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 Metals Content (Pb, Hg, Cd) in Crescent Grunter (Terapon jarbua, Forsskål 1775) in Bacan Island Waters
Abstrak: Pulau Bacan memiliki potensi perikanan dan pariwisata yang tinggi. Kegiatan pariwisata dan kehidupan masyarakat sekitar berpotensi menjadi penyumbang cemaran logam berat ke lingkungan perairan tersebut. Salah satu potensi perikanan dengan nilai ekonomis penting yang terdapat di pulau ini adalah ikan kerong-kerong yang banyak dimanfaatkan sebagai bahan pangan baik dalam kondisi segar maupun olahan ikan asin-kering. Penelitian ini bertujuan menganalisis tingkat bioakumulasi logam berat Pb, Hg, dan Cd pada organ hati, insang, dan daging ikan kerong-kerong (Terapon jarbua, Forsskål 1775) di Perairan Pulau Bacan, Maluku Utara. Pengambilan sampel air, pengukuran kualitas air, serta pengambilan organ hati, insang, dan daging pada ikan kerong-kerong dilakukan pada bulan Februari 2022. Berdasarkan hasil anlisis, nilai kandungan logam berat Pb, Hg, dan Cd pada air telah melampaui baku mutu PP RI No. 22 tahun 2021 dan kandungan logam berat Pb pada hati ikan kerong-kerong ditemukan dalam konsentrasi tertinggi. Biokonsentrasi logam berat tergolong akumulasi rendah, kecuali Pb pada organ hati termasuk akumulasi sedang., Bacan Island has high fishery and tourism potential. Tourism activities and the life of the surrounding community have the potential to contribute to heavy metal contamination in the aquatic environment. One of the fishery potentials with important economic value found on this island is kerong-kerong fish which is widely used as a food ingredient both in fresh condition and processed salt-dried fish. This study aims to analyze the level of bioaccumulation of heavy metals Pb, Hg, and Cd in the liver, gills, and meat of crescent grunter (Terapon jarbua, Forsskål 1775) in Bacan Island waters, North Maluku. Sampling of water, measurement of water quality, as well as harvesting of liver, gills, and meat from crescent grunter was carried out in February 2022. Based on the results of the analysis, the values for the heavy metal content of Pb, Hg and Cd in water exceeded PP RI quality standards No. 22 of 2021 and the content of the heavy metal Pb in the liver of clam fish was found to be in the highest concentration. Bioconcentration of heavy metals is classified as low accumulation, except for Pb in the liver which is classified as moderate accumulation.
Keyword: Bacan Island, crescent grunter, heavy metals

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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