Judul: Aplikasi Response Surface Methodology untuk Optimasi Ekstraksi Gelatin dari Kulit Ikan Patin dan Pemanfaatannya sebagai Kapsul Keras
Abstrak: Kulit ikan patin sangat potensial menjadi sumber gelatin, namun proses ekstraksinya masih belum optimal. Penelitian ini bertujuan mengoptimasi proses ekstraksi gelatin dari kulit ikan patin dengan Response Surface Methodology (RSM) dan menggunakan gelatin yang didapat sebagai bahan baku kapsul keras. Rancangan eksperimen yang digunakan yaitu Central Composite Design (CCD) yang terdiri dari dua variabel yaitu konsentrasi asam sitrat dan waktu ekstraksi. Konsentrasi asam sitrat berkorelasi positif terhadap respon rendemen, kadar air, kadar abu, pH, viskositas, dan setting point sedangkan waktu ekstraksi berpengaruh terhadap rendemen, kekuatan gel, kadar air dan setting point. Interaksi kedua faktor ini mampu meningkatkan karakteristik gelatin. Ekstraksi yang optimal dengan konsentrasi asam sitrat 0.297% dan waktu ekstraksi 8 jam menghasilkan gelatin dengan kualitas yang telah sesuai dengan standar GMIA 2019 dan SNI 0637351995. Karakteristik kapsul yang dihasilkan telah sesuai dengan standar Departemen Kesehatan RI (1995). Hasil ini menunjukkan proses ekstraksi yang dilakukan mampu menghasilkan gelatin yang dapat digunakan sebagai bahan baku industri kapsul keras yang sesuai standar.
Keyword: catfish, gelatin, hard capsule, process optimization, RSM

Judul: Karakteristik dan Optimasi Gelatin dari Kulit Ikan Patin serta Pemanfaatannya sebagai Kapsul Keras
Abstrak: Gelatin merupakan suatu polimer alami yang diperoleh melalui proses hidrolisis dan dapat dimanfaatkan sebagai bahan baku untuk pembuatan kapsul keras. Formulasi untuk menghasilkan gelatin dengan hasil yang optimal dan sesuai standar GMIA 2019 serta SNI 1995 sangat dibutuhkan. Tujuan penelitian ini yaitu menentukan karateristik dan optimasi gelatin dari kulit ikan patin (P. hypophthalmus) menggunakan Response Surface Methodology (RSM) dan menentukan karakteristik kapsul keras. Rancangan eksperimen yang digunakan yaitu Central Composite Design (CCD) yang terdiri dari dua faktor (konsentrasi asam sitrat dan waktu ekstraksi) dengan 8 respon (rendemen, kadar air, kadar abu, pH, kekuatan gel, viskositas, dan setting point). Hasil optimasi menghasilkan respon optimum pada konsentrasi asam sitrat 0.337% dan waktu ekstraksi 7.432 jam. Nilai respon hasil validasi yang diperoleh rendemen 19.08±0.08%, kadar air 10.24±0.23%, kadar abu 0.58±0.01%, derajat keasaman (pH) 4.47±0.10, kekuatan gel 147.08±0.92 bloom, viskositas 55.50±0.71 mps, dan setting point 18.50±0.00 ℃. Karakteristik cangkang kapsul dari gelatin kulit ikan patin berupa dimensi, kadar air, kadar abu, derajat keasaman (pH), dan waktu hancur telah sesuai standar kapsul komersial menurut Departemen Kesehatan RI (1995).
Keyword: gelatin, kapsul keras, kulit, RSM

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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