Judul: Pengaruh Serangan Kutulilin Pinus (Pineus boerneri) Terhadap Kualitas Getah Tusam (Pinus merkusii Jungh, at de Vriese)
Abstrak: Pine (Pinus merkusii Jungh, at de Vriese) is one type of Indonesia native plant which grows fast and produces lumber and resin. Pine wood is a type of trade timber in Indonesia and its latex can be processed as rosin and turpentine. Since 1997, in Indonesia P. merkusii has been attacked by Pineus boerneri (Pine Woolly Adelgide) which can cause damage and even death of the plant. This research has purpose to know the effect of P. boerneri on the quality of P. merkusii latex. The sample trees were determined by purposive sampling and with five replications for each attack criterion (no attack, mild, moderate and severe). The latex was obtained by tapping directly with “Koakan” method. The harvesting of latex every three days for three times the collection. The parameters observed are color, water content, dirt level, acid number and base number of the latex. The result of this research shows that the Pine Woolly Adelgide attacks can affect the color, dirt level, water content, acid number and base number of the latex. The mild, moderate and severe attack levels of Pine Woolly Adelgide can make the dirt level of the latex become higher than normal one, while the color, moisture content, acid number and base number of the latex are only affected by moderate and severe attacks of Pine Woolly Adelgide.
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Judul: Distribution of attack by wooly adelgid (Pinus boerneri) on pine stand (Pinus merkusii) (Case study in KPH Sumedang, Perum Perhutani Unit III, West Java and Banten)
Abstrak: Pine tree is known as one of the Indonesian commercial timber. Timber produced by pine tree has clear yellowish white color, which make it very attractive to be used for various furniture, house building, floor, furniture and various other products. Pine trees which are abundantly planted as plantation forest have some risk to be attacked by pest and disease. Monoculture condition of plantation forest which tends to be homogeneous, increases the tendency of attack by pest and diseases. At present, there is found pest species of the order Hemiptera which is known by the term wooly adelgid (Pineus boerneri). Pest wooly adelgid which attacks P. merkusii in Indonesia constitutes a new pest which was originated from outside Indonesia (exotic) and at present has not been found in other kinds of pine trees. Knowledge on distribution and condition of attack by wooly adelgid in pine stand is needed to determine the natural control action through environmental modification to create environment which is unfavorable for the wooly adelgid pest.
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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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