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: 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: igenvalues and Eigenvectors of Tridiagonal Matrix with Non Constant and Recurrent Diagonal Entries.
Abstrak: Matriks tridiagonal adalah suatu matriks yang mempunyai entri-entri bernilai nol kecuali pada diagonal utama, di bawah diagonal utama (subdiagonal) dan di atas diagonal utama (superdiagonal). Entri pada diagonal utama tidak konstan dan berulang. Setiap entri pada matriks tridiagonal ini adalah bilangan kompleks. Dalam karya ilmiah ini, akan dibuktikan 3 teorema untuk menentukan nilai eigen dengan 2 kasus dan 1 teorema untuk menentukan vektor eigen. Teorema pertama menentukan polinomial karakteristik dari matriks tridiagonal. Polinomial karakteristik dari matriks tridiagonal tersebut digunakan untuk menentukan nilai eigen pada teorema kedua dan ketiga serta menentukan vektor eigen pada teorema keempat
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