Judul: Pengaruh Pemupukan Kalium terhadap Pertumbuhan dan Produksi Beberapa Varietas Kedelai Hitam (Glycine soja) pada Budidaya Jenuh Air di Lahan Pasang Surut
Abstrak: Saturated soil culture can prevent oxidation of pyrite from negative influences and it can to improve the productivity of soybean. The objective of this experiment was to study the effect of potassium fertilization on the growth and production of Ceneng, Cikuray, Lokal Malang, and Tanggamus under saturated soil culture on tidal swamp. The experiment was conducted at Banyu Urip, Tanjung Lago, Banyuasin, West Sumatera, from May until September 2013. The experiment used split plot design with 3 replications. The main plot was is variety consisted of Ceneng, Cikuray, Lokal Malang, and Tanggamus. The sub plot was is potassium fertilization consisted of 0, 30, 60 and 90 kg K2O ha-1. The experiment results show that kalium fertilization increased yield of black soybean. Productivity was affected by single factors that is variety and potassium fertilization. The interaction between variety and potassium fertilization did not effect to the all variables. The highest productivity of black soybean was obtained from Ceneng variety, 3.58 ton ha-1. The potasium fertilization 90 kg ha-1 gave the highest productivity as such as 3.72 ton ha
Keyword: saturated soil culture, potassium, Lokal Malang, Cikuray, Ceneng

Judul: Pengaruh Pemupukan Fosfor terhadap Pertumbuhan dan Produksi Beberapa Varietas Kedelai Hitam (Glycine Soja) pad a Budidaya Jenuh Air di Lahan Pasang Surut
Abstrak: Saturated soil culture is a cultivation that gives continuous irrigation and maintains water depth constantly and makes soil layer in saturated condition. Technology of saturated soil culture has been shown to increase soybean production on tidal swamps. The objective of this experiment to study the effect of phosphorus fertilization on the growth and production variety of soybean under saturated soil culture on tidal swamps. The experiment was conducted at Banyu Urip, Tanjung Lago, Banyuasin, South Sumatera, Indonesia from May to September 2013. The experiment used a split plot design with three replications. The main plot of the experiment is black soybean variety consisted of : Ceneng, Cikuray, Lokal Malang and Tanggamus as control . Sub plot is the dosage of phosphorus fertilization consisted of : 0, 36, 72 and 108 kg P2O5 ha-1. The results showed that the variety and phosphorus fertilization affected soybean productivity. The highest productivity was obtained on Cikuray variety with phosphorus fertilization 108 kg P2O5 ha-1 as much as 4.03 ton ha-1.
Keyword: Tidal Swamp, Saturated Soil Culture, Phosphorus Fertilization, Black Soybean Variety

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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