Judul: Pengaruh penyadapan dan posisi tandan terhadap mutu benih serta teknik konservasi kecambah terhadap pertumbuhan bibit aren (Arenga pinnata (Wurmb) Merr).
Abstrak: The experiment was conducted at Seed Science and Techology Laboratory of IPB, from January to October 2012. The aim of this research was to investigate if tapping of male inflorescence and position of female inflorescence affect seed quality (experiment 1) and conservation technique and period at seedling stage affect subsequent growth of sugar palm seedling (experiment 2). A completely Randomized Design with two factors was used in experiment 1. The first factor was tapping i.e untapped and tapped. The second factor was position of female inflorescence i.e first, third and fifth. Each experiment was replicated four times. Split plot design with two factors was used in the experiment 2. The main plot was conservation technique i.e. plastic bag, rice husk charcoal with 10%, 20% and 30% moisture content, saw mill husk with 10%, 20% and 30% moisture content.The sub plot was periode of conservation i.e without conservation, one week and two weeks conservation. The result of experiment 1 showed that tapping and position of female inflorescence did not affect seed quality therefore seed can be taken from any trees in all position of female inflorescence. The result of experiment 2 showed that rice husk charcoal with 20% and 30% moisture content was effective for conservation sugar palm seedling up to two weeks.
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Judul: Effect of Addition of Several Combinations of Growth Regulatory Substances (PGR) and Pre-Treatment Media on In Vitro Growth of Sugar Palm (Arenga pinnata Merr) Zygotic Embryos.
Abstrak: Aren (Arenga pinnata Merr) merupakan famili Arecaceae yang tumbuh soliter. Tanaman ini memiliki tandan yang ditumbuhi oleh buah aren. Buah aren memiliki embrio yang dapat digunakan sebagai bahan perbanyakan secara generatif. Perbanyakan bibit aren melalui embrio diharapkan dapat menghasilkan bibit secara cepat dan berkualitas. Tujuan penelitian ini untuk melakukan evaluasi pengaruh pemberian kombinasi ZPT dan media pra perlakuan pada tanaman aren secara in vitro dalam petumbuhan dan perkembangan membentuk tunas. Hasil penelitian menunjukkan bahwa pemberiaan kombinasi ZPT dan penggunaan media pra perlakuan secara masing-masing berpengaruh dalam pertumbuhan embrio aren. Pemberian kombinasi terbaik dengan BAP 7,5 ppm + IAA 2 ppm menunjukkan pengaruh yang nyata terhadap kontrol dalam pertumbuhan kecambah embrio aren hingga membentuk tunas dan media tanpa pra perlakuan menunjukkan hasil terbaik dalam pertumbuhan embrio menjadi tunas. Pemberian ZPT dan pengunaan media pra perlakuan berpengaruh dalam pertumbuhan embrio aren., Aren (Arenga pinnata Merr) is a solitary growing family of Arecaceae. This plant has bunches overgrown with palm fruit. Palm fruit has an embryo that can be used as a generative propagation material. Propagation of palm seeds through embryos is expected to produce seeds quickly and with quality. The purpose of this study was to evaluate the effect of giving a combination of PGR and pre-treatment media on sugar palm plants in vitro on growth and development to form shoots. The results showed that the combination of PGR and the use of pre-treatment media each had an effect on the growth of sugar palm embryos. Giving the best combination with BAP 7.5 ppm + IAA 2 ppm showed a significant effect on control in the growth of sugar palm embryo sprouts to form shoots and media without pretreatment showed the best results in embryo growth into shoots. The administration of PGR and the use of pre-treatment media had an effect on the growth of sugar palm embryos.
Keyword: Embryo, in vitro, pre-treatment, sugar palm

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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