• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.182-183
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• 2006

$CuInSe_2$ single crystal thin films was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the hot wall epitaxy (HWE) system. The temperature dependence of the energy band gap of the $CuInSe_2$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)\;=\;1.1851\;eV\;-\;(8.99\;{\times}\;10^{-4}\;eV/K)T^2/(T\;+\;153K)$. After the as-grown $CuInSe_2$ single crystal thin films was annealed in Cu-, Se-, and In-atmospheres, the origin of point defects of $CuInSe_2$ single crystal thin films has been investigated by the photoluminescence(PL) at 10 K.

• Bulletin of the Korean Chemical Society
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• 제20권9호
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• pp.1035-1039
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• 1999

Manganese-activated zincgallate (Zn1-xMnxGa2O4) phosphor as a green phosphor was readily prepared by coprecipitation in aqueous basic solution of metal salts. The obtained product converted to amorphous zincgallate even at 300℃, followed by crystallization at 1000 ℃. The pyrolyzed phosphor showed fine particle, then reduction treatment at 900 ℃ changed into homogeneous shape with slight grain growth(particle size less than 0.5 mm). The photoluminescence characteristics of the zincgallates have been investigated as a function of dopant concentrations, reducing atmospheres and temperatures. Under UV excitation the phosphors displayed the highest green emission efficiency at 504 nm when the specimen oxidized at 1000 ℃ was reduced at 900 ℃ in a mild hydrogen atmosphere (97% N2, 3% H2) with a flow rate of 100 ml/min.

• Advances in concrete construction
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• 제3권1호
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• pp.39-54
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• 2015

Relative humidity and strains within a massive concrete cylinder (${\varphi}450mm{\times}900mm$) in the drying and the re-saturating process were measured for elucidating the process of ASR surface cracking in concrete. The expansion behavior of mortars in dry atmospheres with various R.H. values and the resaturating process was revealed. Non- or less-expansive layers were formed in near-surface regions in the concrete cylinder in the drying process, but ASR expansions actively progressed in inner portions. After resaturating, R.H. values of near-surface regions rapidly increased with time, but expansions in the regions were found to be very small. However, in the middle portions, of which R.H. values were kept 80% ~ 90% R.H. in the drying process, expansion actively progressed, resulting in further development of surface cracks in the re-saturating process.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.170.2-170.2
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• 2003

The most common cause of death in fires is the inhalation of noxious gases rather than thermal injury. Carbon monoxide is well-known toxic component in fire atmospheres. However, the importance of hydrogen cyanide(HCN) as a toxic agent in the fire related fatalities(FRF) is under discussion. HCN is known to be produced in fires involving by the pyrolysis of polyacrylonitril (PAN) and other nitrogen-containing polymer. (omitted)

• Journal of Ceramic Processing Research
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• 제20권4호
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• pp.388-394
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• 2019

In this study, high-purity single-walled carbon nanotubes (SWCNTs) were prepared by removing the unreacted metal constituents and amorphous carbon impurities using a post-annealing process. Unlike conventional thermal processing techniques, this technique involved different gas atmospheres for efficient removal of impurities. A heat treatment was conducted in the presence of chlorine, oxygen, and chlorine + oxygen gases. The nanotubes demonstrated the best characteristics, when the heat treatment was conducted in the presence of a mixture of chlorine and oxygen gases. The scanning electron microscopy, transmission electron microscopy, ultraviolet absorbance, and sheet resistance measurements showed that the heat treatment process efficiently removed the unreacted metal and amorphous carbon impurities from the as-synthesized SWCNTs. The high-purity SWCNTs exhibited improved electrical conductivities. Such high-purity SWCNTs can be used in various carbon composites for improving the sensitivity of gas sensors.

• Advances in Energy Research
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• 제8권4호
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• pp.265-273
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• 2022

In this study, a product gas yield and carbon conversion were measured during the coal pyrolysis. The pyrolysis process occurred under two different atmospheres such as subcritical (45 bar, 10℃) and supercritical CO₂ condition (80 bar, 35℃). Under the same pressure (80 bar), the atmosphere temperature increased from 35℃ to 45℃ to further examine temperature effect on the pyrolysis at supercritical CO₂ condition. For all three cases, a power input supplied to heating wire placed below coal bed was controlled to make coal bed temperature constant. The phase change of CO₂ atmosphere and subsequent pyrolysis behaviors of coal bed were observed using high-resolution camcorder. The pressure and temperature in the reactor were controlled by a CO₂ pump and heater. Then, the coal bed was heated by wire heater to proceed the pyrolysis under supercritical CO₂ condition.

• International Journal of Advanced Culture Technology
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• 제11권2호
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• pp.366-374
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• 2023

Growing environmental awareness around the world has made environmental issues increasingly important in business. While most past research has focused on consumers' sustainable morals and lifestyles as the main motivations for eco-friendly consumption, few studies have examined the effect of traditional marketing programs on sustainable consumption. In this study, the author posited that delicate visual cues in store retail environments, particularly visual cues of the store interiors, affect the ways consumers evaluate the brand. The author specifically tested the effect of visual congruence, or the perceived fit between brands and visual cues in retail atmospheres, on perceived brand image and trust. The results of the online survey of 622 U.S. consumers indicated that visual congruence has a significant positive effect on consumer trust in the brand. The author also hypothesized that environmental concerns would moderate the relationships. consumers' subjective environmental concerns do not moderate the positive effect of visual congruence on trust in the brand.

• 천문학논총
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• 제8권1호
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• pp.169-177
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• 1993

Observed spectra of supernovae allow the empirical classification of supernovae into two basic categories, Type I with little or no evidence of hydrogen, and Type II with obvious evidence for hydrogen. The broad class of Type I can be subdivided depending on whether helium or silicon and other intermediate mass elements is observed. Understanding the physical processes that underlie these classifications---the progenitor evolution. the explosion mechanism, and end products---requires calculation of radiative transfer and model spectra. While most Type II occur in evolved massive stars that undergo core collapse. some may span the dividing line between degenerate and non-degenerate carbon burning and involve both core collapse and thermonuclear explosion. Type Ia are still most plausibly explained as thermonuclear explosions in carbon/oxygen white dwarfs in binary systems. Type Ib reveal helium atmospheres and are probably the result of core collapse in the helium core of a massive star that has lost its hydrogen envelope to a binary companion or to a wind. Type Ic supernovae are probably related to Type Ib but have also lost their helium envelope to reveal a mantle rich in oxygen.

• 한국결정성장학회지
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• 제15권5호
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• pp.208-215
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• 2005

골재를 제조할 때 골재의 중앙에 만들어지는 블랙코어(black core)의 형성 메커니즘을 살펴보기 위해 적점토, 탄소(carbon), 산화철$(Fe_2O_3)$이 혼합된 직경 10mm 구형골재의 조성, 소성온도, 소성시간, 소성분위기, 소성방법을 변화시키면서 각각의 비중, 흡수율, 블랙코어 면적비$(\%)$, 파괴강도, Fe 총량분석, XRF를 측정하고 비교하였다. 소량의 산화철 첨가는 골재의 물성에 큰 영향을 미치지 않는 반면 탄소는 많이 첨가될수록, 소성온도가 증가할수록 블랙코어가 더 많이 형성되었고, 블랙코어의 비율이 증가하면 그만큼 비중은 감소하고 흡수율은 증가하였다 산화분위기에서 소성시킨 골재는 껍질 (shell)과 블랙코어가 뚜렷하게 구분되는 반면 환원분위기에서 소성한 시편에서는 시편의 단면전체에 블랙코어가 형성되었고, 산화분위기와 중성분위기와는 달리 환원분위기에서 소성된 시편에서는 탄소첨가량이 증가할수록 비중이 증가했으며, 전반적인 비중은 가장 낮았다. 흡수율은 모든 분위기에서 탄소 첨가량이 증가할수록 증가했다. 소성방법을 달리하여 실험한 결과 직화소성한 시편에서는 블랙코어가 잘 형성되었고, 승온소성한 시편에 비해 비중은 작고 흡수율은 높았다. 또한 파괴강도의 측정결과를 통해 블랙코어가 형성되지 않은 골재시편의 강도가 블랙코어가 형성된 시편보다 다소 크다는 사실을 알 수 있었다. Fe총량분석결과 블랙코어에서 껍질보다 많은 Fe와 FeO가 분포하였고, 껍질에는 적색을 띠는 $Fe_2O_3$가 많이 분포되어 있었다. XRF 분석 결과를 통해 탄소는 블랙코어 형성부위에서만 존재한다는 것을 알 수 있었다.사 결과 외형은 YF04 $1.0\%$ 처리구가 3.64으로 높게 나타났으며 YM03 $0.1\%$ 처리구가 3.00으로 가장 낮았다(P>0.05). 색은 YF04 $1.0\%$ 처리구가 4.00으로 높았으며 YF04 $0.1\%$ 처리구는 2.93으로 가장 낮았다(P<0.05). 다즙성은 YF04 $1.0\%$ 처리구가 3.50으로 가장 높게 나타났으며 YM03 $0.1\%$와 YM03 $1.0\%$ 처리구가 각각 3.07로 낮았다 (P>0.05).구보다 약간 증가하였으나 큰 차이를 나타내지 않았다.다리살의 콜레스테롤 함량도 감소하는 경향을 보였으나 유의적인 차이는 없었다.적으로 작용하였다.있다.>16$\%$>0$\%$ 순으로 좋게 평가되었다. 결론적으로 감농축액의 첨가는 당과 탄닌성분을 함유함으로써 인절미의 노화를 지연시키고 저장성을 높이는데 효과가 있는 것으로 생각된다. 또한 인절미를 제조할 때 찹쌀가루에 8$\%$의 감농축액을 첨가하는 것이 감인절미의 색, 향, 단맛, 씹힘성이 적당하고 쓴맛과 떫은맛은 약하게 느끼면서 촉촉한 정도와 부드러운 정도는 강하게 느낄수 있어서 전반적인 기호도에서 가장 적절한 방법으로 사료된다.비위생 점수가 유의적으로 높은 점수를 나타내었다. 조리종사자의 위생지식 점수와 위생관리 수행수준의 상관관계를 조사한 결과, 위생지식의 기기설비위생은 위생관리 수행수준의 합계(p<0.01)에서 유의적인 상관관계(p<0.01)를 나타내었으며, 위생지식의 식중독 및 미생물은

• 한국강구조학회 논문집
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• 제16권4호통권71호
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• pp.415-423
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• 2004

옥외 강구조물의 중요 소재인 무도장 내후성강의 장기 내식성을 평가하기 위해 우선 9년 이상 산업대기와 전원대기에 폭로된 본 강판 및 비교재 일반강판 시편의 천향면에 대해 중성의 인공우수에 침적시켜 전기화학적 부식전위, 임피던스 및 동전위 양분극 곡선으로 측정 및 그 결과를 고찰하였다. 산업대기 및 전원대기에 천향면으로 폭로된 내후성강 표면에는 부동태적인 안정화 녹층이 발달하였으며, 산업대기 폭로 표면의 인공우수에서의 부식속도는 $3{{\mu}m}/y$로 측정되어 우수한 내후내식 녹층으로 덮혀 있었다. 지속적으로 인공우수에 침적시키면 모든 시편 녹층은 점진적으로 열화되어 모재 철분의 양극산화용해 율속의 부식으로 진전됨을 나타내었다. 내후성 합금성분은 이런 부식의 진전을 지연시키고 있었다. 장기 내식성을 잘 평가하기 위해서는 9년보다 훨씬 장기간 대기폭로된 강재표면과 해당 대기 응축수 모사 수용액을 이용한 전기화학적 측정이 필요하다. 특히 본 측정방법들은 강재 표면의 원하는 부위와 폭로시간대에 거의 비파괴적으로 부식상황과 녹층의 상태와 정량적인 부식속도를 직접 바로 측정할 수 있게 하므로 강재를 사용한 교량, 탑, 건축물 등의 강구조물의 표면에 전기화학적 cell을 구성하고 이동측정기를 사용하면 강구조물의 내후 내식성을 현장즉시 측정 및 평가를 효과적으로 가능하게 할 수 있다.