Judul: Color and Wettability of Impregnated Jabon and Ganitri Wood by MFFA with Nano-SiO2
Abstrak: Kayu cepat tumbuh memiliki siklus tebang yang pendek sekitar 6-7 tahun, namun memiliki karakteristik kayu yang inferior, yaitu berat jenis, kekuatan dan keawetan yang rendah. Penelitian ini bertujuan untuk menganalisis pengaruh impregnasi MFFA dan nano-SiO2 terhadap perubahan warna dan nilai keterbasahan pada kayu jabon (Anthocephalus cadamba) dan ganitri (Elaeocarpus sphaericus). Perlakuan terdiri dari 2 faktor yaitu larutan impregnasi dan jenis kayu. Perlakuan larutan impregnasi terdiri dari 3 taraf yaitu kontrol (tanpa perlakuan), MFFA, dan MFFA nano-SiO2 0,5%. Proses impregnasi dilakukan dengan memberikan vakum 0,5 bar selama 60 menit, dilanjutkan dengan memberikan tekanan 2 bar selama 120 menit. Hasil penelitian menunjukkan bahwa perubahan warna (ΔE) yang besar terjadi pada kayu jabon dan ganitri akibat perlakuan MFFA dan MFFA nano-SiO2 0,5% jika dibandingkan dengan kontrol. Penambahan nano-SiO2 pada larutan MFFA dapat meningkatkan kecerahan warna (menurunkan ΔE) pada kedua jenis kayu. Perlakuan MFFA dan MFFA nano-SiO2 0,5% juga memberikan pengaruh yang nyata terhadap nilai sudut kontak dan nilai K. Perlakuan paling optimum untuk keterbasahan kayu jabon dan ganitri diperoleh dengan pemberian perlakuan MFFA nano-SiO2., Fast-growing wood which has a short cutting cycle of about 6-7 years, usually has inferior wood characteristics, namely low density, strength and durability. This study aim was to analyze the effect of MFFA and nano-SiO2 impregnation on discoloration and wettability values of jabon (Anthocephalus cadamba) and ganitri (Elaeocarpus sphaericus) wood. The treatments were the impregnation solution and the wood species. The impregnation solution treatments were consisted of 3 levels, namely control (water treated), MFFA, and MFFA nano-SiO2 0.5%. The impregnation process was initiated by applying a vacuum of 0.5 bar for 60 minutes, followed by applying a pressure of 2 bars for 120 minutes. The results showed that large discoloration (ΔE) occurred in jabon wood and ganitri after being treated by 0.5% MFFA and MFFA nano-SiO2. The addition of nano-SiO2 to the MFFA solution can increase the color brightness (decrease ΔE) in both wood species. The treatment of MFFA and MFFA nano-SiO2 0.5% also had a significant effect on the contact angle and the K values. The optimum treatment for the wettability of jabon and ganitri wood was MFFA nano-SiO2.
Keyword: Discoloration, Impregnation, MFFA, Nano-SiO2, Wettability

Judul: The Improvement of Fast-Growing Wood Species Physical Properties through Impregnation of nano-SiO2
Abstrak: Nano-SiO2 based wood polymer composites are from impregnation of nano-SiO2 and melamine formaldehyde-furfuryl alcohol (MFFA) copolymers. This study aimed at analyzing the impregnation of a mixture of nano-SiO2 and MFFA copolymers on the properties of jabon and ganitri wood and explaining characteristics of jabon and ganitri wood after the process. The result showed that impregnation process could increase the physical parameters of jabon and ganitri wood. The wood density of jabon has risen from 0.32 to 0.56 g /cm3 , and that of ganitri wood has increased from 0.41 to 0.62 g /cm3 . Both weigt percen gaint of jabon and ganitri wood has risen by 68.34%, and 65.73%. The anti swelling efficiency jabon and ganitri has also increased by 46.66% and 70.19%.In addition, the bulking effect of jabon and ganitri wood was risen by 7.55% and 7.74%. The water uptake Jabon was decreased from 219.79% to 75.49%, and ganitri has also reduce from 86.4% to 45.32%. Wood characteristics identification after the impregnation process with nano-SiO2 and MFFA was using FTIR and XRD. The FTIR study showed that the peak of absorption shifted to a higher wave number on wood impregnated with nano-SiO2. The XRD study verified that there was a decrease in the crystallinity of wood cellulose. The presence of MFFA and nano-SiO2 polymers in the wood cell walls and cell lumen was detected using the Scanning Electron Microscopy (SEM). The results of physical properties and characterization tests with FTIR, XRD and SEM showed that jabon and ganitri impregnated with nano-SiO2 0.5% and MFFA are the optimal combinations.
Keyword: impregnation, fast-growing species, MFFA copolymer, nano-SiO2, physical properties

Judul: Query Expansion based on Bilingual Dictionary Using Conditional Probability
Abstrak: Query expansion is a technique that can be used to bridge vocabulary gaps between queries and documents in the collection. With query expansion, user will be helped to formulate queries well so that user will optimize the search result. In this study, the expansion term was resulted from the translation of bilingual dictionary. Subsequently, several terms of expansion were elected based on the closeness of its relationship with the original query. This research showed that conditional probability can be used to select expansion term in bilingual translation method query expansion. The result of 1000 documents was more than 97% relevan document can be retrieved by this system. The more expansion term used, the larger number relevan document was retrieved.
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