Judul: Potensi Hijauan Pakan di Bawah Naungan Indigofera zollingeriana Miq. dengan Status Umur Tanaman Berbeda
Abstrak: Penelitian ini bertujuan mengukur potensi hijauan pakan di bawah naungan tanaman Indigofera zollingeriana dengan status umur berbeda di Unit Pendidikan Penelitian Peternakan Jonggol. Metode yang digunakan adalah observasi langsung di lapang Data dianalisis menggunakan analisis deskriptif. Parameter yang diukur adalah karakteristik tanah, kelembaban, suhu, intensitas cahaya, tingkat naungan, komposisi botani, kapasitas tampung, analisis vegetasi, identifikasi hijauan, produksi biomassa, kualitas fisik silase, serta palatabilitas silase. Hasil penelitian menunjukkan terdapat 16 spesies dari 3 lahan indigofera yang berbeda umur dan berpotensi menjadi hijauan pakan. Simpulan dari penelitian adalah perbedaan umur vegetasi sangat mempengaruhi jenis tumbuhan dan spesies yang tumbuh dibawah naungan dan intensitas cahaya pada lahan tersebut. Tanaman yang berpotensi menjadi pakan ialah Sphagneticola trilobata (L.) Pruski. yang mendominasi lahan Indigofera 7 tahun karena sifat tanaman yang membutuhkan cahaya dan kandungan nitrogen yang tinggi., This study evaluated the potential for forage production under Indigofera zollingeriana plants of varying ages at the Unit Pendidikan Penelitian Peternakan Jonggol (UP3J). The method employed involved directly observing the forage growth under the Indigofera gardens. The data collected were analyzed using descriptive analysis, with parameters such as soil characteristics, humidity, temperature, light intensity, shade level, botanical composition, storage capacity, vegetation analysis, forage identification, biomass production, silage physical quality, and silage palatability taken into consideration. The study revealed that 16 species of plants across three Indigofera fields of different ages had potential for forage production. The research concluded that the age of vegetation significantly affects the types of plants and species that grow under shade and the light intensity on the land. Sphagneticola trilobata (L.) Pruski was identified as one of the plants with the potential to become a food source, and it dominates the year 7 Indigofera land due to its need for light and high nitrogen content.
Keyword: analisis vegetasi, Indigofera zollingeriana, rumbah, umur vegetasi

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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