Judul: Efektifitas Penambahan Fulvic Acid dan Fosfat pada Pertumbuhan Jabon (Anthocephalus cadamba Roxb Miq.) di Media Bekas Tambang Emas
Abstrak: Pelaksanaan kegiatan reklamasi dan rehabilitasi pada lahan pasca tambang terdapat kendala kondisi lahan yang marginal dan beracun. Kondisi toksisitas yang ditimbulkan pada lahan marginal dapat diatasi dengan pembenahan lahan dan pemilihan jenis yang sesuai. Pemilihan jenis jabon (Anthocephalus cadamba Roxb Miq.) dan penambahan fulvic acid dapat menjadi alternatif solusi. Penelitian ini dilakukan untuk mengetahui efektivitas pemberian fosfat dan fulvic acid pada pertumbuhan tanaman di lahan bekas tambang. Perlakuan pemberian fulvic acid dan pupuk fosfat memberikan pengaruh yang berbeda nyata terhadap pertumbuhan tanaman A. cadamba pada parameter tinggi, jumlah akar sekunder, biomassa, berat basah total, dan nilai indeks mutu bibit. Pertumbuhan tanaman A. cadamba pada media bekas tambang emas dengan pemberian fulvic acid dan pupuk fosfat memberikan respon pertumbuhan tinggi dan biomassa terbaik dengan persen kenaikan terhadap kontrol masing-masing sebesar 63.35% dan 18.5% pada perlakuan F3P1 (fulvic acid 1.25% dan pupuk fosfat 1.5 gram)
Keyword: Anthocephalus cadamba, fulvic acid, pasca tambang, pupuk fosfat

Judul: iRespon Pertumbuhan Tanaman Jabon (Anthocephalus cadamba (Roxb.) Miq.) Terhadap Pengapuran di Areal Bekas Tambang
Abstrak: The main problem of reclamation activities in the postmining land was marginal land that could not support the growth of plants, due to pH and the low level of nutrient. So that, the selection of local species which adaptable and the appropriate silviculture treatment was needed. Jabon (A. cadamba) is one of local tree species that had high prospect, because jabon classified into fast growing species, able to adapted various site conditions, and the silviculture treatment was relatively easy. Dolomit and gypsum were materials that contained of Ca (Calcium), which able being applied to increase the soil pH. This objectives research was to determine the effect of dolomit, crude gypsum and manure fertilizer on the growth of Jabon in postmining land at PT. Tunas Inti Abadi. The fertilizers treatment consisted of three treatments. There were 2 kg of manure fertilizer (N), 2 kg of manure fertilizer + 200 g of dolomit (KN), and 2 kg of manure fertilizer + gipsum 200 g (GN). The parameters that be measured were diameter, height, crown diameter, percentage of living. The combination of dolomit and manure fertilizear had significant effect on the 95% confidence interval the diameter of Jabon.
Keyword: reclamation, calcification, fertilizer, jabon

Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology