• 한국생물공학회:학술대회논문집
• /
• 2003.04a
• /
• pp.467-470
• /
• 2003

The endoxylanase (642 bp; 213 amino acids) and ${\beta}-xylosidase$ (1,602 bp; 533 amino acids) genes from Bacillus sp. were amplified by PCR and separately inserted downstream of the yeast ADH1 promoters, resulting in the pAEDX-1 and pAEX plasmid. When the yeast transformants, S. cerevisiae SEY2102 harboring pAEDX-1 or pAEX, were grown on YPD medium, the total activities of the enzymes reached about 9.8 unit/mL for endoxylanase and 2.9 unit/mL for ${\beta}-xylosidase$. When the three kinds of xylan from oat spelts, birch wood, and corncob were hydrolyzed by treatment of recombinant endoxylanase and ${\beta}-xylosidase$, it was found that xylose, xylobiose and xylotriose were produced and xylose was the major product after 12 h reaction. In addition, with the higher amount of enzymes, the more amount of xylose was produced.

• Journal of the Korean Ceramic Society
• /
• v.41 no.2
• /
• pp.158-164
• /
• 2004

This study is to analyze the characteristics of typical Korean wood ashes from twelve trees, oak tree needles and pine bark, which are common in the area, and to suggest their applications in ash glaze making. The chemical analysis of the ashes shows that the main component of wood ash is CaO while wood bark ash consists of $SiO_2$, and leaf ash consists of CaO and $SiO_2$. The results of the study are as follows: Ashes made from the wood of Acasia, Popular and Jujube contained relatively high amounts of Fe$_2$ $O_3$ and MgO compared to other tree ashes. The ashes had yellowish green color glaze. From the result of W analysis they presented the highest chroma. Therefore these ashes are good for making transparent glaze. From the result of W analysis Grapevine, pear and oak wood ashes containing the highest amounts of Fe$_2$ $O_3$, MgO, P$_2$O$\_$5/ and MnO presented yellowish green color glaze compared to other ashes are suitable for making opaque glazes because of their showing stable and opacity phenomena. Pine tree, Platanus and Zelkova wood ashes consist of high amounts of CaO and P$_2$O$\_$5/ compared to other tree ashes. So they showed the most vivid and bluish green color glaze among 12 ashes. Therefore, they would make a good celadon glaze. Birch, oak and chestnut tree ashes have high content or MnO which affects on glaze color with small amount. These ashes presented yellowish green color not as much strong as Acacia ash, Poplar ash, Jujube tree ash. These are good for Irabo glaze.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.5 no.1
• /
• pp.21-24
• /
• 1999

The analysis of hazard compounds, including naphthalene, biphenyls (BP) and diethyl phthalate (DEP), was conducted from the wooden kitchenwares and sanitory produce. Fifty samples of that wooden products in the local market were purchased for the study. All the samples were extracted by benzene and n-heptane, followed by the analysis through GC-MSD. As a result, neither naphthalene nor diethyl phthalate were found, however, trace amount of biphenyls were detected on all the samples ranged from 0.1 to 3.1 ppm. Biphenyls also contained both in the imported and the domestic of White Birch wood, as 0.25 ppm and 0.34 ppm, respectively. The concentration of biphenyls reduced with the process of the original woods, and especially the detection range was relatively low compared with the permission one of apples (110 ppm). The results suggested that biphenyls were contaminated into the product not by the addition doting the process of manufacture, but as the component itself in raw wood materials. Also, the content of the residual biphenyls were not suspected to give the harmful effects.

• Journal of the Korean Wood Science and Technology
• /
• v.35 no.6
• /
• pp.159-165
• /
• 2007

An extracellular xylanase from the brown-rot fungus Fomitopsis palustris grown on rice straw culture was purified to a single protein band. On SDS-PAGE, the molecular mass of purified enzyme was estimated to be about 43 kDa. The amino acid sequence of the proteolytic fragments showed high homology with fungal glycoside hydrolase family 10 xylanases. The $K_m$, $K_{cat}$ and $V_{max}$ for birch xylan were $31mg/m{\ell}$, $2.3{\times}10^4/min$ and 252.3 U/mg, respectively. The optimal activity of the purified xylanase from F palustris was observed at pH 4.0~5.0 and $70^{\circ}C$.

• Korean Institute of Interior Design Journal
• /
• v.13 no.6
• /
• pp.140-149
• /
• 2004

The bentwood technique was introduced for the Windsor chair for the first time in the 18th Century. It was Michael Thonet who produced the bentwood chair in Austria around the 1870's, and it has changed the perception of architects and designers since then. The bentwood chair suggested a new and eccentric way of manufacturing furniture and the process of producing materials for it. Moreover, the method of furniture assembling, with screw nails, made a positive contribution not only to the convenience of transport and distribution of furniture to anywhere in the world, but also to the development of mass production of furniture for the multitudes. The bentwood technique of Michael Thonet was developed much further by Alvar Aalto, who inferred a soft curve from nature and developed the beauty of modern laminated bentwood by using birch, a plentiful resource of Finland. This study will help us to understand the functions and process of bentwood furniture, and help to develop technical skills for diverse furniture design. It will also confirm that diverse bentwood furniture design will be possible by applying materials, technical skills and the design process of bentwood according to the characteristics and concept of furniture design.

• Journal of Korean Society of Forest Science
• /
• v.94 no.5 s.162
• /
• pp.321-329
• /
• 2005

Based on the data representing four typical Korean pine forest types, the age structure, DBH distribution, species composition, and forking rule were systemically analyzed for old-growth Korean pine forest in Liangshui Nature Reserve, northeast China. The age structure of Korean pine trees was strongly uneven-aged with one dominated peak following normal distribution, and age of trees varied from 100 to 180 years within a stand. The DBH and height differences in same age class (20 years) varied from 28 cm~64 cm and 5 to 20 m, respectively. Many conifer and hard wood species, such as spruce, fir, costata birch, basswood, oak, and elm, were mixed with dominated trees of Korean pine. The canopy of the old-growth Korean pine forest can be divided into two layers, and differences of mean age and height between Layer I and Layer II were ranged 80~150 years and 7~13 m, respectively. The Weibull function was used to model the diameter distribution and performed well to describe size-class distribution either with a single peak in over-story canopy and inverse J-shape in under-story canopy for old-growth Korean pine stands. The forking height of Korean pine trees ranged from 16m to 24 m (mean 19.4 m) and tree age about 120 to 160 years old. The results will provide a scientific basis to protect and recover the ecosystem of natural old-growth Korean pine and also provide the model in management of Korean pine plantation.

• Journal of Korean Society of Forest Science
• /
• v.45 no.1
• /
• pp.62-67
• /
• 1979

Ultraviolet microscopy of ultrathin sections of wood has proved to be one of the useful means for determining the lignin distribution in the various regions of the cell wall. Also, spectral approach and quantitative analysis of isolated compound middle lamella fraction from birch xylem have revealed that the lignin associated with the vessel secondary wall and middle lamella is composed predominantly of gualacylpropane units. Lignin deposited in the fiber and ray parenchyma secondary walls is composed mostly of syringylpropane units. The middle lamella lignin around fibers and ray cells contains both guaiacyl and syringyl propane quits. On the basis of the results above, this research was carried out to clarify the origin of milled wood lignin (MWL) by analysing the chemical characteristics of ML MWLs extracted at various milling stages. The amount of phenolic hydroxyl-, ${\alpha}$-carbonyl-, and methoxyl-group in the MWL's increases the milling time. And progressive mining contributes to the merease of ratio of syringylaldehyde to vanillin(S/V ratio) after nitrobenzene oxidation of MWL. Accordingly, It could be concluded that milled wood lignin extracted at the initial milling stage derives from compound middle lamella region of cell wall, whereas, with progressive milling, lignin of secondary wall of fiber is introduced gradually to milled wood lignin. These results are suggesting that heterogeneous chemical structure of lignins in hardwood exists. Although milled wood lignin at the initial stage seems to have lower molecular weight in comparison with milled wood lignin extracted at final milling stage from the result of Gel-filtration curves, further study would be required on molecular weight distribution of milled wood lignin in future.

• Korean Journal of Food Science and Technology
• /
• v.44 no.1
• /
• pp.114-120
• /
• 2012

The purpose of this study was to evaluate the antibacterial activities of chopping boards made of various materials such as three antibiotic plastics, a general plastic, and various woods (red pine, rubber tree, cypress, birch, and bamboo) using zone inhibition assay and real-time PCR. Wood chopping boards showed high antimicrobial activity against Vibrio vulnificus, while plastic chopping boards showed high antimicrobial activity against Escherichia coli O157:H7, Salmonella Typhimurium, and Staphylococcus aureus. Bamboo chopping board among the wood chopping boards showed the highest antimicrobial activity against five foodborne bacteria such as E. coli O157:H7, S. Typhimurium, Vibrio cholerae, and V. vulnificus. These results may be helpful in the selection of a chopping board with high antimicrobial activity and in the application of hygiene procedures for prevention of cross-contamination.

• Journal of the Korean Wood Science and Technology
• /
• v.10 no.3
• /
• pp.118-131
• /
• 1982

1. In order to investigate the effect of variation of assembly time on glue bond strength, and to determine the optimum range of assembly time with given glue, this experiment was made at the suggestion of the Wood Technology Laboratory, School of Forestry, Yale University. 2. For this investigation, three-ply-plywoods with 1/22 inch, birch veneer, phenolic resin, and soybean glue were made at the following variation of assembly time, that is, 1, 5, 10, 25, 35, 50, and 70 minutes, under both open and closed assembly manners, and the shear strength test at dry and wet were adoptted. 3. The shear strength and wood failure of each plywood panel constructed at the given assembly time have been illustrated in Tables 1, 2, 3 and 4. It has shown that there is a remarkable tendency, for increasing assembly time to give lower shear strength and wood failure throughout almost all cases. The effective range of assembly time of tested glues in this investigation for both open and closed assembly are summarized in the Table 7. Thus, allowable assembly time for Phenolic resin may be up to 10 minutes under open assembly and up to 50 minutes under closed assembly. For soybean glue, the permissible assembly time may be up to 5 minutes under open assembly and up to 15 minutes under closed assembly. The allowable assembly time for open assembly with the same glue is reduced by approximately one third or more than one third as compared with closed assembly time. This might mean that the closed asembly time for these glues is more practical than the open assembly.

• Korean Institute of Interior Design Journal
• /
• v.13 no.5
• /
• pp.162-172
• /
• 2004

Architects and designers of the 20th Century made various efforts to establish new design languages reflecting the changes of society, the times, and environment. They used furniture, especially chairs, as controversial items of aesthetic value, society and ideology. Le Corbusier and Alvar Aalto are furniture designers as well as architects, who adopted this ‘spirit of the times’ actively and have greatly contributed to modernism. This study will help us to understand the diversity of design since modernism, by comparing these two designers' furniture design. It also covers the common factors In modern furniture design, and analyses their individuality and likeness In design. The following is a comparison of furniture design by Le Corbusier and Alvar Aalto. Le Courbusier linked International design and Aalto linked Rational design and Organic concept design to their furniture, just as they did in their architecture. They were able to establish the base of modern furniture design by adapting new concepts and pursuing humanism. In structure, Le Corbusier's furniture Is simple and proportional. It demonstrates a sophisticated geometric composition, mechanical beauty. On the other hand, Aalto rationally linked nature with human requirements and his furniture is organic and in harmony with geometric structure. In function, Le Corbusier's furniture is standardized and prefabricated. He designed for the user so they could choose to use the furniture efficiently to suit their needs. In comparison with Le Corbusier, Aalto Invented the ‘Stacking Chair’ which allows a more effective use of space and reflected the structure of the human body to improve the user's comfort. In materials and techniques, Le Corbusier used new materials like metal or leather, and attempted new ways such as welding, prefabrication, and standardization for production. On the contrary, Alto mainly used birch, which is the traditional material in Finland, and tried new bent wood techniques and joining methods.