Judul: Pengaruh Dosis Pupuk Kandang dan Arang Sekam Terhadap Pertumbuhan Tanaman Garut (Maranta arundinacea L.) Di Bawah Naungan Tegakan Sengon [Paraserianthes falcataria (L.) Nielsen]
Abstrak: Garut (Maranta arundinacea L.) was proposed by government as one of food comodities which take priority to be developed and cultivated because it potential as a wheat flour substitute, which is containing alternative sources of carbohydrate. Garut not only used for food, but also for industrial raw materials. Therefor, research about growth of garut plant with different manure doses under shade of P. falcataria stands has been done with the measured parameters are high stems, plant height, diameter, and number of leaves of garut. The design of this experiment using Completely Random Design (CRD) with two factorials. Doses of manure used are 0 gram, 200 gram, 400 gram and 600 gram, and also with the addition of charcoal husk with a 1:1 ratio with the soil. From the results indicate that interaction between manure doses and charcoal husk didn’t give real effect for high stem, diameter, and number of leaves of garut plant, and only gives real impact for plant height. On the parameter number of leaves, although the interaction between manure doses and charcoal husk doesn’t give real effect, but manure doses gives real effect for the number of leaves. Duncan test result showed that 600 gram dose of manure gave a significantly different effect for the number of garut leaves.
Keyword: 

Judul: Pengaruh Bahan Tanam dan Waktu Pemupukan Pupuk Kandang terhadap Pertumbuhan Garut (Maranta arundinaceae L.)
Abstrak: Tanaman garut (Maranta arundinaceae L.) merupakan tanaman umbi-umbian yang digolongkan dalam famili Marantaceae dan dikelompokkan pada umbi-umbian minor. Peningkatan produktivitas garut dapat dilakukan melalui pemupukan dan penggunaan bahan tanam. Penelitian ini bertujuan mempelajari pengaruh bahan tanam dan pemberian pupuk kandang sapi, serta interaksinya terhadap pertumbuhan dan produktivitas tanaman garut. Penelitian dilaksanakan di Kebun Percobaan Cikabayan IPB, Dramaga, Bogor dari bulan Februari hingga Agustus 2019. Percobaan pertama menggunakan Rancangan Kelompok Lengkap Teracak (RKLT) dengan faktor tunggal, pengaruh bahan tanam. Bahan tanam bagian tengah umbi menghasilkan rataan jumlah stek bertunas dan jumlah tunas per stek tertinggi. Percobaan kedua menggunakan Rancangan Split Plot dengan petak utama waktu pemupukan dan anak petak perlakuan bahan tanam. Perlakuan waktu pemupukan tidak mempengaruhi peubah yang diamati. Perlakuan bagian umbi sebagai bahan tanam memberikan pengaruh pada tinggi anakan, dan jumlah anakan saat 12 dan 20 MST, kehijauan daun tanaman induk dan anakan serta bobot kering brangkasan, bobot segar brangkasan tanaman garut.
Keyword: produktivitas, sumber karbohidrat, pupuk kandang, bibit

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.
Keyword: