• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1628-1628
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• 2001

Near infrared (NIR) spectroscopy is a powerful technique for non-destructive analysis that can be obtained in a wide range of environments. Recently, NIR measurements have been utilized as probe for quantitative analysis in agricultural, industrial, and medical sciences. In addition, it is also possible to make practical application on NIR for molecular structural analysis. In this work, Fourier transform near infrared (FT-NIR) measurements were carried out to utilize extensively in the relative amounts of different secondary structures were employed, such as Iysozyme, concanavalin A, silk fibroin and so on. Several broad NIR bands due to the protein absorption were observed between 4000 and $5000\;^{-1}$. In order to obtain more structural information from these featureless bands, second derivative and Fourier-self-deconvolution procedures were performed. Significant band separation was observed near the feature at $4610\;^{-1}$ ,. Particularly the peak intensity at $4525\;^{-1}$ shows a characteristic change with thermal denaturation of fibroin. The structural information can be also obtained by mid-IR and CD spectral. Correlation of NIR spectra with protein structure is discussed.

• Journal of Biosystems Engineering
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• 제41권1호
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• pp.51-59
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• 2016

Purpose: This study examined the performance of two spectroscopy methods and multivariate classification methods to discriminate viable pepper seeds from their non-viable counterparts. Methods: A classification model for viable seeds was developed using partial least square discrimination analysis (PLS-DA) with Fourier transform near-infrared (FT-NIR) and Raman spectroscopic data in the range of $9080-4150cm^{-1}$ (1400-2400 nm) and $1800-970cm^{-1}$, respectively. The datasets were divided into 70% to calibration and 30% to validation. To reduce noise from the spectra and compare the classification results, preprocessing methods, such as mean, maximum, and range normalization, multivariate scattering correction, standard normal variate, and $1^{st}$ and $2^{nd}$ derivatives with the Savitzky-Golay algorithm were used. Results: The classification accuracies for calibration using FT-NIR and Raman spectroscopy were both 99% with first derivative, whereas the validation accuracies were 90.5% with both multivariate scattering correction and standard normal variate, and 96.4% with the raw data (non-preprocessed data). Conclusions: These results indicate that FT-NIR and Raman spectroscopy are valuable tools for a feasible classification and evaluation of viable pepper seeds by providing useful information based on PLS-DA and the threshold value.

• 대한화학회지
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• 제55권4호
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• pp.644-649
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• 2011

Polyaniline/$SiO_2$ 촉매를 이용하여, acetophenone, aromatic aldehydes와 aromatic amines을 에탄올 용매 속에서 반응시켜서 다양한 various ${\beta}$-amino ketones을 one-pot mannich 반응을 수행하였으며, 이 반응을 위해 silica가 충진된 여러 가지 종류의 wt% polyaniline을 화학적인 산화방법에 의해 합성하였다. 합성한 촉매는 thermal analysis(TG-DTA), X-ray diffraction (XRD), scanning electron microscopy(SEM) energy dispersive spectroscopy(EDS), 및 Fourier transform infrared spectroscopy (FT-IR) 방법으로 확인하였으며, 촉매의 용매에 대한 안정도 UV-Visible spectroscopy로 측정하였다. Polyaniline/$SiO_2$ 촉매를 이용하는 합성 방법은높은 수율로 얻어지며, work up이 쉽고, 독성이 없으며, 쉽게 회수하여 재사용이 가능하다.

• 약학회지
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• 제47권6호
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• pp.461-468
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• 2003

A method is described for measuring clinically relevant levels of glucose in a pH 7.4 phosphate buffer by nearinfrared (NIR) absorption spectroscopy. Three types of NIR spectrometer, dispersive type, photo-diode array (PDA) type, and fourier transform (FT) type spectrometer were used and the performance was compared. Spectra were collected with a cuvette cell or quartz liquid fiber of 1 mm or 2 mm optical pathlength as transmittance method. Glucose absorption band appeared at second overtone, first overtone, and combination region for all systems. By use of the multivariate technigue of partial least squares (PLS) regression, glucose concentrations can be determined with a 16, 44, and 9.1 mg/d l standard error of prediction for dispersive type, photo-diode array type, and fourier transform type system, respectively. Sensitivity of spectrometer was evaluated by absorbance for the difference of 10 mg/d l glucose. Three absorption bands, second overtone, first overtone, and combination region were suited to three types systems, dispersive type, photo-diode array type, and fourier transform type systems, respectively. This investigation showed that three types NIR spectrometer were proper method for identification and quantitative analysis of glucose and possible for noninvasive blood glucose monitoring.

• 농업과학연구
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• 제50권4호
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• pp.675-696
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• 2023

Terpenoids, also referred to as terpenes, are a large family of naturally occurring chemical compounds present in the essential oils extracted from medicinal plants. In this study, a nondestructive methodology was created by combining ATR-FT-IR (attenuated total reflectance-Fourier transform infrared), and Raman spectroscopy for the terpenoids assessment in medicinal plants essential oils from ten different geographical locations. Partial least squares regression (PLSR) and support vector regression (SVR) were used as machine learning methodologies. However, a deep learning based model called as one-dimensional convolutional neural network (1D CNN) were also developed for models comparison. With a correlation coefficient (R²) of 0.999 and a lowest RMSEP (root mean squared error of prediction) of 0.006% for the prediction datasets, the SVR model created for FT-IR spectral data outperformed both the PLSR and 1 D CNN models. On the other hand, for the classification of essential oils derived from plants collected from various geographical regions, the created SVM (support vector machine) classification model for Raman spectroscopic data obtained an overall classification accuracy of 0.997% which was superior than the FT-IR (0.986%) data. Based on the results we propose that FT-IR spectroscopy, when coupled with the SVR model, has a significant potential for the non-destructive identification of terpenoids in essential oils compared with destructive chemical analysis methods.

• 한국염색가공학회지
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• 제6권2호
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• pp.17-23
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• 1994

Carboxylic acid group gradient surface where the density of carboxylic acid groups changes gradually along the sample length was prepared. Carboxylic acid group gradient surface was produced by the treatment of low density polyethylene sheet using a corona with gradually increasing power, followed by the grad polymerization of acrylic acid. The prepared gradient surface was characterized by the measurement of water contact angle, Fourier-transform infrared spectroscopy in the attenuated total reflectance mode, and electron spectroscopy for chemical analysis.

• Bulletin of the Korean Chemical Society
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• 제27권12호
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• pp.2101-2103
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• 2006

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.409.1-409.1
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• 2002

For the development of a biocompatible nano-scale drug carrier. hydrophilic polysaccharide pullulan was hydrophobized by the conjugation with fatty acid. The synthesized polymers were characterized by the measurements of fourier transform infrared (FT -IR) spectroscopy and 1H -nuclear magnetic resonance (NMR) spectroscopy. In aqueous solution. hydrophobically modified puliulan was self-assembled and structured into the core-shell type nanoparticles. (omitted)

• 한국결정성장학회지
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• 제9권6호
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• pp.570-573
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• 1999

Ca nitrate와 인산을 혼합한 용액을 졸-겔법을 이용하여 Si(100) 기판 위에 스핀 코팅하여 열처리 함으로써 의치공 재료에 응용되는 하이드록시아파타이트 박막을 제조하였다. Si 기판 위에 아이드록시아파타이트막을 코팅하여 건조시킨 다음, $500^{\circ}C$에서 10분간 초벌구이 열처리를 하였다. X-선 회절 분석을 이용하여 $500^{\circ}C$에서 하이드록시아파타이트 상의 생성을 확인하였고, $500^{\circ}C$~$700^{\circ}C$ 및 $900^{\circ}C$에서 각각 tricalcium phosphate상의 생성을 확인하였다. FTIR(Fourier transform infrared spectroscopy)의 결과를 바탕으로 열처리 온도 증가에 따른 탄소량의 변화와 결정화도의 증가를 확인하려 한다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.147.1-147.1
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• 2016

Hydrophobic thin films are variously applicable for encapsulation of organic devices and water repulsive glass, etc. In this work, the stability of hydrophobic characteristics of plasma polymerized tetrakis (trimethylsilyloxy) silane (ppTTMSS) thin films were investigated. The films were deposited with plasma enhanced chemical vapor deposition (PECVD) on the glass. The deposition plasma power and deposition pressure was 70 W and 600 mTorr, respectively. Thereafter, deposited films were treated by 248nm KrF excimer laser. Stability of hydrophobic properties of plasma polymerized tetrakis(trimethylsilyloxy)silane film surface was tested by excimer laser irradiation, which is thought to simulate severe outdoor conditions. Excimer laser irradiation cycles changed from 10 to 200 cycles. The chemical structure and hydrophobicity of ppTTMSS films were analyzed by using Fourier transform infrared (FTIR) spectroscopy and water contact angle (WCA) measurement, respectively. Absorption spectra peaks and WCA of excimer laser treated ppTTMSS films did not change notably. These results show that our ppTTMSS films possess stable hydrophobic properties.