Judul: Pengujian Laboratoris Efikasi Larutan Kitosan terhadap Rayap Tanah Coptotermes curvignathus Holmgren (Isoptera: Rhinotermitidae)
Abstrak: Subterranean termite Coptotermes curvignathus Holmgren (Isoptera: Rhinotermitidae) has been known as the most important structural pest that causes significant economic losses on building in Indonesia. Up to now termite control techniques that have been applied are wood preservation and soil treatment, both of the techniques could causing environment pollution. Meanwhile chitosan is known as natural polymer that potentially could developed as wood preservative due to its bioactive compound. A laboratory study was conducted to evaluate the efficacy of chitosan in three concentration levels (0.5%, 0.75%, and 1%) against subterranean termite C. curvignathus. Chitosan was dissolved in 1% acetatic acid solution then applied to wood samples made from pine board 10 cm x 8 cm x 2 cm with cold soaking treatment for three days. Wood samples were exposed to subterranean termite C. curvignathus for three weeks based on PSIH-IPB-1998 standard method. Retention of chitosan solution, termite mortality, and degree of protection of wood samples were determined. The results showed that concentration of chitosan solution affect the retention, termite mortality, and degree of protection of wood samples. Wood samples at 1 % concentration were promoted 3.50 kg/m3 retention and caused 98.17% termite mortality with maximum degree of protection of wood samples against C. curvignathus. Chitosan could develop as a wood preservative, especially for protection of wood products that are not directly exposed to weather. However further studies are needed to determine leachibility, mode of action, as well as optimum dose of chitosan solution.
Keyword: wood preservation, Coptotermes curvignathus, Chitosan

Judul: Pengujian Laboratoris Efikasi Hexaflumuron 0.5% terhadap Rayap Tanah Coptotermes curvignathus Holmgren (Isoptera: Rhinotermitidae)
Abstrak: Subterranean termite Coptotermes curvignathus Holmgren (Isoptera: Rhinotermitidae) is the most important buildings destructing insects in Indonesia. Up to now, soil treatment and wood preservation are the most popular termite control techniques in urban areas. However, applications of both techniques could causing environmental pollution. Meanwhile termite baiting is known as more environmentally friendly termite control technique. One of the active ingredient used in the baiting system is hexaflumuron. A laboratory study was conducted to determine the efficacy of two formulations of hexaflumuron 0.5 % i.e blocks formulation and pellet formulation, against subterranean termite C. curvignathus based on PSIH-IPB-1998 standard methods. The results showed that both formulations of hexaflumuron 0.5 % is effective to eliminate the C. curvignathus. However, palatability of pellet formulation (49.43 %) is much higher than palatability of blocks formulation (8.52 %)
Keyword: palatability, subterranean termites, hexaflumuron

Judul: Sifat operasi dan eksistensi invers suatu matriks dalam aljabar max-plus
Abstrak: Karya ilmiah ini membahas sifat-sifat operasi dalam aljabar max-plus dan sifat-sifat yang diaplikasikan pada matriks serta eksistensi invers matriks dalam aljabar max-plus. Operasi-operasi matriks yang dapat diaplikasikan dalam aljabar max-plus meliputi operasi penjumlahan dan perkalian antar matriks, matriks transpose, matriks identitas, matriks segi pangkat ke-k, serta perkalian matriks dengan skalar. Sifat- sifat yang berlaku untuk matriks dalam aljabar max-plus yaitu sifat asosiatif (untuk operasi penjumlahan dan perkalian), komutatif (hanya untuk operasi penjumlahan), dan distributif. Eksistensi invers suatu matriks a ∈ dalam aljabar max-plus dapat dipastikan ada jika dan hanya jika a merupakan perkalian matriks permutasi dan matriks diagonal . Max nxn p ( ) i d 
Keyword: matriks, aljabar max-plus