• Journal of Soil and Groundwater Environment
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• v.10 no.1
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• pp.43-57
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• 2005

Twelve bottom sediments and three cores were collected in Juam reservoir for a study on transportation, which was controlled by particle grain size (2mm-200{\mu}m,\;200-100{\mu}m,\;100-50{\mu}m,\;50-20{\mu}m,\;<20{\mu}m), and vertical distribution of heavy metals. Sediment cores were sliced into 2 to 5 cm intervals to measure heavy metal concentrations in interstitial water and sediments with depth. Pb isotopic compositions of core samples were determined to calculate sedimentation rate. Regardless of sampling sites, levels of heavy metals and trace elements in bottom sediments are nearly constant with mean values of $14.9\;{\mu}g/g\;for\;As,\;0.81{\mu}g/g\;for\;Cd,\;30.7{\mu}g/g\;for\;Cu,\;34.7{\mu}g/g\;for\;Ni,\;63.3{\mu}g/g\;for\;Pb\;and\;87.9{\mu}g/g\;for\;Zn$. In general, Cu, Pb, Zn, Wi, and Cr in fraction of $<20{\mu}m$ exhibit the highest concentration, but content of As is the highest in grain size of $2\;mm-200\;{\mu}m$ and $200-100\;{\mu}m$. Fe and Mn occur as the dissolved compositions of the highest concentrations in interstitial waters and increase in their concentrations toward lower part of cores. On the contrary, concentrations of Zn and Cu show the highest value in the uppermost part in cores, suggesting these elements are released from reductive dissolution of hydroxides and oxidation of organic matters under different redox conditions. The highest accumulations of Cu, Ni, Pb, and Zn contents in the sediment cores are observed at 0-4 cm layers, and concentrations of Cu and Pb are especially high, implying these heavy metals are originated from anthropogenic sources. The apparent sedimentation rate estimated using unsupported $^{210}Pb$ is 0.91 cm $year^{-1}$, corresponding about 10 cm sedimentation in total depth since construction of Juam dam. These results will provide available information for management of bottom sediment in Juam reservoir.

• The Journal of Engineering Geology
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• v.28 no.3
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• pp.411-429
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• 2018

Daeyoung mine (also called "Daema mine") produced gold and silver from mainly gold- and silver-bearing quartz veins. The mine tailings are a waste hazard, but most of the tailings were swept away or dispersed throughout the area around the mine long before the tailing dump areas were transformed into agricultural land. Soil liner and protection facilities, such as retaining walls, were constructed in the mine area to prevent the loss of tailings. The content of the tailings is 3,424.41~3,803.61 mg/kg, which exceeds the safety standard by a factor of 45. In addition, contamination was detected near agricultural areas and in the sediments in downstream drainage channels. A high level of As contamination was concentrated near the waste tailings yard; comparaable levels were detected in agricultural areas close to streams that ran through the waste dump yard, whereas the levels were much lower in areas far from the streams. The contamination in stream sediments showed a gradual decrease with distance from the mine waste yard. Based on these contamination patterns, we concluded that there are two main paths that affect the spread of contaminants: (1) loss of mine waste, and (2) the introduction of mine waste into agricultural areas by floods after transportation by streams. The agricultural areas contaminated by mass inflow of mine waste can act as contamination sources themselves, affecting other agricultural areas through the diffusion of contaminants. At present, although the measured effect in minimal, sediments in streams are contaminated by exposed mine waste and surface liners. It is possible for contaminants to diffuse or spread into nearby areas if heavy elements trapped in soil grains in contaminated agricultural areas leach out as soil solution or contaminant particles during diffusion into the water supply.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.4
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• pp.527-536
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• 1996

The patterns of diel horizontal migration (DHM) of 7 copepod species are compared as part of a general investigation of the zooplankton adaptations to the surf zone habitats. In a sandy shore surf zone of Yongil Bay, 3 sites such as the bottom and surface of 1 m water depth and water's edge are sampled with a sledge net(n=108). The surf zone copepod assemblage is dominated by 7 species; Acartia hudsonica, Fseudodiaptomus marinus, Paracalanus indicus, Calanus sinicus, Oithona similis, Sinocalanus tenellus and Labidocera bipinnata. Threefold variations in copepod abundance are observed within a diel cycle. Abundances of 7 dominant species and total copepods captured in the surface exhibit significant diel differences, but those taken in the bottom are not significantly affected by diel period. It is shown that about $90\%$ of the surf zone copepods performed DHM. The nocturnal high densities of copepods occurred for a neap tide when the offshore winds prevailed, suggesting the animals' ability for horizontal orientation and an active locomotion without invoking passive transportation by currents. Photoreactive behavior of copepods triggered by relative changes in light intensity may be a primary factor inducing DHM by aggregating in the surf zone during the night and spreading out at day; then copepods may reduce encounters with visual predators. In A. hudsonica, ontogenetic variations in timings of DHM are evident. Such variations are likely to minimize intraspecific competition for diets. Data on shoreward migration of copepods indicate that A. hudsonica, P. indicus, O. similis and S. tenellus can maintain swimming velocities of about $20m\;h^{-1}$ for durations of more than an hour. Our observations of strong diel difference in abundances point out the need for both day and night samplings in surf zone habitats, if the importance of these habitats to planktonic copepods are to be fully understood.

• Journal of the Korean Institute of Landscape Architecture
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• v.20 no.3
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• pp.64-78
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• 1992

In this study, elementary school students of both urban and rural areas as its subjects were asked to draw 'A beautiful landscape' by employing the perspective representation technique, i. e., the Perception Map, and to write down the elements comprising 'A beautiful landscape' in the questionnaire sheets. By doing so, an attempt was made 1) to analyze whether there are differences in perceiving 'A beautiful landscape' according to the differences of the environment in which they were brought up ; and, if there are differences. 2) to identify them ; and based on that , 3) to present basic data for evaluation on landscape, on its preference analysis and for Park Planning. The summary of this study is as follows ; 1) The main elements, elementary school students think, comprising 'A beautiful landscape' are 25 ones such as Sky(7), Sea(2), Water(2), Topography(5), Plants(5), Animals(3), School(1), Rural village(1). The natural elements showing a difference are ; Water fall in urban areas and School landscape in rural areas ; the artificial elements are ; City groups(Structures, Facilities, Necessities, Transportation means and Space) in urban areas and School groups in rural areas. Especially, in case of rural area children, they regard 'Trees' as an essential element to be 'A beautiful landscape' comparing to those in urban areas. 2) According to the analysis result on the correlation between the elements comprising a beautiful rural landscape and a beautiful ruban landscape, the correlation between boys and girls is high, showing the same trend with any difference. In comparison of urban areas with rural areas, there is no difference between natural elements, but in artificial elements(7 groups without family) the correlation is quite low, showing that all comprising elements are not the same between rural schools and cities, between schools within the same areas, and between schools of different areas. 3) In identifying the names of elements comprising 'A beautiful landscape', Back-Du Mountain and Sorak Mountain are shown the highest frequency in the category of mountains. In the names of trees and flowers, the elementary school children are thought to consider the kinds of trees and flowers they can see always at hand, i. e., those in their school ground where they spend most of their day time. 4) In the analysis of the numbers of comprising elements according to the responses in the questionnaire sheets and in the Perception Map, 'less than 10' is the most frequently counted number of comprising elements by individual students regardless of rural and urban differences. When the total frequency is divided by the number of students, the mean score is 6-7 without any differences between rural and urban areas, implying that there are no differences in the expression ability between urban and rural schools. 5) According to the result of classyfying and analysizing the landscape appeared on the Perception Map by similar elements and by similar scenes, 'A beautiful landscape' thought by elementary school children is defined not as a standardized form but as 11 types such as the landscape of fields, the landscape of a sea, the landscape of a rural village, a type where elements are assembled, the landscape of cities, the landscape of a school, the landscape coming out of a imagination, and other landscape. Both rural and urban children all consider the landscape of mountains and field and the landscape where several elements are assembled as a commonly beautiful one. Among the landscapes showing rural and urban differences, it can be analyzed that urban children regard the landscapes of cities, imagination, and waterfalls as something characteristic, while rural children regard the landscape of schools and rural villages as something characteristic.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.7
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• pp.380-394
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• 2015

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2014. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of heat and mass transfer, cooling and heating, and air-conditioning, the flow inside building rooms, and smoke control on fire. Research issues dealing with duct and pipe were reduced, but flows inside building rooms, and smoke controls were newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for thermal contact resistance measurement of metal interface, a fan coil with an oval-type heat exchanger, fouling characteristics of plate heat exchangers, effect of rib pitch in a two wall divergent channel, semi-empirical analysis in vertical mesoscale tubes, an integrated drying machine, microscale surface wrinkles, brazed plate heat exchangers, numerical analysis in printed circuit heat exchanger. In the area of pool boiling and condensing, non-uniform air flow, PCM applied thermal storage wall system, a new wavy cylindrical shape capsule, and HFC32/HFC152a mixtures on enhanced tubes, were actively studied. In the area of industrial heat exchangers, researches on solar water storage tank, effective design on the inserting part of refrigerator door gasket, impact of different boundary conditions in generating g-function, various construction of SCW type ground heat exchanger and a heat pump for closed cooling water heat recovery were performed. (3) In the field of refrigeration, various studies were carried out in the categories of refrigeration cycle, alternative refrigeration and modelling and controls including energy recoveries from industrial boilers and vehicles, improvement of dehumidification systems, novel defrost systems, fault diagnosis and optimum controls for heat pump systems. It is particularly notable that a substantial number of studies were dedicated for the development of air-conditioning and power recovery systems for electric vehicles in this year. (4) In building mechanical system research fields, seventeen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the evaluation of work noise in tunnel construction and the simulation and development of a light-shelf system. The subjects of building energy were worked on the energy saving of office building applied with window blind and phase change material(PCM), a method of existing building energy simulation using energy audit data, the estimation of thermal consumption unit of apartment building and its case studies, dynamic window performance, a writing method of energy consumption report and energy estimation of apartment building using district heating system. The remained studies were related to the improvement of architectural engineering education system for plant engineering industry, estimating cooling and heating degree days for variable base temperature, a prediction method of underground temperature, the comfort control algorithm of car air conditioner, the smoke control performance evaluation of high-rise building, evaluation of thermal energy systems of bio safety laboratory and a development of measuring device of solar heat gain coefficient of fenestration system.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.10
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• pp.1378-1387
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• 2012

To investigate the pharmacological activity of chaga mushroom (Inonotus obliquus) on extraction conditions, chaga was extracted using water (reflux at $50^{\circ}C$, decoction over $90^{\circ}C$, pressure at $121^{\circ}C$) or ethanol (reflux at 50, 70, or $90^{\circ}C$). When water extract was further fractionated into crude polysaccharide (IO-CP), yields of IO-CP (4.8~16.8%) were higher than those of ethanolic extracts (IO-E, 1.9~2.7%) at increased temperature. For antioxidant activity, crude polysaccharide (IO-CP-121) obtained by pressurized extraction showed the highest polyphenolic and flavonoid contents (35.10 mg TAE/g and 18.48 mg QE/g, respectively) as well as DPPH and ABTS free radical scavenging activities (26.08 and 27.99 mg AEAC/100 mg, respectively). Meanwhile, IO-CP-D (decoction) and IO-CP-50 (reflux) had more potent mitogenic effects (2.10- and 1.95-fold of saline control at 100 ${\mu}g/mL$) as well as intestinal immune system modulating activities (6.30- and 5.74-fold) compared to IO-CP-121, whereas ethanolic extracts showed no activity. Although no IO-CP showed cytotoxicity against RAW 264.7 cells at 0.1 mg/mL, IO-CP-121 significantly inhibited TNF-${\alpha}$ and NO production as pro-inflammatory factors in LPS-stimulated RAW 264.7 cells (29.2 and 63.5%, respectively). Ethanolic extracts also showed no cytotoxicity at 0.1 mg/mL, whereas inhibition of TNF-${\alpha}$ and NO production was significantly low compared to that of IO-CP-121. In addition, active IO-CP-D was further fractionated into an unadsorbed (IO-CP-I) and seven adsorbed fractions (IO-CP-II~VIII) by DEAE-Sepharose CL-6B column chromatography in order to isolate immunostimulating polysaccharide. IO-CP-II showed the most potent mitogenic effect and macrophage stimulating activity (4.51- and 1.64-fold, respectively). IO-CP-II mainly contained neutral sugars (61.86%) in addition to a small amount of uronic acid (2.96%), and component sugar analysis showed that IO-CP-II consisted mainly of Glc, Gal, and Man (molar ratio of 1.00:0.55:0.31). Therefore, extraction conditions affect the physiological activity of chaga, and immunostimulating polysaccharide fractionated from chaga by decoction is composed mainly of neutral sugars.

• Journal of Bio-Environment Control
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• v.30 no.4
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• pp.351-358
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• 2021

The study was investigated to compare growth characteristics, the antioxidant activity, and the triterpenoid content of two Centella asiatica cultivars ('Giant Tiger Care' and 'Good Tiger Care'). At 41 days after transplanting, lengths of leaf and petiole were significantly longer in 'Good Tiger Care' than in 'Giant Tiger Care'. However, the growth characteristics (leaf area, petiole thickness, petiole length, and weight) were greater in 'Giant Tiger Care' than in 'Good Tiger Care' at 104 days after transplanting (harvest time). Antioxidant activity and total phenol content in four extracts (WE, water extract; HWE, hot water extract; 50E, 50% EtOH extract; 70E, 70% EtOH extract) of the two cultivars were high in 70E of 'Giant Tiger Care'. As a result of the triterpenoids analysis, the major triterpenoids of the two cultivars were identified as madecassoside and asiaticoside. The total triterpenoid content was high in 50E and 70E of 'Giant Tiger Care' and 'Good Tiger Care', respectively but the total triterpenoid content was highest in Good Tiger Care'. However, at the 104 days after planting, the yield of 'Giant Tiger Care' was three times higher than that of 'Good Tiger Care'. In addition, the total triterpenoid content that can be produced in the same cultivation area (3.3m²) was 2.459mg in 50E of 'Giant Tiger Care', which was ~2.2times higher than that of 70E of 'Good Tiger Care' (1.103 mg). Thus, it is considered economical to cultivate 'Giant Tiger Care' which has the highest antioxidant activity and high total triterpenoid production per cultivation area.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.4 s.27
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• pp.293-300
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• 2006

Domestic laws such as Korea Marine Pollution Prevention Law (KMPPL) which has been mae and amended according to the conclusions and amendments of various international conventions for the prevention a marine pollution such as MARPOL 73/78 were reviewed and compared with the major contents of the relevant international conventions. Alternative measures for legislating new laws or amending existing laws such as KMPPL for the acceptance of major contents of existing international conventions were proposed. Annex VI of MARPOL 73/78 into which the regulations for the prevention of air pollution from ship have been adopted has been recently accepted in KMPPL which should be applied to ships which are the moving sources of air pollution at sea rather tlnn in Korea Air Environment Conservation Law which should be applied to automobiles and industrial installations in land. The major contents of LC 72/95 have been accepted in KMPPL However, a few of substances requiring special care in Annex II of 72LC, a few of items in characteristics and composition for the matter in relation to criteria governing the issue of permits for the dumping of matter at sea in Annex III of 72LC, and a few of items in wastes or other matter that may be considered for dumping in Annex I of 96 Protocol have not been accepted in KMPPL yet. The major contents of OPRC 90 have been accepted in KMPPL. However, oil pollution emergency plans for sea ports and oil handling facilities, and national contingency plan for preparedness and response have not been accepted in KMPPL yet. The waste oil related articles if Basel Convention, which shall regulate and prohibit transboundary movement of hazardous waste, should be accepted in KMPPL in order to prevent the transfer if scrap-purpose tanker ships containing oil/water mixtures and chemicals remained on beard from advanced countries to developing and/or underdeveloped countries. International Convention for the Control if Harmful Anti-Fouling Systems on the Ships should be accepted in KMPPL rather tlnn in Korea Noxious Chemicals Management Law. International Convention for Ship's Ballast Water/Sediment Management should be accepted in KMPPL or by a new law in order to prevent domestic marine ecosystem and costal environment from the invasion of harmful exotic species through the discharge of ship's ballast water.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.1
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• pp.16-37
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• 2018

In this study, difference in chemical composition of $PM_{2.5}$ observed between the year 2013 and 2015 at six air quality intensive monitoring stations (Bangryenogdo (BR), Seoul (SL), Daejeon (DJ), Gwangju (GJ), Ulsan (US), and Jeju (JJ)) was investigated and the possible factors causing their difference were also discussed. $PM_{2.5}$, organic and elemental carbon (OC and EC), and water-soluble ionic species concentrations were observed on a hourly basis in the six stations. The difference in chemical composition by regions was examined based on emissions of gaseous criteria pollutants (CO, $SO_2$, and $NO_2$), meteorological parameters (wind speed, temperature, and relative humidity), and origins and transport pathways of air masses. For the years 2013 and 2014, annual average $PM_{2.5}$ was in the order of SL ($${\sim_=}DJ$$)>GJ>BR>US>JJ, but the highest concentration in 2015 was found at DJ, following by GJ ($${\sim_=}SJ$$)>BR>US>JJ. Similar patterns were found in $SO{_4}^{2-}$, $NO_3{^-}$, and $NH_4{^+}$. Lower $PM_{2.5}$ at SL than at DJ and GJ was resulted from low concentrations of secondary ionic species. Annual average concentrations of OC and EC by regions had no big difference among the years, but their patterns were distinct from the $PM_{2.5}$, $SO{_4}^{2-}$, $NO_3{^-}$, and $NH_4{^+}$ concentrations by regions. 4-day air mass backward trajectory calculations indicated that in the event of daily average $PM_{2.5}$ exceeding the monthly average values, >70% of the air masses reaching the all stations were coming from northeastern Chinese polluted regions, indicating the long-range transportation (LTP) was an important contributor to $PM_{2.5}$ and its chemical composition at the stations. Lower concentrations of secondary ionic species and $PM_{2.5}$ at SL in 2015 than those at DJ and GJ sites were due to the decrease in impact by LTP from polluted Chinese regions, rather than the difference in local emissions of criteria gas pollutants ($SO_2$, $NO_2$, and $NH_3$) among the SL, DJ, and GJ sites. The difference in annual average $SO{_4}^{2-}$ by regions was resulted from combination of the difference in local $SO_2$ emissions and chemical conversion of $SO_2$ to $SO{_4}^{2-}$, and LTP from China. However, the $SO{_4}^{2-}$ at the sites were more influenced by LTP than the formation by chemical transformation of locally emitted $SO_2$. The $NO_3{^-}$ increase was closely associated with the increase in local emissions of nitrogen oxides at four urban sites except for the BR and JJ, as well as the LTP with a small contribution. Among the meterological parameters (wind speed, temperature, and relative humidity), the ambient temperature was most important factor to control the variation of $PM_{2.5}$ and its major chemical components concentrations. In other words, as the average temperature increases, the $PM_{2.5}$, OC, EC, and $NO_3{^-}$ concentrations showed a decreasing tendency, especially with a prominent feature in $NO_3{^-}$. Results from a case study that examined the $PM_{2.5}$ and its major chemical data observed between February 19 and March 2, 2014 at the all stations suggest that ambient $SO{_4}^{2-}$ and $NO_3{^-}$ concentrations are not necessarily proportional to the concentrations of their precursor emissions because the rates at which they form and their gas/particle partitioning may be controlled by factors (e.g., long range transportation) other than the concentration of the precursor gases.

• Journal of Food Hygiene and Safety
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• v.28 no.1
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• pp.69-74
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• 2013

This study has been performed for 150 days from February 1 - June 31, 2012 aiming at analyzing biologically hazardous factors in order to develop HACCP system for the vinegared pickle radishes. A process chart was prepared as shown on Fig. 1 by referring to manufacturing process of manufacturer of general vinegared pickle radishes regarding process of raw agricultural products of vinegared pickle radishes, used water, warehousing of additives and packing material, storage, careful selection, washing, peeling off, cutting, sorting out, stuffing (filling), internal packing, metal detection, external packing, storage and consignment (delivery). As a result of measuring Coliform group, Staphylococcus aureus, Salmonella spp., Bacillus cereus, Listeria Monocytogenes, E. coli O157:H7, Clostridium perfringens, Yeast and Mold before and after washing raw radishes, Bacillus cereus was $5.00{\times}10$ CFU/g before washing but it was not detected after washing and Yeast and Mold was $3.80{\times}10^2$ CFU/g before washing but it was reduced to 10 CFU/g after washing and other pathogenic bacteria was not detected. As a result of testing microorganism variation depending on pH (2-5) of seasoning fluid (condiment), pH 3-4 was determined as pH of seasoning fluid as all the bacteria was not detected in pH3-4. As a result of testing air-borne bacteria (number of general bacteria, colon bacillus, fungus) depending on each workplace, number of microorganism of internal packing room, seasoning fluid processing room, washing room and storage room was detected to be 10 CFU/Plate, 2 CFU/Plate, 60 CFU/Plate and 20 CFU/Plate, respectively. As a result of testing palm condition of workers, as number of general bacteria and colon bacillus was represented to be high as 346 $CFU/Cm^2$ and 23 $CFU/Cm^2$, respectively, an education and training for individual sanitation control was considered to be required. As a result of inspecting surface pollution level of manufacturing facility and devices, colon bacillus was not detected in all the specimen but general bacteria was most dominantly detected in PP Packing machine and Siuping machine (PE Bulk) as $4.2{\times}10^3CFU/Cm^2$, $2.6{\times}10^3CFU/Cm^2$, respectively. As a result of analyzing above hazardous factors, processing process of seasoning fluid where pathogenic bacteria may be prevented, reduced or removed is required to be controlled by CCP-B (Biological) and threshold level (critical control point) was set at pH 3-4. Therefore, it is considered that thorough HACCP control plan including control criteria (point) of seasoning fluid processing process, countermeasures in case of its deviation, its verification method, education/training and record control would be required.