研究者詳細 - 土川　覚

論文 - 土川　覚

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Coming full circle: back to basics in the application of near infrared spectroscopy to the forest and wood products sector

Meder, R; Tsuchikawa, S

JOURNAL OF NEAR INFRARED SPECTROSCOPY 24 巻 ( 6 ) 頁： V - VII 2016年12月

Determination of optical parameters and moisture content of wood with visible-near infrared spectroscopy 査読有り

Haddadi, A; Hans, G; Leblon, B; Pirouz, Z; Tsuchikawa, S; Nader, J; Groves, K

JOURNAL OF NEAR INFRARED SPECTROSCOPY 24 巻 ( 6 ) 頁： 571 - 585 2016年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Near Infrared Spectroscopy

We used the Kubelka-Munk theory equations for calculating the absorption coefficient (Kλ), the scattering coefficient (Sλ), the transport absorption (σλa), the reduced scattering coefficient [σλs(1 - g)] and the penetration depth (δλ) from visible-near infrared reflectance spectra acquired over thin samples of quaking aspen and black spruce conditioned at three different moisture levels. The computed absorption and scattering coefficients varied from 0.1 mm-1 to 4.0 mm-1 and from 5.5 mm-1 to 10.0 mm-1, respectively. The absorption coefficients varied according to the absorption band, but the scattering coefficients decreased slowly towards high wavelengths. The sample moisture content was then estimated using the partial least squares (PLS) regression method from the Kλ and/or Sλ spectra, and the resulting PLS models were compared to those obtained with raw and transformed [multiplicative scatter corrected (MSC), first and second derivative] absorption spectra. The best PLS models for black spruce, quaking aspen and both species were obtained when only the 800-1800 nm range was used with the raw or MSC spectra. They led to a root mean square error of cross validation (RMSECV) of 1.40%, 1.09% and 1.23%, respectively, and to a coefficient of determination (RCV2) higher than 0.94. We also found that the Kλ spectra between 800 nm and 1800 nm can provide PLS models having an acceptable accuracy for moisture content estimation (RCV2 = 0.83 and RMSECV = 2.32%), regardless of the species.

DOI： 10.1255/jnirs.1174

Web of Science

Scopus

Optical properties of drying wood studied by time-resolved near-infrared spectroscopy 査読有り

Konagaya Keiji, Inagaki Tetsuya, Kitamura Ryunosuke, Tsuchikawa Satoru

OPTICS EXPRESS 24 巻 ( 9 ) 頁： 9561 - 9573 2016年5月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Optics Express

We measured the optical properties of drying wood with the moisture contents ranging from 10% to 200%. By using time-resolved near-infrared spectroscopy, the reduced scattering coefficient μs′ and absorption coefficient μa were determined independent of each other, providing information on the chemical and structural changes, respectively, of wood on the nanometer scale. Scattering from dry pores dominated, which allowed us to determine the drying process of large pores during the period of constant drying rate, and the drying process of smaller pores during the period of decreasing drying rate. The surface layer and interior of the wood exhibit different moisture states, which affect the scattering properties of the wood.

DOI： 10.1364/OE.24.009561

Web of Science

Scopus

PubMed

NIR spectral-kinetic analysis for thermally degraded Sugi (<i>Cryptomeria japonica</i>) wood 査読有り

Inagaki, T; Matsuo, M; Tsuchikawa, S

APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING 122 巻 ( 3 ) 2016年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Applied Physics A: Materials Science and Processing

Kinetic analysis was conducted on principal component scores calculated from second-derivative near-infrared (NIR) spectra of thermally treated Sugi (Cryptomeria japonica) wood samples. NIR reflectance spectra were measured for wood samples thermally treated at 90, 120, 150 and 180 °C in an air-circulating oven for periods ranging from 5 min to approximately 1.4 years. The Arrhenius approach, which involves the time–temperature superposition method, is used to understand the change in the principal component score. The master curve corresponded well with the change in principal component scores at each temperature and yielded a determination coefficient between the measured and estimated data of 0.99 for second principal component score. This report shows that kinetic analysis is useful to understand changes in the principal component score calculated from NIR spectra of wood subjected to thermal treatment.

DOI： 10.1007/s00339-016-9763-x

Web of Science

Scopus

Determination of true optical absorption and scattering coefficient of wooden cell wall substance by time-of-flight near infrared spectroscopy 査読有り

Kitamura Ryunosuke, Inagaki Tetsuya, Tsuchikawa Satoru

OPTICS EXPRESS 24 巻 ( 4 ) 頁： 3999 - 4009 2016年2月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Optics Express

The true absorption coefficient (μa) and reduced scattering coefficient (μ′s) of the cell wall substance in Douglas fir were determined using time-of-flight near infrared spectroscopy. Samples were saturated with hexane, toluene or quinolone to minimize the multiple reflections of light on the boundary between pore-cell wall substance in wood. μ′s exhibited its minimum value when the wood was saturated with toluene because the refractive index of toluene is close to that of the wood cell wall substance. The optical parameters of the wood cell wall substance calculated were μa = 0.030 mm-1 and μ′s = 18.4 mm-1. Monte Carlo simulations using these values were in good agreement with the measured time-resolved transmittance profiles.

DOI： 10.1364/OE.24.003999

Web of Science

Scopus

PubMed

NIR Spectral-kinetic analysis for thermally degraded Sugi (Cryptomeria japonica) wood 査読有り

Inagaki T, Matsuo M, Tsuchikawa S

Applied Physics A 122 巻頁： 208 2016年2月

Three-fibre-based diffuse reflectance spectroscopy for estimation of total solid content in natural rubber latex 査読有り

Inagaki Tetsuya, Nozawa Daisuke, Shimomura Yoshiaki, Tsuchikawa Satoru

JOURNAL OF NEAR INFRARED SPECTROSCOPY 24 巻 ( 4 ) 頁： 327 - 335 2016年

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Near Infrared Spectroscopy

It is shown that three-fibre-based diffuse reflectance spectroscopy, based on spatially resolved near infrared spectroscopy in the wavelength range 850-1060 nm, is a promising method for the measurement of quality in natural rubber latex samples. Absorbance ratios were defined as the ratio of light intensity detected at distances r and r + D from the emitter fibre. A relative absorbance ratio g was then calculated using the absorbance ratios at three wavelengths. Parameter g had a strong linear correlation with total solid content in latex (range 0.3-0.6 g g-1) with a coefficient of determination value of 0.98 and root mean square error for total solid content of 0.014 g g-1. Although the near infrared spectra measured by conventional transmission or reflectance spectroscopy were highly affected by the scattering coefficient in the sample, simulation results in this study showed that the effects of scattering in the samples on g can be reduced.

DOI： 10.1255/jnirs.1227

Web of Science

Scopus

Three fiber-based diffuse reflectance spectroscopy for estimation of total solid content in natural rubber latex

Inagaki, T, Nozawa, D, Shimomura, Y, Tsuchikawa S

Journal of Near Infrared Spectroscopy 24 巻頁： 327-335 2016年

Determination of true optical absorption and scattering coefficient of wooden cell wall substance by time-of-flight near infrared spectroscopy 査読有り

Kitamura, R.; Inagaki, T.; Tsuchikawa, S.

Optic Express 24 巻 ( 4 ) 頁： 3999-4009 2016年

Optical properties of drying wood studied by time-resolved near-infrared spectroscopy 査読有り

Konagaya, K.; Inagaki, T.; Kitamura, R.; Tsuchikawa, S.

Optic Express 24 巻 ( 9 ) 頁： 9561-9573 2016年

Nondestructive inspection of insects in chocolate using near infrared multispectral imaging 査読有り

Ma, T.; Kobori, H.; Katayama, N.; Tsuchikawa, S.

Journal of Near Infrared Spectroscopy 24 巻頁： 391-397 2016年

Three fiber-based diffuse reflectance spectroscopy for estimation of total solid content in natural rubber latex 査読有り

Inagaki, T.; Nozawa, D.; Shimomura, Y.; Tsuchikawa S.

Journal of Near Infrared Spectroscopy 24 巻頁： 327-335 2016年

近赤外分光法を用いた紙中の木材パルプの複合的評価手法の開発査読有り

河部千香、深沢博之、稲垣哲也、土川覚

紙パ技協誌 71 巻 ( 3 ) 頁： 318-325 2016年

Determination of true optical absorption and scattering coefficient of wooden cell wall substance by time-of-flight near infrared spectroscopy

Kitamura, R, Inagaki, T, Tsuchikawa, S

Optic Express 24 巻 ( 4 ) 頁： 3999-4009 2016年

Non-destructive inspection of insects in chocolate using near infrared multispectral imaging 査読有り

Ma, T; Kobori, H; Katayama, N; Tsuchikawa, S

JOURNAL OF NEAR INFRARED SPECTROSCOPY 24 巻 ( 4 ) 頁： 391 - 397 2016年

担当区分：責任著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Near Infrared Spectroscopy

Foreign matters in food products strongly affect the commercial viability of food production companies. To monitor and improve the reliability of food production processes, fast and non-destructive online inspection methods are urgently required. In this study, we exploited the high transmittance of near infrared (NIR) light, and designed an NIR transmission-type imaging device that detects lowdensity foreign matters (such as insects) inside chocolate. Insect parts had consistently lower transmittance than chocolate parts. To enhance the important differences between the two parts, the images were processed using principal component analysis. Furthermore, an algorithm for detecting the insect parts was developed in conjunction with image threshold processing and Laplacian of Gaussian edge detection. A favourable detection rate (93%) was achieved using spectral regions 840-870 nm, 870-900 nm and 900-930 nm. The results suggested that NIR multispectral imaging is useful for detecting low-density matter (insects) in the chocolate manufacturing industry.

DOI： 10.1255/jnirs.1237

Web of Science

Scopus

Optical properties of drying wood studied by time-resolved near-infrared spectroscopy

Konagaya, K, Inagaki, T, Kitamura, R, Tsuchikawa, S

Optic Express 24 巻 ( 9 ) 頁： 9561-9573 2016年

近赤外分光法を用いた紙中の木材パルプの複合的評価手法の開発査読有り

河部千香, 深沢博之, 稲垣哲也, 土川覚

紙パ技協誌 71 巻 ( 3 ) 頁： 318-325 2016年

異分野との接点が生み出す新学問

土川覚

学術の動向 21 巻 ( 2 ) 頁： 2_66 - 2_71 2016年

Combined effects of UV light and elevated temperatures on wood discolouration 査読有り

Tolvaj Laszlo, Tsuchikawa Satoru, Inagaki Tetsuya, Varga Denes

WOOD SCIENCE AND TECHNOLOGY 49 巻 ( 6 ) 頁： 1225 - 1237 2015年11月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：Wood Science and Technology

Two conifers and two deciduous wood species were irradiated by strong UV emitter mercury lamp at elevated temperatures up to 160 °C. Other series of samples were treated in the same chamber at the same temperatures but without light. Results showed that UV light irradiation produced much greater discolouration at elevated temperatures above 80 °C than at ambient temperature. The combined light irradiation and thermal treatment at 160 °C generated much larger discolouration than the sum of the discolouration data caused by UV light irradiation at 30 °C and by pure thermal treatment at 160 °C. The thermal effect during photodegradation was not only the simple addition of two effects, but the elevated temperature multiplied the effect of photodegradation. The greatest difference was shown by the redness change. The Arrhenius plots of all tree colour coordinates had a breaking point close to 100 °C, showing that above this temperature the chemical changes are more complex than below this value.

DOI： 10.1007/s00226-015-0749-1

Web of Science

Scopus

NIR spectroscopic evaluation of nitrogen and carbon content in Japanese Mustard Spinach (Brassica rapa var. perviridis) 査読有り

Inagaki T., Minagawa C., Yokochi H., Tsuchikawa S.

2015 54th Annual Conference of the Society of Instrument and Control Engineers of Japan, SICE 2015 頁： 97 - 99 2015年9月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：2015 54th Annual Conference of the Society of Instrument and Control Engineers of Japan, SICE 2015

Demonstration of prediction of carbon and nitrogen content in Japanese Mustard Spinach (Brassica rapa var. perviridis) was accomplished using near infrared (NIR) reflectance spectroscopy. NIR reflectance spectroscopic measurement of hydroponically cultivated fresh leaves growing on stalks were taken at some growing phase. Calibrations were developed for carbon and nitrogen content in leaves using partial least square (PLS) regression method. Strong correlation between measured and predicted value for carbon and nitrogen were observed.

DOI： 10.1109/SICE.2015.7285393

Scopus

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