Judul: Akumulasi logam Pb, Cu, dan Zn pada tanaman pelindung di jalur hijau kota Banda Aceh
Abstrak: The city of Banda Aceh planted several types of trees along the roadside as shade and protector, such as Pterocarpus indicus (angsana), Swetenia mahagoni (mahoni), and Polyalthia longifolia (glodogan). These trees were planted also as an effort in solving environmental issues to reduce air pollution. Therefore, the objective of this study was to analyze the concentration of Pb, Cu, and Zn on those three types of trees along the roadside of Banda Aceh, also to evaluate the correlation of the types of tree and the location based on different traffic density. The samples were analyzed for Pb, Cu, and Zn from the leaves, stems, roots, and soils around the trees taken at four locations with different density of traffic. All types of sample were analyzed by Atomic Absorption Spectrometry. Based on the concentration of Pb, Cu, and Zn, the highest accumulation was at location of high traffic density and the lowest at the control sites. For the type of tree, angsana has the highest accumulation of Pb and Zn compared to mahoni and glodogan trees. There were significant correlation for Pb and Cu concentration with accumulation in the soil and the roots, whereas Zn concentration correlated almost with all parts of the trees and its soil.
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Judul: Akumulasi Logam Berat Tembaga (Cu) dan Timbal (Pb) pada Pohon Mangrove (Rhizopora mucronata) di Perairan Karangsong, Indramayu.
Abstrak: Mangrove has many economical and ecological functions, one of its abilities is to absorb, transport and store substances including toxic materials. This research aim is to analyze the concentration of Cu and Pb in root, leave and substrat of mangrove Rhizopora mucronata and its bioaccumulation level. The concentration of Cu found in sediment exceed standar quality by RNO, which means the sediment has been contaminated by Cu. The content of Cu in the roots and leaves of mangrove is greater than Pb, so does the highest level of bioconcentration factor (BCF) was reached by BCF Pb in root at 1.3116 while BCF Cu in roots at 0,5609. This indicates that the potention of accumulation of roots is much higher than the leaves. The highest Translocation Factor (TF) was attained by Pb which is 0.4075 and the lowest is 0.3341 in Cu. Metal translocation from roots to leaves for essential metals (Cu) is lower than in non-essential metals (Pb), it shows that the mangrove use Cu for metabolic activity and growth. The ability of mangrove in accumulating this metals are still low in category according to Concentration Factor Index.
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Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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