Judul: Pengaruh Metode Pengawetan Berbahan Aktif Boron pada Kayu Jabon terhadap Rayap Tanah dan Jamur Pelapuk Kayu
Abstrak: Anthocephalus cadamba known as jabon in Indonesia is one of fast growing species. However, it has poor durability and classified into IV-V of durability class. It is necessary to apply wood preservation in terms of Improving the timber durability. The aim of this research is to examine the effectiveness of several methods in preserving wood using particular chemical preservatives from active boron against subterranean termites (Coptotermes curvignathus) and wood decay fungi (Schizophyllum commune). The preservatives consist of 5% concentrations of mixed Borax-Sodium Carbonax (BC) and Boric Acid Equivalent (BAE), cold bath, hot–cold bath and vacuum press were applied as the preservation methods. There were two responses observed in this research: the mortality of Subterranean Termites, and the timber weight loss resulting from the termites and the wood decay fungi attacks as well. The results show that the preservation of jabon timber using BC and BAE can improve its durability from C. curvignathus and S. commune attack. The durability from C. curvignathus attack increases from class V to class I while the durability from S. commune attack also improves from class V to class II.
Keyword: Sodium Carbonate., Schizophyllum commune, Coptotermes curvignathus, boron, Anthocephalus cadamba

Judul: Pengaruh Metode Pengawetan Berbahan Aktif Boron pada Kayu Jabon (Anthocephalus cadamba Miq.) terhadap Serangan Rayap Kayu Kering dan Jamur Pelapuk Kayu
Abstrak: Jabon woods is one of the small scale community forest that had low durability and classified at IV-V of durability class, it is necessary for the preservation of the wood to increase the durability of timber value. The aim of this research is to know the effectiveness of some methods of preserving wood and preservative from active boron against dry wood termites and wood rot fungi.This research was using 5% concentrations of Borax mixed with Sodium Carbonate (BC) and Boric Acid Equivalent (BAE) as preservatives and using vacuum press, hot–cold bath, and cold bath as method of preserving. The observed object of this research are mortality of dry wood termites value, and weight loss of timber resulting from dry wood termites Cryptotermes cynocephalus and wood white rot fungi attack. The result showed in this research is the value of dry wood termite mortality and weight-timber values resulting from the attack dry wood termites C. cynocephalus and wood white rot fungi Pycnoporus sp. The results showed that the preservation of wood with preservatives Jabon BC and BAE can improve the durability of the dry wood termite attack C. cynocephalus of class IV to durability class I and II, while the wood rot fungi Pycnoporus sp. attack increased from durability class V be durability class II-III.
Keyword: Pycnoporus sp., Natrium Carbonate, Cryptotermes cynocephalus, boron, Anthocephalus cadamba

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
Keyword: