Judul: Kualitas media budidaya dan produksi ikan lele sangkuriang Clarias sp. yang dipelihara pada sistem resirkulasi dengan kepadatan berbeda.
Abstrak: Increasing demand for catfish and the need of anticipation for aquaculture productionadecreasedaasaresultafromashrinkageaofacultivatedaland and deturatio n water quality in catfish media causes catfish cultivation should be done intensively by through improvement of culturing technology, one of them is throught utilization of a recirculation system in order to maintain water quality. Therefore, this experiment will observe at changes of water quality that occur in catfish rearingnponds at different stockingadensity whichausinga recirculation system. The purpose of this experiment was to analyze the changes in water quality, growth, survival and differences in the production growth of Sangkuriang catfish Clarias sp. in the outdoor recirculation system with different stocking density as a base for determining the optimal stocking density. The experimentawasaimplementedafromaAugustato Septembera2011,aatathe Installati on ofaAquacultureaEnvironmental Research and Toxicology, Cibalagung, Bogor. The design of the experiment is Randomized Complete Design with 3 treatments and 3 replications. The treatments include 50 ekor/m2, 100 ekor/m2 dan 150 ekor/m2. Water quality measurements performed on a regular basis, consisting of physical and chemical character of maintenance water media that ware temperature, pH, DO, ammonia, nitrites and nitrates as well as measurement fish biology parameters include, SR, SGR, the absolute growth weight and length. The results showed that different stocking density that used in each treatment produces changes of water quality still within the normal range for rearing Sangkuriang catfish Clarias sp . The treatment that gives the growth, survival and production results of best is the 150 ekor/
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Judul: Performance of nursery production Sangkuriang catfish Clarias sp. at stocking density 35, 40, 45 dan 50 fish/litre in medium height of 30 cm.
Abstrak: Ikan lele merupakan komoditas yang memiliki prospek pasar yang cerah dan dapat dipelihara dengan kepadatan tinggi. Penelitian ini bertujuan untuk menentukan padat tebar yang optimal dan efisien diantara 35, 40, 45, dan 50 ekor/liter pada produksi benih lele ukuran 2-3 cm dengan ketinggian air 30 cm melalui kajian parameter biologi, kualitas air dan ekonomi. Penelitian ini meliputi tahap persiapan, rancangan percobaan, pemeliharaan ikan, pengamatan dan analisi data. Ikan yang digunakan adalah benih lele Sangkuriang dengan panjang rata-rata 0,77±0,03 cm dan bobot rata-rata 0,003±0,001 gram. Benih dipelihara dengan padat penebaran yang berbeda. Tahap pemeliharaan dan pengumpulan data dilakukan dengan mengamati kelangsungan hidup ikan dan mengamati pertumbuhan ikan selama 20 hari. Hasil penelitian menunjukkan padat penebaran 45 ekor/liter merupakan padat penebaran yang optimal dengan derajat kelangsungan hidup (SR) sebesar 82,57±3,66%; laju pertumbuhan spesifik (SGR) sebesar 21,33±1,15%; pertumbuhan bobot harian (GR) sebesar 0,0062±0,0015 gram/hari; yield sebesar 11,60±2,23 gram/hari; pertumbuhan panjang mutlak sebesar 1,17±0,06 cm; nilai koefisien keragaman panjang sebesar 9,30±1,05%; nilai feed convertion rates (FCR) sebesar 1,94±0,35; keuntungan senilai Rp2.945.772; R/C senilai 1,20. BEPp sebesar Rp 15.031.828; BEPu sebesar 207.933 ekor; serta payback period selama 31 bulan. Perbedaan padat penebaran tidak berpengaruh nyata terhadap GR, pertumbuhan panjang mutlak dan FCR. Namun berpengaruh nyata terhadap SR, yield, dan koefisien keragaman panjang. Kualitas air selama percobaan masih berada dalam kisaran optimum bagi pertumbuhan benih ikan lele Sangkuriang. Pendederan ikan lele sebaiknya dilakukan pada ketinggian air 30 cm dengan kepadatan ikan 45 ekor/liter yang dipelihara dalam lingkungan yang baik dan pakan yang tercukupi.
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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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