• 한국산업보건학회지
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• 제5권2호
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• pp.172-183
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• 1995

The airborne concentrations of the welding fumes produced during $CO_2$ arcwelding process at shipbuilding, shiprepairing, container manufacturing and car accessary manufacturing industry were investigated. The effects how much reduced the welding fume were checked when the portable fan was used. The results were as follows; 1.The geometric mean of welding fume concentration in shipbuilding factory was $10.05mg/m^3$. This exposure concentration was higher than other 3 manufacturing industries at 95% confidence level. 2. The sampling filters for welding fume could be digested with acid within 1 hour by microwave oven. The recoveries for investigated metal elements were all over 95%. 3. The optimal wavelength could be selected for the simultaneous analysis of 8 metal elements by ICP(Inductively Coupled Plasma). 4. Noxious gases($O_1,NO_2$) produced during $CO_1$ gas arc welding process were detected that the concentration of ozone($O_1$) was less than 0.01 ppm and that of nitrogen dioxide($NO_2$) was 0.01-0.03 ppm. 5. The geometric mean of welding fume particle diameter was $1.26{\mu}m$ and geometric standard deviation was 1.51 for the counts when particle an analyzer(ELZONE) had been used. 6. When the portable fan had been used,the reduced percent of total welding fume for workers was about 47.8% when portable fan was applied to blow and 71.7% when to exhaust.

• 생약학회지
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• 제37권4호
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• pp.278-282
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• 2006

In this study, we analyzed and quantified the contents of magnolol (1), honokiol (2), and obovatol (3) in the leaves of Magnolia species by HPLC. HPLC methods were developed and validated by ICH guide lines comparing the linearity, intraday precision, inter-day precision. The optimal conditions were as follows; wavelength: 288 nm, column: Zorbax Eclipse XDBC18 $(2.1\times150\;mm,\;5{\mu}m)$, mobile phase: Acetonitril - 0.1 % $H_3PO_4$ (45:55, v/v) buffer, flow rate: 0.5 ml/min. The contents of magnolol, honokiol and obovatol were 1.08%, 2.37%, and 0.57% in the leaves of M. officinalis, 0.50%, 0.03%, and 1.54% in the leaves of M. biloba, 0.37%, 0.03%, and 0.76% in the leaves of M. obovata. The contents of effective ingredients in the leaves of M. officinalis and M biloba were higher than that of M. obovata. Especially, the content of obovatol in the leaves of M. biloba was remarkably high. This result showed that the shapes of leaves have a certain relationship with the content of obovatol.

• Natural Product Sciences
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• 제21권2호
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• pp.104-110
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• 2015

The activities on the inhibition of NO on LPS-induced RAW 264.7 macrophages were investigated in this work. A simple and sensitive method has been developed and validated for fingerprinting analysis of leaves of Acanthopanax gracilistylus W.W. Smith (AGS). The cytotoxicity and inhibition of NO on LPS-induced RAW 264.7 cells of the extract and triterpenoids were determined. Optimal conditions of HPLC analysis were established as follows. The separation was performed with an ODS-C₁₈ column at $30^{\circ}C$, the detected wavelength was 210 nm, the flow rate was 1 mL/min, and the mobile phase consisted of acetonitrile (0.05% phosphoric acid)-0.05% phosphoric acid solution with gradient elution. Our results showed that impressic acid and acankoreaogenin was more effective on the inhibition of NO than the methanol extract and other compounds. There were seventeen peaks coexisted with similarities above 0.95 and nine lupane-triterpenoids including acankoreaogenin and impressic acid detected and identified. The result of anti-inflammatory activities provides a potential explanation for the use of AGS leaves as a herbal medicine in the treatment of inflammatory diseases. Our results also show that acankoreanogenin and impressic acid may be potentially useful in developing new anti-inflammatory agents. In addition, the fingerprint chromatography clearly illustrated and confirmed the material basis for the anti-inflammatory activities of this plant.

• 한국음향학회지
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• 제18권1호
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• pp.10-15
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• 1999

본 연구는 35° Y-X Quartz 기판에 낮은 형상 요소를 갖는 Code Division Multiple Access(CDMA)방식 기지국용 Intermediate Frequency (IF)단 통과대역 필터를 설계하고 제작하는 방법에 대해 연구하였다. 이 기판 위에 임펄스 모델링을 이용하여 낮은 형상 요소를 갖는 표면 탄성파 필터를 제작하기 위해 입력단에는 Apodization weighted형의 빗살무늬 변환기, 출력단에는 Withdrawal weighted형의 빗살무늬 변환기로 구성하였다. 그리고 입출력 IDT의 개수는 리플의 영향을 최소화하기 위해 Kaiser-Bessel 창함수를 이용하였으며, 각각 2200쌍과 1000쌍으로 하였다. IDT 전극의 폭은 3.6㎛, 간격은 3.5㎛였으며 두께는 파장과의 비를 고려해 6000Å으로 할 때 최적의 결과를 얻을 수 있었으며, 구경은 임피던스 정합을 위해 2mm로 하였다. 제작된 SAW필터는 중심 주파수 115.2MHz, 통과대역 폭은 1.27MHz이상, 형상 요소는 1.3이하, 삽입손실 -l5dB 및 저지대역 -45dB이하인 특성을 얻을 수 있었다.

• 한국콘텐츠학회논문지
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• 제11권4호
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• pp.57-66
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• 2011

현재 디지털 카메라가 적외선 카메라로 예술과 법과학 분야에서 활용 되고 있다. 하지만 디지털 카메라는 촬영이나 광원과 같은 기본적인 이론에 대한 이해가 필요하다는 단점이 있기 때문에 본 논문에서는 적외선 평판 스캐너를 개발하였다. 적외선 카메라의 개발 과정은 다음과 같다. 첫 번째, 가시광선용 형광램프를 적외선 LED로 교체하였다. 두 번째, 완전한 적외선 평판 스캐너를 위하여 유리판 위해 810nm이상 투과가 가능한 롱 패스 필터를 장착하였다. 적외선 디지털 카메라는 촬영을 할 경우 매번 적외선 광원을 조사(Irradiation)해 주어야 하는 번거로움과 가시광선 과 다른 적외선의 특성으로 인하여 생기는 초점문제 그리고 직접 컴퓨터로 옮겨야 하는 작업들이 여전히 존재한다. 이러한 문제를 개선하기 위해 본 논문에서 개발한 적외선 평판 스캐너는 적외선 광원을 개별적으로 조사할 필요가 없으며, 최소 2mm 이상 되는 피사계 심도로 인하여 초점 문제가 없다. 또한 적외선 평판 스캐너는 일반 평판 스캐너와 마찬가지로 12800dpi의 고해상도를 만들어 낼 수 있다는 것 역시 장점으로 작용한다. 본 논문에서 개발한 적외선 평판 스캐너가 많은 분야에서 활용되기를 기대한다.

• Natural Product Sciences
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• 제17권4호
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• pp.328-336
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• 2011

A high-performance liquid chromatography (HPLC) with diode array detector (DAD) method was established for the discrimination of a folk medicine Forsythia suspensa and Forsythia viridissima. Five and three representative metabolites of the lignan and phenolic glycoside classes were selected for the analysis from F. suspensa and F. viridissima, respectively. The optimal chromatographic conditions were obtained on an ODS column (5 ${\mu}m$, $4.6{\times}250$ mm) with the column temperature at $40^{\circ}C$. The mobile phase was composed of methanol and 0.3% acetic acid using an isocratic elution with the flow rate 1 mL/min. Detection wavelength was set at 280 nm. All calibration curves showed good linear regression ($r^2$ > 0.996) within test ranges. Limits of detection (LOD) and limits of quantitation (LOQ) values were lower than 0.096 and 0.291 ${\mu}g/mL$, respectively. The developed method provided satisfactory precision and accuracy with overall intra-day and inter-day variations of 0.07-0.63% and 0.14-0.62%, respectively, and the overall recoveries of 97.79-102.46% for all of the compounds analyzed. In addition, effectiveness of diverse extraction methods was compared to each other for the development of standard analytical method. The verified method was successfully applied to the quantitative determination of representative metabolites in fifty-three commercial F. suspensa samples and fifteen commercial F. viridissima samples from diverse sources. The overall analytical results showed the unequivocal differences in bioactive constituents between F. suspensa and F. viridissima.

• 한국지하수토양환경학회지:지하수토양환경
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• 제7권2호
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• pp.35-44
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• 2002

유류로 오염될 위험성이 있는 지역에서 유류의 누출을 미리 감지하여 오염의 확산을 막기 위한 시스템을 개발하기 위하여, 유류에 상당량이 함유되어 있는 벤젠, 톨루엔, 에틸벤젠, 자일렌의 농도별 형광세기를 측정하였다. 이것은 단일방향족 탄화수소계 물질이 260nm대의 자외선영역의 빛을 흡수하여 290nm 파장 영역의 형광을 낸다는 원리를 이용한 것이었으나 실제 토양 시료의 형광을 측정할 때는 300-600nm파장 영역에서 형광이 나왔다 이것은 토양이 입자 물질로 구성되어 있기 때문에 나타나는 경향이라 사료된다. 흡광 영역이 비슷한 이 네 가지 단일 방향족 탄화수소계 물질들은 그 형광을 내는 파장 영역도 비슷하였으며, 토양시료의 형광세기는 오염시킨 농도가 증가함에 따라 증가하였다. 또한 이러한 경향은 토양 입자가 미세한 토양에서 더 뚜렷하게 나타났다. 따라서 본 측정 기술은 기존의 방법에 비하여 신뢰도가 높은 데이터를 얻을 수 있고, 간편하고 단순하여 한번의 설치로 주기적인 측정이 가능하므로 유류 오염의 위험이 있는 지역에서의 상시 측정장치로서 효과적일 것으로 판단된다.

• 한국결정학회지
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• 제11권4호
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• pp.212-223
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• 2000

A stochiometric mix of CuInTe₂ polycrystal was prepared in a honizonatal furnace. To obtain the single crystal thin films, CuInTe₂ mixed crystal was deposited on throughly etched GaAs(100) by the HWE system. The source and substrate temperatures were 610℃ and 450℃ respectively, and the thickness of the deposited single crystal thin film was 2.4㎛. CuInTe₂ single crystal thin film was proved to be the optimal growth condition when the excition emission spectrum was the strongest at 1085.3 nm(1.1424 eV) of photoluminescence spectrum at 10 K, and also FWHM of Double Crystal X-ray Rocking Curve (DCRC) was the smallest, 129 arcsec. The Hall effect on this sample was measured by the method of Van der Pauw, and the carrier density and mobility dependent on temperature were 9.57x10/sup 22/ electron/㎥, 1.31x10/sup -2/㎡/V·s at 293 K, respectively. The ΔCr(Crystal field splitting) and the ΔSo (spin orbit coupling splitting( measured at f10K from the photocurrent peaks in the short wavelength of the CuInTe₂ single crystal thin film were about 0.1200 eV, 0.2833 eV respectively. From the PL spectra of CuInTe₂ single crystal thin film at 10 K, the free exciton (E/sub x/) was determined to be 1064.5 nm(1.1647 eV) and the donor-bound exciton(D/sup 0/, X) and acceptor-bound exciton (A/sup 0/, X) were determined to be 1085.3 nm(1.1424 eV) and 1096.8 nm(1.1304 eV0 respectively. And also, the donor-acciptor pair (DAP)P/sub 0/, DAP-replica P₁, DAP-replica P₂ and self-activated (SA) were determined to be 1131 nm (1.0962 eV), 1164 nm(1.0651 eV), 1191.1 nm(1.0340 eV) and 1618.1 nm (0.7662 eV), respectively.

• 전자공학회논문지D
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• 제35D권6호
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• pp.63-71
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• 1998

본 논문에서는 Fe가 0.015Wt.%도핑된 LiNbO₃ 결정에서 2광파혼합(TWM:Two-Wave Mixing)을 통한 입사각에 따른 결합계수, 기록빔의 세기비에 따른 이득, 회절효율, 시간응답특성에 대한 해석 및 실험을 통해 고밀도 광메모리 소자로서 응용하기 위한 특성을 제시한다. 실험결과 514.5nm 파장에서 본 결정의 경우 14°에서 최대 결합특성을 보였고 이때의 최대결합계수는 6.9cm/sup -1/이다. 그리고, 632.8nm 파장의 빔으로 판독시 두 결합빔의 세기비가 0.1이고, 입사각이 140 일 때, 54.13%의 최대 회절효율을 얻었으며, 격자고정시 회절효율은 21.4% 이다. 또한, Fe-LiNbO₃ 결정을 높은 회절효율을 갖는 광메모리 소자로 적용하기 위해 가장 우수한 회절특성을 보이는 조건에서 각도 다중화 방식과 공간 광학 변조기를 이용한 광정보 저장응용실험 결과를 제시하였다.

• Journal of Preventive Medicine and Public Health
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• 제7권2호
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• pp.377-381
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• 1974

Determination of lead in urine is important in industrial hygiene and toxicology. Dithizone method has been principally used for the determination of lead in urine, which gives accurate results in skilful hands but is usually complex and time-consuming. Atomic absorption spectrophotometry is a new simple method and several procedures have been described. However, the influences of pH and the presence of chelating agents during treatment of lead poisoning are not clear. The purpose of this study was to find out the effect of pH and chelating agents on the determination of lead using Shimadzu atomic absorption/flame spectrophotometer, model AA-610. The results obtained were as follows: 1. The atomic absorption spectrophotometry(AAS) could be applied without prior acid digestion to specimens in the absence of chelating agents. The absorbance at $2,170\;{\AA}$, though more sensitive, was more noisy electronically. Therefore, we selected the wavelength of $2,833\;{\AA}$ plus scale expansion. 2. The optimal pH was in the range from 2 to 3. 3. The sensitivity was $0.075{\mu}g/ml/%$ and detection limit was about $0.2{\mu}g/ml$. 4. In the presence of EDTA, lead could not be completely determined without prior acid digestion. 5. On specimens from patients receiving penicillamine therapy, a comparison was made between the values obtained with dithizone method and AAS method with prior acid digestion. The results of comparison showed a very good agreement.