Judul: Pertumbuhan dan Produksi Kacang Bogor (Vigna subterranea (L.) Verdcourt) dengan Pelbagai Dosis dan Cara Pemberian Pupuk Kandang Ayam
Abstrak: This research aimed to get optimal rate of manure and proper manure application to increase crop production of bambara groundnut. The research was conducted from February to June 2014 at IPB experimental field. The experiment used factorial in randomized complete block design with two factors and three replications. The first factor was rates of chicken manure with four i.e. 0, 5, 10, and 15 tons ha-1. The second factor was 2 application methods of manure i.e. spread over the soil surface and put in planting row. Growth and production of bambara groundnut was insignificantly affected by neither manure rates nor manure applicaton methods. Although there was not significant effect of manure rates, there was indication that the highest yield (number of pods per plant) of bambara groundnut could be achieved with the addition of 6.8 tons manure ha-1. Bambara groundnut crop were heavily infected by desease at 7 weeks after planting, this might have resulted in insignificant effect of treatments to all variables.
Keyword: crop substitution, chicken manure, legume

Judul: Pertumbuhan dan Produksi Kacang Bogor (Vigna subterranea (L.) Verdcourt) pada Beberapa Jarak Tanam dan Frekuensi Pembumbunan
Abstrak: This research aimed to get optimal plant spacing and proper frequency in ridging to produce the best yields. This research was conducted in randomized complete block design factorial with two factors and three replications. The first factor is plant spacing which consist of six levels: 40 cm x 25 cm, 50 cm x 25 cm, 60 cm x 25 cm, 40 cm x 40 cm, 50 cm x 50 cm, and 60 cm x 60 cm. The second factor is ridging frequencies which consist of two levels: twice and three times ridging. The result of this research showed that plant spacing effected significantly the number of leaves, canopy width, leaf area index, plant dry weight per plant, pods wet weight per plant, pods dry weight per plant, seed weight per plant, number of filled pods per plant, number of harvested plant, pods wet weight plot, pods dry weight plot, and seed weight plot, whereas ridging frequency only effected significantly on plant dry weight per plant. Plant spacing 60 cm x 25 cm and 40 cm x 40 cm produced the best yields and suitable for use in plant cultivation.
Keyword: ridging, plant spacing, bambara groundnut

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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