Judul: Fenologi Pembungaan Pinang Yaki (Areca vestiaria Giseke) di Kebun Raya Bogor
Abstrak: One of the palm genus that available widely in Indonesia is Areca. Areca vestiaria is a palm species endemic in Sulawesi which has an unique characteristics and important components in a tropical rainforest. A. vestiaria has many functions, such as, materials for handicrafts, medicinal herb of diabetes, and for male tonic. Based on the benefits, people will continue to use it. Uncontrolled utilization will lead it to extinction. Hence, need of conservation to preserve it. For this reason, it is necessary assess aspects of flowering phenology of A. vestiaria. Samples consist of lowland and upland Sulawesi accessions. Parameter of flower phenology consist of period of development flowering time, at each development phase, and the micro-climate factors. Flowering of A. vestiaria includes of initiation, bud towards anthesis, anthesis, and young fruit until maturity. The result showed that in each phase has a different time. Overall, the flowering development was not directly affected by a particular micro-climate factors. The insects visitors dominant were Trigona sp. and windspeed was caused high persentage of pollination.
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Judul: Keragaman Genetik Aksesi Pinang (Areca catechu L.) Asal Papua, Sulawesi Utara, dan Sumatera Utara Berdasarkan Karakter Morfologi dan Penanda RAPD (Random Amplified Polymorphic DNA)
Abstrak: Areca nuts (Areca catechu L.) is a palm plant that has not been studied intesively than other palm crops (coconut). Areca nuts is used as ingredients of medicines, cosmetics, and ceremonial, as well as a symbol of social and cultural relationship. The objectives of these studies were to explore genetic diversity of areca nuts accessions (Areca catechu L.) from Papua, North Sulawesi and North Sumatera that were collected and planted in Experimental Station Kaiwatu, Indonesian Coconut and Palmae Research Institute (Balitka), Manado. These studies were conducted in July 2010 - June 2011. Plant morphological characters were observed and measured and DNA markers were identified using two primers RAPD. Data were analyzed using the program NTsys 2.02. Morphological characters for eight accessions of areca nuts has a similarity level 6%. However, the similarity of six areca nuts accessions, representing three provinces, based on DNA markers was 49%. Individual areca nuts palms are not groupped into their accession, based on either morphological or DNA markers.
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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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