Judul: Kelayakan Investasi Pembesaran Ikan Air Tawar di Kolam Beton dengan Sistem Konvensional dan Teknologi Recirculating Aquaculture System (RAS) di Purwakarta
Abstrak: Waduk Jatiluhur sebagai tempat budidaya Keramba Jaring Apung terbesar di Purwakarta. Namun, dengan adanya penertiban KJA oleh Pemerintah maka pembudidaya ikan harus pindah ke lokasi baru yaitu di kolam darat. Penelitian ini menganalisis kelayakan investasi perencanaan usaha pembesaran ikan dengan dua sistem berbeda yaitu sistem konvensional (air deras) dan teknologi RAS sebagai pertimbangan untuk pembudidaya yang akan merelokasi kolamnya. Metode penelitian yang digunakan dalam studi meliputi analisis kelayakan aspek non finansial, aspek finansial dan analisis nilai pengganti. Hasil analisis kelayakan non finansial menunjukkan kedua sistem layak dijalankan dan aspek finansial menunjukkan bahwa nilai dari kriteria investasi sistem konvensional lebih tinggi dibanding teknologi RAS. Hasil analisis nilai pengganti menunjukkan bahwa kedua tipe kolam sensitif terhadap penurunan volume produksi ikan. Lokasi kolam dengan sistem konvensional lebih tepat memiliki sumber air mengalir, sedangkan kolam dengan teknologi RAS dapat diterapkan dimana saja.
Keyword: kolam air deras, Recirculating Aquaculture System, pembesaran ikan, nilai pengganti

Judul: Analisis Kelayakan Perencanaan Usaha Ikan Air Tawar di Mitra Fish Farm Kabupaten Bogor.
Abstrak: Usaha perikanan budidaya air tawar berkembang karena tingginya permintaan ikan. Teknologi kolam yang membantu penyediaan produksi adalah kolam air deras dan kolam tanah. Namun, tingginya biaya investasi awal pada pembuatan kolam maka perlu dikaji tingkat kelayakannya berdasarkan aspek non finansial dan aspek finansial. Penelitian ini bertujuan untuk menganalisis kelayakan pengembangan usaha kolam dan pakan buatan pada Mitra Fish Farm. Hasil analisis menyatakan bahwa budidaya ikan mas (skenario I) adalah skenario usaha terbaik diantara ketiga skenario. Hasil sensitivitas juga menyatakan bahwa penurunan jumlah produksi dan penurunan harga jual lebih sensitif dibandingkan dengan peningkatan harga pakan. Hasil ini juga mengindikasikan bahwa pakan alami dapat bertahan dari kenaikan harga hingga 280 persen
Keyword: ikan air tawar, kriteria kelayakan investasi, perencanaan usaha, switching value

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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