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 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: Dynamical System of Hepatitis B in Three Groups with Vaccination
Abstrak: The aim of this study is to modify the hepatitis B transmission model in three age groups involving vaccination from the model conducted by Zhoe and Zhang.The method used is to analyze the stability of the fixed point and its basic reproduction number (R_0). Performed stability analysis and numerical simulation to see population dynamics. Next, a sensitivity analysis of the parameters was carried out to see its effect on R_0. From the analysis obtained two fixed points, namely non-endemic and endemic fixed points. Non-endemic fixed points are locally asymptotically stable if R_0 <1 Meanwhile, the endemic fixed point is locally asymptotically stable if R_0 > 1. Hepatitis vaccination affects the number of susceptible population, because the more successful the vaccination, the smaller the number of susceptible populations so that the smaller the population will be infected.
Keyword: Dynamic, Hepatitis B, Vaccine, Mathematical model