Judul: Daya Rosot Karbondioksida oleh Beberapa Jenis Pohon di Kebun Raya Bogor
Abstrak: One of environment problem nowdays is global warming. Global warming is caused by increasing of temperature in urban area indirectly because increase of Carbon Dioxide (CO2) concentration in the atmosphere. Related on COP 15 about action from result of UNFCCC is to increase CDM system and Copenhagen Accord, then one of effort for decrease CO2 level in urban area is existence of urban forest. Urban forest is CO2 absorbent and has role to control value of CO2, because CO2 is raw material for photosynthesis. The purpose of this research is to determine of sink ability of plant at Bogor Botanical Garden. This research was done at Bogor Botanical Garden for take leaves from ten species and Balai Besar Bioteknologi dan Sumberdaya Genetika Pertanian for analysis of carbohydrate from July until August 2009 at 05.00 WIB; 12.00 WIB; 17.00 WIB; and 20.00 WIB. Tools and materials for this research is plastic, trash bag, camera digital, oven, digital scales, water bath, Cu, Nelson and Carbohydrate reagents, red phenol, aquades, and 10 species (Pterocarpus indicus, Saraca indica, Bauhinia variegata, Brownea hybrida, Eperua falcata, Endertia spectabilis, Dysoxylum cauliflorum, Eusideroxylon zwageri, Neonauclea glabra, dan Bhesa robusta). Mass of CO2 from all species (from 06.00 WIB until 18.00 WIB) are Pterocarpus indicus (14,253 gram), Saraca indica (16,669 gram), Bauhinia variegata (8,238 gram), Brownea hybrida (8,326 gram), Eperua falcata (8,044 gram), Endertia spectabilis (16,581 gram), Dysoxylum cauliflorum (8,479 gram), Eusideroxylon zwageri (15,223 gram), Neonauclea glabra ()15,767 gram, dan Bhesa robusta (9,972 gram). CO2 sink ability influenced by total number of leaves in the plant, then result of sink ability per plant are Pterocarpus indicus (0,456 ton/pohon/tahun), Saraca indica (3,412 ton/pohon/tahun), Bauhinia variegata (0,259 ton/pohon/tahun), Brownea hybrida (1,017 ton/pohon/tahun), Eperua falcata (0,711 ton/pohon/tahun), Endertia spectabilis (1,970 ton/pohon/tahun), Dysoxylum cauliflorum (0,876 ton/pohon/tahun), Eusideroxylon zwageri (31,692 ton/pohon/tahun), Neonauclea glabra (3,460 ton/pohon/tahun), dan Bhesa robusta (1,608 ton/pohon/tahun). Sink ability of all plants consecutive are E.zwageri, N.glabra, S.indica, E.spectabilis, B.robusta, D.cauliflorum, B.hybrida, P.indicus, E.falcata, dan B.variegata.
Keyword: 

Judul: Daya Rosot Beberapa Jenis Pohon Perkotaan terhadap Karbondioksida (CO2) (Studi Kasus di Jalur Hijau Jalan Raya Pajajaran-Bogor)
Abstrak: The global warming happens due to high concentration of certain gasses in the air which are called Green Houses Gasses (GHGs). The global warming is mostly caused by human activities and industries. Carbon dioxide (CO2) is the most important anthropogenic GHGs which caused a variety of activities in both cities moving or not moving as households, hotels, industries, motor vehicles and other activities require driving and heating energy partly derived from the combustion of fossil fuels such as diesel, kerosene and coal. Increased levels of CO2 in the urban air can be overcome with the forest one city. The increment of CO2 concentration in the city can be decreased by implementing urban trees. Carbon dioxide will be absorbed and converted into oxygen through photosynthesis process. The selection of urban trees is needed in order to decrease CO2 effectively. Therefore the study on carbon dioxide sink ability of urban plants should be conducted. The CO2 sink ability of urban trees was measured using carbohydrate method. The carbon dioxide mass was obtained by converting the carbohydrate mass produced from photosynthesis. Other data that were collected consisted of total and width of leaves. More leaves per tree have higher ability of carbon dioxide sink. Wider leaf has higher ability of carbon dioxide sink too. The ability of CO2 sinks from nine species of urban trees is stated in cm2 of leaf width per hour (g CO2/cm2/hour). The result shows that the ability of C. manghas is 8,391 x 10-4; A. mangium is 3,430 x 10-4; S. macrophylla is 2,547 x 10-4; B. purpurea is 2,056 x 10-4; M. calabura is 1,843 x 10-4; F. elastica is 1,466 x 10-4; F. benjamina is 0,787 x 10-4; P. indicus is 0,630 x 10-4; and S. mahagoni is 0,499 x 10-4. It can be concluded that C. manghas, F. elastica and S. macrophylla are the most effective in sinking the CO2.
Keyword: 

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.
Keyword: