Judul: Produksi Benih Gurami Osphronemus gouramy Lac. Ukuran 4 cm pada Padat Penebaran 20 ekor/ℓ dengan Pergantian Air 75 %, 100 % dan 125 % Per Hari
Abstrak: Water exchange is needed to maintain water quality especially in aquarium with high stocking density to support growth and survival of fish. The research was conducted between March 2010 until May 2010 at the Laboratory of Aquaculture Technology and Management Department of Aquaculture, Faculty of Fisheries and Marine Science, Bogor Agricultural University. Giant gouramy seed with initial average size of 2.07+0.16 cm in length and 0.28+0.006 g in weightderived from the Cibeureum, Dramaga, Bogor, West Java was used as the experimental animal. Containers used for fish rearing were 9 aquaria sized 60x29x33 cm3 which filled with 35 liters of freshwater. The fish was fed at satiation with oligochaetes worm twice daily. The water is replaced every day according to the treatment. The results showed that as the percentage of water replacement increases the fish survival, growth and feed efficiency increase. The 125% water exchange resulted in the best profit and economy efficiency which was whown by the lowest unit cost (Rp407,30) and the highest R/C ratio (1,76). The water quality parameters showed that it was still in an optimum range for the growth and development of giant gouramy seed.
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Judul: Produksi benih Gurami (Osphronemus gouramy Lac.) ukuran 2 cm pada padat penebaran 20 ekor/L dengan pergantian air 75 persen, 100 persen dan 125 persen dari total volume air
Abstrak: Giant gouramy Osphronemus gouramy Lac. is one of the most important fresh water fish commodities with increasing production level every year. Water quality management through a proper water exchange both in quantity and quality can be one of the alternatives to support the elevating production. This research was conducted from July to August 2010 at the Aquaculture Production Technology and Management Laboratory, Department of Aquaculture, Faculty of Fisheries and Marine Science, Bogor Agricultural University. The seed used was 0.84+0.011 cm in length and 0.017+0.001 cm in weight which reared in 9 units of aquaria with a size of 60x29x33cm3. Silk worm was used as the feed and provided daily at satiation . Water exchange was performed twice a day at a level depending on the treatment, namely 75% (50% at morning and 25% at evening), 100% (50% at morning and evening) and 125% (75% at morning and 50% at evening) of total water volume. Water exchange at 75%, 100% and 125% per day resulted in survival rates of 94.11+0.63%; 91.89+2.02%; and 93.89+0.75%; specific growth rates of 7.43+0.15 %, 8.58+0.24 %, and 9.97+0.18 %. Growth rate in length of 1.06+0.06 cm, 1.33+0.04 cm, and 1.55+0.01 cm; coefficient of variation in length of 11.31+1.43%, 9.35+1.46%, and 6.90+2.30%; feed efficiency of 12.47+0.30%, 14.32+1.05%, and 19.67+0.54%. the financial benefits resulted of the process were worth of IDR.351,903.00; IDR.402,302.00; and IDR.464,715.00; whereas R/C ratio of 1.71; 1.80; dan 1.90; BEP of 1,845 unit, 1,645 unit, and 1,517 unit; payback period (PP) of 0.97 years, 0.85 years, and 0.74 years; and the cost production as much as IDR.79.90; IDR.82.70; and IDR.82.90 per individual, respectively. The treatments were significantly different on several parameters, such as specific growth rate, length of growth rate, feed efficiency at P<0.05. The results of this experiment showed that 125% daily water exchange improved the production performance of giant gouramy seed cultured at a density of 20 fish/L. For production purpose, rearing giant gouramy fish 2 cm in size at a density of 20 fish/liter was found as the optimum condition through 125%/day water exchange.
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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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