Judul: Evaluasi Pertumbuhan Beberapa Jenis Dipterokarpa di Areal Revegetasi PT. Kitadin, Kalimantan Timur
Abstrak: The existence of dipterocarp species is very important especially in lowland tropical rain forest. Dipterocarp species have high economic and ecological values. Borneo is one of the region dipterocarp species. Logging has resulted in the decrease of dipterocarp species, moreover, mining industry has worsen this condition. According to IUCN (International Union for Conservation of Nature), that these kinds of plants have been categorized endangered. PT Kiadin in collaboration with Research Center of Dipterocarp Samarinda performed planting trials of various dipterocarp. The experiment was carried out in 2009 in the area of pre-conditioned post-mining area. The planting was done in five locations that had previously been planted with pioneer tree species in which each location had different types of shading. In order to know which dipterocarp species that is the most superior and in which locations these species existed, the growth of several types of dipterocarp in post-mining landscapes of PT. Kitadin was evaluated. This study aimed to identify which types of dipterocarp species that grew the best in various locations of revegetation of PT. Kitadin. Based on the research done, there was a tendency that five dipterocarp species grow well in the shade of waru. However, precentage of these five dipterocarp species life was mostly under the shade of trembesi. Parashorea smythiesii species had greater average height, diameter, and survival rates than those of other species. Thus, this species is a potential species that could be used too planting in the ex mine siter of PT. Kitadin.
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Judul: Evaluasi pertumbuhan tanaman berbagai jenis Dipteropaceae di kebun percobaan Pasir Hantap, Sukabumi
Abstrak: Sekitar seperempat dari jumlah hardwood dalam pasar internasional pada saat ini berasal dari jenis-jenis Dipterocarpaceae, khususnya jenis-jenis endemik yang terdapat di Asia. Melihat kecenderungan eksploitasi hutan sekarang ini kemampuan hutan Dipterocarpaceae diragukan untuk bertahan sampai abad 21, terutama jenis- jenis meranti yang memiliki nilai ekonomis yang lebih tinggi (Ashton, 1979). Sampai saat ini produksi (penebangan) jenis-jenis Dipterocarpaceae yang ditebang masih mengandalkan dari hutan alam (Hutan Hujan Tropika). Dimasa mendatang kuantitas produksi hutan alam semakin menurun, hal ini disebabkan menurunnya kualitas hutan baik dari segi potensi maupun lingkungan. Penelitian ini bertujuan untuk mengetahui tingkat keberhasilan pembangunan dan pengembangan tegakan Dipterocarpaceae, khususnya di Jawa Barat (Sukabumi). Data dikumpulkan secara langsung dari setiap pengukuran dengan menggunakan metoda sensus pada setiap pohon, yang meliputi umur tegakan, keliling pohon (diameter), tinggi (meliputi tinggi bebas cabang dan tinggi total), jumlah semai (seedling) dan pancang (sapling). Data hasil pengukurasn selanjutnya dikonversi untuk mendapatkan besarnya riap diameter, riap tinggi, volume dan riap volume. Pertumbuhan diameter rata-rata yang tertinggi adalah Shorea selanica sebesar 2,87 cm/tahun dan yang terkecil adalah Hopea sangal sebesar 1,07 cm/tahun. Secara keseluruhan riap diameter setiap jenis cukup tinggi, diatas 1 cm/tahun (Masano, 1985). Pertumbuhan rata-rata tinggi yang tertinggi adalah Hopea odorata sebesar 0,84 m/tahun dan yang terkecil adalah Shorea leprosula sebesar 0,19 m/tahun Pertumbuhan volume rata-rata yang tertinggi adalah Shorea selanica sebesar 0,33 m³/tahun dan yang terkecil adalah Hopea sangal sebesar 0,07 m³/tahun...
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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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