Judul: Pertumbuhan ikan nila BEST Oreochromis sp. dalam budidaya sistem akuaponik dengan waktu tinggal aliran air yang berbeda
Abstrak: Intensive culture of BEST tilapia does not only produce fish biomass but also waste. The waste are usually managed to avoid its toxic which can hamper fish growth, and even, cause death of fish. One of the management activity is application aquaponic as a culture system. The purpose of the study was to determine water flow detention time in the hydroponic chamber to achieve optimal growth and production of the fish in the aquaponic culturing system. The water flow treatment consisted of 3 level of detention time, is 30, 60, and 120 minutes. Another treatment was culturing the tilapia in a flow through culturing system as a control. During 40 days culturing periode, the highest daily individual, biomass and length growth rate up to 0.54 g/day, 369.58 g/day and 5.58 cm respectively (P<0.05). While survival rate of the fish was at the range of 64.50-80.80%, feed conversion rate was 1.24-1.33 (P>0.05). The result showed that the detention time affected individual, biomass and length growth rate of the fish, in which the highest value reached by the detention time of 120 minutes. While survival rate and feed conversion rate were not affected by the different detention time treatments. The aquaponic system could remove total N and P up to 10.69 % and 38.10% respectively. The 120 minutes detention time treatment resulted in the highest economic benefit.
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Judul: Kinerja Pertumbuhan Ikan Nila Oreochromis niloticus Strain BEST pada Media Pemeliharaan dengan Derajat Kemasaman Berbeda
Abstrak: In Indonesia, peat land has pH degree that is relatively high, ranged from 3-5. Tilapia which is one of the superior commodities, is expected to be introduced in peat land as well as conducted with catfish. In order that, the production of tilapia is able to be improved optimally in more aquaculture lands of Indonesia. The objective of this study is analyze the work of growth in BEST tilapia strain, include Survival Rate, Specific Growth Rate, the growth of absolute length, amount of feed consumtion, feed efficiency, rearing media with acidity degree 3, 4, 5, and 6. Tilapia strain BEST that are used in the study size from 4,52±3,9 cm long and 1,35±0,3 g weight. The tilapias were placed in 12 aquariums with 60x50x40 cm in size and density as many as 40 fish each. The feed is the made-up feed (pellet) and given 3 times a day at satiation. Based on the result of this research, at 3 and 4 acidity degree the BEST strain tilapia couldn’t survive, showed by 0 % of survival rate. At 5 acidity degree, the survival rate was 50,8% whereas at 6 acidity degree was 75%. Growth rate either length growth and Specific Growth Rate at 5 acidity degree was slower than 6 acidity degree. Besides the acidity degree treatment on media could caused damaged in gill microanatomy include the damage such as hypertrophy, hyperplasia, fuse and telangiektasis with diffrent level of damage.
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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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