Judul: Utilization of kolong for aquaculture: use of compost to minimize concentration of lead (Pb) in fish culture media
Abstrak: Danau bekas galian timah atau kolong yang berusia muda banyak terdapat di Kepulauan Bangka Belitung. Kolong-kolong ini memiliki potensi untuk dimanfaatkan bagi kegiatan akuakultur. Namun permasalahan utama yang dihadapi yaitu pH air yang rendah dan tingginya kandungan logam berat di air. Timah hitam (Pb) merupakan salahsatu logam berat berbahaya yang terdapat di air kolong. Logam ini merupakan mineral non esensial yang sama sekali tidak dibutuhkan oleh tubuh. Air yang mengandung logam berat Pb tentunya tidak layak digunakan untuk budidaya ikan. Oleh karena itu perlu dilakukan treatment terhadap air agar air layak digunakan untuk budidaya ikan. Kompos merupakan salahsatu bahan yang dapat digunakan untuk meminimalisasi logam berat Pb di air. Kandungan substansi humus, seperti : asam humat, asam fulvat dan humin yang jumlahnya dominan merupakan substansi yang berperan dalam proses minimalisasi. Selain itu kandungan mineral yang terdapat pada kompos walaupun jumlahnya tidak dominan dapat mengalami pertukaran dengan ion Pb. Proses minimalisasi logam Pb di air terjadi melalui pertukaran kation, ikatan elektrostatik, pementukan senyawa kompleks dan chelate.
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Judul: Analisis Bioakumulasi Timbal (Pb) Pada Ikan Nila Merah (Oreochromis nilotica) dan Patin Jambal (Pangasius djambal) yang Dibudidayakan di Kolong Tua pasca Tambang Timah Bangka Belitung
Abstrak: The consequences of tin mining activity is the formation large basin-shaped holes filled with water in which the local (Bangka Belitung islands) term is a Kolong or Camuy (lake). Heavy metal concentrations are still high in all the pit and endangering human health; is the image that is in today's society so that people refused to eat the fish from or doing aquaculture activities in kolong. The study was conducted from October 2011 to February 2012 in Kolong Grasi, District Sungailiat Bangka Regency, Province of Bangka Belitung Archipelago at coordinates S01052.464 '; E106007.005. Chemical analysis carried out at the Laboratory of Industrial Technology of Agricultural, Aquaculture Environmental Laboratory, Fish Nutrition Laboratory, IPB. Materials used in this study are meats, gills, liver and kidneys of red tilapia and jambal catfish. Organ samples taken each month from October 2011 to February 2012. Chemicals for testing heavy metal Pb is the standard solution at a concentration of 1000ppm Pb from BDH, concentrated nitric acid from Merck and distilled water. The equipment used is the pH meter, DO meter, analytical neraca, a ruler, a set of surgical instruments, two units of floating net cage with the dimension 3m x 3m x 2m of each, and pH-meters, a set of Atomic Absorption Spectrometry tools (AAS) AA 300 P type from Varian Techtron Australia, 50ml beaker glass, 10 ml volumetric flask, 5ml vial size polyethylene, 10-100mL effendorf micro pipettes, analytical balance, furnace, hot plate, Mercury Vaporise Unit (MVU) and other glassware equipment used in labs. The study began with measurements of heavy metals lead (Pb) in water and sediment once at the beginning of the study. Measurement of water quality include physical parameters are: temperature, pH, brightness, and chemical parameters including DO, CO2. Measurements were made directly in the field. Measurement of chemical parameters such as: Total Organic Matter (TOM) and Pb performed in the laboratory at the beginning of the fish culture period and then performed each month at the site of cultivation. Measurement of Pb content in the sediment is also done once in the early of the study. All data was analyzed using the comparison of two mean values (t-test). The results of gut contents identification of fish are presented in tabulated and all the relationships described in the descriptive parameters. Physico-chemical quality of water in Kolong Grasi is ideal for red tilapia aquaculture and jambal catfish. Several parameters such as temperature, brightness decreased and increased levels of TOM in January 2012 and did not occur in previous months dueto the rainy season in January 2012. Pb heavy metal content in the red tilapia was found in the first month of cultivation, the month of November is 0,085μg/g in liver. In the third month (January 2012), lead is found in almost every organ of red tilapia and exceed safe levels for consumption, ie 8,41 μg/g in the gills, 93,98 μg/g in kidney, 62,14 μg/g in the liver and undetectable in meat. Accumulation of the heavy metal in the meat of red tilapia is found 0,188 μg/g in the mont of fourth (February 2012). The highest
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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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