Judul: Growth and Production of Indian Acalypha  (Acalypha indica) with different Inorganic Fertilizer Doses and Planting Media
Abstrak: Tumbuhan anting-anting (Acalypha indica) suku Euphorbiaceae merupakan salah satu jenis tumbuhan yang biasa digunakan sebagai obat karena senyawa biokimianya. A.indica mudah tumbuh dan sering dianggap sebagai gulma namun pengetahuan mengenai teknik budidaya masih terbatas. Penelitian ini bertujuan mempelajari pertumbuhan vegetatif dan mengetahui produktivitas A. indica dengan dosis pupuk anorganik dan media tanam yang berbeda. Penelitian dimulai dari bulan November hingga Desember 2023 di Gunung Batu, Bogor. Penelitian menggunakan metode rancangan kelompok lengkap teracak dua faktor. Faktor pertama yakni dosis pupuk NPK Mutiara (16-16-16) terdiri dari empat taraf, yaitu 0, 1, 2 dan 3 g/tanaman. Faktor kedua yakni media tanam terdiri dari tiga taraf, yaitu topsoil, topsoil + arang sekam (1:1 v/v) dan topsoil + pupuk kandang sapi (1:1 v/v). Hasil yang diperoleh menunjukkan penambahan dosis pupuk NPK 2 g/tanaman nyata meningkatkan bobot kering per tanaman. Media tanam topsoil + pupuk kandang sapi merupakan media tanam terbaik yang menghasilkan bobot kering per tanaman tertinggi. Penambahan dosis pupuk NPK 2 g/tanaman pada media tanam topsoil nyata meningkatkan bobot basah per tanaman. Penambahan dosis pupuk NPK 1 g/tanaman nyata meningkatkan bobot basah per tanaman. Media tanam topsoil + pupuk kandang sapi sudah memberikan pengaruh yang nyata dapat meningkatkan bobot basah tanpa penambahan pupuk NPK.
Keyword: Cultivation, NPK Fertilizer, cow manure

Judul: Peningkatan Pertumbuhan dan Hasil Tanaman Gedi (Abelmoschus manihot (L.) Medik.) dengan Aplikasi Pupuk Organik dan Pupuk Anorganik
Abstrak: The objective of this research was to study the effect of organic fertilizer and anorganic fertilizer rate to the growth and yield of gedi (Abelmoschus manihot (L.) Medik.). This research was conducted at Cikabayan Farm, Institut Pertanian Bogor, Indonesia from February to August 2011. The material plant was collected from Sorong, West Papua. The experiment was arranged in Completely Randomized Block Design with fertilizer rate as a single factor treatment. There were eight fertilizer rate treatments such as 0, 20, 40, 60 ton.ha−1 organic fertilizer and 0, 20, 40, 60 ton.ha−1 organic fertilizer + NPK. The organic fertilizer was used chicken manure and anorganic fertilizer NPK 15-15-15. The result of this research showed that using 30.39-34.04 ton.ha-1 of organic fertilizer rate will reached the optimum yield. The optimum rate of organic fertilizer + NPK fertilizer was not determined yet. But, by using of NPK fertilizer could increase the harvest.
Keyword: fertilizer dose, gedi, growth, production

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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