Judul: Potensi Beberapa Jenis Tanaman sebagai Atraktan dalam Pengendalian Hayati Hama Keong Mas (Pomacea canaliculata L.).
Abstrak: Keong mas (Pomacea canaliculata L.) adalah hewan invasif yang menjadi hama padi di areal persawahan. Pengendalian keong mas dapat dilakukan secara alami menggunakan tanaman sebagai atraktan. Penelitian ini bertujuan mengeksplorasi jenis tanaman dan waktu pengamatan yang membuat keong mas paling banyak mendekati tanaman. Penelitian dilakukan pada kolam berukuran 1.8 m x 1.8 m yang dibagi menjadi 9 blok. Sebanyak 200 individu keong mas berukuran kecil dan besar diletakkan pada blok ke-5 (di tengah), kemudian delapan blok di sekitarnya diletakkan satu jenis tanaman yang berbeda. Perpindahan keong mas mendekati jenis tanaman yang disukai diamati setiap 1 jam dari pukul 06.00 - 18.00 WIB. Pengamatan diulang sebanyak lima kali pada lima hari yang berbeda. Hasil pengamatan menunjukkan bahwa keong mas kecil paling banyak berpindah mendekati daun talas belitung (Xanthosoma sagittifolium) (7.9 ± 4.0 individu), sedangkan keong mas besar pada daun pepaya (Carica papaya) (7.1 ± 4.4 individu). Kedua tanaman tersebut yang paling berpotensi dijadikan atraktan. Jumlah keong mas pada tanaman ditemukan paling banyak pada pukul 18.00 WIB. Kata kunci: ABSTRACT LISDASARI PRIANDHINI. The Potenty of Several Plant Types as Attractants in Biological Control of Golden Apple Snail (Pomacea canaliculata L.). Supervised by TRI HERU WIDARTO and TATIK CHIKMAWATI. Golden apple snail (Pomacea canaliculata L.) is an invasive animal that becomes a destructive pest in rice fields. Controlling this snails can be done naturally using plants as attractants. This study aims to explore species plants and the duration of time needed that make the largest number of snails attracted to the plants. The study was conducted on a 1.8 m x 1.8 m pool divided into 9 blocks. A total of 200 small and large snails are placed in the 5th block (in the middle), then eight different blocks surrounding it were filled with one species of plant. The movement of snails toward a species of plant was observed every 1 hour from 06.00 AM to 06.00 PM. This trial was repeated five times in five consecutive days. The observations showed that most small snails moved towards belitung taro leaves (Xanthosoma sagittifolium) (7.9 ± 4.0 individu), while most large snails moved towards papaya leaves (Carica papaya) (7.1 ± 4.4 individu). Those two types of plants are the most potentially used as attractants. In addition, the largest number of snails found in the plants occurs at 18.00 WIB.
Keyword: Carica papaya, hama padi, keong mas, tanaman atraktan, Xanthosoma sagittifolium

Judul: Daya Hidup Keong Mas (Pomacea canaliculata Lamarck) Setelah Terpapar Ekstrak Daun Pepaya dan Ekstrak Daun Sirih
Abstrak: Hama keong mas masuk ke-Indonesia tahun 1980-an, hama ini menyebabkan penurunan produktivitas padi. Pengendalian keong mas saat ini umumnya menggunakan pestisida kimia dengan kerusakan lingkungan sebagai efek sampingnya. Oleh karena itu diperlukan metode alternatif seperti penggunaan pestisida nabati yang aman bagi lingkungan. Penelitian ini bertujuan mengetahui pengaruh pestisida nabati ekstrak daun pepaya dan ekstrak daun sirih terhadap daya hidup keong mas. Keong yang digunakan memiliki ukuran diameter operkulum 1, 3, 5, 7, 9, 11, 13, dan 15 mm. Ekstrak daun pepaya dan ekstrak daun sirih yang digunakan berkonsentrasi 0, 1, 10, 50, dan 100 g/l dengan tiga ulangan. Daya hidup keong diamati selama 24, 48, dan 72 jam di dalam toples plastik. Hasil penelitian menunjukkan ekstrak daun pepaya lebih efektif menurunkan daya hidup keong mas daripada ekstrak daun sirih. Efektivitas ekstrak daun pepaya dan daun sirih tidak tergantung pada ukuran keong tetapi tergantung pada konsentrasi dan waktu. Semakin tinggi konsentrasi, ekstrak semakin efektif membunuh keong mas. Demikian pula dengan waktu, semakin lama waktu pemaparan, ekstrak bekerja semakin efektif membunuh keong. Kemampuan ekstrak daun pepaya dan daun sirih membunuh keong mas mungkin karena kandungan saponin, flavonoid, papain, dan fenol.
Keyword: olden apple snail (GAS), papaya leaf extract, betel leaf extract, the survival

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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