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: 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.
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Judul: igenvalues and Eigenvectors of Tridiagonal Matrix with Non Constant and Recurrent Diagonal Entries.
Abstrak: Matriks tridiagonal adalah suatu matriks yang mempunyai entri-entri bernilai nol kecuali pada diagonal utama, di bawah diagonal utama (subdiagonal) dan di atas diagonal utama (superdiagonal). Entri pada diagonal utama tidak konstan dan berulang. Setiap entri pada matriks tridiagonal ini adalah bilangan kompleks. Dalam karya ilmiah ini, akan dibuktikan 3 teorema untuk menentukan nilai eigen dengan 2 kasus dan 1 teorema untuk menentukan vektor eigen. Teorema pertama menentukan polinomial karakteristik dari matriks tridiagonal. Polinomial karakteristik dari matriks tridiagonal tersebut digunakan untuk menentukan nilai eigen pada teorema kedua dan ketiga serta menentukan vektor eigen pada teorema keempat
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