Judul: Multiplikasi salak gulapasir (Salacca zalacca) secara invitro dan subkultur dengan metode kultur terapung
Abstrak: Penelitian ini bertujuan memnginduksi multiplikasi salak secara in vitro dengan eksplan berasal dari kecambah dan mengamati pertumbuhan eksplan pada subkultur menggunakan metode kultur terapung. Lima potongan (masing-masing setebal 1 mm) dari pangkal kecambah berumur empat minggu digunakan sebagai eksplan. Eksplan ditanam pada media padat Murashige & Skoog (MS) dengan penambahan 4.0 ppm Benzyl Amino Purin (BAP) dan 200 ppm I-Glutamin. Sebagai perlakuan digunakan empat taraf konsentrasi auksin, yaitu 0.1, 0.4, 0.7, 1.0 ppm 2,4-D. Eksplan yang responsif untuk diregenarasi adalah dari bagian tengah yang merupakan pangkal pelepah daun pertama. Perbedaan konsentrasi auksin tidak berpengaruh nyata terhadap regenerasi.
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Judul: Studi perbanyakan Sedum sarmentosum Bunge. secara in vitro
Abstrak: Tujuan penelitian ini adalah untuk mendapatkan komposisi zat pengatur tumbuh IAA (Indoleacetic acid) dan BAP (Benzilamino purine) yang optimal pada proses multiplikas, serta mendapatkan media inisiasi perakaran yang cocok untuk pengakaran tunas mikro sedum. Penelitian terdiri dari dua tahap percobaan. Percobaan tahap I adalah percobaan multiplikasi. Percobaan ini merupakan percobaan faktorial yang terdiri dari dua faktor yaitu BAP dengan lima taraf konsentrasi (0.0 mg/l, 0.5 mg/l, 1.0 mg/l, 1.5 mg/l dan 2.0 mg/l). Faktor kedua adalah IAA dengan tiga taraf konsentrasi yaitu 0.0 mg/l, 0.1 mg/l dan 0.2 mg/l, sehingga pada percobaan tahap I terdapat 15 perlakuan. Setiap perlakuan diulang 10 kali, setiap ulangan terdiri dari satu botol yang ditanami dua tunas. Eksplan berasal dari tunas hasil perbanyakan Laboratorium Kultur Jaringan BDP IPB. Pengamatan dilakukan selama enam minggu dimulai sejak satu minggu setelah tanam...dst
Keyword: Sedum sarmentosum Bunge, kultur jaringan, faktor penentu

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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