Judul: Pengaruh Pemberian Kompos dan Arang Kayu terhadap Pertumbuhan Semai Jabon (Anthocephalus cadamba Roxb. Miq.) pada Media Bekas Tambang Pasir
Abstrak: The sands mining can cause decreasing of sand number, make air pollution, damage the roads, and water quality degradation. The sands mining will produce waste in the form of ex sand mine. The characteristic of sands are low nutrients, less on water retention, and porous. This is an obstacle for revegetation in mining land that not suitable for plant growth. Revegetation activities conducted to know the plant growth in ex sand mine media. The selection of tree species is important to the success of revegetation in ex sand mine media. Jabon (A. cadamba) is fast growing species at a young age and grow in various soil. The method in this research is completely randomized design with two factorial. The first factor is compost and the second factor is wood charcoal. The parameters are height, diameter, and total dry weight. Statistical test showed that compost gave significant effect on jabon seedling height growth at 95% confidence interval. Interaction between compost and wood charcoal gave significant effect on jabon seedling height growth at the 95% confidence interval. Charcoal didn’t give significant effect on height, diameter, and total dry weight.
Keyword: 

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.
Keyword: 

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