Judul: Kandungan Logam Berat Pb dan Cd pada Sedimen di Waduk Saguling, Bandung, Jawa Barat
Abstrak: Saguling Reservoir is a reservoir that received water flow from the Citarum River, which was pouled by many industrial wastes. These wastes contain heavy metals such as Pb and Cd that contaminated water, sediment and biota in the reservoir. The observation on the sediment, is expected to give a results about nominal level of the heavy metal pollution in that reservoir. The result showed that the content of heavy metal Pb and Cd was 8.623 ppm and 0.721 ppm. The value of both heavy metals at each station states that the levels of heavy metal pollution in sediments has exceeded the standard quality by EPA (1987) in the Laws (1993). In comparison with the content of heavy metals in water, sediment has a greater concentration with an average ratio of 11:1. Whereas v sediment in comparison with the content of heavy metals in Tutut, they have a smaller concentration values with an average ratio of 0.4:1. Distribution value of the heavy metal Pb and Cd in Saguling Reservoir have the same pattern, is high in inlet, and then decrease in the middle and increase surpass the inlet. The recommended supervision to reduce waste pollution in Saguling, is the implementation of the waste water treatment (IPAL) to industries that dispose their wastes to the water.
Keyword: Saguling Reservoir, Heavy metals, Pollution

Judul: Evaluasi Kontaminasi Logam di Sedimen Dari Waduk Saguling Dengan Menggunakan Konsep Triad: Sebuah Pendekatan Dalam Pengelolaan Waduk
Abstrak: Saguling reservoir was cascade type reservoir that located in West Java, the reservoir have gotten degradation problem of water quality as result of organic, pesticide, and heavy metal pollution coming from antropogenic activity and also naturally. Existence of heavy metal in aquatic area has tendency for binding with particulate material as sediment compiler and has potency for bioavailable for aquatic biota. Therefore its required a research which integrated to express level of metal bioavailability which bound at sediment like ioning triad concept ( combine information from chemical analysis, community structure, and toxicity test). This research has been done in the year 2006 with aim to predict level of metal bioavailability Cu, Cd, Pb, and Hg in sediment using triad concept approach. Sediment Heavy metal contamination Result in each station showed heavy significant differences for Cd ( F= 17,803 and p = 0,00001), Pb ( F= 154,343 and p < 0,01), Cu ( F= 36,499, P<0,000001), and Hg ( F= 12,49 and p=0,00000). Elevation of Heavy metal contamination in sediemet usually is followed with disturbance of community structure for benthic macroinvertebrate and increasing of sediment toxicity status (Maroko, Cihaur, Cangkorah, Batujajar, and Nanjung station). At the others station existence of benthic macroinvertebrate community disturbance and height of sediment toxicity were caused by other factor besides heavy metal. Combined Result between triad radar graphs and multivariate analysis (PCA) indicated Cu, Hg, and Pb that have bioavailable potency in Saguling Reservoir. Statistically Cd has not enough evidence generating Hydra toxicity and disturbance of benthic macroinvertebrates community. Result of this research is a strategy to study bioavailability pollutant which binding in sediment for managing reservoir caused by exposure toxic materials in aquatic environment.
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Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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