• Journal of the Korean Wood Science and Technology
• /
• v.19 no.1
• /
• pp.31-63
• /
• 1991

It was proved that in conventional kiln drying of disks piling position in the kiln exerted a great influence on drying rates, and the larger the variation of disk diameter, the more undulating drying rates of disks. While in vacuum drying disks there was no influence on drying rates. By the end-wrapping treatments and the radial direction of disks tangential surface stresses in the core of disks were slightly compressive in three species. In control disks the drying stresses distributed into one step-style that compressive stresses in the pith side of 6cm from pith were larger than those in the bark side, while in the disks end-wrapped with Korean paper the drying stresses distributed uniformly, because flow rates of free water in disks had no difference between heart-and sap-wood by obstruction of evaporating water from surface of disks by end-wrapping with Korean paper. And end-wrapping with Korean paper considerably restrained those. Tangential differential shrinkage stresses developed the maximum tensile stress near the bark and with approaching the pith the stresses gradually reduced and changed into compressive stresses in near the pith. At the end of vacuum drying the maximum tangential tensile stresses of disks end-wrapped with Korean paper were smaller than those of control disks, and critical moisture contents causing the V-shaped crack of disks end-wrapped with Korean paper were lower than those of control disks because of the set by obstruction of evaporating water of end-wrapping with Korean paper. In the experiment of vacuum drying stress distribution the disks end-wrapped with Korean paper or aluminum foil in three species were free from V-shaped cracks and control disks were defected very slightly by V-shaped cracks. And also disks end-wrapped with Korean paper were free from heart checks in Alnus japonica and Juglans sinensis, and heart checks were occurred very slightly in others. Especially, not to speak of disks end-wrapped with Korean paper, vacuum drying of disks end-wrapped with aluminum foil prevented effectively drying defects, moreover drying times could be shortened, that is. Ginkgo biloba, Alnus japonica, and Juglans sinensis disks could be dried from green to in-use moisture content in 110 hours, 272 hours, and 407 hours, respectively.

• Asian Journal of Turfgrass Science
• /
• v.15 no.2
• /
• pp.51-64
• /
• 2001

Summer stress is one of the serious problems on cool-season grass at the soccer fields in Korea during heavy rainy season. This study was conducted to intestigate the effect of shade net with regard to its percent (0, 50, 75), color (black, green), height (0 cm, 30 cm) and time (7 hr, 24 hr) on turf canopy temperature, light intensity, leaf color, turf performance, clipping yield and root dry weight of cool-season turfgrass. Turf canopy temperature was 6~13$^{\circ}C$ under black and green shade net when temperature was over 4$0^{\circ}C$. Light intensity was also decreased from 40 to 94% under black and green shade net compared to control. Black shade net was more effective than green net in reduction of temperature and light intensity. Green shade net was found to be better for photosynthesis of cool-season grass. Leaf color, turf performance, clipping yield, and root dry weight were better and increased under 50% and 75% shade net. 50% black shade net with 30cm height and 7 hr treatment showed the best turf performance. It can be concluded that 50% and 75% green shade net can be used fur reducing summer stress on cool-season grass after soccer marches during heavy rain season. The shade net decreased the turf canopy temperature and reduced heating damage of cool-season turfgrass.

• Korean Journal of Weed Science
• /
• v.15 no.2
• /
• pp.166-174
• /
• 1995

This experiment was conducted to investigate a cause of summer depression of cool season turfgrass, using nine cultivars in warm season and twenty-eight cool season turfgrasses. Even though an average of apparent photosynthesis(APS) per fresh weight was 13.09 mg $CO_2$/g/h in warm season turfgrass and 7.75 mg $CO_2$/g/h in cool season turfgrass, the Creeping bentgrass in cool season type was higher than Kikuyugrass and Bahiagrass in warm season type. The optimum temperature for the heighest APS was $30^{\circ}C$ in warm season type and $25^{\circ}C$ in cool season type. In $CO_2$ compensation point(CCP) as an index of dark respiration, it was higher in cool season turfgrass(75.6ppm) than warm season turfgrass(29.5ppm). In warm season type, even though the temperature increased from $25^{\circ}C$ to $40^{\circ}C$ the CCP was not increased. But the higher temperature rises the more increased CCP in cool season type. Dark respiration(DR) was higher in cool season type than warm season type under various temperature conditions, but the increasing ratio of DR with the temperature increment was not so much differed between two types.

• Food Science and Preservation
• /
• v.15 no.5
• /
• pp.635-641
• /
• 2008

This study was conducted to investigate the optimal sub-zero temperature for storage of two garlic cultivars, the northern ecotype 'Jaerae' and the southern ecotype 'Daeseo'. These cultivars of garlic bulbs were stored at different temperature (room temperature, $0^{\circ}C$, and $-4^{\circ}C$) conditions after predrying. Southern ecotype garlic showed higher weight loss than northern ecotype garlic. Northern ecotype garlic at $-4^{\circ}C$ exhibited less than 5% of weight loss during 10 month storage. Sprouting rate was higher in southern than in northern ecotype at room temperature storage. The value of injury by disease and insect was similar between southern ecotype and northern ecotype for 5 month storage, and then northern ecotype showed higher value of injury by disease and insect than southern ecotype. Hunter 'b' value of northern ecotype garlic was the lowest at $-4^{\circ}C$ storage. Northern ecotype garlic showed no cold injury at freezing point temperature storage. However, southern ecotype garlic had $0{\sim}5.3%$ cold injury occurrence at $-4^{\circ}C$ storage. Respiration and ethylene production exhibited the highest at room temperature storage, those had the slight increase at $0^{\circ}C$ and $-4^{\circ}C$ storages. Northern ecotype showed higher enzymatic pyruvic acid and fructan contents than those of southern ecotype. Enzymatic pyruvic acid content increased and fructan contents decreased during storage time.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2010.04a
• /
• pp.95-102
• /
• 2010

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
• /
• 2011.10a
• /
• pp.307-313
• /
• 2011

• Journal of the Korean Wood Science and Technology
• /
• v.37 no.4
• /
• pp.414-420
• /
• 2009

We dyed traditional Korean hand-made papers (Hanji) with colorants extracted from fruits of Alnus japonica to investigate the effect of various dyeing factors (mordant, dye concentration and dyeing assistant) on colors, K/S values and light fastness of the dyed Hanji. The dyed hanji had brown color. The K/S value of dyed Hanji was increased by mordanting with alum and copper acetate. $a^*$ and $b^*$ value of dyed Hanji was decreased slightly by mordanting with alum and Iron(II) chloride. The K/S value and $b^*$ of dyed Hanji increased with increasing concentration of dye, but $L^*$ value of dyed Hanji decreased. The K/S value of dyed Hanji was also increased by fixing agent. When Hanji was mordanted with Iron(II) chloride and was not mordanted, use of fixing agent resulted in greater increase of K/S value. Use of fixing agent resulted in poor light fastness. When fixing agent was used, mordanting with copper acetate resulted in smaller color difference than mordanting with alum after aging test.

• Journal of Korea Foresty Energy
• /
• v.22 no.3
• /
• pp.43-48
• /
• 2003

Black liquor staining for the development of natural color of bleached Hanji caused problems of discoloration and degradation. This study was carried out not only to complement these problems but also to develop natural dyeing method that was similar to the color of unbleached Hanji, through the dyeing of rice straw extractives. The dyeing properties of Hanji were influenced more by dyestuffs extraction method than extraction and dyeing time. Dyeing ability of hot water extractives was superior to cold-water extractives. Without the relation to the time of extraction and dyeing, the color of Hanji dyeing hot water extractives were similar to the control, and the color of Hanji dyed for 45 min with hot water extractives that extracted for 120 min, were almost same as the control. As natural dyestuffs, hot water extractives of rice straw showed that excellent dyeing ability for the development of various natural colors similar to unbleached Hanjis.

• The Journal of the Convergence on Culture Technology
• /
• v.8 no.3
• /
• pp.83-89
• /
• 2022

For the purpose of promoting the excellence of Korea's unique traditional hanji around the world, it was intended to promote 'modernization of tradition' by producing and presenting cultural products suitable for modern sensibility using traditional hanji which is widely used in the arts. First of all, using hanji as a material, jumchi hanji was made by jumchi technique. Cut to a certain width according to the cultural products such as laptop case, cell phone case, hat, and bag. Weave the cut jumchi hanji with plaine weave, twill weave, and hexagon depending on the purpose of the cultural products to be made. A cultural products were made by matching the woven jumchi hanji with artificial leather, cotton, and denim.

• Journal of Korea Foresty Energy
• /
• v.23 no.1
• /
• pp.38-44
• /
• 2004

The application of the dispersant is indispensable to the manufacture of Korean traditional paper (Hanji). However the mucilage of which extracted from Abelmoschus manihot root has viscosity drop problem in summertime and synthetic dispersant such as polyacrylamide (PAM) and polyethyleneoxide (PEO) have some problems that under the influence of the quality of. water, cohesion, and bad solubility. This study was carried out not only to develop new natural dispersant that can solve such problems but also to investigate the viscosity and papermaking characteristics of Hydrangea paniculata mucilage. There were no viscosity changes between control and treated mucilage that adjusted to pH 9, heated 6 hours at 40 $^{\circ}C$, and stored heating treatment one for a week at 5 $^{\circ}C$. The treatment of mucilage that adjusted to pH 9 and aged for 120 hours at 4$0^{\circ}C$ resulted in viscosity drop. In the hydrolysis of mucilage, galacturonic acid and glucuronic acid contents were decreased by heating and pH adjusting treatments. Wet web stripping quality and physical properties of Korean traditional paper, which used Hydrangea paniculatamucilage were same or superior to the Abelmoschus manihot root.