Judul: Uji daya gabung khusus galur-galur jagung manis (Zea Mays Saccharata Sturt)
Abstrak: Penelitian ini bertujuau uutuk menguji daya gsbung khusus terhadap lima galur jagung Manis, sehingga dapat diketahui galur-galur mana yang mempunyai daya gabung khusus terbaik dan memiliki harapan untuk dikembangkan menjadi jagung hibrida. Peroobaan dilaksauakau di Kebun Peroobaan Inlitbio (Instalasi Penelilian Biologi), Pacet, Ciaojur pada ketinggian 1150 m dpl, dari bulan Januari hiugga Mei 2002. Rancangan yang digunakan adalah RAK (Rancangao Acak Kelompok) dengao tiga ulangan. Secara keseluruhan terdapat 57 satuan percobaan. Benih tiap satuan percobaan ditauam pada petak laban berukwan 1O x 1m. Jarak tanam yang digunakau ialah 1 x 0.33 m deugao 2 benih/lubang.
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Judul: Uji daya gabung umtun galur-galur jagung manis (Zea mays saccharata Sturt.) yang berasal dari populasi SD 2
Abstrak: Penelitian ini bertujuan untuk menguji daya gabung tuntun (DGU) galur- galur jagung manis yang diperoleh dari SD 2. Percobaan dilaksanakan di kebun percobaan Cikarawang, Kabupaten Bogor pada minggu pertama Februari hingga minggu keempat April 2001. Pengujian daya gabung tuntun dilakukan terhadap 14 galur jagung manis yang berasal dari SD 2 dan disilangkan kembali ke varietas SD 2. Sebagai kontrol digunakan jagung SD 2. Rancangan yang digunakan adalab Rancangan Acak Kelompok (RAK) dengan tiga kali ulangan. Secara keseluruhan terdapat 45 satuan percobaan. Benih tiap satuan percobaan ditanam pada petak laban berukuran 2 m x 10 m. Jarak tanarn yang digunakan ialah 1 m x 0.4 m dengan dua benih per lubang. Pada percobaan ini tidak ditemui adanya efek heterosis. Galur yang diuji tidak menunjukkan peningkatan ketegaran dibanding tetuanya, yaitu SD 2. Terdapat lima galur yang memiliki DGU yang baik dibandingkan nilai tengab. Kelima galur tersebut ialah G3, G6, G7, G 10 dan G 12. Silangan kelima galur ini memiliki produksi masing-masing 3.32, 3.28, 2.81, 2.59 dan 2.82 kg/petak. Galur- galur diatas perIu diuji lanjut untuk mengetahui daya gabung khusus.
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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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