• Journal of Korean Society of Forest Science
• /
• v.103 no.1
• /
• pp.129-136
• /
• 2014

This study aims to investigate the effect of frequency of using forest environment on workers' stress. Workers in medical and counseling industry, which is recently known to require heavy emotional burden and thus cause a lot of stress and burnout syndrome, participated in the study. We classified 370 subjects, who were working at medical and counseling service institutions in Seoul metropolitan area, into two groups according to frequency of using forest environment by conducting a screening survey. 69 subjects submitted written consent and were recruited for either forest therapy program or control-group test; the "high" group (n=27) at the high frequency of using forest environment and the "low" group (n=42) at the low level. We measured the level of stress by using psychosocial indicators such as Worker's Stress Response Inventory (WSRI), Recovery Experience Questionnaire (REQ), and Maslach Burnout Inventory-General Survey (MBI-GS) and biological ones such as heart rate variability (HRV), cortisol, and Natural Killer cell (NK cell). The results suggested that the level of stress differed by frequency. The "high" group showed significantly low scores in the depression and work sub-scale and the total score of WSRI, emotional exhaustion, professional efficacy and total score of MBI-GS, and high scores in the total score of REQ. Similar tendencies were observed in the most of other indicators of psychosocial measures. Regarding the biological indicators, the "high" group showed the highest SDNN, RMSSD and TP measures of HRV and NK Cell activity and the low cortisol, although the statistical power did not reach the significant level. Our results suggest that the subjects who use forest environment frequently show favorable stress level both psychologically and biologically.

• Journal of Korea Water Resources Association
• /
• v.57 no.6
• /
• pp.421-435
• /
• 2024

In April 2023, a wildfire broke out in Gangneung located in the east coast region due to the influence of the Yanggang-local wind. In this study, GIS-based RUSLE(Revised Universal Soil Loss Equation) and SEMMA (Soil Erosion Model for Mountain Areas) were used to evaluate the erosion rate due to vegetation recovery in a small watershed of the Gangneung WUI(Wildland-Urban Interface) fire. The small watershed of WUI fire has a low altitude range of 10-30 m and the average slope of 10.0±7.4° which corresponds to a gentle slope. The soil texture was loamy sand with a high organic content and the deep soil depth. As herbaceous layer regenerated profusely in the gully after the wildfire, the NDVI (Normalized Difference Vegetation Index) reached a maximum of 0.55. Simulation results of erosion rates showed that RUSLE ranged from 0.07-94.9 t/ha/storm and SEMMA ranged from 0.24-83.6 t/ha/storm. RUSLE overestimated the average erosion rate by 1.19-1.48 times compared to SEMMA. The erosion rates were estimated to be high in the middle slope where burned pine trees were widely distributed and the slope was steep and to be relatively low in the hollow below the gully where herbaceous layer recovers rapidly. SEMMA showed a rapid increase in erosion sensitivity under at certain vegetation covers with NDVI below 0.25 (Ic = 0.35) on post-fire hillslopes. Gentle slopes with high organic content and rapid recovery of natural vegetation had relatively low erosion rate compared to steep slopes. As subsequent infrastructure and human damages due to sediment disaster by heavy rain is anticipated in WUI fire areas, the research results may be used as basic data for targeted management and decision making on the implementation of emergency treatment after the wildfire.

• Journal of Wetlands Research
• /
• v.18 no.1
• /
• pp.32-38
• /
• 2016

The purpose of this study is to investigate the effects of the natural river conservation work and to find remedies for them, targeting Jangsu-cheon with high frequency of use by citizens among the rivers in Incheon Metroplitan City, Korea; for this, this study conducted investigations and analyses of Jangsu-cheon completed in December, 2008. As a result of investigating 3 spots for the water system of Jangsu-cheon over a total of 3 years (2009, 2010, 2014), it was found that benthic macro-invertebrates of a total of 3 phyla, 5 classes, 11 orders, 26 families, 56 species, and 980 specimens were distributed there. When they were analyzed by year, 18 families and 30 species in 2009, right after the natural river conservation work, and 22 families and 37 species in 2010, 2 years after the work, were found, with 7 species increasing in number; after that, as a result of the investigation in 2014, 22 families and 38 species were found, which tells the river has entered the stabilization stage since the recovery in 2010.Therefore, this study could identify: the water environment of the river was improved due to the natural river conservation work for Jangsu-cheon; in addition, Jangsu-cheon showed good ecological environment due to the continuous maintenance of the good wetlands in Incheon Grand Park in the upper area of the river; and the natural river conservation work of Jangsu-cheon created positive effects.

• Proceedings of the Ginseng society Conference
• /
• 1984.09a
• /
• pp.27-36
• /
• 1984

It was previously reported that red ginseng extract inhibited carcinogenesis by urethan, DMBA and aflatoxin $B_1E (Cancer Detection and Prevention, 6: 515-525, 1983). In an attempt to investigate the mechanism of the anticarcinogenic effect of ginseng, we assayed natural killer (N.K) activity in mice treated with urethan and benzo(a)pyrene. In our experiment newly born Swiss Webster mice, less than 24 hrs. old, were given a single subcutaneous injection of lmg of ure-than and 40ug of benzo(a)pyrene. The mice had been administered with ginseng since weaning, and sacrificed at various intervals. Major organs were examined both, with the naked eye and microscopically. N.K. activity of spleen cells was analyzed in a 12-hour $^{51}Cr^-release$ assay against YAC-1 cells. Administration of ginseng resulted in an increase of N.K. activity by $18\%$ at 4 weeks, $20\%$ (P < 0.05) at 6, $29\%$ (P < 0.05) at 12, and $13\%$ at 24 following a single injection of urethan. At the same time, significantly lower incidences of lung adenoma were noted at 6 weeks $(50\%)$ and 12 weeks $(27\%)$ following the administration of ginseng to urethan-injected mice. This result indicates that the enhancement of N.K. activity by ginseng makes a contribution to its anticarcinogenic effect. On the hand, N.K. activity was suppressed by benzo(a)pyrene during the time span of this experiment and it almost returned to the level of controls following the adminsitration of ginseng. However, the lung adenoma induced by benzo(a)pyrene began to occur at 48 weeks in which N.K. activity had naturally declined to a very low level in all experimental mice, and administration of ginseng did not decrease the incidence. In explanation of this result, we might propose that the recovery of the N.K. activity by ginseng had little effect on the incidence of lung adenoma because of the long latent period of carcinogenesis by benzo(a)pyrene. In conclusion, these results suggest that the anticarcinogenic effect of ginseng in urethan-treated mice may be related to the augmentation of N.K. activity.

• Journal of Korean Society of Forest Science
• /
• v.100 no.1
• /
• pp.112-117
• /
• 2011

This study was conducted for searching the functional feeding groups, and community stability of the macroinvertebrate on forest fire area of Uljin-gun. The samples were collected from 2 sites of control area and 2 sites of experimental area during 2007 to 2009. The identified species were 89 belonged to 47 families, 16 order, 6 class, and 4 phylum in control area. And 84 belonged to 43 families, 16 order, 6 class, and 4 phylum were identified in experimental area. As a result of changes in species and individuals of E.P.T. taxa investigated in experimental area by year, Ephemeroptera was 21 species, $2,434.6inds./m^2$, Plecoptera was 3 species, $199.8inds./m^2$, and Trichoptera 14 species, $540.2inds./m^2$ in 2007. And in 2009, Ephemeroptera was 9 species, $296inds./m^2$, Trichoptera was 4 species, $44.4inds./m^2$, and Plecoptera was none, showing that species and individuals belonging to E.P.T. taxa decrease rapidly every year. Community analysis by year, in 2008 when the water system started to be influenced by the fire directly, it showed a trend that H' and RI decreased in the experimental area. Functional feeding group by year, it showed a trend that species and individuals of GC type which is a functional group picking up and eating FPOM (fine particulate organic matter) from deposits in the bottom of water or benthic areas and performs an important function of material circulation in ecosystem decrease every year. Community stability by year, an environment of water system in forest fire area started to be somewhat destroyed, from 2008, it is shown that both species in I area which have great ability of resistance and recovery and species in III area which live in relatively stable water system decreased a little.

• Korean Chemical Engineering Research
• /
• v.59 no.3
• /
• pp.345-358
• /
• 2021

This study focuses on the development of the liquid air production process that uses LNG (liquefied natural gas) cold energy which usually wasted during the regasification stage. The liquid air can be transported to the LNG exporter, and it can be utilized as the cold source to replace certain amount of refrigerant for the natural gas liquefaction. Therefore, the condition of the liquid air has to satisfy the available pressure of LNG storage tank. To satisfy pressure constraint of the membrane type LNG tank, proposed process is designed to produce liquid air at 1.3bar. In proposed process, the air is precooled by heat exchange with LNG and subcooled by nitrogen refrigeration cycle. When the amount of transported liquid air is as large as the capacity of the LNG carrier, it could be economical in terms of the transportation cost. In addition, larger liquid air can give more cold energy that can be used in natural gas liquefaction plant. To analyze the effect of the liquid air production amount, under the same LNG supply condition, the proposed process is simulated under 3 different air flow rate: 0.50 kg/s, 0.75 kg/s, 1.00 kg/s, correspond to Case1, Case2, and Case3, respectively. Each case was analyzed thermodynamically and economically. It shows a tendency that the more liquid air production, the more energy demanded per same mass of product as Case3 is 0.18kWh higher than Base case. In consequence the production cost per 1 kg liquid air in Case3 was $0.0172 higher. However, as liquid air production increases, the transportation cost per 1 kg liquid air has reduced by $0.0395. In terms of overall cost, Case 3 confirmed that liquid air can be produced and transported with $0.0223 less per kilogram than Base case.

• Journal of Ginseng Research
• /
• v.32 no.4
• /
• pp.382-389
• /
• 2008

To achieve a better understanding of protective effects of water extracts of Panax ginseng against TCDD-induced toxicities, we monitored physiological and clinical changes in rat for 4 weeks after administrations of each Panax Ginseng extract or TCDD, and co-administration of the two materials. For this study, 120 male Sprague-Dawley (SD) rats weighing 190-210 g each (8 weeks old) were divided into four groups: TCDD-administered, co-administered group with TCDD and ginseng extract, ginseng extract-administered, and control group. The TCDD-administered group received single dose of TCDD in a corn oil vehicle ($25\;{\mu}g/kg$ body weight) by intraperitoneal administration on Day 1. The Panax ginseng extracts-administered group received intraperitoneally 100 mg/kg body weight every other day for one month. For the co-administered group with TCDD and ginseng extracts, Panax ginseng extracts were intraperitoneally administered to rats at 100 mg/kg body weight every other day for one month after a single intraperitoneal dose of $25\;{\mu}g$ of TCDD/kg body weight on Day 1. Panax ginseng extracts attenuated the mortality induced by TCDD administration. The extracts also slightly attenuated the TCDD-induced body weight loss. Administration of TCDD alone increased liver weight at 2, 5, and 16 days after administration of TCDD. Administration of Panax ginseng extracts rather decreased liver weight through whole the experimental period, but which was statistically insignificant. Administration of TCDD alone at $25\;{\mu}g/kg$ body weight increased both serum enzyme activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) at 32 days, indicating that liver damage occurred maximally at that time. Ginseng extract administration caused insignificant changes in serum ALT, but gradually decreased in AST as the exposure time increased. Coadministration of TCDD and ginseng extracts caused serum AST activity to significant recovery to normal value at 16 days and 32 days after exposure to TCDD. The extracts also significantly decreased the TCDD-induced ALT activity after 16 days of TCDD administration. These results suggest that Panax ginseng extracts may possess a protective effect against TCDD-induced toxicities including hepatotoxicity in rats.

• Journal of Bio-Environment Control
• /
• v.27 no.1
• /
• pp.94-101
• /
• 2018

Mugwort (Artemisia princeps) is a medicinal plant that has a substance called euphatilin, which is effective for cell damage and gastritis recovery. The objectives of this study were to investigate the annual growth characteristics of Artemisia princeps in greenhouse and to increase the eupatiline content by environmental stresses. Growth and eupatilin content of the plants were compared after 6 weeks of seedling and subsequent 8 weeks of greenhouse cultivation. Photosynthesis of mugwort plants did not saturate even at a relatively high light intensity of $1,200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Growth rate of the plants reached its highest at two weeks after transplanting and began to decrease since 8 weeks after transplanting. The plants showed typical characteristics of a perennial herbaceous plant as they were sensitive to seasonal changes. In particular, the plants showed high growth and eupatilin content in spring and summer as vegetative growth periods, but flowering and wintering caused considerable decreases in growth and eupatilin content in fall and winter. Therefore, application of night interruption is essential for year-round cultivationof the plant. Two stresses and a elicitor were treated: drought stresses by stopping irrigation at 5, 6, 7, and 8 days before harvest; salt stresses with nutrient solution concentrations of 2, 4, 6, 8, and $10dS{\cdot}m^{-1}$ by adding sodium chloride at 3 days before harvest; and foliar applications of methyl jasmonates of 12.5, 25, 50, and $100{\mu}M$ at 3 days before harvest. Significant increase in eupatilin content was observed at drought stresses of 7- and 8-days of irrigation stop and foliar application of $25{\mu}M$ methyl jasmonate, while no significant increase observed at salt stresses. From the results, it was confirmed that the environmental treatments can improve the productivity and quality of Artemisia princeps as a phamaceutical raw material.

• Journal of the Speleological Society of Korea
• /
• no.63
• /
• pp.1-8
• /
• 2004

The non-magnetic materials with non-conductive showing high structure dispersity were developed on the base of natural quartz and lava-scoria which was collected from Je-ju island in Korea, and treated by methane-chemical technology those were obtained novel properties of magnetization through the analyzing. Depending on the processing conditions and subsequent applications the materials produced by strong methane-chemical reaction (MCR) in alcohol solution showed concurrently magnetic, dielectric and electrical properties. The obtained magnetic-electrical powders classified by aggregate complex of their features as segnetomagnetics, containing a dielectric material as a carrying nucleus, particularly the quartz on that surface one or more layers of different compounds were synthesized having thickness up to 10～50 nm and showing magnetic, electrical and other properties. It was confirmed in magnetizing process that powders of quartz and lava-scoria produced by MCR were better oil adsorbent as of oleophilic and floating matter on water surface although their specific gravities are comparably more than 1 in quartz or less than unity, as that of water, in lava-scoira. Therefore, it will be Possible and very useful to remove low density and light gravity oil spillage in difficult recovery from sea and inland water contamination spread on water surface, by marine accident and ship sinking accident occurring frequently in recent years, by way of magnetic adsorbent conveyer system in continuous, if it could be built up the mass Production system of water-floating magnetizable oleophilic adsorbent materials with use of iow cost and good Qualify lava-scoria spread on volcano district in Je-ju island. And, there will also be urgent advent of necessity with strong possibility to develop useful applications of various magnetic functional materials include oleophilic adsorbent for removal of sea oil-contaminants and maritime pollutants, and other kinds of various utilities in industrial applications and practical uses of novel functional materials in the fields of environments and health care applications with in deep expectation.

• The Korean Journal of Mycology
• /
• v.34 no.1
• /
• pp.7-14
• /
• 2006

Entomopathogenic fungus Cordyceps militaris is famous for its medicinal efficacies. It has been reported to have various pharmacological activities such as anti-tumour, insecticidal, antibacterial, immunomodulatory and antioxidant. In this study, we investigated the effect of the extract of C. militaris (MPUN8501), which was identified by the analysis of the nucleotide sequences of 5.8S ribosomal RNA, on the function of liver. C. militaris powder was extracted using hot water extracts method as time, volume and temperature and using method as differential polarity of organic solvent. Each fraction was tested for the improvement of hepatic enzyme alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) activity. The BuOH extracts (CME) had highest activity which was used for the test of toxicity and efficacy of C. militaris. The enhancing effect of CME on the activity of ADH and ALDH was much more than medicine, drink, natural tea etc. Thus CME promoted the resolution of alcohol and acetaldehyde in rats, inducing recovery to normal condition rapidly. Furthermore, oral administration of CME effectively protected the carbon tetrachloride-induced acute hepatic injury as revealed by the hematological parameters (levels of sGOT and sGPT) and histological observation. CME was ascertained to be safe by regulatory toxicity studies of single dose toxicity and genotoxicity. These results suggest that CME would be useful for the maintaining normal hepatic activity as a functional health food.