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: Konsentrasi Logam Berat Timbal (Pb) dan Tembaga (Cu) pada Sedimen dan Air di Perairan Pelabuhan Klidang Lor, Batang, Jawa Tengah
Abstrak: Lead (Pb) and copper (Cu) are toxic and persistance pollutants. The information on these heavy metals water quality in the Port Klidang Lor is still limited, whereas the activities of fishing port have been growing fast. The objective of this study was to determine distribution the concentration of lead (Pb) and copper (Cu) in sediments and water in the Klidang Lor coast of, Batang, Central Java. Sediment and water samples were taken from 11 stations in April 2014. The analysis of heavy metals was performed using Atomic Absorption Spectrometry (AAS) with following APHA procedure (ed 22 , 2012, 3111 – B). Dissolved Pb and Cu concentrations varried in the water column between 0.003-0.006 mg/L and 0.007-0.008 mg/L lower than the these of threshold limit by ministry of environment. The concentration of Pb in sediment ranged between 12.73- 21.07 mg/kg and the concentration of Cu in sediment ranged from 7.73-27.21 mg/kg lower than the these of threshold limit by Dutch Quality Standard For Metals in Sediments. Source of the heavy metal concentration in these waters were possibly to be derrived from an oil spill of the vessel, the activity of shipyards, settlement activity in surrounding port. Variations of heavy metal concentration are also affected by the size of particles in the sediment and organic content.
Keyword: Bogor Agricultural University (IPB), Copper, lead, Sediment, Heavy metal, Klidang Lor-Batang

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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