Judul: Dinamika Soliton DNA Kuintik dengan Koefisien Dispersi dan Nonlinearitas Bergantung Ruang Berdasarkan Prinsip Variasi
Abstrak: Deoxyribonucleic acid is one of the most important biomolecules in the cell and has an important function in transferring genetic information. The double helix structure in DNA is indeed very complex especially when it is related to the biological process such as DNA transcription. In the initial process of transcription, the bubbling denaturation, a process with small amplitude will keep continuing as far as the denaturation process keeps propagating along the DNA strain which then allows the denaturation of the hydrogen bond and the forming of the denaturation wave, occured. The aim of this research is to describe the mechanism of bubling denaturation in DNA with the great amplitude which is stated in the QNLS equation in which the dispersion and nonlinearity coefficient dependent spaces based on the principle of variation. The profiles examined, show the increasing of velocity of DNA strain if the dispersion effect is larger. If the nonlinearity increases, then the DNA denaturation comprises only a few of nucleotides, but does not affect the velocity of the DNA strain itself.
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Judul: Efek Damping pada Soliton DNA Kuintik Berdasarkan Prinsip Variasi
Abstrak: DNA is one of the macromolecules that has very important roles in biological system of organism. Some of the Activities of breather DNA are transcription and replication. DNA transcription that related to DNA denaturation bubble, is influenced by viscosity of medium. DNA breathing can be set by the QNLS equation with a finite set of parameters. The purpose of this research is to study the dynamics of parameters variation of damped QNLS equation that describes the influence of surrounding medium to DNA soliton. Variation parameters of the QNLS equation were obtained using the variational method, where damping is considered as a perturbation. Damping factor causes a significant reduction in amplitude and widening of DNA soliton’s wave. Damping factor has also shown the existence of the change in the number of nucleotides that are involved in the process of DNA denaturation.
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Judul: Budidaya Dan Pengelolaan Hasil Tanaman Karet Di Pekebunan Cimulang PTP XI Kecamatan Semplak, Kabupaten Bogor
Abstrak: Tanaman karet (Hevea brasiliensis) pertama kali di- usahakan oleh bangsa Portugis. Karet yang pertama datang di Indonesia ditanam di Cultuurtuin (LPTI Cimanggu) pada tahun 1876. Pada tahun 1902 perkembangan yang pesat terdapat di pulau Jawa dan selanjutnya menyebar ke Sumatera dan pulau lain, terutama di Asia Tenggara (Iskandar, 1984). Sampai tahun 1957 Indonesia masih tercatat sebagai negara produsen karet alam terbesar di dunia. Pada tahun tersebut produksi di Indonesia mencapai 695 000 ton, Malaya (Malaysia sekarang) 688 700 ton dan Thailand 133 000 ton. Tetapi pada tahun-tahun berikutnya laju peningkatan produk- si di Indonesia sangat rendah dan sebaliknya dengan Malaysia dan Thailand. Pada masa mendatang, Thailand merupakan saingan yang berat bagi Indonesia dan dapat menggeser kedudukan Indonesia sebagai produsen karet terbesar (Iskandar, 1984). Pada saat ini Indonesia merupakan produsen nomor dua setelah Malaysia. Kemunduran ini disebabkan (a) terlambat mengadakan peremajaan, (b) sebagian besar tanaman sudah tua dan bukan klon unggul, (c) situasi keamanan dan politik belum mendukung usaha peremajaan karet. Menurut data dari berbagai sumber sebagian besar produksi karet Indonesia pada dekade tujuh puluhan sebesar 23.9% dari produksi dunia, sedangkan Malaysia 43.9% (Iskandar, 1984)..
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