Judul: Keawetan Alami Beberapa Jenis Kayu Indonesia Kurang Dikenal dari Kampus IPB Dramaga terhadap Serangan Rayap
Abstrak: The objective of this research was to evaluate the natural durability of Nine Indonesian lesser known species against subterranean termite (Coptotermes curvignathus Holmgren) and dry wood termite (Cryptotermes cynocephalus Light) attacked grown in Dramaga campus Bogor Agricultural University. Sap and hearth woods from nine wood species namely mangium (Acacia mangium Wild), durian (Durio zibethinus), nangka (Arthocarpus heterophyllus), angsana (Pterocarpus indicus), afrika (Maesopsis eminii Engl), rukam (Flacourtia rukam Zoll), trembesi (Samanea saman (Jacquin) Merrill), bisbul (Diospyros discolor Willd), and ki sampang (Evodia latifolia Dc) were used in this experiment. Evaluation of natural durability of wood against termite attacked referred to SNI 01.7207-2006. The results indicated that the weight loss of wood after baited to C.curvignathus and C.cynocephalus were varied among species and positioning wood (sap and hearth woods). It was observed that hearth wood part of nangka wood was the most durable wood against C.curvignathus attacked and it was classified into 2nd class. bisbul, rukam and trembesi woods both sap and hearth wood part and heart wood of angsana wood were classified into 3rd class. mangium and afrika woods both sap and hearth wood parts were classified into 4th class. Ki sampang and durian woods both sap and hearth wood parts and sap wood part of nangka and angsana woods were classified into 5th class. Sap wood part of rukam wood was the most durable wood against C.cynocephalus attacked and it was classified into 2nd class. Bisbul, mangium, ki sampang, afrika, nangka, durian, angsana and trembesi woods both sap and hearth wood parts and heart wood part of rukam wood were classified into 3rd class.
Keyword: hearth wood, sap woodd, subterranean termite, dry wood termite, natural durability

Judul: Preference of Sutterranean Termites to Several Species of Community Wood from Bogor, West Java
Abstrak: Perlu upaya diversifikasi kayu tusam sebagai kayu umpan. Selain itu lama waktu pengumpanan menjadi pertimbangan dalam melakukan pengumpanan. Penelitian ini bertujuan untuk mengevaluasi preferensi rayap tanah terhadap beberapa jenis kayu rakyat dari Bogor dan mengetahui lama waktu terbaik dalam pengumpanan. Kayu yang diuji yaitu Acacia mangium, Paracerianthes falcataria, Anthocephalus cadamba, Maesopsis eminii, Swietenia mahagoni, Hevea brasiliensis, Pinus merkusii. Uji lapang dilakukan berdasarkan American Society for Testing and Material D 1758-06 di Arboretum, Fakultas Kehutanan dan Lingkungan IPB dengan waktu pengumpanan satu sampai enam bulan. Hasil penelitian menunjukkan bahwa, frekuensi serangan rayap pada tapak pengujian sebesar 93,1%. Rata-rata kehilangan berat tertinggi yaitu karet (65,8%) dan terendah yaitu mahoni (7,1%). Semua jenis kayu yang diuji, kecuali mahoni, berpotensi menjadi alternatif umpan rayap. Jenis rayap yang ditemukan adalah Microtermes sp,. Macrotermes sp., Shedorhinotermes sp., dan Capritermes sp., Pine wood requires diversification as bait wood. Also, baiting period is an important consideration for the baiting process. The objectives of this research were to study the termites preference towards several types of community wood from Bogor and to know the best baiting period in baiting process. Wood that has been tested were Acacia mangium, Paracerianthes falcataria, Anthocephalus cadamba, Maesopsis eminii, Swietenia mahagoni, Hevea brasiliensis, and Pinus merkusii. The field tests were carried out according to American Society for Testing and Material D 1758-06 at the Arboretum of Faculty of Forestry and Environment of IPB University with baiting period of one to six month. The results showed that the frequency of termite attacks was 93,1%. The highest average of the weight loss was rubber (65,8%) and the lowest was mahogany (7,1%). All types of wood that have been tested, except mahogany, have the potential to be an alternative for the termite bait. The type of termites found was Macrotermes sp, Microtermes sp., Shedorhinotermes sp., and Capritermes sp.
Keyword: Attack frequency, weight loss, damage intensity, bait period, termite bait

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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