Judul: Physical and Mechanical Properties of Kuto Wood (Sterculia macrophylla Vent.) from East Halmahera, North Maluku and Its Potential Use
Abstrak: Kayu Kuto (Sterculia macrophylla Vent.) merupakan salah satu kayu khas Maluku Utara yang memiliki karakteristik pohon yang tumbuh lurus dan berkelompok serta tersebar dari pinggiran pantai sampai pada ketinggian 0 ̶ 900 mdpl.Sifat fisis dan mekanis jenis kayu Kuto ini belum ada laporan ilmiahnya khususnya di Halmahera Timur. Tujuan penelitian ini adalah untuk mengkaji sifat fisis dan mekanis kayu Kuto pada masing-masing bagian (pangkal, tengah, dan ujung), agar mudah untuk diketahui karakteristiknya dan dapat digunakan dengan baik. Pada penelitian ini, pengujian sifat mekanis dilakukan menggunakan mesin ujiUniversal Testing Machine (UTM) Instron type 3369 dan sifat fisis yang diuji yaitu kadar air, berat jenis, dan kerapatan. Hasil penelitian menunjukkan perbedaan bagian pada ketinggian batang mempengaruhi nilai kuat geser, kuat pegang sekrup, kuat pegang paku, dan modulus elastisitas yang semakin meningkat dari pangkal ke ujung, sedangkan nilai modulus patah meningkat dari pangkal ke tengah lalu menurun ke ujung., Kuto wood (Sterculia macrophylla Vent.) is one of the typical woods of North Maluku, that the trees grow straight in groups and spread from the coast to altitude 0 ̶ 900 masl. There are no scientific reports on the physical and mechanical properties of Kuto wood species harvested from East Halmahera. This study aimed to examine the physical and mechanical properties of Kuto wood in each part (base, middle and tip) so that the wood can be used properly. The mechanical properties were tested using the Instron type 3369 Universal Testing Machine (UTM); the physical properties tested were moisture content, specific gravity, and density. The results showed that the difference in section height of the stem affected the values of shear parallel to the grain, screw withdrawal, nail withdrawal, and MOE, which increased from base to tip, while the MOR value increased from bottom to middle and then decreased to the tip.
Keyword: Kayu Kuto, Sifat Fisis, Sifat Mekanis, Kuto Wood, mechanical properties, physical properties

Judul: Struktur Anatomi dan Sifat Fisis serta Alternatif Tujuan Penggunaan Tiga Jenis Kayu Asal Kalimantan
Abstrak: Wood is a product of living organism that has special characteristic and appearance. Every single species has its own character. Indonesia has about 4000 species of woody plants, but only 95 species have been studied comprehensively. Therefore, study on wood properties is very important not only for determining their proper utilization, but also for better processing and further treatments. Among thousands of existing wood species in Kalimantan, utilization of Belangeran (Shorea Balangeran (Korth.) Buck), Bungur (Lagerstroemia speciosa Pers.) and Medang (Cinnamomum spp.) woods is still limited and has not optimize yet. Through well understanding of their wood characteristics and properties, utilization of these three wood species become more optimize. It was hope that these three woods could be utilized as the alternative to replace the conventional species which tended to decrease year by year. The main material used is a small piece of wood (a disc 5 cm thick) extracted from tree stem at 1.3 meters above the ground from each species. From each disc, wood sample for every measurement was taken representatively following procedural standard. Macroscopic characteristics consist of wood color, figure, texture, grain, lustre, odor and hardness, while microscopic characteristics consist of pore (its arrangement and distribution, perforation plate, pitting structure on the cell wall and contain); ray parenchym (its size, composition and contain); type of axial parenchym and fiber morphology. Microscopic observation was conducted through the maceration specimens of Schlutze and the microtome specimens of Sass. Physical properties of wood consist of moisture content as well as density and specific gravity. The result showed that wood color of three species studied varied: reddish brown in Belangeran, pale brown to reddish in Bungur and yellowish brown in Medang. Heartwood and sapwood demarcation is clearly distinguished only in Belangeran wood, while growth ring is clearly only in Bungur wood. Diffuse pattern of pore was found in Belangeran and Medang woods, while ring porous pattern in Bungur wood. Generally, their vessels are solitary and radially multiple 2-4 cells. Vestured pit, tilosis and axial intercellular channels are the specific characters of Belangeran wood, while Bungur wood are vestured pit and prismatic crystal. Specific characters of Medang wood is yellowish white of amorphous material and oil cell (laticifer). Regarding to pulp and paper raw material, fiber quality of three wood species studied belong to Class III. In term of strengthness, these three wood species are suitable for structural purposes: Belangeran is for Strength Class II, while Medang and Bungur Strength Class III. Belangeran and Bungur woods are also potential as raw material of meubel and furniture.
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Judul: A Continuous Vaccination Strategy in the SVIR Epidemic Model
Abstrak: Vaccination is conducted to minimize the spread of a disease. The vaccination is usually done several times within a fixed time interval. In the SVIR model, it is assumed that individuals do not get immediate immunity following a vaccination program. So according to process of vaccination on SVIR model, there are two strategies, i.e. the continuous vaccination strategy (CVS) and the pulse vaccination strategy (PVS). In this study, only the CVS strategy in epidemic model SVIR is considered. Results of the study indicate that dynamics of the CVS system depends on the basic reproductive number. If the basic reproductive number is less than one, then the disease-free fixed point is asymptotically stable. It means that the disease will eventually disappear from the population. Conversely, if the basic reproductive number is greater than one, then the endemic fixed point is asymptotically stable, which means that the disease will remain exist in the population. Simulation result shows that the vaccination would minimize the spread of disease by reducing the basic reproductive number. If the time for the vaccinated recipients to obtain the immunity, as well as a possibility of vaccinated recipients to be infected are neglected, then the disease will be eradicated. This condition is called an over-evaluating effect of vaccination.
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