Judul: Color Changes and Resistance of Pinewood and Sengon Impregnated with Furfuryl Alcohol against Subterranean Termites through Graveyard Test
Abstrak: Penelitian ini bertujuan menganalisis perubahan warna yang terjadi serta pengaruh perlakuan impregnasi furfuril alkohol terhadap ketahanan kayu pinus dan kayu sengon dari serangan rayap setelah uji kubur selama 1 tahun. Kayu pinus dan kayu sengon yang telah diimpregnasi dengan furfuril alkohol memiliki penambahan berat berturut-turut sebesar 31,2% dan 79,1%, kerapatan 0,93 g/cm3 dan 0,43 g/cm3, serta kadar air 3,27% dan 2,88%. Setelah dilakukan pengujian kubur, kayu pinus dan kayu sengon mengalami perubahan warna yaitu peningkatan tingkat kecerahan dan memiliki tingkat kehilangan berat secara berturut-turut 4,07% dan 2,09% dengan rata-rata nilai ketahanan untuk kedua jenis tersebut sebesar 9,8. Kayu pinus dan kayu sengon tanpa perlakuan secara berturut-turut memiliki kehilangan berat sebesar 59,02% dan 35,58% dengan rata-rata tingkat ketahanan 4 dan 3,8. Tingkat ketahanan yang tinggi untuk kedua jenis kayu menunjukkan bahwa furfurilasi alkohol dapat meningkatkan ketahanan kayu terhadap serangan rayap tanah., This study aims to analyze the effect of furfuryl alcohol impregnation on color changes and the resistance against subterranean termites of pinewood and sengon after in-ground test for 1 year. Furfurylated pinewood and sengon reach weight percent gain 31.2% and 79.1%, densities 0.93 g/cm3 and 0.43 g/cm3, moisture content 3.27% and 79.1%, respectively. In-ground test caused an increase of lightness on both furfurylated pinewood and sengon. Pinewood and sengon have lost weight 4.07% and 2.09% respectively, with the average resistance level 9.8 on both woods. High resistance score on both woods shows that furfuryl alcohol will increase wood durability against termites.
Keyword: pinewood, sengon, wood resistance, furfuryl alcohol

Judul: Color Changes and Resistance of Mangium and Jabon Impregnated with Furfuryl Alcohol against Subterranean Termites through Graveyard Test
Abstrak: Penelitian ini bertujuan untuk menganalisis dan membandingkan perubahan warna dan ketahanan kayu mangium dan jabon terimpregnasi furfuril alkohol terhadap serangan rayap tanah melalui uji kubur selama 1 tahun. Kerapatan ratarata pada kayu mangium dan jabon terimpregnasi furfuril alkohol masing-masing sebesar 0,76 g/cm3 dan 0,81 g/cm3. Kadar air rata-rata pada kayu mangium dan jabon terimpregnasi furfuril alkohol masing-masing sebesar 3,80% dan 2,23%. Nilai rata-rata WPG pada kayu mangium dan jabon masing-masing sebesar 12,9% dan 169,6%. Pengujian kubur menyebabkan perubahan warna yang termasuk dalam kategori perubahan warna besar pada kedua jenis kayu terfurufurilasi dan pada kayu mangium kontrol. Kedua jenis kayu terfurfurilasi mengalami peningkatan kecerahan setelah uji kubur selama 1 tahun. Nilai rata-rata weight loss kayu mangium dan jabon terimpregnasi furfuril alkohol masing-masing sebesar 18,16% dan 1,18. Nilai tingkat ketahanan kayu mangium dan jabon terimpregnasi furfuril alkohol masing-masing sebesar 8,8 dan 9,4, sedangkan pada kayu kontrolnya masing-masing sebesar 5 dan 0., This study aims to analyze and compare the color changes and resistance of mangium and jabon wood impregnated with furfuryl alcohol against subterranean termite attack through the graveyard test for 1 year. The average density of mangium and Jabon wood impregnated with furfuryl alcohol was 0.76 g / cm3 and 0.81 g / cm3, respectively. The average water content of mangium and Jabon wood impregnated with furfuryl alcohol were 3.80% and 2.23%, respectively. The average WPG values for mangium and jabon were 12.9% and 169.6%, respectively. The graveyard test resulted in a color change that falls under the category of major color change in both the furfurylated wood and in the untreated mangium. The two types of fertilized wood experienced an increase in brightness after 1 year of graveyard test. The average values of weight loss mangium and Jabon wood impregnated with furfuryl alcohol were 18.16% and 1.18, respectively. The resistance level values of mangium and jabon impregnated with furfuryl alcohol were 8.8 and 9.4, respectively, while those for control wood were 5 and 0.
Keyword: furfuryl alcohol, impregnation, jabon wood, mangium wood, wood resistance

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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