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1.
Experimental determination of the convective heat and mass transfer coefficients for wood drying 总被引:1,自引:1,他引:0
The knowledge of the convective heat and mass transfer coefficients is required for the characterization of the boundary
conditions of the heat and mass transfer equations of a wood drying model based on water potential. A new experimental method
for the determination of the convective mass transfer coefficient is presented. This method is based on the measurement of
the moisture content, and indirectly the water potential, at the surface of a wood specimen at different drying times. Drying
experiments were performed on red pine (Pinus resinosa Ait.) sapwood from nearly saturated to dry conditions at 56 °C, 52% relative humidity and air velocities of 1.0, 2.5 and
5.0 m s−1. The results show that the convective mass transfer coefficient is constant until the wood surface moisture content reaches
about 80% and then decreases more or less gradually as the moisture content decreases further. The convective mass transfer
coefficient increases with air velocity. A regression analysis shows that there is no significant improvement in considering
the water potential gradient near the wood surface when the difference in water potential between the surface and the surrounding
air (ψs − ψ∞) is used to determine the convective mass flux at the surface. Also, ψs − ψ∞ is more appropriate than the water vapour pressure difference (pvs − pv∞) as the responsible driving force of the moisture flux leaving the wood surface. The convective heat transfer coefficient
was determined during the same experiments. A plateau is observed at high values of moisture content corresponding to the
constant drying rate period.
Received 27 February 1998 相似文献
2.
Experimental results were studied to determine the relationships between positioning precision of a differential global positioning
system (DGPS) and forest type, antenna height, and season, and to clarify the relationship between sampling number and the
convergence of positioning precision. Observation was carried out for 24 h. Mean circular area probability (CEP95) was 2.80 m for deciduous broadleaved trees, and 4.99 m for conifers. The mean CEP95 taken at 7 m height (3.14 m) was higher than that at 1 m height (3.92 m) at all sites. The mean CEP95 taken during the defoliation season (2.65 m) was slightly better than during the foliation season (2.96 m). There were significant
differences between forest types (P < 0.001) and antenna heights (P < 0.05). Positioning precision was not noticeably improved if the sampling number was around ten or less. A sampling number
of 100–1000 or more is required before substantial improvements can be expected. As long as high positioning precision is
not required, it is acceptable to use 2D & 3D modes and relatively few samples to take measurements.
Received: April 24, 2002 / Accepted: October 10, 2002
Correspondence to:I. Sawaguchi 相似文献
3.
J. Ilic 《Wood Science and Technology》1999,33(5):425-437
Summary Assessments of internal checking and the physical properties of 124 trees of Eucalyptus regnans F. Muell. have shown that for material dried under relatively mild predryer conditions (30 °C, 65% RH) internal checking
was highly positively correlated with each of collapse, moisture content and normal shrinkage, and weakly negatively correlated
with total external shrinkage. Collapse alone explained 47% of the variation in internal checking. Incidence of internal checking
in sample boards could be estimated with moderate success by each of the following properties measured on board ends: collapse,
the number of internal checks and initial moisture content. Material with high mean basic density above 530 kg/m3 was associated with low levels of internal checking and collapse. However, the maximum naturally occurring density of E. regnans was not high enough to obviate collapse and internal checking. It was observed that growth rings in 100 × 50 mm backsawn
boards in which the earlywood air-dry density was below 450 kg/m3 showed internal checking. The size and number of internal checks increased with a decrease in earlywood density. It was shown
that drying E. regnans below temperatures of 24–30 °C does not eliminate collapse, thus raising doubt about the validity of a temperature threshold
concept in that range.
Received 17 September 1997 相似文献
4.
J. Ilic 《Wood Science and Technology》2001,35(1-2):157-166
Dynamic elastic modulus (EL) and wave velocity (V) were determined using resonance vibrations from initially green, 100 × 50 mm sample boards of Eucalyptus regnans F. Muell., and after several stages of drying to oven dry. EL and V were determined from impact induced vibrations and spectral analysis. EL and V from green wood were positively related to basic density and normal shrinkage, only V was negatively related to green
density, and both EL and V were negatively related to green moisture content and the number of internal checks after drying. The latter relationship
has the potential to provide a simple method of segregating highly check prone material. No significant relationships were
obtained with collapse. Outside the hygroscopic range, in low shrinkage material, EL increased little or gradually, while in high shrinkage, collapse prone material, it increased more rapidly, but no clear
breakpoint was evident. In the hygroscopic range, EL increased rapidly in all samples. V increased curvilinearly throughout the entire moisture range, but no difference between
collapse prone and non-collapse prone material was observed.
Received 16 February 1998 相似文献
5.
Particleboard made from hammer milled black spruce bark residues 总被引:1,自引:0,他引:1
Summary The disposal of bark residues is an important problem for the forest industry. An important proportion of the bark produced
by the paper and lumber industries is used for energy production, but a significant amount of bark is still unused. The objective
of this study was to determine the technical feasibility of making particleboards from black spruce bark residues bonded with
urea formaldehyde resin and meeting the indoor performance requirements for wood particleboards. In the positive case, this
would define a new use for black spruce bark residues. Fresh black spruce bark residues were obtained from a sawmill located
in the northeast part of the province of Quebec, Canada. The bark was kiln-dried at 60 °C, the particles were generated from
a hammermill and sieved. Particles from 0.02 to 2.0 mm were used in the surface layers and particles from 2.0 to 6.0 mm were
used in the core layer. Particleboards of 540 × 560 × 16 mm were made with a laboratory hot press following a factorial design
with two manufacturing variables at three levels: (1) wood particles content of the surface layers (0, 25, 50 percent); and
(2) UF resin content of the surface layers (12, 14 and 16 percent) with a UF resin content in the core of 8 percent. This
resulted in a factorial design of 9 different combinations repeated 3 times for a total of 27 boards. It was observed that
the heating kinetics varied according to the wood particles content in the surface layers. The compression ratio of the mat
and the board internal bond, modulus of elasticity, modulus of rupture, linear expansion and thickness swell were determined.
The results show that it is technically possible to make particleboard from bark residues meeting the American National Standard
Institute indoor requirement for wood particleboard under certain conditions. The modulus of rupture of the boards was the
most critical property in this study. The best mechanical properties were obtained with a 50 percent wood content and 14 percent
resin content in the surface layers. The particleboards produced in this study did not meet the minimal requirements for linear
expansion. The temperature measurements performed in the core of the mat during hot pressing show that heat transfer improves
with an increase in wood particles content in the surface layers.
Received 15 June 1998 相似文献
6.
Akiko Sasaki Shozo Shikenya Kazuhiko Takeda Takayuki Nakatsubo 《Journal of Forest Research》2007,12(1):68-74
To estimate the importance of leaching of dissolved organic matter (DOM) as a pathway through which organic matter is supplied
to stream ecosystems, we examined the amount of leachate over time and chemical properties of DOM leached from leaves in different
conditions. The samples used were green leaves, yellow senescent leaves, and leaf litter of Salix gracilistyla Miq., which is the dominant riparian plant species in the middle reaches of rivers in western Japan. We analyzed dissolved
organic carbon (DOC), total sugar, and polyphenol in the leachate of leaf samples collected from a fluvial bar in the middle
reaches of the Ohtagawa River in Hiroshima Prefecture, Japan. Considerable leaching of DOC from senescent leaves [37.3 mg g−1 dry weight (dw) leaf] and leaf litter (8.1 mg g−1 dw leaf) occurred within 24 h after immersion. In contrast, DOC leached from green leaves was negligible until 1 week after
leaf immersion. Carbon loss of leaves by leaching within 24 h after leaf immersion was estimated to be less than 8%, suggesting
that leaching of DOC from S. gracilistyla leaves is a minor pathway through which organic matter is supplied to stream ecosystems. DOM leached from the leaves included
sugar and polyphenol, which were among the major chemical forms of DOM leached from the leaves (based on the molecular mass).
In a laboratory experiment in which the difference in the stability of DOM between the chemical forms was examined, sugar
decomposed more rapidly than polyphenol. 相似文献
7.
Vibrational properties and fine structural properties of wood were measured at high temperatures. Sitka spruce (Picea sitchensis Carr.) and Shioji (Japanese ash, Fraxinus spaethiana Lingelsh.) were used as specimens. The specimens, the system to support them, a magnetic driver, and a deflection sensor
were in an electric drying oven, where vibration tests were conducted. The heating temperatures ranged from room temperature
to 200 °C in 25 °C increments in both heating and cooling processes. X-ray diffractometry was carried out using positive sensitive
proportional counter (PSPC) at room temperature to 200 °C in 20 °C increments in both heating and cooling processes.
Received 13 December 1999 相似文献
8.
Takahisa Nakai Hisashi Abe Takeshi Muramoto Tetsuya Nakao 《Journal of Wood Science》2005,51(5):441-447
The relationship between sap flow rates and diurnal fluctuation of stems was investigated in cloned 3-year-old saplings of
Cryptomeria japonica D. Don grown in a phytotron with irrigation every 2 days. The improved stem heat balance method and a strain gauge were used
to measure sap flow rate and diurnal fluctuation of the stem. The sap flow rate reacted to lighting conditions, increasing
and decreasing immediately after lights-on and lights-off, respectively. The tangential strain on the surface of the inner
bark exhibited a reaction that followed but opposed the reaction of the sap flow rate to lighting conditions. Based on the
changes in sap flow rate, there seemed to be four phases in diurnal sap flow: phase A1 began with lights-on, when the sap flow rate increased, and lasted about 2 hours. In the following phase, A2, the sap flow rate remained almost constant at 1.3 g/min for about 10 h, and then declined for about 2 h as lights-off approached.
In phase B, the early period of darkness, the sap flow declined quickly and then more slowly, for about 4 h, until the start
of the second dark period, phase C, when the sap flow rate became almost constant at 0.05 g/min for about 6 h. The first derivative
of each sap flow rate and the corresponding tangential strain were calculated, and the results indicated a negative correlation
between the two variables in all periods. In particular, the relationship between the first derivative values exhibited a
highly negative correlation in phases A1 and B, expressed as a primary formula. Sap flow rate was found to continue for some time after lights-off, and this compensated
for reduced evaporative effects, albeit at a slow rate, over 4 h. The total amount of sap flow in the dark was only about
9% of that in the light, disregarding transpiration in the dark for simplicity. Thus, the total amount of sap flow responsible
for swelling of the stem was about 9% of that consumed in transpiration during the light period. 相似文献
9.
Test samples of Japanese larch (Larix leptolepis) heartwood and Japanese beech (Fagus crenata) sapwood were heated for 22 h at constant temperatures (50°–180°C) under three water content conditions. Raman spectra of
the samples were recorded before and after the heat treatments, and spectral changes in the range from 1000 cm−1 to 1800 cm−1 were evaluated using the difference spectrum method. For both wood species, the Raman band intensity at 1655–1660 cm−1 due mainly to the C=C and C=O groups in lignin clearly decreased with increasing heat-treatment temperature (HTT). The spectral
change was thought to reflect the progress of condensation reactions of lignin molecules during the heat treatment. Moreover,
the decrease in band intensity was considerably facilitated by the presence of water in the cell wall, suggesting that the
condensation is closely related to the softening of lignin. From the spectral changes in the wavenumber region of 1200–1500 cm−1, it was considered that wood constituents are partially decomposed at the higher HTT.
Part of this article was presented at the 53rd Annual Meeting of the Japan Wood Research Society, Fukuoka, March 2003 相似文献
10.
Gerald Martin S. P. Geetha Sudhakar S. Raja A. V. Raghu Indira Balachandran P. N. Ravindran 《Journal of Forest Research》2006,11(6):461-465
A micropropagation protocol was developed for Celastrus paniculatus, a vulnerable medicinal plant. Cultures were initiated from nodal explants collected from young shoots of a 12-year-old plant
in MS basal medium. An average of five shoots were produced in MS medium supplemented with 1.5 mg l−1 benzyl adenine (BA) and 0.1 mg l−1 naphthalene acetic acid (NAA) after two subculture cycles with a 30-day interval. Continuous subculture in the same medium
for three more cycles resulted in reduction of the number of multiple shoots (2 or 3 shoots), vitrification of the shoots,
and callus formation. Vitrification of cultures could be overcome by the use of MS medium supplemented with lower concentrations
of BA (0.05 mg l−1) and NAA (0.01 mg l−1). Among the various rooting trials, ex vitro rooting of shoots with simultaneous hardening was most efficient. The method
standardized in the present study is simple, as it eliminated separate steps for in vitro rooting and hardening. Qualitative
chemical similarity of the tissue culture regenerants with the mother plant was confirmed using high performance thin-layer
chromatographic (HPTLC) profiling. 相似文献
11.
A non-destructive sampling strategy for basic density, based on removing 12 mm bark-to-bark cores, was developed in E. globulus and E. nitens. Fifty trees of each species, aged 5 to 9 years, were sampled across a range of sites. Core samples were removed on both
a north-south and an east-west axis from 6 fixed heights in the base of the tree (0.5 m, 0.7 m, …, 1.5 m). Whole-tree values
were calculated from disc samples removed at eight percentage heights (0, 10, 20, …, 70%) and correlations between the cores
and whole-tree values were used to determine the optimal sampling height. Core samples were found to be reliable predictors
of whole-tree density, explaining between 84% and 89% of the variation between trees. Core sampling of E. globulus and E. nitens to estimate basic density of whole-trees and stands is feasible; cores from trees at all E. globulus sites gave high correlations with whole-tree values. For E. nitens, site differences were apparent, and it is recommended that a small destructive sampling program should be undertaken prior
to commencing a major sampling program. Recommended optimal sampling heights are 1.1 m for E. globulus and 0.7 m for E. nitens. Core orientation was not important and density was not related to tree size. Six whole-tree samples or eight core samples
are required for estimating the mean density of a stand at a specific site to an accuracy of ±20 kg m−3 with a 95% confidence interval.
Received 17 September 1998 相似文献
12.
Steam conditioning of softwood boards after kiln drying is of critical importance for relief of residual drying stresses
and to improve distribution of final moisture content. The conditioning practice in New Zealand includes two steps: immediately
after high temperature (HT) drying the load is cooled until the core wood temperature is 75 to 90°C, and then the stack is
steam conditioned for a period of 1 to 4 hours depending on the lumber thickness and moisture content after drying. In this
work, experimental and theoretical studies were performed to better understand the conditioning process and to investigate
factors which influence its effectiveness. In the experiment, 50 mm thick Pinus radiata sapwood boards were first dried at 120/70°C for 11, 12, 13, 16 and 18 hours, respectively, to varying moisture contents,
and then cooled and steam conditioned for 1 hour. To assess the effectiveness of conditioning, moisture pick-up, moisture
gradient, and transverse residual drying stress (indicated by cup and strain) were measured. It was found that drying wood
to a low moisture content (below 6%) increased the conditioning effectiveness. A separate matched stack was conditioned for
4 hours after 13 hours drying which showed better results than 1 hour conditioning. A mathematical model for wood drying was
extended to include both the cooling and conditioning phases. The model was numerically solved to examine the wood temperature
and moisture content changes during the whole process of drying, cooling and final steam conditioning. Increase in wood temperature,
moisture pickup and moisture gradient during steam conditioning were predicted and validated by the experimental data. This
information is currently being used at the New Zealand Forest Research Institute in simulation of stress development and relief
for drying of Pinus radiata lumber.
Received 6 July 1998 相似文献
13.
G. Vázquez G. Antorrena J. González S. Freire I. Crespo 《Wood Science and Technology》2000,34(4):345-354
Eucalyptus globulus wood was subjected first to HCl–catalysed delignification with 70% acetic acid under conditions realizing an incomplete 3 × 3 × 3
factorial design (HCl concentration 0, 0.025 or 0.05%; temperature 120, 140 or 160 °C; reaction time 1, 2.5 or 4 h), and then
to enzymatic hydrolysis. The hydrolysis kinetics conformed to both Ghose's empirical model and a biexponential equation. The
biexponential fit implies the presence of both readily and reluctantly hydrolysed cellulose fractions, and the fitted coefficients
show hydrolysis yield to depend largely on the digestibility of the latter. Multiple regression of performance variables on
pulping conditions showed that neither the rate nor the extent of hydrolysis is greatest for pulps with minimum lignin or
xylose contents; we attribute this circumstance to the condensation and precipitation of lignin under severe pulping conditions,
which protects the cellulose of the pulp from enzymatic attack.
Received 20 June 1998 相似文献
14.
Adhesion problems sometimes occur during the production of laminated wood products. To minimize such quality problems, there
is a need for a nondestructive test that can provide continuous control of the process and the product. This study presents
results from measurements performed to evaluate the potential of pulse thermography as a method to detect glue deficiency
in laminated wood. Defect depth, defect size, and degree of glue deficiency have been varied. The surface layer was made of
merbau (Intsia bijuga) and the substrate of Scots pine (Pinus silvestris). The results showed that pulse thermography is a promising tool for detecting glue deficiency underneath the thin laminated
wood surface layers, mainly because of the short inspection time. Lack of glue with a minimum thermal defect size of 3 was
detectable (thermal defect size is defined as the quotient of defect size and defect depth). The penetration depth was 1.0 mm
and the highest contrast, 0.62°C, was achieved for one of the largest defects (24 mm) below the thinnest (0.5 mm) surface
layer after 1 second. Starved glue joints showed about half the contrast compared to areas with total lack of glue.
Received: April 24, 2002 / Accepted: July 26, 2002
Acknowledgments We gratefully acknowledge the support of this work from the Knowledge Foundation and The Swedish Wood Association. 相似文献
15.
C. A. Raymond L. R. Schimleck A. Muneri A. J. Michell 《Wood Science and Technology》2001,35(3):203-215
Within-tree variation in kraft pulp yield, predicted using near infrared reflectance analysis, was studied in thirty trees
of E. globulus and fifty trees of E. nitens to develop a non-destructive sampling strategy. Trees, aged 5 to 9 years, were sampled across a range of sites in southern
Australia. Simulated core samples were removed at six fixed heights easily accessible from the ground (0.5, 0.7, ... 1.5 m)
and at seven percentage heights (0, 20, 30, ... 70%). Whole-tree values, calculated from percentage height data, were correlated
with the core data to determine the optimal sampling height. Core samples were found to be good predictors of whole-tree pulp
yield for E. globulus, with simulated cores taken from the recommended sampling height (1.1 m) explaining more than 50% of variation in whole-tree
pulp yield. Results for E. nitens were variable with large site differences apparent. On high quality sites, core samples from the recommended sampling height
(0.9 m) were good predictors of whole-tree pulp yield, explaining around 60% of the variation. On poor quality sites, cores
were poor predictors of whole-tree pulp yield. Radial orientation of cores was not important and predicted pulp yield was
not related to tree size, basic density or fibre length. To estimate stand mean pulp yield to an accuracy of ±1% would require
sampling 6 trees of E. globulus and 4 trees for E. nitens using either multiple discs or core samples. A single sampling height (1.1 m) is recommended for sampling for basic density,
fibre length, fibre coarseness and predicted pulp yield in E. globulus. For E. nitens the recommended sampling height for basic density and fibre length is 0.7 m and 0.9 m is recommended for predicted pulp yield
on good quality sites.
Received 17 September 1998 相似文献
16.
The relations among internal temperature, internal pressure, and moisture content distribution in sugi square lumber during
high-frequency (HF) heating were determined to clarify the mechanism of water movement during the combination of HF heating
and hot air exposure. Green sugi square lumbers were subjected to HF heating under atmospheric pressure. The water movement
and pathways in the lumber during HF heating were also investigated. Results showed that internal pressure is the driving
force of water movement. HF heating causes a rise in the internal temperature and internal pressure in sugi square lumber.
Ordinarily, water in lumber evaporates from the surfaces of lumber during hot air drying. However, with HF heating the internal
pressure is generated by the increased temperature, and liquid water is driven not only parallel to the grain but also perpendicular
to the grain of the lumber. The ratio of the amount of liquid flow in the parallel and perpendicular directions ranged from
2 : 3 to 1 : 3. When the movement of water in the lumber was traced with a 0.5% aqueous solution of acid fuchsin, water was
found to move through the lumber in the longitudinal direction and then flow in a direction perpendicular to the grain or
in the radial and tangential directions.
Received: June 15, 2001 / Accepted: February 8, 2002
Acknowledgment The authors thank Dr. O.R. Pulido, Institute of Wood Technology, Akita Prefectural University, for discussions and for proofreading
this paper.
Part of this research was presented at the 51st Annual Meeting of the Japan Wood Research Society, Tokyo, April 2001
Correspondence to:Y. Kawai 相似文献
17.
Delignified hinoki wood and cellulose as well as hinoki and lauan woods were carbonized at 590°C for 1 h. The dielectric properties
of these specimens were measured at 20°C in a frequency range of 20 Hz to 1 MHz. Inflection points in the dielectric constant
(ε′) versus the logarithm of frequency (log f) curves as well as in the logarithm of the electric conductivity (log σ) versus log f curves for all specimens prepared were recognized. Peaks in the dielectric loss and the imaginary part of the complex conductivity
versus the log f curves were detected in the frequency location corresponding to the inflection point in the ε′ and log σ versus log f curves. It was considered that this relaxation was responsible for the interfacial polarization observed in heterogeneous
materials because no permanent dipoles existed in the specimens carbonized above 500°C. The Cole–Cole circular arc law was
applied to account for this relaxation. Similar average relaxation times were obtained for all specimens. These results suggested
that the observed relaxation was ascribed to interfacial polarization at microscopic levels in the cell walls. 相似文献
18.
Sanjaya Bagyalakshmi Muthan Thrilok Singh Rathore Vittal Ravishankar Rai 《Journal of Forest Research》2006,11(3):203-209
Santalum album is known as East Indian sandalwood. It is the most economically important tree harvested for heartwood oil, and India is
among the chief exporters of sandalwood and its products. Multiple shoots were induced from nodal shoot segments derived from
a 50- to 60-year-old candidate plus tree (CPT) on Murashige and Skoog (MS) medium supplemented with 0.53 μM α-naphthaleneacetic acid (NAA) and 11.09 μM 6-benzylaminopurine (BA). In vitro differentiated shoots were multiplied on MS medium with 0.53 μM NAA, 4.44 μM BA, and additives: 283.93 μM ascorbic acid, 118.10 μM citric acid, 104.04 μM cystine, 342.24 μM glutamine, and 10% (v/v) coconut milk. New shoots were harvested repeatedly for up to three subculture passages on fresh
medium at 4-week intervals. Microshoots treated with 98.4 μM indole-3-butyric acid (IBA) for 48 h produced roots on growth-regulator-free, quarter-strength MS basal salts medium with
vitamin B5 and 2% sucrose. In vitro root induction was achieved from microshoots pulsed with 1230 μM IBA for 30 min in soilrite rooting medium. The percentage of rooting in soilrite was higher than that for agar medium, and
in vitro raised plants were established in the field and showed normal growth. 相似文献
19.
This study investigated the effect of a compressive load of 0.092 MPa on the history of the tangential strains in Japanese
larch (Larix leptolepis Gordon) log cross sections subjected to external compressive load during radio-frequency/vacuum drying. The external compressive
load of 0.092 MPa played a role in inducing cracking in the outer zone of the log cross section, combining with other tensile
strains. However, it also played a role in reducing the heart checks in the core of log cross section when exerted on the
cross section of log cross section. 相似文献
20.
Tamami Kawasaki Kweonhwan Hwang Kohei Komatsu Shuichi Kawai 《Journal of Wood Science》2003,49(3):199-209
The fundamental in-plane shear properties were investigated for the wood-based sandwich panel of plywood-overlaid low-density
fiberboard (SW) manufactured at a pilot scale to develop it as a shear wall. The shear test method using tie-rods standardized
for shear walls was applied to SW with dimensions of 260 mm square and 96 mm thick as a small shear wall and to plywood (PW)
and thick low-density fiberboard (FB). The shear modulus and shear strength of PW, FB, and SW were determined. To measure
the shear deformation angle, a displacement meter and strain-gauge were used. The shear moduli of PW (0.68 g/cm3) and FB (0.25–0.35 g/cm3) were 460 and 21–58 MPa/rad, respectively. The shear modulus of SW as a composite was analyzed. Some experimental models
of SW were proposed (i.e., rigid-α, rigid-β, flexible, and semirigid models). The shear modulus of SW (0.35–0.40 g/cm3) evaluated based on the rigid-α and semirigid models were 73–89 and 109–125 MPa/rad, respectively. The theoretical shear modulus of SW was calculated to
be 110–129 MPa/rad.
Received: May 9, 2001 / Accepted: June 26, 2002
RID="*"
ID="*" Part of this report was presented at the 50th Annual Meeting of the Japan Wood Research Society, Kyoto, Japan, April
2000; and the 5th Pacific Rim Bio-Based Composite Symposium, Canberra, Australia, December 2000
Acknowledgments The authors express our deep gratitude to Mr. Noritoshi Sawada (Hokushin Co.), Dr. Wong Cheng, and their cooperative members
for their expert technical support for the preparation of manufacturing the thick fiberboard and sandwich panel. We are grateful
also to Drs. Min Zhang, Kenji Umemura, Wong Ee Ding, and Guangping Han for their great help and advice in manufacturing the
thick panels. The authors are grateful to Hokushin Co. for the fiber and resin and to Ishinomaki Gouhan Co. for the plywood.
We thank Mr. Makoto Nakatani for his expert assistance when preparing the specimens for the shear test. Funding provided by
the Research Fellowship of the Japan Society for the Promotion of Science for Young Scientists as a JSPS Research Fellow is
also gratefully acknowledged. 相似文献