• Journal of Korean Society of Forest Science
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• v.87 no.3
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• pp.404-414
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• 1998

The purpose of this study was to investigate the influence of air pollution using epiphytic lichens on forest trees around Ulsan and Onsan industrial complex from April to June, 1997. The distribution of lichens was investigated at 58 sampled sites. In this study, 16 kinds of epiphytic lichens were recorded, of them, Lepraria sp. having a tolerance to air pollution showed the highest frequency as 30.85%, and in order of Lecanora strobilina(26.18%) and Parmelia austrosinensis(13.42%) unknown to tolerance of air pollution. The number of lichens was gradually decreased around industrial complex, where so - called "lichen desert" was detected. As being distant from the industrial complex, the mean degrees of cover were increased. The degrees of cover in the investigated sites ranged from I to V. According to $SO_2$ concentration limiting lichen's growth, the pattern of distribution of Cladonia sp., Dirinaria applanata, Parmelia austrosinensis, Lepraia sp. and Lecanora strobilina were dissimilar by sensitivity to air pollution Especially Lepraria sp. and Lecanora strobilina were widely distributed to degree of cover from I to V, and as the both had a similar distribution pattern, it could be inferred that Lecanora strobilina had also a tolerance to air pollution. The IAP values ranging from 0 to 64.3 were arranged into six groups and the investigated area was delineated into six IAP zones to represent degree of air environment. It was a high IAP value as being distant from industrial complex. The mare IAP increased, the more number of kinds of lichens increased. It was confirmed that the number of species, coverage and IAP value of epiphytic lichens showed a tendency to decrease of urban area and industrial complex.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.12
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• pp.937-942
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• 2013

Fluid generated within the sonic or ultrasonic waves are reflected by the wall, while the opposite direction forming a predetermined sound wave to the acoustic standing wave is referred to. In this study, the frequency of 1.0 MHz and 2.0 MHz acoustic standing wave generation module is installed in a continuous particle separation device, the laminar flow of influent, taking into account the hydraulic retention time (HRT) in accordance with changes in particle separation characteristics investigated. Operation of a standing wave in the particle separation device about $1.3{\sim}2.8^{\circ}C$ temperature is increased, but did not significantly affect the formation of standing waves. During operation, the HRT 1 hr frequency 1.0 MHz 2 hr, 4 hr longer as the particle separation efficiency (turbidity) were 64.1%, 70.0%, 74.3% and, 2.0 MHz has 58.0%, respectively, depending on HRT, 61.8%, 70.7% in the respectively. That is, the same frequency, the HRT treatment efficiency is 10% or more, depending on differences in generation and, 1.0 MHz frequency, 2 hr, 2.0 MHz 4 hr at about 70% or more of the processing efficiency can be maintained. Frequency of 1.0 MHz and 2.0 MHz operation at the same time, as a result, HRT 1 hr, 2 hr, 4 hr particle separation efficiency of 63.8%, respectively, 70.6%, 77.6%, rather than the generation of standing waves appear continuous HRT is affecting a lot of particles to separate could know.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.6 no.1
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• pp.13-26
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• 2001

Six ferromanganese crusts from the Lomilik and Litatfooki seamounts in the Marshall Islands were analyzed for texture, geochemistry and stratigraphy to delineate the paleoceanographic conditions. The crusts can be divided into three layers; 1) outermost massive layer (Layer 1), 2) middle porous Fe-oxides rich layer infllled with biointemal clasts (Layer 2), and 3) innermost massive layer cemented and/or replaced by carbonate fluoapatite (CFA) (Layer 3). The Layer 1 contains higher Mn, Co, Ni, and Mg than other two layers, and the Layer 2 was relatively more enriched in Fe, Al, Ti, Ba, Cu, and Zn. However, the Layer 3 shows higher Ca and P and lower Mn, Fe, Co, and Ni contents than overlying two layers. Based on the Co-chronometry, the crusts are postulated to have begun to grow from 56-31 Ma (early Eocene to Oligocene). The boundaries between layers 1 and 2, and layers 2 and 3 are dated to be 7-3 Ma and 26-14 Ma, respectively. High contents of Ca and P in Layer 3 clearly indicate that the layer had been phosphatized prior to the formation of Layer 2. Considering the well-preserved mjcrostructures in Layer 3, it is unlike that the crusts themselves were recrystallized in suboxic condition. Also, the lower Co concentrations in Layer 3 may imply that the Co supply was not constant during the formation of Layer 3. Layer 2, characterized by the porous texture, grew over Layer 3 during 26-9 Ma. Internal biogenic sediments including foraminifera within the original cavities and the enrichment of organophillic elements such as Ba, Cu, and Zn, suggest that Layer 2 have below high production regions. Also, high content of allumino silicate components may indicate increased terrigeneous input during the formation of Layer 2. The Layer 2. The Layer 1 has been subjected to little diagenetic influence since the Pliocene.

• Korean Journal of Ecology and Environment
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• v.50 no.4
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• pp.459-469
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• 2017

Nitrogen (N) loading from domestic, agricultural and industrial sources can lead to excessive growth of macrophytes or phytoplankton in aquatic environment. Many studies have used stable isotope ratios to identify anthropogenic nitrogen in aquatic systems as a useful method for studying nitrogen cycle. In this study to evaluate the precision and accuracy of denitrification bacteria method (Pseudomonas chlororaphis ssp. Aureofaciens ($ATCC^{(R)}$ 13985)), three reference (IAEA-NO-3 (Potassium nitrate $KNO_3$), USGS34 (Potassium nitrate $KNO_3$), USGS35 (Sodium nitrate $KNO_3$)) were analyzed 5 times repeatedly. Measured the ${\delta}^{15}N-NO_3$ and ${\delta}^{18}O-NO_3$ values of IAEA-NO-3, USGS 34 and USGS35 were ${\delta}^{15}N:4.7{\pm}0.1$‰ ${\delta}^{18}O:25.6{\pm}0.5$‰, ${\delta}^{15}N:-1.8{\pm}0.1$‰ ${\delta}^{18}O:-27.8{\pm}0.4$‰, and ${\delta}^{15}N:2.7{\pm}0.2$‰ ${\delta}^{18}O:57.5{\pm}0.7$‰, respectively, which are within recommended values of analytical uncertainties. Also, we investigated isotope values of potential nitrogen source (soil, synthetic fertilizer and organic-animal manures) and temporal patterns of ${\delta}^{15}N-NO_3$ and ${\delta}^{18}O-NO_3$ values in river samples during from May to December. ${\delta}^{15}N-NO_3$ and ${\delta}^{18}O-NO_3$ values are enriched in December suggesting that organic-animal manures should be one of the main N sources in those areas. The current study clarifies the reliability of denitrification bacteria method and the usefulness of stable isotopic techniques to trace the anthropogenic nitrogen source in freshwater ecosystem.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.1
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• pp.1-16
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• 2007

The use of information on natural resources is indispensable to most agricultural activities to avoid disasters, to improve input efficiency, and to increase lam income. Most information is prepared and managed at a spatial scale called the "Hydrologic Unit" (HU), which means watershed or small river basin, because virtually every environmental problem can be handled best within a single HU. South Korea consists of 840 such watersheds and, while other watershed-specific information is routinely managed by government organizations, there are none responsible for agricultural weather and climate. A joint research team of Kyung Hee University and the Agriculture, forestry and Fisheries Information Service has begun a 4-year project funded by the Ministry of Agriculture and forestry to establish a watershed-specific agricultural weather information service based on "high definition" digital climate maps (HD-DCMs) utilizing the state of the art geospatial climatological technology. For example, a daily minimum temperature model simulating the thermodynamic nature of cold air with the aid of raster GIS and microwave temperature profiling will quantify effects of cold air drainage on local temperature. By using these techniques and 30-year (1971-2000) synoptic observations, gridded climate data including temperature, solar irradiance, and precipitation will be prepared for each watershed at a 30m spacing. Together with the climatological normals, there will be 3-hourly near-real time meterological mapping using the Korea Meteorological Administration's digital forecasting products which are prepared at a 5 km by 5 km resolution. Resulting HD-DCM database and operational technology will be transferred to local governments, and they will be responsible for routine operations and applications in their region. This paper describes the project in detail and demonstrates some of the interim results.

• Journal of Korean Society of Transportation
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• v.25 no.5
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• pp.125-133
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• 2007

Through open-sky policy, USA and European selected market principle of multiuser. However, in Asian case, major airlines monopolize airports. It is purpose that analyzes fare competition of Asian Hub Airport and the position of Incheon airport in Asia. Passengers required longer time and distance to go to the destination because direct flights decreases. But passengers increased in airport every year. Because of routes that decrease, airlines provide more services of flights. So airlines prefer to Hub Airports. As a result, both passengers and airlines are profitable by various routs and the increased frequency. On the assumption that distance and fare are related, the final formula is as following that defined the air fare from hub(H) to destination(Z) by logarithm. Analysis showed that log Rdist is not 1 but 0.08. As distance increases, fare doesn't increase. If distance from hub to destination airports is longer, Log dist_HZ is negative. It is that fare decreases from origin to destination via hub or that fare increases from hub to destination. HHI_HZ and HHI_AZ are negative. It means that if the degree of monopolization of hub and origin airports is lager, fare decreases from origin to destination via hub. Or fare increases from hub to destination. And it compares the Incheon airport with the other Asian hub airports and it examines the competitive fare by market division. As compared with the Incheon airport, Singapore, Beijing and Narita airports are higher fares. They compete with the other ones by Asian hub airports. But Hong Kong and Taipei airports must have more passengers through fare competition yet.

• Analytical Science and Technology
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• v.23 no.4
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• pp.371-382
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• 2010

TSP and PM2.5 atmospheric aerosols have been collected at Gosan site of Jeju Island, and their compositions were analyzed to understand the pollution characteristics. The composition ratios of nss (non-sea salt)-$SO_4^{2-}$ and $NH_4^+$ were higher in Gosan site than those in other Korean background and urban sites. However the composition ratio of $NO_3^-$ was conversely lower in Gosan site. From the study of aerosol components according to particle sizes, the anthropogenic nss-$SO_4^{2-}$, $NO_3^-$ and $NH_4^+$ components were mostly existed in the fine particles. But the nss-$Ca^{2+}$, $Na^+$, $Cl^-$ and $Mg^{2+}$ originated from soil and marine sources were distributed relatively in the coarse particles. In the seasonal comparison, the concentrations of nss-$Ca^{2+}$, Al, Fe, Ca and $NO_3^-$ increased in spring season, and nss-$SO_4^{2-}$ showed higher concentration in summer and spring seasons. Based on the factor analysis, the atmospheric aerosols in Gosan site have been found to be influenced largely by anthropogenic sources, and next by marine and soil sources. The backward trajectory analyses showed that the concentrations of nss-$SO_4^{2-}$, $NO_3^-$, Pb and nss-$Ca^{2+}$ increased when the air mass moved from Chinese continent to Jeju area. On the other hand, their concentrations decreased when the air mass moved in from the North Pacific Ocean.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.2
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• pp.178-184
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• 1992

The changes in contents of chlorophyll and free proline in the seedling leaves of ten rice cultivars as affected by salt stress were checked in order to obtain the basic information on the judgement of the degrees of salt injury. The difference in salt injury among the cultivars was clearly observed about 25 days after 6% salt treatment. Chlorophyll content was decreased in both Gayabyeo and Taebaegbyeo for 14 days after different salt treatment as salt concentration was increased and the decreased tendency was much higher in Taebaegbyeo than in Gayabyeo over 0.4% salt concentration. Chlorophyll content in Gayabyeo after 0.6% salt treatment was decreased slowly, while in Taebaegbyeo, deminished very rapidly as time progressed, therefore it decreased by about 16% in Gayabyeo and 67% in Taebaebyeo compared to the control at 20 days, respectively. The relationship between chlorophyll content and the degrees of salt injury in ten rice cultivars showed significant negative correlation at 10 day after 0.6% salt treatment. Free proline content in Gayabyeo was increased gradually for 14 days after different salt treatment as salt became higher, while in Taebaebyeo, it was increased rapidly under 0.6% but rather decreased under 0.8% salt concentration. Particularly, it was much higher Taebaegbyeo than in Gayabyeo under salt concentration from 0.4 to 0.6%. Free proline content in Gayabyeo after 0.6% salt treatment was increased from 15 days, on the other hand in Taebaegbyeo, it was increased from 5 days, but rather decreased from 20 days, and it was 6 times higher in Taebaegbyeo than in Gayabyeo at 10 days. There was significant positive correlation between free proline content and the degrees of salt injury in ten rice cultivars at 10 days after 0.6% salt treatment. From the above results, chlorophyll and free proline content may be used as an indicative character of intensity of salt stress as well as varietal difference in resistance to salt stress in the seedling stage.

• Journal of Animal Science and Technology
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• v.51 no.4
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• pp.337-342
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• 2009

The feasibility of reutilization of magnesium ammonium phosphate (MAP) or struvite slurry recovered from the process through microwave irradiation was studied in this experiment. For this purpose, 4 different operations were performed with or without Mg source addition and different levels of MAP recycled in a batch reactor. Dissolution rate of MAP, ${NH_4}^+$ elimination pattern and physicochemical changes of MAP during microwave irradiation were also studied. The result showed that only 33% orthophosphate ($PO_4-P$) and 27% $NH_4-N$ removal occurred without adding any external Mg source (run A), whereas 87% $PO_4-P$ and 40% $NH_4-N$ removed when 1.0 M ratio of $MgCl_2$ (run B) was added based on $PO_4-P$ in influent. Although the addition of 1.0 molar ratio of microwave irradiated MAP (Run C) removed lower $PO_4-P$ and $NH_4-N$ than 1.0 M $MgCl_2$ (run B), $PO_4-P$ removal was double when compared with no Mg addition (run A). Addition of half MAP and half $MgCl_2$ (run D) showed the similar removal efficiency (88% $PO_4-P$ and 35% $NH_4-N$) with sole $MgCl_2$ addition (run B). Based on these results, the reutilization of MAP irradiated by microwave would be a feasible way to enhance the removal efficiencies of N and P, as well as curtail the Mg chemical usage. Track study showed that $NH_4-N$ gradually increased at initial stage of microwave irradiation of MAP, and then started eliminating from liquor as temperature increased over $45^{\circ}C$. Dissolution rate of ${PO_4}^{-3}$ during microwave irradiation was proportional to the initial MAP concentration, having $0.0091x^{0.6373}$ mg/sec. It was found from the scanning electron microscope (SEM) study that physical structure of MAP crystal started breaking down into small cube granules within very short time by electromagnetic vibration force during microwave irradiation and then gradually melted down into solution.

• Korean Journal of Environmental Agriculture
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• v.28 no.2
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• pp.97-105
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• 2009

A constructed wetland which was composed of aerobic and anaerobic areas was evaluated for 3 years to effectively treat the sewage produced in farming and fishing communities. For 3 years in a constructed wetland, biochemical oxygen demand(BOD), chemical oxygen demand(COD), suspended solids(SS), total nitrogen(T-N), and total phosphorus(T-P) in effluent were 0.2${\sim}$11.8, 1.0${\sim}$41.9, 1.1${\sim}$6.5, 4${\sim}$60 and 0.02${\sim}$3.51 mg/L, respectively. Removal rate of BOD, COD and SS in effluent were 97, 92 and 99%, respectively, in the third year. As time goes by, removal rate of T-N and T-P in treated water in aerobic area and effluent were gradually increased in a constructed wetland. In the third year, removal rate in effluent were 62 and 73%, respectively. By the seasons, removal rate of BOD, COD, SS, T-N and T-P were 97${\sim}$98, 87${\sim}$91, 99, 43${\sim}$61 and 76${\sim}$86%, respectively. Removal rate of BOD, COD, SS and T-P were not affected by the seasons, but that of T-N in winter and spring were decreased than the other seasons.