualitas Nutrisi dan Produktivitas Centrosema pubescens Benth pada Latosol Dramaga.
Abstrak: Feed is one of important role on a farm, exspecially for livestock because its help animal to grow and make good performance. This research aimed to determine and to compare the effect of E. foetida population, lime and NPK fertilizer levels for nutrient quality and productivity of C. pubescens on Latosol Dramaga soil. The design of the experiment was Complete Randomized Design (CRD) with factorial pattern (2 x 2 x 3) and three replications. Factor 1 was level of NPK, factor 2 was level of lime and factor 3 was level of E. foetida population. The data were analyzed by using SAS version 9.0. The results showed that it was not significant on productivity (P>0.05) but it was significant on nutrient quality (P<0.05). C. pubescens had highest crude protein affected by lime, NPK factor and interaction between three factors. Calsium was significantly affected by lime, E. foetida population and interaction between three factors.
Keyword: nutrient quality and productivity, NPK fertilizer, lime, E. foetida population, latosol, C. pubescens

Judul: Pengaruh pemberian Cacing Tanah Eisenia foetida pada Tanah Latosol dan Podsolik Merah Kuning terhadap Kualitas dan Produktivitas Centrosema pubescens Benth.
Abstrak: Eisenia foetida merupakan salah satu jenis cacing tanah yang biasa digunakan sebagai pupuk vermikompos yang dapat memperbaiki kualitas lahan hijauan pakan. Tujuan penelitian ini adalah untuk mengidentifikasi efek E. foetida pada jenis tanah yang berbeda terhadap produktivitas dan kualitas Centrosema pubescens Benth. Penelitian ini menggunakan rancangan acak lengkap (RAL) dengan pola faktorial 2 x 2 dengan level pemberian cacing (0 dan 60 cacing tanah) dan jenis tanah (Latosol dan Podsolik Merah Kuning) dengan 3 kali ulangan dan dilakukan selama 60 hari dengan pemanenan setiap 20 hari. Hasil Analisis interaksi antara cacing dan jenis tanah tidak berpengaruh nyata (P> 0.05) terhadap laju pertumbuhan tanaman, laju pertumbuhan daun, biomassa dan NPK C. pubescens. Level pemberian cacing tanah E. foetida berpengaruh nyata (P <0.05) terhadap biomasa C. pubescens pada umur 40 Hari Setelah Tanam (HST). Sedangkan perlakuan jenis tanah memberikan pengaruh signifikan (P <0.05) terhadap kandungan P C. pubecens.
Keyword: Centrosema pubescens, Eisenia foetida, Latosol, Podsolik Merah Kuning

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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