Judul: Keanekaragaman dan Kelimpahan Arthropoda pada Perkebunan Teh 300-600 m dari Tepi Hutan di PTPN VIII Gunung Mas, Bogor
Abstrak: Pest control with synthetic pesticides causes various negative influences, on the environment, plant, or human health and safety. The concept of integrated pest control (IPC) began to be developed as an alternative. Understanding on the diversity and abundance of arthropods in an ecosystem is the basic consideration to implement the IPC system. The research is conducted to identify the diversity and abundance of arthropod in tea plantations within 300-600 m from edge of the forest in Gunung Mas PTPN VIII. Sampling was conducted from March until May 2013. The sampling location is in areas of tea plantations within 300-400, 400-500, to 500-600 m from the forest edge. Arthropod sampling method is to use insect netting, branches beating, and using pitfall trap. Observation performed 12 times with one week interval between observations. Number of arthropods obtained in the observations is 4403 individuals consisting of 18 orders and 58 families. Arthropod diversity was highest in locations 300-400 m from the forest edge. Arthropod abundance was highest at locations 400-500 m from the forest edge. The proportion of predatory arthropods obtained the highest is 52%, then 27% herbivor, detrivor 20%, and parasitoids and other insects about 1%.
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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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