Judul: Pengaruh Perbedaan Jarak Tanam Terhadap Pertumbuhan, Produksi dan Kualitas Indigofera zollingeriana.
Abstrak: Indigofera zollingeriana adalah legum yang tinggi kandungan protein serta menghasilkan produksi yang stabil dalam berbagai macam kondisi cuaca. Tujuan penelitian ini adalah untuk mengetahui efek dari perbedaan jarak tanam terhadap laju pertumbuhan, produksi hijauan dan kualitas. Penelitian ini menggunakan Rancangan Acak Kelompok dengan empat perlakuan. Setiap perlakuan jarak tanam sebagai berikut: 1m×1.5m; 1m×1m; 1m×0.75m; 1m×0.5m sehingga memiliki kepadatan tanaman yang berbeda, yaitu 12, 15, 20, 30 plot-1. Data dianalisis menggunakan analisis ragam. Perbedaan yang signifikan diantara perlakuan di uji lanjut menggunakan uji Duncan dan Polinomial Orthogonal. Hasil menunjukkan peningkatan tinggi tanaman pada jarak tanam 1m×0.5m. Peningkatan terjadi sejalan dengan kepadatan tanaman hingga 30 tanaman. Peningkatan populasi tanaman tidak berpengaruh nyata terhadap tinggi tanaman, jumlah cabang dan daun. Peningkatan populasi tanaman hingga 30 tanaman meningkatkan kan pula produksi hijauan sampai 10 888 gram dan bahan kering sampai 32.74%. Peningkatan populasi tidak berpengaruh nyata terhadap kandungan NDF, ADF, PK dan β-caroten.
Keyword: Indigofera zollingeriana, jarak tanam, kualitas, pertumbuhan, produksi hijauan

Judul: Growth Characteristics of Indigofera zollingeriana at Different Land Altitude in Conservation Areas.
Abstrak: Penelitian ini bertujuan mengevaluasi tingkat adaptasi pertumbuhan hijauan pakan Indigofera zollingeriana yang ditanam di kawasan konservasi pada ketinggian lahan berbeda. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) terdiri dari 3 perlakuan berdasarkan ketinggian lahan 900 mdpl (P1), 1000 mdpl (P2) dan 1300 mdpl (P3) dengan 5 ulangan. Peubah yang diamati yaitu intensitas cahaya, suhu, kelembaban, tinggi tanaman, diameter batang, jumlah cabang, jumlah daun dan jumlah tunas. Data dianalisis menggunakan ANOVA dan perlakuan berbeda nyata diuji lebih lanjut dengan uji Duncan menggunakan program SPSS versi 25. Analisis regresi dilakukan untuk mengukur pengaruh ketinggian lahan penanaman dengan tinggi tanaman Indigofera zollingeriana. Perbedaan ketinggian lahan penanaman Indigofera zollingeriana berpengaruh sangat signifikan (P<0,01) terhadap tinggi tanaman, diameter batang, jumlah cabang, jumlah daun dan jumlah tunas. Hasil analisis regresi memiliki kecenderungan negatif yaitu dengan nilai R2 = 0,6334, ketinggian lahan penanaman berpengaruh negatif terhadap tinggi tanaman Indigofera zollingeriana., This study aimed to evaluate the adaptation level of Indigofera zollingeriana forage growth planted in conservation areas at different altitudes. The study employed a Completely Randomized Design (CRD) consisting of 3 treatments based on different altitudes: 900 meters above sea level (P1), 1000 meters above sea level (P2), and 1300 meters above sea level (P3), each with 5 replications. The variables observed were light intensity, temperature, humidity, plant height, stem diameter, number of branches, number of leaves, and number of shoots. Data were analyzed using ANOVA, and significant treatment differences were further tested using Duncan's test with SPSS version 25. Regression analysis was performed to measure the influence of planting altitude on the height of Indigofera zollingeriana plants. The different planting altitudes of Indigofera zollingeriana significantly influenced (P<0.01) the height of the plants, stem diameter, number of branches, number of leaves, and number of shoots. The regression analysis showed a negative trend with an R2 value of 0.6334, indicating that planting altitude had a negative effect on the height of Indigofera zollingeriana plants.
Keyword: conservation area, Indigofera zollingeriana, morphological characteristics, land elevation

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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