Judul: Pencemaran Sampah Padat di Sungai Citarum, Provinsi Jawa Barat
Abstrak: Sungai Citarum merupakan salah satu sungai besar yang melintas di Provinsi Jawa Barat yang dimanfaatkan oleh masyarakat untuk berbagai keperluan, namun kondisi sungai pada beberapa lokasi mengalami pencemaran sampah padat. Tujuan penelitian ini untuk menganalisis kelimpahan dan komposisi sampah padat yang ditemukan di permukaan perairan serta menentukan hubungan antara sebaran sampah padat, curah hujan, dan debit air pada Sungai Citarum, Jawa Barat. Pengambilan contoh dilakukan pada lima titik stasiun pada bulan April hingga Juni dan bulan Agustus hingga November 2021. Sampah padat yang ditemukan pada Sungai Citarum adalah tipe sampah organik dan anorganik. Sampah organik merupakan tipe sampah yang mendominasi pada setiap lokasi. Kelimpahan sampah padat tertinggi di Sungai Citarum berasal dari bagian hulu, terutama wilayah perkotaan. Kelimpahan sampah padat relatif sama pada pagi, siang, dan sore hari. Curah hujan tidak berpengaruh terhadap kelimpahan sampah padat, sementara debit memiliki pengaruh yang lemah., The Citarum River is one of the major rivers that crosses West Java Province which is used by the community for various purposes, however, the condition of the river in several locations is polluted by solid waste. The purpose of this study was to analyze the abundance and composition of solid waste found on the surface of the waters and to determine the relationship between the distribution of solid waste, rainfall and water discharge in the Citarum River, West Java. Sampling was carried out at five station points from April to June and August to November 2021. The solid waste found in the Citarum River is a type of organic and inorganic waste. Organic waste is a type of waste that dominates at each location. The highest abundance of solid waste in the Citarum River comes from the upstream, especially urban areas. The abundance of solid waste is relatively the same in the morning, afternoon and evening. Rainfall has no effect on the abundance of solid waste, while discharge has a weak effect.
Keyword: kelimpahan, komposisi, sampah padat, Sungai Citarum

Judul: The Characteristics of Types of Plastic Packaging Waste in the Upstream Segment of the Citarum River, Bandung, West Java
Abstrak: Sungai Citarum merupakan salah satu sungai terbesar di Jawa Barat yang memiliki banyak fungsi, namun memiliki permasalahan baik dalam kualitas air, pencemaran logam berat, juga pencemaran sampah. Tujuan penelitian ini untuk mengidentifikasi dan menganalisis karakteristik jenis sampah plastik kemasan di segmen hulu Sungai Citarum (hilir Sungai Cikapundung dan Nanjung), Bandung, Jawa Barat serta dampaknya ke perairan. Pengambilan contoh dilakukan di hilir Sungai Cikapundung, Kecamatan Bojongsoang dan Jembatan Nanjung, Desa Nanjung, pada bulan April hingga November 2021. Sampel sampah plastik kemasan dianalisis berdasarkan bobot dan kelimpahannya berdasarkan jenis plastiknya. Uji statistik Mann-Whitney digunakan untuk mengetahui beda nyata sampah kemasan yang ditemukan antara kedua stasiun dan Uji Kruskal Wallis untuk mengetahui pengaruh waktu pengambilan contoh. Hasil yang diperoleh menunjukkan jenis sampah plastik kemasan pada kedua stasiun didominasi oleh jenis PP (Polypropylene) dan jenis lainnya. Selain itu, jenis PET (Polyethylene Terephthalate) juga dominan ditemukan pada Stasiun Cikapundung, serta jenis PS (Polystyrene) pada Stasiun Nanjung. Sampah plastik tersebut bersifat toksik dan karsinogenik yang akan menurunkan kualitas perairan serta berbahaya bagi biota perairan., Citarum River is one of the largest rivers in West Java which has many functions, but has problems both in water quality, heavy metal pollution, and garbage pollution. The purpose of this study was to identify and analyze the characteristics of the types of plastic packaging waste in the upstream segment of the Citarum River (downstream of the Cikapundung and Nanjung Rivers), Bandung, West Java and their impact on the waters. Sampling was carried out in the downstream of the Cikapundung River, Bojongsoang District and Nanjung Bridge, Nanjung Village, from April to November 2021. Samples of plastic packaging waste were analyzed based on their weight and abundance based on the type of plastic. The Mann-Whitney statistical test was used to determine the significant difference in packaging waste found between the two stations and the Kruskal Wallis test to determine the effect of sampling time. The results obtained show that the type of plastic packaging waste at both stations is dominated by PP (Polypropylene) other types. Furthermore, the type of PET (Polyethylene Terephthalate) is also dominantly found at Cikapundung Station, and PS (Polystyrene) at Nanjung Station. The plastic waste is toxic and carcinogenic which will reduce water quality and be harmful to aquatic biota.
Keyword: plastic packaging waste, rivers pollution, toxic compounds, types of plastic

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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