• 한국진공학회지
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• 제8권3A호
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• pp.201-206
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• 1999

Transparent and conduction tin oxide films have been deposited on glass substrates employing the low pressure chemical vapor deposition technique. Tetramethyltin, 1, 1, 1, 2-tetrafluoroethane, and pure oxygen or ozone-containing oxygen were used as the precursor, dopant and oxidant, respectively. In order to examine the role of ozone in the low pressure chemical vapor deposition of tin oxide films, deposition rate, and electrical and optical properties of tin oxide films deposited using ozone-containing oxygen were compared with those using pure oxygen. Tetramethyltin and 1, 1, 1, 2-tetrafluoroethane were chemically activated by thermally initiated decomposition of ozone. Using ozone-containing oxygen under otherwise identical deposition conditions, we succeeded in preparing tin oxide films f better quality at higher deposition rate.

• Applied Microscopy
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• 제48권4호
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• pp.122-125
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• 2018

The focused ion beam (FIB) method is widely used to prepare specimens for observation by transmission electron microscopy (TEM), which offers a wide variety of imaging and analytical techniques. TEM has played a significant role in material investigation. However, the FIB method induces amorphization due to bombardment with the high-energy gallium ($Ga^+$) ion beam. To solve this problem, electron beam induced deposition (EBID) is used to form a protective layer to prevent damage to the specimen surface. In this study, we introduce an optimized TEM specimen preparation procedure by comparing the EBID of carbon and tungsten as protective layers in FIB. The selection of appropriate EBID conditions for preparing specimens for TEM analysis is described in detail.

• Journal of the Korean Wood Science and Technology
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• 제47권2호
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• pp.178-188
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• 2019

Licorice, which has an extensive history of use as an herbal medicine, has been suggested to have oral health benefits. However, to date, no systematic study has been conducted on the preparation method of licorice extracts for oral health. In this study, licorice extracts prepared using water and ethanol were investigated for its ability to inhibit the biofilm formation of Streptococcus mutans. The licorice extract prepared with around 60% ethanol effectively inhibited the biofilm formation of S. mutans. Licorice extracted with 50% ethanol almost completely inhibited the biofilm formation at 1.5 g/L of licorice extract. This inhibitory activity was confirmed in a microplate assay and a flow cell system. Glycyrrhetic acid was extracted from licorice effectively with 60% ethanol concentration. The strong inhibitory activity of glycyrrhetic acid and the synergistic inhibition with glycyrrhizin on biofilm formation were suggested as major reasons for a concentration-specific extraction. These results suggest that licorice extract prepared using around 60% ethanol effectively inhibits the biofilm formation of S. mutans.

• 대한금속재료학회지
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• 제48권3호
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• pp.268-275
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• 2010

A new approach is described for preparing AlN thin films containing various amounts of Co content by using a two-facing targets type sputtering (TFTS) system. The deposited films were annealed isothermally at different temperatures and their microstructure, magnetic properties and resistivity were investigated. A small saturation magnetization ($4{\pi}Ms=0.52{\sim}0.85kG$) was observed irrespective of Co content in the asdeposited films. It was found that annealing conditions can control physical properties as well as the microstructure of the films. A high saturation magnetization (3.7 kG) and resistivity of $2200{\mu}{\Omega}-cm$ was obtained for AlN films containing 25 at.% Co.

• Journal of Ecology and Environment
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• 제47권2호
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• pp.27-34
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• 2023

Background: The understanding of ecosystem services can be quantified and qualitative to assess the impacts of changes in the ecosystem to support human well-being. In the Democratic People's Republic of Korea, sustainable use of ecosystem services has attracted the interest of a range of decision-makers. However, although there is a concern for biodiversity, natural ecosystem, and their services, linking ecosystems with conservation planning remains challenging. Results: This study assessed the first qualitative ecosystem services provided by the Mundok wetland with decision makers of the West/Yellow Sea region. Furthermore, this study applied the Rapid Assessment Wetland Ecosystem method to support natural resources management, improving living conditions. We identified that cultural and supporting services index are highly provided, but preparing a plan to increase the provisioning and regulating services in Mundok wetland is necessary. Conclusions: The assessment results can provide helpful information for ecosystem services assessment, habitat conservation, conservation planning, and decision-making at local level.

• 대한방사선기술학회지:방사선기술과학
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• 제29권3호
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• pp.141-145
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• 2006

염화알칼리토금속화합물에 Eu 이온을 첨가하여 $MCl_2:Eu^{2+}$(M = Ca, Sr, Ba) 형광체를 제조하고, 제조된 형광체의 광발광(photoluminescene) 및 광자극발광(photostimulated luminescence ; PSL) 특성을 조사하였다. $MCl_2:Eu^{2+}$(M = Ca, Sr, Ba)형광체의 광발광 및 광자극발광 파장은 주 모체의 양이온의 종류에 따라 조금씩 이동하였다. $CaCl_2:Eu^{2+}$ 형광체의 최적 제조조건은 $Eu^{2+}$ 이온의 농도가 0.5 mol%, 소결온도와 시간은 각각 $745^{\circ}C$, 45분이었으며, 이때 발광파장범위는 $365{\sim}388\;nm$, 피이크파장은 370 및 380 nm이었다. $BaCl_2:Eu^{2+}$ 형광체의 최적 제조조건은 $Eu^{2+}$ 이온의 농도가 0.5 mol%, 소결온도와 시간은 각각 $905^{\circ}C$, 45분이었으며, 이때 발광파장범위는 $370{\sim}460\;nm$, 피이크파장은 398 nm이었다. $SrCl_2:Eu^{2+}$ 형광체의 최적조건은 $Eu^{2+}$ 이온의 농도가 0.5 mol%, 소결온도와 시간은 각각 $840^{\circ}C$, 45분이었으며, 발광파장영역은 $380{\sim}440\;nm$, 피이크파장은 407 nm이었다. $MCl_2:Eu^{2+}$(0.5 mol%)(M = Ba, Sr) 형광체는 약 $0.25{\sim}200\;mGy$까지 선량 범위에서 선형성을 나타내었으며, 상온에서 $SrCl_2:Eu^{2+}$ (0.5 mol%) 및 $BaCl_2:Eu^{2+}$ (0.5mol%) 형광체의 광자극발광 강도는 상온에서 120분간 각각 60%, 40% 감쇠하였다.

• 가족자원경영과 정책
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• 제16권2호
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• pp.123-143
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• 2012

This study, based on a health belief model, examines how baby boomers perceive health and how they are financially preparing for future medical expenses. In addition, the study analyzes which factors influence baby boomers' preparation behaviors for future medical expenses and their perceived sufficiency of the preparation for medical expenses. Through such activities, this study examines baby boomers' current preparation status for future medical expenses, and based on this outcome, will turn the attention of individuals and society toward becoming more concerned with health and increasing health expectancy. For this study, an online survey was conducted targeted at men and women who were born between 1955 and 1963 and live nationwide, and its resultant data were collected. After conducting a 15-day survey in November 2011, a total of 418 questionnaire responses were used for the final analysis. The major findings of this study and their implications are as follows: First, baby boomers' health beliefs and their perceptions of health identified by subjective health conditions were very positive. Second, while there were some partial differences in the influencing factors, health beliefs and perceived health influenced the sufficiency of future medical expenses in the three groups, which were segmented according to how they prepare for future medical expenses-insurance-based, pension-based, and insufficiently prepared groups. Third, the baby boomers selected the national health insurance as the primary means of preparing for post-retirement medical expenses, and backed it up with private health insurance or the national pension. In addition, when baby boomers' perceived sufficiency of future medical expenses were examined, 57.6% of the respondents expressed that their old-age medical expenses were not sufficient. Fourth, in terms of baby boomers' preparation behaviors for future medical expenses, it was revealed that as one recognizes old-age health more seriously, he/she has a higher chance of using insurance and lower chance of using a pension to prepare for medical expenses. Fifth, regarding baby boomers' sufficiency of preparations for future medical expenses, economic factors such as total assets, the sufficiency of retirement assets, and the number of insurance policies, as well as health perceptions, including health beliefs and subjective health conditions, were important influencing factors.

• 한국환경농학회지
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• 제24권2호
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• pp.164-168
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• 2005

인삼의 휘발성 성분 분석 시 SFSI를 이용한 분석법의 최적화를 일하여 실험을 수행하였다. 최적화를 위하여 세 가지 시료조제방법인 생체시료, oven건조와 동결건조를 검토하였고, GC injector 온도는 100, 150, 200, 250, $300^{\circ}C$에서의 휘발성분 분석효율을 검토하였으며, 모세관에서 시료의 기화 시간인 preheating time은 3, 5, 7, 10, 15 min의 조건에서 검토한 결과, 시료 조제방법은 생체시료를 그대로 사용 시, GC injector 온도는 $250^{\circ}C$일 때 preheating time은 10min일 때 가장 분석효율이 높았다. 휘발성분 분석을 위해 사용된 인삼은 금산에서 재배한 6년근 삼으로 수삼, 백삼, 홍삼을 사용하였으며, SFSI가 장착된 CC/MS에 의해 휘발성분을 분석, 동정하였다. 분석결과 수삼에서는 33종, 백삼에서는 36종, 홍삼에서는 38종의 휘발성분이 분석되어져 SFSI에 의한 분석법이 인삼의 휘발성분을 분석, 동정하는 방법으로 이용될 수 있음을 보여주고 있다.

• 한국식품영양학회지
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• 제26권4호
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• pp.985-989
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• 2013

본 연구에서는 수문사설 에 수록된 토란병의 제조방법을 확립하기 위하여 토란의 가열 시간 및 고명에 따라 토란병을 제조하고, 품질특성을 비교 분석하였다. 가열 시간에 따른 수분, 조단백질, 조지방 및 조회분 함량은 각각 83.42~84.61%, 1.25~1.31%, 0.08~0.11%, 0.62~0.81% 범위로 조지방은 유의적인 차이가 없었으며, 조회분은 가열처리로 인해 유의적으로 감소하였다. 토란의 주요 유리당은 fructose, glucose 및 sucrose가 검출되었고, 가열 시간에 따라 각각 0.17~0.33%, 0.16~0.29% 및 0.26~0.38% 범위로 15분 가열처리 때까지 유의적으로 감소하였다. 경도 역시 가열 시간이 늘어날수록 2.75 kg에서 0.14 kg까지 감소하였다. 가열 시간에 따른 관능특성을 평가한 결과, 향과 맛은 각 처리구간 유의적인 차이를 보이지 않았고, 질감과 전반적인 기호도는 5분 처리구가 다른 처리구에 비해 유의적으로 낮게 평가되었으며, 10분 처리 이후에는 큰 차이를 보이지 않았다. 이상의 결과, 토란병의 제조 시 가열 시간은 10분이 바람직할 것으로 판단된다. 잣고물, 콩고물, 검은 깨고물 및 밤고물 등 고명 종류에 따른 토란병의 관능특성을 평가한 결과, 색, 향, 질감, 맛 및 전반적인 기호도는 각각 5.20~7.50, 5.40~7.70, 6.10~7.00, 6.10~7.20 및 6.20~7.60 범위로 평가되었고, 콩고물을 묻힌 토란병이 모든 항목에서 가장 높게 평가되었다.

• 한국응용과학기술학회지
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• 제28권1호
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• pp.85-94
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• 2011

Expanded graphites were used as anode materials of high power Li-ion secondary battery. The expanded graphite was prepared by mixing the graphite with $HClO_4$ as a intercalation agents and $KMnO_4$ as a oxidizing agents. The physical and electrochemical properties of prepared expanded graphites through the variation of process variables such as contents of intercalation agent and oxidizing agent, and heat treatment temperature were analyzed for determination of optimal conditions as the anode of high power Li-ion secondary battery. After examing the electrochemical properties of expanded graphites at the different preparing conditions, the optimal conditions of expanded graphite were selected as 8 wt.% of oxidizing agent, 400 g of intercalation agent for 20 g of natural graphite, and heat treatment at $1000^{\circ}C$. The sample showed the improved charge/discharge characteristics such as 432 mAh/g of initial reversible capacity, 88% of discharge rate capability at 10 C-rate, and 24 mAh/g of charge capacity at 10 C-rate. However, the expanded graphite had the problems of potential plateaus like natural graphite and lower initial efficiency than the natural graphite.