Judul: Optimisasi penyusunan formula makanan ikan berbentuk pellet
Abstrak: Optimisasi formulasi makanan berbentuk pellet dilakukan dengan mengatur jenis bahan dan jumlah bahan formula. formulasi Optimisasi bertujuan agar makanan dapat menekan biaya dalam serta mutu penyusunan serendah mungkin dengan mutu sebaik mungkin. Metode yang dipergunakan untuk melakukan optimisasi adalah teknik "Program Linear". Bahan baku yang dipergunakan untuk campuran formula terdiri atas bungkil kedele, jagung, polar, bungkil wijen, dikalsium pospat, tepung kerang, minyak ikan, tepung ikan dan tepung daging. Pencampuran bahan-bahan dilakukan berdasarkan standard mutu yang sudah ada, hanya ditambahkan lagi variasi dari penggunaan karbohidrat yaitu untuk formula 1 antara 25 sampai 30 persen, formula 2 antara sampai 35 persen, formula 3 antara 35 sampai 40 persen formula 4 antara 40 sampai 45 persen.
Keyword: Pellets, Fish feeding

Judul: Studi stabilitas dalam air dan daya pikat pakan udang bentuk pellet
Abstrak: Penelitian ini bertujuan untuk mendapatkan cara pembuatan pakan udang bentuk pellet yang stabil dalam air dan menarik bagi udang, sehingga cepat dimakan oleh udang dan tidak mencemari air. Jenis bahan pengikat yang diteliti adalah, terigu, tapioka, tepung ketan, karboksilmetil selulosa dan gelatin masing-masing sebanyak 5 persen dari berat formula. Kemudian dipanaskan dengan uap air panas pada suhu 100 110 C yaitu pada tekanan 1,8 kg/cm, selama 25, 35 dan 45 menit. Sebagai formula standar digunakan formula dari Balai Penelitian Perikanan Air Tawar, Bogor. Pellet yang diperoleh dari hasil perlakuan jenis bahan pengikat dengan lama pemanasan diamati (1) komposisinya, (2) sifat fisiknya yang meliputi densitas, kecepatan tenggelam ke dalam air, stabilitas dalam air (uji pecah, dispersi padatan, kadar protein terdispersi dan kadar lemak terdispersi), suhu peleburan pati bahan pengikat dengan alat Differential Scanning Calorimeter, kekental an dengan Stormer Viscosimeter, dan (3) pengamatan mikroskopis dengan Polarized Light Microscope dan Scanning Electron Microscope. Bahan pemikat yang dipelajari yaitu tepung ikan, tepung kepala udang, tepung cumi, tepung rebon, tepung udang, tepung kerang hijau, dan terasi rebon masing- masing sebanyak 10 persen dari berat formula pakan udang. Uji daya pikat pakan dilakukan pada udang windu tingkat juvenil pada fase pembesaran dan yang diamati adalah jumlah udang yang makan atau mendekati pakan, serta jumlah pakan yang dikonsumsi udang. Pengamatan dilakukan dua kali dalam sehari yaitu pagi jam 9.00 dan sore jam 18.00 dengan mengganti pakan yang baru, selama tiga hari berturut-turut.
Keyword: Fish feeding, Pellets

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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