Judul: Pengaruh Penggunaan Serat Buah Bintaro (Cerbera manghas) terhadap Sifat Mekanik Beton
Abstrak: Sea mango (Cerbera manghas) known as bintaro in Indonesia is not a popular seed fruit in everyday use. Since people don’t see its benefit, so it has no economic value. The objectives of this research are to calcute the compressive strength and flexural strength from the fiber reinforced concrete with different content variation, analyze the effect of using sea mango as a fiber to concrete, and to determine the best proportion to make a fiber reinforced concrete with sea mango fiber. There are several procedures in this research which are fiber-preparation, aggregates analyzing, calculating the proportion of materials, mixing, and sample-testing. There are 4 variation of fiber’s amount in this research which are 0, 25, 50, and 75 gram from sand’s proportion. The best proportion of sea mango fiber to make a fiber reinforced force in this research is 50 gram. The compressive strength values on concrete which consist of 50 gram amount of sea mango fiber on the 28th day is 13,48 MPa. The flexural strength values on concrete which consist of 50 gram amount of sea mango fiber on the 28th day is 10,67 MPa. Based on these values, sea mango fiber decreseas the concrete’s compressive strength but increases the flexural strength.
Keyword: Bogor Agricultural University (IPB), Sea Mango, Flexural Strength, Fiber, Concrete, Compressive Strength

Judul: Studi penggunaan bambu sebagai bahan tulangan beton
Abstrak: Tujuan penelitian ini adalah untuk melihat sejauh mana jenis-jenis bambu komersial dengan pemberian per- lakuan tertentu dapat dipakai sebagai alternatif penggan- ti besi baja melalui pengkajian aspek teknis. Contoh bambu yang dipakai berupa bambu yang tua, diambil dari Kebun Raya Bogor. Penelitian ini dilakukan di areal lo- kasi Rumah Penelitian Babakan Lebak, Darmaga-Bogor dan di Laboratorium Keteknikan Kayu, Fakultas Kehutanan Institut Pertanian Bogor. Pembuatan adonan beton menggunakan mutu K-125, dan diteliti setelah berumur 28 hari. Rancangan penelitian- nya adalah faktorial acak lengkap 3x4x6 dengan 3 kali ulangan. Faktor A adalah jenis bambu (Al A2 = Bambu Betung, A3 bahan stabilisasi dimensi (B0 = Bambu Andong, Bambu Tali), faktor B adalah = tanpa laburan/kontrol, B1 = parafin, B2 water repellent, B3 = C adalah bentuk profil bambu (C1 coakan 'u', C3 coakan 'z', C4 = vernis) dan faktor polos/kontrol, C2 polos berkawat, C5 coakan 'u' berkawat, C6 coakan 'z' berkawat). = Respon yang diteliti adalah keteguhan mekanis beton bertulangan...
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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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