Judul: Kemampuan Penyerapan Timbal pada Pohon Kordia, Angsana dan Mahoni di Hutan Kota Jayakarta PT JIEP, Jakarta Timur.
Abstrak: PT JIEP is one of the three largest industrial Jakarta impaired environmental pollution, especially lead (Pb). Urban forest Jayakarta an urban forest in Pulogadung Industrial Area that is expected to reduce the impact of air pollution through the role of vegetation existing trees in the urban forest. Assessment of the ability of leaves to absorb lead in ambient air using the test method in three species (cordia, angsana, and mahogany) with atomic absorption spectrophotometer (AAS). The results obtained are the leaves that are on the lower canopy and facing the street have the biggest lead content value on each tree. Value absorption largest lead held by leaf cordia because the rough surface hairy leaves but the tree that has the largest value of lead absorption is due angsana tree has leaves that much.
Keyword: absorption of lead, canopy height, leaf morphology, the presence of sources of pollution

Judul: Analisis cadangan karbon pohon pada lanskap hutan kota di DKI Jakarta
Abstrak: In order to reduce enviromental problem, such as air polutions and increasing of air temperature in DKI Jakarta caused the presence of urban forest is very neccessary. Tree has an inportant role becouse its function as store carbon and most efficient carbon sinks in urban areas. Urban forest in DKI Jakarta has problems in development, beside technical aspects are also affected by the goverment policy. The objectives of research were (1) to analyze tree carbon stock, CO2 sequestration and tree species that have potential of carbon, and (2) to analyze policies that support the development of urban forest. The study was conducted at DKI Jakarta, which was focused on tree urban forests, i.e. University Indonesia (Jakarta Selatan), Srengseng (Jakarta Barat) and PT JIEP (Jakarta Timur). The research location was determined by using purposive sampling method, which is based on the representation of the main functions of the urban forest landscape services. Data was collected through survey method. The selection of respondents was conducted by purposive sampling. Sampling plots determination was done by purposive sampling method. Square plot with a size of 20 m x 20 m is used in this research. Determination of tree biomass is done by non-destructive sampling method and tree carbon stocks by using biomass content formula. CO2 uptake values was determined by using the comparative of relative molecular mass CO2 : 3.67 x carbon stocks. Wood density obtained from the database of wood density of trees world agroforestry. Carbon stock analysis was calculated by using allometric equation and urban policy analysis was executed by Analytical Hierarchy Process (AHP) approach. The largest tree carbon stocks were found on UI urban forest was 178.82 ton/ha, Srengseng was 24.04 ton/ha and PT JIEP was 23.64 ton/ha. The largest CO2 uptake generated from UI urban forest was 634.40 ton/ha, Srengseng was 88.15 ton/ha and PT JIEP was 86.76 ton/ha. Factors that affecting the enhancement of carbon stocks, i.e. stem diameter, tree density and the age of the trees. CO2 uptake value resulting from the biggest urban forest UI was 634.40 ton/ha, followed by Srengseng 88.15 ton/ha and PT JIEP 86.76 ton/ha. This information illustrates that in addition for conservation of biodiversity, water uptake and aesthetics landscape, urban forest also has the potential in reducing CO2. Tree of fabaceae family, i.e. Acacia crassicarpa A.Cunn.Ex.Benth, Acacia mangium Willd, Paraserianthes falcataria L, Leucaena leucocephala L, Bauhinia purpurea L, Delonix regia Boj Ex.Hook, Pterocarpus indicus Willd, Erythrina crista-galli L and Abrus precarorius are found that they have biggest contribution for tree carbon stocks in study sites. Policy priorities the supporting the development of urban forest in level factor are increasing of urban forests quality, level actor are government and level alternative are rules evaluation and urban forest expantion.
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Judul: Konstruksi aritmetika kurva eliptik F(2m) supersingular dan non-supersingular untuk skema kunci publik ElGamal
Abstrak: Algoritme ElGamal adalah salah satu algoritme kunci publik dengan aritmetik modular p yang mempunyai struktur grip siklik Z(p). Tingkat keanaman algoritme ini terletak pada pemecahan masalah logaritme diskret dari Z(p). Akan tetapi, tingkat keamanan tadi tahun ke tahun semakin menurun yang disebabkan kemampuan pemecahan algoritme diskret semakin meningkat. Untuk memenuhi tingkat keamanan yang memadai dibutuhkan p yang cukup besar yang menyebabkan proses enkripsi dan dekripsi menjadi lambat.
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