Judul: Distribution of Microplastic in Water Column Citarum River, Jawa Barat Province.
Abstrak: Semakin meningkatnya asupan limbah dari berbagai macam kegiatan di sepanjang aliran sungai diduga juga menyebabkan meningkatnya limbah plastik, yang kemudian dapat berakumulasi sebagai mikroplastik baik di dalam tubuh biota maupun manusia. Penelitian ini bertujuan untuk membandingkan keberadaan mikroplastik pada air di bagian hulu, tengah, dan hilir Sungai Citarum, Jawa Barat berdasarkan tipe, warna dan kelimpahan mikroplastik. Analisis secara statistik menggunakan Uji Kruskal Wallis dan Uji Mann Whitney. Data dianalisis menggunakan perangkat lunak MS. Excel 2010 dan SPSS 15. Kelimpahan mikroplastik di Sungai Citarum pada Stasiun Hilir lebih tinggi dibandingkan dengan kelimpahan mikroplastik pada Stasiun Tengah dan Stasiun Hulu. Mikroplastik pada Stasiun Hulu, Stasiun Tengah, dan Stasiun Hilir didominasi oleh warna transparan. Kelimpahan mikroplastik pada Stasiun Hulu, Stasiun Tengah, dan Stasiun Hilir tertinggi yaitu tipe film., The increasing intake of waste from various activities along the river flow is also thought to have caused an increase in plastic waste, which can then accumulate as microplastics in both biota and human bodies. This research aims is to compare the presence of microplastics in the upstream, middle, and downstream of the Citarum River waters, West Java based on type, color and abundance of microplastics. Statistical analysis using Kruskal-Wallis test and Mann Whitney test. Data were analyzed using MS software Excel 2010 and SPSS 15. The abundance of microplastics in the Citarum River at the Downstream Station was higher than the abundance of microplastics at the Central Station and the Upstream Station. Microplastics at the Upstream Station, Middle Station, and Downstream Station are dominated by transparent colors. The highest abundance of microplastics at the Upstream Station, Middle Station, and Downstream Station was film type.
Keyword: itarum River, microplastic, waters

Judul: Kelimpahan Mikroplastik pada Air di Sungai Cisadane, Provinsi Jawa Barat-Banten
Abstrak: Sungai Cisadane berada di Pulau Jawa serta mengalir di daerah Jawa Barat dan Banten, melintasi beberapa kawasan yang berpenduduk padat dan memiliki akitifitas yang tinggi. Akibat banyaknya aktivitas masyarakat tersebut menghasilkan buangan sampah baik organik maupun anorganik. Sampah plastik merupakan salah satu jenis sampah yang menjadi perhatian para pemerhati lingkungan dibeberapa tahun terakhir ini, karena memiliki dampak buruk yang signifikan di perairan. Mikroplastik didefinisikan sebagai partikel plastik dengan ukuran < 5 mm. Penelitian ini bertujuan untuk mendeskripsikan kelimpahan, dan ukuran mikroplastik di Sungai Cisadane yang melewati wilayah Jawa Barat dan Banten dari hulu sampai hilir, pada musim yang berbeda. Data dianalisis menggunakan perangkat lunak MS. Excel 2013 dan SPSS 15. Pada SPSS 15 data dianalisis secara statistik menggunakan uji Kruskal-Wallis dan uji Mann-Whitney. Rata-rata kelimpahan mikroplastik sungai Cisadane berkisar 181-2217 partikel/m³ dan ditemukan paling banyak pada bulan Agustus dan stasiun hilir. Jenis mikroplastik yang banyak ditemukan yaitu film dan warna mikroplastik yang banyak ditemukan yaitu hitam. Kelompok ukuran mikroplastik didominasi dengan ukuran 20-40μ. Rata-rata kelimpahan mikroplastik Stasiun hilir lebih banyak dibandingkan Stasiun lain. Kelimpahan mikroplasrik bulan Agustus 2019 memiliki nilai yang lebih banyak bila dibandingkan dengan kelimpahan pada bulan lain., The Cisadane River is located on the island of Java and flows in West Java and Banten, crossing several areas that are densely populated and have high activity. As a result of the many activities of the community, it produces both organic and nonorganic waste. Plastic waste is one type of waste that has become a concern for environmentalists in recent years, because it has a significant adverse impact on waters. Microplastics are defined as plastic particles with a size <5 mm. This study aims to describe the abundance, and size of microplastics in the Cisadane River which passes through West Java and Banten from upstream to downstream, in different seasons. Data were analyzed using MS. Excel 2013 and SPSS 15. In SPSS 15, data were statistically analyzed using the Kruskal-Wallis test and the Mann-Whitney test. The average abundance of microplastics in the Cisadane River ranged from 181-2217 particles/m³ and was found most in August and downstream stations. The type of microplastics found is film and the color of microplastics found is black. The microplastic size group is dominated by the size of 20-40μ. The average abundance of microplastics downstream stations is more than other stations. The abundance of microplastics in August 2019 has a higher value when compared to the abundance in other months.
Keyword: air, mikroplastik, Sungai Cisadane

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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