• Food Science and Preservation
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• v.12 no.6
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• pp.608-612
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• 2005

Fourier transform-near infrared (FT-NIR) spectroscopy is a simple, rapid, non-destructive technique which can be used to make quantitative analysis of chemical composition in grain. An interest in total dietary fiber (TDF) of grain such as rice has been increased due to its beneficial effects for health. Since measuring methods for TDF content were highly depending on experimental technique and time consumptions, the application of FT-NIR spectroscopy to determine TDF content in milled rice. Results of enzymatic-gravimetric method were $1.17-1.92\%$ Partial least square (PLS) regression on raw NIR spectra to predict TDF content was developed Accuracy of prediction model for TDF content was certified for regression coefficient (r), standard error of estimation (SEE) and standard error of prediction (SEP). The r, SEE and SEP were 0.9705, 0.0464, and 0.0604, respectively. The results indicated that FT-NIR techniques could be very useful in the food industry and rice processing complex for determination of TDF in milled rice on real time analysis.

• Proceedings of the Optical Society of Korea Conference
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• 2000.08a
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• pp.222-223
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• 2000

지금까지 gold-coated 반사체, cusp-shaped 반사체, 복합 포물 반사체(CPC), 난반사 공동체 등 다양한 형태의 반사체가 횡펌핑을 이용한 Nd:YAG 레이저의 개발을 위하여 고안되어졌다. 횡여기되는 Nd:YAG 레이저의 광학적 효율은 반사체의 형태, 다이오드 레이저의 파장, Nd:YAG 결정의 지름, Nd$^3$의 도핑농도에 따라 영향을 받는다.$^{(1)}$ 본 연구에서는 고출력의 횡여기 Nd:YAG 레이저를 개발할 목적으로 광여기 공동으로 사용된 난반사 공동체의 내부지름과 레이저 매질인 Nd:YAG 결정의 흡수계수 등 매개변수를 변화시켜 흡수분포와 출력을 계산하였으며, 이러한 매개변수들이 기울기 효율에 미치는 영향을 수치 해석적으로 연구해 보았다. 광선추적법에서 사용한 매개변수 중에서 다이오드 레이저의 파장은 808 nm이고, 반사율은 90%이며, 여기 다이오드 출력은 1080 W이다. 난반사 공동체$^{(2)}$ 의 반사율은 95.7%이고, 결정의 투과율은 90%이며, 결정의 반지름은 2.5 mm이다. 사용된 여기 구조도는 그림 1과 같다. 여기헤드는 Nd:YAG 결정, 난반사 공동체, 그리고 3개의 360 W급 다이오드 어레이들로 구성되어 있다. (중략)

• Journal of the Microelectronics and Packaging Society
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• v.4 no.2
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• pp.71-78
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• 1997

본 논문에서는 InGaAsP 에피막에서 도핑 농도와 에피막의 미세조직구조가 photoluminescence (PL) 스펙트럼의 위치 및 형상에 어떤 영향을 미치는가를 연구하였고, 그 결과를 설명하기 위해 가능한 모델을 제시하였다. InGaAsP 에피막(발진파장 ~1.3$\mu$m) 을 액상증착법(liquid phase epitaxy, LPE)으로 성장하여 9K에서 PL측정을 했을 때 InGaAsP 활성층 내 Zn 억셉터의 유무에 따라 PL 피크의 위치가 최대 30nm (24meV)까지 shift하고 피크의 선폭도 넓어지는 현사을 발견하였다. 이와같은 피크 분산현상은 inGaAsP 에피막이 유기금속 기상증착법으로 성장되거나 Zn로 고농도로 도핑되거나 고온에서 어닐링 될 경우 대폭 감소하였다. 이를 설명하기 위해 여러 가지 모델을 설정하여 실험을 하였으며 이 중 InGaAsP 에피막의 미세조직구조 특히 Spinodal 분해에 의한 조성이 모듈레이션과 Zn의 상호작용의 관계가 이 현상을 설명하는 데 가장 적절하다는 것을 밝혔다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.1
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• pp.13-19
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• 1996

This study was conducted to establish the rapid determination method for major components of maturing covered barley grains, and to improve the efficiency of selection in barley breeding. Near Infrared Reflectance Spectroscopy (NIRS) is an established, economical and nondestructive technique applied widely to the food and feed industry. 34 barley lines were sampled at 5 day-interval from 25 to 35 days after heading. A standard regression analysis for the data obtained by analytical laboratory methods and NIRS method was carried out to get a useful calibration equation. The simple significant correlation between these two methods at 25 days after heading was recognized in starch and $\beta$-glucan contents. At 30 days after heading the data obtained by two methods showed significant correlation in starch, $\beta$-glucan and protein contents. Analyzed data and that from NIRS method at 35 days after heading was significantly correlated in starch and protein contents. It was concluded that the applicability of NIRS method for the components analysis in maturing barley grains was different depending on maturing stages and components.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.101-101
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• 2011

투명전도성산화물(transparent conducting oxides, TCOs) 박막으로써 널리 쓰이는 산화인듐주석(indium tin oxide, ITO)은 전기 전도성과 광 투과성이 우수하여 주로 유기발광다이오드(organic light-emitting diode, OLED)의 전극, 발광다이오드(light-emitting diode, LED)의 current spreading 층 및 태양전지(solar cell)의 윈도우층(window layer) 등의 광전자 소자로 응용되고 있으나, 고가의 indium 가격과 인체에 유해한 독성 등이 문제점으로 지적되고 있다. 따라서 indium의 함량을 저감한 새로운 조성의 TCO 또는 indium을 함유하지 않은 친환경적인 TCO 대체 재료 개발의 필요성이 증대되고 있다. 이러한 재료 중 하나인 AZO (Al-doped zinc oxide, $Al_2O_3$: 2 wt.%)는 3.82eV의 넓은 에너지 밴드갭을 가지며, 가시광선 및 근 적외선 파장 영역에 대하여 90% 이상의 높은 투과율을 나타낸다. 또한, 습식식각이 가능하며, 매우 풍부하여 원가가 매우 저렴하고, 독성이 없다. 본 연구에서는 박막 증착율이 높고, 제작과정의 조정이 용이한 RF magnetron 스퍼터를 이용하여 glass 기판 위에 AZO 박막을 성장하고, $N_2$ 분위기에서 다양한 온도 조건에서 열처리(rapid thermal annealing, RTA)하여 전기 및 광학적 특성에 대하여 비교 분석하였다. 또한, 이후에 기존의 성장방법과 달리 고가의 진공 장비를 사용하지 않고, 저온에서도 간단한 구조의 장비를 이용하여 균일한 나노구조를 성장시킬 수 있는 전기화학증착법(electrochemical deposition)으로 AZO 박막위에 ZnO 나노로드를 다양한 성장조건에 따라 성장시켜 광학적 특성을 비교 분석하였다.

• Korean Journal of Food Science and Technology
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• v.38 no.2
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• pp.165-168
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• 2006

Fourier transform-near infrared spectroscopy (FT-NIRS) was evaluated for determination of total dietary fiber (TDF) content of brown rice. Enzymatic-gravimetric method was suitable to obtain reference values for calibration of NIR at 1,000-2,500 nm range. Standard error of laboratory procedure ranged 0.17 to 0.72%. Partial least square (PLS) regression was used to develop the calibration equations. Regression was performed automatically using NIRCal chemometric software. Accuracy of prediction model for TDF content was certified for regression coefficient (r), standard error of estimation (SEE) and standard error of prediction (SEP), showing 0.9780, 0.0636, and 0.0642, respectively. This prediction model can be used for determination of TDF in brown rice and would be useful for real-time analysis in food industry.

• Korean Journal of Soil Science and Fertilizer
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• v.34 no.2
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• pp.145-146
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• 2001

본 분석방법은 토양중에 방향성화합물을 함유한 유류 존재를 스크리닝하는 방법으로 ASTM(The American Society for Testing and Materials)에 등록되어 있으며, 수분 제거제를 이용하여 토양수분에 의한 정량 오차를 줄이고 UV-Spectrophotometer로 정량한다. 오염된 유류의 종류를 알고 있으나 동일한 유류를 구하지 못할 경우에는 일반적으로 동일종에서 얻어진 계수로 농도를 추정하며, 오염된 유류의 특성을 모를 경우에는 본 방법으로 오염여부 판단만이 가능하다. 그러나 토양에 오염된 것과 동일한 유류로 검량선을 작성할 경우에는 대략적인 정량도 가능하며, 분석방법을 요약하면 다음과 같다. 일정량의 토양시료에 CaO를 첨가하여 토양수분에 의한 영향을 제거한 뒤 이소프로필알콜(isopropyl alcohol)로 추출하여 여과한다. 여과액을 254nm의 UV파장에서 흡광도를 측정하여 오염된 것과 동일한 유류로 작성된 검량선을 이용하여 정량한다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.5
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• pp.489-494
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• 1994

Near Infrared Reflectance Spectroscopy(NIRS) has been used as a tool for the rapid, accurate, protein assay of malting barley. NIRS used in this study was filter type instruments, Neotec 102. The objective of this study was to obtain the best calibration equation, for the rapid, ease and accurate protein content analysis of malting barley using NIRS system. The optimum wavelength for protein content analysis used NIRS were 2095nm, 2095/1941nm, 2095/1941/2282nm, 2905/1941/2282/2086nm, respectively. Mean protein content with this calibration equation in NIRS analysis was 10.59%, while 10.60% in Micro-Kjeldahl one. The range of protein content in Micro-Kjeldahl was 8.66~12.66% and that in NIRS was 8.80~12.35%. When 18 other varieties produced in 1992 were analysed with 2095nm, 2095/1941nm, 2095/1941/2282nm, 2095/1941/2282/2086nm equation, standard deviation of difference (SDD)and standard error of performence(SEP) and $R^2$ values were 0.47, 0.43, 0.95, respectively. Both the mean protein content by Micro-Kjeldahl and by NIRS was 10.25%. With this equation, analysied 31 varities produced in 1993, SDD and SEP and r values were 0.69, 0.67, 0.91, respectively, and that bias value was 0.65. In this analysis, mean protein content by Micro-Kjeldahl was 10.17% and by NIRS was 10.81%. The range of protein content in Micro-Kjeldahl was 7.58~14.29%, What that in NIRS was 8.63~13.93%. After adjusted bias in the best calibration equation, mean protein content of Micro-Kjeldahl was 10.17% and that of NIRS was 10.09%, without variance of SDD, SEP and r values.

• Analytical Science and Technology
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• v.22 no.6
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• pp.458-463
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• 2009

A new quantitative analytical method has been established for the rapid determination of flumethrin in honey products using high performance liquid chromatography (HPLC). Sample was dissolved and extracted in the mixture of water and acetonitrile (1:2). The extracts were purified with silica cartridge eluted by the mixture of hexane and dichloromethane (55:45) and analyzed at 266 nm using HPLC. The percentage recovery of flumethrin spiked in sample was found to be 90.2-97.8% and the limit of detection is 0.003 mg/kg. We validated the method for the linearity, the precision and the reproducibility. We investigated the residues of flumethrin in honey products retailed in market using the established method. Flumethrin was not detected at all among 130 samples of honey.

• Solar Energy
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• v.10 no.2
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• pp.59-68
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• 1990

In this paper, photoconductive pure CdSe films and CdSe films doped with various impurities are fabricated by vaccum deposition and subsequent heat treatment in vaccum. The substrate is kept at $200^{\circ}C$ during deposition and temperature generally makes the films more photoconductive. The photocurrent of the films increase linearly with light illumination. Spectral response of photoconductivity is measured at the wave length range of 380nm to 850nm. The maximum response is found at 700nm in pure CdSe films, but it shifts to the longer wavelength in impurity-doped CdSe films. Photo-response of the pure CdSe films are more sensitive at lower temperature, while the impurity-doped films show the opposite trend.