Judul: Efektivitas Penggunaan Enzim Komersial pada Pakan dengan Kandungan Protein yang Berbeda terhadap Kinerja Pertumbuhan Elver Ikan Sidat Anguilla bicolor bicolor.
Abstrak: Penelitian ini bertujuan untuk menganalisis kinerja pertumbuhan terbaik elver ikan sidat Anguilla bicolor bicolor yang diberikan pakan berkadar protein berbeda dengan penambahan enzim komersial. Ikan sidat dengan bobot 5,00±0,56 gekor-1 dipelihara dalam akuarium dengan volume 40 L pada padat tebar 4 gL-1 selama 60 hari. Penelitian ini menggunakan rancangan acak lengkap yang terdiri atas empat perlakuan dan tiga ulangan pada masing-masing perlakuan. Perlakuan tersebut adalah pakan yang mengandung protein 35% dengan enzim komersial 0,25 g kg-1dikodekan sebagai P1(35%;0,25 g kg-1), P2 (40%;0,25 g kg-1), P3 (45%;0,25 g kg-1), dan P4 (45%;0 g kg-1). Hasil penelitian menunjukkan bahwa nilai laju pertumbuhan mutlak, laju pertumbuhan spesifik, laju pertumbuhan mutlak biomassa, biomassa akhir, rasio konversi pakan, dan retensi protein pada masing-masing perlakuan menunjukkan perbedaan yang nyata (P<0,05). Derajat kelangsungan hidup, retensi lemak, dan koefisien keragaman bobot tidak menunjukkan perbedaan yang nyata antar perlakuan (P>0,05). Dapat disimpulkan bahwa kinerja pertumbuhan terbaik terdapat pada elver ikan sidat A.bicolor bicolor yang diberikan pakan dengan kandungan protein 40% dan penambahan enzim 0,25 g kg-1(P2).
Keyword: Anguilla bicolor bicolor, enzim, kinerja pertumbuhan, protein

Judul: Efektivitas Penambahan Enzim Komersial pada Pakan dengan Kadar Protein yang Berbeda terhadap Kinerja Pertumbuhan Pembesaran Ikan Sidat Anguilla bicolor bicolor
Abstrak: Upaya untuk mengoptimalkan pertumbuhan dan efisiensi pakan ikan sidat Anguilla bicolor bicolor dapat dilakukan dengan penambahan enzim. Penelitian ini bertujuan untuk menganalisis efektivitas penggunaan enzim pada pakan dengan kadar protein yang berbeda terhadap kinerja pertumbuhan pembesaran ikan sidat. Perlakuan pada penelitian ini terdiri dari pemberian pakan dengan kadar protein berbeda dan dosis enzim yaitu (A) 35%;0,25 g/kg, (B) 40%;0,25 g/kg, (C) 45%;0,25 g/kg, dan (D) 45%;0 g/kg. Ikan sidat dipelihara dalam akuarium berukuran 50 x 40 x 35 cm3 dengan tinggi air 20 cm. Bobot rata-rata awal ikan uji 19,25 ± 0,80 g dengan padat tebar awal 4 g/L. Hasil penelitian menunjukkan bahwa perlakuan tidak menghasilkan perbedaan nyata (P>0,05) terhadap biomassa akhir, jumlah konsumsi pakan, laju pertumbuhan mutlak bobot, laju pertumbuhan spesifik, rasio konversi pakan, retensi protein, retensi lemak, serta derajat kelangsungan hidup. Perlakuan menghasilkan perbedaan nyata terhadap koefisien keragaman bobot (P<0,05). Perlakuan terbaik adalah pakan dengan kadar protein 35% dengan enzim 0,25 g/kg yang menghasilkan koefisien keragaman bobot terendah.
Keyword: enzim, ikan sidat, kadar protein, pertumbuhan

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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