Judul: Penilaian Kondisi Kesehatan Tegakan di Areal Pasca Tambang PT Antam Tbk UBPE Pongkor, Jawa Barat
Abstrak: Problems on recent forest condition in Indonesia are the decreasing of forest quality land clearing for mining industry. PT. Antam Tbk UBPE Pongkor, West Java is a gold mining company located in forest area. Therefore this company should revegetation/reclamation on ex-mining area. To assess the effectiveness on the result of revegation/ reclamation by PT. Antam Tbk UBPE Pongkor, evaluation effectiveness. Evaluation on the health condition is done by using Forest Health Monitoring method in 3 location, e.g revegetation area in 2001, 2003 and 2006. Natural forest is used as control. The result showed that the health of forest at revegetation area in years 2003 and 2006 categorized in unhealthy condition compared with reclamation condition in 2001 and natural forest which on good condition. It is indicated that intensive handling and nursing from PT Antam Tbk UBPE Pongkor is needed in manager reclamation area in years 2003 and 2006 to increase their health in the future., Problems on recent forest condition in Indonesia are the decreasing of forest quality land clearing for mining industry. PT. Antam Tbk UBPE Pongkor, West Java is a gold mining company located in forest area. Therefore this company should revegetation/reclamation on ex-mining area. To assess the effectiveness on the result of revegation/ reclamation by PT. Antam Tbk UBPE Pongkor, evaluation effectiveness. Evaluation on the health condition is done by using Forest Health Monitoring method in 3 location, e.g revegetation area in 2001, 2003 and 2006. Natural forest is used as control. The result showed that the health of forest at revegetation area in years 2003 and 2006 categorized in unhealthy condition compared with reclamation condition in 2001 and natural forest which on good condition. It is indicated that intensive handling and nursing from PT Antam Tbk UBPE Pongkor is needed in manager reclamation area in years 2003 and 2006 to increase their health in the future.
Keyword: the evaluation, PT Antam Tbk UBPE Pongkor, forest condition, FHM Method, Bogor Agricultural University (IPB)

Judul: Assessment of Forest Stand Health Condition  in PT Pesona Khatulistiwa Nusantara, North Borneo Reclamation Area
Abstrak: Reklamasi pasca tambang merupakan kegiatan yang wajib dilakukan oleh perusahaan pertambangan. PT. Pesona Khatulistiwa Nusantara (PT. PKN) merupakan perusahaan yang turut melaksanakan kegiatan reklamasi sebagai upaya dalam memulihkan kembali lahan bekas kegiatan penambangan. Penelitian ini bertujuan untuk mengevaluasi kesehatan hutan pohon-pohon di areal reklamasi PT. PKN. Metode yang digunakan dalam melakukan penilaian kesehatan hutan adalah metode pemantauan kesehatan hutan (Forest Health Monitoring/FHM). Pengambilan sampel dilakukan pada tujuh tahun tanam, yaitu 2013, 2014, 2015, 2016, 2017, 2018, dan 2019 dengan menggunakan metode purposive sampling. Indikator yang diukur dalam metode FHM yaitu produktivitas, kualitas tapak, kondisi tajuk dan kondisi kesehatan pohon. Tegakan pada areal revegetasi secara umum memiliki nilai produktivitas dan kondisi tajuk yang baik, meskipun dengan kondisi kualitas tapak yang rendah. Kerusakan yang banyak ditemukan yaitu tipe kerusakan mati pucuk pada bagian tajuk pohon. Mayoritas tegakan hutan areal revegetasi PT. Pesona Khatulistiwa Nusantara termasuk dalam kategori sehat. Hal ini menunjukkan kegiatan revegetasi pada areal pasca tambang PT. PKN sudah berjalan cukup baik. Pemeliharaan dan evaluasi penanaman dapat dilakukan untuk meningkatkan tingkat kesehatan hutan dan menjaga keberlanjutan areal revegetasi.
Keyword: kesehatan hutan, pasca tambang, mati pucuk

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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