Judul: Kandungan  Logam Berat Pb, Hg, Cd pada Ikan Kurisi Nemipterus japonicus (Bloch, 1791)  di Perairan Pulau Bacan, Maluku Utara
Abstrak: Pulau Bacan merupakan wilayah yang mendapatkan pengaruh dari kegiatan antropogenik, seperti pertambangan dan industri lain berbasis logam. Kandungan logam berat di lingkungan yang berpotensi terakumulasi ke dalam tubuh organisme, seperti ikan kurisi (Nemipterus japonicus). Penelitian ini bertujuan menganalisis bioakumulasi logam berat Pb, Hg, Cd pada daging, insang, dan hati ikan kurisi (Nemipterus japonicus Bloch, 1791) yang berada di perairan Pulau Bacan, Maluku Utara. Pengambilan sampel kualitas air dan ikan kurisi dilakukan di tiga stasiun untuk mengetahui kualitas air dan kandungan logam berat di perairan dan ikan. Analisis kandungan logam berat dilakukan dengan menggunakan AAS (Atomic Absorption Spectrophotometer). Kandungan logam berat Pb, Hg, dan Cd di perairan telah melampaui baku mutu. Kandungan logam berat Pb, Hg, Cd pada ikan kurisi tertinggi pada hati. Bioakumulasi logam berat Pb, Hg, dan Cd pada daging ikan kurisi termasuk akumulasi yang rendah dan sedang., Bacan Island is an area affected by anthropogenic activities such as mining and other metal-based industries. The content of heavy metals in the environment has the potential to accumulate in body organisms, such as threadfin bream fish (Nemipterus japonicus). This study aims to analyze the bioaccumulation of heavy metals Pb, Hg and Cd in the meat, gills and liver of the threadfin bream fish (Nemipterus japonicus Bloch, 1791) in the waters of Bacan Island, North Maluku. Sampling of water quality and threadfin bream fish was carried out at three stations to determine water quality and heavy metal content in the waters and fish. Analysis of heavy metal content was using an AAS (Atomic Absorption Spectrophotometer). The content of heavy metals Pb, Hg and Cd exceeded the quality standards in waters. The content of heavy metals Pb, Hg, Cd in threadfin bream fish was highest in the liver. Bioaccumulation of heavy metals Pb, Hg, and Cd in threadfin bream fish meat includes low and moderate accumulation.
Keyword: : Bioaccumulation, water quality, quality standards

Judul: Heavy Metal Content of Hg, Pb, and Cd in Skipjack Tuna Katsuwonus pelamis (Linnaeus, 1758) in Waters of Bacan Island, North Maluku
Abstrak: Pulau Bacan memiliki sumberdaya perikanan yang sangat potensial. Namun, di Pulau Bacan berlangsung aktivitas antropogenik seperti pertambangan, pertanian, perkebunan, dan pelabuhan yang berpotensi menimbulkan pencemaran logam berat di perairan. Penelitian ini bertujuan menganalisis tingkat bioakumulasi logam berat Hg, Pb, dan Cd pada ikan cakalang (Katsuwonus pelamis Linnaeus, 1758) di perairan Pulau Bacan, Halmahera Selatan, Maluku Utara. Pengambilan sampel air dan pengukuran parameter kualitas air serta pengambilan bagian daging, insang, dan hati ikan cakalang berlangsung pada bulan Februari 2022. Pada air, kandungan logam berat Hg, Pb, dan Cd telah melampaui baku mutu. Kandungan logam berat Hg, Pb, dan Cd tertinggi pada ikan cakalang ditemukan pada hati, sedangkan terendah pada daging. Pada daging ikan cakalang, tingkat akumulasi Hg, Pb, dan Cd tergolong rendah., Bacan Island has a high potential of fishery resources. However, anthropogenic activities such as mining, agriculture, and ports taking place on Bacan Island cause heavy metal pollution in the waters. This study aimed to analyze the bioaccumulation level of heavy metals such as Hg, Pb, and Cd in skipjack tuna (Katsuwonus pelamis Linnaeus, 1758) in the waters of Bacan Island, South Halmahera, North Maluku. Water sampling, measurement of water quality parameters and fish sampling was conducted in February 2022. In the water, the heavy metals concentration of Hg, Pb, and Cd has exceeded the quality standard. The highest concentration of Hg, Pb, and Cd was found in the liver, while the lowest was in the muscle. In skipjack tuna muscle, the accumulation level of Hg, Pb, and Cd is low.
Keyword: Bacan Island, heavy metal, skipjack tuna

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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