• Journal of the Korean Ceramic Society
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• v.26 no.2
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• pp.242-248
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• 1989

The powder properties and sinterability of ZrO2-8m/o Y2O3 prepared by coprecipitation were investigated. The specific surface area and the total pore volume were increased with increasing pH of sediment and using of ethyl alcohol for washing. The powders of prepared by freeze drying method were showed the smallest particle size and lowest agglomerate rate, and the powders obtained from spray drying method were showed porous structure. At 130$0^{\circ}C$, their relative density were 94-96%, so these sintered bodies have revealed high sinterability in spite of low sintering temperature.

• Journal of the Microelectronics and Packaging Society
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• v.26 no.4
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• pp.107-111
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• 2019

We report the fabrication of a CdS/CuInGaSe (CdS/CIGS) structure with carbon nanotubes and its application as a photocathode for photoelectrochemical water splitting. CIGS thin films were fabricated using co-evaporation by RF magnetron sputtering, while CdS was fabricated by chemical bath deposition. Spray coated multi-wall carbon nanotube (CNT) film on CdS/CIGS thin film was investigated as a photocathode. The CNT-coated CdS/CIGS showed superior photocurrent density and exhibited improved photostability.

• Aerospace Engineering and Technology
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• v.1 no.1
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• pp.128-134
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• 2002

Outer surfaces of KSR-III are insulated to protect outer structure and inner payloads from the aerodynamic heating. The characteristics of insulation material (BMS 10-102), selected through careful tests and thermal analyses, are low heat transfer rate and low density. It is applied in a wet and continuous spray pattern for outer surfaces of KSR-III. In the present study, the honeycomb sandwich structure of nose fairing, which is one of the typical multi-layer structures of KSR-III, is thermally analyzed with insulation.

• Preventive Nutrition and Food Science
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• v.18 no.4
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• pp.292-295
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• 2013

Fermented whey solution presenting bifidogenic growth stimulation (BGS) activity was processed as prototypes such as sterilized fermented whey (SFW), spray-dried fermented whey (SDFW), and freeze-dried fermented whey (FDFW) and their BGS activities were compared. In optical density ($OD_{600}$) test, the BGS activity of three prototypes, which showed similar activities, were significantly different with non-fermented whey solution adjusted to pH 4.5 as a control (P<0.05). In viable cell count test, SDFW had the most positive influence than other prototypes on the BGS activity even though the difference was not significant. However, the activities of all prototypes were significantly different than the negative control (no addition). These results indicate that the processed prototypes of fermented whey solution show BGS activities and might be commercialized, with further evidences, in animal or human studies.

• Journal of Surface Science and Engineering
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• v.49 no.2
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• pp.172-177
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• 2016

In this paper, various electrochemical experiments were conducted in seawater solution to evaluate corrosion damage behavior of arc thermal sprayed Inconel 625 coating on SS400 steel in marine environment. As a result, corrosion damages of thermal sprayed Inconel 625 coating preferentially occurred at the defect area, and they were observed as a form of pitting corrosion in the galvanostatic experiments. In Tafel analysis, corrosion current density of Inconel 625 coating was relatively high due to influence of interconnected pores and Cr oxides in the thermal spray coating layer. On the other hand, the result of the potential measurement, thermal sprayed Inconel 625 coating should need the post-treatment which can compensate the defects like pores and cracks because Inconel 625 coating presented a higher potential of about 290 mV than that of the SS400 steel.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.610-616
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• 1997

One of the notable changes in Korean Industry in 1990's was globalization. Many of Korea plants have been built In the foreign countries and many of foreign plants have been build in Korea. And it is believed that many foreign insurance companies will begin their business in Korea soon, as Korea will open their insurance market to them. While sprinkler system plays very important role in total fire protection system, Korean sprinkler system design has not been studied in depth. Thus, it is not easy to convince the performance of Korean sprinkler system and compare it to NFPA 13, Standard for the Installation of Sprinkler System. Design guideline from both system will be listed and compared in detail. Fire water demand from both system will be reviewed to evaluate its adequacy. Water spray density and actuation time will be estimated, too.

• Journal of ILASS-Korea
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• v.24 no.2
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• pp.66-72
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• 2019

Diesel vehicles suffer from poor starting and running problems at cold temperatures. Diesel vehicles have the characteristic that CO and PM are reduced or similarly discharged when going from low temperature to high temperature. In this study, a bypass type piezo injector for electronic control based common rail injection system was used. Numerical analysis using injector drive analysis model was performed to analyze injector drive and internal fuel flow characteristics according to fuel temperature change. The results show that the rate of density change due to the fuel temperature is proportional, and that the effect of the kinematic viscosity is relatively large between $-20^{\circ}C$ and $0^{\circ}C$. Comparing the results of temperature condition at $0^{\circ}C$ and $20^{\circ}C$, it is considered that the viscosity is more correlated with the needle displacement than the pressure chamber of the delivery chamber.

• Journal of Surface Science and Engineering
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• v.50 no.5
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• pp.366-372
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• 2017

Plasma electrolytic oxidation(PEO) has attracted attention as a surface treatment which has high wear resistance and corrosion resistance. PEO is generally considered as cost-effective, environmentally friendly and superior in terms of coating performance. Most of studies about the PEO processes have been applied to light metals such as Al and Mg. Because the strength of Al and Mg is weaker than that of steel, there is a limit to the application. In this study, PEO process was used to form oxide coatings on Hot dipped aluminized(HDA) steel and the characteristics of the coating film according to the PEO current density were studied. The morphology was observed by SEM and component was analyzed by using EDS. The corrosion behaviors of PEO coating films were estimated by exposing salt spray test at 5 wt.% NaCl solution and measuring polarization curves in deaerated 3 wt.% NaCl solution. With the increase of PEO process current density, the pore size of the coating surface and the thickness of coating increased. It was confirmed that no Fe component was present on the coating surface. PEO coating films obviously showed good corrosion resistance compared with HDA. It is considered that the PEO coating acts as a barrier to protect the base material from external factors causing corrosion.

• Fire Science and Engineering
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• v.16 no.1
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• pp.66-76
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• 2002

This paper includes new nozzle design, basic design factors of water mist system that minimize a thermal damage of cable causing business interruption and applying underground utility tunnel. A underground concrete structure (2.5 m(H)$\times$2.5 m(W)$\times$25 m(D)) is constructed in order to test a nozzle performance. Under the designing fire scenario, critical thermal damage of cable sheath ($400^{\circ}c$) reached within a 2 minutes with unsuppressed fire, but type 1 nozzle (SMD 470 $\mu{m}$) and type 2 nozzle (SMD 650 $\mu{m}$) control cable temperature below $400^{\circ}c$. A system performance and fundamental design factors; K factor, flow rate, spray angle, size distribution, nozzle pressure, spray density are analyzed and proposed for system optimization.

• Applied Biological Chemistry
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• v.36 no.6
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• pp.416-423
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• 1993

Milk powders were made by several drying methods and raw materials, and rheological properties of milk powders were investigated by an Instron Universial Testing Machine. The results obtained are summarised as follows. Bulk density of the drum dried whole milk powder was $0.382\;g/cm^3$ and was higher than that of other milk powders. The Hausner ratio, angle of repose and compressibility of the spray dried skim milk powder were 1.127, $32.5^{\circ}$ and 0.029 respectively. This result indicated that skim milk powder showed free flowing characterristics. The compressibility of the drum dried whole milk powder was decreased by the decrease of moisture content. Compressibility of the milk granule was 0.056 and was lower than that of milk powder. The spray dried milk powder of a grobular shape had higher solidity than the freeze or drum dried milk powder. The drum dried milk powder particles consist of irregular shape.