• 제목/요약/키워드: fourier transform infrared

검색결과 1,268건 처리시간 0.029초

Rapid discrimination of commercial strawberry cultivars using Fourier transform infrared spectroscopy data combined by multivariate analysis

  • Kim, Suk Weon;Min, Sung Ran;Kim, Jonghyun;Park, Sang Kyu;Kim, Tae Il;Liu, Jang R.
    • Plant Biotechnology Reports
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    • 제3권1호
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    • pp.87-93
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    • 2009
  • To determine whether pattern recognition based on metabolite fingerprinting for whole cell extracts can be used to discriminate cultivars metabolically, leaves and fruits of five commercial strawberry cultivars were subjected to Fourier transform infrared (FT-IR) spectroscopy. FT-IR spectral data from leaves were analyzed by principal component analysis (PCA) and Fisher's linear discriminant function analysis. The dendrogram based on hierarchical clustering analysis of these spectral data separated the five commercial cultivars into two major groups with originality. The first group consisted of Korean cultivars including 'Maehyang', 'Seolhyang', and 'Gumhyang', whereas in the second group, 'Ryukbo' clustered with 'Janghee', both Japanese cultivars. The results from analysis of fruits were the same as of leaves. We therefore conclude that the hierarchical dendrogram based on PCA of FT-IR data from leaves represents the most probable chemotaxonomical relationship between cultivars, enabling discrimination of cultivars in a rapid and simple manner.

Study on Rapid Measurement of Wood Powder Concentration of Wood-Plastic Composites using FT-NIR and FT-IR Spectroscopy Techniques

  • Cho, Byoung-kwan;Lohoumi, Santosh;Choi, Chul;Yang, Seong-min;Kang, Seog-goo
    • Journal of the Korean Wood Science and Technology
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    • 제44권6호
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    • pp.852-863
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    • 2016
  • Wood-plastic composite (WPC) is a promising and sustainable material, and refers to a combination of wood and plastic along with some binding (adhesive) materials. In comparison to pure wood material, WPCs are in general have advantages of being cost effective, high durability, moisture resistance, and microbial resistance. The properties of WPCs come directly from the concentration of different components in composite; such as wood flour concentration directly affect mechanical and physical properties of WPCs. In this study, wood powder concentration in WPC was determined by Fourier transform near-infrared (FT-NIR) and Fourier transform infrared (FT-IR) spectroscopy. The reflectance spectra from WPC in both powdered and tableted form with five different concentrations of wood powder were collected and preprocessed to remove noise caused by several factors. To correlate the collected spectra with wood powder concentration, multivariate calibration method of partial least squares (PLS) was applied. During validation with an independent set of samples, good correlations with reference values were demonstrated for both FT-NIR and FT-IR data sets. In addition, high coefficient of determination (${R^2}_p$) and lower standard error of prediction (SEP) was yielded for tableted WPC than powdered WPC. The combination of FT-NIR and FT-IR spectral region was also studied. The results presented here showed that the use of both zones improved the determination accuracy for powdered WPC; however, no improvement in prediction result was achieved for tableted WPCs. The results obtained suggest that these spectroscopic techniques are a useful tool for fast and nondestructive determination of wood concentration in WPCs and have potential to replace conventional methods.

중적외선 분광학을 이용한 토양 내의 질산태 질소 정량분석 (Direct Determination of Soil Nitrate Using Diffuse Reflectance Fourier Transform Spectroscopy (DRIFTS))

  • 최은영;김경웅;홍석영;김주용
    • 한국토양비료학회지
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    • 제41권4호
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    • pp.267-272
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    • 2008
  • 현장에서의 토양 측정을 위해서는 전처리 과정이 짧을수록 유리하므로 최대한 처리를 하지 않은 토양 시료에 대해 질산태 질소의 측정과 그에 맞는 정량화 방법을 제안하였다. 건조 토양을 분광분석에 그대로 사용하는 경우 산란, 분산되는 빛의 양이 많고 노이즈도 증가하므로 Diffuse reflectance 모드 (Diffuse reflectance infrared Fourier transform spectroscopy: DRIFTS)로 측정하였다. 토양 자체가 나타내는 분광 피크에 의해 질산염의 피크가 가려지는 간섭효과를 보완하기 위해 DRIFTS 스펙트럼에 1차 도함수를 적용하였으며, $1500-1200cm^{-1}$ 영역에서 질산염에 의한 신호의 향상이 확인되었고, 이를 이용해 다변량 회귀분석 모델 (PLSR)을 적용하여 정량화를 수행하였다. 1차 도함수를 이용한 분석모델에서도 각기 다른 종류의 토양을 적용하였을 때 결과치의 신뢰도가 감소하는 결과가 나타났다. 대표적인 토양으로 사질 (sand), 미사질 (sandy loam), 토탄질 (peat), 점토질 (clay) 토양에 대해 각각의 스펙트럼을 특성화하여 해당되는 정량모델을 적용하였다. 그 결과 다양한 종류의 토양에 대한 정량분석의 신뢰도가 향상되었다 ($R^2$>0.95, RPD>6.0). 스펙트럼의 신호처리와 토양 특성별 정량모델의 적용을 통해 현장 시료에 가까운 상태의 토양 질산염을 보다 빠르고 간단하게 평가할 수 있을 것으로 기대되며, 향후에 보다 다양한 조건의 토양에 대해 분광학적 분석을 수행하여 라이브러리가 구축된다면 이러한 기술의 확대 적용이 가능할 것으로 사료된다.

열전도성 실리콘 고무의 전압-전류 특성 (Properties of Current due to Voltage in Heat Conductive Silicone Rubber)

  • 이성일
    • 한국전기전자재료학회논문지
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    • 제27권9호
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    • pp.576-581
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    • 2014
  • This study used the heat conductive silicone rubber sample of 0.95 mm thickness to research the properties of current by changing voltage. When the 1, 10, 30, 60, and 90 minute have passed, the running current has been measured through the applied voltage range of 200 V~800 V on setting temperature of $110^{\circ}C{\sim}170^{\circ}C$. As the temperature increased in applied voltage of 800 V, so did the current value according to time in proportion to the increasing temperature. In an analysis of FT-IR (fourier transform infrared) spectrum, the hydroxyl radicals group(O-H) was created by effects of the hydrogen that methyl group is eliminated by addition of the cross-linking agent peroxide.

Preparation and Characterization of Thin Films by Plasma Polymerization of Hexamethyldisiloxane

  • Lee, Sang-Hee;Lee, Duck-Chool
    • E2M - 전기 전자와 첨단 소재
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    • 제11권10호
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    • pp.66-71
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    • 1998
  • Plasma polymerized hexamethyldisiloxane (PPHMDSO) thin films were produced using an electrode capacitively coupled apparatus. Fourier transform infrared spectroscopy analysis indicated that the thin film spectra are composed not only of the corresponding monomer bands but also of several new bands. Auger electron spectroscopy analysis indicated that the permeation depth of aluminum into the films is ca. 30nm when top electrode is deposited by evaporation aluminum. The increase of relative dielectric constant and decrease of dielectric loss tangent with the discharge power is originated from high cross-link of the films.

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FTIR 분광용 간섭계의 샘플링 잡음 영향 분석 (Analysis of sampling noise effect of Interferometer on FTIR Spectrometer)

  • 배효욱;박도현;나성웅;최승기
    • 대한전자공학회논문지SD
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    • 제44권4호
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    • pp.10-17
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    • 2007
  • FTIR 분광계는 간섭계를 사용하여 표적 물질에 대한 간섭무늬를 획득하고, 이를 푸리에 변환함으로써 기체상태 물질의 적외선 영역 스펙트럼을 획득하기 위한 유용한 기법이다. 본 논문에서는 불규칙적 위치에서 간섭무늬 샘플링에 관하여 고속 스캔 간섭계의 신호처리에서의 샘플링 노이즈 영향에 대한 연구와 이에 대하여 실험적으로 검증 하였다.

분전반의 화염에 의한 소손패턴 분석 (Damage Pattern Analysis of Voltage Cabinet Panel due to Flame)

  • 김동욱;이기연;김향곤;김만건
    • 한국화재조사학회논문지
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    • 제11권1호
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    • pp.37-40
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    • 2008
  • 본 연구는 저압 분전함내에서 발생한 사고사례를 분석하여 사고의 메커니즘과 사고특성 등을 연구하여 사고 패턴을 제시함으로서 전기설비 사고 원인 분석 및 진단을 위한 자료를 확보하고자 하였다. 이를 위해 금속현미경, X-ray, FI-IR 등의 분석을 하였다.

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저압 분전반의 화염에 의한 소손패턴 분석 (Damage Pattern Analysis of Low Voltage Cabinet Panel due to Flame)

  • 김동욱;이기연;김동우;길형준;김향곤
    • 한국화재소방학회:학술대회논문집
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    • 한국화재소방학회 2008년도 춘계학술논문발표회 논문집
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    • pp.269-272
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    • 2008
  • This paper deals with damage patterns of cabinet panel for low voltage deteriorated by flame. In order to analyze damage patterns, we used Metallurgical Microscope, x-ray system, and Fourier Transform Infrared spectroscopy. Firstly, Metallurgical microscope was used for analysis of electrical causes, such as electric short and overload. Secondly, X-ray system was used for analysis of internal characteristics of circuit breakers. Lastly, Fourier Transform Infrared spectroscopy was used for analysis of damage direction by flame. The following results were obtained.

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푸리에변환 적외선분광분석법에 의한 누설전류의 발생 원인에 대한 연구 (Study on the Generation of Leakage Current by the Fourier Transform Infrared Analysis)

  • 오데레사
    • 한국전기전자재료학회논문지
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    • 제20권6호
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    • pp.514-519
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    • 2007
  • The surfaces of $SiO_2$ films were treated by PMMA diluted solutions, and analyzed the chemical shift from Fourier Transform Infrared Spectrometer. The $SiO_2$ film treated by PMMA diluted solution changed the properties of the surface, and showed the blue and red shift according to the concentration of PMMA. The C-H bond elongation effect due to the high electro-negative atom chlorine showed the red shift, and makes the final material with the cross-link structure. The leakage current was efficiently reduced at the sample No 7 with the red shift, witch depends on the electron deficient group.