Judul: Fermentasi dan Karakterisasi Bekasam Ikan Nila (Oreochromis sp.) dengan Penambahan Starter Bakteri Asam Laktat Asal Bekasam
Abstrak: Fermentasi bekasam menggunakan starter campuran Lactobacillus plantarum SK(5) dan Pediococcus pentosaceus BP(20) telah diketahui menghasilkan karakteristik produk yang lebih baik dibanding penggunaan starter tunggal. Penelitian ini bertujuan untuk menentukan konsentrasi starter campuran dua bakteri tersebut yang menghasilkan bekasam dengan karakteristik terbaik. Konsentrasi starter yang digunakan dalam proses fermentasi bekasam yaitu 5%, 10%, 15%, dan 20%. Karakteristik kimiawi dan mikrobiologis bekasam diamati selama 8 hari untuk mendapatkan konsentrasi yang tepat. Bekasam dengan perlakuan terpilih dikarakterisasi kandungan asam amino, asam lemak, aktivitas antioksidan, dan kadar garamnya. Hasil penelitian menunjukkan bahwa nilai total bakteri asam laktat (BAL), total asam tertitrasi (TAT), dan pH bekasam dengan starter campuran pada keempat perlakuan memiliki pola yang sama. Konsentrasi starter 10% menghasilkan bekasam dengan nilai total bakteri asam laktat dan total asam tertitrasi tertinggi dibandingkan bekasam dengan konsentrasi starter lainnya. Glutamat merupakan asam amino yang paling banyak ditemukan pada bekasam, sedangkan asam lemak tak jenuh mendominasi kandungan asam lemak bekasam. Bekasam yang dihasilkan memiliki nilai IC50 sebesar 2,66 mg/mL dan kadar garam sebesar 3,97%.
Keyword: bakteri asam laktat, bekasam, fermentasi

Judul: Fermentasi Spontan Bekasam Ikan Nila (Oreochromis niloticus) Menggunakan Kerak Nasi Kering
Abstrak: Bekasam merupakan produk fermentasi yang terbuat dari ikan air tawar, garam, dan sumber karbohidrat. Kerak nasi kering merupakan salah satu sumber karbohidrat yang dapat digunakan dalam pembuatan bekasam. Penelitian ini bertujuan untuk menentukan pengaruh penambahan kerak nasi kering terhadap karakteristik mikrobiologis dan kimiawi bekasam serta menentukan jumlah penambahan kerak nasi kering dan waktu fermentasi terpilih. Pembuatan bekasam menggunakan kerak nasi kering 25% (b/b) dan 50% (b/b). Fermentasi dilakukan selama 12 hari pada suhu ruang. Analisis mikrobiologis dan kimiawi dilakukan setiap 3 hari. Hasil analisis menunjukkan fase log total mikroba dan BAL terjadi sampai hari ke-6 kemudian stasioner sampai hari ke-12. Total asam tertitrasi mengalami peningkatan sedangkan nilai pH menurun selama fermentasi. Penambahan kerak nasi kering tidak memberikan pengaruh terhadap komposisi kimia produk akhir bekasam. Penambahan kerak nasi kering 25% dengan waktu fermentasi 6 hari merupakan produksi bekasam terpilih.
Keyword: bakteri asam laktat, bekasam, kerak nasi, komposisi kimia

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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