Judul: Limbah Padatan Penyamakan Kulit Ikan sebagai Material Hierarchical Porous Nanocarbon untuk Aplikasi Supercapacitor
Abstrak: Kulit ikan sebagian besar mengandung kolagen yang dapat dimanfaatkan sebagai kulit tersamakan. Limbah pada proses penyamakan kulit ikan umumnya merupakan limbah cair dengan padatan terlarut yang merupakan sumber material karbon yang sangat besar. Keberagaman dan meningkatnya sifat kelistrikan melalui hierarchical porous nanocarbon menjadikan limbah padatan berpotensi dikembangkan sebagai material untuk aplikasi superkapasitor. Pirolisis suhu 900oC selama 2 jam, aktivasi kimia kalium hidroksida (KOH) 3,5 M dan nanomilling partikel menghasilkan hierarchical porous nanocarbon dengan struktur kristal grafit, luas permukaan 624 m2/g, volume pori 0,4562 cm3/g dan ukuran partikel 170 + 40 nm. Elektroda superkapasitor yang diperoleh memiliki karakteristik konduktivitas elektron 7746,81 + 282,74 S/m dan kapasitansi muatan 380 F/g.
Keyword: hierarchical porous nanocarbon, kulit ikan, penyamakan, superkapasitor

Judul: Pembuatan Nanokarbon dari Limbah Baterai untuk Aplikasi Elektroda pada Superkapasitor
Abstrak: Carbon material is waste battery electrodes for supercapacitors are high potentially, since it has a high surface area, good chemical stability, and high conductivity. These carbon-based electrodes are promising candidates for energy storage devices with high performance is supercapacitor. Supercapacitor which has great potential in the storage of electrical charge, so it can be used as of equivalent fuel oil for motor vehicles, but it also wastes the battery can be recycled, thus reducing the danger of environmental pollution and public. Carbon material waste converted into nano-size batteries using High Energy Milling (HEM), to find out in the form of nano size using Particle Size Analyzer (PSA) produced 148.54 nm particle size. Furthermore, carbon material is a mixed nano size Poly (vinylidene fluoride) Polytetra and 1-methyl-2-pyrrolidone, glued in stainless steel. Results of carbon morfology form characterized using Scanning Electron Microscopy (SEM), crystallinity characterization of structures using X-Ray Diffraction (XRD), with a conductivity value of 7374.00 S/m. This suggests that carbon is a semiconductor material. Results of capacitance value with potentiostat 179.40 F/g for scan rate 5 mV/s.
Keyword: PSA, potentiostat, Carbon waste batteries, HEM, supercapacitor electrodes

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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