• 한국건설순환자원학회논문집
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• 제2권4호
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• pp.328-334
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• 2014

본 연구는 태양광 소재인 폴리실리콘 제조시 부산되는 슬러지를 시멘트 클링커의 원료로서 사용 가능성에 대해 검토하였다. 시멘트 클링커를 제조 할 때, 폴리실리콘의 염소 성분이 소성과정에서 광화제로 작용하여 f-CaO 생성량을 낮추고, 시멘트 클링커 광물 중 $C_3S$ 생성량을 증가시킨 것으로 평가되었다. 또한 제조한 시멘트의 물리적 특성을 측정하였다. 제조 시멘트는 폴리실리콘 슬러지 함유량이 증가할수록 응결 시간을 단축시켰다. 이러한 결과는 염소 성분이 수화촉진제로써 작용해서 $C_3S$의 수화에 의해서 생성된 수산화칼슘의 용해를 촉진하기 때문이다. 또한 이러한 이유로 재령 1일에서의 모르타르 압축강도는 폴리실리콘 슬러지 함유량이 많을수록 컸다. 재령 3, 7, 28일 압축강도는 폴리실리콘 슬러지 첨가량 5wt%까지 증진되는 경향을 나타냈다. 이러한 이유는 클링커 제조 시 염소 성분이 $C_3S$ 광물 생성량을 증가시킴으로 3일 이후 압축강도를 증진시킨 것이다.

• Toxicological Research
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• 제33권1호
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• pp.43-48
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• 2017

With ultraviolet and visible light exposure, some pharmaceutical substances applied systemically or topically may cause phototoxic skin irritation. The major factor in phototoxicity is the generation of reactive oxygen species (ROS) such as singlet oxygen and superoxide anion that cause oxidative damage to DNA, lipids and proteins. Thus, measuring the generation of ROS can predict the phototoxic potential of a given substance indirectly. For this reason, a standard ROS assay (ROS assay) was developed and validated and provides an alternative method for phototoxicity evaluation. However, negative substances are over-predicted by the assay. Except for ultraviolet A (UVA), other UV ranges are not a major factor in causing phototoxicity and may lead to incorrect labeling of some non-phototoxic substances as being phototoxic in the ROS assay when using a solar simulator. A UVA stimulator is also widely used to evaluate phototoxicity in various test substances. Consequently, we identified the applicability of a UVA simulator to the ROS assay for photoreactivity. In this study, we tested 60 pharmaceutical substances including 50 phototoxins and 10 non-phototoxins to predict their phototoxic potential via the ROS assay with a UVA simulator. Following the ROS protocol, all test substances were dissolved in dimethyl sulfoxide or sodium phosphate buffer. The final concentration of the test solutions in the reaction mixture was 20 to $200{\mu}M$. The exposure was with $2.0{\sim}2.2mW/cm^2$ irradiance and optimization for a relevant dose of UVA was performed. The generation of ROS was compared before and after UVA exposure and was measured by a microplate spectrophotometer. Sensitivity and specificity values were 85.7% and 100.0% respectively, and the accuracy was 88.1%. From this analysis, the ROS assay with a UVA simulator is suitable for testing the photoreactivity and estimating the phototoxic potential of various test pharmaceutical substances.

• 대한인간공학회지
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• 제36권1호
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• pp.23-36
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• 2017

Objective: This paper presents a study to evaluate the WBGT index for assessing the effects of a wide range of outdoor weather conditions on human responses. Background: The Wet Bulb Globe Temperature (WBGT) index was firstly developed for the assessment of hot outdoor conditions. It is a recognised index that is used world-wide. It may be useful over a range of outdoor conditions and not just for hot climates. Method: Four group experiments, involving people performing a light stepping activity, were conducted to determine human responses to outside conditions in the U.K. They were conducted in September 2007 (autumn), December 2007 (winter), March 2008 (spring) and June 2008 (summer). Environmental measurements included WBGT, air temperature, radiant temperature (including solar load), humidity and wind speed all measured at 1.2m above the ground, as well as weather data measured by a standard weather station at 3m to 4m above the ground. Participants' physiological and subjective responses were measured. When the overall results of the four seasons are considered, WBGT provided a strong prediction of physiological responses as well as subjective responses if aural temperature, heart rate and sweat production were measured. Results: WBGT is appropriate to predict thermal strain on a large group of ordinary people in moderate conditions. Consideration should be given to include the WBGT index in warning systems for a wide range of weather conditions. However, the WBGT overestimated physiological responses of subjects. In addition, tenfold Borg's RPE was significantly different with heart rate measured for the four conditions except autumn (p<0.05). Physiological and subjective responses over 60 minutes consistently showed a similar tendency in the relationships with the $WBGT_{head}$ and $WBGT_{abdomen}$. Conclusion: It was found that either $WBGT_{head}$ or $WBGT_{abdomen}$ could be measured if a measurement should be conducted at only one height. The relationship between the WBGT values and weather station data was also investigated. There was a significant relationship between WBGT values at the position of a person and weather station data. For UK daytime weather conditions ranging from an average air temperature of $6^{\circ}C$ to $21^{\circ}C$ with mean radiant temperatures of up to $57^{\circ}C$, the WBGT index could be used as a simple thermal index to indicate the effects of weather on people. Application: The result of evaluation of WBGT might help to develop the smart clothing for workers in industrial sites and improve the work environment in terms of considering workers' wellness.

• Journal of Electrochemical Science and Technology
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• 제10권4호
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• pp.424-432
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• 2019

Planar BiVO₄ and 3 wt% Mo-doped BiVO₄ (abbreviated as Mo:BiVO₄) film were prepared by the facile spin-coating method on fluorine doped SnO₂(FTO) substrate in the same precursor solution including the Mo precursor in Mo:BiVO₄ film. After annealing at a high temperature of 450℃ for 30 min to improve crystallinity, the films exhibited the monoclinic crystalline phase and nanoporous architecture. Both films showed no remarkably discrepancy in crystalline or morphological properties. To investigate the effect of surface passivation exploring the Al₂O₃ layer, the ultra-thin Al₂O₃ layer with a thickness of approximately 2 nm was deposited on BiVO₄ film using the atomic layer deposition (ALD) method. No distinct morphological modification was observed for all prepared BiVO₄ and Mo:BiVO₄ films. Only slightly reduced nanopores were observed. Although both samples showed some reduction of light absorption in the visible wavelength after coating of Al₂O₃ layer, the Al₂O₃ coated BiVO₄ (Al₂O₃/BiVO₄) film exhibited enhanced photoelectrochemical performance in 0.5 M Na₂SO₄ solution (pH 6.5), having higher photocurrent density (0.91 mA/㎠ at 1.23 V vs. reversible hydrogen electrode (RHE), briefly abbreviated as V_RHE) than BiVO₄ film (0.12 mA/㎠ at 1.23 V_RHE). Moreover, Al₂O₃ coating on the Mo:BiVO₄ film exhibited more enhanced photocurrent density (1.5 mA/㎠ at 1.23 V_RHE) than the Mo:BiVO₄ film (0.86 mA/㎠ at 1.23 V_RHE). To examine the reasons, capacitance measurement and Mott-Schottky analysis were conducted, revealing that the significant degradation of capacitance value was observed in both BiVO₄ film and Al₂O₃/Mo:BiVO₄ film, probably due to degraded capacitance by surface passivation. Furthermore, the flat-band potential (V_FB) was negatively shifted to about 200 mV while the electronic conductivities were enhanced by Al₂O₃ coating in both samples, contributing to the advancement of PEC performance by ultra-thin Al₂O₃ layer.

• 한국환경농학회지
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• 제8권1호
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• pp.30-36
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• 1989

벼 생육(生育)에 기온(氣溫)과 더불어 밀접(密接)한 영향(影響)을 주는 논의 수온(水溫) 환경(環境)의 생육시기별(生育時期別) 변화(變化)를 대기(大氣)의 온도(溫度), 습도(濕度)) 일사량(日射量)과 군락(群落)의 엽면적지수(葉面積指數)로써 추정(推定)하고자 1984년(年)에 수원(水原)과 진부(珍富)에서 측정조사(測定調査)하여 분석(分析)한 후 그 추정(推定) 수온(水溫)을 실측치(實測値)와 비교검토(比較檢討)한 결과(結果)를 요약(要約)하면 등음과 같다. 1. 벼 생육초기(生育初期)의 수온(水溫)은 대기기온(大氣氣溫)보다 최고(最高)${\cdot}$최저온도(最低溫度)가 모두 $1{\sim}2^{\circ}C$ 정도(程度)높았다. 2. 수면(水面)에 도달(到達)되는 순복사량(純輻射量)은 엽면적지수(葉面積指數)의 지수함수(指數函數)로 표현(表現)된다. 3. 벼의 엽면적지수(葉面積指數)가 $3{\sim}4$이상(以上)이 되면 수면(水面)에 도달(到達)되는 광량(光量)의 감쇠(減衰)로 논의 수온(水溫)은 대기기온(大氣氣溫)보다 낮아졌다. 4. 평야지(平野地)인 수원지방(水原地方)의 보통논에서는 조합법(組合法)을 이용(利用)한 추정수온(推定水溫)은 실측치(實測値)와 비슷한 경향(傾向)을 나타내어 대기기상(大氣氣象)에 의(依)한 논의 수온추정(水溫推定)이 가능(可能)한 것으로 판단(判斷)되었다. 그러나 산간고랭지(山間高冷地)인 진부(珍富)의 사질답(砂質畓)에서는 이 조합법(組合法)을 이용(利用)한 수온예측모형(水溫豫測模型)은 적용(適用)이 불가능(不可能)하였다.

• Journal of Information Display
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• 제12권3호
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• pp.145-152
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• 2011

Since the discovery of fullerenes as a class of nanostructure compounds, many potential applications have been suggested for their unusual structures and properties. The isolated pentagon rule (IPR) states that all pentagonal carbon rings are isolated in the most stable fullerene. Fullerenes $C_n$ are a class of spherical carbon allotrope group with unique properties. Electron transfer between fullerenes and other molecules is thought to involve the transfer of electrons between the molecules surrounding the fullerene cage. One class of electron transfer molecules is the methanofullerene derivatives ([6,6]-phenyl $C_{61}$-butyric acid methyl ester (PCBM), 4-(2-ethylhexyloxy)-[6,6]-phenyl $C_{61}$-butyric acid methyl ester (p-EHO-PCBM), and 4-(2-ethylhexyloxy)-[6,6]-phenyl $C_{61}$-butyric acid (p-EHO-PCBA), 10-12). It has been determined that $C_{60}$ does not obey IPR. Supramolecular complexes 1-9 and 10-12 are shown to possess a previously unreported host.guest interaction for electron transfer processes. The unsaturated, cis-geometry, thiocrown ethers, (1-9) (described as [X-UT-Y], where X and Y indicate the numbers of carbon and sulfur atoms, respectively), are a group of crown ethers that display interesting physiochemical properties in the light of their conformational restriction compared with a corresponding saturated system, as well as the sizes of their cavities. Topological indices have been successfully used to construct mathematical methods that relate structural data to various chemical and physical properties. To establish a good relationship between the structures of 1-9 with 10-12, a new index is introduced, ${\mu}_{cs}$. This index is the ratio of the sum of the number of carbon atoms ($n_c$) and the number of sulfur atoms ($n_s$) to the product of these two numbers for 1-9. In this study, the relationships between this index and oxidation potential ($^{ox}E_1$) of 1-9, as well as the first to third free energies of electron transfer (${\Delta}G_{et(n)}$, for n = 1-3, which is given by the Rehm-Weller equation) between 1-9 and PCBM, p-EHO-PCBM, and p-EHO-PCBA (10-12) as [X-UT-Y]@R(where R is the adduct PCBM, p-EHO-PCBM, and p-EHO-PCBA group) (13-15) supramolecular complexes are presented and investigated.

• 한국정밀공학회지
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• 제28권7호
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• pp.777-782
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• 2011

Micro features on the surface are well-known to have significant effects on optical or mechanical properties such as the optical interference, reflectance at the surface, contact angle, interfacial friction, etc. These surface micro features are increasingly employed to enhance the functionality of the applications in various application areas such as optical components for LCD or solar panel. Diverse surface features have been proposed and some of them are showing excellent efficiency or functionality, especially in optical applications. Most applications employing the micro features need manufacturing process for mass production and the injection molding and roll-to-roll forming, which are typical processes for mass production adopting polymeric materials, may be also preferred for micro patterned plastic product. Since the functionality or efficiency of the surface structures generally depends on the shape and the size of the structure itself or the array of the structures on the surface, it would be very important to replicate the features very precisely as being designed during the molding the micro pattern applications. In this paper, a series of research activities is introduced for roll-to-roll forming of micro patterned film including filling of patterns with UV curable resin, demolding of surface structures from the roll tool, control of surface energy and cure shrinkage of resin and dispose time and intensity of the UV light for curing of UV curable resin.

• 산학경영연구
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• 제22권2호
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• pp.157-179
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• 2009

이 연구는 2009년 대한민국의 저탄소 녹색시범도시로 선정된 강릉시의 녹색성장정책 사업의 사례를 조사하여 도시성장정책의 생태사업, 문화사업, 신재생에너지사업, 녹색교통사업 등 4개 부문에서 다음과 같은 시사점을 확인할 수 있었다. 첫째, 강릉시의 생태적 복원사업으로 위대한 친환경 생태복원사업은 경포해안의 불량숙박업소 철거와 이 구역에 해안송림을 재생시킨 사업이다. 둘째, 강릉시의 세계적인 문화자원은 녹색기술과 환경보전 중심의 녹색성장 정책에 대하여 문화적 다양성을 자각시키는 동인으로 작용하고 있다는 것을 확인할 수 있었다. 셋째, 강릉시는 해안을 연접하고 있고 해양이미지가 강하므로 향후 해양에너지로서 조력, 풍력, 심층수 등 다양한 사업접근이 가능하다. 넷째, 녹색교통사업으로 친환경 전력 활용, 그린카 이용 등의 사업이 추진 및 예정되어 있다. 결론적으로 강릉시의 녹색성장정책은 EcoCulture와 매우 부합하고 있다는 것을 확인할 수 있었다. 강릉시의 대다수 정책중 생태사업과 문화사업이 복합적으로 추진되고 있다는 것을 사례를 통하여 확인할 수 있었다. 이것은 강릉시와 유사한 전국의 중소도시들이 지향해야 할 저탄소 녹색도시 정책이 생태와 문화가 결합하여 시도해야 한다는 것을 의미한다. 그래서 각 도시정부는 생태적 지속성, 문화적 다양성, 경제적 유효성을 확보하도록 매진해야만 할 것이다.

• 한국결정성장학회지
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• 제12권4호
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• pp.202-209
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• 2002

$CuInSe_2$ 단결정 박막은 수평 전기로에서 합성한 다결정을 증발원으로 하여, hot wall epitaxy(HWE) 방법으로 증발원과 기판(반절연-GaAs(100))의 온도를 각각 $620^{\circ}C$, $410^{\circ}C$로 고정하여 단결정 박막을 성장하였다. 단결정 박막의 결정성은 광발광과 이중결정 X-선 요동곡선(DCRC)으로 연구하였다. $CuInSe_2$ 단결정 박막의 운반자 농도와 이동도는 van der Pauw 방법으로 측정되었다. 또한 $CuInSe_2$ 단결정 박막의 C축에 수직하게 빛을 쬐었을 때 측정되여진 단파장대의 광전류 봉우리 갈라짐으로부터 결정장 갈라짐 $\Delta$Cr과 스핀 궤도 갈라짐 $\Delta$So(spin orbit splitting) 값을 구하였다. 광발광 측정으로부터 고품질의 결정에서 볼 수 있는 free exciton($E_x$)와 매우 강한 세기의 중성 받게 bound exciton($A^{\circ}$, X) 피크가 관찰되었다. 이때 중성 받게 bound exciton의 반치폭과 결합 에너지는 각각 7meV와 5.9meV였다. 또한 Haynes nile에 의해 구한 불순물의 활성화 에너지는 59meV였다.

• 생물환경조절학회지
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• 제19권1호
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• pp.6-11
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• 2010

시설 내 PPFD는 오전에는 남북동이, 오후에는 동서동이 높았다. 일평균 PPFD는 동서동이 높았는데, 이는 태양광의 입사각이 작아질 때 동서동의 수광면적이 증가되기 때문인 것으로 조사되었다. 고랑위 60cm 높이의 PPFD는 전 고랑에서 남북동이 동서동보다 높았으나 수량과는 관련이 없었다. 평균 기온은 동서동이 높았으나 2월중순 이후로는 태양고도가 높아짐에 따라 차이가 없었다. 지온은 동서동이 다소 높았고 이랑 간에 차이가 없었다. 과실수량은 동서동이 8% 많았는데, 이는 남쪽이랑의 과실이 수확기가 빨라서 초기수량이 많았기 때문이다. 동계 단동형 비닐하우스를 이용한 토마토 촉성재배는 반촉성재배와는 달리, 동서동 시설을 이용하는 것이 유리하였다.