共查询到20条相似文献,搜索用时 15 毫秒
1.
Determination of quality parameters such as lignin and extractive content of wood samples by wet chemistry analyses takes
a long time. Near-infrared (NIR) spectroscopy coupled with multivariate calibration offers a fast and nondestructive alternative
to obtain reliable results. However, due to the complexity of the NIR spectra, some wavelength selection is generally required
to improve the predictive ability of multivariate calibration methods. Pinus brutia Ten. is the most growing pine species in Turkey. Its rotation period is around 80 years; the forest products industry has
widely accepted the use of Pinus brutia Ten. because of its ability to grow on a wide range of sites and its suitability to produce desirable products. Pinus brutia Ten. is widely used in construction, window door panel, floor covering, etc. Determination of lignin and extractive content
of wood provides information to tree breeders on when to cut and how much chemicals are needed for the pulping and bleaching
process. In this study, 58 samples of Pinus brutia Ten. trees were collected in Isparta region of Turkey, and their lignin and extractive content were determined with standard
reference (TAPPI) methods. Then, the same samples were scanned with near-infrared spectrometer between 1,000 and 2,500 nm
in diffuse reflectance mode, and multivariate calibration models were built with genetic inverse least squares method for
both lignin and extractive content using the concentration information obtained from wet standard reference method. Overall,
standard error of calibration (SEC) and standard error of prediction (SEP) ranged between 0.35% (w/w) and 2.40% (w/w). 相似文献
2.
Anupun Terdwongworakul Vittaya Punsuwan Warunee Thanapase Satoru Tsuchikawa 《Journal of Wood Science》2005,51(2):167-171
Near-infrared (NIR) spectroscopy has been demonstrated as a means for rapid nondestructive determination of the chemical composition and final pulp yield of Eucalyptus camaldulensis in Thailand tree plantations. Multiple linear regression (MLR) analysis and partial least squares (PLS) analysis were introduced to develop statistical models in terms of calibration equations for total pulp yield, screened pulp yield, and contents of -cellulose, pentosans, and lignin in wood. In MLR analysis, a reasonably good calibration equation was found only for pentosans (standard error of prediction (SEP): 0.98%). The PLS analysis improved the accuracy of prediction for every criterion variable, especially for pentosans (SEP: 0.91%) and lignin (SEP: 0.52%). Also, in the case of screened pulp yield, we were able to use such a statistical result as an indicator of the characteristics of the pulp and paper. Thus, NIR spectroscopy could be satisfactorily used as an effective assessment technique for Eucalyptus camaldulensis plantation trees. 相似文献
3.
Laszlo Horvath Ilona Peszlen Perry Peralta Steve Kelley 《Wood Science and Technology》2011,45(2):303-314
The investigation of genetically modified trees requires rapid and reliable techniques to measure the mechanical properties
at an early age in order to give timely feedback to forest geneticists. In this study, transmittance near-infrared (NIR) spectroscopy
was used to predict the green mechanical properties of 1- and 2-year-old transgenic and wild-type aspen. Green modulus of
elasticity (MOE) in three-point bending and green ultimate compression strength (UCS) parallel to the grain were predicted
from the NIR spectra of dry wood meal pellets. Green UCS had strong correlation (R
2 = 0.91) and green MOE had good correlation (R
2 = 0.78) with the spectra. The latter could be explained by the moderate correlation of MOE with the lignin content of the
transgenic samples, suggesting that besides chemical composition MOE also depends on anatomical properties. The ratio of performance
to deviation value suggested that the calibration model of both UCS (2.94) and MOE (1.91) could be used for screening. 相似文献
4.
Takanori Imai Sousuke Inoue Naomi Ohdaira Yasuyuki Matsushita Rie Suzuki Mariko Sakurai José Manoel Henriques de Jesus Salete Kiyoka Ozaki Zenesio Finger Kazuhiko Fukushima 《Journal of Wood Science》2008,54(6):470-475
Heartwood extracts from Amazonian trees cumaru-ferro (Dipteryx odorata), jatoba (Hymenaea courbaril), and guarita (Astronium lecointei) exhibit antioxidant activities comparable with that of α-tocopherol, a well-known antioxidant. This article reports the characterization of the antioxidant compounds in the extracts
of the three heartwoods. Silica gel column chromatography of the cumaru-ferro EtOAc extract yielded (−)-(3R)-7,2′,3′-trihydroxy-4′-methoxyisoflavan and (+)-(3R)-8,2′,3′-trihydroxy-7,4′-dimethoxyisoflavan. Silica gel column chromatography followed by preparative high-performance liquid
chromatography of the jatoba EtOAc extract yielded (−)-fisetinidol and (+)-trans-taxifolin. Chemical structures were assigned using electron-ionization mass spectrometry, 1H and 13C nuclear magnetic resonance (NMR) spectroscopy including nuclear Overhauser effect spectroscopy (NOESY), as well as optical
rotation and circular dichroism. Gas chromatography-mass spectrometry demonstrated that the isolated compounds were predominant
in the EtOAc extracts. In the guarita EtOAc extract, catechin and gallic acid were identified by comparing their retention
times and mass fragmentation patterns with those of authentic samples. Antioxidant activity determined by the 1,1-diphenyl-2-picrylhydrazyl
assay demonstrated that all these compounds had activities comparable with that of α-tocopherol.
Part of this report was presented at the 57th Annual Meeting of the Japan Wood Research Society, Hiroshima, August 2007 相似文献
5.
P. D. Jones L. R. Schimleck G. F. Peter R. F. Daniels A. Clark III 《Wood Science and Technology》2005,39(7):529-545
Tracheid coarseness, specific surface, wall thickness, perimeter, and radial and tangential diameter from 119 radial strips
of Pinus taeda L. (loblolly pine) trees grown on 14 sites in three physiographic regions of Georgia (USA) were measured by SilviScan. NIR
spectra were also collected in 10 mm increments from the radial longitudinal surface of each strip and split into calibration
(9 sites, 729 spectra) and prediction sets (6 sites, 225 spectra). NIR spectra (untreated and mathematically treated first
and second derivative and multiplicative scatter correction) were correlated with tracheid properties to develop calibrations
for the estimation of these properties. Strong correlations were obtained for properties related to density, the strongest
R
2 being 0.80 (coarseness), 0.78 (specific surface) and 0.84 (wall thickness). When applied to the test set, good relationships
were obtained for the density-related properties (R
p
2 ranged from 0.68 to 0.86), but the accuracy of predictions varied depending on math treatment. The addition of a small number
of cores from the prediction set (one core per new site) to the calibration set improved the accuracy of predictions and,
importantly, minimized the differences obtained with the various math treatments. These results suggest that density related
properties can be estimated by NIR with sufficient accuracy to be used in operational settings. 相似文献
6.
Benny Green P. David Jones Darrel D. Nicholas Laurence R. Schimleck Rubin Shmulsky 《Wood Science and Technology》2011,45(3):583-595
The use of calibrated near infrared (NIR) spectroscopy for measuring and predicting the advancement of wood decay in Pinus spp. sapwood wafers that were subjected to Gloeophyllum trabeum for periods ranging from 1 to 10 days was investigated. NIR spectra were obtained from the center of the cross-sectional
face of each sample before and after decay tests. Mass loss and compression tests were also used to measure the progression
of decay. Calibrations were created from NIR spectra, mass loss, and compression strength data using untreated and mathematically
treated (multiplicative scatter correction and first and second derivative) spectra. Strong relationships were derived from
the calibrations with the strongest R
2 values being 0.98 (mass loss) and 0.97 (compression strength). Calibrations for mass loss showed the strongest statistics
for predicting wood decay of a separate test set (0.85 raw, second derivative to 0.76 multiplicative scatter correction (MSC),
while predictions for compression strength of the decayed samples resulted in R
2 of 0.69 (raw) to 0.54 (MSC). Calibrations created from the amount of time the samples were decayed showed strong statistics,
indicating that NIR spectroscopy can predict the early stages of wood decay. 相似文献
7.
Five Populus x euramericana wood samples representing three different sites were selected and nearinfrared (NIR) spectra were obtained. For these sections, basis weight, brightness and three mechanical properties (tensile index, tearing index and bursting index) were determined by standard analytical methods. Calibrations were developed for each paper property using the NIR spectra, data on paper properties, using partial least squares (PLS) regression. The results show that the coefficients of correlation of calibration and validation for basis weight were 0.8824 and 0.8299, respectively; the standard error of calibration (SEC) and prediction (SEP) were 1.150 and 1.170, respectively. In testing for brightness, the correlation coefficient of calibration was 0.9621 and for validation 0.9612, while the SEC and SEP were 0.997 and 1.300, respectively; paper brightness and NIR spectroscopy were highly correlated. NIR spectroscopy can be used to predict tensile, tearing and bursting indices of paper samples rapidly. We found that the paper properties fitted by NIR and GB methods were highly correlated. The coefficients of correlation of calibration and validation for basis weight exceeded 0.8000, while the SEC and SEP were very small. These results reveal that the five paper properties of Populus x euramericana and those predicted by the NIR model were highly correlated. We conclude that the NIR models can be used for the prediction of paper properties. 相似文献
8.
Huaqiang Yu Rongjun Zhao Feng Fu Benhua Fei Zehui Jiang 《Frontiers of Forestry in China》2009,4(3):368-373
Mechanical properties and the visible and near infrared (NIR) (350–2500 nm) spectra obtained from longitudinal and transverse
face of 155 small clear wood samples of Chinese fir (Cunninghamia lanceolata) were measured, and 103 of them were used to establish calibration models. Calibrations were tested on an independent set
(52 samples). Differences between calibrations developed by using the longitudinal and transverse face were small. The calibrations
developed by using NIR spectra (350–2500 nm) collected from transverse face were slightly inferior to those developed by using
NIR spectra collected from longitudinal face. When reducing the spectral range to between 780 and 1050 nm, the calibrations
developed by using NIR spectra collected from longitudinal face were slightly inferior to those developed by using NIR spectra
collected from transverse face, and reducing the spectral range causes no decrease in the quality of the models developed
using NIR spectra collected from transverse face. Partial lease square (PLS) modeling and test showed that calibrations developed
using the visible and NIR spectra from transverse and longitudinal faces and calibrations developed by using the reducing
spectral range (780–1050 nm) from the transverse face were moderate, and have a RPD range from 1.51 to 1.90. It is concluded
that NIR spectroscopy can be used as an initial screening.
__________
Translated from Journal of Northwest Forestry University, 2007, 22(5): 149–154 [译自: 西北林学院学报] 相似文献
9.
Takaaki Fujimoto Yohei Kurata Kazushige Matsumoto Satoru Tsuchikawa 《Journal of Wood Science》2010,56(6):452-459
Near-infrared (NIR) spectroscopy coupled with multivariate analysis was applied to estimate multiple traits of sawn lumber.
The effects of the lumber conveying speed (LCS) and measurement resolution of spectra (MRS) on the calibrations were examined.
NIR spectra ranging from 1300 to 2300 nm were acquired at LCSs of 10, 20, and 30 m/min and at MRSs of 2, 4, and 16 nm. Prediction
models of bending strength (F
b), modulus of elasticity in bending tests (E
b), dynamic modulus of elasticity (E
fr), and wood density (DEN) were developed using partial least-squares (PLS) analysis. LCS and MRS did not significantly influence
the calibration performance for any wood property. The regression coefficients also showed no clear differences for any of
the conditions. This indicates that the important explanatory variables included in the models are not greatly influenced
by these measurement conditions. PLS2 analysis results, when presented graphically, allowed easy interpretation of the relationships
between wood mechanical properties and chemical components, e.g., bending strength and stiffness were mainly related to polysaccharides
cellulose and hemicellulose. NIR spectroscopy has considerable potential for online grading of sawn lumber, despite the harsh
measurement conditions. 相似文献
10.
Fungal species were recorded from Populus tremula leaves, twigs and bark (trunk) at eight sites in the northern region of Spain, with the aim of evaluating the effect of sampling site, sampling tissue and isolation method on the frequency and species distribution of the fungi recovered from necrotic and healthy tissues. Two different isolation methods were used: the first consisted of finding fruitbodies on plant tissues after incubating them in wet and warm conditions, and the second included growing mycelia from plant fragments plated on potato dextrose agar (PDA). A total of 48 fungal species were isolated from 960 plant fragments. Cytospora chrysosperma, previously reported to be a pathogen of poplar, was recovered very frequently and was recorded as much in healthy as in dead or dying tissues. Cladosporium maculicola, Elsinoe veneta, Alternaria alternata, Aureobasidium pullulans and Pollaccia radiosa were also frequently isolated. The isolation frequencies from necrotic and healthy plant tissues were significantly different between sites and isolation methods. The incubation in moist chambers revealed significantly more fungal isolates and a higher species richness (38 species) than isolations on PDA. However, 16% of the fungal species were exclusively recorded from cultures. Therefore, a combination of several isolation methods is recommended for surveys of fungal communities associated with trees. 相似文献
11.
《Southern Forests》2013,75(3-4):181-189
Near-infrared (NIR) scanning technology is regarded as a potential tool for rapid determination of wood properties, which can substitute time-consuming and costly traditional methods. Pinus patula is the most important softwood species in South Africa, and this study is aimed at developing NIR calibration models for quick prediction of its pulp yield and chemical composition. A total of 85 trees from 17 plots, covering the range of site conditions in the Mpumalanga escarpment area, were sampled. Two samples were taken from each tree: a 1 m billet above breast height and a 20 mm disc at breast height. The billet was pulped using the kraft pulping process to determine pulp yield. The disc was ground into sawdust and the chemical composition was determined using conventional wet chemistry. Sawdust was scanned on a NIR spectrophotometer to produce NIR spectra. Calibration models to predict pulp yield, cellulose and lignin content were developed by applying chemometrics and partial least squares regression. Validation and determination of prediction accuracy of the models were performed using independent data. The prediction of cellulose and lignin were acceptable with correlations of determinations (r 2) of 0.71 and 0.70 respectively. Standard errors of prediction were generally low (less that 0.86) for all the models. The prediction r 2 for both total and screened pulp yield were only 0.62. Although the cellulose and lignin models can be used with confidence, the expansion of the sample size for follow-up research must be considered in order to increase the variability of tested wood properties and improve the prediction strength of the models. The NIR calibration provided in this study can contribute to the efficient examination of forest site-to-wood quality relationships that would enhance precision forest management and wood processing efficiency. 相似文献
12.
Ozone pollution was analyzed in arolla pine (Pinus cembra L.) forests growing over two mountain ranges located in southern France by using specific ozone-sensitive tobacco plants as bio-indicators and a physico-chemical analyzer. Concentrations of abscisic acid (ABA) were determined in needles of healthy and declining trees in a massif with a declining forest and in a massif with a healthier forest. In addition, ABA was quantified in needles of trees exposed to either charcoal-filtered air or unfiltered air supplemented with ozone in open-top chambers located at the Col du Donon. The concentration of ABA in needles of injured trees increased when the trees were exposed to ozone either under field conditions or in open-top chambers; however, the difference in ABA concentration between control and ozone-exposed needles was less in the open-top chambers, where ozone was the sole variable, than in the field. The results are discussed in the context of the effects of ozone on plant water relations and hormone-mediated cell defense. 相似文献
13.
Crystallinity is an important property of woody materials; it responds to tree growth traits, structure, and chemical composition,
and has a significant effect on Young’s modulus, dimensional stability, density, and hardness, etc. The ability of near-infrared
(NIR) spectroscopy coupled with multivariate analysis to rapidly predict the crystallinity of slash pine (Pinus elliotii) plantation wood was investigated. The results showed that the NIR data could be correlated with the X-ray diffraction (XRD)-determined
crystallinity of slash pine wood by use of partial least squares (PLS) regression, producing excellent coefficients of determination,
r
2, and root mean square error of calibration, RMSEC. The use of either reduced spectral ranges or the selection of certain
wavelengths consistent with known chemical absorptions did not have any detrimental effect on the quality of PLS models allowing
the use of inexpensive, small, and portable spectrometers. These studies show that NIR spectroscopy can be used to rapidly
predict the crystallinity of slash pine wood. 相似文献
14.
Ken Watanabe Isao Kobayashi Naohiro Kuroda Masaki Harada Shuichi Noshiro 《Journal of Wood Science》2012,58(5):383-390
We propose a non-destructive method to predict the oven-dry density of Sugi (Cryptomeria japonica D. Don) using near infrared (NIR) spectroscopy so as to calibrate a commercial moisture meter. A prediction model for oven-dry density was developed using NIR spectra obtained from Sugi samples with a known density. The density of air-dried Sugi boards was predicted with the developed model. Then, the moisture content (MC) of the boards was measured by a hand-held capacitance-type and an in-line microwave moisture meters. For each board, the moisture meters were calibrated by the predicted density. The predicted density was correlated with the measured one with an R 2 of 0.81 and a standard error of prediction (SEP) of 15.3 kg/m3 within the measured density of 279.2–436.4 kg/m3, indicating that the developed model was applicable for predicting oven-dry density of Sugi. The MC readings of both moisture meters showed a good correlation with the oven-dry MC that ranged from 12.1 to 28.9 %. For both moisture meters, the density calibration with the NIR-predicted density gave a higher R 2 and a lower SEP than with the conventional calibration with the mean density. These results demonstrate that the present density calibration using NIR spectroscopy could improve the performance of the moisture meters for the air-dried Sugi boards with varying densities. 相似文献
15.
Stig Lande Sander van Riel Olav Albert Høibø Marc Henry Schneider 《Wood Science and Technology》2010,44(2):189-203
The use of furfuryl alcohol (FA) as a wood modification agent has been known for decades. An independent and reliable analytical
method to determine the level of furfurylation is not available. This article reports the use of near infrared spectroscopy
(NIR) and thermogravimetric analysis (TGA) to make partial least square prediction models for determining the furfurylation
level (the percentage of FA polymer formed within the wood structure). A total of 115 individual samples of furfurylated Scots
pine (Pinus sylvestris) originating from 115 production batches were used for modelling. As much as 81 samples were randomly selected for the calibration
set and 34 samples for the validation set. Both NIR and TGA gave good predictions when validated by a separate test set. The
r
2 for NIR and TGA are 0.93 and 0.94, respectively, and the root mean square errors of predictions are 1.025 and 0.958, respectively.
However, the number of principal components for the NIR and TGA models is two and six, respectively. The NIR method is preferred
because only two principal components are used and sampling is fast. 相似文献
16.
Xiping Zhao Pingping Guo Lixia Hu Bin Hui Qingzheng Cheng Brian K. Via 《Scandinavian Journal of Forest Research》2018,33(8):729-734
Despite the importance of starch for tree growth, methodological challenges in starch analysis slow down the research on its ecological importance. In this study, a rapid monitoring method was developed for measuring starch content in Pinus taeda L. seedlings after cold treatments. A linear mixed-effects model was used to analyze the effects of cold treatments, seedling tissue types and their interaction on starch content. Mid-infrared (MIR) and near-infrared (NIR) spectra were surveyed, and the results were analyzed using partial least squares regression to determine the starch content. The determination coefficient for calibration and residual predictive deviation were compared between MIR and NIR models to assess the variability of the established models. The results showed that the effects of cold treatments, seedling tissue types and their interaction on starch content were significant. Compared to MIR spectra, NIR spectra is more suitable to estimate starch content in the seedlings. Using NIR spectra, roots provided the most accurate estimates of starch content. The presented guidelines regarding data accuracy as a function of MIR/NIR spectra of samples represent an important methodological reference for starch quantification, which will improve the understanding of the fundamental role of starch in seedlings against environmental forces. 相似文献
17.
Summary The aim of the present study was to investigate whether the resistance of beech foliage(Fagus sylvatica) against oxidative stress was affected by soil quality, nitrogen or CO2 fertilisation, or lachnid infestation(Phyllaphis fagi). For this purpose young beech trees were grown for four years in reconstructed calcareous or acidic forest soils in open
top chambers under ambient or elevated CO2 concentrations with two levels of nitrogen fertilisation. At harvest lachnid colonisation was observed, preferentially on
leaves from trees in calcareous soil and on leaves from trees fertilised with the high nitrogen level. General leaf characteristics
such as pigment concentrations, dry mass, and leaf mass ber area were not affected by the soil type, nitrogen fertilisation
or CO2 regime. Leaves colonised with lachnids displayed slightly increased leaf mass per area. When the stress resistance was challenged
by exposure to paraquat — a herbicide inducing oxidative stress — leaves from trees grown on calcareous soil maintained significantly
longer membrane integrity and, thus, were better protected against stress than leaves from trees on acidic soil. Other experimental
variables had negligible or no effects on the resistance against oxidative stress.
相似文献
18.
P. David Jones Laurence R. Schimleck Richard F. Daniels Alexander Clark III Robert C. Purnell 《Wood Science and Technology》2008,42(5):385-400
A necessary objective for tree-breeding programs, with a focus on wood quality, is the measurement of wood properties on a
whole-tree basis, however, the time and cost involved limits the numbers of trees sampled. Near infrared (NIR) spectroscopy
provides an alternative and recently, it has been demonstrated that calibrations based on milled increment cores and whole-tree
data can provide good estimates of whole-tree properties. Several options exist for sampling standing trees and the aim of
this study was to compare wood property calibrations based on NIR spectra collected from samples obtained using different
sampling methods. Calibrations for whole-tree lignin and basic specific gravity based on NIR spectra from whole-tree chips
(milled or intact) had the strongest statistics, calibrations based on NIR spectra from milled increment cores were similar.
Other options for sampling the tree (drill shavings, etc.) gave errors that were too large for practical applications. If
an increment core is going to be used to estimate whole-tree properties, it is recommended that it be dried and milled prior
to analysis. 相似文献
19.
Eucalyptus calophylla Lindley exposed to two levels of sulfur dioxide continuously for 120 days in open top chambers, showed contrasting changes in resource partitioning. Exposure to 125 μg m?3 of SO2 had an apparent fertilization effect with increase in the weight of stems and total above ground plant weight whereas 261 μg m?3 had a toxic effect with a reduction in the total number of leaves. SO2 had no effect on leaf protein or chlorophyll concentration nor on visible injury. 相似文献
20.
Endophytic fungi in leaves and twigs of healthy and diseased beech trees (Fagus sylvatica L.). Endophytic fungi were isolated from surface-sterilized leaves and twigs of healthy and diseased trees. Three fungal species could be isolated frequently: Apiognomonia errabunda, Diaporthe eres and Bisporella sp. D. eres occurred in leaves of healthy trees more frequently, than in those of diseased trees. It has been hypothesized, that less capacity of water and nutrient uptake of diseased trees is responsible for this effect. A mutualistic symbiosis of A. errabunda and D. eres with beech trees is supposed and discussed. 相似文献