Judul: Kajian Kandungan Logam Berat Timbal (Pb) dan Merkuri (Hg) Pada Air dan Ikan Budidaya Keramba Jaring Apung (KJA) di Waduk Cirata- Jawa Barat
Abstrak: The study was conducted at Cirata reservoir from November 2007 to April 2008. The objective of the study was to analysis timbal (Pb) and mercury (Rg) content both in the water, Common Carp and Oreochromis niloticus liver and flesh and analysis histology. Survey method was used at 3 locations I.e. 1) Citarum basin 2) Cisokan basin and 3) Dangerous zone far floating net cage fish culture activity. Fish~ples were taken from every locations with 3 different age (1, 3 and 5 ) months.The result showed that minimum and maximum values at 2 and 5 m water depth-6for timbal on station two and station one . The minimum values for mercury (Rg) ~n station two and station three and maximum values on station one. Timbal (Pb) ~est concentration inside Common Carp and Oreochromis niloticus liver on statio~ two , where as highest concentration on station three, There are timbal (Pb)inside-xt:'ommon Carp and Oreochromis niloticus flesh, found at the age of disperse 5 mont( with lowest concentration at station two, by concentration 0,00011 mg/kg of Com~n Carp and 0,00016 mg/kg of Oreochromis niloticus body weight respeijively. There are mercury inside Common Carp and Oreochromis niloticus liver!! and 5 months age of disperse, where as mercury not existed in flesh. Age III Influence to timbal concentration Common Carp and Oreochromis niloticus liver at III eve~ station showed significant at level p < 0.05, whereas mercury showed OJ signi~ant of Common Carp liver on station 3. Histological observation showed that there§'-ere necrosis in Common carp and Oreochromis niloticus liver and fish flesh. Keywords :timbal (Pb), mercwy (Hg),water, liverandfishflesh
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Judul: Analisis Kandungan Logam Berat Pb, Cu, dan Cd pada Ikan Nila (Oreochromis niloticus Linnaeus, 1758) Budidaya di Waduk Cirata, Jawa Barat
Abstrak: Waduk Cirata memiliki potensi yang besar baik dalam bidang ekonomi, maupun ekologi. Meskipun begitu, Waduk Cirata sangat rentan terhadap tekanan akibat aktivitas manusia, baik yang berasal dari dalam perairan waduk maupun dari Daerah Aliran Sungai (DAS) Citarum. Penelitian ini bertujuan menentukan kontaminasi kandungan logam berat timbal (Pb), tembaga (Cu) dan kadmium (Cd) pada ikan nila yang dibudidayakan dan hubungannya dengan kualitas perairan di Waduk Cirata. Konsentrasi logam berat dianalisis menggunakan AAS. Kandungan logam berat tertinggi pada ikan nila adalah Cu pada organ ginjal yakni 7,8 mg/kg. Kandungan logam berat tertinggi pada air yaitu Pb yakni 0,210 mg/L. Nilai Bioconcentration Factor (BCF) pada logam Pb sebesar 0,559, Cu 49,166 dan Cd 1,000. Nilai MTI (Maximum Tolerable Intake) untuk orang dewasa (60 kg) pada logam berat Pb sebesar 16,67 kg/minggu, Cd 0,13 kg/minggu dan Cu 11052,63 kg/minggu. Penelitian menunjukkan bahwa kadar Pb, Cu dan Cd tidak sesuai dengan baku mutu yang telah ditetapkan., Cirata Reservoir is great potential both in the economic and ecological fields. However, this Cirata Reservoir is very vulnerable to pressure due to human activities, both from within the reservoir waters and from the Citarum River Watershed (DAS). This study aimed to determine the contamination of the heavy metal content of lead (Pb), copper (Cu) and cadmium (Cd) in cultivated tilapia and its relationship with the quality of waters in the Cirata Reservoir. Heavy metal concentrations were analyzed using AAS. The highest heavy metal content in tilapia is Cu in the kidney, with concentration 7.8 mg/kg. The highest heavy metal content in water is Pb, with concentration 0.210 mg/L. Bioconcentration Factor (BCF) values of Pb 0.559, Cu 49.166 and Cd 1,000. The MTI (Maximum Tolerable Intake) value for adults (60 kg) for heavy metal Pb is 16.67 kg/week, Cd 0.13 kg/week and Cu 11052.63 kg/week. The research shows that the levels of Pb, Cu and Cd are not in accordance with the established quality standards.
Keyword: Cirata reservoir, heavy metals, nile, MTI, tilapia, water

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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