Judul: Keandalan Komposit Resin dan Serbuk Gergaji Sebagai Bahan Penambal Luka Terbuka pada Batang Pohon.
Abstrak: Pohon memiliki peranan yang sangat penting di dalam lingkungan perkotaan karena dapat memperbaiki kualitas lingkungan, serta meningkatkan kenyamanan, dan estetika. Namun, tidak semua pohon di perkotaan memiliki kondisi kesehatan yang baik, karena sering kali ditemukan adanya luka terbuka (exposed cavity) pada batang pohon. Luka terbuka pada batang pohon dapat menurunkan biomekanik dan estetika pohon tersebut. Salah satu cara untuk mengatasi hal tersebut adalah dengan melakukan penambalan luka terbuka. Suatu penelitian telah dilakukan untuk mengetahui keandalan komposit resin polyester dan serbuk gergaji kayu merbau (Intsia bijuga O.K) sebagai bahan penambal luka terbuka pada batang pohon krey payung (Filicium decipiens). Tiga formula resin : serbuk gergaji yang digunakan adalah 100% : 0%, 90% : 10%, dan 80% : 20%. Hasil penelitian menunjukkan bahwa komposit resin dan serbuk gergaji memiliki kerapatan 1.058 – 1.149 g/cm3, MOE 16335 – 29540.01 kg/cm2, MOR 392.28 – 784.87 kg/cm2, dan kekerasan 304.02 – 1951.02 kg/cm2. Kualitas hasil penambalan sangat baik ditinjau dari kepadatan massa yang tinggi dan tidak adanya pecah atau retak yang ditemukan pada hasil penambalan.
Keyword: luka terbuka, penambalan, resin, serbuk gergaji, Intsia bijuga

Judul: Karakterisasi Luka Terbuka pada Batang Pohon Trembesi dan Flamboyan serta Kualitas Hasil Penambalannya dengan Polyurethane.
Abstrak: Pohon merupakan bagian yang penting dalam tata ruang perkotaan dan memiliki fungsi sebagai ameliorasi iklim, kegunaan arsitektur, dan penunjang keindahan. Di Provinsi Jakarta banyak pohon peneduh yang mengalami luka terbuka sehingga biomekanik, kebugaran dan nilai estetikanya menurun. Namun demikian karakteristik luka terbuka pada pohon tersebut belum pernah dilaporkan secara ilmiah. Penelitian dilakukan untuk mengetahui karakteristik luka terbuka pada pohon Trembesi dan Flamboyan di Kawasan Sudirman Central Bussiness District (SCBD), dan keandalan busa polyeurethane sebagai penambal luka terbuka pada pohon tersebut. Hasil penelitian menunjukkan bahwa sebagian besar luka pada pohon di Kawasan SCBD, Jakarta Selatan terdapat pada cabang utama (45%), Luka yang banyak ditemukan adalah luka akibat pelapukan pada bekas pemangkasan cabang. kualitas hasil penambalan luka cukup baik karena hanya 5% tambalan yang pecah atau retak serta kepadatan massa hasil penambalan luka mencapai 30% dari kepadatan massa batang pohon.
Keyword: flamboyan, luka terbuka, pelapukan, penambalan luka, polyurethane, trembesi.

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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