Judul: Pemanfaatan Limbah Pendederan Ikan Lele (Clarias sp.) untuk Pendederan Ikan Nila (Oreochromis niloticus) dan Ikan Gurame (Osphronemus goramy Lac.)
Abstrak: This research was aimed to study the utilization of catfish waste for tilapia and giant goramy in an integrated rearing system. In the research, waste from catfish rearing in cemented tank was utilitized for tilapia (NI) and giant goramy (GI) rearing in an earthen pond as integrated rearing. To compare (as a control) in another earthen pond, tilapia (NK) and giant goramy (GK) were reared and fed with artificial feed. Catfish, tilapia and giant goramy stocking density was 2000 fish/m3, 24 fish/m2, 10 fish/m2 respectively. Catfish, tilapia and giant goramy which used had been measured and each size were 0.94 g, 1.21 g, and 0.22 g. The research showed that The wastes produced by the catfish biomass of 644.67 g/m2 at initial and 1399.58 g/m2 at harvest could be used to grow tilapia and giant goramy. Until day 22 fish size remains the same at integrated rearing system and control, while at day 28, the growth rate of NI 1.92% lower than NK, whereas the GI lower 0.78% compared to GK. Survival rate of NI was 6.03% lower than NK, while GI was 0.51% lower than GK.
Keyword: giant goramy., tilapia, growth, utilization, waste

Judul: Penggunaan Destillers Dried Grain with Solubles (DDGS) Jagung sebagai Sumber Protein Nabati Pakan Benih Ikan Gurame Osphronemus gouramy Lac.
Abstrak: This experiment was conducted to examine the effect of the use of DDGS as a source of vegetable protein on the growth of the giant gouramy O. gouramy Lac. juvenile. Feed is devided into two, the feed for testing of digestibility and testing of growth. The feed for testing of digestibility are References Diet (100% control of feed) and Test Diet (70% of control feed and 30% of DDGS), while the feed for testing of growth are 0%, 10%, 20%, and 30% DDGS. The fish were feed the experimental diet at satiation. Giant gouramy be used in this research have weight 4.72±0.78 g. Culture of fish conducted during 40 days in the aquarium sized 50x40x35 cm. Test of growth from DDGS up to 30% showed no significant difference (P>0.05) in daily growth rate (2.82 to 2.91%), survival rate (100%), feed consumptions (139.07-159.22 g), and feed efficiency (64.52-71.05%). Whereas, protein retention (16.29 to 25.02%), lipid retention (31.36 to 53.52%) are significantly different with control. It is conclude that the use of DDGS as the source of vegetable protein with various consentration on the feed of giant gouramy until 30% didn’t affect the daily growth rate, survival rate, and feed consumptions. The highest feed efficiency of DDGS treatment is 20%.
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Judul: Bifurkasi lokal pada titik tetap non-hiperbolik
Abstrak: Bifurkasi menggambarkan perubahan pada struktur orbit di sekitar titik tetap. Titik tetap dibagi menjadi dua yaitu titik tetap hiperbolik dan titik tetap non-hiperbolik. Titik tetap non-hiperbolik terjadi jika ada nilai eigen dengan bagian real sama dengan nol. Kestabilan dari titik tetap dapat diketahui dari nilai eigen yang diperoleh dari pelinearan medan vektor. Pada bifurkasi satu-dimensi ditemukan kasus-kasus untuk bifurkasi saddle-node, bifurkasi transcritical dan bifurkasi pitchfork. Bifurkasi saddle-node terjadi jika satu sisi dari nilai parameter tidak terdapat titik tetap dan pada sisi lain terdapat dua titik tetap, dimana yang satu stabil dan yang lainnya tak-stabil. Bifurkasi transcritical terjadi jika terdapat pertukaran kestabilan, yaitu dari titik tetap stabil menjadi titik tetap tak-stabil dan sebaliknya. Sedangkan bifurkasi pitchfork dibagi menjadi dua, yaitu: bifurkasi pitchfork supercritical dan bifurkasi pitchfork subcritical. Bifurkasi pitchfork supercritical terjadi jika satu titik tetap stabil berubah menjadi dua titik tetap stabil dan satu titik tetap tak-stabil, dan bifurkasi pitchfork subcritical terjadi jika satu titik tetap stabil dan dua titik tetap tak-stabil berubah menjadi satu titik tetap tak-stabil. Bifurkasi Hopf (bifurkasi dua-dimensi) terjadi jika terdapat orbit periodik pada struktur orbitnya yang berupa lingkaran dengan jari-jari konstan. Ada atau tidaknya orbit periodik dapat diketahui setelah sistem ditransformasikan ke dalam koordinat polar. Orbit periodik ini dapat bersifat stabil maupun tak-stabil. Model periklanan (advertising) Feichtinger merupakan salah satu contoh penerapan bifurkasi Hopf Model ini menghasilkan satu titik tetap dan orbit periodik yang bersifat stabil.
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