Judul: Pengaruh Taraf Kombinasi Rumput Gajah dan Limbah Tauge sebagai Alternatif Sumber Serat terhadap Kualitas Fisik Pellet Kelinci Selama Penyimpanan.
Abstrak: Sprouts waste (SW) is an alternative materials which potentially replace elephant grass (EG) as a source of fiber on feed. This study aims to test the physical quality of pellets for rabbit which contains SW and EG as a source of fiber with different storage periods. This study was arranged in a Completely Randomized Design Factorial (4x4), contains factor A: sprouts waste levels (P0 = 15% EG + 85% concentrate, P1 = 10% EG + 5% SW + 85% concentrate, P2 = 5% EG + 10% SW + 85% concentrate, and P3 = 15% SW + 85% concentrate), and factor B: storage periods (0, 2, 4, 6 weeks). Data were analyzed with analysis of variance (ANOVA) and followed by Duncan test. The results indicated that the combination level of SW and EG very significantly increased the particle size, durability, and also decreased the bulk density and compacted bulk density (P<0.01). P2 showed the best physical quality because it had a high particle size, required medium storage space with the highest durability and decreased feed price. The storage periods very significantly decreased the physical quality of pellets (P<0.01). In this study, there was an interaction between treatments on spesific density and bulk density
Keyword: Bogor Agricultural University (IPB), storage, sprouts waste, physical quality

Judul: Substitusi Rumput Gajah dengan Limbah Tauge dalam Ransum Bentuk Pellet terhadap Performa dan Nilai Komersil Kelinci Jantan Lokal persilangan.
Abstrak: Alternative feed rations to reduce the use of commercial waste are sprouts. This study aimed to compare the performance of local male rabbits fed by complete sprouts waste pellet shaped to substitute the use of elephant grass. This study used a completely randomized design with 4 treatments and 4 repetitions. There were 16 local male rabbits aged 2 months with an average live weight 879.375 + 60.874 g head-1. Treatments consisted of P0 = 15 % of elephant grass + 85 % of concentrate, P1 = 10 % elephant grass + 5 % of sprouts waste + 85 % concentrate, P2 = 5 % of elephant grass + 10 % sprouts waste + 85 % concentrate, P3 = 15 % of sprouts waste + 85 % concentrate. Data were analyzed by analysis of variance (ANOVA). The results showed that the use of waste to the extended 15 % of sprouts waste pellets could substitute the usage of elephant grass and reduce the price of feed to give a good performance on the local male rabbits. Daily weight gain of rabbits given pellet P2 and P3 is 18.954 to 19.785 g day-1 with a final body weight greater than P0 and P1. The highest pellet consumption is the treatment of P2 and P1, the consumption of P3 pellet treatment is not too high and shows the average final body weight better than others. It also could decrease the cost.
Keyword: sprouts waste., performance, Pennisetum purpureum, pellets, local male rabbits

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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