Judul: Karakteristik Anatomi dan Sifat Fisis Kayu Terap (Artocarpus sp.) dan Kayu Nyatoh (Palaquium spp.) Asal Kalimantan Utara
Abstrak: Penelitian ini bertujuan untuk menilai kecocokan kayu terap (Artocarpus sp.) dan kayu nyatoh (Palaquium spp.) asal hutan alam di Provinsi Kalimantan Utara sebagai bahan baku industri perkayuan melalui kajian struktur anatomi dan sifat fisisnya. Struktur makroskopis diamati secara langsung dengan lup 15X, sedangkan struktur mikroskopisnya dengan mikroskop cahaya. Dimensi serat diukur melalui sediaan maserasi, sedangkan sifat fisis diukur dengan prosedur standar yang dimodifikasi. Hasil penelitian menunjukkan bahwa kedua jenis kayu yang diteliti berserat lurus hingga berpadu; porositas tata baur dalam pola radial, bidang perforasinya sederhana, noktah antar pembuluh selang-seling, dan berisi tilosis; jari-jari multiseriat 1-3 seri, dan heteroseluler. Pori-pori kayu nyatoh dominan bergabung 2-6 sel, sedangkan pada terap dominan soliter meski ada yang bergabung 2-3 sel serta berisi endapan berwarna. Parenkim aksial kayu nyatoh berbentuk pita tangensial panjang dalam jarak yang teratur, sedangkan pada terap berupa aliform hingga aliform bersambung. Dengan BJ 0.44 (terap) dan 0.33 (nyatoh), serta dengan mutu serat yang masuk kedalam Kelas II, maka kedua jenis kayu yang diteliti dapat digunakan sebagai bahan baku panel kayu dan konstruksi ringan, serta pulp dan kertas. Kayu nyatoh juga dapat digunakan sebagai bahan baku industri mebel.
Keyword: Artocarpus sp., hutan alam, Palaquium spp., sifat fisis, struktur anatomi

Judul: Kajian Struktur Anatomi dan Sifat Fisis Kayu Terap (Artocarpus odoratissimus), A Lesser Known Species Asal Kalimantan Selatan
Abstrak: Wood properties are correlated to proper utilization as well as processing. The objective of this research was to assess anatomical characteristics and physical properties of terap wood from South Kalimantan to promote its better utilization. Wood disk of 5 cm thick from a single tree at 1.3 m from the ground was utilized as sample unit. Radial variation of fiber length, microfibril angle (MFA), wood density, specific gravity (SG) and moisture content was measured from pith towards the bark represented by heartwood portion, sap- and heartwood region as well as sap wood region. Fiber dimension was measured through maceration specimens, while the MFA by microtome specimens. Wood density, SG and moisture content were measured by using gravimetric method. It was showed that wood properties were not affected by sample location within the wood disk. Wood density and SG tended to increase from pith towards the bark, while MFA tended to decrease. Average values of moisture content, wood density, SG, fiber length and MFA are 14.34%, 0.35g/cm3, 0.31, 1198.30±201.54 μm, 20.16±2.74o, respectively. With the 2-nd rank for fiber quality and 4-th rank for the strength, it determined wood could be used as raw materials for pulp and paper production and for lightweight construction.
Keyword: terap wood, microfibril angle, physical properties, anatomical structure

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