Park J.-S.,Korea forest Research Institute |
Hwang K.-H.,Korea Forestry Promotion Institute |
Jeong G.-Y.,Chonnam National University
World Conference on Timber Engineering 2012, WCTE 2012 | Year: 2012
Stiffness of timber floor has been considered as one of major factors that influence the insulation performance against impact sound. Researches on evaluating the effect of floor constitutions have been carried out through the field measurements for timber framed buildings in Korea. It is concluded that the impact sound pressure level at the relatively lower frequency of 63Hz governs the overall insulation performance and can be improved by the reinforcement of floor stiffness, in case of heavy impact sound. From the result of this study, the effect of stiffness reinforcement on the insulation performance against heavy impact sound is shown very significant when the span of joist is shortened by the addition of beam at the mid-position of original span.
Jeong G.Y.,Chonnam National University |
Park J.S.,Korea forest Research Institute |
Hwang K.H.,Korea Forestry Promotion Institute
Wood and Fiber Science | Year: 2012
The goal of this study was to evaluate the load-carrying capacity of dovetail connections. Different tenon angles (y), tenon neck widths (w1), tenon head widths (w2), and tenon heights (h) were used to analyze stress distribution and strength from dovetail connections using the finite element method (FEM). Although different stress distributions were found from the FEM models, shear and tension perpendicular to the grain stresses were found to be the most critical stresses controlling strength of the dovetail connection. Strength of the dovetail connection predicted from the deterministic FEM models was validated from the results of experimental tests. A combination of four geometric parameters for mortise and tenon from the dovetail connection maximizing load-carrying capacity was found. Allowable load-carrying capacity of the dovetail connection was estimated using the stochastic finite element method associated with allowable stress design and load resistance factor design concepts. © 2012 by the Society of Wood Science and Technology.
Dilshara M.G.,Jeju National University |
Lee K.-T.,Korea forest Research Institute |
Jayasooriya R.G.P.T.,Jeju National University |
Kang C.-H.,Jeju National University |
And 8 more authors.
International Immunopharmacology | Year: 2014
Little is known about whether trans-isoferulic acid (TIA) regulates the production of lipopolysaccharide (LPS)-induced proinflammatory mediators. Therefore, we examined the effect of TIA isolated from Clematis mandshurica on LPS-induced nitric oxide (NO) and prostaglandin E2 (PGE2) production in BV2 microglial cells. We found that TIA inhibited the production of LPS-induced NO and PGE2 without accompanying cytotoxicity in BV2 microglial cells. TIA also downregulated the expression levels of specific regulatory genes such as inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) by suppressing LPS-induced NF-κB activity via dephosphorylation of PI3K/Akt. In addition, we demonstrated that a specific NF-κB inhibitor PDTC and a selective PI3K/Akt inhibitor, LY294002 effectively attenuated the expression of LPS-stimulated iNOS and COX-2 mRNA, while LY294002 suppressed LPS-induced NF-κB activity, suggesting that TIA attenuates the expression of these proinflammatory genes by suppressing PI3K/Akt-mediated NF-κB activity. Our results showed that TIA suppressed NO and PGE2 production through the induction of nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent heme oxygenase-1 (HO-1). Taken together, our data indicate that TIA suppresses the production of proinflammatory mediators such as NO and PGE2, as well as their regulatory genes, in LPS-stimulated BV2 microglial cells, by inhibiting PI3K/Akt-dependent NF-κB activity and enhancing Nrf2-mediated HO-1 expression. © 2013 Elsevier B.V. All rights reserved.
PubMed | Korea Forestry Promotion Institute, Inje University, Jeju National University, Korea forest Research Institute and Dong - Eui University
Type: Journal Article | Journal: International immunopharmacology | Year: 2014
Little is known about whether trans-isoferulic acid (TIA) regulates the production of lipopolysaccharide (LPS)-induced proinflammatory mediators. Therefore, we examined the effect of TIA isolated from Clematis mandshurica on LPS-induced nitric oxide (NO) and prostaglandin E2 (PGE2) production in BV2 microglial cells. We found that TIA inhibited the production of LPS-induced NO and PGE2 without accompanying cytotoxicity in BV2 microglial cells. TIA also downregulated the expression levels of specific regulatory genes such as inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) by suppressing LPS-induced NF-B activity via dephosphorylation of PI3K/Akt. In addition, we demonstrated that a specific NF-B inhibitor PDTC and a selective PI3K/Akt inhibitor, LY294002 effectively attenuated the expression of LPS-stimulated iNOS and COX-2 mRNA, while LY294002 suppressed LPS-induced NF-B activity, suggesting that TIA attenuates the expression of these proinflammatory genes by suppressing PI3K/Akt-mediated NF-B activity. Our results showed that TIA suppressed NO and PGE2 production through the induction of nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent heme oxygenase-1 (HO-1). Taken together, our data indicate that TIA suppresses the production of proinflammatory mediators such as NO and PGE2, as well as their regulatory genes, in LPS-stimulated BV2 microglial cells, by inhibiting PI3K/Akt-dependent NF-B activity and enhancing Nrf2-mediated HO-1 expression.
Kim C.,Gyeongnam National University of Science and Technology |
Park J.-H.,Gyeongnam National University of Science and Technology |
Byun J.-K.,Korea Forestry Promotion Institute |
Ma H.-S.,Gyeongsang National University
Annals of Forest Research | Year: 2013
This study was conducted to evaluate the litter fall and nutrient status of green leaves and leaf litter at various compound ratios of fertilizer in 28-year-old sawtooth oak (Quercus acutissima Carruth.) stands. The compound ratios of the fertilizer were N3P4K1 (100 kg N ha-1, 133 kg P ha-1, and 33 kg K ha-1), N6P4K1, N2P2K1, N3P8K1, N3P4K2, and N0P0K0 (control). Varying ratios of NPK were applied for three years (2002 - 2004), and the litter fall and green leaves were collected for one year (May 2005 - May 2006) and at the end of growing season (September 2005). Leaf litter was significantly higher (P < 0.05) in the N3P4K2 (3,423 kg ha-1 year-1) than in the N3P8K1 (2,741 kg ha-1 year-1) and N2P2K1 (2,891 kg ha-1 year-1) treatments. The N concentrations of the green leaves were significantly higher in the compound ratios of fertilizer (N3P4K1, N6P4K1, N3P8K1) than in the N0P0K0 treatment, but the N concentrations of the leaf litter were not affected by the fertilizer. The P and K concentrations in the green leaves were significantly higher in the highest dose (N3P8K1 and N3P4K2) of these nutrients than in the N0P0K0 treatment. The nutrient inputs by the leaf litter corresponded to the differences in the leaf litter mass or nutrient concentrations rather than the various compound ratios of fertilizer. Nutrient use and resorption efficiencies were only weakly controlled by various compound ratios of fertilizer. The results indicate that the nutrient status of green leaves may serve as an indicator of various compound ratios of fertilizer, whereas litter fall, nutrient use and resorption efficiency can be attributed to inherent soil conditions or stand characteristics following fertilizer application in sawtooth oak stands.
Kim Y.S.,Korea forest Research Institute |
Byun J.K.,Korea Forestry Promotion Institute |
Kim C.,Gyeongnam National University of Science and Technology |
Park B.B.,Korea forest Research Institute |
And 2 more authors.
Landscape and Ecological Engineering | Year: 2014
This study was conducted to determine fertilizer compound ratios suitable for soil conditions and tree seedling growth in recently burned areas in Korean forests. Currently, the conventional fertilizer ratio applied to undisturbed forests in Korea is N:P:K 3:4:1. In this study, Japanese red pine (Pinus densiflora S. et Z.) seedlings planted in the burned area were fertilized over four growing seasons with the following NPK compound ratios: unfertilized (CON), 3:4:1, 6:4:1, 3:8:1, and 3:4:2. Fertilization generally increased current-year needle nutrient concentrations of the seedlings, and the chlorophyll a:b ratio in CON was significantly lower than in all fertilized plots. Fertilization significantly affected the growth of the pine seedlings, which had 71-87 % more height growth and 29-67 % increased root collar diameter (RCD) compared to CON. The increases in height and RCD were significantly higher with the 6:4:1 and 3:8:1 ratios than with the 3:4:1 ratio. The 3:4:2 and 3:4:1 fertilizer ratios had no effect on the RCD growth of seedlings. This suggests that the early growth of pine seedlings could be improved by providing high N and P supplies to areas affected by forest fires rather than the conventional fertilizer ratio of 3:4:1 in Korean forest soils. Therefore, application of the suitable fertilization ratio may be a very effective way to reduce reforestation cost as well as to shorten restoration period. © 2012 International Consortium of Landscape and Ecological Engineering and Springer Japan.
PubMed | Health Science University, Nagoya University, Korea Forestry Promotion Institute, Sungkyunkwan University and 4 more.
Type: | Journal: Journal of medicinal food | Year: 2016
Escalating evidence indicates that ginseng treatment protects against psychotoxic behaviors and memory impairment. Although the underlying mechanism of schizophrenia remains elusive, recent investigations proposed that downregulation of glutathione (GSH) can be involved in the pathogenesis of this disorder. Since little is known about the effects of ginseng in a schizophrenia-like animal model, we selected mountain-cultivated ginseng (MG) from a variety of ginseng extracts to investigate the effect of ginseng on the psychosis induced by phencyclidine (PCP) in mice. PCP (10mg/kg/day, s.c.) was administered for 14 consecutive days. Novel object recognition, forced swimming, and social interaction tests were performed during the withdrawal period of 7 days. In addition, behavioral sensitization to an acute challenge of PCP was evaluated. The parameters of the GSH-dependent system in the prefrontal cortex (PFC) were examined. MG (200mg/kg, i.p./day) or antipsychotic clozapine (10mg/kg, p.o./day) was administered for seven consecutive days after the final PCP treatment. PCP significantly produced abnormal behaviors, followed by increases in Nrf2 nuclear translocation, its DNA binding activity, and glutamate-cysteine ligase (GCL) mRNA expression in the PFC. PCP treatment significantly decreased GSH/glutathione disulfide (GSSG) ratio and glutathione peroxidase (GPx) activity. MG significantly attenuated abnormal behaviors and the decreases in GSH/GSSG ratio and GPx activity induced by PCP. MG attenuated the increases in Nrf2 activity and GCL expression caused by PCP. The protective potentials of MG were comparable to those of clozapine. MG ameliorates PCP-induced schizophrenia-like psychosis in mice through the positive modulation of the glutathione system.
Kim J.-Y.,Seoul National University |
Kim T.-S.,Seoul National University |
Eom I.-Y.,Seoul National University |
Eom I.-Y.,Korea Research Institute of Chemical Technology |
And 4 more authors.
Journal of Hazardous Materials | Year: 2012
In this study, chromated copper arsenate-treated wood (CCA-W) and alkaline copper quaternary compounds-treated wood (ACQ-W) were subjected to fast pyrolysis at 500°C for ca. 2. s to produce bio-oil and char. The physicochemical properties of the pyrolytic products as well as the distribution of heavy metals - arsenic, copper and chrome - during fast pyrolysis were investigated. The water content, viscosity, pH and higher heating value (HHV) of bio-oil from CCA-W were 24.8. wt%, 13.5. cSt, 2.1 and 16. MJ/kg, respectively, whereas those of bio-oil from ACQ-W were 27.9. wt%, 16. cSt, 3.0 and 14.1. MJ/kg, respectively. The yields of bio-oil from CCA-W and ACQ-W were 43.3% and 46.6%, respectively, significantly lower than that of control (61.6%). In the pyrolytic products of CCA-W, the concentrations of arsenic, copper and chromium were determined to be 36.4. wt%, 74.0. wt% and 75.4. wt% in char, respectively, 34.5. wt%, 10.3. wt% and 9.0. wt% in bio-oil, respectively, and 29.0. wt%, 15.7. wt% and 15.5. wt% in gas, respectively. In addition, most of the copper appeared in the char (98.8. wt%) and only a trace amount of copper was detected in the bio-oil (0.2. wt%) produced by ACQ-W. © 2012 Elsevier B.V.
Kwon T.-S.,National Institute of Forest Science |
Kim Y.S.,National Institute of Forest Science |
Lee S.W.,Korea Forestry Promotion Institute |
Park Y.-S.,Kyung Hee University
Journal of Asia-Pacific Entomology | Year: 2016
We characterized changes in soil arthropod communities in response to changes in environmental factors in temperate forests in South Korea. Soil arthropods were collected at both deciduous and coniferous forests at three industrialized areas and one reference area for ten years. Our results showed that soils in the industrialized areas displayed significantly lower pH compared to the reference area. However, the abundance of arthropod was not different between the study areas. Abundance in deciduous forests was higher compared to coniferous forests, and community composition in deciduous forests varied during the study period. Precipitation was a key factor influencing changes in arthropod abundance, particularly above 100 mm/month. Annual abundance decreased gradually at most study sites over the study period, although the statistical significance was relatively low. It might be influenced by the long-term decline of soil nutrients related to growing environmental disturbances such as air pollution, acid rain, and increasing heavy rainfall due to climate change. Therefore, systematic and national long-term monitoring of the soil community is required to assess and mitigate natural as well as anthropogenic environmental pressures on soil ecosystems. © 2016 Korean Society of Applied Entomology, Taiwan Entomological Society and Malaysian Plant Protection Society.
Ji D.H.,Hokkaido University |
Ji D.H.,Korea Forestry Promotion Institute |
Mao Q.,Southwest University |
Watanabe Y.,Hokkaido University |
And 2 more authors.
Journal of Agricultural Meteorology | Year: 2015
We determined the effects of nitrogen (N) loading (35 kg N ha–1 y–1) on the needle morphological and photosynthetic traits of 4-year-old seedlings of Japanese larch (Larix kaempferi) under different three light intensities (open, 50% and 20% light) to evaluate how they adjust to low light conditions. Nitrogen deposition in forests has been increasing in East Asia. Although Japanese larch is not native to Hokkaido, northern Japan, this light demanding tree species is now a promising forestation species and reaches to the age of bearing cones for regeneration. Forest gaps affects the success in regeneration. This light-demanding tree is a promising reforestation species, but its success at natural regeneration depends on the availability of light. The net photosynthetic rate at light saturation (Psat) decreased with increasing shading. Nitrogen addition increased Psat in unshaded seedlings but not in 50% and 20% light seedlings. Independent of added N, photosynthetic adjustment to the light environment was regulated by the allocation of N between rubisco and light-harvesting proteins. Psatin full sun was higher with N than without; the difference would be related to changes of stomatal limitation (Ls). With added N, larch seedlings in shade may store extra N in rubisco. Therefore, though Japanese larch is light demanding conifer, at the N level used in this study, shaded Japanese larch seedlings can regenerate in forest floor. © 2015, Society of Agricultural Meteorology of Japan. All rights reserved.