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Your search keyword '"Park, Don-Hee"' showing total 229 results
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229 results on '"Park, Don-Hee"'

1. Physical and Chemical Characterization of Collagen/Alginate/Poly(Vinyl Alcohol) Scaffold with the Addition of Multi-Walled Carbon Nanotube, Reduced Graphene Oxide, Titanium Dioxide, and Zinc Oxide Materials.

Author

Fajarani, Rusyda, Rahman, Siti Fauziyah, Pangesty, Azizah Intan, Katili, Puspita Anggraini, Park, Don-Hee, and Basari

Abstract

Bone damage is one of the main causes of disability in humans, and tissue engineering technology by applying biomaterial-based scaffold has been developed as an effective solution. This can be achieved using various natural and synthetic polymers combined with carbon-based and metal-oxide materials. Therefore, this study aimed to develop bone scaffold using collagen, alginate, and poly(vinyl alcohol), with the addition of multi-walled carbon nanotube, reduced graphene oxide, titanium dioxide, and zinc oxide materials. Scaffold was fabricated with the freeze-drying method and characterized physicochemically by observing the morphology through scanning electron microscopy (SEM), identification of functional groups by Fourier transform infrared spectroscopy (FTIR), compressive mechanical properties, porosity, and degradation rate. The results showed that each group of scaffold had a compact structure, with a small pore size and less than 50% porosity. The functional groups of each material were detected, and the compressive strength matched the trabecular bone, approximately 6 MPa. However, the scaffold lacked appropriate porosity and a fast degradation rate exceeding 35% in 7 days. [ABSTRACT FROM AUTHOR]

Published
2024
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17. Nicotine extraction from tobacco leaves in tubular extractor.

Author

Tjokrosoedomo, Muhammad Ryo, Muharam, Yuswan, Park, Don-Hee, and Gozan, Misri

Subjects
TOBACCO, TOBACCO smoke, NICOTINE, RAW materials, TOBACCO use, ALKALOIDS, CIGARETTES, INSECTICIDES
Abstract

Tobacco has one of the largest plantation areas in Indonesia, especially for cigarette raw material. With Framework Convention on Tobacco Control coming in 2003 on a global scale and several government rules about cigarette control on a national scale, some works are needed to prevent the decrease of farmer's earning. One of the things that can be done is using tobacco as a raw material for other products, such as pesticides. Tobacco waste has 0.6 - 4 percent nicotine sulfate which is an effective insecticide. Nicotine inside tobacco is a strong neurotoxin that can work really fast and very effective on insects and molds. Nicotine extraction is conducted using ethanol as a solvent in a tubular extractor. The extraction process is done in a bed with 30 cm height and 3 cm diameter for 100 minutes with sampling every 20 minutes on 0.5 mL/minute, 1 mL/minute, and 3 mL/minute solvent flow rate as well as 0.45 mm and 0.9 mm particle diameter variation. Nicotine that is produced from the extraction process is analyzed using HPLC to get the yield from that extraction process. HPLC testing shows that the extraction optimal yield is 10.88 mg, on 1 mL/minute solvent flow rate and 0.45 mm particle diameter. [ABSTRACT FROM AUTHOR]

Published
2022
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