• Transactions of the Korean hydrogen and new energy society
• /
• v.20 no.1
• /
• pp.55-63
• /
• 2009

In this study, thermochemical degradation by acetone solvolysis reaction of siberian spruce wood was investigated for a temperature range of $200{\sim}400^{\circ}C$. The liquid products by acetone solvolysis from siberian spruce wood produced various kinds of aliphatics, cyclic compounds and aromatics included phenols etc. Combustion heating value of liquid products by acetone solvolysis conversion processes was in the range of $8,010{\sim}8,180cal/g$. The energy yield in acetone solvolysis of siberian spruce wood was as high as 74.2% after 40min of reaction at $400^{\circ}C$. The liquid products from the thermochemical conversion of siberian spruce wood could be used as high-octane-value fuels and fuel additives.

• Journal of the Korean Wood Science and Technology
• /
• v.24 no.1
• /
• pp.68-74
• /
• 1996

Present work was undertaken to investigate the origin of milled wood lignin(MWL) in the wood cell wall using immunocytochemical techniques, which can provide the information on the localization of specific antigens(MWL in the present study) to be examined. Spruce MWL dissolved in DMSO and emulsified with Freund adjuvant was injected directly into the mouse spleen. The animals were boostered at two-week intervals after the initial immunization. Blood samples were purified in standard procedures. The characteristics of antibodies against MWL were tested by indirect ELISA. Visualization of MWL was carried out using conventional indirect immunogold-labelling methods on the ultrathin sections of spruce wood. Immuno-TEM observations showed that the immunogold probes were selectively attached to secondary cell walls of spruce wood. The most intense labelling was frequently observed in the S2 layer. In contrast, gold labelling in the lignin-rich regions, such as middle lamella and cell corner was not found. The immuno-TEM provides an indication that spruce MWL originates from the S2 layer.

• Journal of the Korean Wood Science and Technology
• /
• v.27 no.3
• /
• pp.1-6
• /
• 1999

European spruce and maple were to be estimated as raw material of violin family instruments with linear modal analysis to provide the information data for the design of their bodies. Wood specimens cut in different direction were excited by impact hammer to measure the resonant frequency with typical vibrational modes. In spite of lower density than maple, European spruce showed the excellent acoustical properties with higher resonant frequency. And edge-grained spruce had more even frequencies than flat-grained ones to be more acceptable as front plate of violin. Resonant frequency was positively correlated with wood density of each specimen and the coefficients of edge-grained specimens were higher than those of flat-grained specimens of both wood species.

• Journal of the Korean Wood Science and Technology
• /
• v.21 no.2
• /
• pp.9-14
• /
• 1993

Weathering of wood in a region of acid rain was performed by the test which thin veneers of Sitka spruce were exposed to outdoor weathering for a total of 18 weeks, with a daily soaking for 30 minutes in acidified water in the pH range 2~5.6. The weathering measured by weight loss and loss in maximum failure load in tension was accelerated by the increase in the acidity of acidified water and in the period of outdoor exposure. It was also shown that the weathering was accelerated even with low acidic conditions in the case of long exposure period, although the weathering was rapidly accelerated with high acidic conditions. When compared the degree of weight loss with that of loss in failure load by weathering, the latter was much greater. From the results of this research, it could be concluded that at pH 4.0 or below of precipitation, the acceleration of weathering of exterior wood would become serious problems, which would be caused deterioration in performance of exterior wood.

• Journal of the Korea Furniture Society
• /
• v.20 no.6
• /
• pp.560-565
• /
• 2009

It is known that heat treatment decreases the hygroscopicity of wood. Thus heat-treated wood is good for outdoor construction due to its improved dimensional stability. This study is to investigate the hygroscopicity and discoloration of spruce and birch boards heat-treated above $190^{\circ}C$. The equilibrium moisture contents (EMCs) at all relative humidities decreased with the increase of heat treatment temperature and/or time for both spruce and birch. It was revealed that heat-treatment temperature affected more on the hygroscopicity thaan heat-treatment time. The average basic densities decreased for the spruce specimens, but increased for the birch specimens with an increase of the treatment time and/or temperature. The same heat treatment condition (190-8) made the birch specimens darker than the spruce specimens.

• Journal of the Korea Furniture Society
• /
• v.10 no.1
• /
• pp.57-63
• /
• 1999

This study was carried out to analyze the relationship between basic physical properties and acoustical characteristics of imported violin wood and to offer the information on raw material procurement and incoming-material quality control to domestic violin makers which have purchased most raw materials from European exporting countries at high expense. Equilibrium moisture content of European spruce with lower specific gravity after the prolonged storage was rather higher than that of European maple with higher specific gravity. The specific gravity of spruce increased with decreasing annual ring width, however, that of narrower annual ring. Increasement in specific gravity enhanced the dynamic Young's modulus of both wood species, but influenced the vibration energy loss by internal friction differently between two species. For dynamic MOE, qurater-sawn spruce was higher than the flat-sawn, but maple showed the reverse directional characteristics. Consequently, it would be well for violin makers to establish the standard for materials and quality control system to assure the quality of their violin products.

• Journal of the Korean Wood Science and Technology
• /
• v.31 no.3
• /
• pp.11-16
• /
• 2003

On nitrobenzene oxidation of aspen, spruce, and knauf wood meals gave rise to vanilline, syrigaldehyde, p-hydroxybenzoaldehyde, vanillic acid, and other minor oxidation products. The phenolic aldehydes (p-hydroxybenzaldehyde, vanilline, and syringaldehyde) are derived from oxidative degradation of the corresponding 4-hydroxyphenylpropane units and their ethers. The lignin content of knauf wood meals was different as the concentration of NaOH solution and cooking temperature. The lignin contents of aspen, spruce, and knauf wood meals were decreased as laccase treatment. The laccase caused C-oxidation, demethylation, cleavage in phenolic groups and C-C cleavage in syrigyl structures.

• Journal of the Korean Wood Science and Technology
• /
• v.29 no.1
• /
• pp.52-59
• /
• 2001

The fixation characteristics of CCA and CCFZ in Japanese red pine, Japanese larch, and ezo spruce sapwood were compared at various temperatures and fixation conditions (drying and nondrying fixation). Fixation was monitored by the rates of reduction of hexavalent chromium to trivalent one, and optimal fixation time was estimated based on the results. The rate of fixation was highly temperature dependent, and the fixation rate of treated wood conditioned under nondrying conditions was much more faster than that under drying conditions, especially when the moisture content of treated wood was below fiber saturation point. Preservative types affected fixation; CCA-Type B had the highest fixation rate, followed by CCA-Type C and then CCFZ. The differences in fixation rates of preservative components were also observed among wood species; Japanese red pine fixed the fastest, followed by Japanese larch and then ezo spruce. Time required to complete fixation according to the fixation temperature could be predicted successfully using the regression equations between the temperatures and fixation time, regardless of conditioning methods, preservative types, and wood species.

• Journal of the Korean Wood Science and Technology
• /
• v.44 no.1
• /
• pp.135-146
• /
• 2016

Three fiber sources including Russian spruce (Picea jezoensis) and larix (Larix leptolepis), and Myanmar bamboo (Phyllostachys bambusoides) for thermomechanical pulp were explored to replace domestic pine (Pinus densiflora) pulp that has some limitations in an aspect of supply and pitch trouble. Thermomechanical pulps were manufactured under the identical condition, and then compared with their representative pulp properties and pulping process. Both Russian larix and Myanmar bamboo contained large amounts of extractives that would negatively affect mechanical pulping processes. Russian spruce showed the least contents in shives and pitch. Russian spruce and domestic pine reached an optimum freeness level within a short pulp processing time, which consumed less amount of refining energy compared to larix and bamboo. In particular, the spruce wood showed the highest brightness level which might lead to a less consumption of bleaching chemicals. It was expected that Russian spruce could be replaced with the domestic pine wood in respect of both pulping process and pulp quality.

• Journal of the Korean Wood Science and Technology
• /
• v.45 no.1
• /
• pp.20-27
• /
• 2017

The aim of this paper is to present the modulus of elasticity of $E_L$, $E_R$, $E_T$ along three principal axis of softwood dimension lumber by nondestructive method. Ultrasonic measurement was carried out on defect free wood samples taken by the Japanese Larch, SPF (spruce-pine-fir) and Hem-fir $2{\times}4s$. The ultrasound velocities were measured to calculate young's moduli and it was derived elastic constants for each wood samples using the ultrasound velocities and densities of wood. From the test, $E_L$ was much greater than $E_R$ and $E_T$. $E_R/E_T$ ratios were about 1.3. The high density wood had high young's moduli in three principal axis and the difference in young's moduli between species was greater in transverse direction than longitudinal direction. The anisotropy of the lumber was presented through the calculated elastic moduli and compliances matrix in diagonal term were determined by inverting the stiffness matrix.