Judul: Kandungan logam berat (Pb dan Cd) pada tegakan pidada (Sonneratia alba) di hutan mangrove cagar alam Muara Angke DKI Jakarta
Abstrak: Berbagai jenis industri membuang limbahnya ke sungai yang mengalir ke pantai sehingga mengakibatkan beban pencemaraan di daerah pantai semakin tinggi dan akan menyebabkan penurunan kualitas lingkungan. Salah satu bahan pencemar yang berasal dari limbah industri adalah logam berat. Lingkungan perairan yang tercemar oleh logam berat akan menyebabkan terkontamiasinya berbagai biota di dalamnya, seperti tanaman mangrove yang berada di kawasan Cagar Alam Muara Angke. Penelitian ini dilaksanakan dengan tujuan untuk menge- tahui kemampuan menyerap dan akumulasi logam berat (Pb dan Cd) di bagian akar, batang dan daun pada tegakan pidada (Sonneratia alba). Metode pengambilan sampel pohon dengan membuat dua buah jalur yang memanjang. Pohon sampel yang diambil merupakan perwakilan dari kelas diameter < 10 cm, 10 20 cm, 21 - 30 cm, dan > 31 cm. Bagian pohon yang diambil adalah bagian akar, batang dan daun sebanyak 100 200 gram. Nilai kandungan logam berat (Pb dan Cd) hasil analisis laboratorium di uji dengan metode Kruskal Wallis untuk mengetahui beda nilai kandungan logam berat (Pb dan Cd) pada tiap-tiap bagian pohon, dan metode Wilcoxon Sum Rank Test untuk menguji beda kandungan logam Pb dan Cd pada tiap-tiap pohon pidada. ...
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Judul: Akumulasi Logam Berat Timbal (Pb) dan Cadmium (Cd) pada Pohon Mangrove (Avicennia marina) di Perairan Karangsong, Indramayu.
Abstrak: Mangroves are known to have the ability to absorb and store heavy metals and other contaminants in the body tissues such as leaf and root. This research was carried out in January-March 2013 with the aim to find out the levels of heavy metals Lead (Pb) and Cadmium (Cd) in root and leaf of Avicennia marina, as well as sediments in Karangsong waters, Indramayu. Sampling a root, leave, and sediments was repeated 3 times each. The results showed that levels of Pb in Avicennia marina already passed over the limit of tolerance concentration for plants, whereas the levels of Cd was below detection limit Based on the results, it can be seen Avicennia marina has a low level of bioconcentration factor (BCF), it means that Avicennia marina has a low capability to accumulate heavy metals. Meanwhile the value of translocation factor (TF) is high, mean Avicennia marina has high mobilization from roots to leaves. Based on the findings, it is strongly recommended to control pollutants falling into the aquatic environment, and to enhance mangrove rehabilitation program for ecological and economical function
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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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