Judul: Induksi Embrio Somatik Kopi Robusta (Coffea canephora Piere ex Froehner) dengan Penambahan Auksin serta Sitokinin secara in Vitro.
Abstrak: Robusta coffee (Coffea canephora Piere ex Froehner) is an essential commodity in Indonesia. The objective of this research was to obtain the best media to induce somatic embryos of Robusta coffee for seedlings production. The explants were Robusta coffee (Coffea canephora Piere ex Froehner) variety BP 358 x BP 42 and induced by 2,4-D as auxin and BA or 2iP as cytokinins. Auxin and cytokinin as plant growth regulator and the interaction itself have no significant difference to induce callus from leaves explant. The highest persentage of callus from leaves explant is 86.7% in the medium with 5 μM 2,4-D and 20 μM BA. The interaction between 2,4-D as the auxin and BA or 2iP cytokinin has no significant difference to induce proembryo to become cotiledinary embryo. The highest persentage of proembryo was 81.04% in the medium with addition of 20 μM BA as cytokinin concentration. Embryo induction medium and also the interaction embryo induction medium with proembryo medium have no significant difference to induce proembryo become cotiledinary embryos. The effect of proembryo medium was significant difference the embryo growth at 19 week-after-treatment and also the embryo growth in 20 and 21 week-after-treatment. The highest persentage of proembryo become cotiledonary embryo is 33.3% in combination medium 0 mg l-1 2,4-D and in ½ MS medium with 4 mg l-1 BA. The highest persentage of germination is 82 % using 5 μM GA3. The highest number of embryo germination is 14.8 per 5 clumps in medium with 10 μM GA3 from proembryo which came from combination medium added with 1 μM 2,4-D dan 20 μM BA
Keyword: 

Judul: Embriogenesis somatik dan regenerasi tanaman pada kultur daun kopi robusta (Coffea canephora)
Abstrak: Tujuan penelitian ini terutama untuk rnempelajari penpembentukan kalus yang berasal dari daun tanaman kopi robusta ( Coffea canephora ), pernbentukan embrio somatik dan regenerasi tanaraan kopi dari kultur kalus. Hasil penelitian ini diharapkan dapat merupakan salah satu cara dalam upaya mempercepat penyediaan bibit dalam jurnlah besar untuk peremajaan dan perluasan areal tanaman kopi. Eahan tanaman yang digunakan adalah daun tanaQan kepi robusta klon BP 358. Kalus kopi dapat diinduksi bila potongan daun tanaman kopi ditumbuhkan pada medium basal Murashige dan Skoog ( 1962 ) yang mengandung 0. 25 mg/1 2.4D dan 1.00 mg/1 kinetin. Kalus tumbuh baik bila dipindahkan pada medium yang komposisinya sama kecuali konsentrasi garam anorganik diubah menjadi sepe rdua bagian. Dari berbagai konsentrasi zat pengatur tumbuh yang digunakan untuk in duksi embrio somatik, 0,25 mg/1 2.4D clan 0.50 mg/1 BA meru pakan kombinasi zat pengatur tumbuh yang terbaik. Kombina si zat pengatur tumbuh lain seperti 1. 00 mg/1 NAA dan 1. 00 mg/ 1 BA serta 1. 00 mg/ 1 NAA dan 4. 00 mg/ 1 BA menghasilkan embrio yang frekuensinya lebih rendah bila dibandingkan perlakuan diatas. Tanaman regenerasi dapat dibentuk bila embrio somatik yang berasal dari perlakuan 0.25 mg/1 2.4D dan 0.50 mg/1 BA dipindahkan ke medium cair tanpa BA sedang 2.4D diganti de ngan 5.00 mg/1 NAA,kemudian dipindahkan lagi ke medium agar yang T!lengandung 1.00 mg/1 NAA dan gula satu persen. Bila embrio somatik yang berasal dari perlakuan 1.00 mg/1 NAA dan 1.00 mg/1 BA serta 1.00 mg/1 NAA dan 4.00 mg/1 BA dipindahkan ke medium agar yang komposisinya sama tapi gula satu persen dan NAA 5. 00 mg/1 membentuk tanaman regenerasi dalam jumlah sedikit.
Keyword: Coffea canephora;, Regeneration, Somatic embryo genesis, Plant tissue culture

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: