Judul: Keragaan Planlet Dendrobium Lasianthera (Jj. Smith) Hasil Iradiasi Sinar Gamma Generasi Mv1
Abstrak: Dendrobium merupakan salah satu genus anggrek yang paling banyak diminati oleh konsumen. Dendrobium lebih disukai karena bentuk dan warna bunganya lebih bervariasi, daya tahan kesegaran bunganya lebih lama, produktivitasnya tinggi dan harganya terjangkau. Salah satu anggrek dendrobium spesies yang ada di Indonesia dan dipergunakan dalam penelitian ini adalah Dendrobium lasianthera (JJ. Smith) yang berasal dari Papua Nugini dengan ciri khasnya berpetal keriting. Penelitian ini bertujuan untuk mengidentifikasi keragaman karakter kuantitatif dan keragaan planlet Dendrobium lasianthera (JJ. Smith) setelah aklimatisasi yang sebelumnya telah diiradiasi sinar gamma pada kondisi in vitro dengan dosis 0, 20, 40, 60 dan 80 Gy. Hasil dari penelitian ini menunjukkan bahwa iradiasi sinar gamma dapat menginduksi keragaman dan berpengaruh nyata terhadap karakter kuantitatif yaitu jumlah daun, panjang daun, lebar daun, tinggi tanaman, jumlah akar, panjang akar, ukuran stomata, kerapatan stomata dan pengurangan jumlah kromosom. Pada keragaan tanaman juga terdapat perubahan berupa bentuk daun, bentuk ujung daun, tekstur permukaan daun, simetri daun dan tanaman roset.
Keyword: anggrek, keragaman, kromosom, karakter kuantitatif, stomata

Judul: Pengaruh iradiasi sinar gamma terhadap pertumbuhan plb anggrek Dendrobium lasianthera (JJ. Smith) secara in vitro
Abstrak: This research aimed to learn the effect of gamma ray-irradiation on protocorm like bodies (plb) Dendrobium lasianthera and determined Lethal dosage (LD) 30 and 50. The irradiation has done at the Center of Technology Application of Isotops and Radiation, Nuclear Energy Agency (PATIR-BATAN), the research started from February 2014 to July 2014. The research implemented the completely randomized design (CRD) with a single factor that gamma rayirradiation dosage were 0 Gy, 20 Gy, 40 Gy, 60 Gy, 80 Gy, and 100 Gy. Each dose of gamma ray-irradiation treatment was repeated 5 times, of which there were 30 units of the experiment and each experimental unit consisted of five culture bottles were individually planted 4 plb Dendrobium lasianthera. The results of this research showed that the effect of gamma ray-irradiation dose significantly decreased the percentage of live plb, percentage of plb germination, number of leaves, number of roots, the percentage of rooted plant. Plantlets changes observed among other wide leaves, and the spiral leaves. Lethal dose 30% (LD30) was at 19.7697 Gy irradiation dose and LD50 was at 67.3504 Gy irradiation dose.
Keyword: Bogor Agricultural University (IPB), mutation, Lethal Dosage (LD), in vitro, gamma ray-irradiation, Dendrobium lasianthera

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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