Judul: Quality Analysis of River Water Around and Soil in the Mining Area of PT Berau Coal Binungan Site, East Kalimantan Province
Abstrak: Salah satu hal terpenting dalam aktivitas penambangan batubara dengan sistem tambang terbuka adalah bagaimana melakukan reklamasi lahan dan mengembalikan agar kelestarian lingkungan tetap terjaga. Reklamasi lahan pasca tambang merupakan bagian dari perencanaan dan pelaksanaan kegiatan penambangan untuk memastikan agar upaya perbaikan lahan-lahan yang terganggu oleh kegiatan pertambangan dapat dilaksanakan secara efektif dan efisien dengan mempertimbangkan karakteristik kondisi fisik, kimia, dan biologi tanah. Sampai saat ini reklamasi yang telah dilakukan diduga belum ada yang berpihak pada pembangunan kawasan pasca tambang batubara yang berkelanjutan dengan menganut prinsip memanfaatkan, melindungi dan melestarikan lingkungan. Sementara itu, pelaksanaan reklamasi yang dilakukan sampai saat ini sifatnya sekedar memenuhi tuntutan prosedur yaitu hanya menjadikan reklamasi sebagai bagian dari persyaratan pelaksanaan pertambangan batubara yang kebanyakan belum memadai. Kegiatan reklamasi ini selain ditunjukan untuk memperbaiki sifat-sifat tanah, diharapkan juga akan memperbaiki kualitas air permukaan di sekitar areal reklamasi. Oleh karena itu perlu dilakukan penelitian untuk mengetahui kondisi air dan tanah di sekitar areal daerah tersebut. Dengan penelitian ini, diharapkan menjadi acuan dalam pelaksanaan reklamasi yang berkelanjutan., Coal mining activities without reclamation will lead to environmental degradation such as change of freshwater and soil qualities. Reclamation of post mining land is part of the planning and implementation of mining activities to ensure that repairing of lands affected by mining activities can be conducted effectively and efficiently by improving the post mined soil conditions. This research was aimed to analyze the qualities of river water around and soil in the mining area of PT Berau Coal Binungan Site. Samples of river water were taken as many as 10 locations, whereas soil samples were taken from soils of land after 0, 3, 6, and 9 years of reclamation and forest soil. The results showed that some of the parameters of water such as temperature, pH, DO, Fe, Mn, oils and fats, were below the grade I Quality Standard of Government Regulation No. 82/ 2001. However, COD was above Grade III, while BOD was above grade IV of the Quality Standard. These indicates that all the water sample were not qualified as standart drinking water (grade I). Results of soil analysis indicated that physical, chemical and biological of soil properties varied both due to the increase in reclamation age and the heterogeneous nature of the soil materials. Properties including BD, infiltration, aggregate stability, organic-C, and biological properties were improved with increasing the age of reclamation approaching the properties of forest soil. Other properties including pH, CEC, exchangeable bases, base saturation, available P, available micro elements, and total S were varied due also to the heterogeneous nature of the soil material.
Keyword: Coal mining, Water quality, Soil quality

Judul: Analisis Sifat Fisik, Kimia, dan Biologi Tanah pada Lahan Reklamasi Bekas Tambang Batubara PT Berau Coal Site Binungan, Kabupaten Berau, Provinsi Kalimantan Timur
Abstrak: Soil degradation becomes the greatest problem of environmental damage due to coal mining, in particular by open pit method. Proper reclamation must be done to repair post mining land so that soil quality can be recovered approaching the original properties. To analyze the results of the reclamation process on physical, chemical, and biological soil properties changes and their development, it is necessary to study the changes of soil properties at different ages post coal mining land reclamation. This research was aimed to identify the changes of physical, chemical, and biological soil properties in relation to increased reclamation age (0, 3, 6, and 9 years old) and compared them to the nearby forest soil properties. This research was conducted in reclaimed post coal mining lands of PT Berau Coal Site Binungan, East Kalimantan Province (aged 0, 3, 6, and 9 years), and native forest. Soil analysis performed at the Laboratory of Chemical and Soil Fertility, Laboratory of Soil Physics, and Laboratory of Soil Biotechnology, Department of Soil Science and Land Resources, Faculty of Agriculture, Bogor Agricultural University. The results showed that increasing age causes changes in soil properties of reclaimed land approaching the soil properties of original land. This can be seen on the parameters such as bulk density, infiltration capacity, aluminum saturation, C-organic, total N, base saturation, Cation Exchange Capacity (CEC), total microbial and fungal, and soil respiration. It is apparent that chemical and biological soil properties on reclaimed land change relatively faster approaching the chemical and biological soil properties of the original land compared to that of physical soil properties.
Keyword: 

Judul: Invers Drazin dari Matriks Toeplitz Singular
Abstrak: Matriks Toeplitz adalah matriks yang setiap unsur pada diagonal utama bernilai sama dan setiap unsur pada subdiagonal yang bersesuaian dengan diagonal utama juga bernilai sama. Matriks singular adalah matriks yang tidak bisa ditentukan inversnya. Akan tetapi, dapat diupayakan untuk ditentukan inversnya menggunakan invers matriks yang diperumum. Invers Drazin merupakan salah satu jenis invers matriks yang diperumum. Pada karya ilmiah ini ditentukan invers Drazin dari matriks Toeplitz singular dengan menggunakan metode Leverrier Faddeev. Kemudian, ditentukan invers Drazin dari matriks Toeplitz singular yang direpresentasikan sebagai penjumlahan segitiga bawah dan segitiga atas matriks Toeplitz berdasar pada teorema Gohberg dan Semencul., Toeplitz matrix is a matrix in with element on the main diagonal has the same value and on the subdiagonal corresponding to the main diagonal also has the same value. Singular matrix is a matrix that has no inverse. However, it can be attempted to determine the inverse using a generalized inverse matrix. Inverse Drazin is a type of generalized matrix inverse. This paper discussed the inverse Drazin for a singular Toeplitz matrix using the Leverrier Faddeev method. Then, the Drazin inverse of the singular Toeplitz matrix which is represented as a sum of products of lower and upper triangular Toeplitz matrix based on Gohberg and Semencul theorem.
Keyword: inverse Drazine, singular Toeplitz matrix