• Korean Chemical Engineering Research
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• v.43 no.2
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• pp.206-214
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• 2005

Heterogeneously-catalyzed oxidation of aqueous phase trichloroethylene (TCE) over supported metal oxides has been conducted to establish an approach to eliminate ppm levels of organic compounds in water. A continuous flow reactor system was designed to effect predominant reaction parameters in determining catalytic activity of the catalysts for wet TCE decomposition as a model reaction. 5 wt.% $CoO_x/TiO_2$ catalyst exhibited a transient period in activity vs. on-stream time behavior, suggesting that the surface structure of the $CoO_x$ might be altered with on-stream hours; regardless, it is probable to be the most promising catalyst. Not only could the bare support be inactive for the wet decomposition reaction at $36^{\circ}C$, but no TCE removal also occurred by the process of adsorption on $TiO_2$ surface. The catalytic activity was independent of all particle sizes used, thereby representing no mass transfer limitation in intraparticle diffusion. Very low TCE conversion appeared for $TiO_2$-supported $NiO_x$ and $CrO_x$ catalysts. Wet oxidation performance of supported Cu and Fe catalysts, obtained through an incipient wetness and ion exchange technique, was dependent primarily on the kinds of the metal oxides, in addition to the acidic solid supports and the preparation routes. 5 wt.% $FeO_x/TiO_2$ catalyst gave no activity in the oxidation reaction at $36^{\circ}C$, while 1.2 wt.% Fe-MFI was active for the wet decomposition depending on time on-stream. The noticeable difference in activity of the both catalysts suggests that the Fe oxidation states involved to catalytic redox cycle during the course of reaction play a significant role in catalyzing the wet decomposition as well as in maintaining the time on-stream activity. Based on the results of different $CoO_x$ loadings and reaction temperatures for the decomposition reaction at $36^{\circ}C$ with $CoO_x/TiO_2$, the catalyst possessed an optimal $CoO_x$ amount at which higher reaction temperatures facilitated the catalytic TCE conversion. Small amounts of the active ingredient could be dissolved by acidic leaching but such a process gave no appreciable activity loss of the $CoO_x$ catalyst.

• Tunnel and Underground Space
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• v.32 no.5
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• pp.285-297
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• 2022

We report results of Extended Leak-Off Test (XLOT) conducted in a large diameter borehole, which is drilled for installation of deep borehole geophysical monitoring system to monitor micro-earthquakes and fault behavior of major fault zones in the southeastern Korean Peninsula. The borehole was planned to secure a final diameter of 200 mm (or more) at a depth of ~1 km, with 12" diameter wellbore to intermediate depths, and 7-7/8" (~200 mm) to the bottom hole depth. We drilled first the 12" borehole to approximately 504 m deep and installed American Petroleum Institute standard 8-5/8" casing, then annulus between the casing and bedrock was fully cemented. XLOT was carried out for several purposes such as confirming casing and cementing integrity, measuring rock stress states. To that end, we drilled additional 4 m long open hole interval to directly inject water and pressurize into the rock mass using the upper API casings. During the XLOT, flow rates and interval pressures were recorded in real time. Based on the logs we tried to analyze hydraulic conductivity of the test interval.

• Analytical Science and Technology
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• v.19 no.6
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• pp.535-543
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• 2006

Being used widely in semiconductor and display manufacturing, $NF_3$ is internationally considered as one of the regulated compounds in emission. Numerous companies have been continuously trying to reduce the emissions of $NF_3$ to comply with the global environmental regulation. This work is made to report the destruction and removal efficiency (DRE) of electrically heated scrubbers and the use rate in process chambers installed in three main LCD manufacturing companies in Korea. As the measurement techniques for $NF_3$ emission, mass flow controlled helium gas was continuously supplied into the equipment by which scrubber efficiency is being measured. The partial pressures of $NF_3$ and helium were accurately measured for each sample using a mass spectrometer, as it is emitted from inlet and outlet of the scrubber system. The results show that the DRE value for electrically heated scrubbers installed before 2004 is less than 52 %, while that for the new scrubbers modified based on measurement by scrubber manufacturer has been sigificentely improved upto more than 95 %. In additon, we have confirmed the efficiency depends on such variables as the inlet gas flow rate, water content, heater temperature, and preventative management period. The use rates of $NF_3$ in process chambers were also affected by the process type. The use rate of radio frequency source chambers, built in the $1^{st}$ and $2^{nd}$ generation process lines, was determined to be less than 75 %. In addition, that of remote plasma source chambers for the $3^{rd}$ generation was measured to be aboove 95 %. Therefore, the combined application of improved scrubber and the RPSC process chamber to the semiconductor and display process can reduce $NF_3$ emmision by 99.95 %. It is optimistic that the mission for the reduction of greenhouse gas emission can be realized in these LCD manufacturing companies in Korea.

• The Korean Journal of Quaternary Research
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• v.14 no.1
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• pp.7-31
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• 2000

Quaternary Geological and geophysical investigation was performed at the Eurimji reservoir of Jaechon City in order to interprete depositional environment and genesis of lake sediments. For this purpose, echo sounding, bottom sampling and columnar sampling by drilling on board and GPR survey were employed for a proper field investigation. Laboratory tests cover grain size population analysis, pollen analysis and $^{14}C$ datings for the lake sediments. The some parts of lake bottom sediments anthropogenically tubated and filled several times to date, indicating several mounds on the bottom surface which is difficult to explain by bottom current. Majority of natural sediments were accumulated both as rolling and suspended loads during seasonal flooding regime, when flash flow and current flow are relatively strong not only at bridge area of the western part of Eurimji, connected to stream valley, but at the several conduit or sewage system surrounding the lake. Most of uniform suspend sediments are accumulated at the lake center and lower bank area. Some parts of bottom sediments indicate the existence of turbid flow and mudflow probably due to piezometric overflowing from the lake bottom, the existence of which are proved by CM patterns of the lake bottom sediments. The columnar samples of the lake sediments in ER-1 and ER-3-1 boreholes indicate good condition without any human tubation. The grain size character of borehole samples shows poorly sorted population, predominantly composed of fine sand and muds, varying skewness and kurtosis, which indicate multi-processed lake deposits, very similar to lake bottom sediments. Borehole columnar section, echo sounding and GPR survey profilings, as well as processed data, indicate that organic mud layers of Eurimji lake deposits are deeper and thicker towards lower bank area, especially west of profile line-9. In addition the columnar sediments indicate plant coverage of the Eurimji area were divided into two pollen zones. Arboreal pollen ( AP) is predominant in the lower pollen zone, whreas non-aboreal pollen(NAP) is rich in the upper pollen zone. Both of the pollen zones are related to the vegetation coverage frequently found in coniferous and deciduous broad-leaved trees(mixed forest) surrounded by mountains and hilly areas and prevailing by aquatic or aquatic margin under the wet temperate climate. The $^{14}C$ age of the dark gray organic muds, ER1-12 sample, is 950$\pm$40 years B.P. As the sediments are anthropogenetically undisturbed, it is assumed that the reliability of age is high. Three $^{14}C$ ages of the dark gray organic muds, including ER3-1-8, ER3-1-10, ER3-1-11 samples, are 600$\pm$30 years B.P., 650$\pm$30 years B.P., 800$\pm$40 years B.P. in the descending order of stratigraphic columnar section. Based on the interpretation of depositional environments and formation ages, it is proved that Eurimji reservoir were constructed at least 950$\pm$40 years B.P., the calibrated ages of which ranges from 827 years, B.P. to 866 years B.P. Ancient people utilize the natural environment of the stream valley to meet the need of water irrigation for agriculture in the local valley center and old alluvium fan area.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.216-217
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• 2022

Gulpur 수력발전 프로젝트는 전력난을 겪고 있는 파키스탄에 102 MW 규모의 수력발전소를 건설하여 30년 동안 운영 관리한 후 파키스탄 정부로 양도하는 IPP(Independent Power Producing) 형식의 투자사업이다. 남동발전과 DL E&C, 롯데건설이 Sponsor로서 출자한 자본금과, ADB, IFC, K-EXIM 등의 대주단로부터의 차입금을 재원으로 하여 소요 사업비를 조달하고 사업을 개발하였다. DL E&C와 롯데건설이 EPC(Engineering, Procurement, Construction)를 수행하였고, 이산이 Design consultant의 역할을 수행하였다. Gulpur 수력발전 프로젝트의 발전형식은 수로식(run-of-river)으로 201 m³/s의 발전유량과 102 MW의 발전 시설용량을 이용하여 연평균예상발전량은 398 GWh이다. 주요 구조물로는 설계 재현빈도 1년의 유수전환시설(가물막이댐 & 가배수터널)과 콘크리트 중력식댐(H 67 m, L 205 m), 도수터널(D 6.7 m, L 215 m, 2기), 옥외형 발전소 (H 51 m, W 60 m, L 38 m, Kaplan 2기)가 있으며, 2015년 10월 착공하여 2020년 3월 상업발전을 시작하였다. 본 프로젝트는 DL E&C의 첫 번째 EPC 해외수력발전 프로젝트이다. 따라서 프로젝트의 성공적 수행을 위한 경제적 설계, 시공의 효율성 및 안정성 확보 등을 위하여 많은 연구를 수행하는 과정에서 다양한 기술 개선을 이룰 수 있었다. 본고에서는 Gulpur 프로젝트를 통하여 도출된 성공 사례들을 소개 및 공유하고자 한다. 첫 번째로 콘크리트 중력식댐 시공을 위한 유수전환시설의 최적 설계빈도를 산정하였다. 일반적으로 유수전환시설의 규모는 설계기준에 제시된 설계 재현빈도를 이용하는데, 해외 설계기준에서는 10년, 국내 설계기준에서는 1~2년으로 다르게 제시되어 있는 문제점이 있다. 유수전환시설의 규모는 프로젝트의 경제성에 큰 영향을 미치기 때문에 최적 설계빈도의 결정이 필요하며, 위험도분석기법(Risk Analysis)과 기대화폐가치법(Expected Monetary Value)을 이용하여 유수전환시설의 최적 설계 재현빈도와 이에 영향을 미치는 인자를 분석하였다. 위험도는 몬테카를로 시뮬레이션으로 산정된 가물막이댐 파괴확률과 재현빈도를 이용하여 산정된 가물막이댐 월류확률을 고려하였으며, 비용 및 피해액으로는 유수전환시설의 공사비, 가물막이댐 파괴시의 재건설비용과 지체보상금, 가물막이댐 월류시의 복구비용을 고려하였다. 이에 대한 연구결과로, 유수전환시설의 사용기간과 월류시의 복구비용이 유수전환시설의 설계 재현기간 결정에 가장 큰 영향을 미치는 것으로 나타났고, 특히 월류시의 복구비용이 작을수록 낮은 설계 재현빈도를 선택하는 것이 타당한 것으로 나타났다. 예를 들어, 유수전환시설의 사용기간이 3 ~ 5년, 복구비용이 0.5 ~ 1.0 mil USD 이하인 조건에서 가물막이시설의 최적 설계빈도는 1년 ~ 2년인 것으로 나타났다. 또한, 유수전환시설의 사용기간은 본댐의 규모와 시공기간 등을 고려하여 결정되는 사항으로 설계자가 임의 조정할 수 없지만, 복구비용은 시공 관리자에 따라 결정되는 부분으로, 적극적 홍수 피해 저감 및 복구방안을 마련하는 것이 프로젝트의 경제성을 향상시킬 수 있다는 것을 알 수 있었다. 두 번째로 프로젝트의 경제성 향상, 홍수기 댐 시공시의 안전성 확보를 위하여 홍수 조기경보시스템(Early Warning System)을 개발 및 활용하였다. 수로식(Run-of-river) 수력발전댐은 대부분 산악지역에 위치하기 때문에 국지성 강우 및 급한 지형 경사로 인하여 돌발홍수(flash flood)의 발생 가능성이 높다. 따라서 시공 중 홍수(월류) 발생을 미리 감지하고 현장에 전파할 수 있는, 수로식(Run-of-river) 수력발전댐 현장을 위한 홍수 조기경보시스템이 필요하며, 이를 리스크 인식, 모니터링 및 경보, 전파 및 연락, 반응 능력 향상의 4가지 부분으로 나누어 구축하였다. 리스크 인식 부분에서는 가물막이댐 월류 발생 상황에 대한 위험도, 취약성, 리스크를 제시하였으며, 모니터링 및 경보 부분에서는 상류 측정수위에서 유도된 현장 예상수위와 실제 현장 측정 수위를 대상으로 경보홍수위와 위험홍수위로 나누어 관리하였다. 전파 및 연락 부분에서는 현장 시공 조직을 활용하여 홍수시를 대비한 비상연락체계도(Emergency communication flow chart)를 운영하였으며, 반응 능력 향상을 위해 비상연락체계도의 팀별 Action plan을 상세화 하였다. 세 번째로 현장의 지질특성과 50여 차례 발파시험으로 현장 고유의 발파진동감쇄곡선을 도출하였으며, 이를 통해 현장의 시공성과 콘크리트 품질 확보를 동시에 달성할 수 있는 방안을 제시하였다. 콘크리트댐 공사에서는 제한된 공기 내에 공사를 완료하기 위해 사면부 굴착과 콘크리트 타설이 동시에 수행될 수밖에 없는 문제점을 가지고 있다. 그러나 신규 콘크리트 타설면 근처에서 발파를 수행하는 경우 발파로 발생되는 탄성파가 일정 수준을 초과하게 되면, 콘크리트 양생에 영향을 주게 된다. 따라서 다수의 현장 발파시험을 통해 발파거리와 최대진동속도의 상관관계 즉, 발파진동감쇄곡선을 도출함으로써 현장의 발파진동특성을 도출할 수 있었다. 또한, 기존 연구 논문들을 통해 콘크리트 재령기간 별 안전진동속도를 선정하고, 해당 안전진동속도를 초과하지 않는 범위에서 콘크리트 타설면과 발파위치의 거리에 따라 1회 발파 가능한 장약량을 산정하여 적용하였다. 이와 같은 체계적인 접근을 통해 콘크리트 타설과 발파 작업 동시 수행에 대한 논란을 해소할 수 있었다.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.15 no.1
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• pp.198-218
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• 2002

On the basis of Imjeungjinamuian(臨證指南醫案), authors investigated the pathogenesis and treatment of ophthalmotolaryngobgic diseases from the viewpoint of Onbyeong(溫病). 1. The symptoms and diseases investigated according to department were as follows;. 1) Ophthalmology : blepharitis, blepharedema, lacrimal hypersecretion, hyperemia, ophthalmalgla, photopsia, visual disturbance, mydriasis 2) Otology : full-feeling, otorrhea, otalgla, mastoiditis, tinnitus, hearing disturbance, vertigo 3) Rhinology : rhinorrhea, nasal obstruction, sinusitis, epistaxis 4) Laryngology : sore throat, hoarseness 5) The Others : headache, cough, asthma 2. The pathogenesis and treatment of ophthalmotolaryngologic diseases were as follows. 1) When the pathogenesis of hyperemia, otorrhea, otalgia, mastoiditis, hearing disturhance. epistaxis, sore throat, headache and cough are wind-stagnanc(風鬱), wind-warm(風溫), wind-fire(風火), wind-dryness(風燥), dryness-heat(燥熱), the treatment of pungent-cool-evaporating(辛凉解表) with Dajosan(茶調散), Mori Folium(桑葉), Lonicerae Flos(金銀花), Forsythiae Fructus(連翹), Viticis Fructus(蔓荊子), Prunellae Spica(夏枯草), Arctii Fructus(牛蒡子), etc can be applied. 2) When the pathogenesis of hoarseness, cough and asthma are cold(寒), cold with endogenous heat(寒包熱, 外冷內熱), water retention(水邪), fluid retention(伏飮), impairment of YangKi by overexertion(勞傷陽氣), the treatment of pungent-warm-evaporating(辛溫解表) with Mahaenggamseoktang(麻杏甘石湯), Socheongryongtang(小靑龍湯), Jeongryeokdaejosapyetang(정력대조사폐탕), Gyejitang(桂枝湯), Armeniacae Amarum Semen(杏仁), etc can be applied. 3) When the pathogenesis of photopsia, otorrhea, otalgia, rhinorrhea, sinusitis, epistaxis, sore throat, hoarseness, headache and cough are stagnancy-induced heat(鬱熱), wind-dryness(風燥), wind-heat(風熱), summer heat(暑熱), summer wind(暑風), insidious summer heat(伏暑), autumn heat(秋暑), autumn wind(秋風), autumn dryness(秋燥), dryness-heat(燥熱), heat in Ki system(氣分熱), insidious warm(溫伏), brain discharge by fire in Ki system(氣火 腦熱), heat in stomach(胃熱), endogenous fire by deficiency of Yin(陰虛內火), deficiency of Yin in stomach(胃陰虛), the treatment of Ki-cooling(淸氣) with Bangpungtongseongsan(防風通聖散), Ikweonsan(益元散), Gyejibaekhotang(桂枝白虎湯), Geumgwemaekmundongtang(금궤맥문동탕), Gyeongokgo(瓊玉膏), Sojae Semen Praeparatum(두시), Scutellariae Radix(黃芩), Phyllostachys Folium(竹葉), Adenophorae Radix(沙參), Mori Cortex(桑白皮), Fritillariae Cirrhosae Bulbus(貝母), etc can be applied. 4) When the pathogenesis of blepharitis, hyperemia, ophthalmalgia, full-feeling, otorrhea, otalgia, tinnitus, hearing disturbance, sinusitis, hoarseness, headache and cough are fire in liver(肝火), fire in gallbladder(膽火), ministerial fire in Soyang system(少陽相火), wind-stagnancy(風鬱), stagnancy-induced fire(鬱火), brain discharge by phlegm-fire(痰火 腦熱), the treatment of mediation(和解) with Gardeniae Fructus(梔子), Moutan Cortex(牧丹皮), Saigae Tataricae Cornu(羚羊角), Artemisiae Annuae Herba(靑蒿), Cyperi Rhizoma(香附子), Poria(적복령), etc can be applied. 5) When the pathogenesis of blepharedema and cough are dampness in both spleen and lung(脾肺濕) damp-heat(濕熱), damp-phlegm(濕痰), the treatment of dampness-resolving(化濕) with Poria(백복령), Coicis Semen(薏苡仁), Tetrapanacis Medulla(通草), Armeniacae Amarum Semen(杏仁), Talcum(滑石), etc can be applied. 6) When the pathogenesis of vertigo and cough are deficiency of Yong(營虛), heat in Yong, system(營熱), the treatment of Yong-cooling(淸營) with Rehmanniae Radix(生地黃), Liriopis Tuber(麥門冬), Biotae Semen(柏子仁), Lilii Bulbus(百合), Phyllostachys Folium(竹葉), etc can be applied. 7) When the pathogenesis of epistaxis are heat in blood system of heart(心血熱), reversed flow of fire(火上逆), overexertion(努力), the treatment of blood-cooling(凉血) with Rhinoceri Cornu(犀角), Rehmanniae Radix(生地黃), Moutan Cortex(牧丹皮), Salviae Miltiorrhizae Radix(丹參), Scrophulariae Radix(玄蔘), etc can be applied. 8) When the pathogenesis of nasal obstruction is pathogen-stagnancy(邪鬱), the treatment of resuscitation(開竅) with Sosang(少商, LU11) acupuncture can be applied. When the pathogenesis of hoarseness is evil Ki(穢濁), the treatment of resuscitation(開竅) with Arctii Fructus(牛蒡子), Lasiosphaera Seu Calvatia(馬勃), Curcumae Radix(鬱金), etc can be applied. When the pathogenesis of headache is stasis of both Ki and blood(氣血瘀痺), the treatment of resuscitation(開竅) with Cnidii Rhizoma(川芎), Asari Herba Cum Radice(細辛), Scorpio(全蝎), moxibustion(灸), etc can be applied. 9) When the pathogenesis of lacrimal hypersecretion, visual disturbance, mydriasis, tinnitus, hearing disturbance, sinusitis, epistaxis, hoarseness and cough are deficiency of Yin(陰虛), deficiency of kidney(腎虛), deficiency of both liver and kidney(肝腎虛), deficiency of both heart and kidney(心腎虛), brain discharge by deficiency of Yin(陰虛 腦熱), exuberance of Yang in liver(肝陽上亢), overexertion(勞損), the treatment of Yin-replenishing(滋陰) with Yukmijihwanghwan(六味地黃丸), Hojamhwan(虎潛丸), Jeobutang(猪膚湯), Lycii Fructus(枸杞子), Polygoni Multiflori Radix(何首烏), Rehmanniae Radix(生地黃), Schizandrae Fructus(五味子), Liriopis Tuber(麥門冬), Asini Gelatinum(阿膠), etc can be applied. 10) When the pathogenesis of ophthalmalgia, mydriasis, vertigo and headache are deficiency of Yin in liver(肝陰虛), exuberance of Yang in liver(肝陽上亢), endogenous wind(內風), excess in upper and deficiency in lower part(上實下虛), the treatment of Yin-replenishing(滋陰) and endogenous wind-calming(熄風) with Rehmanniae Radix Preparat(熟地黃), Lycii Fructus(枸杞子), Polygoni Multiflori Radix(何首烏), Paeoniae Radix Alba(白芍藥), Ostreae Concha(牡蠣), Saigae Tataricae Cornu(羚羊角), Chrysanthemi Flos(菊花), etc be applied. 11) When the pathogenesis of mydriasis, sinusitis, hoarseness, headache, cough and asthma are exhaustion of vital essence(精氣無收藏), brain discharge(腦髓不固), floating Yang(陽虛浮), exsanguination(失血), deficiency of both Yin and Yang(陰陽不足), overexertion(勞損), deficiency of Yang in kidney(腎陽虛), the treatment of Yang-restoring and exhaustion-arresting(回陽固脫) with Yangyeongtang(養營湯), Cheonjinhwan(天眞丸), Bokmaektang(복맥탕), Geonjungtang(建中湯), Dogihwan(都氣丸), Singihwan(腎氣丸), Jinmutang(眞武湯), Ostreae Concha(牡蠣), Nelumbinis Semen(蓮子肉), etc can be applied. 12) When the pathogenesis of lacrimal hypersecretion, vertigo and headache are deficiency of stomach and endogenous wind(胃虛內風), endogenous wind with phlegm(內風挾痰), liver check of stomach(肝木橫擾), the treatment of concomitant-treating of both liver and stomach(肝胃同治) with Paeoniae Radix Alba(白芍藥), Uncariae Ramulus Et Uncus(釣鉤藤), Gastrodiae Rhizoma(天麻), Astragali Radix(황기), Pinelliae Rhizoma(半夏), etc can be applied. When the pathogenesis of asthma is failure of kidney to promote inspiration(腎不納氣), the treatment of kidney-tonifing and inspiration-promoting(補腎納氣) with Singihwan(腎氣丸), Psoraleae Fructus(補骨脂), Juglandis Semen(胡桃), Aquilariae Resinatum Lignum(沈香), etc can be applied. When the pathogenesis of asthma is deficiency of Ki(氣虛), the treatment of Ki-reinforcing(補氣) with Sagunjatang(四君子湯), Insamgeonjungtang(人參建中湯), etc can be applied.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.5
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• pp.463-471
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• 2006

Electrical resistivity surveys were conducted at areas of abandoned landfills in Cheonan and Wonju. Geology and extent of leachate migration around the landfills were evaluated with collected resistivity data by 2-D and 3-D resistivity inverse modeling. The Cheonan landfill is located above the paddy fields and the resistivity survey lines were crossed to examine possible pollution at the paddy fields by leakage of the landfill leachate. In Wonju, the landfill and the downgradient paddy fields are divided by a concrete barrier wall. At the bottom of the landfill, there is a leachate settlement system, which has not been in operation. To evaluate leachate leakage into the paddy fields, a total of 4 survey lines were used. According to the resistivity survey results, the landfill leachate in Cheonan appeared to be restricted only within the interior of the landfill, not to migrate into the subsurface of the paddy fields. These results are well consistent with electrical conductivity values of groundwaters obtained from a periodic analysis of water qualities. In Wonju, however, it was inferred that the leachate emanating from the landfill migrated beneath the abandoned leachate settlement system and the leachate would reach the downgradient paddy fields. Low resistivity area was observed in the old reservoir area and it appeared to be derived from convergence of groundwater flows from the surrounding valley and the moist wet land. In addition, groundwater flow into the paddy fields occurs beneath the old reservoir embankment at depths of $7{\sim}8m$. This paper reports details of the resistivity surveys for the uncontrolled landfills.

• Journal of Soil and Groundwater Environment
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• v.6 no.3
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• pp.53-59
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• 2001

There is a lot of method to manage the insanitary landfill but vertical cutoff walls have been widespreadly used and were installed into the subsurface to act as a barrier to horizontal groundwater flow, The stabilized material such as specialized cement or mixed soil with additives has been generally applied for the materials of the deep soil mixing barrier in korea. The amount of the stabilized material is dependent on the field conditions, because the mixing ratio of the material and the field soil should achieve a requirement in the coefficient of permeability, lower than 1.0$\times$$10^{7}$cm/sec. This study determined the quantity and optimized function ratio of the stabilized material in the formation process of the mixed barrier that was added with stabilized material on the field soil classified into SW-SC under USCS (Unified Soil Classification System). After that the fly ash and lime were selected as an additives an that could improve the function of the stabilized material and then the method to improve the functional progress in the usage of putting into the stabilized material as an appropriate ratio was studied and reviewed. The author used the flexible-wall permeameter for measuring the permeability and unconfined compressive strength tester for compressive strength, and in the view of environmental engineering the absorption test of heavy metals and leaching test regulated by Korean Waste Management Act were performed. As the results, the suitable mixing ratio of the stabilized material in the deep soil mixing barrier was determined as 13 percent. To make workability easy, the ratio of stabilized material and water was proven to be 1 : 1.5. With the results, the range of the portion of the additives(fly ash : lime= 70 : 30) was proven to be 20-40% for improving the function of the stabilized material, lowering of permeability. In heavy metal absorption assessment of the mixing barrier system with the additives, the result of heavy metal absorption was proved to be almost same with the case of the original stabilized material; high removal efficiency of heavy metals. In addition, the leaching concentration of heavy metals from the leaching test for the environmental hazard assessment showed lower than the regulated criteria.

• Journal of Food Hygiene and Safety
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• v.29 no.2
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• pp.79-84
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• 2014

This study has been performed for about 270 days at analyzing biologically hazardous factors in order to develop HACCP system for the non heat-frozen carrot juice. A process chart was prepared by manufacturing process of raw agricultural products of non heat-frozen carrot juice, which was contained water and packing material, storage, washing, cutting, extraction of the juice, 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, Enterohemorrhagic E. coli before and after washing raw carrot, Standard plate count was $4.7{\times}10^4CFU/g$ before washing but it was $1.2{\times}10^2CFU/g$ detected after washing. As a result of testing airborne bacteria (Standard plate count, Coliform group, Yeast and Fungal) depending on each workplace, number of microorganism of in packaging room, shower room and juice extraction room was detected to be 10 CFU/Plate, 60 CFU/Plate, 20 CFU/Plate, respectively. As a result of testing palm condition of workers, as number of Standard plate count, Coliform group and Staphylococcus aureus was represented to be high as $6{\times}10^4CFU/cm^2$, $0CFU/cm^2$ and $0CFU/cm^2$, 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, Coliform group was not detected in all the specimen but Standard plate count was most dominantly detected in scouring kier, scouring kier tray, cooling tank, grinding extractor, storage tank and packaging machine-nozzle as $8.00{\times}10CFU/cm^2$, $3.0{\times}10CFU/cm^2$, $4.3{\times}10^2CFU/cm^2$, $7.5{\times}10^2CFU/cm^2$, $6.0{\times}10CFU/cm^2$, $8.5{\times}10^2CFU/cm^2$ respectively. As a result of analyzing above hazardous factors, processing process of ultraviolet ray sterilizing where pathogenic bacteria may be prevented, reduced or removed is required to be controlled by CCP-B (Biological) and critical level (critical control point) was set at flow speed is 4L/min. 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.

• Journal of Environmental Impact Assessment
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• v.31 no.4
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• pp.226-240
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• 2022

Local governments over a certain size in Republic of Korea may conduct Environmental Impact Assessment (EIA) considering regional characteristics if it is necessary, in accordance with Article 42 of the 「Environmental Impact Assessment Act」. However, it was investigated that the number of local government EIA operation in many local governments was less than initial expectations. In order to improve it, the status of ordinances and consultation guidelines which are different for each local government need to be compared, and the institutional issues forthe relevant local governments must be found considering regional characteristics. Furthermore, detailed regulation and guidance on the local government EIA procedure should be included in the consultation guidelines and related information need to be provided. In this study, focusing on the case of Incheon Metropolitan City, the status of local government EIA ordinances in metropolitan cities and provinces with a similar condition was investigated, and the types and scope of target projects were compared and analyzed. In addition, consultation guidelines forIncheon Metropolitan City were written, and improvements on the procedure flow and overall schedule designation derived from the process were presented. In the case of Incheon Metropolitan City, there were no detailed information officially announced regarding the regulations of the local government EIA ordinance and follow-up management, so the administrative system of the local government needed to be reinforced in this field. Meanwhile, considering the status of local environment and geography, some target project types were deemed necessary to be added: port construction projects, water resource development projects, railroad construction projects, and military facilities installation projects. The results of this study will provide useful information to local governments which want to improve their operation effectiveness by reorganizing the local government EIA system and preparing specific guidelines.