研究者詳細 - 土川　覚

論文 - 土川　覚

分割表示 539 件中 141 - 160 件目／全件表示 >>

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

A review of recent application of near infrared spectroscopy to wood science and technology 査読有り

Tsuchikawa Satoru, Kobori Hikaru

JOURNAL OF WOOD SCIENCE 61 巻 ( 3 ) 頁： 213 - 220 2015年6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：Journal of Wood Science

This review article introduces recent scientific and technical reports due to near infrared spectroscopy (NIRS) at wood science and technology, most of which was published between 2006 and 2013. Many researchers reported that NIR technique was useful to detect multi traits of chemical, physical, mechanical and anatomical properties of wood materials although it was widely used in a state where characteristic cellular structure was retained. However, we should be sensitive and careful for application of NIRS, when spectra coupled with chemometrics presents unexpected good results (especially, for mechanical physical and anatomical properties). The real application for on-line or at-line monitoring in wood industry is desired as next step. Basic spectroscopic research for wooden material is also progressed. It should be a powerful and meaningful analytical spectroscopic tool.

DOI： 10.1007/s10086-015-1467-x

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Scopus

Visualisation of spatial distribution of moisture content and basic density using near-infrared hyperspectral imaging method in sugi (Cryptomeria japonica)

Fujimoto T., Numa T., Kobori H., Tsuchikawa S.

International Wood Products Journal 6 巻 ( 2 ) 頁： 46 - 48 2015年5月

担当区分：最終著者記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：International Wood Products Journal

This study quantified the spatial distribution of moisture content and basic density within Cryptomeria japonica branches using near-infrared (NIR) hyperspectral imaging and multivariate data analysis techniques. The hyperspectral data for wood disk samples were acquired using a Compovision NIR Composition Imaging System (Sumitomo Electric Industries, Ltd., Yokohama, Japan) with a spectral range of 913-2519 nm. The calibration models for prediction of moisture content and basic density were developed using partial least squares (PLS) regression analysis. The PLS model for moisture content and basic density showed good predictive performance with coefficients of determination 0.82 (RMSEP512.4%) and 0.84 (RMSEP528.0 kg m-3) respectively. The spatial distribution of predicted moisture content clearly detected the low moisture white zone surrounding the heartwood. The high density compression wood could be also visualised with the NIR hyperspectral imaging technique. The results presented here provide useful information for development of a novel log sorting method.

DOI： 10.1179/2042645314Y.0000000084

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Scopus

Fast online NIR technique to predict MOE and moisture content of sawn lumber 査読有り

Kobori, H; Inagaki, T; Fujimoto, T; Okura, T; Tsuchikawa, S

HOLZFORSCHUNG 69 巻 ( 3 ) 頁： 329 - 335 2015年4月

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：Holzforschung

A fast online grading apparatus for sawn lumber based on near-infrared (NIR) spectroscopy has been developed. The method is based on a novel wavelength dispersive NIR spectrophotometer equipped with a diffraction grating linear sensor and high-intensity lighting. It was possible to acquire spectra from the entire surface of Hinoki cypress lumber sections traveling on a conveyor belt at a speed of 120 m min-1. Additionally, predictive models for moisture content (MC) and modulus of elasticity (MOE) under various MC conditions were developed from the NIR spectra with the aid of partial least squares regression (PLSR) analysis. Both the MC and MOE predictive models demonstrated sufficient levels of prediction accuracy for use on high-speed conveyor belts, and the results of various experiments indicate that the developed device could be applied for the online quality certification of sawn lumber in commercial sawmills.

DOI： 10.1515/hf-2014-0021

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Scopus

Construction of a novel densitometer that utilizes a near-infrared laser system with Douglas fir (Pseudotsuga menziesii) 査読有り

Kitamura R., Tsuchikawa S.

Wood Material Science and Engineering 10 巻 ( 1 ) 頁： 69 - 74 2015年1月

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：Wood Material Science and Engineering

A novel densitometer consisting of a continuous wave near-infrared (NIR) laser source and an avalanche photodiode module as the detector has been designed, which can rapidly and non-destructively measure the density of wood. The wood density of a small area (3.14 mm2) at the radial-transverse face was continuously estimated using the intensity of the transmitted light with the aid of the modified Lambert-Beer law. By conducting a validity evaluation with statistical coefficients, it was shown that the constructed system could obtain the sharp density profile compatible with X-ray densitometer [Root mean squared error of calibration (RMSEC) = 0.045 g cm−3, Root mean squared error of validation (RMSEV) = 0.046 g cm−3). It was concluded that the constructed NIR device has high performance from the viewpoint of operability, measuring time and safety.

DOI： 10.1080/17480272.2014.968873

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Scopus

Assessment of variations in air-dry wood density using time-of-flight near-infrared spectroscopy 査読有り

Hans G., Kitamura R., Inagaki T., Leblon B., Tsuchikawa S.

Wood Material Science and Engineering 10 巻 ( 1 ) 頁： 57 - 68 2015年1月

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：Wood Material Science and Engineering

Abstract: Non-destructive measurement of wood density using reflectance and transmittance near-infrared spectroscopy (NIRS) has already been reported by several researchers. However, these methods do not allow an independent determination of the spectral contributions of the absorption and scattering effects. In this study, time-of-flight NIRS (TOF-NIRS) was used to measure wood density of seven softwood and hardwood species. A curve fitting procedure was used to resolve the diffusion equation and compute the absorption (µ<inf>a</inf>) and reduced scattering coefficients ((Formula presented.)) from the time-resolved profiles (TRPs) acquired from the wood samples. Statistical parameters were also computed from TRPs and correlated with the wood air-dry density as well as with both optical coefficients. A simple linear regression model was built to relate air-dry wood density to µ<inf>a</inf> (R2 = 0.56, root mean square error [RMSE] = 0.047 g/cm3, p value < 0.05). Results obtained were in good agreement with the modified Beer–Lambert law for turbid media. The square root of the (Formula presented.) / (Formula presented.) ratio (which was well correlated with the photons mean path length) was used to correct for the distortion due to scattering in absorbance NIR spectra acquired using reflectance spectroscopy. This research demonstrates the potential of TOF-NIRS to assess wood density and to correct reflectance spectra for scattering effects.

DOI： 10.1080/17480272.2014.923937

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Scopus

A Review of Recent Application of Near Infrared Spectroscopy to Wood Science and Technology 招待有り査読有り

Tsuchikawa, S.; Kobori, H.

Journal of Wood Science 61 巻頁： 213-230 2015年

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

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

Journal of Near Infrared Spectroscopy 2015年

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

Tolvaj, L.; Tsuchikawa, S.; Inagaki T.; Varga, D.

Wood Science and Technology 49 巻 ( 6 ) 頁： 1225-1237 2015年

A Review of Recent Application of Near Infrared Spectroscopy to Wood Science and Technology

Tsuchikawa, S, Kobori, H

Journal of Wood Science 61 巻頁： 213-230 2015年

Combined effects of UV light and elevated temperatures on wood discolouration

Tolvaj, L, Tsuchikawa, S, Inagaki T, Varga, D

Wood Science and Technology 49 巻 ( 6 ) 頁： 1225-1237 2015年

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

Inagaki Tetsuya, Minagawa Chinatsu, Yokochi Hideyuki, Tsuchikawa Satoru

2015 54TH ANNUAL CONFERENCE OF THE SOCIETY OF INSTRUMENT AND CONTROL ENGINEERS OF JAPAN (SICE) 頁： 97 - 99 2015年

Visualisation of degree of acetylation in beechwood by near infrared hyperspectral imaging 査読有り

Inagaki, T; Mitsui, K; Tsuchikawa, S

JOURNAL OF NEAR INFRARED SPECTROSCOPY 23 巻 ( 6 ) 頁： 353 - 360 2015年

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

Spatial distributions of the degree of acetylation in cross- and radial-sectional faces of beechwood samples under vapour-phase reaction are observed using near infrared hyperspectral imaging. The near infrared second derivative amplitude at 1727 nm, which is assigned to the first overtone of the CH stretching vibration averaged over the cross section and radial section, has strong linear correlationwith the substance concentration of acetyl groups (CA) held in the cell walls. Tangentially averaged CA is well explained by the modified rate equation. Both the rate constant and hindrance to the diffusion reagent reach constant values at a depth of about 4 mm from the edge of the wood, indicating that the acetylation reaction proceeds close to a depth of 4 mm.

DOI： 10.1255/jnirs.1181

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Scopus

CiNii Research

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

Tetsuya Inagaki, Chinatsu Minagawa, Hideyuki Yokochi, Satoru Tsuchikawa

2015 54TH ANNUAL CONFERENCE OF THE SOCIETY OF INSTRUMENT AND CONTROL ENGINEERS OF JAPAN (SICE) 頁： 97 - 99 2015年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：IEEE

Web of Science

Simultaneous prediction of density and moisture content of wood by terahertz time domain spectroscopy

Inagaki, T.; Ahmed, B.; Hartley, I. D.; Tsuchikawa, S.; Reid, M.

Journal of Infrared, Millimeter, and Terahertz Waves 35 巻 ( 11 ) 頁： 949-961 2014年11月

Simultaneous prediction of density and moisture content of wood by terahertz time domain spectroscopy

Inagaki, T, Ahmed, B, Hartley, I. D, Tsuchikawa, S, Reid, M

Journal of Infrared, Millimeter, and Terahertz Waves 35 巻 ( 11 ) 頁： 949-961 2014年11月

Simultaneous prediction of density and moisture content of wood by terahertz time domain spectroscopy 査読有り

Inagaki Tetsuya, Ahmed Belal, Hartley Ian D., Tsuchikawa Satoru, Reid Matthew

JOURNAL OF INFRARED MILLIMETER AND TERAHERTZ WAVES 35 巻 ( 11 ) 頁： 949 - 961 2014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：Journal of Infrared, Millimeter, and Terahertz Waves

In this study, demonstration of simultaneous prediction of solid wood density and moisture content, both of which are critical in manufacturing operations, of 4 species (Aspen, Birch, Hemlock and Maple) was accomplished using terahertz time-domain spectroscopy (THz-TDS). THz measurements of wood at various moisture contents were taken for two orientations of the THz field (parallel and perpendicular) with respect to the visible grain. The real and imaginary parts of the dielectric function averaged over the frequency range of 0.1 to 0.2 THz had strong correlation with density and moisture content of the wood. We extend a model that has been applied previously to oven-dry wood to include the effects of moisture below the fiber saturation point by combining two effective medium models, which allows the dielectric function of water, air and oven-dry cell wall material to be modeled to give an effective dielectric function for the wood. A strong correlation between measured and predicted values for density and moisture content were observed.

DOI： 10.1007/s10762-014-0095-7

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Scopus

Prediction of oven-dry density of wood by time-domain terahertz spectroscopy 査読有り

Inagaki, T; Hartley, ID; Tsuchikawa, S; Reid, M

HOLZFORSCHUNG 68 巻 ( 1 ) 頁： 61 - 68 2014年1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：Holzforschung

Wood is relatively transparent to terahertz (THz) radiation with wavelengths in the submillimeter range. This radiation has a high potential for sensing and imaging wood with a good spatial resolution. THz is especially sensitive to moisture content, fiber alignment, and density - all of which are critical in the manufacturing of wood products. In this work, a systematic study was undertaken on 46 very different wood species by means of THz time-domain spectroscopy with density determination in focus. The dielectric response of wood was modeled based on the Maxwell-Garnett effective medium theory. The dielectric function of the cell wall material was found to be extremely consistent over this large number of species with very different properties. This renders possible to determine wood density by THz time-domain spectroscopy. A strong correlation between the measured and predicted densities has been observed for all the samples investigated. © 2014 Walter de Gruyter GmbH, Berlin/Boston.

DOI： 10.1515/hf-2013-0013

Web of Science

Scopus

Mapping of Leaf Water Content Using Near-Infrared Hyperspectral Imaging 査読有り

Higa Sakura, Kobori Hikaru, Tsuchikawa Satoru

APPLIED SPECTROSCOPY 67 巻 ( 11 ) 頁： 1302 - 1307 2013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：Applied Spectroscopy

In this study, near-infrared hyperspectral imaging was applied to predict the water content of golden pothos (Epipremnum aureum) leaves, after which partial least squares regression (PLSR) analysis was performed to predict their averaged water content. The resulting predictive model was then applied to each single-pixel spectra in order to construct a water content image that could be used to evaluate the model's applicability to the single-pixel spectra through partial least squares score comparisons between the averaged spectra used for calibration and the single-pixel spectra. In the next phase, it was determined that a rebuilt PLSR predictive model based on the averaged spectra of an applicable pixel showed higher prediction accuracy than that of the original model. This study provides effective information about the limitations of prediction mapping and the optimization of pixel selections for better calibrations. © 2013 Society for Applied Spectroscopy.

DOI： 10.1366/13-07028

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論文 - 土川 覚

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論文 - 土川　覚