Judul: Effect of Strand Pretreatment on Physical and Mechanical Properties of Oriented Strand Board from Sengon Wood (Paraserianthes falcataria (L.) Nielsen)
Abstrak: Penelitian ini bertujuan mengevaluasi karakteristik OSB kayu sengon dengan perlakuan pendahuluan steam dan steam bilas NaOH 1%. Strand kayu sengon diberi perlakuan steam pada suhu 126 ℃ dengan tekanan 0,14 MPa selama 1 jam dan dilanjutkan dengan pembilasan NaOH 1%. Strand dicampur dengan perekat Phenol Formaldehyde (PF) pada konsentrasi 10%. Papan berukuran (30x30x0,9) cm3 disusun 3 lapis dengan kerapatan target 0,55 g.cm-3 dan nisbah lapisan 25:50:25. Pengujian sifat fisis dan mekanis mengacu pada standar JIS A 5908 (2003) yang hasilnya dibandingkan dengan standar CSA 0437.0 (Grade O-1). Hasil penelitian menunjukkan bahwa perlakuan pendahuluan strand memberikan pengaruh terhadap stabilitas dimensi OSB. Perlakuan steam bilas NaOH 1% menghasilkan OSB dengan sifat fisis yang lebih baik dari perlakuan steam tanpa perlakuan lanjutan. Namun, perlakuan steam dan steam bilas NaOH 1% tidak berpengaruh terhadap sifat mekanis OSB. Secara keseluruhan, karakeristik OSB pada setiap perlakuan pendahuluan mampu memenuhi standar CSA 0437.0 (Grade O-1), terkecuali pada beberapa parameter sifat mekanis., The objectives of this research were to evaluated the characteristics of OSB from sengon wood with steam treatment and steam-treated followed by washing 1% NaOH. The sengon wood strand was treated with steam at a temperature of 126 ℃ with a pressure of 0,14 MPa for 1 hour and followed by washing with 1% NaOH. Strands were mixed with phenol formaldehyde (PF) adhesive at a concentration of 10%. Three layered of OSB was made with the size of (30x30x0,9) cm3, target density of 0,55 g.cm-3, and shelling ratio of 25:50:25. Testing of physical and mechanical properties of OSB refers to the JIS A 5908 (2003) standard and the results are compared with the CSA 0437.0 (Grade O-1) standard. The results show that the pretreatment of strand has an effect on the dimensional stability of OSB. The steam-treated follow by washing with 1% NaOH produce OSB with better physical properties than the steam without further treatment. However, the steam and steam-treated follow by washing with 1% NaOH has no effect on the mechanical properties of the OSB. Overall, the characteristics of OSB in each pretreatment met the CSA 0437.0 (Grade O-1) standard, prefix on some parameters of mechanical properties.
Keyword: kayu sengon, perlakuan pendahuluan, PF, OSB, pretreatment, sengon wood

Judul: Effect of Strand Pretreatment on Characteristics of  Oriented Strand Board from Andong Bamboo, Tali Bamboo, and Their Mixtures
Abstrak: Penelitian ini bertujuan mengevaluasi pengaruh perlakuan pendahuluan pada strand terhadap karakteristik Oriented Strand Board (OSB) bambu andong, tali, dan campurannya. Perlakuan pendahuluan steam diterapkan pada strand dengan suhu 126 ̊C selama 1 jam dalam tekanan 0,14 MPa serta dilanjutkan dengan pembilasan NaOH 1%. Strand dicampur dengan perekat fenol formaldehid (PF) pada konsentrasi 8%. Papan berukuran (30x30x0,9) cm3 disusun sebanyak 3 lapis dengan berbagai nisbah campuran. Nisbah lapisan papan yang digunakan adalah 25:50:25 dengan kerapatan target ± 0,7 g.cm-3 . Pengujian sifat fisis dan mekanis OSB mengacu pada standar JIS A 5908 (2003) yang hasilnya dibandingkan dengan standar CSA 0437.0 (Grade O-1). Hasil penelitian menunjukkan bahwa perlakuan steam bilas NaOH 1% pada strand dapat meningkatkan stabilitas dimensi dan kekuatan mekanis (keteguhan rekat) OSB. Peningkatan rasio jenis strand bambu tali berbanding lurus dengan stabilitas dimensi dan keteguhan rekat OSB. Papan dengan nisbah campuran 50:50 menghasilkan karakteristik yang paling optimal. Keseluruhan OSB memenuhi standar CSA 0437.0 (Grade O-1)., The objectives of this research were evaluated the effect of strand pretreatment on the characteristics of Oriented Strand Board (OSB) from andong bamboo, tali bamboo, and their mixtures. Steam treatment was applied to the strand with a temperature of 126 oC for 1 hour under pressure of 0.14 MPa and followed by rinsing of 1% NaOH. Strand were mixed with phenol formaldehyde (PF) adhesive at a concentration of 8%. Three layered of OSB was made with the size of (30x30x0.9) cm3 with various mix ratio of strand types. The shelling ratio of boards is 25:50:25 with target density of ± 0,7 g.cm-3 . The physical and mechanical properties test of OSB refers to the JIS A 5908 (2003) standard and the results are compared with the CSA 0437.0 (Grade O-1) standard. The results show that the steam-treated follow by 1% NaOH rinse on the strand increase the dimensional stability and mechanical strength (internal bond) of OSB. The increase in mix ratio of tali bamboo is directly proportional to the dimensional stability and internal bonding of OSB. Boards with mix ratio of 50:50 produce the most optimal characteristics. All OSBs meet CSA 0437.0 (Grade O-1) standard.
Keyword: bambu andong, bambu tali, campuran, OSB, perlakuan pendahuluan, andong bamboo, mixtures, pretreatment, tali bamboo

Judul: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
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