Judul: Efektivitas Penambahan Asam Amino Bebas pada Pakan terhadap Kinerja Pertumbuhan Benih Ikan Nila Merah Oreochromis niloticus.
Abstrak: Penelitian ini bertujuan untuk menentukan efektivitas asam amino bebas glutamina, glutamat dan monosodium glutamat (MSG) dalam meningkatkan kinerja pertumbuhan ikan nila Oreochromis niloticus. Rancangan yang digunakan dalam penelitian ini adalah rancangan acak lengkap (RAL) dengan empat perlakuan penambahan asam amino bebas, yaitu glisina 3%, glutamina 3%, glutamat 3%, dan MSG 3% dengan masing-masing terdiri dari tiga ulangan. Ikan yang digunakan adalah benih ikan nila merah berukuran 0.30 ± 0.08 g yang ditebar ke dalam 12 akuarium kaca (100 x 45 x 45 cm) dengan padat tebar 30 ekor ikan/ akuarium dan dipelihara selama 40 hari. Berdasarkan hasil penelitian didapatkan bahwa nilai bobot akhir, tingkat kelangsungan hidup, jumlah konsumsi pakan, efisiensi pakan, laju pertumbuhan harian, dan retensi protein tidak berbeda nyata antar perlakuan. Sedangkan pada rasio panjang usus/ panjang tubuh terbaik terdapat pada perlakuan dengan penambahan glutamina dan glutamat.
Keyword: asam amino bebas, glutamina, glutamat, nila merah

Judul: Efektivitas Penambahan Glutamin dan Glutamat dalam Pakan untuk Kinerja Pertumbuhan Benih Ikan Nila Merah Oreochromis niloticus
Abstrak: Penelitian ini bertujuan untuk mengevaluasi efektivitas penambahan glutamin dan glutamat dalam pakan terhadap kinerja pertumbuhan benih ikan nila merah Oreochromis niloticus. Penelitian ini terdiri atas lima perlakuan pakan dengan tiga ulangan, meliputi pakan dengan penambahan glisin 3% sebagai kontrol, dan 4 jenis pakan dengan penambahan 3% glutamin, 1% glutamat, 2% glutamat, dan 3% glutamat. Benih ikan nila merah dengan bobot rata-rata 0,25±0,05 g ditebar sebanyak 20 ekor per akuarium dengan dimensi 60x50x40 cm3 dan dipelihara selama 40 hari. Selama masa pemeliharaan, ikan diberi pakan secara at satiation sebanyak lima kali sehari. Hasil penelitian menunjukkan bahwa ikan yang diberi pakan dengan penambahan 1% glutamat memiliki kinerja pertumbuhan yang lebih baik dibandingkan dengan perlakuan lainnya. Sedangkan pakan dengan penambahan 3% glutamat memberikan rasio panjang usus terbaik dibandingkan dengan perlakuan lainnya. Berdasarkan hasil penelitian ini dapat disimpulkan bahwa penambahan 1% glutamat efektif dalam meningkatkan kinerja pertumbuhan benih ikan nila merah Oreochromis niloticus.
Keyword: asam amino, glutamin, glutamat, pertumbuhan, ikan nila merah

Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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