Judul: Morphometrics and Body Color Characteristics of Male and Female Tokay Gecko (Gekko gecko)
Abstrak: Tokek rumah (Gekko gecko) merupakan reptil dari famili Gekkonidae yang bernilai ekonomi tinggi jika telah mencapai berat dan ukuran tubuh tertentu. Tingginya permintaan ekspor tokek rumah sebagai bahan obat-batan mengakibatkan perburuan tokek rumah menjadi tidak terkendali. Saat ini status tokek rumah menjadi Appendiks II. Perlu dilakukan pembudidayaan tokek rumah yang dimulai dari pengenalan morfometrik dan karakteristik tokek rumah guna mencegah perburuan yang tidak terkendali. Penelitian ini bertujuan mengamati perbedaan ukuran morfometrik tokek jantan dan betina, serta karakteristik warna tubuh tokek rumah (Gekko gecko) berupa warna dasar kulit, bintik, dan garis batas. Penelitian dilakukan dengan 10 ekor tokek jantan dan 10 ekor tokek betina. Penelitian menggunakan metode T-test untuk menganalisis data morfometrik dan metode deskriptif untuk menganalisis data karakteristik warna tubuh tokek. Hasil penelitian menunjukkan adanya perbedaan morfometrik antara tokek jantan dan betina yang terdapat pada ketebalan pangkal ekor, lebar dan panjang kepala, panjang moncong hingga kloaka, serta pada karakteristik warna tubuh., The tokay gecko (Gekko gecko) is a reptile from the Gekkonidae family which has high economic value when it reaches a certain body weight and size. The increased demand for the tokay gecko's export as a medicinal ingredient resulted in the hunting of the house gecko getting out of control. Currently, the tokay gecko's status became Appendix II. It is necessary to breeding tokay geckos starting from the introduction of morphometrics and characteristics of tokay geckos to prevent uncontrolled hunting. This study aims to observe differences in the morphometric sizes of male and female tokay geckos and the body color characteristics of the tokay gecko (Gekko gecko) in the form of primary skin color, spots, and outlines. The study was conducted with 10 male and 10 female tokay geckos. The study used the T-test method to analyze morphometric data and descriptive approaches to analyze data on the tokay gecko's body color characteristics. The results showed morphometric differences between male and female tokay geckos in the thickness of the tail base, head width and length, snout vent length, and body color characteristics.
Keyword: body color, body size, morphometric, reptile, tokay geckos

Judul: Morphometrics and Body Weight Gain of Female Tokay Gecko (Gekko Gecko) Cared Under Different Light Color
Abstrak: Tokek rumah (G. gecko) merupakan hewan nokturnal yang memiliki kemampuan untuk melihat dalam keadaan kurang cahaya. Keberadaan tokek rumah (G. gecko) saat ini terancam akibat perburuan liar hingga memiliki status apendiks II. Penelitian ini bertujuan untuk menganalisis pengaruh perbedaan warna cahaya lampu terhadap morfometrik dan pertambahan bobot badan tokek rumah betina. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) dengan lima perlakuan warna cahaya lampu dengan tiga tokek rumah betina setiap perlakuan dan diuji lanjut duncan. Hasil penelitian menunjukkan bahwa perbedaan warna pencahayaan lampu memengaruhi pengukuran morfometrik dan pertambahan bobot badan. Tokek rumah betina yang terpapar dengan cahaya hijau memiliki pertambahan bobot badan yang lebih tinggi secara signifikan (P
Keyword: morphometrics, lights color, gekko gecko, body weight

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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