Judul: Karakterisasi Fisik, Mekanik, dan Termal pada Berbagai Komposisi Material Coco-conblock (Beton Serat Sabut Kelapa) Untuk Dinding
Abstrak: Penelitian ini bertujuan untuk mengetahui rasio penggunaan sabut kelapa yang optimal dan mutu yang diperoleh sebagai bahan penyusun beton serat dengan menguji sifat fisik, mekanik, dan termalnya. Perbandingan semen dan pasir yang digunakan ialah 1:3 dan 1:5 dengan variasi konsentrasi penambahan serat sebesar 0%; 10%; 20%; 30%; dan 40% terhadap massa semen. Benda uji untuk pengujiannya berbentuk balok dengan ukuran berkisar 16 x 4 x 4 cm. Pengujian dilakukan pada benda uji berumur 3, 7, dan 28 hari. Hasil pengujian menunjukkan bahwa dengan penambahan serat serabut kelapa menyebabkan penurunan nilai kuat tekan sebesar 30-80% dan kuat lentur sebesar 30-66%. Proporsi serat 10% menghasilkan nilai tertinggi dibandingkan beton dengan konsentrasi serat lainnya. Coco-conblock mampu menghemat pemakaian energi 7-44% dibandingkan batu bata.
Keyword: Beton serat, serat sabut kelapa, sifat fisik, sifat mekanik, dan sifat termal

Judul: Karakteristik Fisik, Mekanik dan Termal Papan Partikel Sabut Kelapa (Cocos nucifera L.) Berlapis Bambu Betung (Dendrocalamus asper sp.) Sebagai Material Bangunan
Abstrak: Demand of woods as raw materials in the industry are more than the availability, therefore research is needed to develop the other alternatives to substitute the woods as the primarily raw material. In this case, the aim of this research are to construct particle boards made of coco fiber and betung bamboo and to research their physical, mechanical and thermal characteristics. Physical characteristics of particle board have qualified the particle board standards, that are: density 0.79 cm3/g, moisture content 13.88 %, and water absorption 40.1%, except the thickness swelling percentage reached 15.18%. The mechanical characteristics of particle board have qualified the JIS A 5908-2003 and SNI 03-2105-2006 standards, that are: tensile strength 137.57 kgf /cm2, compressive strength 87.44 kgf/cm2, Modulus of Elasticity (MOE) 24970.46 kg/cm2, screw-withdrawal strength 105.81 kgf, and internal bond 2.54 kgf/cm2, except the Modulus of Rupture (MOR) value that only reached 21.10 kg/cm2. This study also reveals that using particle boards made of coco fiber and bamboo betung as storage walls are less capable to prevent the oven heats which is proven by the increasing of temperature of taro inside the storage box along the increasing of temperature of the oven.
Keyword: betung bamboo, coco fiber, mechanical characteristics, particle boards, physical characteristics

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