• Journal of the Korean Society of Environmental Restoration Technology
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• v.22 no.5
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• pp.27-43
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• 2019

This study applied the LANDIS-II model to the forest vegetation of the study area in Yeongdong-gun, Korea to identify climate effects on ecosystems of forest vegetation. The main purpose of the study is to examine the long-term changes in forest aboveground biomass(AGB) under three different climate change scenarios; The baseline climate scenario is to maintain the current climate condition; the RCP 4.5 scenario is a stabilization scenario to employ of technologies and strategies for reducing greenhouse gas emissions; the RCP 8.5 scenario is increasing greenhouse gas emissions over time representative with 936ppm of $CO_2$ concentration by 2100. The vegetation survey and tree-ring analysis were conducted to work out the initial vegetation maps and data for operation of the LANDIS model. Six types of forest vegetation communities were found including Quercus mongolica - Pinus densiflora community, Quercus mongolica community, Pinus densiflora community, Quercus variabilis-Quercus acutissima community, Larix leptolepis afforestation and Pinus koraiensis afforestation. As for changes in total AGB under three climate change scenarios, it was found that RCP 4.5 scenario featured the highest rate of increase in AGB whereas RCP 8.5 scenario yielded the lowest rate of increase. These results suggest that moderately elevated temperatures and $CO_2$ concentrations helped the biomass flourish as photosynthesis and water use efficiency increased, but huge increase in temperature ($above+4.0^{\circ}C$) has resulted in the increased respiration with increasing temperature. Consequently, Species productivity(Biomass) of trees decrease as the temperature is elevated drastically. It has been confirmed that the dominant species in all scenarios was Quercus mongolica. Like the trends shown in the changes of total AGB, it revealed the biggest increase in the AGB of Quercus mongolica under the RCP 4.5 scenario. AGB of Quercus mongolica and Quercus variabilis decreased in the RCP 4.5 and RCP 8.5 scenarios after 2050 but have much higher growth rates of the AGB starting from 2050 under the baseline scenario. Under all scenarios, the AGB of coniferous species was eventually perished in 2100. In particular they were extinguished in early stages of the RCP 4.5 and RCP 8.5 scenarios. This is because of natural selection of communities by successions and the failure to adapt to climate change. The results of the study could be expected to be effectively utilized to predict changes of the forest ecosystems due to climate change and to be used as basic data for establishing strategies for adaptation climate changes and the management plans for forest vegetation restoration in ecological restoration fields.

• The Korean Journal of Ecology
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• v.27 no.1
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• pp.15-20
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• 2004

With attention to different human activities around Anzali wetland and introduction of different pollutants containing heavy metals into this water ecosystem and absorption and accumulation of heavy metals in shell and muscle of Astacus leptodactylus which is native benthose of Anzali wetland and enjoys food and economic importance; Sampling of waters and sediments from 18 stations and shell and muscle of Astacus leptodactylus from 5 stations had been conducted. After biometric evaluation of Astacus leptodactylus, the chemical analysis of the samples by using international and standard methods and then their heavy metals content was determined by Atomic Absorpotion Spectrophotometer (AAS), model P.U 9400 philips. Result of the analysis stated that; 1) The mean values of Cr, Zn, Pb, Ni, V in Anzali waters were 6.4, 184.5, 28.8, 28.9, 47.1 ($\mu$ gr/lit) respectively, which comparing to the international standards, is not suitable for drinking, but it can be used for agricultural and aquacultural purposes. Even though the concentration of heavy metals in sediments were high, there are in range of acceptable limit for aquatics organisms; 2) Comparatively, the concentration of heavy metals in shell and muscle of Astacus leptodactylus in Anzali wetland (Cr, Zn, Pb, Ni, V in shell were 3.48, 109.3, 14.13, 7.17, 36.2 and in muscle were 2.98, 131.98, 3.12, 4.77, 9.05 ppm respectively) were more than what is determined for Aras dam (in shell were 1.6, 224.3, 7.8, 7.6, 10.3 and in muscle were 1.4, 60.2, 0.45, 2.7, 4.4 mg/kgr respectively); 3) For all samples, concentration of heavy metals in all Astacus leptodactylus in Anzali wetland and Aras dam, was at tolerance level for human consumption; 4) There was no association with significant difference between weight and size of Astacus leptodactylus with absorption and accumulation of heavy metals; but there was a significant association between heavy metals content in water and in sediments, and in sediments, shell and muscle of Astacus leptodactylus in Anzali wetland.

• Journal of Environmental Health Sciences
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• v.46 no.1
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• pp.78-87
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• 2020

Objectives: To identify the degree of physical burden, a determination was undertaken of dust collection efficiency, inhalation pressure, and CO₂ concentration related to health masks certified by the Ministry of Food and Drug Safety (MFDS). Methods: Twenty health masks were purchased on the market. Dust collection efficiency and inhalation pressure were determined in the same manner as in MFDS certification testing, respectively using TSI Model 8130 (TSI, U.S.) and ART Plus (Korea). CO₂ concentrations for 20 subjects using a CO₂ analyzer (G100, G150, Geotechnical Instrument Ltd., UK) were measured with a similar method as a total inward leakage test. In addition to CO₂ levels, dead space volumes in the masks was determined for predicting concentrations of CO₂ in inhalation air. Results: Most of the dust collection efficiencies found for the 20 masks were far higher than the standard. Four KF94s met KF99 and four KF80s even met KF94. Most inhalation pressures were also much lower than the standard, with many almost one-half of the standard. The mean and standard deviation of CO₂ concentration in the mask were 2.9±0.44%. Considering dead volume, the prediction for CO₂ concentration in the inhalation air was 4,395±1,266 ppm. Conclusions: For healthy men and women, the dust collection efficiency and inhalation pressure of health masks were not at a level that would affect their health. Although CO₂ levels in the inhalation air were predicted not to affect health, research on the physiological effects of health masks on Koreans is needed for more precise research.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.3
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• pp.273-281
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• 2012

The government is carrying forward a sustainable development which reduces green-house gas and environmental pollution by preparing 'Low Carbon Green Development' policy basis as a new paradigm of national development. This study aims to understand the status of atmosphere contamination which Seoul has by finding correlation among social, economical indexes and carbon, the humanities and social characteristic materials which best express types of city and correlation and to suggest implications. According to the results of the analysis, first the carbon emission volume of Seoul recorded 0.56 ppm, Jongno, Jung-Gu, Kuro, Kangnam and Songpa were more than the average of Seoul and Kwangjin-Gu & Kangbuk-Gu, relative north east regions, Yeongdeungpo-Gu and Dongjak-Gu, south west regions showed lower CO occurrences. Second, according to the correlation and factor analysis, elements which affect CO emission volume of Seoul are largely represented by regional level, traffic level and development density level. Third, when the importance of influence factors based on the analyzed standard coefficient by a regression model, traffic and development density level were most important by recording traffic level (0.967), environmental level (0.385), regional level (0.530) and development density (0.561). Consequently, it was revealed that the traffic level most affected CO emission.

• Asian Journal of Atmospheric Environment
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• v.10 no.3
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• pp.125-136
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• 2016

In this study, the effects of the mesh barrier on the free dispersion of ammonia were numerically investigated under different atmospheric conditions. This study presents the detail and flow feature of the dispersion of ammonia through the mesh barrier on various free stream conditions to decline and limit the toxic danger of the ammonia. It is assumed that the dispersion of the ammonia occurred through the leakage in the pipeline. Parametric studies were conducted on the performance of the mesh barrier by using the Reynolds-averaged Navier-Stokes equations with realizable k-${\varepsilon}$ turbulence model. Numerical simulations of ammonia dispersion in the presence of mesh barrier revealed significant results in a fully turbulent free stream condition. The results clearly show that the flow behavior was found to be a direct result of mesh size and ammonia dispersion is highly influenced by these changes in flow patterns in downstream. In fact, the flow regime becomes laminar as flow passes through mesh barrier. According to the results, the mesh barrier decreased the maximum concentration of the ammonia gas and limited the risk zone (more than 500 ppm) lower than 2 m height. Furthermore, a significant reduction occurs in the slope of the upper boundary of $NH_3$ risk zone distribution at downstream when a mesh barrier is presented. Thus, this device highly restricts the leak distribution of ammonia in the industrial plan.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.1
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• pp.70-76
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• 2013

Some fish live in aquatic environments with low or temporally changing $O_2$ availability. Variation in dissolved oxygen (DO) levels requires behavioral, physiological, and biochemical adaptations to ensure the uptake of sufficient $O_2$. Several species are relatively well adapted to tolerate low $O_2$ partial pressures (hypoxia). The medaka (Oryzias dancena ) is an important model organism for biomedical research that shows remarkable tolerance to hypoxia. We investigated the regulation and role of hypoxia-inducible factor-1 (HIF-$1{\alpha}$) as a general hypoxia-response gene and stanniocalcin-2 (STC2), which is one of the genes regulated by HIF-$1{\alpha}$ in mammals under hypoxia. We subjected adult male medaka to the following three acute hypoxia regimes: 1, 24, and 72 h at DO = $1.8{\pm}0.5$ ppm. The changes in STC2 and HIF-$1{\alpha}$ mRNA were monitored using quantitative real-time reverse-transcription PCR. We found strong upregulation of HIF-$1{\alpha}$ mRNA in the livers of fish exposed to hypoxia. Hypoxia rapidly upregulated STC-2 mRNA expression in muscle, but not in the brain, gills, liver, or intestine. Therefore, unlike in mammals, hypoxia might regulate O. dancena STC-2 expression in an HIF-$1{\alpha}$-independent manner.

• Journal of Nutrition and Health
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• v.39 no.8
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• pp.733-741
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• 2006

The study was conducted to investigate the effects of dietary calcium and soy isoflavone on body fat and lipid metabolism in high fat-induced obesity. Four week old female C57/BL6J mice, known as a good model of diet-induced obesity, were fed low Ca and high fat diet for 6 weeks. After induced obesity, mice were divided into six groups according to diets varying calcium contents (0.1 or 1.5%) and genistein contents (0 or 500 or 1,000 ppm). Body weight, fat pad (perirenal fat and parameterial fat), adipocyte size, serum total lipid and total cholesterol were significantly decreased by both high Ca intake and genistein supplementation. However, the effect of genistein supplementation showed in low Ca-fed groups. Serum LDL-cholesterol and TG were significantly decreased by high Ca intake and genistein supplementation, respectively. In liver, lipogenic enzymes (fatty acid synthase and malic enzyme) activity and TG were significantly decreased by both high Ca intake and genistein supplementation. This inhibitory effect of genistein on lipogenic enzymes showed in low Ca-fed groups. But liver total cholesterol and total lipid were significantly decreased by high Ca intake and genistein supplementation, respectively. Fecal excretion of total lipid, total cholesterol and TG were significantly increased by high Ca intake, not by genistein supplementation. In conclusion, high calcium intake and genistein supplement may be beneficial for suppression of obesity through direct anti-adipogenesis by decreasing fat weight and size and indirect anti-lipo-genesis by inhibiting lipogenic enzymes activity and improving lipid profile.

• Nuclear Engineering and Technology
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• v.35 no.6
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• pp.529-536
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• 2003

The objective of this study is to investigate the reorientation of hydrides with applied stress intensity factor, the peak temperature and the time when to apply the stress intensity factor in a Zr-2.5Nb pressure tube during its thermal cycle treatment. Cantilever beam (CB) specimens with a notch of 0.5 mm in depth made from the Zr-2.5Nb tube were subjected to electrolytic hydrogen charging to contain 60 ppm H and then to a thermal cycle involving heating to the peak temperature of either 310 or $380^{\circ}C$, holding there for 50 h and then cooling to the test temperature of $250^{\circ}C$. The stress intensity factor of either 6.13 or $18.4\;MPa\sqrt{m}$ was applied at the beginning of the thermal cycle, at the end of the hold at the peak temperatures and after cooling to the test temperature, respectively. The reorientation of hydrides in the Zr-2.5Nb tube was enhanced with the increased peak temperature and applied stress intensity factor. Furthermore, when the CB specimens were subjected to $18.4\;MPa\sqrt{m}$ from the beginning of the thermal cycle, the reoriented hydrides occurred almost all over the Zr-2.5Nb tube, surprisingly suppressing the growth of a DHC crack. In contrast, when the CB specimens were subjected to the stress intensity factor at the test temperature, little reorientation of hydrides was observed except the notch region, leading the Zr-2.5Nb to grow a large DHC crack. Based on the correlation between the reorientation of hydrides and the DHC crack growth, a governing factor for DHC is discussed along with the feasibility of the Kim's DHC model.

• Culinary science and hospitality research
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• v.23 no.8
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• pp.153-162
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• 2017

Bacillus coagulans was added as probiotics in instant coffee with microground roasted coffee which is recently rising premium coffee and the instant coffee (ProBio coffee) was compared with 3 commercial instant coffees with microground roasted coffee in quality characteristics to understand the competitiveness of ProBio coffee. In sensory evaluation, ProBio coffee had inferior aroma intensity and overall acceptance compared with control group (brewed coffee) (p<0.05) but it had equal quality or more compared with 3 commercials. Total polyphenol content, chlorogenic acid content, DPPH free radical scavenging activity and caffeine content were $110.72{\pm}1.99mg/g$, $2,700{\pm}20mg/g$, $146.22{\pm}3.62TEAC\;mg/g$, $28.1{\pm}3.2ppm$ respectively. In general quality characteristics, water content, solubility, particle size and particle strength of ProBio coffee were similar to general instant coffee but had darker color than it. In safety assessment, acrylamide content was $502{\pm}10ppb$, and residual pesticides and ochratoxin A were not detected. Over 70% of B. coagulans were maintained in 4 months of storage and 16 months of shelf life was predicted in ProBio coffee by $Q_{10}$ model. Therefore, ProBio coffee was confirmed to have a sufficient product competiveness compared with 3 commercials.

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.347-349
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• 2009

Air quality of indoor space environment is affected by various pollutants like as particles and chemical stuffs. The indoor air pollution affects directly the human respiration organs to cause consequently unpleasant mental status. The $CO_2$ concentration level is one of the harmful components of air pollutants. Major factor to increase the $CO_2$ concentration level is the people's breath amount in indoor. The car exhaust gas diffused from the around road also has strong affect on $CO_2$ concentration. There are some other reasons to affect the $CO_2$ concentration change, such as, real-time change of the population movement, closeness to the indoor air flow inlet window and changes in road car traffic amount. A remote monitoring system to measure environmental indoor air pollution concerning on the $CO_2$ concentration was studied and installed realized set-up model. Zigbee network configuration was applied for this system and the $CO_2$ concentration data were collected through USN network. A software program was developed to assure systematic analysis and to display real-time data on web pages. For the experimental test various condition was set up, like as, window opening, stopping air condition operation and adjusting fan heater work, etc. The analysis result showed the relation of various environmental conditions to $CO_2$ concentration changes. The causes to increase $CO_2$ concentration were experimentally defined as windows closing, the stopping air condition system, fan heater operation. To keep the $CO_2$ concentration under the legally required ppm level in public access indoor space, the developed remote measurement system will be usefully applied.