Judul: Kualitas Biopelet dari Limbah Kayu Mahoni dan Sengon
Abstrak: Limbah dari industri kayu dapat dimanfaatkan sebagai bahan baku biopelet yang ramah lingkungan. Biopelet adalah bahan bakar biomassa berbentuk pelet yang memiliki keseragaman ukuran, bentuk, kelembaban, kerapatan, serta mempunyai kandungan energi yang tinggi. Penelitian ini menggunakan bahan baku limbah industri kayu berupa serbuk kayu mahoni dan sengon. Biopelet dibuat dengan diameter 6 mm, 8 mm, dan 10 mm. Pengujian yang dilakukan meliputi kerapatan, keteguhan tekan, kadar air, kadar abu, kadar zat terbang, kadar karbon terikat, dan nilai kalor yang mengacu pada standar SNI 8021-2014. Hasil penelitian menunjukkan bahwa biopelet yang dihasilkan mempunyai nilai kerapatan 0.80-0.95 g/cm3, keteguhan tekan 123.50-503.61 kg/cm2, kadar air 8.66-9.59%, kadar zat terbang 64.55-66.43%, kadar abu 2.57-4.76%, kadar karbon terikat 21.34-22.52%, dan nilai kalor 4052-4292 kkal/kg. Nilai pengujian biopelet ini sudah memenuhi standar SNI 8021-2014, kecuali nilai kadar abu tidak memenuhi standar. Kualias biopelet terbaik terbuat dari jenis kayu mahoni dengan ukuran diameter 6 mm.
Keyword: biopellet, diameter, Falcataria moluccana, Swietenia macrophylla

Judul: Pemanfaatan Limbah Kelapa Sawit (Elaeis guineensis Jacq.) dan Serbuk Kayu Mahoni sebagai Bahan Baku Biopelet
Abstrak: Despite widely known for its use as food, palm’s wastes produced by the plantation aren’t optimally used yet. Palm waste has potential to be made into fuel, one of which is biopellet. This research aims to find out the biopellet’s characteristic made from palm waste and examine the effect of augmenting mahoni sawdust toward biopellet’s quality. Materials used are exterior part of palm plant’s trunks, interior part of palm’s trunks, palm’s midrib, leaves, and mixed materials such as mahoni sawdust (0%, 15%, 30%, 50%). Biopellet was made using 40-60 mesh particle and compressed in 200 oC temperature for 15 minutes. Biopellet characteristics were examined using SNI 06-4369-1996 and SNI 01-2891-1992 standard. Research results show that biopellet’s water content is 0.14% - 2.34%, with volatile matter 62.34% - 76.29%, 1.12% - 13.32% ash content, 0.65 g/cm3 – 0.94 g/cm3 density, calor value as much as 4269.27 cal/g – 4729.99 cal/g, sulphur content 0.012% - 0.038%, nitrogen 0.290% - 1.95%, and chlorine content < 0.01%.
Keyword: calor value, biopellet, sawdust, oil palm

Judul: Implementation of Spatio-Temporal Change Query in Relational Database.
Abstrak: Geographic object changes in various views. Object changes are recorded using a model of static storage. No historical connection between old version data and new version data has been built. For that, a storage model of spatio-temporal queries that can analyze spatio-temporal changes has been developed. The object changes the geometry are grouped according to the taxonomy of Spatio-Temporal Pattern Change. This research has been able to apply the query patterns change including born, expand, merge, contract, split, normal and die. This query based on geometric (area) changes. The implementation of spatio-temporal change queries represents an object changes continuously with easy, change detection is done by comparing two versions of data. Keyword: spatio-temporal change query, spatio-temporal change pattern.
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