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: Efektivitas Penggunaan Sekam Padi yang Difermentasi Trichoderma reesei dalam Pakan terhadap Pertumbuhan Ikan Nila
Abstrak: Penelitian ini mengevaluasi efektivitas tingkat penggunaan sekam padi yang difimentasi Trichoderma reesei dalam pakan terhadap pertumbuhan, efisiensi, dan kecemaan pakan pada ikan nila (Oreochromis niloticus). Ikan nila dengan bobot rata-rata 6,58±0,01 gram dipelihara dalam akuariian berukuran 60x50x40 cm³ yang dilengkapi sistem resirkulasi selama 60 hari. Ikan uji diberi lima jenis pakan yang mengandung sekam padi difermentasi T. ressei sebagai pengganti dedak halus masing-masing sebesar 0%, 2,5%, 5%, 7,5%, dan 10%. Pemberian pakan dilakukan secara at satiation sebanyak tiga kah sehari Hasil penelitian menunjukkan bahwa mai efisiensi pakan dan retensi lemak dari setiap perlakuan tidak berbeda nyata. Peningkatan mai kecemaan protein, kecemaan energi, dan retensi protein tertinggi ditunjukkan pada pakan yang mengandung sekam padi fermentasi sebesar 7,5% yaitu secara bertaut-turut 88,71±0,23%, 82,29±0,43%, dan 21,21±0,60% Penambahan sekam padi fermentasi 7,5% pada pakan juga meningkatkan laju pertumbuhan harian ikan nila yaitu sebesar 2,17±0,07%. Dengan demikian, penggunaan sekam padi fermentasi 7,5% efektif untuk pertumbuhan ikan mla….
Keyword: Growth, Oreochromis niloticus, rice husk, Trichoderma reesei, Feed efficiency, Nile tilapia, Digestibility, Fish feeding, Recirculation system, Satiation method

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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