• Nuclear Engineering and Technology
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• 제52권4호
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• pp.856-862
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• 2020

Defect inspection system for industrial applications takes the important portion. Non-destructive inspection method has been significantly improved. Infrared thermography, as one of method for non-destructive inspection, can provide relatively precise data and quick inspection time. This study, it was performed to measure defect according to the measurement limit of the non-visible areas such as the back surface of the pipe using reflection plate using reflection plate based on Infrared thermography. The materials of the reflection plate were determined in consideration of the space limitation and the thermal characteristics, and defects were detected by the manufactured reflection plate. Detection of defect in non-visible area using the candidate materials for reflection plate was conducted.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.1545-1546
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• 2013

• Near Infrared Analysis
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• 제1권1호
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• pp.37-41
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• 2000

The purpose of this research was to develop a the reflection technique with near infrared (NIR) radiation for estimating soil components. NIR reflectance was scanned at 2nm intervals from 1100 to 2500nm with an InfraAlyzer 500 (Bran & Luebbe Co.). Over 400 soil sample from fields of different crops and land-use over Youngnam and Honam regions were used to obtain mean diffuse reflection of the soil for the calibration and validation of the calibration set in estimating moisture, organic matter (OM) and total nitrogen (T-N) of the soils. Multiple linear regression (MLR) was used to evaluate the correlation of NIR spectroscopy method. Reflection pattern of NIR spectra for finely sized sample (<0.5mm) and coarsely sized soil(<2mm) did not show much difference. The results showed that NIR spectroscopy and coarsely sized soil (<2mm) did not show much difference. The results showed that NIR spectroscopy could be used as a routine soil testing method in estimating OM, moisture, T-N in soil samples simultaneously.

• 센서학회지
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• 제31권4호
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• pp.255-259
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• 2022

In this study, we fabricated ZnS substrates with excellent transmittance in the mid-infrared region (3-5 ㎛) using hot pressing instead of conventional chemical vapor deposition (CVD). Diamond-like carbon (DLC) was coated on either one or both sides of the ZnS substrates to improve their mechanical properties and transmittance efficiency. To reduce the reflectance and further improve transmittance in the mid-infrared region, anti-reflection (AR) coating was designed for DLC/ZnS /AR and AR/ ZnS /AR structures. The coating structure, microstructure, and optical properties of the AR-coated ZnS substrates were subsequently investigated by employing energy dispersive X-ray spectroscopy, scanning electron microscopy, and Fourier-transform infrared (FTIR) spectroscopy. The FTIR spectroscopy results demonstrated that, in the mid-infrared region, the average transmittance of the samples with AR coating on one and both sides increased by approximately 18% and 27%, respectively. Thus, AR coating improved the transmittance of the ZnS substrates.

• 한국식품과학회지
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• 제24권5호
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• pp.404-407
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• 1992

이 연구의 목적은 식품성분의 분석을 위한 신속간편법으로 근적외선 반사 분광분석을 이용함에 있어 흡광도에 영향을 미치는 시료의 물리적, 화학적 요인을 규명하고자 한다. 온도를 달리한 정육시료를 근적외선 파장 범위인 $1100{\sim}2500\;nm$에서 흡광도를 측정한 결과 온도가 상승함에 따라 흡광도가 대체로 증가하였다. 시료의 세절시간이 길어질수록 흡광도는 감소하였다. 정육, 육단백질, 지방 및 수분의 근적외선 스펙트럼에서 나타난 흡수띠는 분자내의 C-H, N-H, O-H 및 C=O 결합의 overtone과 combination 진동에 의한 것으로 확인되었다. 정육 구성성분 중 육단백질의 흡광도가 가장 낮았으며 지방은 1700 nm와 2300 nm 부근에서 특징적인 ${\cdot}CH_2{\cdot}$ 흡수띠를 보였고 1450 nm와 1930 nm에서 물분자에 의한 강한 흡수띠가 나타났다. 결과적으로 정육의 근적외선 스펙트럼의 흡광도는 함유된 수분과 지방에 의한 영향을 많이 받는 것으로 사료된다.

• 한국산학기술학회논문지
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• 제16권6호
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• pp.4121-4124
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• 2015

에너지 절감 유리창에서는 근적외선 차단 기능이 요구되고 있다. 본 연구에서는 근적외선 반사를 위한 광학 박막의 설계, 제작 및 광학적 특성이 연구 되었다. 광학 박막은 저굴절률막과 고굴절률막의 적층 박막 구조로 설계하였다. 설계구조에 따라 RF 스퍼터링 방법을 이용한 $SiO_2$와 $TiO_2$ 박막의 증착 실험이 수행되었고 파워에 따른 증착 조건 파라미터에 따라서 제작된 스퍼터링 박막의 특성이 분광타원기, 원자현미경, 분광기로 분석되었다. 적층박막 구조의 설계는 $SiO_2$와 $TiO_2$의 고굴절률 박막/저굴절률 박막/고굴절률 박막의 적층 구조로서 근적외선 차단 다층막이 설계되었고 시뮬레이션 되었다. 시뮬레이션 결과 파장대역 930nm에서 1682nm의 범위에서 반사율30%이상이 관찰되었다. 시뮬레이션 결과를 토대로 제작된 삼층 구조의 박막은 파장 대역이 930nm에서 1525nm범위 대역에서 반값 전폭의 반사율 33%이상을 구현할 수 있었다.

• Near Infrared Analysis
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• 제1권2호
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• pp.35-39
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• 2000

The purpose of this research was to find out suitable soil sample preparation and sample holding tools for NIR reflection radiation for estimating soil components. NIR reflectance was scanned at 2nm intervals from 1,100 to 2,500nm with an InfraAlyzer 500(Bran+Luebbe Co.). Coarse(2.0mm) and fine(0.5mm) soil sample and various sample holding tools were used to obtain mean diffuse reflection of the soil for the calibration and validation of the calibration set in estimating moisture, organic matter and total nitrogen of the soils. Multiple linear regression was used to obtain the best correlation of NIR spectroscopy method. Correlation of NIR spectroscopy method. Correlation of NIR spectra for finely and coarsely sized soil did not show much difference. The standard errors of prediction(SE) using different types of sample holding tools for organic matter, total nitrogen and soil moisture were better than 0.765, 0.041 and 0.63% respectively. From the results it can be concluded that NIR spectroscopy with flow type cell could be used as a fast routine testing method in quantitative determination of organic matter, total nitrogen and soil moisture.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 추계 학술논문 발표대회
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• pp.37-38
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• 2017

In Infrared rays, which are 50% of sunlight, act as heat rays to heat buildings. Solar heat paint is widely used to protect buildings from sunlight. Solar heat coatings are used to block buildings form sunlight. Solar heat paints are classified as heat-reflective paints and heat-insulating paints according to the differential thermal mechanism. In this study, we study the thermal differential mechanism by analyzing the temperature change of the coated steel plate and the solar reflection spectrum on the surface. In this experiment, exposed steel plate, heat-reflective coated steel plate, heat-insulating coated steel plate, and general paint coated steel plate were used. As a result, when the infrared rays of 780nm ~ 1400nm were irradiated, the heat reflective paint had a temperature lower by 10 degrees than other paints. Analysis of the reflection spectrum of the paint shows that the heat paint is lower in heat than other paints because it has higher reflectance of light and absorbs much of the infrared rays.

• Journal of Biosystems Engineering
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• 제24권3호
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• pp.259-266
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• 1999

This research was carried out to investigate the possibility of real time rice milling ratio measurement using the spectral reflection characteristics. In this study, various methods were compared such as \circled1 using the whiteness meter, \circled2 using the colorimeter, \circled3 using the Visible and the NIR reflection spectrum. The samples were milled in the domain of 84~96% by 0.5% interval classified by milling ratio. The NMG treatment method required about 20 minutes to determine the milled ratio and r2 was 0.0028 to 0.7959 that was very low. In case of whiteness meter, r2 was high but speed of measurement was 5 minutes that was very low. Measurement with the colorimeter required about 5 minutes and r2 was 0.60 to 0.85 that was low. The reflection spectrum were measured in the range of 400~2,500nm with 2nm interval and the MLR model with six-wavelength obtained from first derivative of spectra gave the best results(r2 = 0.967, SEP = 0.729%)

• International Journal of Concrete Structures and Materials
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• 제7권2호
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• pp.119-125
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• 2013

Carbonation is a natural ageing process for cement. This study focuses on how the carbonation rate varies with selected hydration times and atmospheric conditions during the early stages of reacting dried cement paste. Diffuse reflection Fourier transform infrared spectroscopy is shown to be a suitable technique to monitor the formation of carbonates in cement. Combined with a previously developed freeze drying technique, carbonation can be studied at specific hydration stages. In ambient air both calcium hydroxide and calcium silicate hydrate (C-S-H) in cement are carbonated. Increased hydration time enhances the carbon dioxide uptake, which indicates that the calcium in the hydration products reacts more easily than the calcium in the clinker phase. In a humid $CO_2$ atmosphere, the carbonation process is so pronounced that it decomposes C-S-H into calcium carbonate and silica. In a moist $N_2$ atmosphere no carbonation occurs, but the sulfate chemistry of the cement seems to be affected due to the formation of ettringite.