Judul: Biokomposit filler nanopartikel serat kulit rotan sebagai material pengganti komposit sintetis fiber glass pada komponen kendaraan bermotor
Abstrak: The technology of bionanocomposite development in Indonesia had a good prospects. This is due to the availability of natural resources, especially agricultural products and waste which abundant and can be obtained throughout the year. The rattan bark is one of the agricultural waste that could be used as a source of fiber for bionanocomposite. The objective of this study was to synthesize and characterize bionanocomposite of polypropylene reinforced cellulose nanoparticles of rattan to be used to replace glass fiber as a filler in the composite. Cellulose was made of rattan bark in the form of nanoparticles by mechanical milling method, shaking, heating and ultrsonication in liquid media. These nanoparticles was used as a bionanocomposite filler which was prossesed by injection molding method with variation of concentration from 2% - 20%. The XRD result from the nanoparticles bark of rattan showed β-cellulose phase with monoclinic structure and crystal structure at 2θ = 220 (002). The density of nanoparticles was 0.2492 g cm-3 Keywords: Cellulose, extraction, nanoparticles, biodegradable, ultrasonication, . The surface morphology was elongated like a hollow cylinder. The size of the nanoparticles was 20 nm (TEM testing) with a homogeneous distribution volume of 32 %. Results from EDS and AAT indicated that bionanocomposite comprise of C, H and O as well as minerals Ca, K, Si. The mechanical properties from bionanocomposite of polypropylene reinforced cellulose nanoparticles of rattan was optimum at filler concentrations of 5%. The properties that comparable to synthetic composites were modulus of elasticity, hardness, tensile breaking elongation while, flexural strength and tensile yield strength were lower. This was due to the aglomeration in some areas so that the filler interphase bond was not optimal.
Keyword: 

Judul: Pemanfaatan Kulit Rotan sebagai Filler Bionanokomposit pada Aplikasi Fan Cover Comp Sepeda Motor
Abstrak: The resesarch has been conducted to obtain the optimization of process parameters to synthesize nanoparticle as bionanocomposite filler made from rattan peel waste with polypropilane matrix on fan covercomp motorcycle application. Variations of milling time used in manufacturing process of nanoparticles are 15 minutes, 30 minutes, and 45 minutes using Hammer Mill machine. The distribution of the smallest particle were gained in sample 2 with an average size of 24.35 nm. Manufacturing bionanocomposite using filler were gained from sample 2 (15 minutes). Filler used in the manufacture process of bionanocomposite is 5%, based on the research that has been done before. The quality of rattan peel fibers based on impact strength and hardness test exceeds the HES which using PPFG synthetic composite. Bionanocomposite density test value is equal to 0.84 g cm-3 and PPFG synthetic composite is 1.03 g cm-3. Based on the characteriztion showed that the nanoparticles rattan fibers are suitable for use as a filler of composite material fan covercomp motorcycle.
Keyword: rattan peel., polypropilane, nanoparticle, fan covercomp, bionanocomposite

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.
Keyword: