Judul: Perilaku serangan dan jumlah populasi kutulilin pinus (Pineus boerneri Annand.) pada Pinus merkusii Jungh. et de Vriese
Abstrak: Pinus merkusii Jungh. et de Vriese adalah satu-satunya spesies pinus yang tumbuh asli di Indonesia, dengan berbagai keunggulan (cepat tumbuh, pionir, dan menghasilkan kayu dan getah), sehingga digunakan sebagai tanaman reboisasi dan penghijauan di berbagai wilayah di Indonesia. Serangan organisme pengganggu tanaman (OPT) dapat menurunkan fungsi hutan. Saat ini yang menjadi masalah pada tegakan pinus adalah adanya serangan kutulilin pinus yang dapat menyebabkan kematian pohon. Tujuan penelitian ini adalah (1) Untuk mempelajari perilaku serangan kutulilin pinus, (2) Untuk mengetahui jumlah individu kutulilin pinus dalam populasi dari 3 kriteria serangan (ringan, sedang, dan berat). Penelitian dilakukan dengan menularkan kutulilin pinus yang berasal dari 5 KPH di Jawa Timur. Kutulilin pinus tersebut ditularkan dari cabang pohon pinus yang terserang dari semua tingkat serangan yang berasal dari masing-masing KPH. Penularan dilakukan pada bibit sehat yang berumur 6 bulan dengan dua metode, yaitu metode penularan dari bagian pohon terserang dan penularan langsung dengan kutu hidup. Penularan dilakukan dengan menempelkan cabang pinus yang terserang kutulilin pinus dari tiap tingkat serangan dan masing-masing KPH sepanjang 5cm, penularan dilakukan pada 3 bibit sehat. Penularan langsung dilakukan dengan mengambil lilin pada cabang pinus yang terserang kutulilin pinus dari tiap tingkat serangan dan masing-masing KPH sebesar 1mm dan diletakkan pada ketiak daun bibit pinus, penularan ini juga dilakukan pada 3 bibit sehat.
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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: 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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