Judul: Analisis Biomassa dan Kandungan Karbon pada Jenis Serasah Daun Tanaman Hutan Kota di Arboretum Arsitektur Lanskap IPB, Bogor
Abstrak: Urban forest functioned as oxygen balancing (O2) and carbon dioxide (CO2), reduce pollutant, stored and emission carbon. This research aimed to measured biomass, carbon dioxide content, connection between biomass and binding carbon, and measured carbon dioxide absorption ability on manure type of city Forest plant on Arboretum Architecture Landscape IPB, Bogor. Method used in this research was destructive method during 7 weeks to 7 types of city plants were : trembesi (Samana saman), merbau (Intsia bijuga), dahu (Deacontomelon dao),ki putri (Podocarpus neriifolius), kayu manis (Cinnamonum zeylanicum), nangka (Artocarpus heterophylus), simpur (Dillenia indica). Trembesi (Samanea saman) and merbau (Intsia bijuga) was such type that has both highest binding biomass and carbon from seven type of city forest plants. Besides that leaf manure type from trembesi (Samanea saman) and merbau (Intsia bijuga) that have highest ability to absorb CO2 about 4.749 and 4.007 ton/ha/year. Urban forest development by plant both trembesi and timber tree types were as one alternative to reduce increasingly emission of carbon.
Keyword: urban forest., carbon content, biomass

Judul: Daya Rosot Karbondioksida Oleh Beberapa Jenis Tanaman Hutan Kota di Kampus IPB Darmaga
Abstrak: The increase of temperature in urban area is indirectly caused by the increase of Carbon Dioxide (CO2) concentration in the atmosphere. The increase is caused by land cover alteration and high amount of human activities which uses fossil fuel. The existence of urban forest is one of the ways to coupe the increase of CO2 concentration in the urban atmosphere. Through photosynthesis process, CO2 gas is absorbed by various plants in urban forest and afterwards being released as Oxygen (O2). To control or reduce the concentration of CO2 effectively, in the establishment of urban forest, selection of plants which have maximum ability in reducing CO2 concentration needs to be done. The objectives of this research are to obtain data CO2 sink ability of 15 urban forest plant species in Bogor Agricultural University and to obtain data about the plant species that has the effective CO2 sink ability among the plants which are measured. The measuring of CO2 sink ability was conducted using carbohydrate method. CO2 mass is obtained by converting carbohydrate mass produced in photosynthesis. Other data taken include leaf area and the number of leaves. The higher the leaf area, the higher CO2 sink ability of a leaf. The higher number leaf of a tree, the higher CO2 sink in a tree. The CO2 sink ability of 15 plant species in cm2 of leaf area are (g CO2/cm2/hour): M. caesia 3,793 x 10-4; D. indica 2,180 x 10-4; B. racemosa 1,600 x 10-4; S. campanulata 1,249 x 10-4; M. champaca 1,176 x 10-4; S. malacense 0,820 x 10-4 ; B. capitella 0,805 x 10-4; C. cauliflora 0,734 x 10-4; V. pubescens 0,669 x 10-4; C. inophyllum 0,629 x 10-4 ; M. ferrea 0,479 x 10-4; A. moluccana 0,357 x 10-4; A. dammara 0,268 x 10-4-; and G. dulcis 0,089 x 10-4. The CO2 sink ability of 15 plant species in urban forest in order from the highest are D. indica, M. caesia, S. campanulata, C. inophyllum, B. racemosa, V. pubescens, M. ferrea, C. cauliflora,B. capitella, G. dulcis, M. champaca, S. malacense, A. moluccana, and A. dammara. Keywords: carbon dioxide sink, urban forest.
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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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