Judul: Uji Klon Jati Unggul Nusantara (JUN) Umur 30 Bulan Di Kabupaten Purwakarta, Jawa Barat
Abstrak: Jati Unggul Nusantara (JUN) is known as commercial planting stock material that is vegetatively propagated by means of shoot cutting technique. JUN is claimed to be fast growing. However, scientific information on the growth of selected JUN clones from clonal tests is still lacking. The objective of the study were i) to review performance of 41 JUN clones, ii) to estimate their genetic parameters and iii) to assess the effect of microsites on tested JUN clones. Genetic assessment of JUN clones was carried out in Purwakarta, West Java in a Randomized Complete Block Design (RCBD) consisting of 41 clones. The clones were planted on 4 microsites that were differentiated by fertilizer doses and spacings. The results showed that generally survival rates were high (>90%). In addition, repeatability at 30 months after planting was about = 0.948 (diameter) and = 0.699 (height), respectively. While genetic and phenotypic correlations between diameter and height were rG=0.315 and rP=0.864, respectively. The best microsite supporting growth of JUN clones at 30 months was found on microsite 1, namely spacing 3 m x 4 m with 3 kg organic fertilizer, while the best straight stem form (around 45% of the population) was observed on microsite 2.
Keyword: stemform, repeatability, genetic correlation, fenotipe correlation, Jati Unggul Nusantara (JUN)

Judul: Uji Pertumbuhan Klon Jati Unggul Nusantara (JUN) umur 15 bulan di Kabupaten Purwakarta, Jawa Barat
Abstrak: Jati (Tectona grandis L.f) merupakan salah satu jenis kayu unggulan di Indonesia. Sifat fisik seperti tekstur, corak, keawetan, serta kekuatannya menjadikan kayu jati cocok untuk dijadikan kayu pertukangan hingga mebel yang bernilai ekonomis tinggi. Jati Unggul Nusantara (JUN) merupakan salah satu nama dagang (merek) jati yang diklaim memiliki sifat unggul yaitu, cepat tumbuh, dan dapat dipanen mulai umur 5 tahun dengan target diameter 20 cm. Uji keragaan klon JUN diperlukan untuk memverifikasi sifat-sifat yang diinginkan tersebut serta untuk menentukan klon-klon unggul diantara klon-klon lain yang diuji (n=41 klon) untuk rekomendasi penanaman masal. Uji klon JUN menggunakan rancangan acak lengkap berblok yang terbagi dalam 4 tapak mikro, 4 replikasi, dan pada setiap replikasi terdapat 4 tree plot. Hasil pengamatan pada uji klon JUN berumur 15 bulan di Kabupaten Purwakarta menunjukkan nilai repeatability klon (𝑅𝑐 2) yang cukup tinggi yaitu untuk karakter diameter 𝑅𝑐 2=0,86 dan untuk karakter tinggi 𝑅𝑐 2=0,73. Nilai korelasi antara karakter tinggi dan diameter juga menunjukkan korelasi yang kuat yaitu untuk korelasi genetik sebesar 0,88 dan untuk korelasi fenotipik sebesar 0,80. Nilai persen hidup di lapangan untuk JUN berumur 15 bulan juga sangat tinggi yaitu >90%. Tapak mikro terbaik untuk JUN berumur 15 bulan ini adalah pada tapak mikro 3 (jarak tanam 5x2 m dengan pupuk dasar 3 kg).
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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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