Judul: Reklamasi lahan pascatambang timah dan tingkat perkembangan wilayah di Kabupaten Bangka
Abstrak: Tin mining industry in Bangka Regency contributes positively to the national income, and increase in Gross Regional Domestic Product (GRDP), labour availability, and economic value. The tin mining also poses negative impacts on the environment. Post-mined reclamation is expected to increase regional economic level and stimulate economic growth so that after the closure of mining activities there is no inequality in the community socio-economic aspect. The aims of the research are: (1) to assess tin post-mined land reclamation techniques for plant growth, (2) to assess the types of reclamation plants suitable to grow and have an economic benefit to the community, (3) to determine priority of the reclamation plant types suitable to grow based on the stakeholders perceptions, (4) to plan an arrangement of plant types and land reclamation techniques in the tin post-mined area, and (5) to determine the level of the community income and regional development in villages with tin mining activities in Bangka Regency. The results show that the reclamation technique that can be implemented was by providing soil ameliorants (manure or compost, top soil and rock phosphate or dolomite) and fertilizers to the tailings, and then provide MAF inoculant or planting cover crops of the leguminoseae familiy and planted with native plants or plants which suitable to grow in the such a tin postmined land conditions. Implementation of the reclamation technique resulted in an increase in land suitability classes to be S3 (marginally suitable) for rubber (Hevea brasiliensis) and S2 (moderately suitable) for sengon (Paraserianthes falcataria) and acacia (Acacia auriculiformis). Based on the stakeholder perception, rubber is the priority plant, while plant which generate economic benefit is sengon. The community income of villages around the tin mining area increased in the period of 2003-2008. At the time of mining activities, hierarchy of some villages around the mine increased but then decreased after the closure of the tin mining activities.
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Judul: Analysis of Development of Post-Coal Mining Land Reclamation Research in Indonesia
Abstrak: Pertambangan merupakan salah satu sektor yang dapat menyumbangkan devisa besar bagi negara. Komoditas pertambangan di Indonesia diklasifikasikan menjadi mineral, batu bara, serta minyak dan gas. Batu bara di Indonesia umumnya diekstrak dengan sistem penambangan terbuka yang menghilangkan ekosistem hutan beserta fungsinya. Kegiatan tersebut menyebabkan terbentuknya lahan terdegradasi sehingga dibutuhkan penerapan kegiatan revegetasi. Penelitian ini bertujuan untuk mengetahui perkembangan penelitian untuk mendukung keberhasilan reklamasi tambang batu bara di Indonesia serta mengetahui kategori penelitian yang kurang mendapat perhatian dan perlu pengembangan lebih lanjut. Penelitian dilakukan dengan mengumpulkan semua informasi yang tersedia secara online berasal dari jurnal, repository, buku dan sumber yang terkait dengan kegiatan reklamasi lahan bekas tambang batu bara. Berdasarkan hasil penelitian, kategori yang paling banyak diteliti adalah kategori kualitas tanah dan kategori pemilihan jenis tanaman dengan masing-masing 23 judul penelitian, sedangkan kategori persemaian yang paling sedikit diteliti, yaitu hanya 2 (dua) judul penelitian. Kata kunci: batu bara, jenis tanaman, reklamasi, tanah tambang, Mining is one of the sectors that can contribute large foreign exchange for the country. Mining commodities in Indonesia are classified into minerals, coal, and oil and gas. Coal in Indonesia is generally extracted by an open-pit mining system which eliminates forest ecosystems and their functions. These activities lead to the formation of degraded land so that the implementation of revegetation activities is needed. This study aims to determine the development of research to support the success of coal mine reclamation in Indonesia and to find out aspects of research that have received less attention and need further development. The research was conducted by collecting all the information available online from journals, repositories, books and sources related to land reclamation activities of former coal mines. Based on the results of the research, the most studied categories were the soil quality category and the plant species selection category with 23 research titles each, while the nursery aspect was the least studied, namely only 2 (two) research titles. Keywords: coal, mining land, reclamation, types of plants
Keyword: batu bara, jenis tanaman, reklamasi, tanah tambang, coal, mining land, reclamation, types of plants

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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