Judul: Studi irradiasi sinar gamma pada tanaman iles-iles (Amorphophallus muelleri Blume)
Abstrak: Konjac (Amorphophallus muelleri Blume) is a triploid tuberous crop plant which produces apomictic seeds. It makes the genetic diversity of the plant is considered low. The objective of this research was to increase the diversity of konjac and to get a potential mutan in order to develop breeding materials. Gamma irradion was used in this experiment. The gamma irradiation was applicated in konjac’s seeds, using eleven treatments including control, from 0 Gy to 100 Gy with 10 Gy in every interval of the treatment. Result showed that control (0 Gy) and 10 Gy treatments that had succesfully produced potential mutans . Treatments level higher than 20 Gy to100 Gy caused mortal plant or kept seeds dormant until the end of the experiment. The 10 Gy treatment significantly delay seed sprouting more than five weeks after planting. All of the vegetative parameters of 10 Gy’s treated plants significantly exhibited lower productivity than those of control plants. Some mutans were observed on the leaf morphology. This experiment revealed that A. muelleri seed was sensitive to gamma irradiation.
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Judul: Pengaruh Radiasi Sinar Gamma Terhadap Keragaman Tanaman Gloksinia (S;Uu;Ugia Speciosa) Dari Eksplan Pucuk Yang Diperbanyak Secara In Vitro
Abstrak: Percobaan ini dilakukan di Laboratorium Kultur Jaringan Jurusan Budidaya Pertanian, Institut Pertanian Bogor dari bulan April sampai Desember 1996 bertujuan untuk mengetahui pengaruh radiasi sinar gamma terhadap keragaman gloksinia (Sinningia speciosa) dari eksplan pucuk yang diperbanyakan secara in vitro. Perlakuan pemberian radiasi sinar gamma bersumber dari atom mes dilakukan di Laboratorium IImu Hayat, Pusat Antar Universitas, IPB. Sedangkan aklimatisasi tanaman dilaksanakan di screen-house Laboratorium Kultur Jaringan, Baranangsiang. Bahan tanaman yang digunakan adalah meristem pucuk tunas gloksinia in vitro. Tunas gloksinia tersebut diberi perlakuan radiasi sinar gamma dengan dosis 0, 10,20, 30 dan 40 Gy. Kemudian eksplan ditanam pada medium dasar Murashige dan Skoog (MS) dengan penambahan IAA 0.1 ppm dan BAP 0.5 ppm selama 7 minggu. Setelah multiplikasi tunas dipindahkan ke media perakaran yaitu media MS dengan penambahan IBA 0.1 ppm selama 4 minggu. Plantlet yang telah berakar diaklimatisasi selama 4 minggu, baru kemudian dipindahkan ke pot sampai tanaman berbunga sempuma. Percobaan ini menggunakan satu faktor perlakuan yaitu dosis radiasi sinar gamma dengan rancangan acak lengkap. Taraf dosis radiasi adalah 0, 10, 20, 30, dan 40 Gray dengan ulangan sebanyak 50 satuan ulangan.
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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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