Judul: Analysis of the heavy metal Pb and Fe content of  susuh kura (Sulcospira testudinaria) in rivers in Cinangka Village, Bogor Regency
Abstrak: Desa Cinangka merupakan daerah yang tercemar oleh logam berat yang disebabkan oleh kegiatan pembakaran atau peleburan aki bekas. Kualitas logam berat yang terdapat pada sungai di Desa Cinangka akan mempengaruhi kandungan logam berat yang terdapat pada keong. Penelitian mengenai analisis kandungan logam berat terhadap keong susuh kura (Sulcospira testudinaria) di Sungai Desa Cinangka masih sangat minim. Penelitian ini bertujuan untuk menganalisis tingkat bioakumulasi logam Pb dan Fe pada keong susuh kura (Sulcospira testudinaria) di Sungai Desa Cinangka Kabupaten Bogor. Kandungan logam berat Pb dan Fe pada air berkisar antara 0,0497 – 4,1748. Kandungan logam berat Pb dan Fe pada keong susuh kura berkisar antara 10,82 – 3364,62. Bioakumulasi logam berat Pb dan Fe pada keong susuh kura tergolong dalam akumulasi sedang. Hasil meta-analisis menunjukkan bahwa tidak terdapat perbedaan yang signifikan antara rata-rata kandungan logam berat Pb dan Fe pada keong susuh kura dari beberapa negara. Logam berat dapat memengaruhi organisme perairan yang terakumulasi dalam beberapa organ dan dapat memengaruhi kelangsungan hidup dan pertumbuhan, Cinangka Village is an area polluted by heavy metals caused by the burning or smelting of used batteries. The quality of heavy metals found in the river in Cinangka Village will affect the heavy metal content found in snails. Research on the analysis of heavy metal content in snails (Sulcospira testudinaria) in the Cinangka Village River is still very minimal. This study aims to analyze the level of bioaccumulation of Pb and Fe metals in snails (Sulcospira testudinaria) in the Cinangka Village River, Bogor Regency. The content of heavy metals Pb and Fe in water ranged from 0,0497 – 4,1748. The content of Pb and Fe heavy metals in snails ranged from 10,82 – 3364,62. Bioaccumulation of heavy metals Pb and Fe in snails is classified as moderate accumulation. The results of the meta-analysis showed that there was no significant difference between the average content of heavy metals Pb and Fe in snails from several countries. Heavy metals can affect aquatic organisms that accumulate in several organs and can affect survival and growth
Keyword: Logam berat, heavy metal, bioakumulasi, keong susuh kura, bioaccumulation, snail

Judul: Heavy Metals Residue of Pb and Fe in Water and  Sediment in River of Cinangka Village, Bogor
Abstrak: DANDY RISWANDI. Kandungan Logam Berat Pb dan Fe pada Air dan Sedimen di Sungai Desa Cinangka, Bogor. Dibimbing oleh SIGID HARIYADI dan ETTY RIANI. Limbah daur ulang aki bekas mengandung logam berat yang bisa mengganggu kesehatan manusia dan biota. Penelitian kandungan logam berat pada air dan sedimen di Sungai Desa Cinangka, Bogor belum pernah dilakukan. Penelitian ini bertujuan menganalisis kandungan logam berat Pb dan Fe pada air dan sedimen di Sungai Desa Cinangka, Kabupaten Bogor berdasarkan perbandingan dengan peraturan yang sudah ditetapkan. Penelitian dilaksanakan pada September 2023 hingga Juni 2024 Analisis logam berat pada air menggunakan metode AAS (Atomic Absorption Spectrofotometry). Analisis logam berat pada sedimen menggunakan XRF (X-Ray Fluoresence). Kandungan logam berat Pb dan Fe pada air dan sedimen di Sungai Desa Cinangka melebihi baku mutu yang sudah ditetapkan, DANDY RISWANDI. Heavy Metals Residue of Pb and Fe in Water and Sediment in River of Cinangka Village, Bogor. Supervised by SIGID HARIYADI and ETTY RIANI. Used battery recycling waste contains heavy metals which can harm human health and biota. Research on heavy metal residue in water and sediment in Cinangka Village, Bogor Regency has never been carried out. This research aims to analyze the residue of heavy metals Pb and Fe in water and sediment in the Cinangka Village River, Bogor Regency based on comparison with established regulations. The research was carried out from September 2023 to June 2024. Analysis of heavy metals in water using the AAS (Atomic Absorption Spectrofotometry) method. Analysis of heavy metals in sediment using XRF (X- Ray Fluoresence). The residue of heavy metals Pb and Fe in the water and sediment in the Cinangka Village River exceeds the established quality standards
Keyword: air, sedimen, sungai, besi, timbal

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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