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: Produksi Pendederan Benih Gurami Osphronemus gouramy Lac. Ukuran 6 cm pada Padat Penebaran 2, 3, 4 dan 5 ekor/liter
Abstrak: Penelitian ini bertujuan untuk menganalisis kinerja produksi pendederan benih gurami Osphronemus gouramy Lac. ukuran 6 cm dengan padat penebaran 2, 3, 4 dan 5 ekor/liter yang dipelihara di akuarium. Penelitian ini dilaksanakan pada bulan Juli 2009 sampai dengan bulan September 2009 bertempat di Laboratorium Sistem Produksi dan Manajemen Akuakultur, Departemen Budidaya Perairan, Fakultas Perikanan dan Ilmu Kelautan, Institut Pertanian Bogor. Ikan uji yang digunakan adalah benih ikan gurami dengan panjang rata-rata 4,01±0,20 cm dan bobot rata-rata 1,99±0,40 gram yang dipelihara dalam akuarium selama masa pemeliharaan 35 hari. Rancangan percobaan yang digunakan adalah Rancangan Acak Lengkap (RAL) yang terdiri dari 4 perlakuan yaitu padat tebar 2, 3, 4 dan 5 ekor/liter serta 3 kali ulangan. Setiap akuarium diisi air sebanyak 10 liter. Ikan diberi pakan komersil tiga kali sehari berupa pelet berdiameter 1 mm dengan kadar protein 38-39% dengan jumlah pemberian per hari 6% dari biomassa ikan. Setiap hari dilakukan penyifonan kotoran pada dasar akuarium dan pergantian air 75% dari total volume air pemeliharaan. Suhu dipertahankan 290C dan aerasi di dalam air dijalankan terus menerus. Hasil penelitian menunjukkan bahwa peningkatan padat penebaran dari 2 hingga 5 ekor/liter memberikan pengaruh yang berbeda terhadap derajat kelangsungan hidup, laju pertumbuhan bobot harian, pertumbuhan panjang mutlak, koefisien keragaman panjang dan efisiensi pakan. Pada padat tebar 2, 3, 4 dan 5 ekor/l diperoleh derajat kelangsungan hidup berturut-turut sebesar 100%, 88,89%, 80,83%, 69,33%; laju pertumbuhan bobot harian sebesar 4,05%, 3,93%, 3,76%, 3,46%; pertumbuhan panjang mutlak sebesar 2,01 cm, 1,86 cm, 1,78 cm, 1,51 cm; nilai koefisien keragaman panjang sebesar 3,04%, 3,45%, 8,36%, 10,66%; serta efisiensi pakan sebesar 76,52%, 69,20%, 61,36%, 48,40%. Perhitungan efisiensi ekonomi tertinggi dalam skala produksi 6400 liter/tahun diperoleh pada perlakuan 4 ekor/liter dengan keuntungan sebesar Rp. 4.279.956; R/C 1,26; PP 0,90 tahun dan biaya produksi per ekor sebesar Rp 793. Pada penelitian ini secara umum kualitas air yang diperoleh masih berada dalam kisaran optimum bagi pertumbuhan dan perkembangan benih ikan gurami. Untuk tujuan produksi pendederan benih ikan gurami ukuran 6 cm sebaiknya dilakukan dengan padat penebaran 4 ekor/liter.
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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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