Judul: Habitat Characteristics of Rafflesia rochussenii Teijsm. et Binn. in Cimande Resort, Gunung Gede Pangrango National Park
Abstrak: Rafflesia rochussenii is a rare and protected plant species. This species is found in Cimande Resort, Gunung Gede Pangrango National Park, Bogor, West Java. The purpose of this study is to describe the habitat characteristics of Rafflesia rochussenii in Cimande Resort, both biotic and abiotic components, and to explain its management program. The method used is purposive sampling with circular plots with a radius of 17.8 m. Literature study was done to find supporting data. Results identified 57 Rafflesia individuals were found consisting of alive and dead flowers as well as alive and dead buds. The host was Tetrastigma leucostaphylum. The dominating species at the tree, sapling, seedling and undergrowth level were Schima wallihcii, Castanopsis acuminatissima, Aspnlenium nidus, and Cinchona pubescens, respectively. Six species of animals were identified. Rafflesia habitat is found in the altitude of 840-1,360 masl, a slope of 10% -88%, average temperature of 19°C and relative humidity ranging from 80-90%. Soil pH ranges from 5-6.5, soil color is reddish brown to yellow. Leaf Area Index value ranges from 1.85-2.11. Management done by the National Park is inventory and monitoring.
Keyword: abiotic, biotic, habitat, Rafflesia rochussenii

Judul: Population and Habitat Conditions of Rafflesia patma Blume in the Pangandaran Nature Reserve, West Java
Abstrak: Rafflesia patma Blume merupakan tumbuhan langka dan dilindungi yang tersebar di pulau Jawa, salah satunya di Cagar Alam Pangandaran. R. patma memiliki ciri biologis yang berbeda dengan tumbuhan lain yaitu memerlukan kondisi lingkungan tertentu untuk mendukung perkembangbiakan dan pertumbuhannya. Tujuan penelitian ini yaitu untuk mendeskripsikan kondisi dan menganalisis faktor biotik juga abiotik pada habitat R. patma di Cagar Alam Pangandaran. Metode yang digunakan adalah purposive sampling dengan plot lingkaran berukuran jari-jari 17,8 m. Hasil identifikasi ditemukan 202 individu pada 15 plot penelitian yang terdiri dari kuncup mati, kuncup hidup dan mekar mati. Tumbuhan inang yang ditemukan merupakan spesies Tetrastigma leucostaphylum. Kondisi vegetasi yang mendominasi pada tingkatan pohon, pancang dan semai yaitu Vitex pubescens, Dyospyros oblonga dan Flacourtia rukam. Satwa yang ditemukan pada habitat R. patma sebanyak 8 spesies. Habitat R. patma ditemukan pada ketinggian 40 – 120 mdpl, kemiringan 4 – 35 %, jenis tanah lempung berwarna coklat kemerahan sampai abu-abu kehitaman, suhu rata-rata 27,4ºC, kelembapan 60-94% dan nilai indeks luas daun berkisar 1,82 – 2,15., Rafflesia patma Blume is a rare and protected plant that is spread across the island of Java, one of which is the Pangandaran Nature Reserve. R. patma has different biological characteristics from other plants, namely that it requires certain environmental conditions to support its reproduction and growth. The aim of this research is to describe the conditions and analyze biotic and abiotic factors in the R. patma habitat in the Pangandaran Nature Reserve. The method used was purposive sampling with a circle plot measuring 17.8 m radius. The identification results found 202 individuals in 15 research plots consisting of dead buds, live buds and dead blooms. The host plant found was the Tetrastigma leucostaphylum species. The vegetation conditions that dominate at the tree, sapling and seedling levels are Vitex pubescens, Dyospyros oblonga and Flacourtia rukam. Eight types of animals were found in the R. patma habitat. The habitat of R. patma is found at an altitude of 40 – 120 meters above sea level, slope 4 – 35%, clay soil type reddish brown to blackish gray, average temperature 27.4ºC, humidity 60-94% and leaf area indeks value around 1, 82 – 2.15.
Keyword: abiotik, biotik, habitat, populasi, Rafflesia patma Blume

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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