Judul: Pertumbuhan Semai Jabon (Anthocephalus cadamba) pada Media Bekas Tambang Pasir dengan Penambahan Sub Soil dan Arang Tempurung Kelapa
Abstrak: The effect of sand mining are environmental degredation and reduction of soil quality (physically, chemistry, or biological). The land of ex-sand mining could be marginal land and causes the revegetation barrier. Soil amendment is a necessary phase for this problem i.e. additional of sub soil and charchoal of coconut shell on the soil. The species selection also determine for revegetation result. Jabon (Anthocephalus cadamba) is an pioneer, adaptive and fast growing species. The aim of this reasearch are to analyze the effect of sub soil and charcoal of coconut shell increment to the growth of jabon seedling on ex-sand mining soil and to find out the optimum dose of sub soil and charcoal of coconut shell increment. The result of this research showed that sub soil and charcoal of coconut shell increment on ex-sand mining soil extend positive influence. The combination 500 g sub soil and 20 g charcoal of coconut shell gave the best growth for jabon seddling on ex-sand mining soil.
Keyword: sub soil, sand mining, coconut shell, charcoal, Anthocephalus cadamba

Judul: Respon Pertumbuhan Semai Jabon (Anthocephalus cadamba Roxb. Miq.) terhadap Pemberian Kompos dan Arang Tempurung Kelapa pada Media Limbah Tambang Pasir
Abstrak: Sand mining activity is having potential to river ecosystem disruption. An amount left over of sands from this activity can cause the river water to become turbid. Sand mining waste utilization as growing medium of Jabon (Anthocephalus cadamba Roxb. Miq.) is necessary to be tested. Jabon is one of basic commodity of timber industries. This research was aimed to analyze growth responses of jabon seedlings with the addition compost and coconut shell on sand mining waste. This research used factorial experiment in complete random design. The result showed that interaction of compost fertilizer and coconut shell charcoal is clearly affected height and total dry weight. Compost with dosage 60 gram and charcoal coconut shell dosage 3% into medium sand mining waste can increase value of the total dry weight of jabon seedling.
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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