• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.26 no.10
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• pp.491-496
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• 2014

In general, the entire air supply of a bio-safety laboratory (BSL) should be exhausted on the outside to ensure bio-safety, and the air conditioning system should always be operated to maintain a difference in the room pressure. As a result, the annual energy consumption of such a building is approximately five or ten times higher than that of an office building of the same magnitude. Thus, this study applies an actual operating system that targets BSL. The energy consumption is analyzed using the Energy Plus V8.0 program (an energy analysis program), and five kinds of cases that depend on the energy consumption of the basic BSL system are also analyzed. As a result, the energy consumption in Case 1 (basic system) is of 324.95 GJ. When the basic system of Case 1 is compared to that in Case 2 (basic system+passive design with exterior envelopes), an annual energy savings of is 6.9% is achieved. For Case 3 (basic system+Photovoltaic, PV) 12.7% is achieved, and for Case 4 (Solar Geothermal Hybrid System of renewable energy, SGHS) 49.5% is achieved. If a passive design with exterior envelopes and renewable energy system (PV+SGHS) is combined, as in Case 5, the energy consumption would be 118.15 GJ. Therefore, when this last system is compared to a basic system, the passive design with exterior envelopes and renewable energy system (PV+SGHS) can reduce energy consumption by 63.6%.

• Food Science of Animal Resources
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• v.33 no.4
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• pp.501-507
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• 2013

Lysozyme was trapped from $2{\times}$ diluted egg white using Amberlite FPC 3500 ion exchange resin (1 g/10mL of egg white). The lysozyme bound to the resin was recovered using 0.1 N glycine-NaOH buffers, pH 9.0, containing 0.5 M NaCl. After separating lysozyme, the pH of the egg white solution was adjusted to 4.75 and centrifuged to remove interfering proteins. The supernatant was collected, added with 2.5% citric acid and 5.0% ammonium sulfate combination to precipitate egg white proteins, except for ovalbumin. After centrifugation, both supernatant (S1) and precipitant were collected. The precipitant was dissolved with 4 volumes of distilled water, and then 2.0% ammonium sulfate and 1.5% citric acid combinations added, stirred overnight in a cold room, and centrifuged. The resulting supernatant (S2) was pooled with the first supernatant (S1), desalted using an ultrafiltration unit, heat-treated at $70^{\circ}C$ for 15 min, and then centrifuged. The supernatant was collected as an ovalbumin fraction and lyophilized. The separated proteins were confirmed using Western blotting. The yield of lysozyme and ovalbumin was > 88.9% and > 97.7%, respectively, and the purity of lysozyme and ovalbumin was > 97% and 87%, respectively. The results indicated that the protocol was simple, and separated lysozyme and ovalbumin effectively.

• Fire Science and Engineering
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• v.33 no.4
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• pp.83-88
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• 2019

This study examined the concentration of combustion gases while considering low ventilation and respiration frequency. A one-quarter-size ISO 9705 room corner test was performed. The concentrations of carbon monoxide and oxygen were measured in each case with the continuous inhalation of combustion gas with low ventilation (2, 6, and 10 LPM) and different respiration frequencies (2 s, 5 s, and infinity). The combustion of a gasoline pool fire in the compartment had a theoretical heat release rate of 5.34 kW. The results show that the deviation of the gas concentrations becomes higher as the low ventilation increases compared to the respiration frequency. In addition, as the respiration frequency increases, the variation in the minimum oxygen concentration is larger than the average value, while in the case of carbon monoxide, the variation in the average value is larger than the maximum value. These results show that the inhalation characteristics of refugees should be considered to investigate fires.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.208-208
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• 2013

Graphene has emerged as a fascinating material for next-generation nanoelectronics due to its outstanding electronic properties. In particular, graphene-based field effect transistors (GFETs) have been a promising research subject due to their superior response times, which are due to extremely high electron mobility at room temperature. The biggest challenges in GFET applications are control of carrier concentration and opening the bandgap of graphene. To overcome these problems, three approaches to doping graphene have been developed. Here we demonstrate the decoration of Ni nanoparticles (NPs) on graphene films by simple annealing for p-type doping of graphene. Ni NPs/graphene films were fabricated by coating a $NiCl2{\cdot}6H2O$ solution onto graphene followedby annealing. Scanning electron microscopy and atomic force microscopy revealed that high-density, uniformly sized Ni NPs were formed on the graphene films and the density of the Ni NPs increased gradually with increasing $NiCl2{\cdot}6H2O$ concentration. The formation of Ni NPs on graphene films was explained by heat-driven dechlorination and subsequent particlization, as investigated by X-ray photoelectron spectroscopy. The doping effect of Ni NPs onto graphene films was verified by Raman spectroscopy and electrical transport measurements.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 1999.05a
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• pp.5-5
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• 1999

A novel process is proposed to improve oxidation resistance of Ti-Al intermetallic compounds at elevated temperatures by both Cr addition and pre-sulfidation, where TiAl alloys withlor without Cr addition were sulfidized at 1173K for 86.4ks at a 1.3 Pa sulfur partial pressure in a $H_2-H_2S$ gas mixture. The pre-sulfidation treatment formed a thin Cr-Al alloy layer as well as 7~10 micrometer $TiAl_3$ and $TiAl_2$ layer, due to selective sulfidation of Ti. Oxidation resistance of the pre-sulfidation processed TiAl 4Cr alloy was examined under isothermal and heat cycle conditions between room temperature and 1173K in air. Changes in $TiAl_3$ into $TiAl_2$ and then TiAl phases as well as their effect on oxidation behavior were investigated and compared with the oxidation behavior of the TiAl-4Cr alloy as TiAl and pre-sulfidation processed TiAl aHoys. After oxidation for up to 2.7Ms a protective $Al_2O_3$ scale was formed, and the pre-formed $TiAl_3$ changed into $TiAl_2$ and the $Al_2Cr$ phase changed into a CrAlTi phase between the $Al_2O_3$ scale and $TiAl_2$ layer. The pre-sulfidation processed TiAl-4Cr alloy had very good oxidation resistance for longer times, up to 2.7 Ms, in contrast to those observed for the pre-sulfidation processed TiAl alloy where localized oxidation occurred after 81 Oks and both the TiAl and TiAl-4Cr alloys themselves corroded rapidly from the initial stage of oxidation

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.4
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• pp.362-368
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• 2018

There is increased consumer demand for roasted seasoned laver Pyropia yezoensis, processed in various ways. The antioxidative activity of roasted seasoned laver was evaluated at different storage times and the quality of the roasted seasoned laver was improved. The laver was also heated at different temperatures for 3 seconds: $340^{\circ}C$ (SH340), $345^{\circ}C$ (SH345), $350^{\circ}C$ (SH350) and commercial roasted seasoned laver (D) was used as standard. The samples were stored in a transparent acrylic case ($39{\times}27{\times}18cm$) at room temperature for 10 weeks. The total phenolic content began to decrease after 7 weeks of storage and was 395.2, 386.4, 395.8 and $416.4{\mu}g/100g$ for SH340, SH345, SH350 and D, respectively. The respective DPPH (1,1-diphenyl-2-picryl-hydrazyl) radical scavenging activity after 7 weeks of storage were 48.6%, 49.5%, 47.7% and 46.1%. The ferric reducing antioxidant power (FRAP) decreased rapidly after 7 weeks of storage due to the influence of sulfate groups. Therefore, the appropriate storage period and packaging method should be established based on these results.

• Journal of architectural history
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• v.13 no.4 s.40
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• pp.19-34
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• 2004

This study examines the dwellings of the Korean diaspora in Maritime Provinces of Russia, and Kazakhstan and Uzbekistan of Central Asia to find the gist of the residence transformed as Korean traditional residence culture to accept Russian foreign culture. Through the examination, transformation process of the dwellings of the Korean diaspora was found as follows: - 1st Period(1864-1937): The Korean diaspora who Immigrated to Maritime Provinces of Russia built traditional houses of Korean style and few of them lived in Russian style houses. - 2nd Period(1937-1955): The Koreans who immigrated to Central Asia from Maritime Provinces under compulsion built 'ground house' by digging the earth and installed gudeul which is a traditional Korean heating system and roofed with reed. - 3rd period(1955-1991): The Koreans built straight lined '-' shape houses with two or three rooms wherein most of them were installed with gudeul to heat the room. Around the 1940s as they economically got well, the Koreans started to build houses with Russian style with one or two rooms with gudeul or a separate building with gudeul. - 4th period(1991-present): Houses of the 3rd period are still used by being enlarged or remodeled with less use of gudeul which is well reflected on Ujeong-maul village in Russia Maritime Provinces. As can be found above, the dwellings of the Korean diaspora in Russia Maritime Provinces and Central Asia are on the process of being transformed into Russian style to adapt to Russian culture.

• The KSFM Journal of Fluid Machinery
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• v.19 no.4
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• pp.35-38
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• 2016

A PFA lined ball valve, which is machined with fluorinated resin PFA to its inner part for improving corrosion resistance, non-stickness, heat-resistance, has been widely used in semiconductor/LCD manufacturing processes with the high purity chemicals as working fluid. Due to the safety concerns, the experiments for measuring the flow coefficient of a PFA lined ball valve should be conducted with water at room temperature according to IEC standards. However, it is required to know the real flow coefficient with the real working fluid, because the flow coefficient is critical to correctly design valves in piping system. In this study, we calculated the flow coefficient of a PFA lined ball valve 40A with hydrochloric acid ($40^{\circ}C$ 36% HCl) as the working fluid using a commercial CFD package, ANSYS CFX v15. The computational results had a good agreement with the measured data and showed a little difference between water and hydrochloric acid as the working fluid of a PFA lined ball valve.

• KSBB Journal
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• v.15 no.6
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• pp.600-604
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• 2000

Low density polyethylene(LDPE) film was fabricated with the addition of synthetic ceramic which contained a natural antimicrobial agents. The antimicrobial agents used were isolated from culture broths of methylotropic actinomycetes strains MO-16 and MO-17, and Streptomyces sp. No. 31, which was newly isolated from soils as an antifungal agent. Four-day old culture broth of Streptomyces sp. No. 31 showed strong antifungal activity against Aspergilus niger, a test strain, and retained antimicrobial activity after heat treatment at $121^{\circ}C$ for 15 min. The ceramic LDPE film reduced the growth of total aerobic bacteria in packaged minced pork compared with commercial film. The film revealed a 40 to 50% growth inhibition of E. coli on a contained agar plate. In the storage testing of various packaged foods at room temperature for 30 days, the ceramic LDPE film showed excellent preservation compared with commercial film.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.4
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• pp.429-438
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• 2011

In this paper, experiment of thermal conductivity among thermal properties for CCS insulation material was carried out under the condition ranged from room temperature to cryogenic temperature. CCS insulation system should be sustained under cryogenic temperature($-163^{\circ}C$), and lots of investigations will be conducted how to block the heat to insulation material. CCS components which consist of various materials are especially the main interests, and how the temperature of the entire CCS along the location is should be investigated through these studies. With the experimental thermal properties, the steady state thermal analysis of the entire cargo system was conducted. When the LNG leaked through the insulation system with external impact, temperature distribution and thermal safety of secondary barrier, especially plywood and hull structure, was observed.