Judul: Status Kesehatan Hutan di Areal Reklamasi Tambang Batubara PT Indominco Mandiri Kalimantan Timur
Abstrak: Usaha pertambangan dengan teknik penambangan terbuka mengakibatkan kerusakan lingkungan dan harus segera dilakukan reklamasi lahan bekas tambang. Kegiatan reklamasi dan revegetasi lahan bekas tambang telah dilakukan pada areaarea yang telah selesai ditambang, namun saat ini belum diketahui status kesehatan hutan tersebut. Metode pemantauan kesehatan hutan merupakan salah satu cara untuk mengevaluasi kondisi kesehatan tegakan hasil dari revegetasi. Metode FHM akan memberikan informasi status, perubahan, kecenderungan dan saran manajemen kepada pengelola agar hutan hasil reklamasi memiliki kondisi dan fungsi sesuai tujuan pembangunannya. Tujuan dari penelitian ini adalah untuk menilai status kesehatan hutan di areal reklamasi PT Indominco Mandiri Kalimantan Timur berdasarkan metode FHM. Penelitian ini menggunakan indikator vitalitas, kualitas tapak dan biodiversitas tumbuhan bawah. Areal penelitian sebanyak 4 klaster plot, dengan tahun tanam 2004, 2006, 2008 dan 2010. Tipe kerusakan didominasi oleh kerusakan cabang patah atau mati (kode 22) dan lokasi kerusakan didominasi pada ranting. Status kesehatan tegakan hasil revegetasi lahan bekas tambang di PT Indominco Mandiri menunjukkan nilai sehat pada tegakan umur 7 tahun dan nilai sedang pada tegakan umur 5 tahun, 9 tahun dan 11 tahun. Kerusakan tegakan terbesar disebabkan oleh cabang patah atau mati, liana dan daun berubah warna (tidak hijau). Kesuburan tanah yang rendah terdapat pada tegakan umur 11 tahun, 9 tahun dan 7 tahun serta pada tegakan umur 5 tahun termasuk sangat rendah.
Keyword: Pemantauan kesehatan hutan, pertambangan, reklamasi

Judul: Status Kesehatan Hutan di Areal Reklamasi Tambang Batubara PT Berau Coal Kalimantan Timur.
Abstrak: Mining activity always related to land conversion that lead to the destruction of forest resources, among others biodiversity loss, land fertility degradation dan toxicity of land. Every mining license holder is required to held a reclamation activity in order to returning forest area and degraded land into its proper function. Forest Health Monitoring (FHM) is a method which can be used to monitor, assess and report the current forest status, changes and long term trends in forest ecosystem health by using measurable ecological indicators for making management decision. The aim of this study was to assess forest health status in reclamation areal in Sambarata Site PT Berau Coal using FHM method. Assessment was done using indicators such as productivity, site quality, vitality (tree damage condition and crown condition) and undergrowth biodiversity. Total amount of established plot was 20 plots (5 cluster plots), it was located in planting year of 2011, 2010, 2009, 2008 and 2007. The result showed that the forest health status was classified into fair with the values of 20, 23, 26, 26 and 26 of 50 respectively.
Keyword: FHM, forest health, mining

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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