Judul: Sifat Fisis, Anatomi dan Sifat Pengeringan Tiga Jenis Kayu Kurang Dikenal dari Kupang dan Papua
Abstrak: Saat ini, kebutuhan kayu di Indonesia semakin meningkat dan tidak dapat dipenuhi oleh pasokan kayu komersial dari hutan alam sehingga perlu menggunakan jenis kayu non-komersial yang kurang dikenal. Untuk memanfaatkan jenis kayu yang kurang dikenal, membutuhkan pemahaman yang baik pada sifat kayu sehingga dapat menghasilkan produk kayu berkualitas. Tujuan dari penelitian ini adalah untuk memaparkan sifat fisis, anatomi dan sifat pengeringan dari beberapa jenis kayu kurang dikenal, seperti kwari (Tetrameles nudiflora), kabesak (Acacia leucophloea) dan timo (Timonius sericeus). Uji sifat fisis meliputi kadar air, berat jenis, dan penyusutan kayu. Struktur anatomi kayu diamati setelah mengiris contoh uji kayu dengan mikrotom pada penampang tangensial, radial dan longitudinal menurut metode IAWA (2008). Uji sifat pengeringan kayu dilakukan dengan mengeringkan contoh uji pada suhu 100 oC sampai berat konstan. Evaluasi cacat permukaan dilakukan pada akhir pengujian berdasarkan metode Terazawa setiap 2 jam. Kayu dengan kerapatan tinggi (kabesak dan timo) relatif lambat dalam pengeringan dan mudah terjadi cacat daripada kayu kwari. Kayu kwari memiliki berat jenis rendah, pori-pori besar dan frekuensi yang tinggi. Pengeringan kayu kabesak dapat disarankan dengan jadwal pengeringan 45-80 oC dan 90-28%, jadwal pengeringan kayu timo adalah suhu 50-80 oC dan kelembaban 85-30%, sedangkan kayu kwari adalah 60-85 oC dan 82-27%.
Keyword: Sifat pengeringan, jadwal pemgeringan, kwari, kabesak dan timo

Judul: Sifat Dasar dan Sifat Pengeringan Tiga Jenis Kayu Kurang Dikenal Asal Hutan Alam Papua
Abstrak: One of serious problems which is commonly complained in wood industries is wood drying process because of long time and frequent deformation and checks. So, wood drying is an imperative process in wood industries. Indonesia has about 4 000 wood species, but only a few of these woods are well known in their properties and uses. Wood drying property is influenced by physical and anatomy properties of different woods. The objective of this research was to reveal the physical properties, anatomy and drying properties of three lesser known wood species from natural forests in Papua, namely briya hatam (Rhustaitensis guild) pala hutan (Gymnacranthera paniculata), and ketapang (Terminalia complanata) with respective families comprising Myristicaceae, Anacardiaceae and Combretaceae. These basic properties and drying property were beneficial direction on determining their uses. The physical properties of woods included moisture content, specific gravity and shrinkage. The anatomy of wood was observed based on their structures while wood drying test included drying rate, defects evaluation, and drying schedule. The results of research showed that specific gravity and the anatomy of wood structure influenced the wood drying property. All the three wood species were difficult to be dried. Briya hatam with the higher specific gravity (0.52) had more drying defects than pala hutan and ketapang whose specific gravity 0.47 and 0.38 respectively. According to the drying test and basic properties of woods, the proper drying schedule (temperature and humidity) for briya hitam, pala hutan and ketapang were 4580 0C and 9028%; 5080 0C and 8530%; 5080 0C and 90 – 28% respectively.
Keyword: lesser known species, wood anatomy, wood drying properties, physical properties, wood

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