Judul: Correlation Analysis of Environmental Factors on Kudzu (Pueraria javanica) Growth and Productivity
Abstrak: Kondisi lingkungan merupakan masalah utama dalam menghasilkan hijauan yang berkualitas, di antaranya intensitas cahaya, curah hujan, suhu, dan kelembapan. Penelitian ini bertujuan untuk menganalisis hubungan antara pertumbuhan dan produktivitas tanaman kudzu (Pueraria javanica) dengan faktor lingkungan. Penelitian ini menggunakan metode penelitian lapang dengan data iklim dari BMKG Bogor. Hasil penelitian menunjukkan tinggi tanaman, jumlah daun, dan jumlah cabang berkorelasi positif kuat dengan curah hujan. Intensitas cahaya, kelembapan, dan suhu memiliki nilai korelasi yang rendah dengan variabel pertumbuhan tanaman. Produktivitas kudzu terbesar pada lima bulan dengan berat segar sebesar 10,56 ton ha-1 tahun-1 dan berat kering sebesar 2,5 ton ha-1 tahun-1., Environmental conditions are the main problem in producing quality forage, including light intensity, rainfall, temperature, and humidity. This study aims to analyze the relationship between the growth and productivity of kudzu (Pueraria javanica) plants with environmental factors. This study used a direct field research method with climate data from BMKG Bogor. The result showed that plant height, number of leaves, and number of branches had a strong positive correlation with rainfall. Light intensity, humidity, dan temperature had a low correlation value with plant growth variables. Kudzu has the highest productivity at five months with a fresh weight of 10,56 tons ha-1 years-1 and a dry weight of 2,5 tons ha-1 years-1.
Keyword: climate, correlation analyze, growth, kudzu, productivity

Judul: Pengaruh Pengapuran, P, dan K terhadap Pertumbuhan dan Produksi Kedelai Hitam pada Budi Daya Jenuh Air di Lahan Pasang Surut
Abstrak: This research was conducted to study the effect of lime ameliorant, P and K fertilizer on the growth and productivity of black soybean under saturated soil culture on tidal swamps, in Banyu Urip Village, Tanjung Lago Sub District, Banyuasin District, South Sumatera Province on May-August 2014. This experiment used Block Randomized Design, three factor with three replication. First factor is ameliorant of lime, consisted of 4 levels, i.e: 0, 1 000, 2 000 dan 3 000 kg ha-1 dolomit. Second factor is P fertilizer, consisted of 2 levels, i.e: 36 and 72 kg ha-1 P2O5 . Third factor is K fertilizer, consisted of 2 levels, i.e: 30 and 60 kg ha-1 K2O. This research result showed that the interaction P and K fertilizer influenced on the plant height, leave number, branch number, nodule dry weight, and productivity. The interaction P and lime influenced on the leave number on 8 Week After Planting. The interaction K and lime influenced on the branch number. The highest productivity was obtained on 3000 kg ha-1 dolomit (4.063 ton ha-1 ).
Keyword: Bogor Agricultural University (IPB), marginal land, saturated soil culture, ameliorant and fertilizer

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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