• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.2
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• pp.68-73
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• 2011

For the launch preparation of KSLV-I, gaseous nitrogen with various level of pressure and cryogenic liquid nitrogen are required. Nitrogen Supply System on launch complex has been developed to perform the production of high pressure gaseous nitrogen, the production of gaseous nitrogen with temperature of 273 ${\pm}$ 2K for protection purge of launch vehicle after loading of propellant and the supply of cryogenic liquid nitrogen for cooling of fuel (kerosene) and oxidizer (liquid oxygen). The operational instability of vaporizer mainly caused by its heat transfer characteristics which sensitively depends on the atmospheric conditions was removed by introducing parallel installation of two vaporizer and their switching operation. The developed Nitrogen Supply System carried out its function successfully in preparation of KSLV-I flight tests.

• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.2
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• pp.205-211
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• 2013

This paper studies on mechanical properties, fractures, and ultrasonic characteristics of Pure Titanium welds using ultrasonic attenuation. Ti specimen was made by using AR purge gas. When the titanium weld specimen is fractured, Tensile tests were conducted in order to observe the ultrasonic signal changes. A scanning electron microscope(SEM) was used to observe changes in failure surface and an ultrasonic normal probe with the central frequency of 4 MHz was used to obtain ultrasonic signals. As a result, the value of the mechanical properties in the weld zone was lower than that in the base zone and heat affected zone(HAZ) from Ti. Also the grain size in the weld zone was bigger than that in the weld zone and HAZ from Ti. Ultrasonic signals using a RMS method presents correlation between envelope area and the tensile strength. Consequently, the ultrasonic method could be potential tool for integrity evaluation of the Ti weld zone.

• Food Science of Animal Resources
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• v.34 no.2
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• pp.166-171
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• 2014

The aim of this study is to examine the influences of spices on the amounts and compositions of volatile compounds released from cooked beef patty. Beef patty with 0.5% of spice (nutmeg, onion, garlic, or ginger powder, w/w) was cooked by electronic pan until they reached an internal temperature of $75^{\circ}C$. A total of 46 volatile compounds (6 alcohols, 6 aldehydes, 5 hydrocarbons, 6 ketones, 9 sulfur compounds, and 14 terpenes) from cooked beef patties were detected by using purge-and-trap GC/MS. The addition of nutmeg, onion, or ginger powder significantly reduced the production of the volatile compounds via lipid oxidation in cooked beef patty when compared to those from the control. Also, the addition of nutmeg and garlic powder to beef patty generated a lot of trepans or sulfur volatile compounds, respectively. From these results, the major proportion by chemical classes such as alcohols, aldehydes, hydrocarbons, ketones, sulfur compounds, and terpenes was different depending on the spice variations. The results indicate that addition of spices to the beef patty meaningfully changes the volatile compounds released from within. Therefore, it can be concluded that spices can interact with meat aroma significantly, and thus, the character of each spice should be considered before adding to the beef patty.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.5
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• pp.469-473
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• 2009

We present high-voltage liquid-electrolyte microbatteries, inspired from the high-voltage generation mechanism of electric eels using serially connected multiple-cell arrays. In the microbatteries, we purge air into the electrolyte filled in a channel layer to isolate serially connected multiple cell arrays using three surface-tension valves (cell-front, outlet, and cell-end valves). Compared to the previous multi-cell stack or interconnection, present microbatteries provide a reduced multi-cell charging time. We have designed and characterized four different prototypes C1, C10, C20, and C40 having 1, 10, 20, and 40 cells, respectively. In the experimental study, the threshold pressures of cell-front, outlet, and cell-end valves were measured as $460{\pm}47$, $1,000{\pm}53$, and $2,800{\pm}170$ Pa, respectively. The average charging time for C40 was measured as $26.8{\pm}4.9$ seconds where the electrolyte and air flow-rates are 100 and $10{\mu}l/min$, respectively. Microbatteries showed the maximum voltage of 12 V (C40), the maximum power density of $110{\mu}W/cm^2$ (C40), and the maximum power capacity of $2.1{\mu}Ah/cm^2$ (C40). We also proposed a tapered-channel to remove the reaction gas from the cell chamber using a surface tension effect. The present microbatteries are applicable to high-voltage portable power devices.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.178-178
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• 2010

With the scaling down of ULSI(Ultra Large Scale Integration) circuit of CMOS(Complementary Metal Oxide Semiconductor)based electronic devices, the electronic devices become more faster and smaller size that are promising field of semiconductor market. However, very narrow line width has some disadvantages. For example, because of narrow line width, deposition of conformal and thin barrier is difficult. Besides, proportion of barrier width is large, thus resistance is high. Conventional PVD(Physical Vapor Deposition) thin films are not able to gain a good quality and conformal layer. Hence, in order to get over these side effects, deposition of thin layer used of ALD(Atomic Layer Deposition) is important factor. Furthermore, it is essential that copper atomic diffusion into dielectric layer such as silicon oxide and hafnium oxide. If copper line is not surrounded by diffusion barrier, it cause the leakage current and devices degradation. There are some possible methods for improving the these secondary effects. In this study, TaNx, is used of Tertiarybutylimido tris (ethylamethlamino) tantalum (TBITEMAT), was deposited on the 24nm sized trench silicon oxide/silicon bi-layer substrate with good step coverage and high quality film using plasma enhanced atomic layer deposition (PEALD). And then copper was deposited on TaNx barrier using same deposition method. The thickness of TaNx was 4~5 nm. TaNx film was deposited the condition of under $300^{\circ}C$ and copper deposition temperature was under $120^{\circ}C$, and feeding time of TaNx and copper were 5 seconds and 5 seconds, relatively. Purge time of TaNx and copper films were 10 seconds and 6 seconds, relatively. XRD, TEM, AFM, I-V measurement(for testing leakage current and stability) were used to analyze this work. With this work, thin barrier layer(4~5nm) with deposited PEALD has good step coverage and good thermal stability. So the barrier properties of PEALD TaNx film are desirable for copper interconnection.

• Journal of KIISE
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• v.43 no.10
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• pp.1124-1130
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• 2016

A controlled group is closed compared to other organizations, which hinders collection of data and accurate analysis, so that it is hard to evaluate a controlled group's power structure and predict future changes using usual analytical methods including sociological approach. Analyzing a controlled group using SNA can allow for evaluation of inner power structure by revealing the relationships between members and identifying members with central roles given limited data. In this study, in order to evaluate changes in power structure, time-sequential SNA research was conducted by analyzing eigenvector centrality, which reflects individual influence and reveals the overall power structure. The result showed an improvement in accuracy compared to other centralities that contain individual degree or closeness, and made it possible to presume structural changes such as promotion or purge of a member.

• Environmental and Resource Economics Review
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• v.13 no.3
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• pp.387-415
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• 2004

This paper is intended to valuate air quality of the Seoul Metropolitan Area using triple-bound dichotomous choice (TBDC) contingent valuation method (CVM), supplemented by open-ended (OE) questionnaires. In the OE questionnaires, some respondents would state their willingness to pay (WTP) outside the limits of the WTP interval. It implies that WTP estimates based on the customary dichotomous choice (DC) questionnaires can be biased. We argue that the TBDC-CVM refined with OE questions is more efficient, because the latter helps purge the former of corrupted data that may have been collected by the TBDC interview process.

• Journal of Animal Science and Technology
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• v.47 no.2
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• pp.277-282
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• 2005

The current study was conducted to investigate the effect of organic selenium in mushroom cultured media (MCM) on beef quality. Each five of 20 Hanwoo steers(20 - 24 month, approximately 613 kg) were assigned to four levels of the selenium content(O.l, 0.3, 0.6, 0.9 dry matter based ppm), and the feeding treatments were enforced for 12 weeks. The results showed that m. longissimus from the 0.1 ppm feeding supplementation had greatly higher intramuscular fat content than other treatments(13.1 %). In meat color, the 0.1 ppm treatment showed the lowest lightness(CIE $L^*$)(P< 0.05) and had a tendency to have lower redness(CIE $a^*$). The treatment had no noticeable effect on moisture, protein, and ash content, cooking loss, water-holding capacity and purge loss. The 0.3 ppm treatment resulted in the toughest meat(assessed by WB-shear force) with 4.54 kg / inch', while other groups showed a similar toughness ranging from 3.3 to 3.7 kg/ inchl . Sensory characteristics in juiciness and flavor intensity had a tendency of increasing as organic selenium concentration increased, but tenderness was not influenced by the contents. The result indicated that the organic selenium feeding affects meat qualities to different extent, and further study is required to examine anti-oxidant effect of selenium in vivo.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.3
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• pp.435-442
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• 2002

Phlegm is defined as the static fluid in excess in one or more parts of the body. It is not only a pathologic product but also a pathogen itself. However, as it says Phlegm is another title for the body fluid. phlegm can be physiological. In Hyungsang medicine. since the Hyungsang which an individual shows determines his or her illness. the principle to treat phlegm also varies according to the individual's Hyungsang. Thus, the author reviewed ‘Jisan’s Special Lectures for Clinicians’ and summarized the concepts and diagnostics of phlegm, and treatment and regimens by Hyungsang medicine. The concepts of phlegm : Phlegm is not only a pathologic product of disharmony of Jung(精), Ki(氣), Shin(神) and Hyul(血) but also a driving force to mature and transform these constituents. Phlegm is another designation for the Fluid. Phlegm can act as an alternative substance or buffering agent. If we describe our body as the habitat of worms. phlegm could be the inhabitant. Diagnostics of phlegm : The infraorbital areas have a dark-gray or blackish coloring. A man who is feminine or a woman who is masculine tends to develop phlegm. One of the major signs of phlegm is pain in Chungwan(中脘). The color of the skin does not change. Treatment of phlegm by Hyungsang medicine. For the Jung type(精科) and the Hyul type(血科), phlegm treatment is to supply Jung and Blood or eliminate Damp-phlegm. The man needs tonifying herbs and the woman needs herbs which promote the flow of Ki(氣). Children and the aged are. tegardless of the nature of disease, to be warmed and supplemented. For the heavy man. treatment is to supplement Ki and eliminate Damp; for the slim man. treatment is to supplement Yin(陰) and purge Heat.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.381-381
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• 2009

염료감응형 태양전지의 효율 향상을 위한 다양한 방법들 중 $TiO_2$ 나노 파우더의 표면 개질 및 페이스트의 분산성 향상을 위한 연구가 활발하게 진행되고 있다. 기존 나노 파우더의 표면 개질법으로는 액상 공정인 졸겔법이 있으나 표면 처리 공정에서의 응집현상은 아직 해결해야 할 과제 중 하나이다. 이에 본 연구에서는 진공증착방법인 ALD법을 이용하여 염료감응형 태양전지용 $TiO_2$ 나노 파우더의 $SiO_2$ 산화물 표면처리를 통한 분산특성을 파악하였다. 기존 ALD법의 경우 reactor의 온도가 $300{\sim}500^{\circ}C$ 정도의 고온에서 공정이 이루어졌지만 본 실험에서는 2차 아민계촉매(pyridine)을 사용하여 reactor의 온도를 $30^{\circ}C$정도의 저온공정에서 $SiO_2$ 산화물을 코팅을 하였다. MO source로는 액체상태의 TEOS$(Si(OC_2H_5)_4)$를, 반응가스로는 $H_2O$를 사용하였고, 불활성 기체인 Ar 가스는 purge 가스로 각각 사용 하였다. ALD 공정에 의해 표면처리 된 $TiO_2$ 나노 파우더의 분산특성은 각 공정 cycle에 따라 FESEM을 통하여 입자의 형상 및 분산성을 확인하였으며 입도 분석기를 통하여 부피의 변화 및 분산 특성을 확인하였다. 공정 cycle 이 증가함에 따라 입자간의 응집현상이 개선되는 것을 확인 할 수 있었으며, 100cycles에서 응집현상이 가장 많이 감소하는 것을 확인할 수 있었다. 또한 표면 처리된 $SiO_2$ 산화막은 XRD를 통한 결정 분석 및 EDX를 통한 정성 분석을 통하여 확인하였다.