Judul: Karakteristik usaha gaharu alam (Aquilaria malaccensis) di Provinsi Bengkulu: studi kasus Kabupaten Bengkulu Selatan, Kabupaten Kaur, dan Kabupaten Seluma
Abstrak: Forest is a natural resource that can be used for the people walfare. One of forest product which has potential to be used is resin agarwood. Gaharu has high sold price with production qualification that consist of gubal, kemedangan and ash. Each of product containsOleo Chromone which are produce unique aroma, so that it often used in many industries such as parfum industry, cosmetic industry and religion ritual need. High demand of agarwood cause the demand of it increase more, so that influence to the decrease more, but the agarwood exertion process still do so that it is important to do investigation of natural agarwood characteristics nowdays. This Research aims to know the characteristic of the natural agarwood exertion in Bengkulu Province, that consist of the characteristic of agarwoodenterprenuer (finder small, collector seller and big collector seller), the process of agarwood exertion, kinds and quality characteristic, marketing system and also policy in agarwood exertion. The methodology of this research is qualitative by describing the characteristic of natural agarwood exertion and quantitative by counting the margin of profit. There are three groups of gaharuenterprenuer namely: agarwood finder, small collector and big collector. The group of agarwood finders do the gaharu exertion. On the process of agarwood exertion need the specific skill about the characteristic of tree that contain agarwood. The products then sell to collector seller of agarwoodthrough its selling channel. The selling of agarwood begun by determining the condition and price, where there are seven agreed quality. This quality class is so determining the price, better quality of agarwood higher the price and lower quality of agarwood lower the price. The differences of price from each quality of agarwood can reach 3-15 times from the increasing each quality. Enterprenuer have role in determining namely big collector seller so that margin of highest price gotten by them is 1,4-2 multiple times with their income that they gottetn 28 times from income of agarwood finders group. In order to manage marketing of agarwood, government determines policy in the form of quota in a year, the license that is given to big collector seller in 5 year and the rate of dues determined based on gubal class Rp 20.000,-/kg and kemedanganRp 2.000,-/kg.
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Judul: Karakteristik Sifat Fisis dan Kecepatan Gelombang Ultrasonik Pohon Penghasil Gaharu Jenis Aquilaria microcarpa Baill.
Abstrak: As the increasement of its usefulness and demand, more people tried to get agarwood in any ways. Those can be lead threaten on its existence. By this condition, an innovation to detect agarwood inside the tree is necessary. The objective of this research was to know the physical properties and ultrasonic propagation characteristics of Aquilaria microcarpa Baill. The trees used in this research were 60 A. microcarpa with 3 different treatment condition, i.e trees without any infections as control, trees which infected by fungi for one time and infected three times. The testing were conducted by radial and longitudinal direction. Radial Testing were conducted to know the internal condition of the tree. Meanwhile, longitudinal testing were performed to predict the elasticity of the wood. Physical properties samples were taken from the bark to the core of the tree. Ultrasonic propagation testing in radial direction showed that its value at 20 cm, 130 cm and 200 cm of the tree height of the control trees were 969 m s-1, 915 m s-1 and 943 m s-1 respectively. For those height, ultrasonic propagation value at trees which infected for one time were 955 m s-1, 913 m s-1 and 911 m s-1respectively, meanwhile at the trees which infected for three times were 1008 m s-1, 928 m s-1 and 953 m s-1 respectively. At the longitudinal testing, the average values of ultrasonic propagation were 3366 m s-1, 3188 m s-1 dan 2817 m s-1 for control, one inoculation, and three inoculations trees, respectively. The dynamic modulus of elasticity (MOEd) value of the control trees, the trees which infected for one time and three times were 9.194 GPa, 8.498 GPa and 5.703 Gpa, respectively. Statistical analysis revelaed that the interaction between tree height measurement and treatments were not significantly influenced for ultrasonic velocity tested radially as well as single factor for both height measurement and treatments. Meanwhile, inoculation treatments were significant difference on ultrasonic velocity testing longitudinally and dynamic MOE. The average value of moisture content of the wood was 53.18%, while the density was 0.75 g cm-3.
Keyword: ultrasonic propagation, physical properties, Aquilaria microcarpa Baill, Agarwood

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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