Judul: Pengamatan Serangga Pengganggu Komoditi Beras Dan gabah Di Gudang Bulog Tambun Serta Mempelajari Cara-Cara Pengendaliannya Di Gudang Bulog Tambun Dan Dolog Jakarta
Abstrak: Praktek lapang ini dilakukan di Bulog Tambun dan Dolog Jakarta dimulai tanggal 9 April 1984 sampai tanggal 9 Juni 1984. Tujuan praktek lapang ini adalah untuk mengetahui serangga pengganggu komoditi beras dan gabah serta mempelajari cara-cara pengendaliannya. Metode yang digunakan untuk mengamati serangga pengganggu pada komoditi beras yaitu dengan memasang perangkap kardus pada permukaan karung dan pengambilan contoh beras dengan spear sampler. Sedang pada komoditi gabah pengambilan contoh dilakukan dengan menggunakan pengambil contoh bertenaga mesin. Serangga hama gudang mampu menurunkan beras dan gabah baik secara kualitatif maupun kuantitatif. Berdasarkan hasil pengamatan di gudang beras dan gabah di Bulog Tambun, serangga yang didapatkan dari beras dari yang terbanyak sampai yang paling sedikit adalah Tribolium castaneum, Ahasverus advena, Rhyzoperta dominica, Oryzaephilus surina- mensis, Sitophilus sp., Cryptolestes sp. dan Psocids. Pada gabah serangga yang didapatkan dari yang terbanyak sampai yang paling sedikit adalah Cryptolestes sp., Rhyzoperta dominica, Ahasverus advena, Typaea stercorea, Tribolium castaneum dan Sitophilus sp..
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Judul: Pengamatan Serangga Pengganggu Bawang Daun (Allium fistulosum Linn.) di Beberapa Desa Kecamatan Cisarua Kabupaten Bogor
Abstrak: Tujuan praktek lapang ini adalah mengetahui persentase serangan serangga pengganggu bawang daun. Metode yang digunakan adalah mengadakan wawancara dengan petani dan pengamatan langsung di lapang. Serangga pengganggu utama yang ditemukan di lapang adalah Spodoptera exigua Hubn. (Lepidoptera: Noctuidae ) dan Thrips sp. (Thysanoptera: Thripidae). Persentase serangan kedua serangga pengganggu tersebut tergolong kategori ringan. ...
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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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