Judul: Morphometrics and Body Weight Gain of Male House Geckos (Gekko gecko) at Different Temperatures
Abstrak: Tokek rumah (Gekko gecko) merupakan salah satu jenis tokek yang mempunyai nilai ekonomi tinggi. Hal ini terbukti dari tokek yang sudah lama dijadikan komoditas ekspor di Eropa, Amerika dan Asia. Penelitian ini bertujuan untuk menganalisis morfometrik dan pertambahan bobot badan tokek rumah jantan (Gekko gecko) pada perlakuan suhu berbeda. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) dengan tiga perlakuan suhu berbeda, yaitu suhu 27,0-28,9 °C (P1), suhu 29,0-30,9 °C (P2), dan suhu 31,0-32,9 °C (P3) dengan pengulangan sebanyak empat kali. Penelitian ini menggunakan 12 ekor tokek jantan dengan berat badan 45-65 gram. Variabel yang diamati dalam penelitian ini adalah suhu dan kelembapan lingkungan, panjang ekor, panjang badan, panjang paha, panjang lengan atas, panjang moncong sampai kloaka, panjang total dan bobot badan. Hasil penelitian menunjukkan suhu 29,0-30,9 °C memberikan pertambahan bobot badan yang tinggi. Suhu yang berbeda tidak berpengaruh nyata terhadap morfometrik tokek rumah jantan tetapi berpengaruh nyata terhadap pertambahan bobot badan., Tokay geckos (Gekko gecko) is a type of gecko that has high economic value. This is proven by geckos which have long been used as an export commodity in Europe, America and Asia. This study aims to analyze the morphometrics and body weight gain of male house geckos (Gekko gecko) at different temperature treatments. This research used a Completely Randomized Design (CRD) with three different temperature treatments, namely 27,0-28,9 °C (P1), 29,0-30,9 °C (P2), and 31,0-32,9 °C (P3) with repetition four times. This study used 12 male geckos with a body weight of 45-65 grams. The variables observed in this study were environmental temperature and humidity, tail length, body length, femur length, humerus length, snouth vent length, length of total and body weight. The research results showed that a temperature of 29,0-30,9 °C provided a high increase in body weight. Different temperatures did not have a significant effect on the morphometrics of male house geckos but had a significant effect on body weight gain.
Keyword: bobot badan, morfometrik, Suhu, tokek rumah, Body weight, tockay gecko, morphometrics, temperature

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: 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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