Judul: Sifat Fisis dan Mekanis Papan Komposit Plastik dari Limbah Kelapa Sawit dan Plastik Polipropilena
Abstrak: Plastic composite board is a composite board made from plastic as a matrix and oil palm waste powder as filler, which has properties of both. The objectives of this research are to determine physical and mechanical properties of wood plastic composite. The used treatments of this research are filler sources (the wastes of palm tree stem, shell and empty fruits bunch fiber) and particle sizes (20, 40, and 60 mesh). The evaluation of physical and mechanical properties was based on JIS A 5908 (2003), and the research results showed that: (1) moisture content was 2.43%, (2) water absorption for 24 hours was 7.41%, (3) thickness swelling of 24 hours was 3.64%, (4) modulus of elacticity (MOE) was 10.38 x 103 kg/cm2, (5) modulus of rupture (MOR) was 164 kg/cm², and (6) internal bond (IB) was 0.17%. The physical and mechanical properties of wood polymer composite met the criteria of JIS A 5908 (2003), except the modulus of elasticity and internal bond.
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Judul: Kualitas Papan Komposit Plastik dari Limbah Kelapa Sawit (Elaeis guineensis Jacq) dan Polipropilena Daur Ulang
Abstrak: Wood plastic composite can be produced using oil palm waste as filler and recycled polyprophylene as a matrix. The objective of this research is to determine the quality of wood plastic composite board based on physical and mechanical properties. The treatments of this research are filler sources (the wastes of palm tree stem, shell and empty fruits bunch fiber) with different utilization levels of compatibilizer maleic anyhydride (MAH) and benzoil peroxide (BPO) as iniciator. Testing of physical and mechanical properties based on Japanese Industrial Standard (JIS) A 5908 (2003) for particle board. The research results showed that average value of density was 0.79 g/cm3, average value of moisture content was 2.59%, average value of water absorption for 24 hours was 8.51%, average value of thickness swelling of 24 hours was 2.50%, average value of modulus of elacticity (MOE) was 11.45x103 kg/cm2, and average value of modulus of rupture (MOR) was 144.75 kg/cm². The physical and mechanical properties of wood polymer composite met the criteria of JIS A 5908 (2003), except the modulus of elasticity.
Keyword: benzoil peroxide (BPO), maleic anhydride (MAH), recycled polypropylene (RPP), oil palm waste, wood plastic composite

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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