Judul: Areca Palm Particle Board Using Polyurethane Resin Adhesive
Abstrak: Papan partikel dapat dibuat menggunakan bahan baku berupa limbah kayu, kayu dengan kualitas rendah, dan bahan berlignoselulosa lainnya. Papan partikel secara umum diproduksi menggunakan bahan baku kayu dengan perekat urea-formaldehida. Pelepah pinang bisa menjadi alternatif pengganti kayu sebagai bahan baku papan partakel. Poliuretan adalah perekat yang tidak menyebabkan emisi formaldehida sehingga bisa menjadi alternatif perekat yang ramah lingkungan. Penelitian ini bertujuan menganalisis pengaruh ukuran partikel dan kerapatan pada sifat fisis, sifat mekanis, dan absorpsi suara papan partikel pelepah pinang. Papan partikel ini dibuat dengan menggunakan ukuran partikel (>14 mesh, 14-20 mesh, dan 20-40 mesh) dan kerapatan (0,3 g/cm3, 0,4 g/cm3, dan 0,5 g/cm3). Papan partikel dibuat dengan 20% kadar perekat poliuretan dan ukuran 35 x 35 x 2 cm. Pengujian sifat fisis dan sifat mekanis mengacu pada Standar Nasional Indonesia (SNI) 03-2105-2006. Absorpsi suara mengacu pada standar ISO 11654-1997. Hasil penelitian sifat fisis papan partikel pelepah pinang yaitu kadar air berkisar 8,16-9,68%, kerapatan 0,28-0,52 g/cm3, daya serap air berkisar 156,92-274,33%, dan pengembangan tebal berkisar 12-26,3%. Sifat mekanis papan partikel pelepah pinang yaitu MOE berkisar 0,21-6,90 N/mm2, MOR berkisar 0,21 N/mm2, dan IB berkisar 0,03-0,22 N/mm2. Contoh uji papan partikel pelepah pinang paling optimum untuk absorpsi suara di setiap ukuran partikel berada di kerapatan 0,3 g/cm3 berada pada kelas B berdasarkan klasifikasi absorpsi suara ISO 11654 (1997). Semakin kecil ukuran partikel maka penyerapan suara akan semakin bagus., Raw materials such as wood waste, low-quality wood, and other lignocellulosic materials can be used to make particle board. Particle board is generally produced using wood as raw material with urea-formaldehyde adhesive. Areca nut bark can be an alternative to wood as a raw material for particle board. Polyurethane is an adhesive that does not emit formaldehyde, so it can be an alternative to environmentally friendly adhesive. This study aims to analyze the effect of particle size and density on the physical properties, mechanical properties, and sound absorption of areca nut particle board. This particleboard was made using particle size (>14 mesh, 14-20 mesh, and 20-40 mesh) and density (0,3 g/cm3; 0,4 g/cm3; and 0,5 g/cm3). The particle board is made with 20% polyurethane adhesive content and measures 35 x 35 x 2 cm. Tests for physical properties and mechanical properties refer to the Indonesian National Standard (SNI) 03-2105-2006. Sound absorption refers to the ISO 11654-1997 standard. Particleboards made from areca nut fronds have a water content of 8,16% to 9,68%, density of 0,28 g/cm3 to 0,52 g/cm3, water absorption of 156,92% to 274,33%, and thickness swelling of 12% to 26,3%. Mechanical properties include MOE ranging from 0,21 N/mm2 to 6,90 N/mm2, MOR at 0,21 N/mm2, and IB from 0,03 N/mm2 to 0,22 N/mm2. The most optimal areca nut frond particle board test example for sound absorption in each particle size is at a density of 0,3 g/cm3 and is in class B based on the sound absorption classification ISO 11654 (1997). The smaller the particle size, the better the sound absorption.
Keyword: sound absorption, density, interaction, particle size

Judul: Characteristics of Areca Palm Particle Board with Poly-Urea-Formaldehyde Adhesive at Different Adhesive Levels
Abstrak: Papan partikel secara umum diproduksi menggunakan bahan baku kayu dengan perekat urea-formaldehida beremisi tinggi pada suhu dan tekanan tertentu. Partikel pelepah pinang (non-kayu) menjadi salah satu alternatif pengganti kayu sebagai bahan baku papan patikel. Penelitian ini bertujuan untuk menganalisis pengaruh kadar perekat poli-urea-formaldehida pada sifat fisis, mekanis, dan emisi formaldehida papan partikel pelepah pinang. Serta menganalisis kadar perekat poli- urea-formaldehida yang optimum. Papan partikel dibuat dengan menggunakan kadar perekat berbeda (6%, 8%, 10%, 12%, dan 14%). Papan partikel dibuat dengan kerapatan target 0,8 g/cm3 dan ukuran 25 x 25 x 1,2 cm. Evaluasi sifat fisis, sifat mekanis, dan emisi formaldehida papan partikel mengacu pada Standar Nasional Indonesia (SNI) 03-2105-2006. Analisis statistik menunjukkan bahwa kadar Perekat poli-urea-formaldehida memberikan pengaruh nyata terhadap pengembangan tebal, daya serap air, internal bonding, MOR, MOE, dan emisi formaldehida. Sedangkan pada kadar air dan kerapatan, kadar perekat tidak berpengaruh nyata. Papan partikel yang dihasilkan menggunakan kadar perekat poli-urea-formaldehida 14 % menghasilkan kadar air, internal bonding, dan emisi formaldehida sudah memenuhi standar SNI 03-2105-2006 tipe 8., Particle board is generally produced using wood as raw material with a high emission urea-formaldehyde adhesive at a certain temperature and pressure. Areca bark particle (non-wood) is an alternative to wood as raw material for particle boards. This study aims to analyze the effect of poly-urea-formaldehyde adhesive content on the physical, mechanical, and formaldehyde emission properties of areca nut fiber boards. As well as analyzing the optimum level of poly-urea-formaldehyde adhesive. Particle board was made using different levels of adhesives (6%, 8%, 10%, 12%, and 14%). Particle board was made with a target density of 0,8 g/cm3 and a size of 25 x 25 x 1.2 cm. Evaluation of the physical properties, mechanical properties, and formaldehyde emission of particle board conforms to the Indonesian National Standard (SNI) 03-2105-2006. Statistical analysis showed that the level of poly-urea-formaldehyde adhesive had a significant effect on thickness expansion, water absorption, internal bonding, MOR, MOE, and formaldehyde emission. Meanwhile, the adhesive content had no significant effect on water content and density. Particle board produced using poly-urea-formaldehyde adhesive content of 14% produces water content, internal bonding, and formaldehyde emissions that comply with SNI 03-2105-2006 type 8 standards.
Keyword: physical properties, mechanical properties, formaldehyde emission

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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