Judul: Pemanfaatan Sekam Padi yang Difermentasi Rhizopus oligosporus dalam Pakan terhadap Pertumbuhan Ikan Nila
Abstrak: This research evaluated the effect of rice husk fermented by Rhizopus oligosporus utilization in feed on the growth, feed efficiency and feed digestibility of Nile tilapia (Oreochromis niloticus). The fish with an initial body weight of 10.00 ± 0.01 g were reared for 60 days in aquaria with the size of 100x40x60 cm3. Fish were fed with diets containing fermented rice husk meal at different concentration, i.e. 0%, 2.5%, 5%, 7.5%, and 10%, respectively. The fish were fed to satiation with frequency three times a day. The results showed that utilization of the fermented rice husk in feed did not affect the average weights, feed consumption, fat retention, daily growth rate, survival, and feed efficiency (P > 0.05). However, the utilization of fermented rice husk in feed affected energy digestibility, protein digestibility, and protein retention (P < 0.05). Based on the results, utilization of fermented rice husk in the feed gave the same result. Utilization of rice husk up to 10% was still in the range of optimum because it resulted in similar daily growth rate and feed efficiency as the control of Nile tilapia.
Keyword: rice husk, Rhizopus oligosporus, fermentation, growth, Nile tilapia

Judul: Pemanfaatan Tepung Rumput Laut Rhodymenia Sp. Pada Pakan Ikan Nila Oreochromis Niloticus Sebagai Peningkat Pertumbuhan
Abstrak: Upaya untuk mengurangi bahan baku impor telah banyak dilakukan dengan melakukan penelitian memanfaatkan bahan baku alternatif lokal. Penelitian ini bertujuan untuk menguji pemanfaatan tepung rumput laut Rhodymenia sp. pada pakan ikan nila. Bobot awal rata-rata ikan nila yaitu 4,31±0,004 g/ekor. Perlakuan uji yang digunakan yaitu pemanfaatan Rhodymenia sp. sebesar 0; 2,5; 5; 7,5; dan 10%. Ikan uji dipelihara di dalam akuarium berukuran 50x40x40 cm dengan padat tebar 20 ekor/akuarium. Pemeliharaan ikan nila dilakukan selama 60 hari. Pemberian pakan uji dilakukan menggunakan metode at satiation (sekenyangnya) dengan frekuensi pemberian pakan sebanyak 3 kali pada pukul 08.00, 12.00 dan 16.00 WIB. Hasil penelitian ini menunjukkan bahwa pemanfaatan tepung Rhodymenia sp. sebesar 7,5% memberikan pengaruh berbeda nyata (P<0,05) meningkatkan bobot akhir, jumlah konsumsi pakan, rasio efisiensi protein, retensi protein, laju pertumbuhan harian, pertumbuhan mutlak dan efisiensi pakan. Pemanfaatan tepung Rhodymenia sp. sebanyak 7,5% menghasilkan nilai laju pertumbuhan harian ikan nila sebesar 3,30% dan nilai efisiensi pakan 60,86%.
Keyword: Laju Pertumbuhan, Ikan Nila, Pakan, Rhodymenia sp.

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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