Judul: Perdagangan reptilia sebagai binatang peliharaan di DKI Jakarta
Abstrak: DKI Jakarta in the world of wildlife trade is often referred as yellow dots, a city vulnerable to illegal trade. Wildlife trade in DKI Jakarta consists not only on ornamental fish, mammals and birds, but even reptiles. This study aims to describe trade locations, identify species of trade and analyze preferences of pet reptiles. The study was conducted in five traditional markets and 35 pet shops in DKI Jakarta, using interviews and investigative methods. I also carried out survey on cyber-market trade and interviews to pet reptile owners. The study was carried out from August 20th to November 20th, 2010. A total of 52 species (26 species of turtles, 23 snakes and three lizards) were traded on traditional markets, and 46 species (21 species of turtles, 19 species of snakes and six species of lizards) at the pet store. In traditional markets the common species sold are local species, but not on pet stores where most are imported species. In total, survey found five species of protected reptiles according to PP No. 7 of 1999, four species of Appendix I CITES’s reptiles and six species listed as critically endangered by IUCN Red List. Three forums in internet carried out cyber markets of pet reptiles. The most favorite pet reptiles were snakes, especially the ball python (Python regius).
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Judul: Herpetofauna Trade as Pets in Greater Jakarta
Abstrak: Tren satwa peliharaan dari kucing dan anjing telah berkembang menuju satwa peliharaan eksotis. Herpetofauna sebagai salah satu satwa liar eksotis mempunyai nilai ekonomi tinggi yang meningkat setiap tahunnya. Herpetofauna menjadi salah satu satwa peliharaan yang popular diperdagangkan di pasar konvensional maupun platform online. Penelitian mengenai perkembangan satwa peliharaan masih terbatas, sehingga penelitian ini bertujuan untuk menelaah perdagangan herpetofauna sebagai satwa peliharaan di pasar hewan dan petshop, serta menganalisis cara pembelian konsumen dalam memperoleh herpetofauna. Penelitian dilakukan di sembilan pasar hewan dan 79 petshop di Jabodetabek menggunakan metode investigasi. Pengambilan data juga ditujukan kepada pemilik herpetofauna dengan kuesioner melalui google form. Hasil penelitian ditemukan sebanyak 45 jenis (41 jenis reptilia dan 4 jenis amfibia) berada di pasar hewan dan 88 jenis (53 jenis reptilia dan 35 jenis amfibia) ditemukan di petshop. Berdasarkan asal penyebarannya, jenis herpetofauna yang diperdagangan pada pasar hewan dan petshop didominasi oleh jenis asing sebanyak 72 jenis (69%), sedangkan jenis lokal sebanyak 32 jenis (31%). Hanya ditemukan satu jenis herpetofauna di pasar hewan, Python bivittatus (sanca bodo), yang termasuk dalam satwa dilindungi menurut Permen LHK No. 106 tahun 2018. Trachemys scripta (kura-kura Brazil) merupakan jenis yang paling banyak dijual. Hasil kuesioner menunjukkan bahwa pemilik herpetofauna paling banyak selalu memilih membeli satwa peliharannya melalui platform online, dibandingkan dengan cara konvensional. Pergeseran perdagangan herpetofauna dari konvensional menuju perdagangan online menunjukkan adanya perluasan jangkauan proses jual-beli herpetofauna. Platform online telah menjadi alternatif media perantara dalam perdagangan satwa.
Keyword: perdagangan, amfibia, reptilia, satwa peliharaan

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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