Judul: Kajian aktivitas antibakteri dan antioksidan ekstrak daun sirih  (Piper betle, L.) pada daging sapi giling
Abstrak: Pemanfaatan daun sirih (Piper betle, L.) dalam dunia pengobatan sudah lama dikenal, hal ini berkaitan dengan adanya kandungan senyawa fenolik alami yang mempunyai aktivitas sebagai antibakteri. Beberapa penelitian terdahulu telah membuktikan bahwa selain bersifat antibakteri, senyawa fenolik yang terdapat dalam daun sirih mempunyai aktivitas sebagai antioksidan.
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Judul: Pengaruh konsentrasi bubuk daun sirih kuning terhadap pertumbuhan beberapa jenis bakteri dan aplikasinya pada daging sapi segar
Abstrak: Daun sirih merupakan tanaman yang sudah lama dikenal dan dimanfaatkan oleh masyarakat Indonesia terutama penggunaannya dalam bidang kesehatan. Kandungan senyawa fenol dalam sirih membuat tanaman ini mempunyai kemampuan untuk menghambat pertumbuhan dan membunuh mikroba tertentu yang sering menyebabkan penyakit. Tiga jenis daun sirih yaitu sirih hijau, sirih kuning dan sirih merah dipelajari aktivitas antimikrobanya terhadap dua bakteri yaitu Pseudomonas fluorescens dan Escherichia coli. Hasil pengujian menunjukkan bahwa sirih hijau memberikan zone penghambatan paling tinggi dibandingkan dua jenis sirih lainnya. Dalam penelitian selanjutnya dipilih sirih kuning dengan pertimbangan bahwa jenis sirih ini mempunyai aktivitas antimikroba yang cukup tinggi terhadap dua mikroba uji dan lebih mudah diperoleh. Kemampuan bubuk sirih kuning dalam menghambat pertumbuhan dan membunuh Pseudomonas fluorescens, Escherichia coli dan Staphylococcus aureus diteliti lebih lanjut. Bubuk sirih kuning ditaburkan pada potongan daging sapi, dikemas dalam plastik dan disimpan pada dua suhu yaitu suhu dingin (5°C) dan suhu ruang serta diamati kemampuan sirih untuk menghambat pertumbuhan bakteri S. aureus, Pseudomonas sp dan total mikroba. Pengamatan dilakukan setiap empat jam selama 24 jam terhadap daging yang disimpan pada suhu ruang dan setiap tiga hari selama 9 hari untuk penyimpanan pada suhu dingin. ...
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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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