Judul: Keragaan Sifat Kimia Tanah di Bawah Vegetasi Mangrove dan Hubungannya dengan Air Tanah Serta Perkembangan Akar dari Beberapa Zona Hutan MAngrove Banyuwedang Kabupaten Buleleng, Bali
Abstrak: Penelitian bertujuan untuk mempelajari dan mengetahui perbedaan sifat kimia tanah di bawah vegetasi mangrove dan hubungannya dengan sifat kimia air tanah dan perkembangan akarnya. Penelitian telah dilakukan pada beberapa zona mangrove yaitu Rhizophora, Ceriops, Avicennia dan Lumnitzera di hutan mangrove Banyuwedang, Kabupaten Buleleng, Bali. Pada masing-masing zona diambil contoh tanah pada lapisan atas (0-30 cm) dan lapisan bawah (30-60 cm) yang dilakukan secara komposit, dan kemudian diambil contoh air tanah serta akar mangrovenya. Untuk melihat keeratan hubungan beberapa sifat kimia tanah, air tanah dan akar mangrove dilakukan melalui Analisis Regresi Berganda.
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Judul: Hubungan Sifat Tanah dan Tipe Vegetasi Mangrove di Desa Blanakan, Kabupaten Subang.
Abstrak: Mangrove ecosystem is a typical marine tropics and subtropics with a very important role for the balance of nature. However, currently the target of exploitation of mangrove forests due to the demands of development which focuses on economic interests. More than a half of the mangrove forest area in Indonesia in a bad damaged state, around the North Coast of Java, has long been eroded by the needs of its population to the land. Mangrove forests that relatively in good condition on the north coast of Java is in the village Blanakan, so the mangroves in the area need to be in the preserve. This study aims to determine the nature and characteristics of soil that affect the growth of mangrove land the village and to know the relationship of the soil properties with different types of mangrove vegetation that grows in the village Blanakan. There are 4 zones studied based on the type of vegetation growing in these locations. Zone 1 (BSR1) with vegetation Avicennia marina, zone 2 (BSR2) with Rhizophora mucronata vegetation, zone 3 (BSR3) with vegetation Jeruju, and zone 4 (BSR4) with vegetation Sonneratia acida. The sample of soil that have been researched are morphological and chemical properties. All of soil conditions are not significantly different by morphology. Those all zones are type Hydraquent soil. Chemical properties which have an influence on mangrove vegetation difference are the Electrical Conductivity (DHL/EC), water content at field condition, percentage saturation of the cations, the percentage of ESP, and SAR values, and value of soil. The DHL/EC, the percentage of ESP, and SAR values show the influence of sea water. Zone 1 had the soil more ripe than zone 2, 3, and 4. Cation saturation of each zone has its own characteristics. A base saturation zone was dominated by sodium saturation and followed by increasing the depth of soil. Zone 1 showed many salt-free and the salt free content increased from the upper to the lower layer. Base saturation in zone 2, between the top layer of soil is different from the middle layer and bottom layer. The top layer of soil in zone 2 was dominated by the saturation of magnesium, but in the middle layer and bottom layer was dominated by sodium saturation. Sodium saturation in zone 2 further decreased, this suggest that salt-free in this zone was diminishing compared to zone 1. In zone 3 and zone 4, there are no free salts and base saturation was dominated by magnesium, and also increased of addition calcium.
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Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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