Judul: Keanekaragaman Oxydothis Penz. & Sacc. (Fungi, Xylariales) pada Palem-paleman (Arecaceae) di Kebun Raya Bogor
Abstrak: Palm (Arecaceae) is monocotyledonous plant and widely distributed worldwide. Oxydothis Penz. & Sacc. is a fungal genus belonging to phylum Ascomycota. Bogor Botanical Garden (KRB) is well-known as one of important ex-situ conservation of tropical plants, especially in Indonesia. This study was aimed at examining the diversity of Oxydothis associated with palms in KRB. Decaying fronds from Arecaceae sites with black, gray, or brown spot on the surface were collected. Asci, ascal ring, and ascospores were observed in shears medium, and Melzer reagent was used to see the amyloid reaction of ascal ring. A total 16 species were identified as follow: O. angustispora J. Fröhl. & K.D. Hyde, O. asymmetrica J. Fröhl. & K.D. Hyde, O. batuapoiensis J. Fröhl. & K.D. Hyde, O. belalongensis J. Fröhl. & K.D. Hyde, O. daemonoropsicola J. Fröhl. & K.D. Hyde, O. dispariapicis J. Fröhl. & K.D. Hyde, O. elaeicola Petr., O. extensa J. Fröhl. & K.D. Hyde, O. grisea Penz. & Sacc., O. hoehnelii (Rehm.) Sacc., O. hongkongensis J. Fröhl. & K.D. Hyde, O. licualicola J. Fröhl. & K.D. Hyde, O. nonspecifica J. Fröhl. & K.D. Hyde, O. rattanica J. Fröhl. & K.D. Hyde., O. rattanicola J. Fröhl. & K.D. Hyde, and O. rimicolla J. Fröhl. & K.D. Hyde.
Keyword: Arecaceae, Ascomycota, diversity, Bogor Botanical Garden, Xylariales

Judul: Studi Keanekaragaman dan Penyebaran Spasial Palem-Paleman (Arecaceae) di Hutan Lindung Gunung Slamet, Baturaden – Provinsi Jawa Tengah
Abstrak: Palm is one of interesting plant. It has been used for several needs and also a trading commodity. One of palms habitat is in Protected Forest of Mount Slamet. The threat of land conversion and forest fires is a problem in this area. The lack of information on the diversity, abundance and the distribution of palms make this area vulnerable and increated the possibility of unknown palms to go extinct. The purpose of the research is to describe the composition, diversity and the ecological distribution of palms and also analyzing the distribution of palms based on land and altitude. Research was conducted on May until June 2012, on two type of ecosystems natural forest and mix forest at Protected Forests of Mount Slamet. Data were collected using vegetation analysis method. Data of the palms were analyzed to obtain value of diversity, evenness and abundance of species. Spatial distribution Data were obtained from recording palms position. Thematic map of land and altitude was developed on processing the landsat map and divided them to different classes. Then, it was overlayed with palms point of occurence to produce a map of palms distribution based on land and altitude. Composition of palms on Protected Forests of Mount Slamet, on natural forest ecosystem found 12 species, and on mix forest ecosystem found 6 species. Distribution pattern of palms is clumped. The higest diversity of palms occurs on natural forest at 1.200 mdpl-1.300 mdpl with elevation 8-15 %, and mix forest at 900-1.000 mdpl with elevation 8-15%.
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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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