Judul: Produksi sirup fruktosa dari inulin Dahlia pinnata Cav. secara hidrolisis asam
Abstrak: Sirup fruktosa merupakan pemanis alternatif yang semakin luas digunakan karena tingkat kemanisannya yang lebih tinggi dibandingkan sukrosa, yaitu 1,7 kali namun rendah kalori (tidak tercerna oleh tubuh). Selain rendah kalori, fruktosa pun mampu menutupi rasa pahit (bitter after taste) dari sakarin. Oleh karena itu fruktosa baik dikonsumsi oleh penderita diabetes. Sirup fruktosa yang selama ini dikenal diproduksi dari pati singkong, dapat pula diproduksi dari inulin yang berasal dari umbi dahlia (Dahlia pinnata Cav.) yang ternyata sangat mudah dibudidayakan di Indonesia. Di negara-negara maju, sirup fruktosa sudah menjadi bahan konsumsi sehari-hari, walau tidak dapat dikonsumsi secara langsung. Produksi sirup fruktosa dari inulin dengan hidrolisis kimiawi menggunakan asam dapat digolongkan sebagai proses produksi yang sangat mudah bila dibandingkan dengan proses lainnya (hidrolisis enzimatis). Hal ini terlihat dari segi prosesnya maupun dari hasilnya. Dari segi proses produksi, sirup ini menguntungkan karena sangat singkat dan mudah karena proses tersebut tidak memerlukan bahan serta alat yang khusus sehingga tidak membutuhkan biaya produksi yang terlampau tinggi. Dilihat dari segi hasilnya, diketahui bahwa nilai atau kadar gula pereduksi serta rendemen fruktosa yang dihasilkan sangat baik. Dengan demikian sirup yang dihasilkan termasuk dalam sirup fruktosa. ...
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Judul: Produksi Sirup Fruktosa dari Inulin Umbi Dahlia Dalam Reaktor Sinambung Unggun Terkemas Menggunakan Enzim Inulinase Imobil
Abstrak: Sirup fruktosa merupakan alternatif bahan pemanis lain yang kebutuhannya semakin lama semakin meningkat. Selain dari pati, sirup ini dapat juga diproduksi dari inulin yang berasal dari umbi dahlia (Dahlia pinnata Cav.) yang relatif mudah dibudidayakan di Indonesia. Gula cair dari inulin ini mempunyai banyak kelebihan dibandingkan gula cair dari pati, diantaranya rendemennya tinggi (sampai 97 persen) dan prosesnya singkat (hanya 1 tahap).
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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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