• Applied Biological Chemistry
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• v.13 no.2
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• pp.131-151
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• 1970

A new method of plastic film coating has been investigated to extend storage life of apples. The film coating was effected by dipping fresh apples in a plastic emulsion. The effect of plastic film coating on the preservation of freshness, respiratory activities and chemical components during storage, has been investigated on four leading varieties of apples. The results are summarized as follows: 1. The effect of film coating on storage life of apples was apparent, resulting in delay of after-ripening, shriveling, softening or physiological impediment as well as reducing consumption of reserve materials and waste fruits. 2. Change in the partial pressure of gas, i.e., increase in carbon dioxide and decrease in oxygen in apple tissue was resulted by the plastic film coating, suggesting that the film deposited on the fruit interfered with the diffusion of gases formed therein. 3. The effects of plastic film coating on the fruit storage varied with the type of plastic emulsions, coating temperature, varieties of apples and degree of fruit ripening. As regard to apple varieties, good results were obtained with PVA 217 for both American Summer Pearmain and Jonathan, and PVC 443 for McIntosh. 4. Reduction in the diminution rates of L-malic acid, ascorbic acid and soluble pectin etc. during storage of apples may account for the improved storage life of the fruits treated with plastic films.

• Tribology and Lubricants
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• v.25 no.1
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• pp.7-12
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• 2009

Coating brittle intermetallic compounds on metal can enlarge the range of their use. It is found that intermetallic compound coating layers made by only combustion synthesis in an electric furnace have porous multi-phase structures containing several intermediate phases, even though the coating layers show good wear resistance. In this study, dense $Ni_{3}Al$ single phase layer corresponding to the initial composition of the mixed powder is coated on two different ferrous materials by the diffusing treatment after combustion synthesis. After- ward, sliding wear behaviors of the coating layer are evaluated in comparison with that of the coating layer with porous multi-phase structure made by only combustion synthesis. As a result, the wear properties of the coating layer composed of dense $Ni_{3}Al$ single phase are considerably improved at the range of low sliding speed com- pared with that of the coating layer with porous multi-phase structure, particularly in the running-in wear region. This is attributed to the fact that wear of the coating layer is progressed by shearing as a sequence of adhesion, not by occurring of pitting on the worn surface due to having dense structure without pores.

• Corrosion Science and Technology
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• v.7 no.4
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• pp.233-236
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• 2008

Halide-activated pack cementation was utilized to deposit B-doped silicide coating. The pack powders were consisted of $3Wt.c/oNH_4Cl$, 7Wt.c/oSi, $90Wt.c/oAl_2O_3+TiB_2$. B-doped silicide coating was consisted of two layers, an outer layer of $NbSi_2$ and an inner layer of $Nb_5Si_3$. Isothermal oxidation resistance of B-doped silicide coating was tested at $1250^{\circ}C$ in static air. B-doped silicide coating had excellent oxidation resistance, because continuous $SiO_2$ scale which serves as obstacle of oxygen diffusion was formed after oxidation.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.113-114
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• 2023

This study measured the thickness and speculation coefficient of the coating for existing buildings and calculated the diffusion coefficient of the coating to predict the depth of carbonation through numerical analysis in order to evaluate the impact of the external finish and local environment. As a result, it was possible to predict the short-term and long-term carbonation depth of reinforced concrete buildings coated with coating film with considerable reliability.

• Bulletin of the Korean Chemical Society
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• v.32 no.3
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• pp.852-856
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• 2011

The lithium ion diffusion coefficients of bare, carbon-coated and Cr-doped $LiFePO_4$ were obtained by fitting the discharge curves of each half cell with Li metal anode. Diffusion losses at discharge curves were acquired with experiment data and fitted to equations. Theoretically fitted equations showed good agreement with experimental results. Moreover, theoretical equations are able to predict lithium diffusion coefficient and discharge curves at various discharge rates. The obtained diffusion coefficients were similar to the true diffusion coefficient of phase transformation electrodes. Lithium ion diffusion is one of main factors that determine voltage drop in a half cell with $LiFePO_4$ cathode and Li metal anode. The high diffusion coefficient of carbon-coated and Cr-doped $LiFePO_4$ resulted in better performance at the discharge process. The performance at high discharge rate was improved much as diffusion coefficient increased.

• Solar Energy
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• v.10 no.1
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• pp.57-62
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• 1990

The influence of substrate materials on the thermal stability of black chrome coating was investigated by Rutherford backscattering spectrometry(RBS). In order to study thermal degradation the sample were annealed in air for 24 hour at temperature of 450. Cu, Ni, and S.S(Stainless steel 304) were used as substrate for selective coating. The experimental results of substrate diffusion was discussed. It was found that little diffusion of substrate material occurred for the sample pre. pared on stainless steel.

• Journal of the Korean Solar Energy Society
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• v.34 no.4
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• pp.39-44
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• 2014

The elemental composition of electro-deposited black Cr solar selective coatings before and after heating in air by using secondary ion mass spectrometry (SIMS) was investigated for optical property analysis. In addition, black Cr selective coating exposed by solar radiation for 5 months was compared with heated sample. SIMS investigation shows that $OH^+$ bearing ions were related to a near surface region of CrOH and CrO compound. The optical degradation of this coating after heating at $500^{\circ}C$ reveals that diffusion of the Cu and Ni elements in substrate material, the chemical interactions adjacent to the interface, and the interface width broadening.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.2
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• pp.147-152
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• 2002

Carbon nitride thin films were deposited by reactive sputtering for the hard coating materials on Si wafer and tool steels. When the nitrogen content of carbon nitride film on tool steel is 33.4%, the mean hardness and elastic modulus are 49.34 GPa and 307.2 GPa respectively. The nitrided or carburised surface acts as the diffusion barrier which shows better adhesion of carbon nitride thin film on the steel surface. To prevent nitrogen diffusion from the film, steel substrate can be saturated by nitrogen forming a Fe$_3$N layer. The desirable structure at the surface after carburising is martensite, but sometimes, due to high carbon content an proeutectoid Fe$_3$C structure may form at the grain boundaries, leaving the overall surface brittle and may cause defects.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.62-65
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• 2003

In this study, to confirm corrosion of reinforced concrete affected by carbonation, chloride ion diffusion, absorption ratio, air permeability, measured carbonation velocity coefficient, chloride ion diffusion coefficient, absorption coefficient, air permeability coefficient. Corrosion velocity under environment of complex deterioration. And than compared corrosion velocity with these coefficients. As the results of this study, the correlation coefficient between chloride ion diffusion coefficients and absorption coefficient was revealed that it is very high. As well, an increase in carbonation, chloride ion diffusion also increases corrosion velocity. It showed that corrosion velocity was affected by the carbonation, chloride ion diffusion, absorption ratio, air permeability. Generally, data on the development of these coefficient made with none, organic B, organic A, inorganic B, and inorganic A is shown. It showed that coating of surface prevent steel bar from deteriorating.

• 연구논문집
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• s.33
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• pp.175-182
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• 2003

In this study, the wear resistance of the complex powder diffusion treated KS STD 61 has been investigatived. KS STD 61 tool steel was pretreated in quenching and tempering processes to obtain the tempered martensitic microstructure. The samples were packed with complex powder in steel pot($\Phi$90x60mm) and heated in a box furnace. the complex powder diffusion treatment are carried out at $540^{\circ}C$, $520^{\circ}C$, $500^{\circ}C$ for 40min, 1.5hr and 2.5hr. The microstructure, microhardness, wear resistance, and coating layer thickness of the complex powder diffusion treated samples were investigation. The weight loss of as heat treated sample was 0.4mg and that of the complex powder treated at $540^{\circ}C$ for 2.5hr was 0.17mg. These result means that the wear resistance of tool steels can be easily improved by the powder diffusion process at conventional tempering treatment temperature.