Judul: Keanekaragaman dan Kelimpahan Arthropoda pada Perkebunan Teh 0-300 meter dari Tepi Hutan di PTPN VIII Gunung Mas, Kabupaten Bogor
Abstrak: Knowledge of pests and natural enemies diversity and abundance on the tea plantation is the essential considetarion for pest control descision by integrated pest management system. This study, conducted in PTPN VIII Gunung Mas tea plantation during 3 months, considered the effect of forest edge through tea boundaries (0-100, 100-200, 200-300 meters from forest edge) on diversity, abundance and family function proportion of Arthropods by pitfall trap, sweep net and branches beating methods for a week. Totally, the classes of Arthropod are Arachnida (3 orders, 19 families, and 1383 species), Diplopoda (3 orders, 6 families, and 27 species) and Insecta (13 orders, 73 families, and 5048 species). The 0-100 meters tea plantation from forest edge has highest number of Arthropods diversity. The highest number of Arthropods abundance is in 100-200 meters from forest edge. A lot of Arthropods have a role as predator on tea plantation (55.53% from total Arthropods). The proportions of herbivore, detrivore, parasitoid, and other are 21.52%, 20.94%, 1.38%, and 0.63%.
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Judul: Keanekaragaman dan Kelimpahan Arthropoda pada Perkebunan Teh 600-900 meter dari Tepi Hutan di Kebun PTPN VIII Gunung Mas, Bogor, Jawa Barat
Abstrak: Tea (Camellia sinensis) is one of the plantation commodities that have a strategic role for the Indonesian economy. Almost of every year tea production has decreased, this is due to pest attack. Pest is one part of Arthropoda herbivore. Diversity and abundance Arthopoda in tea gardens need to know because some Arthropods have a beneficial role. The experiment was conducted to identify the diversity and abundance Arthropoda at tea plantation PTPN VIII Gunung Mas,. The research used three sampling methods, that is: net insect, Branches beating and pitfall trap. Identification of Arthropods in the Laboratory Bioecology Insects, Department of Plant Protection, Faculty of Agriculture, Bogor Agricultural University. Diversity Arthropoda 600 meter to 700 meters from forest edge has highest number is 49 family. The Arthropod proportions as predator is 46%, parasitoid 6%, herbivor 41% and detrivor 7%. Tea plants are generally much damage caused by Helopeltis sp. and Hyposidra talaca. Arthropod predators, parasitoids and herbivors most commonly found with nets and detrivor is most widely with pitfall trap method.
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Judul: Formulasi Hamilton Untuk Menggambarkan Deformasi Gelombang Soliter Dengan Dasar Tidak Rata Pada Fluida Dua Lapisan
Abstrak: Gelombang internal adalah suatu gelombang yang muncul di bawah permukaan laut sehingga gelombang ini tidak teramati secara kasat mata. Formulasi Hamilton dirumuskan untuk menjelaskan gerak gelombang ini. Dalam hal ini diasumsikan bahwa fluida yang ditinjau terdiri atas dua lapisan dengan masing-masing lapisan memiliki rapat massa yang konstan. Selain itu, diasumsikan pula fluida yang ditinjau berupa fluida tak mampat (incompressible) dan tak kental (invicid). Formulasi Hamilton dilakukan dengan meninjau fluida dua lapisan yang berada pada domain yang dibatasi oleh batas atas yang rata dan batas bawah yang tidak rata. Hamilton (energi total)-nya didefinisikan sebagai penjumlahan antara energi kinetik dan energi potensialnya. Karena energi kinetik tidak secara eksplisit dinyatakan dalam peubah fisis, maka digunakan metode asimtotik untuk menentukan energi totalnya. Dalam hal ini diasumsikan bahwa gelombang interfacial yang ditinjau cukup panjang, dan amplitudo yang cukup kecil. Persamaan Korteweg de- Vries (KdV) diperoleh, jika disumsikan bahwa gelombang interfacial hanya merambat pada satu arah, sedangkan jika gelombang tersebut merambat ke dua arah, diperoleh persamaan Boussinesq.
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