Judul: Pengaruh fumigasi terhadap sifat fisis dan mekanis beberapa jenis kayu rakyat
Abstrak: Sampai saat ini sebagian besar kebutuhan kayu masih dipenuhi dari hutan alam. Dengan luas hutan rakyat Indonesia sekitar 1.568.415,63 ha, maka potensi kayunya adalah 39.416.557 m3. Dengan demikian hutan rakyat telah menjadi alternatif solusi untuk pemenuhan defisit kebutuhan kayu di pasar. Namun, kayu rakyat memiliki kualitas yang rendah (warna pucat dan tidak seragam, corak tersebut kurang menarik). Oleh karena itu, diperlukan modifikasi penampilan kayu dengan cepat, mudah, dan murah. Salah satu caranya adalah dengan menggunakan metode fumigasi menggunakan amonia. Penelitian ini bertujuan untuk mengetahui pengaruh fumigasi terhadap sifat fisis dan mekanis beberapa kayu rakyat Contoh uji yang digunakan adalah kayu Nangka, Mahoni, Pasang, dan Rambutan. Sifat fisis yang di analisis adalah kadar air, kerapatan, berat jenis, dan stabilitas dimensi. Sifat mekanis yang dianalisis adalah lentur statik, tekan sejajar serat, dan kekerasan. Fumigasi dilakukan selama 48 jam dengan menggunakan 2 liter amonia. Fumigasi menyebabkan terjadinya perubahan warna yang signifikan pada kayu Nangka, kayu Mahoni, kayu Pasang, dan kayu Rambutan. Perubahan tersebut diduga disebabkan oleh ikatan antara tanin dengan ammonia sehingga terbentuk suatu pigmen baru. Berdasarkan analisis keragaman, perlakuan fumigasi pada kayu tidak memberikan pengaruh yang nyata terhadap sifat fisis dan mekanis yang diujikan kecuali nilai kadar air.
Keyword: Kayu Rakyat, Fumigasi, Sifat Fisis, Fumigation on community forest, Mahoni, Bogor Agricultural University

Judul: Pengaruh Fumigasi Amonia terhadap Sifat Fisis, Mekanis dan Keawetan Tiga Jenis Kayu Hasil Tanaman
Abstrak: Recently, sengon (Falcataria moluccana), karet (Hevea brasiliensis) and mangium (Acacia mangium) woods became popular for many wood industries in Indonesia due to the lack of better quality of wood. Sengon wood is for pallet and/or packaging material, while karet- and mangium woods are for meubel and furniture manufacturing. These three wood species belong to non durable wood: sengon and mangium woods are commonly obtained from the younger trees (four to less than 10 year-old), while karet wood even though it is around 25 year-old, it is attacked easily by blue-stain and other destroying fungus. In order to improve the quality of these three woods, fumigation technique using ammonia was performed. Since effect of ammonia fumigation on physical-mechanical properties and natural durability of wood, especially the wood from plantation, was not study well, therefore, the aim of this study was focussing on the above aspect. It is hope that fumigation process applied has no negative effect on wood quality. The main material used was heartwood portion from the middle part of tree stem of sengon, karet and mangium. All tree species were obtained from rural forest of surrounding areas of IPB Darmaga Campus. There was no information about tree age, but their diameters were around 20-25 cm. The parameters studied consist of wood moisture content (MC), specific gravity (BJ), modulus of elasticity (MOE), modulus of rupture (MOR), maximum compression strength parallel to the grain (σtk//), hardness in radial and tangential surfaces and also the weight loss. All sample size and shape and also the testing procedure were carried out following the ASTM-D143 94 in 2007, with four replications. Data were then analyzed with a random two-factor factorial design using SAS 9.1.3 and Microsoft Excel 2010. The result showed that ammonia fumigation is significantly affects wood MC and weight loss. Wood MC and weight loss were also influenced by wood species, while interaction between wood species and ammonia fumigation was not. After fumigation, wood MC tended to increase (8.40-22.80%), while the weight loss tended to decrease (27.26-56.48%). The highest increasing of MC was found on mangium wood, while the lowest on rubber wood. After fumigation, karet wood was more durable compared to sengon wood. The research also showed that ammonia fumigation and the interaction between wood species and fumigation treatment have no significant effect on SG, MOE, MOR, σtk// and wood hardness. SG and all mechanical properties studied were influenced only by wood species.
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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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