Judul: Uji Vigor Benih Acacia mangium Willd. Hasil Mutasi
Abstrak: Induksi mutasi tanaman dengan iradiasi sinar gamma merupakan salah satu cara yang dapat digunakan untuk meningkatkan keragaman genetik tanaman. Tujuan penelitian ini adalah menganalisis vigor benih mangium yang sudah diberi perlakuan mutasi. Perlakuan mutasi dilakukan terhadap benih mangium M0. Benih mangium yang digunakan adalah benih mangium M2 dan benih mangium kontrol (bukan hasil mutasi). Serangkaian uji pertumbuhan, uji stres, dan uji biokimia; dilakukan untuk mengetahui vigor benih mangium. Pada uji pertumbuhan, benih mangium M2 memiliki nilai daya kecambah, tinggi kecambah, berat kering, dan indeks vigor yang lebih tinggi dibandingkan dengan benih mangium kontrol. Pada uji stres yang terdiri dari uji Hiltner, uji pengusangan cepat, dan uji kejenuhan nilai daya kecambah benih mangium M2 lebih tinggi dibandingkan dengan benih mangium kontrol. Pada uji biokimia, nilai konduktivitas listrik benih mangium kontrol lebih besar dibandingkan dengan benih mangium M2. Secara umum, benih mangium M2 memiliki vigor yang lebih tinggi dibandingkan dengan benih mangium kontrol., Induction of plant mutation using gamma irradiation is one of the methods that can be applied to improve the genetic diversity of plants. This study aims to analyse the vigour of mangium seeds treated by mutation. Mutation treatment was administered to M0 of mangium seed. We used M2 mangium seeds and control mangium seeds (without mutation treatment) in this study. Several assays such as growth, stress, and biochemical tests were conducted to determine mangium seeds vigour. The growth test showed that M2 mangium seeds had higher germination values, germination height, dry weight, and vigour index than control mangium seeds. The stress test consisting of Hiltner test, accelerated ageing test, and saturation test of the germination value of M2 mangium seeds was higher than control mangium seeds. In the biochemical test, the electrical conductivity value of control mangium seeds was more significant than M2 mangium seeds. In general, M2 mangium seeds had higher vigour than control mangium seeds.
Keyword: accelerated ageing test, electrical conductivity test, Hiltner test, mangium (Acacia mangium), seed saturation test

Judul: Karakterisasi Mangium (Acacia mangium Willd.) Hasil Radiasi Sinar Gamma.
Abstrak: Pengadaan bibit unggul Acacia mangium Willd. dapat dilakukan melalui program pemuliaan tanaman, salah satunya dengan radiasi. Tanaman hasil radiasi diseleksi untuk menjadi indukan perbanyakan tanaman. Penelitian ini bertujuan untuk mengkarakterisasi mangium hasil radiasi sinar gamma dosis 0, 5 dan 15 krad berdasarkan morfologi, kerapatan kayu dan ketahanan terhadap hama-penyakit. Pengamatan morfologi dilakukan pada diameter, tinggi, volume, tinggi bebas cabang (TBC), kelurusan batang, cabang permanen, tajuk dan jumlah cabang. Data morfologi dianalisis dengan uji-F berdasarkan hasil rancangan acak kelompok (RAK), sedangkan kerapatan kayu dianalisis dengan uji non-parametrik Kruskall- Wallis. Hasil analisis menunjukkan, pemberian perlakuan hanya berpengaruh nyata pada TBC, sedangkan blok berpengaruh nyata pada tinggi pohon, TBC, kelurusan batang dan cabang permanen. Tidak ada perbedaan nyata pada kerapatan kayu. Intensitas serangan hama-penyakit pada mangium sebesar 9.75%, termasuk ringan dan tidak merugikan. Kandidat pohon plus yang terpilih berasal dari perlakuan kontrol dan radiasi 5 krad.
Keyword: Acacia mangium, gamma, karakterisasi, mangium, radiasi

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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