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: Karakteristik Hasil Fumigasi Amonia dan Daya Tahan Lapisan Finishing Berpelarut Air Pada Beberapa Jenis Kayu dari Hutan Rakyat
Abstrak: Wood from community forest in general have a pale color, not durable, and has a less attractive appearance. Wood finishing was one of the ways to solve these problem. Ammonia fumigation was one method to change the natural wood’s color. Before marketed, furniture usually coated in order to make the better appearance and reduce the surface erosion. Waterbased wood finish used in this study did not containe toxic and ecofriendly. The purpose of study is to determine color change and durability of wood from community forest after the fumigation of dry wood termites (Cryptotermes cynocephallus Light), determine the cross cut of finishing waterbased, and to determine the durability of finishing waterbased layer for chemical household, hot, and cold. Result of this study showed that jackfriut wood, mahogany wood, teak wood, manilkara wood, and vi rasamala wood occur significant color changes while angsana wood, manii wood, and kaboril wood didn’t occur significant color change. Ammonia fumigation can increase the resistance of wood to dry wood termite attack, where the weight loss of ammonia fumigated wood was smaller than weight loss sample of unfumigated wood. Waterbased wood finished have good resistance to chemical household at one hour and 24 hours intervals and have good resistance to heat and cold. Cross cut result showed that waterbased wood finished have good adhesion at wood surface.
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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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