Judul: Keanekaragaman Herpetofauna di Areal PT Indocement Tunggal Prakarsa, Tbk Plant Palimanan Cirebon Jawa Barat
Abstrak: PT. Indocement Tbk Cirebon is one of the centre of cement production in Java. The mining activities will affect on the condition of habitats in this area. The purpose of this study is to assess herpetofauna composition and diversity. Data was collected on July 2013 in six sampling locations using VES (Visual Encounter Survey) – time search. There are 22 species with total 161 individuals herpetofauna consisting of 9 species of amphibians and 13 species of reptiles. The highest number of diversity index (Shannon Wiener index) found in Tegakan samping gudang batu bara, Kolam Goa Dalam and Hutan Alam Gunung Blindis, while the lowest number found in Curug Hanjuang. Three sampling points should be prioritize for conservation which are Tegakan samping gudang batu bara, Hulu Sungai Kali Jaya and Curug Hanjuang.
Keyword: habitat, diversity, herpetofauna

Judul: Keanekaragaman Jenis Reptil pada Kantong Hutan di Bogor
Abstrak: Hutan Penelitian (HP) Dramaga dan Kawasan Hutan dengan Tujuan Khusus (KHDTK) Haurbentes di Bogor merupakan contoh hutan yang terfragmentasi di dekat pemukiman. Tujuan penelitian ini yaitu untuk mengukur indeks keanekaragaman, kemerataan dan kekayaan reptil di kantong hutan. Metode pengambilan data menggunakan Visual Encounter Survey (VES) dikombinasi dengan line transect dan passive sampling. Reptil yang ditemukan sebanyak 8 famili dari 16 jenis terdiri atas 85 individu. Beberapa jenis reptil yang ditemukan memiliki status Least Concern (LC) atau beresiko rendah berdasarkan daftar merah IUCN. HP Dramaga memiliki indeks keanekaragaman dan kemerataan tertinggi dibandingkan KHDTK Haurbentes. KHDTK Haurbentes memiliki indeks kekayaan tertinggi dibandingkan HP Dramaga. Kelimpahan tertinggi di HP Dramaga adalah jenis Bronchocela jubata (2.44 ind/jam), sedangkan KHDTK Haurbentes adalah jenis Cyrtocadtylus cf marmoratus (5.91 ind/jam). Kesamaan komunitas tertinggi yaitu HP Dramaga pada jalur 2 dan jalur 3.
Keyword: hutan penelitian dramaga, kantong hutan, keanekaragaman, KHDTK haurbentes, reptil

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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