Judul: Karakterisasi Berbagai Aksesi Meniran (Phyllanthus niruri L.), Studi Perkecambahan dan Pematahan Dormansi
Abstrak: Penelitian ini dilakukan untuk mengkarakterisasi beberapa aksesi meniran, mendapatkan informasi dan mempelajari sifat perkecambahan dan metode uji viabilitas pada benih meniran. Penelitian ini dilaksanakan pada bulan Februari 2012 sampai Juni 2012. Penelitian dilaksanakan di Kebun Percobaan Sawah Baru dan Laboratorium Ilmu dan Teknologi Benih IPB, Bogor. Bahan yang digunakan dalam penelitian ini meliputi benih dari aksesi Gresik, aksesi Jember, dan empat aksesi asal Bogor yang terdiri atas aksesi Kebon Kalapa, aksesi Leuwikopo, aksesi Sawah Baru, aksesi Semplak, dst
Keyword: Bogor Agricultural University, Institut Pertanian Bogor, IPB, Phyllanthus niruri L., Aksesi, Pra perkecambahan, Metode pengecambahan

Judul: Karakterisasi Berbagai Aksesi Meniran (Phyllanthus niruri L.), Studi Perkecambahan dan Pematahan Dormansi.
Abstrak: This research aims to characterize some accession meniran, get information about seed viability of meniran and methods germination test of meniran. This research was conducted from February 2012 to June 2012. The accession of Phyllanthus niruri L. that used in this research are come from Gresik, Jember, Kebon Kalapa, Leuwikopo and accession come from Semplak. The research consists of three experiments. The first experiment to characterize meniran. Experimental design used is a Randomized Blok Design (RKLT) by a factor that is accession. A second experiment to see the effect of pre-germination on the viability meniran. The data obtained were tested by t test. The third experiment get information about methods of germination test meniran. The data obtained were tested by t test. The results of the research showed that characters of Phyllanthus niruri L is devided in to three main grouped, where the degree of similarity 45.21% Jember accession separately from the other accessions. Differences accession Jember prominent than the other accessions in character fruit color (red), branch color (red-purple), while the other accessions green. At the rate of 77.63% similarity, there are Gresik and Semplak in one group and Kebon Kalapa, Leuwikopo, Sawah Baru in other group that has highest production of biomass. Seed soaking treatment with water and 250 ppm IAA gives the same effect as no treatment on the viability various accession meniran. Value germination pre soaking seed treatment with GA3 influence was significantly higher when compared with the value of germination without treatment, seed treatment with 250 ppm GA3 increase seed viability meniran, increased viability seen from the increase to grow the seed, grow the seed in which the value of 49.7% (without treatment) increased to 79.0% (GA3 soaking treatment). Meniran seed germination in the nursery with soil mixed media manure with a ratio of 1:1 has has the higher average value of the maximum growth when compared with germination in laboratory test methods. In this research, the test method in the form of laboratory test methods and UDK ½ UKDdp with or without pre-germination of GA3 250 ppm, not to be able to represent the corresponding germination potential of the seeds germinated in the nursery.
Keyword: 

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: