Judul: Pengaruh Pirit Terhadap Sifat Kimia Tanah Serta Produksi Tanaman Kelapa Sawit (E. guineensis)
Abstrak: Development of oil palm plantation areas in Indonesia has significantly increased every years. This makes the development leads to marginal lands, like the lands acid sulfate soil which has sulfidic material. The expansion of the plantation into the marginal lands, is not an expected alternative, but the suitable lands were limited. Oxidation of pyritic material in aerobic condition will produce sulfuric acid and mineral jarosit with extreme acidity that can prohibit plant growth. The conditions is obtained due to land reclaimation through establishment of drainage facilities. On the other hand, large amounts of plant nutrients washed out from the lands. The leaching are more conducive in high acidity drainage water. Ultimately this processes are reducing soil fertility with low soil pH as well. The study aims to determine the effect of different depths of pyritic material and pyrite oxidation on soil chemical properties and oil palm production. Location of soil sampling and observations conducted in the oil palm plantation Business Unit Bentayan and Betung Krawo, PT Perkebunan Nusantara VII (Persero), South Sumatra. Analysis of soil samples carried out at the Laboratory of Department of Soil Science and Land Resources, Faculty of Agriculture, Bogor Agricultural University. Observations focused on the depth pyritic material at <30 cm, 30-60 cm, and > 60 cm, and not containing pyritic material. Special observation conducted on soil chemical properties at the soil with and without oxidation. The results show that the content of pyrite at depths <30 cm have a significant effect on increasing soil acidity and exchangeable aluminum content (Al-dd), and reduced levels of N-total nutrients, potassium (K) and production of fresh tube fruits. Oxidation pyrite also gives a tendency of decreased levels of available nutrients phosphorus (P), calcium (Ca), magnesium (Mg), and base saturation. Pyritic lands which have undergone an oxidation process tended to decrease fertility.
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Judul: Pengaruh pemberian bahan humat dan zeolit terhadap sifat-sifat kimia tanah dan kadar unsur pada kelapa sawit (Elaeis guineensis jacq.)
Abstrak: Indonesian oil palm productivity is still relatively low, which among others caused by factors that are still lacking good management and the nature of matter and soil characteristics in oil palm plantations. Land planted with oil palms generally have cation exchange capacity (CEC) and soil organic matter content is low, so the ability of soil nutrients and low water. One attempt to fix the problem on the ground done by setting the humic substance. This research was conducted with the aim to determine the effect of humic substance with zeolite carriers to changes in soil chemical properties and nutrient content in oil palm plantations. The research was conducted in oil palm plantations PTPN VIII, Cimulang, Rancabungur district, Bogor regency. Experiments using completely randomized factorial design with two factors. Provision of humic substance as the first factor, with a dose of humic materials: 0 liters / ha (H0), 5 liters / ha (H1), 10 liters / ha (H2), 15 liters / ha (H3), while the zeolite is used as administered dose carrier: 0 kg / liter humic substance (Z0), 10 kg / liter humic substance (Z1), and 20 kg / liter humic substance (Z2).
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Judul: Formulasi Algoritme Operasi Grup Jacobian Kurva Hyperelliptic ...
Abstrak: Dalam geometri aljabar, kurva hyperelliptic merupakan bentuk umum dari kurva elliptic. Kurva ini apabila dikenakan pada suatu lapangan berhingga akan membentuk suatu grup siklik. Pada kriptografi, khususnya enkripsi kunci publik, grup siklik yang dibangkitkan oleh kurva elliptic sudah banyak diteliti. Bahkan untuk kurva ini sudah memiliki standar oleh National Institute of Standard and Technology (NIST) Amerika. Sedangkan, untuk grup yang dibangkitkan oleh kurva hyperelliptic masih memiliki kekurangan dalam hal komputasinya. Tujuan dari penelitian ini adalah mengkonstruksi suatu lapangan berhingga pada , memilih kurva hyperelliptic atas lapangan hingga yang memenuhi kriteria keamanan untuk kriptografi, dan membuat formulasi operasi grup kurva hyperelliptic menggunakan algoritme Cantor. Dalam merekonstruksi lapangan hingga, terlebih dahulu tentukan dimensi dari lapangan hingga tersebut dan polinomial tak-teruraikan. Kemudian dipilih kurva hyperelliptic atas lapangan tersebut. Pada penelitian ini, kurva yang dipilih adalah = + + dengan lapangan hingga . Berdasarkan kurva yang dipilih, akan dibentuk suatu operasi grup dengan menggunakan algoritme Cantor, sehingga menjadi lebih aritmatik. Eksplorasi kurva hiperelliptic dilakukan untuk mengetahui keamanan dari kurva yang dipilih. Dengan menyusun algoritme operasi grup dari kurva yang dipilih, diperoleh perhitungan yang lebih aritmatik dan dapat diimplementasikan pada kriptografi kunci publik. Dari segi keamanan kurva telah memenuhi standar sehingga tahan terhadap serangan-serangan seperti Poligh-Hellman, Polard- , ataupun Frey-Ruck secara teorema.
Keyword: algoritme Cantor, kriptografi, kunci publik, kurva hyperelliptic, operasi grup