Judul: Upaya Pelestarian Pemanfaatan Ular Sanca Batik (Python reticulatus) dan Ular Sanca Darah Merah (Python brongersmai) Ditinjau dari Aspek Penangkapan dan Pemasarannya di Provinsi Sumatera Utara
Abstrak: Trade in reptiles involves millions of specimens annually, and provides sustenance and income for large numbers of people, particularly in rural communities. It thus benefits many people. Reptiles species of reticulated python (Python reticulatus) and red blood python/short tail python (Python brongersmai) most important in Indonesia trade. The two project spesies are harvested in large numbers in North Sumatra. The trader system, the collecting or harvesting methods, the shared income, the revenue shared, the margin profitable and the input-output ratio analysis from trade activities are outlined in this paper. However, habitat loss and excessive harvesting reduce the numbers that can be harvested annually, reduce the benefits to people, and in extreme cases, may increase the probability of extinction. Successful trade in snakes especially reticulated python (Python reticulatus) and red blood python (Python brongersmai) to developed income is closely to the concept of sustainability. The impacted of commercial harvested activities of that species was unsustainable.
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Judul: Tata Niaga, Karakteristik Habitat dan Parameter Demografi Sanca Batik (Python reticulatus Scheider 1801) yang Dipanen di Propinsi Kalimantan Tengah
Abstrak: Reticulated python (Python reticulatus) has 180.000 heads annual quota. Despite of the commercial use of this species, a good management of the habitat and population is needed for its sustainability. This research was aimed to identify trades, the habitat charactesictics, harvestings, demographyc parameters and morphometry of harvested reticulated python. The research area was within harvesting areas, management authority, snakes collectors and traders in six regency in Central Kalimantan Province. The research method for trades was done by interviewing several actors of management authority, snakes collectors and traders. The habitat was performed by measuring the environment variables at every plot of capturing and nesting habitat, neither the snakes were captured or not. Harvestings, demographyc parameters morphometry variables of harvested snakes at every plot of habitats, catchers and collector were calculated and measured. Descriptive statistical analyzes showed that traders structure were consisted of collectors, middle man and legal permit owner. Kruskal Wallis and Kolmogorov-Smirnov test showed that there was no habitat preference by the reticulated python. Harvesting estimation derived from location of survey was 26.73% at collector stage and about 31.95 % at middle man stage comparing to annual quota of Central Kalimantan Province. Capturing criteria was based on the size of body length, rather than the sex. The sex ratio of captured snakes in collectors was 1:0.72 and middle man was 1:1.07. The age class most captured both in collectors and middle men was the adult male (99% and 89% from all male). This trend occurred because the adult male has a similar size with the young female.
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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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