Judul: Konsentrasi Logam Berat Timbal (Pb) pada Air, Sedimen, dan Rumput Laut Sargassum polycystum di Perairan Pulau Pari, Kepulauan Seribu
Abstrak: The aim of this research was to analyze the lead (Pb) concentration in water, sediment, and Sargassum polycystum at Pari Island, Seribu Islands. Sample of water, sediment, and Sargassum polycystum were collected in August 2014 from Pari Island. The heavy metal concentrations were then analyzed by Atomic Absorption Spectrometry methods. The results showed that Pb concentrations in water, sediment, and Sargassum polycystum was 0,009 - 0,015 mg/l, 44,72 - 50,01 mg/kg and 16,89 - 17,59 mg/kg, respectively. Lead concentrations in water exceeded its normal concentration in natural waters. However, the concentration of Pb in sediment was still in the range of non-polluted waters. The indications of Pb in this waters showed an increasing trend and accumulatic in Sargassum polycystum.
Keyword: Bogor Agricultural University (IPB), Pari Island, Sargassum polycystum, Sediment, Water, Lead

Judul: Sebaran Logam Berat (Cd, Cu, Hg, Pb) pada Sedimen di Perairan Pesisir Kabupaten Tangerang
Abstrak: Pollution of coastal waters caused by Tangerang Regency industrial, domestic, and farmers. Dangerous pollution parameters such as metal cadmium (Cd), copper (Cu), mercury (Hg) and lead (Pb). The concentration of heavy metals in sediment suspended in the water will then settle and accumulate in sediment. This study was conducted in April and August 2013 in the coastal area of Tangerang, Banten. This sampling of water and sediment quality. Method of measurement of heavy metals is ICP and AAS. Analysis of heavy metals is descriptive and statistical. Spearman correlation test is to determine relationship between concentration of heavy metals with grain size particle and total organic carbon. Distribution of heavy metals in sediments varies spatially. The value of the metal content of Hg as a whole has exceeded the quality standard that Hg pollution. The Spearman correlation showed that their is no relationship between heavy metal content with grain size particle (dominated by silt) and total organic carbon showed (P> 0.05).
Keyword: Bogor Agricultural University (IPB), total organic carbon., sediment, grain size particle, Pb element, Hg, Cu, Cd

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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