• 보존과학연구
• /
• s.31
• /
• pp.89-102
• /
• 2010

This study evaluated the activity of biocidal compounds isolated from natural products and confirmed applicable possibility as conservative agents for orgainic cultural heritages damaged by biological degradation. we used methanol extracts of 11 Korean trees and 17 medicinal plants as natural resources. Among these extracts, Phellodendron amurense was investigated on antifungal activity against Coniophora puteana, Lentinus lepideus, Tyromyces palustris and Aspergillus niger. Asarum sieboldii was investigated on insecticidal activity against adult of Lasioderma serricorne. First, the extract of Phellodendron amurense was partitioned into hexane, dichloromethan and ethylacetate fraction. Among them, the ethylacetate fraction had the most significant antifungal activity. In addition, Asarum sieboldii essential oil showed an effective antifungal and insecticidal activity. As a result, the extract of Phellodendron amurense and Asarum sieboldii essential oil could be useful for conservation of organic cultural heritage against biological deterioration by wood rot fungi and Lasioderma serricorne.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.42 no.2
• /
• pp.46-52
• /
• 2010

The annals of Joseon Dynasty has been known as one of the UNESCO's Memory of the World Heritage. The annals of Joseon Dynasty composed with two kind of books, wax coated book and non coated book. Especially the waxed book have been severely damaged by various reason. For the safety preservation of the annals of Joseon Dynasty waxed book, the thermal ageing mechanism of beeswax coated Hanji paper has been evaluated. The weight loss of waxed Hanji were rapidly increased until 30 days in three temperatures(105, 120 & $150^{\circ}C$) and stabilized after 30 days. The acid value and relative intensity of carbonyl groups in beeswax were increased with strong conditions. This means that the deterioration of beeswax should be progressed with oxidizing reaction. The physical strength and the crystallinity of dewaxed Hanji were decreased with ageing time.

• Journal of the Korean Wood Science and Technology
• /
• v.14 no.3
• /
• pp.36-42
• /
• 1986

The production media and the enzymatic charateristics of laccase from Flammulina velutipes were investigated. The activity of laccase during incubation reached to the maximum at the 40 days of incubation in the case of Barley straw medium. The maximum laccase activity in Barley straw medium was 5 and 16 times higher than those in Onion basic and Sawdust media, respectively. The laccase from Flammulina velutipes has the optimum pH of 6.6 and showed to be stable at relatively broad pH range. 4.5-9.5. Temperature stability showed that above 96% activity could be preserved after holding at 40$^{\circ}C$ for 40 minutes. At the above 70$^{\circ}C$, the laccase activity decreased very rapidly. The Km value of the laccase was estimated to be 28.0 mM which is much higher than that of the laccase from Pleurotus ostreatus. Organic solvents for precipitiation of the enzyme did not inactivation the laccase. Sodium azide which was added for preventing microbial deterioration affected significantly the inactivation of laccase, but this activity was recovered completely by precipitating the enzyme with acetone.

• Journal of Conservation Science
• /
• v.28 no.4
• /
• pp.395-401
• /
• 2012

To investigate bioactive materials for development of natural conservative agent on organic cultural heritage, essential oil from Asarum sieboldii was screened for antifungal and insecticidal activity against 4 wood rotting fungi and adult of Lasioderma serricorne. Antifungal activity of essential oil was tested by using paper disc soaking method. Antifungal activity expressed as $IC_{50}$ value showed $1.50{\sim}2.84{\mu}l/disc$ range and the most significant antifungal activity was observed in Lentinus lepideus. The insecticidal activity of essential oil was examined by topical application method against L. serricorne adults. 50% and 100% of essential oil gave 98.3% and 100% mortality for 24 hours, respectively. The major components of the essential oil were methyl eugenol (56.32%), eucarvone (11.53%), safrole (5.79%), ${\delta}$-3-carene (2.09%), which were identified by gas chromatography-mass spectrometry. From these results, essential oil from A. sieboldii could be useful for conservation of organic cultural heritage against biological deterioration by insect and wood rotting fungi.

• Conservation Science in Museum
• /
• v.4
• /
• pp.71-78
• /
• 2003

The wooden striker on the Divine Bell of King Seongdeok was examined to identify the species of the wood and the outdoor wood weathering caused by solar light, moisture, temperature and air. The species of the wooden striker was identified to Zelkova serrata. When observed the striker with naked eyes, the results were surface discoloration (graying), cracking and roughness. In order to examine the morphological changes according to deterioration type, the specimen were separated to three part(I, II,III-spot). The I-spot was discolored to gray and at the same time entirely covered with dust. So the observation was impossible. The II-spot was also discolored but its texture could be observed. On it could observe numerous fungal hypae and dirts like dust flown into the cell lumens. The cell wall has been so weakened by weathering that it lost the physical intensity. This have made microchecks and splits on the cell wall. Although fungal hypae covered the cell, they did not result in wood decay. The III-spot, located just 0.5 mm below the surface, was maintaining the natural red-brown color of the wood. Its cell wall was similar to that of sound wood. These changes are different from wood decay, and limited only to the surface of the striker-less than or equal to 0.5 mm below.

• Journal of the Korean Wood Science and Technology
• /
• v.36 no.1
• /
• pp.21-29
• /
• 2008

The deterioration of Korean traditional wooden house located in seoul was estimated. This house was attacked by termite. To estimate damage status of buildings, non-destructive methods were applied. Some of the post needed to be replaced due to low strength, estimated by nondestructive methods. The house was installed with boiler heating facility, to use office and public education. This kind of heating system changed the environmental condition of the wooden house. The termite which attacked the house was classified as Reticulitermes speratus. Because of durability of wooden house effected by environment, control of the environmental condition is essential for maintaining the wooden house. The installation of modern facility to traditional wooden house should not change the traditional structure and do not effect to durability of wooden house.

• Journal of Korean Association for Spatial Structures
• /
• v.9 no.3
• /
• pp.93-100
• /
• 2009

As interest in latest cultural heritance is increased, an importance about conservation of dilapidated cultural building asset is risen. Most of cultural building asset used wood by main material and conservation repair about corrosion and damage by deterioration of these cultural building asset considers cultural value of member and the basis principle is the archetype maintenance. Accordingly, conservation processing method that use synthetic is embossed. This paper experimented with reinforcement sectional area ratio, direction of section, length, strength of synthetic resins as variable and manufactures total 14 specimens as experimental study about compression reinforcement performance of circular section wood that strengthen by synthetic resins. The result of this paper has shown that adequate strengthen is more efficient than new member and the most important authenticity in strengthen and repair of cultural heritance can be ensured.

• Journal of the Korean Wood Science and Technology
• /
• v.15 no.4
• /
• pp.45-58
• /
• 1987

This study was carried out to improve the physical and mechanical properties of Pupulus alba $\times$ glandulosa treated by the heat and compression. The results obtained were as follows. 1. The specific gravity of the wood was conspicuously increased by the lincreasing of pressing level. 2. The shrinkage of the wood was increased. by the increasing of pressing level. The radial shrinkage was 6.41-8.81%, the tangential shrinkage was 8.98-19.81 %, and the longitudinal shrinkage was 1.46-1.91 %. Comparing to the untreated stock, the rate of increase was 48.7-104.4% in radial direction. 1.7-124.4% in tangential direction and 60.4-109.9% in longitudinal direction, respectively. 3. The rate absorption of 30% compressed stock was Similar to that of untreated stock. but the rate of absorption of 40 % or more compressed stock was increased highly. 4. The thickness swelling of the wood was not changed in radial direction at pressing level, but was conspicuously increased in tangential direction under the pressing level of 40% and 50%. 5. The heat and compression treatment affected on the mechanical properties of the wood. The longitudinal compressive strength was increased under the pressing level of up to 40%, but was decreased under the pressing level of 50%. The bending strength was not changed under the compression percentage of up to 30%, but was decreased under the pressing level of 30% or more. And, the absorbed energy in impact bending was increased to 128% under the pressing level of up to 30%, but was decreased under the pressing level of 30% or more. Conclusionly, the mechanical properties of the wood was improved by the heat and compression treatment, but the strength of the wood was decreased under the pressing level of a certain level or more(in this study, pressing level of 30% or more). This was because of the wood deterioration due to the deformation(shrinkage, crack, failure) of wood tissues induced by the heat and compression treatment, the heat analysis of wood components induced by the heating, and the drop of the degree of polymerization.

• Architectural research
• /
• v.15 no.1
• /
• pp.25-33
• /
• 2013

The amount of construction waste increased to 176,447 ton/day in 2008 from 28,400 ton/day in 2000, a 6-fold increase in just 10 years. Such dramatic increase in the waste of concrete, asphalt concrete, wood and metals was due to demolition of old buildings as well as a great number of building redevelopment projects and hurried city industrialization. Many buildings targeted for demolition today were built in line with the government policy to provide affordable housing to citizens in the shortest time possible and consequently, said buildings underwent rapid deterioration and required periodic repairs and reconstruction. Based on the above, we predict that construction waste will continue to increase for the foreseeable future. In particular, due to limited availability of suitable space to construct apartments and residential buildings in the city, old buildings are being torn down to make space for new development, further increasing construction waste. In light of that, efforts to recycle as well as reduce generated waste are urgently required.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2019.11a
• /
• pp.56-57
• /
• 2019

Recently, the risk of fine dust is emerging in Korea. According to the OECD report, the incidence of hospitalization and mortality from lung disease is increased, and the incidence of lung cancer and mortality from ischemic heart disease with prolonged exposure are increased. In addition, indoor air quality has become an important factor affecting the human body as indoor life has increased due to the Industrial Revolution. Air pollutants that cause indoor air deterioration typically include particulate dusts as described above, formaldehyde and VOCs released in gaseous form from adhesive wood products used in building materials and furniture. May cause breathing problems. In this study, we analyzed the properties of adsorption matrix for improving indoor air quality using cork.