Judul: Effect of Sterilization Method on Successful Initiation of Parica (Schizolobium amazonicum Huber ex Ducke) Seeds In Vitro.
Abstrak: Parica merupakan tanaman yang berasal dari Brazil, yang memiliki pertumbuhan cepat (fast growing). Selama ini perbanyakan parica dilakukan dengan menggunakan benih, untuk itu perlu dicoba perbanyakan vegetatif dengan teknik kultur jaringan. Tujuan penelitian ini adalah menganalisis pengaruh metode sterilisasi terhadap keberhasilan inisiasi parica secara in vitro. Eksplan yang digunakan adalah benih parica. Eksplan benih parica diinisiasi dengan cara mengaplikasikan enam metode sterilisasi (P1-P6) untuk mendapatkan kultur kecambah parica steril. Semua perlakuan metode sterilisasi yang diterapkan untuk inisiasi benih parica memberikan pengaruh yang sama terhadap persentase kultur kecambah parica steril, browning dan kontaminasi. Metode sterilisasi P1-P6 menghasilkan kultur kecambah parica steril yang tinggi (>60%) dengan tingkat browning dan kontaminasi yang rendah. Metode sterilisasi yang direkomendasikan untuk diterapkan dalam proses inisiasi benih parica adalah P5 (sterilisasi luar: praperlakuan 12 jam, sterilisasi dalam: kloroks) karena lebih ekonomis dan praktis dibandingkan dengan perlakuan lainnya. Secara umum, eksplan benih dapat digunakan untuk menghasilkan kultur kecambah parica steril yang selanjutnya dapat dimultiplikasi secara in vitro., Parica is a plant originating from Brazil, which has fast-growing. So far, parica propagation has been done using seeds, so it is necessary to try vegetative propagation using tissue culture techniques. This study aimed to analyze the effect of the sterilization method on the success of parica initiation in vitro. The explants used were parica seeds. Parica seed explants were initiated using six sterilization methods (P1-P6) to obtain sterile parica sprout cultures. All treatments of sterilization method applied for the initiation of parica seed gave the same effect on the percentage of sterile parica sprout culture, browning, and contamination. The P1-P6 sterilization method resulted in high sterile parica sprout cultures (>60%) with low levels of browning and contamination. The recommended sterilization method to be applied in the parica seed initiation process is P5 (external sterilization: 12 hours pretreatment, internal sterilization: Chlorox) because it is more economical and practical than other treatments. In general, seed explants can be used to produce sterile parica sprout cultures, which can then be multiplied in vitro.
Keyword: daya kecambah, kontaminasi, parica (Schizolobium amazonicum), praperlakuan, uji belah

Judul: Pengaruh Teknik Sterilisasi terhadap Keberhasilan Inisiasi Eksplan Paulownia (Paulownia elongata SY. Hu) secara In Vitro
Abstrak: In vitro culture is used as one of the solutions in paulownia propagation. Contamination is a major problem in procedures micropropagation. This study examines the effect of sterilization treatment on the percentage of contamination, browning, and shoot induction paulownia. Sterilization techniques used in the study consisted of four treatments, namely A (Dhitane M-45 0.2 g/100 mL, Agrept 80 WP 0.2 g/100 mL, Bayclin 20%, 15%, 10%), B (Dhitane M-45 2 g/100 mL, Agrept 80 WP 2 g/100 mL, Bayclin 15%, 10%, 5%), C (Dhitane M-45 0.2 g/100 mL, Agrept 80 WP 0.2 g/100 mL, So Klin 20%, 15%, 10 %), and D (Dhitane M-45 2 g/100 mL, Agrept 80 WP 2 g/100 mL, So Klin 15%, 10%, 5%). Sterilization techniques give the same effect on the percentage of contamination, browning, and shoot induction paulownia. Contamination caused by bacteria and fungi is 93.96% and 11.5% respectively. Explants without contamination and browning shows the development of axillary buds. Some of explants produced callus as a response to highly endogenouse hormone. Low concentration of auxin can induced 100% callus formation at the stage of multiplication
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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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