Judul: Respon Pertumbuhan Jabon terhadap Sumber Benih dan Dosis Pupuk yang Berbeda pada Lahan Bekas Tambang Batubara di PT Kaltim Prima Coal, Sangatta, Kalimantan Timur
Abstrak: The activities of mining exploitation included scraped activity of top soil, dredging and hoarding could result negative impact for environment. The impact of mining activity could open forest canopy layer, soil erosion, sedimentation, decreasing fertility and stability land, destroy habitats for wildlife, and water environment pollution and significant change of micro climate due to loss of forest function. In every area of ex-mining land is neccesary to do the activities of land reclamation. Jabon is one type of local seeds which could be made as pioner trees in ex-mining land. Jabon is a fast growing species of Rubiaceae family that has many uses.The research is aimed to measure the influence of fertilizing and seed source on the growth of jabon in ex-mining land and obtain optimal dose of fertilizer that is appropriate for growth of jabon. Based on the research, the best fertilizing treatment is fertilizing using 50 g NPK anorganic. Seed from Malang is more superior compared with Sangatta source of seeds.
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Judul: Pertumbuhan Semai Jabon (Anthocephalus cadamba Roxb Miq) Pada Media Pasca Penambangan Batubara Yang Diperkaya Fungi Mikoriza Arbuskula, Limbah Batubara dan Pupuk NPK
Abstrak: One of the problems created by coal mining activities is the progressive increase of critical land area size and environmental damage, which are among other things in the form of worsening physical, chemical and biological properties of soils which lead to decrease of soil fertility and disturbed plant growth. Growth and nutrient absorption by Jabon seedlings have been studied in terms of their respond toward application of Arbuscular Mycorrhizal Fungi (AMF), coal waste, and soil media being used after coal mining operation. The experiment was designed as factorial completely randomized design, comprising 3 treatment factors, namely, species of AMF inoculants (control, Glomus sp., and Gigaspora sp.), growth media (control, mixture of 15% south Kalimantan coal, and mixture of 15 % Jambi coal) and concentration of NPK fertilizer (control, 2 gram/polybag, and 4 gram/polybag) with 10 replications, so that in total, there were 270 experimental units. Results showed that interaction between AMF, growth media and fertilizer had significant effects on parameters of diameter increment, shoot biomass, root biomass, total dry weight, index of planting stock quality, and percent of AMF colonization. Parameter of height increment and number of Jabon seedling leaves were affected by interaction between AMF and fertilizer. Treatment combination of AMF inoculants, coal powder, and NPK fertilizer was able to increase the concentration and absorption of nutrients N, P and K. The three treatments combination showed positive correlation between increase in concentration of nutrients N, P and K; and shoot biomass of Jabon seedlings.
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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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