Judul: Produksi pepton ikan gulamah (Argyrosomus sp.) sebagai sumber nitrogen media pertumbuhan mikroba
Abstrak: Iakn dan hasil perikanan lain merupakan sumber protein yang cukup tinggi, namun pemanfaatan hasil perikanan yang terbuang sis-sia karena tidak dapat dikonsumsi sebagai bahan pangan.
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Judul: Optimasi Produksi Bubuk Pepton Dari Limbah Perikanan Dengan Menggunakan Pengering Tipe Pengering Semprot (Spray Dryer)
Abstrak: Pepton merupakan salah satu sumber nitrogen yang utama dalam media perhunbuhan mikroorganisme. Sampai sekarang pada umurnnya pepton masih diimpor dengan jumlah dan biaya yang cukup besar. Perkembangan bioteknologi di Indonesia baik di tingkat penelitian maupun di tingkat komersial saat ini sangat pesat. Oleh karena itu diperlukan pepton yang berkualitas tinggi dengan harga yang murah. Limbah perikanan di Indonesia terutama isi perut ikan pari dan kepala tuna dapat digunakan sebagai bahan baku pembuatan bubuk pepton. Dengan demikian pembuatan bubuk pepton bila dilakukan secara skala industri dapat mengurangi jumlah limbah perikanan yang dapat mencemari lingkungan dan dapat memberikan nilai ekonomi bagi limbah perikanan tersebut. Penelitian dilakukan melalui tiga tahap yaitu tahap penelitian pendahuluan, tahap penelitian utama, dan tahap uji mikrobiologi. Penelitian pendahuluan bertujuan untuk mengetahui parameter optimal hidrolisis enzimatis limbah perikanan (perut ikan pari aan kepala tuna) menggunakan enzim eksternal maupun autolisis untuk menghasilkan pepton. Penelitian utama bertujuan untuk mendapatkan parameter optimal teknik pengeringan dengan menggunakan tipe pengering semprot (spray dryer) dan menguji kemampuan bubuk pepton dari limbah perikanan dalam menunjang pertumbuhan mikroorganisme dibandingkan dengan pepton komersial.
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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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