Judul: Analisis probit untuk pembandingan tingkat toksisitas ekstrak kasar akar tuba dan buah pinang
Abstrak: Golden snail pests become a very important issue in any lowland rice farming. Generally farmers control this pests mechanically by taking existing golden snail. In addition, farmers also use synthetic pesticides to kill golden snail. However, both ways are not effective enough. One way to overcome this problem is to use a plant pesticide tuba root and areca-nut fruit coarse extract. It is known that both of these pesticides can cause death of golden snail. But the effective dose and relative toxicity of the two plant pesticides is not yet known, but it is important to know especially in dealing with critical issues. Determination of effective dose can be done through the determination of the lethal concentration (LC), for example, LC50 and LC90. This research use probit analysis to modeling a connection between golden snail death response (binary data) and both of plant pesticides concentration. Analysis result show that areca-nut coarse extract are more effective than tuba root extract since toxicity level of areca-nut (LC50 = 0.381 g/l and LC90 = 1.098 g/l) higher than tuba root (LC50 = 0.675 g/l and LC90 = 1.182 g/l). Supported by the terms of practically to obtain and how to manufacture, areca-nut coarse extract is recommended for use in eradication of golden snail pests.
Keyword: 

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: 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.
Keyword: