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1.
Subyakto Bambang Subiyanto Toshimitsu Hata Shuichi Kawai 《Journal of Wood Science》2003,49(3):241-247
Some tropical fast-growing woods were converted to edge-jointed lumber, and their fire-retardant properties due to chemical
coating were evaluated using cone calorimetry and a standard fire test. The woods used were Indonesian and Malaysian albizia
and gmelina plantation trees, with Japanese hinoki as a reference. The lumber was coated with 100 g/m2 of trimethylol melamine phosphoric acid in a 25% aqueous solution. The treated and untreated lumber was tested in a laboratory-scale
exposure furnace in accordance with JIS A 1304 and the cone calorimeter test with heat flux of 40 kW/m2 following the ISO 5660. Results showed that fire endurance of all lumber was enhanced by the treatment. The fire-retardant
properties were improved with increasing surface density. Though a similar trend was seen, the fire-retardant properties of
the lumber revealed by the cone calorimeter test were inferior to those seen with standard fire test. Addition of thermocouples
to the cone calorimeter allowed us to obtain information on the critical temperature (260°C) and charring temperature (300°C)
of the lumber.
Received: January 23, 2002 / Accepted: July 15, 2002
Acknowledgment The authors thank Dr. Shigehisa Ishihara, Professor Emeritus of the Wood Research Institute, Kyoto University for his suggestions
about this experiment. 相似文献
2.
On the loss factor of wood during radio frequency heating 总被引:2,自引:0,他引:2
The radial direction loss factor of full-size western hemlock sapwood and heartwood, as well as western red cedar heartwood
timbers was measured using the direct calorimetric method with a laboratory-scale radio frequency/vacuum dryer at the frequency
of 13.56 MHz, moisture content range between 10 and 80%, temperature range between 25 and 55 °C, and root mean square (rms)
electrode voltages of 0.8 and 1.1 kV, respectively.
The results indicated that the moisture content, temperature, electric field strength and wood type significantly affected
the loss factor. Empirical regression equations were derived based on the experimental data that made possible the calculation
of the loss factor and power density within wood during RF heating.
Received 18 January 1997 相似文献
3.
Relaxation mechanism of residual stress inside logs by heat treatment: choosing the heating time and temperature 总被引:1,自引:0,他引:1
Some methods to reduce residual stress inside logs have been reported, although the conditions for stress relaxation are
not yet clarified. Our study using precise experiments revealed that residual stress relaxation occurs only when both heat
and moisture exist inside the logs. We then determined the heating time and temperature required to relax the residual stress
inside the logs. Short air-drying treatments did not relax residual stress even though free water in the logs was greatly
reduced. The residual stress of the 33-h 80°C-heated bolts was relaxed, whereas that of the 48-h 70°C-heated bolts was not.
As for the influence of treatment time, bolts heated at 100°C were relaxed after 18 h of treatment. The 13-h heated bolts
did not show any relaxation. Therefore, residual stress relaxation occurred rapidly owing to the thermomechanical change of
the individual wood components comprising the cell wall. The moisture content inside all the bolts was much higher than the
fiber saturation point. This is because relaxation occurs only when the heating temperature is maintained above 80°C for a
particular duration of treatment.
Received: December 12, 2001 / Accepted: February 18, 2002
Present address: Institute for Structural and Engineering Materials, National Institute of Advanced Industrial Sciences and Technology, Independent
Administrative Institution, Nagoya 463-8560, Japan Tel. +81-52-736-7320; Fax +81-52-736-7419 e-mail: m.nogi@aist.go.jp
Part of this report was presented at the 50th Annual Meeting of the Japan Wood Research Society, Kyoto, April 2000
Correspondence to:M. Nogi 相似文献
4.
Yutaka Kataoka Makoto Kiguchi Takeshi Fujiwara Philip D. Evans 《Journal of Wood Science》2005,51(5):531-536
Low density wood is more rapidly eroded than denser wood when exposed to the weather, possibly because it is more susceptible
to photodegradation. Fourier transform infrared microscopy was used to examine: (1) the depth of photodegradation in earlywood
and latewood of sugi (Japanese cedar) and earlywood of hinoki (Japanese cypress) exposed for up to 1500 h to artificial sunlight
emitted by a xenon lamp (375 W/m2 within the 300 to 700 nm spectral range); and (2) the relationship between the density of wood tissues and depth of photodegradation.
The depth of photodegradation varied between species (sugi and hinoki) as well as within a growth ring (sugi earlywood and
latewood), and there was an inversely proportional relationship between depth of photodegradation and wood density. These
findings may explain why low density earlywood is more rapidly eroded than latewood during weathering, and more generally,
why there is an inverse relationship between the density of wood species and their rate of erosion during artificial and natural
weathering.
Part of this work was presented at the 54th Annual Meeting of the Japan Wood Research Society, Sapporo, August 2004 相似文献
5.
Binderless particleboards were manufactured from sugi (Cryptomeria japonica D. Don) heartwood and sapwood by hot-pressing (pressure: 5 MPa; temperatures: 180°, 200°, and 220°C; times: 10, 20, and 30
min), and the board properties [internal bonding (IB), thickness swelling (TS), water absorption (WA)] were investigated to
evaluate the self-bonding ability. The IB, TS, and WA of the boards from sugi heartwood were better than those of the boards
from sugi sapwood at any hot-pressing condition. Therefore, it was suggested that the self-bonding ability of sugi heartwood
was superior to that of sugi sapwood. Then, sugi heartwood and sapwood powder with grain size 10 βm were used as a binder
for plywoods. Four kinds of plywood were manufactured from the combination of powder and veneer, both of which were prepared
from sugi heartwood and sapwood under the same hot-pressing conditions as the binderless particleboard, and the adhesive shear
strength and wood failure of the plywood were investigated. As a result, the plywood composed of sugi heartwood veneer met
the second grade of JAS for plywood, when either powder was used as a binder, when they were pressed at 200°C for 20–30 min
and 220°C for 10 min. 相似文献
6.
Han-Min Park Masami Fushitani Keiichi Sato Takafumi Kubo Hee-Seop Byeon 《Journal of Wood Science》2006,52(3):220-229
To improve the performance of cross-laminated woods, 30 types of three-ply parallel-laminated and cross-laminated woods were
prepared from five species with various densities and shear compliances in cross section, and their bending creep performances
were investigated on the basis of our previous research in cross-laminated wood made with sugi (Japanese cedar). The creep
deformation perpendicular to the grain was decreased by cross laminating. The creep deformation perpendicular to the grain
of parallel-laminated woods (P⊥ type), that perpendicular to the grain of face laminae of cross-laminated woods (C⊥ type), and also that parallel to the grain of face laminae of cross-laminated woods (C║ type) tended to decrease with increasing density of species used for perpendicular-direction lamina. It was found that the
extent of the decrease was greater in creep deformation than in initial deformation. The degrees of anisotropy for both deformations
of laminated wood were markedly decreased by cross laminating. The extent of the decrease was much greater in creep deformation
than in initial deformation and considerably smaller in buna with higher density than in sugi with lower density. The measured
values of initial deformation and creep deformation of C⊥ type were almost equal to the calculated values obtained from the measured values of parallel-laminated woods, whereas the
measured values of both deformations of C║ type were much greater than their calculated values and increased markedly with increasing shear compliance in cross section
of perpendicular-direction lamina used for core. The ratios of the average of measured values to the calculated value of C║ type ranged from 1.05 (katsura) to 1.50 (sugi) in initial deformation and from 1.30 (katsura) to 3.69 (sugi) in creep deformation.
This result can be explained as the effect of deflection caused by shear force. 相似文献
7.
The species richness of trees, shrubs and climbing plants was investigated in 41 sugi (Cryptomeria japonica D. Don) plantations of different stand age and area in southern Kyushu, southwestern Japan. Altogether 174 species were found,
of which 145 infrequent species were selected for analysis. Two groups were extracted from the species list according to their
occurrence in older (49 spp.) or younger (28 spp.) stands, the latter containing a higher percentage of climbing plants and
species with wind-dispersed seeds. In contrast, the older stand group contained major tree components typical of seminatural,
evergreen broadleaved forests in the region and was more heavily dependent on stand age, especially for species with gravity-
and frugivore-dispersed seeds, showing a gradual increase up to 60 years old. The species richness was less correlated with
edge perimeter facing seminatural forests and the years after latest thinning. The juxtaposition of plantation compartments
with stands of seminatural forest or other plantations, as well as the compartment's origin as former plantation site or a
seminatural stand, had relatively little influence on species richness. However, topographic variation was important in determining
the species composition, with valley stands having higher species richness and containing many plants typical of the regional
seminatural forests. These results suggest that (1) the major trend of species richness is determined by the presence of old
stand type species, (2) topographic variation of species richness remains even after establishment of plantations, and (3)
the normal rotation period of sugi plantations (35–40 years) may therefore be too short to conserve the maximum potential
species diversity within the working forest.
Received: June 4, 2001 / Accepted: August 26, 2002
Acknowledgments We wish to thank the staff of the Miyazaki University Forests for cooperation in the fieldwork. A part of this study was
supported by the Grant-in-Aid for Scientific Study from the Ministry of Education, Science and Culture of Japan (no. 09041071
and no. 10460068).
Correspondence to:S. Ito 相似文献
8.
We evaluated the protective effects of floor cover against soil erosion in three types of forest located on steep slopes
under a humid climate: 22- and 34-year-old Chamaecyparis obtusa (hinoki), 34-year-old Cryptomeria japonica (sugi), and 62-year-old Pinus densiflora (red pine) stands. We measured sediment transport rates (sediment mass passing through one meter of contour width per millimeter
of rainfall), using sediment traps, before and after removing floor cover. Raindrop splash erosion was dominant in the experimental
stands. Floor cover percentage (FCP) during the preremoval stage varied from 50% to 100% among the four stands, and sediment
transport rates ranged from 0.0079 to 1.7 g m−1 mm−1. The rates increased to 1.5–5.6 g m−1 mm−1 immediately after removing floor cover, and remained high throughout the experiment. The presence of physical cover near
the ground has a crucial effect on sediment transport on forested slopes. The protective effect ratio (the ratio of the sediment
transport rate in a control plot to that in the removal plot) in a young hinoki stand, in which the FCP decreased markedly,
was 0.3 at most, which is close to the rate for bare ground. The protective effect ratio in the red pine stand was ≤0.003.
We concluded that the protective effect of floor cover in undisturbed forests in Japan differs by over two orders of magnitude,
based on comparisons with previous studies.
Received: March 11, 2002 / Accepted: August 16, 2002
Present address: Department of Forest Site Environment, Forestry and Forest Products Research Institute, Ibaraki 305-8687 Japan Tel. +81-298-73-3211;
Fax +81-298-74-3720 e-mail: miura@affrc.go.jp
Present address: Department of Forest Site Environment, Forestry and Forest Products Research Institute, Ibaraki 305-8687 Japan Tel. +81-298-73-3211;
Fax +81-298-74-3720 e-mail: miura@affrc.go.jp
Acknowledgments This study was supported by the Research Council of the Ministry of Agriculture, Forestry, and Fisheries, of Japan. We thank
H. Ujihara, S. Ujihara, and M. Ogasawara in Otoyo, Kochi, who provided the experimental stands used in this study. We also
thank K. Hirai, S. Kuramoto, E. Kodani, and the rest of the staff at the Shikoku Research Center, Forestry and Forest Products
Research Institute, for their help in conducting the experiments.
Correspondence to:S. Miura 相似文献
9.
Sugi green logs with red or black heartwood were smoke-heated, and the changes in the color of the heartwood after ultraviolet
(UV) (λ = 365 nm) radiation exposure were then observed. After UV radiation exposure, the redness and yellowness increased in both
the red and black heartwoods, whereas the brightness decreased. In the black heartwood, the resulting color turned from yellowish
white to reddish brown. Reddening in black heartwood after exposure to a combination of smoke heating and UV radiation is
thought to be due to a decrease in brightness and an increase in both redness and yellowness. However, the degree of change
in heartwood color by UV radiation exposure was not greatly affected by smoke-heating treatments of various lengths. When
methanol extracts were fractionated and exposed to UV radiation, the yellowness increased in the n-hexane-soluble portion and the redness increased in the acetone-soluble fractions from the n-hexane-insoluble portion. These results suggest that the n-hexane-soluble fraction contains the substances that allow heartwood color to change to yellow after UV radiation exposure,
and the acetone-soluble-fraction from the n-hexane-insoluble portion contains the substances that allow it to change to red.
Received: November 14, 2001 / Accepted: June 3, 2002
Acknowledgment This research was supported in part by a Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of
Science.
This study was presented in part at the 51st Annual Meeting of the Japan Wood Research Society, Tokyo, April 2001
Correspondence to:N. Yoshizawa 相似文献
10.
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
11.
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
12.
Feasibility of supercritical carbon dioxide as a carrier solvent for preservative treatment of wood-based composites 总被引:4,自引:0,他引:4
Supercritical carbon dioxide (SC-CO2) was tested for its potential as a carrier solvent for preservative treatment of solid wood and wood-based composites. A
preliminary trial showed that the treatability of solid wood varied with its original permeability and that the SC-CO2 treatment was not promising for refractory timber species such a Larix leptolepis Gordon. In contrast, 3-iodo-2-propynyl butylcarbamate (IPBC)/SC-CO2 treatment resulted in enhanced decay resistance without any detrimental physical or cosmetic damage in all structural-use
wood-based composites tested: medium density fiberboard, hardwood plywood, softwood plywood, particleboard, and oriented strand
board (OSB). Further trials under various treatment conditions [25°C/7.85 MPa (80 kgf/cm2), 35°C/7.85 MPa, 45°C/7.85 MPa, 35°C/11.77 MPa (120 kgf/cm2), and 45°C/11.77 MPa] indicated that although small changes in the weight and thickness of the treated materials were noted
the strength properties were not adversely affected, except for a few cases of softwood plywood and oriented strand board.
The results of this study clearly indicated that the treatment condition allowed SC-CO2 to transport IPBC into wood-based composites, and the optimum treatment condition seemed to vary with the type of wood-based
composite.
Received: October 24, 2001 / Accepted: February 15, 2002
Part of this work was presented at the 51st Annual Meeting of the Japan Wood Research Society, Tokyo, April 2001; and the
32nd Annual Meeting of the International Research Group on Wood Preservation, Nara, May 2001
Correspondence to:M. Muin 相似文献
13.
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
14.
Manufacture of plywood bonded with kenaf core powder 总被引:3,自引:0,他引:3
Kenaf (Hibiscus cannabinus L.) core powder was used as a binder to manufacture three-ply plywoods of sugi (Cryptomeria japonica D. Don) by conventional hot pressing under various manufacturing conditions: hot-pressing conditions (pressure, temperature,
and time) and powder conditions (grain size, spread volume, and moisture content). The adhesive shear strength and wood failure
of plywoods were measured in accordance with the Japanese Agricultural Standard (JAS) for plywood. The result showed that
fine kenaf core powder played a role as an effective binder when plywoods were pressed at high pressure, which caused extreme
compression of veneer cells. In addition, the adhesive shear strength of plywoods in dry conditions was high regardless of
pressing temperature and time, but it was sensitive to pressing temperature and time in wet conditions. The highest adhesive
shear strength was obtained from plywoods manufactured with kenaf core powder (grain size 10 μm, spread volume 200 g/m2, moisture content 8.6%) under hot-pressing conditions (pressure 5.0 MPa using distance bars 4 mm thick, temperature 200°C,
time 20–30 min). However, the plywood could not meet the requirement for the second grade of plywood by JAS because of its
low water-resistance properties.
Part of this article was presented at the 58th Annual Meeting of the Japan Wood Research Society, Tsukuba, March 2008, and
the 10th World Conference on Timber Engineering, Miyazaki, June 2008 相似文献
15.
A. Itoh T. Yamakura S. Tan J. J. Kendawang H. S. Lee 《Journal of Forest Research》2003,8(2):0117-0121
Cuttings from older trees of the Dipterocarpaceae generally lose their ability to root. However, branches in a canopy of
adult dipterocarps are a possible source of cuttings because they show juvenile characteristics in architecture due to “adaptive
reiteration”, suggesting physiological rejuvenation. Effects of resource plant size on the rooting of cuttings and the possibility
of using cuttings from reiterated branches of adult trees were studied for Dryobalanops lanceolata, an emergent dipterocarp species. A cutting experiment with non-mist propagators was conducted for cuttings collected from
resource plants of four different size classes: <2 m, 2–5 m, 8–15 m, and 70 m in height. The smallest size class included
two different age classes: <2 and >2 years old. Cuttings from the tallest resource plant were collected from reiterated branches.
Rooting percentage was negatively correlated with resource plant size: 77–78% for resource plants <2 m, 63% for 2–5 m, 36%
for 8–15 m, and 0% for 70 m. Rooting percentages of cuttings collected from different individuals were not different for the
2–5 m tall class, while they were significantly different for the 8–15 m tall class. Resource plant size was negatively correlated
with the number of roots for rooted cuttings. No significant relationship was observed between resource plant size and mean
length of each root, total root length or total root dry weight for rooted cuttings. The results suggest the possibility of
collecting cuttings from relatively large resource plants up to 15 m tall and >20 years old if we chose good individuals for
resource plants. The results, however, show the difficulty in using reiterated branches of adult trees as a source of cuttings
for D. lanceolata.
Received: October 15, 2001 / Accepted: November 11, 2002
Acknowledgments We express our sincere thanks to Dr. S. Tamura, Dr. K. Ogino, and Mr. A.A. Hamid for their kind support. The tree tower was
constructed in a cooperative project between Japan and Sarawak supported by the Ministry of Education, Culture, Sports, Science
and Technology, Japan (Grant NP0201). The cutting experiment was partly funded by the Nippon Life Insurance Foundation and
the Japan Society for the Promotion of Science (JSPS-RFTF96R16001).
Correspondence to:A. Itoh 相似文献
16.
Spatial distribution of sporocarps of Suillus pictus A.H. Smith and Thiers was studied in a plot of 6 × 12 m in size established in a stand of Pinus koraiensis Sieb. et Zucc. in Kyoto, Japan for 4 years, and the biomass of mycorrhizas was examined in the last year. S. pictus was dominant in both sporocarp and ectomycorrhizal community in the study plot. The number of S. pictus sporocarps ranged from 0.94 to 1.26 m−2 (surface area) in the study plot and did not vary very much during the study period. Sporocarps of S. pictus occurred in clumps and the distributions of clumps were generally random. As the spots of sporocarp occurrence changed gradually
from year to year, the distributions of sporocarps that occurred successively in 2-year periods overlapped, especially when
analyzed in 9-m2 unit size using the m
*
–m method. Mycorrhizas of S. pictus were distributed in more subplots than its sporocarps. Distribution of mycorrhizas and sporocarps of S. pictus generally overlapped well. The biomass of mycorrhizas and mycelia in the mycorrhizas of S. pictus was estimated at 15.5 g DW m−2 and 6.2 g DW m−2 (surface area) in this plot, respectively. The biomass of mycorrhizas and mycelia in the mycorrhizas supporting the production
of one sporocarp (average dry weight was 0.86 g) of S. pictus was evaluated as about 16.4 and 7.3 g DW, respectively, in this plot.
Received: December 20, 2001 / Accepted: August 12, 2002
Acknowledgments We thank Dr. T. Furuno, Mr. N. Kato, and Dr. I. Nakai for their help in preparing the study plot and collecting sporocarps,
and Prof. K. Yokoyama for the identification of sporocarps. Thanks are also due to Dr. E. Kuno for his suggestion about analysis.
Correspondence to:J. Kikuchi 相似文献
17.
The optimum conditions for β-thujaplicin production in a Cupressus lusitanica cell suspension culture were investigated. The conditions required for β-thujaplicin production were clearly different from the conditions for cell growth. The initial phosphate concentration and
pH did not affect β-thujaplicin production. A total nitrogen source concentration higher than 3.2 mM suppressed production due to the presence
of the ammonium ion. β-Thujaplicin production was observed at 95 mg/l without adding the ammonium ion to the medium. Strict control of major inorganic
nutrients was not necessary to produce β-thujaplicin. This finding seems to be favorable for future automated production of β-thujaplicin in commercial cell culture plants.
Received: October 3, 2001 / Accepted: February 20, 2002
Present address: Teijin Ltd., Matsuyama 791-8530, Japan
Part of this report was presented at the 10th International Symposium on Wood and Pulp Chemistry, Yokohama, Japan, June 1999
Correspondence to:K. Fujita 相似文献
18.
A marine white rot isolate, Phlebia sp. MG-60, secreted lignin peroxidase (LiP), manganese peroxidase (MnP), and laccase under different sea salt incubation conditions.
Its MnP production was strongly enhanced by adding 3% sea salts, and the MnP showed high tolerance to sea salts and NaCl.
The crude enzyme secreted at 3% sea salt concentration by Phlebia sp. MG-60, in which the main component was MnP (cMnP), was then used to bleach unbleached hardwood kraft pulp (UKP) in vitro.
The pulp was brightened 11 points by 4 U of cMnP, and the kappa number was decreased 6 points when only 0.5 mM H2O2 was added continuously. When 0.5 mM H2O2 (1.22 mg H2O2 /g pulp) was added at the initial bleaching, the pulp brightness increased 6 points with a dosage of 4 U of cMnP. When crude
MnPs were employed to bleach UKP with organic-free model white-water instead of the Milli Q water usually used, the pulp was
brightened 10 and 13 points by 4 and 20 U of cMnP, respectively, and 5 and 6 points by 4 and 20 U of MnP, respectively, of
Phanerochaete chrysosporium.
Received: September 28, 2001 / Accepted: March 15, 2002
Correspondence to:R. Kondo 相似文献
19.
Three-dimensional distribution of water in the heartwood of Cryptomeria japonica D. Don was observed by soft X-ray photography. The within-tree variation in the distribution of “wet areas” (water-accumulated
areas in heartwood) was enormous, as was the variation among trees. Although we found no universal pattern of changes in wet
area distributions along the stem axes of all trees, similarities among individual trees within each cultivar and clone were
observed. The difference between the two kinds of wetwood in C. japonica – genetically defined wetwood and secondarily induced wetwood – is discussed, as is the use of soft X-ray photography in Japanese
tree breeding programs.
Received: December 21, 2001 / Accepted: May 1, 2002
Part of this paper was presented at the 46th Annual Meeting of the Japan Wood Research Society, Kumamoto, Japan, April 1996
Correspondence to:R. Nakada 相似文献
20.
Comparison of the decomposition behaviors of hardwood and softwood in supercritical methanol 总被引:2,自引:0,他引:2
The chemical conversion of Japanese beech (Fagus crenata Blume) and Japanese cedar (Cryptomeria japonica D. Don) woods in supercritical methanol was studied using the supercritical fluid biomass conversion system with a batch-type
reaction vessel. Under conditions of 270°C/27 MPa, beech wood was decomposed and liquefied to a greater extent than cedar
wood, and the difference observed was thought to originate mainly from differences in the intrinsic properties of the lignin
structures of hardwood and softwood. However, such a difference was not observed at 350°C/43 MPa, and more than 90% of both
beech and cedar woods were effectively decomposed and liquefied after 30 min of treatment. This result indicates that the
supercritical methanol treatment is expected to be an efficient tool for converting the woody biomass to lower-molecular-weight
products, such as liquid fuels and useful chemicals.
Received: December 19, 2001 / Accepted: March 15, 2002
Acknowledgments This research has been done under the research program for the development of technologies for establishing an eco-system
based on recycling in rural villages for the twenty-first century from the Ministry of Agriculture, Forestry and Fisheries,
Japan and by a Grant-in-Aid for Scientific Research (B)(2) (no.12460144, 2001.4–2003.3) from the Ministry of Education, Culture,
Sports, Science and Technology, Japan.
This study was presented in part at the 45th Lignin Symposium, Ehime, Japan, October 2000 and the 51st Annual Meeting of the
Japan Wood Research Society, Tokyo, Japan, April 2001.
Correspondence to:S. Saka 相似文献