• 한국신재생에너지학회:학술대회논문집
• /
• 2009.11a
• /
• pp.571-571
• /
• 2009

지열은 날씨와 기온 등에 영향을 받지 않고 연중 가동할 수 있어 기저부하를 담담할 수 있는 유일한 신재생에너지 자원이므로 이에 대한 기술개발이 시급하다. 우리나라는 비화산지대이며 지중 온도가 가장 높은 지역의 5km에서 약 $170^{\circ}C$ 내외이므로 외국에 비해 지온경사도가 크지 않은 편이다. 그리고 3km 이상에서는 지하대수층이 거의 존재하지 않기 때문에 지열발전을 위해서는 EGS 기법을 도입할 수 밖에 없는 실정이다. 그리고 지열수를 확보할 수 있는 온도범위가 약 $100{\sim}150^{\circ}C$ 정도이므로 이에 적합한 지열발전 플랜트를 선정할 필요가 있다. 일반적으로 지열발전에 적용되는 플랜트는 건증기 지열발전, 플래쉬증기 지열발전, 바이너리 사이클 지열발전으로 분류할 수가 있으나 국내 여건에 맞는 방식으로서 바이너리 사이클 발전으로서 ORC 플랜트 또는 Kalina 사이클 플랜트가 적합하므로 이에 대한 기술 개발이 적극적으로 이루어져야 한다. 따라서 국내 지열발전의 기술개발에 있어서 핵심요소는 심부천공 및 EGS를 위한 인공파쇄기술과 지상 플랜트로서 저온지열 발전 플랜트의 기술확보가 필요한 실정이다. 이와 같은 기술개발이 완성되면 발전 뿐만아니라 집단지역난방, 온실 및 양어장 등에도 열공급이 가능한 열병합발전이 가능하게 될 것이다. 또한, EGS 기술로서 상업적 성공을 이룬 것은 세계적으로 2~3개 사례에 불과한 신기술로서, EGS 기술의 국내 조기 실현으로 기술 선점 및 해외 수출을 모색할 필요가 있다. 그리고 심부 지열자원은 국내 어디에나 부존하는 ubiquitous 자원이며 이산화탄소 배출이 전무한 청정 국산 에너지 자원이나, 이의 개발에는 높은 초기 투자비와 risk를 요하므로 민간 업체의 투자가 제약을 받는다. 따라서 정부의 적극적인 지원하에 산.학.연 중심으로 시범보급이 우선 이루어진 후 민간의 자발적 투자를 통한 지열 개발을 유도할 필요가 있다.

• Proceedings of the Korea Society of Environmental Biology Conference
• /
• 2002.11a
• /
• pp.163-176
• /
• 2002

광양만 및 주변해역의 참굴을 대상으로 환경생체지표를 측정하여 환경독성을 조사하였다. 광양만에서는 세포치사독성은 나타나지 않았으며, 라이소솜의 안정성은 남해도 주변정점은 70%내외 인데 반해서, 기준정점의 50% 내외의 상대적으로 낮은 안정성을 보인다. 에스테라제 활성은 광양내만 및 태인교 부근의 정점과 남해도의 정점 8, 9 들은 63-88 FU 정도로 낮아서 활성이 저해 받고 있음을 알 수 있다. 이중나선 DNA의 함량은 남해도의 정점들은 150 FU 내외의 값을 보이고, 광양만은 130FU 내외로 함량이 낮고, 정점간의 차이가 크지 않다. 전체적으로 기준정점 및 외양역의 정점 10은 독성물질에 의한 영향이 적은 데 반해서, 광양만은 독성물질에 의해서 특히 라이소솜 온전성, 에스테라제 활성 등에 영향을 받고 있는 것으로 사료된다. 그리고 남해도 주변의 인근해역은 광양만에 비해서는 적은 영향을 받고있는 것으로 사료된다. 다른 측정자료와 비교하여 볼 때 광양만지역은 거제도와 같은 청정해역보다는 독성물질의 영향을 더 받았고, 마산과 같은 극심하게 오염된 지역보다는 독성물질의 영향을 적게 받았다. 인접한 가막만과 유사하거나 조금 더 독성물질의 오염에 의한 영향을 나타내는 것으로 사료된다. 퇴적물 독성실험에서 200 mg/ml(이하 mg)이상의 농도에서 전정점에서 100 mg에서 부분적 및 세포치사독성이 나타났으며, 라이소솜 안정성은 50 mg에 노출 했을 때에는 정점, 12, 20, 26, 42 에서는 25% 내외의 낮은 값을 보이고, 대부분의 정점에서 50 % - 70% 내외의 온전성을 보인다. 에스테라제 활성은 100 mg에 노출했을 때 묘도와 광양제철 인근에 위치한 정점 10, 12, 16, 22에서는 50 %내외의 값을 보였고(정점 22: 36%로 최저), 내만에 위치한 정점들에서는 60% 내외의 활성을 보였다. 양식장이 있는 정점 2, 외양의 영향을 많이 받는 정점 46, 51, 54 등은 활성 값이 70% 이상으로 퇴적물 독성이 상대적으로 낮았다. 이중나선 DNA 함량은 28.4 % - 49%로 대조군에 비해서 감소가 크다. 대부분의 정점이 대조군의 30% 내외로 정점 간의 차이는 크지는 않다. 그러나 다른 측정자료와 같이 정점 22에서 18%로 최소치를 나타내고, 정점 2, 12에서 20% 내외의 값을 보인다. 종합적으로 볼 때 오염물질의 유입이 크고, 광양제철 인근 정점 들이 모두 다른 정점에 비해서 낮아서, 퇴적물 독성이 높은 정점으로 조사되었다.

• Applied Chemistry for Engineering
• /
• v.16 no.4
• /
• pp.556-562
• /
• 2005

This study was performed to evaluate effects of pH and heavy metals on soil pollution in 167 sites of Gangwon-do. The overall pH range of soils was 4.3~8.4 The average soil pollution of Cd was 0.089 mg/kg (0.000~3.493 mg/kg), Cu 3.093 mg/kg (0.078~60.263 mg/kg), Pb 4.74 mg/kg (0.01~38.08 mg/kg), Hg 0.054 mg/kg (0.002~1.050 mg/kg), and As 0.971 mg/kg (0.031~77.051 mg/kg), but $Cr^{6+}$ was not detected in these soils. The average concentration of heavy metals in these soils was acceptable under the preliminary standard of soil preservation acts in Korea.

• Journal of the Economic Geographical Society of Korea
• /
• v.18 no.4
• /
• pp.522-538
• /
• 2015

The objective of this study was to review how contract farming started in Gochang-gun and identified its characteristics among the contracting parties and the consequent changes in the region's dairy industry with regard to the contract production of organic milk in Gochang-gun, Jeollabuk-do, Korea in conjunction with the Maeil Dairy Industry Corporation. The contract was established in keeping with the product diversification strategy of the company after a crisis due to opening of the market, taking advantage of the clean environment of Gochang-gun and positive attitudes of the local government and dairy farmers. The expansion of the participating farms led to a production gap among dairy farms in the region; however, the overall concern over the conventional practice of contract farming was mitigated as the organic farming spread with the conversion of the contract farms to organic farms.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.7 no.7
• /
• pp.1563-1568
• /
• 2003

The introduction of invasive marine species of living things into new environments by ship's ballast water, attached to ships' hulls and via other vectors has been identified as one of the four greatest threats to the world's oceans by Global Environment Facility(GEF). Making use of the new technology of alpha-AL$_2$O$_3$ dielectric barrier layer, the strong electric-field gas discharge was introduced and obtained between micro-gap electrodes at high pressure (∼105㎩) of $O_2$ in air and $H_2O$ in seawater. The mixed air with $H_2O$ could be ionized and dissociated into large numbers of activated particles of OH, $O_2$＋, O(1D), HO$_2$ and so on, and then dissolved into the ballast water to form dissolved hydroxyl radical with the concentration of ∼20mg/L. Therefore, the invasive marine species was treated effectively through the hydroxyl radical dissolved pipeline of ballast water by strong electric -field discharge.

• Journal of the Korean earth science society
• /
• v.21 no.3
• /
• pp.287-301
• /
• 2000

In order to investigate the factors and processes affecting the vertical distributions of ozone, we analyzed the ozone profile data measured using ozonesonde from 1995 to 1997 at Pohang city, Korea. In the course of our study, we analyzed temporal and spatial distribution characteristics of ozone at four different heights: surface (100m), troposphere (10km), lower stratosphere (20km), and middle stratosphere (30km). Despite its proximity to a local, but major, industrial complex known as Pohang Iron and Steel Co. (POSCO), the concentrations of surface ozone in the study area were comparable to those typically observed from rural and/or unpolluted area. In addition, the findings of relative enhancement of ozone at this height, especially between spring and summer may be accounted for by the prevalence of photochemical reactions during that period of year. The temporal distribution patterns for both 10 and 20km heights were quite compatible despite large differences in their altitudes with such consistency as spring maxima and summer minima. Explanations for these phenomena may be sought by the mixed effects of various processes including: ozone transport across two heights, photochemical reaction, the formation of inversion layer, and so on. However, the temporal distribution pattern for the middle stratosphere (30km) was rather comparable to that of the surface. We also evaluated total ozone concentration of the study area using Brewer spectrophotometer. The total ozone concentration data were compared with those derived by combining the data representing stratospheric layers via Umkehr method. The results of correlation analysis showed that total ozone is negatively correlated with cloud cover but not with such parameter as UV-B. Based on our study, we conclude that areal characteristics of Pohang which represents a typical coastal area may be quite important in explaining the distribution patterns of ozone not only from surface but also from upper atmosphere.

• Korean Journal of Environment and Ecology
• /
• v.27 no.4
• /
• pp.487-497
• /
• 2013

This study was conducted to suggest vegetation management plan for Gugok landscape maintenance and improvement by deducing the vegetation landscape factors inherent in Yongha Gugok and understanding vegetation structure through the investigate of existing vegetation and plant community structure of Yongha valley in Woraksan National Park. There were broad and flat rocks, natural layered stones, clear water, light stones, stream, valleys, waterfalls, Pinus densiflora and Acer pseudosieboldianum as a result of deducing natural factors on poetry. There were P. densiflora and A. pseudosieboldianum appeared as one of main vegetation landscape elements. The actual vegetation analysis results were as followed. The natural vegetation occupied 67.5% and it was classified as P. densiflora community, Quercus variabilis community, Q. variabilis-P. densiflora community, Q. variabilis-Q. serrata community, Q. serrata community, Q. mongolica community, Q. mongolica-P. densiflora community, Deciduous broad-leaved tree community. The artificial vegetation(18.7%) was classified as Q. serrata community-Larix kaempferi community, Q. mongolica- Castanea crenata community, L. kaempferi community, L. kaempferi-C. crenata community, fruticeta, L. kaempferi-Q. mongolica community. The grassland area(2.0%) was classified as Miscanthus sinensis community, Phragmites communis community, and other areas were classified as landscape tree planting area, farm, orchard, residential area. The representative vegetation were P. densiflora community, Q. variabilis-Q. serrata community, L. kaempferi community, Deciduous broad-leaved tree community in Yongha Gugok. The species diversity index of Shannon was 0.6274~0.9908 on the whole. Yongha Gugok, as a symbol of succession on confucianism and reverence for nature, should be preserved natural valley landscape being clean and wijungchuksa at the end of Joseon Dynasty and Japanese Colonial era. In this historical and cultural Gugok, vegetation landscape management plan is needed to landscape maintenance with P. densiflora community, density control with L. kaempferi community. And it is considered when natural disasters and artificial damages happened, P. densiflora-oriented vegetation restoration plan should be applied in order to restore.

• Journal of the Korean earth science society
• /
• v.22 no.4
• /
• pp.327-338
• /
• 2001

In this study, the short-term variability of methane concentrations were investigated over 24-hr scale. The data obtained form the Moo-Ahn (MAN) station located in the western coastal area of Korea were analyzed from various respects to describe its distribution characteristics over short term scale. The MAN data were compared with those obtained from the two major background observatory sites: Point Barrow (Alaska) and Mauna Loa (Hawaii). The mean concentration of methane for the whole study period, when computed using the daily mean values, was found to be 1898${\pm}$85.3ppb (N=812). The mean values for the two comparable sites were observed to be 1832${\pm}$29.6ppb (N=823) for Point Barrow and 1745${\pm}$14.8ppb (N=818) for Mauna Loa. According to the analysis of frequency distribution. the mode value for the MAN area is found to be 1900ppb, but the mean concentration for Point Barrow and Mauna Loa are shown to have relatively low values of 1850 and 1750ppb, respectively. When examined over diurnal scale, the CH$_4$data for the MAN area exhibit a rather consistent trend; CH$_4$level is low during the daytime (after 6:00 A.M) and rises during the nighttime. The findings of the generally enhanced methane concentration in the MAN station may be explained form various respects. One of the most important reasons is that the MAN area is under the influence of various source processes relative to all the other stations under consideration. The short-term distribution patterns for the MAN station are hence characterized not only by the high methane concentration but also by the high oscillation in its CH$_4$concentration level.

• Korean Journal of Environment and Ecology
• /
• v.24 no.5
• /
• pp.556-565
• /
• 2010

Community analysis based on functional feeding groups of benthic macro invertebrates at Wangpi-cheon was assessed with the result of four field survey from October, 2007 to May, 2008. A total 138 species of benthic macro invertebrates in 58 families, 16 orders, 6 classes, and 4 phyla were collected during the field surveys. The result of EPT index value showed high value of 61.59% and it means that the stream ecosystem of Wangpi-cheon is very clear and healthy. In this study the functional feeding groups in Wangpi-cheon were divided into two groups. First, Scrapers and Collectors-Gathering group which is normally dominant in midstream showed higher dominance in main stream than tributary. Second, shredders group showed higher dominance in tributary than main stream like as the general characteristics of upriver. With the result of cluster analysis based on the similarity index, the study areas could be grouped into a natural area(A group) and an artificial disturbance area(B group; site 8 and 11) where embankment, bank and levee had been built near by. And also, the natural area(A group) was classified into two groups which had the characteristic of main(site 1, 2, 3, 4 and 7) stream and tributary(site 5, 6, 9 and 10) respectively.

• Journal of Life Science
• /
• v.20 no.3
• /
• pp.356-364
• /
• 2010

This study was carried out to investigate the exposure pathway of PBDEs in human breast milk collected from new mothers residing in Chuncheon, a comparatively clean area in Korea. The congeners of PBDE in 22 human breast milk samples were analyzed using a high resolution gas chromatography with a high resolution mass detector. The residue level of ${\sum}PBDEs$ was higher in primipara subjects than in multipara subjects (p<0.05). The levels in this study were similar to those of people in some Asian and European countries, but were lower than those of people in north America. In the congener profiles, BDE-47 (mean contribution=36.1%) was predominant, followed by BDE-153 (27%), BDE-99 (11.7%), BDE-100 (11.1%), BDE-28 (7.9%) and BDE-183 (3.5%). The sum of BDE-47 and BDE-153 accounted for more than 50% of ${\sum}PBDEs$ in most samples. BDE-47 was highly correlated with ${\sum}PBDEs$ (r=0.94, p<0.001). No strong trend was observed between PBDE levels and a number of key biological factors (women's age, weight, height and body mass index) examined in this study, however, weak correlations were observed in PBDE levels measured against dietary habits, particularly in fish consumption frequency. It seems that Korean people might be exposed to multiple sources including products of PBDEs, and particularly food resources.