• Journal of Environmental Health Sciences
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• v.29 no.1
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• pp.34-42
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• 2003

The objective of this study is to investigate the waste recycling possibility, practicability, economic efficiency and acid gas sorbent use of the hard-shelled mussel. This study is to investigate the hydration/calcination reaction and fixed bed reactor. The physical-chemical characteristics of the hard-shelled mussel were analyzed by ICP SEM-EDX, BET and pore volume. Thus, the results could be summarized as follows; Hard-shelled mussel can be used as iron-manufacture and chemical sorbents considering more than 53.7% of the mussel is lime content. The SO$_2$removal efficiency of the hard-shelled mussel after calcined hydration increased thirty times as a result of the higher pore size, specific surface area and pore volume. Also, the CaO content, pore volume, pore size distribution and specific surface area greatly influenced the SO$_2$ and NOx removal reactivity. The optimum particle diameter average of hard-shelled mussel was $\pm$100 mesh, which was applied to the sorbent on the medium/small scale waste incinerator and flue gas desulfurization processes.

• Journal of the Korea Computer Industry Society
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• v.8 no.1
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• pp.17-22
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• 2007

Carbon nanotubes (CNTs) were grown by a thermal chemical vapor deposition (CVD) method, which has been regarded as one of the most promising candidates for the synthesis of CNTs due to low cost and high growth yield. The Ethylene $(C_2H_4)$, hydrogen $(H_2)$ and Argon(Ar) gases were used for the growth of CNTs at $700^{\circ}C$. As a catalyst for CNTs growth, Fe thin film and Iron nitrate and Molybdenyl acetylacetonate solution with alumina nano-particle were prepared on $SiO_2/Si$ substrate. The growth properties of CNTs were analyzed by SEM and AFM.

• Journal of the Korean Electrochemical Society
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• v.8 no.4
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• pp.168-171
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• 2005

The electrochemical properties of $LiFePO_4$ as a cathode for Li-ion batteries were improved by incorporating conductive carbon into the $LiFePO_4$. X-ray diffraction analysis and SEM observations revealed that the carbon-coated $LiFePO_4$ consisted of fine single crystalline particles, which were smaller than the bare $LiFePO_4$. The electrochemical performance of the carbon-coated $LiFePO_4$ was tested under various conditions. The carbon-coated $LiFePO_4$ showed much better performance in terms of the discharge capacity and cycling stability than the bare $LiFePO_4$. The improved electrochemical performances were found to be attributed to the reduced particle size and enhanced electrical conductivity of the $LiFePO_4$ by the carbon.

• Journal of Powder Materials
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• v.18 no.4
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• pp.347-358
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• 2011

Two different schemes were adopted to fabricate ordered macroporous structures with face centered cubic lattice of air spheres. Monodisperse polymeric latex suspension, which was synthesized by emulsifier-free emulsion polymerization, was mixed with metal oxide ceramic nanoparticles, followed by evaporation-induced self-assembly of the mixed hetero-colloidal particles. After calcination, inverse opal was generated during burning out the organic nanospheres. Inverse opals made of silica or iron oxide were fabricated according to this procedure. Other approach, which utilizes ceramic precursors instead of nanoparticles was adopted successfully to prepare ordered macroporous structure of titania with skeleton structures as well as lithium niobate inverted structures. Similarly, two different schemes were utilized to obtain disordered macroporous structures with random arrays of macropores. Disordered macroporous structure made of indium tin oxide (ITO) was obtained by fabricating colloidal glass of polystyrene microspheres with low monodispersity and subsequent infiltration of the ITO nanoparticles followed by heat treatment at high temperature for burning out the organic microspheres. Similar random structure of titania was also fabricated by mixing polystyrene building block particles with titania nanoparticles having large particle size followed by the calcinations of the samples.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.2
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• pp.152-162
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• 2013

The physico-chemical characteristics and nanostructure of the aerosol samples from a coal-fired power plant, a charcoal kiln and diesel vehicles were investigated with focusing on black carbon (BC). Aerosols from the coal-fired power plant were mostly comprised of mineral ash spheres which are heterogeneously mixed. The main components of the aerosols from coal-fired power plant were calcium compounds, iron oxide, alumino-silicate without BC. The typical combustion-generated BC which shows the shape of bunch of grapes with 20~50 nm particles which were detected in aerosol particles from diesel vehicles. The nanostructure of each BC particle shows the shape of concentric circles which is comprised of closely-packed graphene layers. Aerosols from charcoal kiln were likely condensed organic carbon generated from the low-temperature combustion process.

• Journal of the Korean Applied Science and Technology
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• v.30 no.4
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• pp.726-739
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• 2013

Fischer-Tropsch synthesis (FTS) converts synthesis gas (CO and $H_2$) into longer chain hydrocarbons by a surface polymerization reaction. Cobalt- or iron-based catalysts normally show excellent activity for syngas conversion to petroleum products leading to super clean diesel fuels. The catalytic activities of the catalysts in FTS depend on the number of active sites on the surface. The number of active site was determined by the active metal particle size, loading amount, reduction degree and support-active metal interaction. The investigation adopts new methodology in preparing FT catalyst, which contains the controlled synthesis of active metal. The main focus of this paper is to give an overview of the types of catalysts, also including their preparation and reduction; the types of FT reactors; and also including the reaction conditions.

• Tribology and Lubricants
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• v.27 no.2
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• pp.95-100
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• 2011

The brake disc materials for railway vehicle have been mainly used cast-iron. The brake disc and pad should be light, resist to a thermal crack and absorb enough friction energy. In order to satisfy this requirement, aluminum alloy brake disc for railway vehicle has been newly developed. The aluminum itself has not been considered the friction material for railway vehicle. However, in the case of aluminum composite with dispersed ceramic particles, friction characteristics, resistance to wear and heat are much improved. In the present study, aluminum composite brake disc of 20% ceramic particle and three kinds of organic pads have been tested in dynamometer. The results show that Al MMC brake disc and pad have good friction coefficient and wear rate, and thermal cracks in brake disc have not been initiated. Also, the Al MMC brake disc can be applied to railway vehicle of 150 km/h.

• Journal of Environmental Health Sciences
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• v.17 no.1
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• pp.120-128
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• 1991

Saccharomyces cerevisiae was immobilized by incubating iron oxides with calcium alginate, and by polyacrylamide entrapment to use repeatedly for the conversion of glucose to ethanol. Magnetic and non-magnetic immobilized yeast and polyacrylamide immobilized yeast were compared with the native yeast a batch-fermentation of ethanol from glucose. Three kinds of immobilized yeast tended almost identically, having ethanol productivity as well as the final yield about the same to what was found for the native yeast. The long-term operational stability of three kinds of immobilized yeast were significant difference according as immobilized yeast activation or non-activation before ethanol fermentation. In the non-activation they lost their activity of fermentation rapidly in the beginning stage an slower at a later stage. On the other hand, in the activation with nutrient media, their activities were increased to some extent and stable in the later stage. The cell count of three kinds of immobilized yeast after activiation by incubating nutrient media, increased by a factor of about 45 to 48, whereas the fermenting capacity increased by a factor of 174 to 178. In the prearation of immobilized biocatalysts, magnetic matter does not seem to have any adverse affect on the properties of the microorganism. The immobilized biocatalysts by utilizing magnetic matter have some advantages, especially in application of viscous media or insoluble particle-containing media, for this work was linked with microbial utilization of environmental wastes and elimination of envirnmental pollutant.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.9-18
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• 2001

1. EAF Dust in Japan - Generation and Characteristics. The quantity of dust generated from EAF shops in Japan was estimated to be 520,000 tons/year in 1999. Extremely fine dust (or fume) is formed in the EAF by metal vaporization. Its characteristics such as chemical compositions, phases, particle size, leaching of heavy metal are mentioned. 2. EAF Dust Treatment Methods in Japan. In 1999, 61% of EAF dust was treated by regional zinc recovery processing routes, 25% went to landfill disposal, 4% was reused as cement material, and 10% was treated by on-site processing routes. The problems of EAF dust treatment methods in Japan are: (1) very high treatment cost, and (2) heavy environmental load (leaching of heavy metal, emission of dioxins, depletion of disposal sites, etc). It has been much hoped for that new dust management technology would be developed. 3. New technology of EAF dust treatment in Japan. In Japan, some new technologies of EAF dust treatment have been developed, and some others are in the developing stages. Following five processes are mentioned:. (1) Smelting reduction process by Kawasaki Steel, (2) DSM process by Daido Steel, (3) VHR process by Aichi Steel, (4) On-site dust direct recycling technology, and (5) Process technology of direct separation and recovery of iron and zinc metals contained in high temperature EAF off gas by the Japan Research and Development Center fur Metals.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.209-212
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• 2001

Aircraft industry is developed very fast so titanium scrap was generated to manufacture. Titanium scrap was wasted and used to deoxidize cast iron so we are study recycling of it. In this research were studied that metal hydride of reacted in hydrogen chamber of AMS4900, 4901, return scrap titanium alloy and sponge titanium granule. The temperature of hydrogenation was 40$0^{\circ}C$ in the case of pure sponge titanium but return scrap titanium alloy were step reaction temperature at 40$0^{\circ}C$ and 50$0^{\circ}C$, and after the hydride of titanium alloy were crushed by ball mill for 5h. Titanium hydride contains to 4wt.% of hydrogen theoretically as theory. It was determined by heating and cooling curve in reaction chamber. The result of XRD was titanium hydride peak only that it was similar to pure titanium. Titanium hydride Powder particle size was about 45${\mu}{\textrm}{m}$, and recovery ratio was 95w% compared with scrap weight for a aluminum foam agent.