Judul: Respon Pertumbuhan Bibit Sengon Buto pada Media Tailing PT Antam Pongkor dengan Penambahan Arang Tempurung Kelapa dan Bokashi Pupuk Kandang
Abstrak: The activity of mining could have a negative impacts for the environment if the waste it generates are not processed properly. The impact of negatives one of them is to produce the waste from gold mining activities and containing several nutrient (Tailing). Tailing is a mineral composite/heavy metal from gold mining activities. It has sandy texture and low nutrient elements. The one of ways for manage tailing is revegetation on tailing medium. Revegetation activities is one of vegetative technique that can be applied, one of them with adding of coconut shell charcoal and bokashi manure in sengon buto seedlings (Enterolobium cyclocarpum Griseb.). E. cyclocarpum is a fast growing species and one of species that have recommended for developing on land revegetation post mining with cheaper cost and also have good prospect and have high adaptability on various kinds of soil. The addition of coconut shell charcoal and bokashi manure expected to increase the quality of tailing as a growing medium in order to increase growth of E. cyclocarpum. Research conducted in the Silviculture greenhouse and forest of influence laboratory Faculty of Forestry IPB, with the location of tailing sampling conducted at PT Antam UBPE Pongkor and nutrient analysis conducted in Department of Soil Science and Land Resources laboratory Faculty of Agriculture IPB. This research uses an experimental method with a completely randomized design (CRD) factorial pattern, the first factor is coconut shell charcoal and the second factor is bokashi manure. Each treatment was repeated as many as 3 repetition. This research is finished during 3 months. The result of this research showed that the addition of coconut shell charcoal with dosage 10% and bokashi manure with dosage 60 g into tailing medium can increase value of the growth of E. cyclocarpum seedlings. and able to improve nutrient availability in the tailing medium. The addition of coconut shell charcoal and bokashi manure is the best treatment combination that able to improve nutrients availability at tailing.The activity of mining could have a negative impacts for the environment if the waste it generates are not processed properly. The impact of negatives one of them is to produce the waste from gold mining activities and containing several nutrient (Tailing). Tailing is a mineral composite/heavy metal from gold mining activities. It has sandy texture and low nutrient elements. The one of ways for manage tailing is revegetation on tailing medium. Revegetation activities is one of vegetative technique that can be applied, one of them with adding of coconut shell charcoal and bokashi manure in sengon buto seedlings (Enterolobium cyclocarpum Griseb.). E. cyclocarpum is a fast growing species and one of species that have recommended for developing on land revegetation post mining with cheaper cost and also have good prospect and have high adaptability on various kinds of soil. The addition of coconut shell charcoal and bokashi manure expected to increase the quality of tailing as a growing medium in order to increase growth of E. cyclocarpum. Research conducted in the Silviculture greenhouse and forest of influence laboratory Faculty of Forestry IPB, with the location of tailing sampling
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Judul: Pertumbuhan semai nyatoh (Palaquium spp.) pada media tailing PT. Antam Unit Bisnis Pongkor dengan penambahan arang tempurung kelapa dan pupuk kompos bokashi
Abstrak: Limbah tambang emas berupa tailing merupakan salah satu limbah utama yang bersifat toksik terhadap lingkungan karena tingkat kemasaman tanah yang tinggi sehingga dapat merusak kesuburan tanah dan vegetasi lokal akibat dari keracunan dan kontaminasi rantai makanan. Sifat tailing yang demikian menimbulkan masalah dalam kegiatan revegetasi, sehingga perlu dilakukan upaya untuk perbaikan lahan dengan cara penambahan arang tempurung kelapa dan pupuk kompos bokashi sebelum dilakukannya upaya revegetasi. Arang tempurung kelapa dan pupuk kompos bokashi mampu memperbaiki kondisi tanah yang miskin hara serta sebagai sumber unsur hara dan mikroba untuk kesuburan tanah. Selain upaya perbaikan lahan yang dilakukan perlu dilakukan pemilihan jenis tanaman yang tepat. Nyatoh (Palaquium spp.) merupakan jenis tanaman lokal Indonesia yang dapat direkomendasikan untuk dikembangkan dalam upaya revegetasi lahan pasca tambang. Hasil penelitian ini dapat disimpulkan bahwa respon pertumbuhan semai nyatoh pada media tailing dengan penambahan arang tempurung kelapa, pupuk kompos bokashi, dan campuran antara arang tempurung kelapa dan pupuk kompos bokashi mampu meningkatkan pertumbuhan tinggi, diameter dan biomassa akar pada dosis tertentu. Dosis terbaik terhadap pertumbuhan tinggi semai nyatoh dari penambahan dosis arang tempurung kelapa dan pupuk kompos bokashi adalah sebesar 75 g untuk dosis arang tempurung kelapa dan sebesar 40 g untuk dosis pupuk kompos bokashi, untuk pertumbuhan diameter penambahan dosis arang tempurung kelapa sebesar 25 g dan dosis kompos bokashi sebesar 0 g, dan untuk biomassa akar dosis campuran untuk arang tempurung kelapa sebesar 50 g dan dosis kompos bokashi sebesar 60 g. Kata kunci: Palaquium spp., tailing, arang, bokashi
Keyword: Palaquium spp, Tailing, Charcoal, Bokashi

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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