Judul: Basic- and processing properties of maniani (Flindersia pimenteliana F. v. Muell) wood from wondama bay, West Papua
Abstrak: Basic- and processing properties of Flindersia pimenteliana F. v. Muell woods from natural forest in Wondama Bay, West Papua were studied comprehensively in order to analyze its proper utilization. The study was carried out by following standards of Deutsche Institute Fuer Normung (DIN), Bristish (BS), Technical Association of Pulp and Paper Industry (TAPPI), Indonesia (SNI) and American Society for Testing and Materials (ASTM). The results showed that maniani wood has decorative figure, white sapwood to pinkish and reddish brown heartwood, fine texture, straight grain, lustrous, good smell, moderately soft and light. Its fiber was classified in to class II. Green moisture content was 57.00% and specific gravity was 0.61, while tangential and radial shrinkages were 2.48% and 1.21%, respectively. MOE was 108839.40 kg cm-2, while MOR, compressive strength parallel to grain, hardness, shear strength, tension- and cleavage strengths were 817.43 kg cm-2, 426.33 kg cm-2, 435.75 kg cm-2, 135.71 kg cm-2, 111.60 kg cm-2 dan 16.96 kg cm-2, respectively. The extractives content in cold water, hot water, NaOH 1% and ethanol benzene were 4.82%, 7.17%, 16.42%, and 4.30%, respectively. The contents of holo-cellulose, α-selulosa, lignin, ash and silica were 82.91%, 45.54%, 24.74%, 0.50% and 0.15%, respectively. Natural resistances to subterranean termite, dry-wood termite and decay fungi were classified into V (poorly resistant), I (very resistant) and II (moderately resistant), respectively. Preservative application treatment using cold soaking method showed that its retention was 0.97 kg m-3, while penetrations of copper and boron were 0.72 mm dan 3.69 mm, respectively. The wood was good in drying quality with temperature of 50 ºC – 80 ºC and RH 80% – 30%. Properties of planning, turning and boring were good, while moulding and sanding properties were very good. Finishing properties were generally good except for resistance to soap solution and sauce. Based on these properties studied, it could be recommended that maniani wood is suitable for wood craft, furniture, mouldings and interior construction purposes.
Keyword: Flindersia pimenteliana F.v. Muell, wood properties, wood processing properties, wood utilization

Judul: The Physical and Mechanical Properties of Modified Manii Wood (Maesopsis eminii Engl.) with Boric Acid, Sodium Silicate and Heat Treatment
Abstrak: Kayu manii (Maesopsis eminii Engl.) merupakan kayu cepat tumbuh, tetapi keawetannya rendah (III – IV), maka diperlukan pengawetan. Pengawet asam borat bersifat insektisida maupun fungisida, namun mudah tercuci air. Natrium silikat dan pemanasan diharapkan dapat mengurangi ketercucian. Penelitian ini bertujuan untuk mengevaluasi sifat fisis dan mekanis kayu manii termodifikasi asam borat, natrium silikat dan pemanasan. Kayu manii diimpregnasi dengan asam borat dan natrium silikat dengan tekanan 7 kgf cm-2 selama 4 jam dan pemanasan dengan suhu 70 °C, 140 °C selama 4 jam serta steam 120 °C selama 1,5 jam. Pengujian mencakup kerapatan, berat jenis, daya serap air, ketercucian, anti-swelling efficiency, penyusutan, MOE, MOR dan kekerasan. Perlakuan pasca pengawetan asam borat dengan natrium silikat dan pemanasan 140 °C tidak dapat memperbaiki ketercucian, daya serap air, stabilitas dimensi, MOE dan MOR kayu manii, namun meningkatkan kerapatan, berat jenis dan kekerasannya., Manii wood (Maesopsis eminii Engl.) is fast growing species, but has low durability (III – IV) and requires preservation. Boric acid has insecticidal and fungicidal properties, but is easily washed off by water. Sodium silicate and heating are expected to reduce leaching. This study aims to evaluate the physical and mechanical properties of manii wood modified boric acid, sodium silicate and heating. Manii wood was impregnated with boric acid and sodium silicate at a pressure of 7 kgf cm-2 for 4 hours and heating process with a temperature of 70 °C, 140 °C for 4 hours and steam 120 °C for 1,5 hours. The tests included density, specific gravity, water absorption, leaching, anti-swelling efficiency, shrinkage, MOE, MOR and hardness. Post-treatment following boric acid preservation with sodium silicate and heating at 140 °C did not improve the leaching, water absorption, dimensional stability, MOE and MOR of manii wood, but increased its density, specific gravity and hardness.
Keyword: boric acid, heating, physical-mechanical properties, sodium silicate

Judul: Dynamical System of Hepatitis B in Three Groups with Vaccination
Abstrak: The aim of this study is to modify the hepatitis B transmission model in three age groups involving vaccination from the model conducted by Zhoe and Zhang.The method used is to analyze the stability of the fixed point and its basic reproduction number (R_0). Performed stability analysis and numerical simulation to see population dynamics. Next, a sensitivity analysis of the parameters was carried out to see its effect on R_0. From the analysis obtained two fixed points, namely non-endemic and endemic fixed points. Non-endemic fixed points are locally asymptotically stable if R_0 <1 Meanwhile, the endemic fixed point is locally asymptotically stable if R_0 > 1. Hepatitis vaccination affects the number of susceptible population, because the more successful the vaccination, the smaller the number of susceptible populations so that the smaller the population will be infected.
Keyword: Dynamic, Hepatitis B, Vaccine, Mathematical model