Judul: Pengaruh Pemberian Fosfor dan Kalium terhadap Pertumbuhan, Produksi dan Mutu Minyak pada Dua Klon Mentha Piperita
Abstrak: Percobax ini bertujuan untuk mempelajari pengaruh pemberian fosfor can kalium eerta interaksinya terhadap pertumbuhan, produksi dan mutu minyak pad2 dua klon Mentha piperita, Percobaan dilaksanakan di Kebun Percobaan Balittro Manoko Lembang, mulai akhir januari 1989 sampai dengan awal Agustus 1989.
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Judul: Pengaruh pemupukan N dan K terhadap pertumbuhan, produksi dan mutu minyak pada Mentha piperita L. klon New Zealand
Abstrak: Percobaan ini bertujuan untuk mempelajari pengaruh pemupukan N dan K serta interaksinya terhadap pertumbuhan dan hasil serta mutu minyak permen Mentha piperita. Percobaan dilaksanakan di Kebun Percobaan Manoko, Lembang, Kabupaten Bandung, Jawa Barat. Berlangsung mulai bulan Februari 1989 sampai bulan Agustus 1989. Bahan tanaman yang digunakan berupa stek stolon Mentha piperita klon New Zealand dengan panjang 15 cm. Stek stolon yang telah dipersiapkan ditanam satu bibit per lubang dengan jarak tanam 50 cm x 40 cm. Petak percobaan berukuran 3 m x 3 m sebanyak 27 petak. Percobaan dilakukan di lapang dengan menggunakan Rancangan Acak Kelompok susunan faktorial dengan pupuk N sebagai faktor pertama terdiri dari tiga taraf dosis yaitu O kg N/ha, 100 kg N/ha, dan 200 kg N/ha. Pupuk K sebagai faktor kedua dengan tiga taraf dosis yaitu O kg K20/ha, 75 kg K20/ha, dan 150 kg K20/ha. Masing-masing unit percobaan terdiri dari tiga ulangan. IPI Pupuk N diberikan dua kali, setengah dosis pada saat tanam dan setengah dosis sisanya pada 8 MST. Pupuk K diberikan sekaligus pada saat tanam. Peubah yang diamati meliputi panjang sulur, jumlah cabang, jumlah anakan, Indeks Luas Daun (ILD), produksi kering, produksi minyak dan mutu minyak. Pemberian N tidak berpengaruh nyata terhadap panjang sulur, jumlah cabang, Indeks Luas Daun (ILD) dan produksi kering, tetapi pemberian N berpengaruh nyata terhadap jumlah anakan pada umur 20, 22, dan 24 MST. Khusus untuk percobaan ini pemberian N meningkatkan produksi minyak, kadar menthol, menthon dan menthil asetat yang diikuti penurunan kadar menthofuran. Pemberian K tidak berpengaruh nyata terhadap panjang sulur, jumlah cabang, Indeks Luas Daun (ILD) dan produksi kering, tetapi pemberian K berpengaruh nyata terhadap jumlah anakan pada umur 22 dan 24 MST. Khusus untuk percobaan ini pemberian K meningkatkan produksi minyak, kadar menthon, menthol, dan menthil asetat yang diikuti penurunan kadar menthofuran. Terjadi interaksi antara pemupukan N dan K terhadap panjang sulur pada umur 10 MST.
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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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