• Journal of the Korean Wood Science and Technology
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• v.37 no.6
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• pp.546-555
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• 2009

To study an effective use of woods, three-ply hybrid laminated woods instead of crosslaminated woods which are composed of spruce in the face and three kinds of wood-based boards (MDF, PB, OSB) in the core were manufactured, and the effect of constitution elements for the core laminae on bending strength performances was investigated. Bending modulus of elasticity (MOE) of hybrid laminated woods had the highest values for the hybrid laminated wood types arranging OSB laminae in the core, and had the lowest values for those arranging MDF laminae in the core. These values were higher than those of various cross-laminated woods. The estimated bending MOEs of the hybrid laminated woods which were composed of perpendicular-direction lamina of spruce in the faces were similar to their measured values, regardless of wood-based boards in the core. However, those of the hybrid laminated woods which were composed of parallel-direction lamina of spruce in the faces had much higher values than those of their measured values, and it was necessary to revise the measured values. Bending modulus of rupture (MOR) of the hybird laminated woods had the highest value for those arranging OSB laminae in the core, and had the lowest values for those arranging PB laminae in the core unlike the bending MOE. By hybrid laminating, the anisotropy of bending strength performances was markedly decreased, and the differences of strength performances among wood-based boards were also considerably decreased.

• Applied Chemistry for Engineering
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• v.32 no.2
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• pp.197-204
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• 2021

This study investigated the smoke risk assessment of woods and plastics for construction materials, focusing on the smoke performance index-V (SPI-V), smoke growth index-V (SGI-V), and smoke risk index-VI (SRI-VI) according to a newly designed methodology. Spruce, Lauan, polymethylmethacrylate (PMMA), and polycarbonate (PC) were used for test pieces. Smoke characteristics of the materials were measured using a cone calorimeter (ISO 5660-1) equipment. The smoke performance index-V calculated after the combustion reaction was found to be 1.0 to 3.4 based on PMMA. Smoke risk by smoke performance index-V was increased in the order of PC, Spruce, Lauan and PMMA. Lauan and PMMA showed similar values. The smoke growth index-V was found to be 1.0 to 9.2 based on PMMA. Smoke risk by smoke growth index-V increased in the order of PMMA, PC, Spruce, and Lauan. COpeak production rates of all specimens were measured between 0.0021 to 0.0067 g/s. In conclusion, materials with a low smoke performance index-V and a high smoke growth index-V cause a high smoke risk from fire. Therefore, it is understood that the smoke risk from fire is high. It is collectively summarized by the smoke risk index-VI.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.191-195
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• 2006

Multivariate data analysis tools were used to improve the understanding of the wet end chemistry and white water system of the Papermill at NorskeCanada Crofton Division. Specifically, the analysis was aimed at identifying what variables were contributing to increased retention aid use and wet end instability. Several models were developed using data sets with up to 88 process variables and over 3000 observations. It was found that increased retention aid use was driven primarily by PCC and TMP usage as well as the addition of Alaskan White Spruce to the TMP furnish.

• Journal of Korean Society of Forest Science
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• v.81 no.2
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• pp.177-182
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• 1992

Soil air $CO_2$ concentrations were measured in two soil depths (O and B horizon) by (1) the use of the Draeger direct reading chromatographic tubes and (2) syringe gas collections with gas chromatographic detection in a Spodosol supporting low elevation, commercial spruce-fir forest, Maine, USA, Mean soil air $CO_2$ concentrations(%) during the growing season of 1991 ranged from 0.11 in the O horizon by the Draeger method to 0.29 in the B horizon by the gas chromatographic method. Soil air $CO_2$ concentrations by the Draeger method were lower than those obtained using the gas chromatographic method for both soil horizons. However, data from the two methods were significantly(p<0.01) correlated and paralleled each other relative to temporal patterns. Positive and highly significant correlations existed between soil air $CO_2$ concentrations and soil temperature, although correlation coefficients only ranged from 0.13 to 0.32, depending on the method and horizon chosen.

• Journal of Korean Society of Forest Science
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• v.97 no.2
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• pp.187-195
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• 2008

Picea jezoensis (Sieb. et Zucc.) Carriere is one of the major and widespread components of the cold-temperate and boreal forests in Russian Far East, northeast China, Korea, and Japan. However, it is restricted to a highly fragmented range in South Korea with small populations. Mean expected heterozygosity $(H_e)$ based on 22 loci in 11 isozyme systems was 0.077 for four sampled populations that covered the whole distribution range of P. jezoensis in South Korea. This value is within the range reported for conifers, but it is very low compared to that of other spruce species as well as that of P. jezoensis populations in Russian Far East. Most populations had a slight excess of heterozygotes and the Wright's $F_{IS}$ (-0.019) was comparable to that previously reported for other spruce species. In all of the four populations, the Wilcoxon sign-rank test indicated no greater heterozygosity than that expected for populations at mutation-drift equilibrium, suggesting that the populations have not been bottlenecked recently. Despite a fragmented range and isolated populations, population differentiation was not high $(F_{ST}=0.047)$ and the number of migrants per generation was 5.09. Nei's genetic distances were also small $({\bar{D}}=0.005)$ but strongly related to geographic distances between populations, suggesting an Isolation by Distance. The northernmost isolate, Mt. Gyebang population was genetically distinct from the other three populations. Implications for the conservation of genetic variation of P. jezoensis in South Korea were discussed.

• Journal of the Korea Furniture Society
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• v.21 no.6
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• pp.499-504
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• 2010

Korean traditional buildings, Hanok, are mostly constructed with dimension lumbers and roundwoods. They are hardly kiln-dried without severe defects, thus usually air-dried from some months to an year. Dimension lumbers and roundwoods were heat-treated above $170^{\circ}C$ and drying defects were examined. Temperature rising curves of all dimension timbers used for this study show one or two deflection points. The time when the temperature at 37.5mm depth reached at $100^{\circ}C$ for spruce dimension heat-treated at $170^{\circ}C$ was twice longer than that heat-treated at $190^{\circ}C$. There were many internal checks in roundwoods of $148mm{\Phi}$, while surface checks were apparently closed at the end of heat treatment. The drying time of $300{\times}300mm$ dimensions with 65mm hole was shorter than that without hole by half.

• Korean Journal of Plant Taxonomy
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• v.42 no.1
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• pp.80-90
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• 2012

While preparing a floristic study of Korean hepatics, we discovered the following 10 unrecorded species from Mt. Jiri-san (maximum height, 1,915 m) and Mt. Seorak-san (maximum height, 1,708 m): Neotrichocolea bissetii (Mitt.) S. Hatt., Calypogeia angusta Steph., Cephaloziella massalongii K. Mller, Harpanthus scutatus (F. Weber & D. Mohr) Spruce, Plectocolea torticalyx (Steph.) S. Hatt., Anastrophyllum michauxii (F. Weber) H. Buch, Lophozia excisa (Dicks.) Dumort., Lophozia lantratoviae Bakalin, Mylia verrucosa Lindb., Scapania sphaerifera H. Buch. They are distributed near streams and/or on the top of a ridge on Mt. Jiri-san and Mt. Seorak-san.

• Journal of the Korean Wood Science and Technology
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• v.35 no.5
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• pp.7-15
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• 2007

To evaluate the durability of finger-jointed woods according to change of humidity conditions, four types of finger-jointed woods glued with different kinds of adhesives and finger pitches were made with Sitka spruce, and the effect of humidity conditions on creep performances was investigated. The shape of creep curves differed among humidity conditions, and the inclination of creep curves was greatest in 85%RH, and lowest in 65%RH. Their creep curves showed a linear behavior beyond approximately one hour, regardless of humidity conditions. The A values of the creep curves fitted to power law increased with increasing relative humidity, whereas the A' values were in order of 30 > 85 > 65%RH unlike the A values. The initial deformation increased with increasing relative humidity, whereas the creep deformation unlike the initial deformation was in order of 85 > 30 > 65%RH, and it was found that the creep deformation of finger-jointed woods indicated the smaller amount in air-dry moisture content rather than in a low moisture content less than 30%RH. Finger-jointed woods with 6.8 mm (L) pitch had the greater creep amount than in those with 4.4 mm (S) pitch in all humidity conditions. The difference of creep amount between both adhesives in all humidity conditions was small. Relative creep at 240 hr was greatest as 62.2~71.9% in 85%RH, and the values indicated 2.1~2.6 times that of 30%RH and 3.0~3.6 times that of 65%RH and were equal or slightly greater than that of solid spruce.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 1999.04b
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• pp.254-258
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• 1999

The distribution of anionic groups in the fibers, the fines, the colloidal fraction and the dissolved fraction, respectively, of thermomechanical pulp (TMP) suspensions was determined and peroxide bleaching of spruce TMP were also studied. Spruce TMP was extracted with hexane, treated with alkali, or bleached with peroxide. Suspensions made at pH 5.5 were fractionated into long fibres, large fines, small fines, a colloidal fraction and a dissolved fraction. The charge of the fractions was determined using polyelectrolyte titration. To determined the origin of the charges, the contents of fatty acids, resin acids and acidic units in hemicelluloses in the different fractions were determined by has chromatography. Extraction of TMP with hexane prior to fractionation increased the measured charge of the fibres. The removal of the wood resin probably uncovered some carboxyl groups on the fibre surfaces, or improved th e penetration of polybrene into the pores of the fibres. The charge of the fines and the colloidal fraction was lower when the wood resin had been removed. Alkaline treatment of the TMP increased the charge of the fibres and fines, mainly because of demethylation of pectins. Alkaline treatment increased the charge also of the dissolved fraction, because of the release the charge also of the dissolved fraction, because of the release of pectic acids into the water phase. Alkaline peroxide bleaching further increased the charge of fibres and the dissolved fraction, most likely because of lignin oxidation. The charge of the colloidal fraction, consisting mainly of wood resin, was only slightly affected by alkaline treatment and peroxide bleaching. The anionic groups in TMP suspensions were mainly free uronic acids in the hemicelluloses. The contribution from the fatty and resin acids was substantial only for the colloidal fraction.

• Plant Biotechnology Reports
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• v.2 no.4
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• pp.259-265
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• 2008

Picea koraiensis, called Korean spruce, is an evergreen tree and found mostly in northeast Asia. In this study, plant regeneration via somatic embryogenesis from open-pollinated immature zygotic embryos of nine geno-types of elite trees was established. Immature zygotic embryos were cultured onto RJW medium modified from 505 medium with $21.48{\mu}M$ NAA, $2.22{\mu}M$ BA, and $2.32{\mu}M$ KT. The average frequency for all nine genotypes was 74.2%. Embryogenic calluses of the nine genotypes of elite trees were subcultured on RJW basal medium containing $8.06{\mu}M$ NAA, $1.11{\mu}M$ BA, and $1.16{\mu}M$ kinetin. The calluses of three lines, $3^{\sharp}$, $9^{\sharp}$, and $2^{\sharp}$, were actively proliferated but others were not. Somatic embryogenesis was induced from the embryogenic callus in genotypes of $3^{\sharp}$, $9^{\sharp}$, and $2^{\sharp}$ on RJW medium with ABA and $60g\;l^{-1}$ sucrose. Cotyledonary somatic embryos were subjected to a drying process. The drying of embryos by uncapping the culture bottle for 5 days on a clean bench resulted in a high frequency of germination of somatic embryos (87% in RJW medium). However, plantlet conversion from germinated embryos was greatly reduced and the optimal medium for plant conversion was 1/2 WPM or 1/2 BMI medium. In conclusion, we have, for the first time, established a plant regeneration system via somatic embryogenesis in the Korean spruce, which can be applied for rapid micropropagation of elite trees.