Judul: Kajian konversi limbah padat jerami padi menjadi biogas
Abstrak: Jerami merupakan bagian vegetatif dari tanaman padi (batang, daun, dan tangkai malai). Pada waktu tanaman dipanen, jerami adalah bagian tanaman yang tidak diambil. Produksi gabah nasional adalah 54 juta ton (2005), sehingga diperkirakan sekitar 80 juta ton jerami dihasilkan. Pada tahun 2010 diperkirakan produksi gabah 57 juta ton, sehingga akan dihasilkan 84 juta ton jerami padi. Disisi lain kebutuhan energi terus meningkat, sehingga menimbulkan kelangkaan karena sumber energi bersifat tidak terbarukan. Oleh karena itu perlu dikembangkan alternatif energi baru terbarukan, yang salah satunya adalah biogas. Biogas dapat dihasilkan dari fermentasi bahan-bahan organik pada jerami padi oleh bakteri anaerobik. Pemanfaatan jerami untuk produksi biogas bisa meningkatkan nilai tambah jerami dan sumber energi terbarukan.
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Judul: Pengembangan Teknologi Biogas dengan Pemamfaatan Kotoran Ternak dan Jerami Padi Sebagai Alternatif Energi Pedesaan.
Abstrak: Indonesia merupakan negara agraris yang kaya akan sumber biomassa. Sumber biomassa tersebut tersebar hampir di seluruh daerah, baik berupa limbah pertanian ataupun produksi hasil hutan. Sejalan dengan peningkatan produksi pertanian dan peternakan, maka jumlah limbah yang dihasilkan dari kedua sektor ini juga cukup besar. Dua macam limbah yang cukup besar jumlahnya dari pertanian dan peternakan adalah jerami dan kotoran ternak. Limbah-limbah ini selain belum dimanfaatkan secara maksimal, limbah-limbah tersebut juga ikut memberi peran dalam meningkatkan efek rumah kaca yang menyebabkan pemanasan global. Teknologi pengolahan limbah pertanian yang sangat efektif untuk pemecahan masalah di atas adalah teknologi biogas. Bertolak dari masalah tersebut, maka penelitian ini bertujuan mencari kombinasi terbaik antara jerami dan kotoran ternak dalam memproduksi biogas.
Keyword: Teknologi Biogas, Pemanfaatan Kotoran Ternak, Jerami Padi, Alternatif Energi Pedesaan, Sumber biomassa

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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