• 제목/요약/키워드: ground characterization

검색결과 183건 처리시간 0.025초

EU Water Framework Directive-River Basin Management Planning in Ireland

  • Earle, R.;Almeida, G.
    • Environmental Engineering Research
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    • 제15권2호
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    • pp.105-109
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    • 2010
  • The European Union (EU) Water Framework Directive (WFD) (2000/60/EC) was transposed into Irish law by Statutory Instrument Nos. 722 of 2003, 413 of 2005 and 218 of 2009, which set out a new strategy and process to protect and enhance Ireland's water resources and water-dependent ecosystems. The Directive requires a novel, holistic, integrated, and iterative process to address Ireland's natural waters based on a series of six-year planning cycles. Key success factors in implementing the Directive include an in-depth and balanced treatment of the ecological, economic, institutional and cultural aspects of river basin management planning. Introducing this visionary discipline for the management of sustainable water resources requires a solemn commitment to a new mindset and an overarching monitoring and management regime which hitherto has never been attempted in Ireland. The WFD must be implemented in conjunction with a myriad of complimentary directives and associated legislation, addressing such key related topics as flood/drought management, biodiversity protection, land use planning, and water/wastewater and diffuse pollution engineering and regulation. The critical steps identified for river basin management planning under the WFD include: 1) characterization and classification of water bodies (i.e., how healthy are Irish waters?), 2) definition of significant water pressures (e.g., agriculture, forestry, septic tanks), 3) enhancement of measures for designated protected areas, 4) establishment of objectives for all surface and ground waters, and 5) integrating these critical steps into a comprehensive and coherent river basin management plan and associated programme of measures. A parallel WFD implementation programme critically depends on an effective environmental management system (EMS) approach with a plan-do-check-act cycle applied to each of the evolving six-year plans. The proactive involvement of stakeholders and the general public is a key element of this EMS approach.

지하수위 변화에 따른 지하공동 주변의 지하수 유동특성 해석 (Groundwater Flow Characterization in the Vicinity of the Underground Caverns by Groundwater Level Changes)

  • 강재기;양형식;김경수;김천수
    • 터널과지하공간
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    • 제13권6호
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    • pp.465-475
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    • 2003
  • 본 논문은 지하공동이 건설되는 지역을 대상으로 공동내 지하수 유입량을 계산하기 위하여 영국의 AEA Technology에서 개발한 NAPSAC과 NAMMU를 이용하여 수치 모델링을 실시하였다. 이것은 3차원의 파쇄된 매질에서 지하수 유동에 대하여 아주 유효한 유한요소 소프트웨어 패키지이다. 모델링에 사용된 입력자료는 지표조사, 시추조사, 단일공 수리시험 자료 등을 이용하여 산출하였다. 공동내 지하수 유입량을 보다 정확히 산출하기 위하여 이방성 수리전도도를 고려하였으며 이방성 수리전도도값은 연구지역에 분포하는 균열체계의 확률적 분포특성이 반영된 균열망에서 역산되었다. 연속체 개념의 수치모델링을 통하여 평수기, 갈수기와 풍수기시의 지하 공동내 유입량, 유동시간, 유동경로의 변화를 계산하였다.

문경 탄산온천수의 지화학적 특성 및 침전물에 대한 광물학적 연구 (Water Geochemistry and Mineralogical Characterization of precipitate in the Munkyeong Bicarbonate Hot Spring)

  • 김정진;김윤영
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제7권2호
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    • pp.45-52
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    • 2002
  • 문경지역 온천은 칼슘-중탄산 온천으로 원수의 온도는 약 $28.5^{\circ}C$이다 원수는 EC(1,857 $\mu\textrm{s}$/cm), $HCO_3$ (1,250 mg/l), $SO_4$(147.60 mg/l), Mg(43.05 mg/l) . 그리고 Ca(279.43 mg/l)로 상당히 높은 값을 나타낸다. 원수에는 소량의 침전물이 형성되지만 보일러로 가열할 경우 많은 양의 침전물이 형성된다. 원수에서 침전되는 광물은 대부분 방해석이지만 보일러실에는 아라고나이트와 방해석이 동시에 정출된다. 온천수 내의 화학종은 $CO_3$는 대부분 $HCO_3^{-}$ 이지만 상당 부분이 $H_2$$CO_3$로, $SO_4$$SO_4^{2-}$ , Mg는 $Mg^{2+}$ Ca는$ Ca^{2+}$ 로 존재한다. 전체적으로 볼 때 대부분의 성분에서 $CO_3$를 포함한 화학종이 존재하는 것을 볼 수 있다. 포화지수를 근거로 침전 가능한 광물은 다이아스포어, 보에마이트, 깁사이트, 아라고나이트, 방해석, 능철석 등이지만 X-선회절 분석결과 침전물은 아라고나이트, 방해석, 철수산화물로 구성되어 있다.

Delamination and concrete quality assessment of concrete bridge decks using a fully autonomous RABIT platform

  • Gucunski, Nenad;Kee, Seong-Hoon;La, Hung;Basily, Basily;Maher, Ali
    • Structural Monitoring and Maintenance
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    • 제2권1호
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    • pp.19-34
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    • 2015
  • One of the main causes of a limited use of nondestructive evaluation (NDE) technologies in bridge deck assessment is the speed of data collection and analysis. The paper describes development and implementation of the RABIT (Robotics Assisted Bridge Inspection Tool) for data collection using multiple NDE technologies. The system is designed to characterize three most common deterioration types in concrete bridge decks: rebar corrosion, delamination, and concrete degradation. It implements four NDE technologies: electrical resistivity (ER), impact echo (IE), ground-penetrating radar (GPR), and ultrasonic surface waves (USW) method. The technologies are used in a complementary way to enhance the interpretation. In addition, the system utilizes advanced vision to complement traditional visual inspection. Finally, the RABIT collects data at a significantly higher speed than it is done using traditional NDE equipment. The robotic system is complemented by an advanced data interpretation. The associated platform for the enhanced interpretation of condition assessment in concrete bridge decks utilizes data integration, fusion, and deterioration and defect visualization. This paper concentrates on the validation and field implementation of two NDE technologies. The first one is IE used in the delamination detection and characterization, while the second one is the USW method used in the assessment of concrete quality. The validation of performance of the two methods was conducted on a 9 m long and 3.6 m wide fabricated bridge structure with numerous artificial defects embedded in the deck.

모르타르의 전기비저항 특성 (Mortar Characterization using Electrical Resistivity Method)

  • ;박삼규;송영수;김정호
    • 지구물리와물리탐사
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    • 제12권2호
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    • pp.215-220
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    • 2009
  • 시멘트 모르타르는 고속도로 건설 및 댐 사이트의 연약지반 보강과 석회암 공동의 지반보강에 널리 사용되고 있다. 모르타르의 물리적 성질은 많은 연구 결과로부터 잘 알려져 있지만, 연약지반의 개량 정도를 평가하기 위해서 알아야 할 가장 중요한 물성 중의 하나인 전기비저항에 대해서는 극히 일부의 연구만 수행되어 있다. 이 연구에서는 물과 포틀랜드 시멘트의 배합비(0.35, 0.45, 0.50, 0.65)를 달리하여 원통형의 모르타르 시료를 제작하여, 웨너 배열 방식으로 전기비저항을 측정하였다. 그 결과 모르타르 시료의 전기비저항은 경과시간에 따라 증가하였으며, 함수비와 물/시멘트의 배합비가 증가할수록 감소하였다. 이 결과로부터 모르타르의 전기비저항과 압축강도는 밀접한 관계를 가지고 있음을 알 수 있었다.

현장자료를 사용한 지반-구조물 상호작용에 대한 경험적 연구 (System Identification Analysis on Soil-Structure Interaction Using Field Data)

  • 김승현
    • 한국지반공학회논문집
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    • 제21권2호
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    • pp.37-46
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    • 2005
  • 최근 지진공학 제반분야의 연구동향은 지진발생시 구조물의 거동을 보다 합리적/경제적으로 고려하는 내진성능 목표 개념에 입각하여 많은 향상을 성취하고 있다. 특히, 실제 지진에서 관측된 자료를 사용하여 시방기준과 해석기법에 많은 보완이 이루어지고 있는 실정이다. 그러나, 지반-구조물 상호작용에 대한 연구는 경험적으로 입증된 해석방법의 정립이 아직까지 과제로 남아있는 분야이다. 이러한 취지에서, 본 연구에서는 구조물과 지표면 자유장 운동의 강진기록이 잘 관측되어 있는 2매 사이트를 선택하여, 입/출력 자료를 가지고 시스템 특성치즐 추정할 수 있는 System Identification 기법을 이용하여 지반-구조물 상호작용의 해석기법 중 가장 보편적이며 비교적 간단한 주파수 영역의 Impedance 함수를 계산하고 그 결과를 바탕으로 관성력에 의한 지반-구조물 상호작용에 대한 고찰을 수행한다.

Sonographic Pattern Recognition of Endometriomas Mimicking Ovarian Cancer

  • Saeng-Anan, Ubol;Pantasri, Tawiwan;Neeyalavira, Vithida;Tongsong, Theera
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권9호
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    • pp.5409-5413
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    • 2013
  • Background: To assess the accuracy of ultrasound in differentiating endometrioma from ovarian cancer and to describe pattern recognition for atypical endometriomas mimicking ovarian cancers. Materials and Methods: Patients scheduled for elective surgery for adnexal masses were sonographically evaluated for endometrioma within 24 hours of surgery. All examinations were performed by the same experienced sonographer, who had no any information of the patients, to differentiate between endometriomas and non-endometriomas using a simple rule (classic ground-glass appearance) and subjective impression (pattern recognition). The final diagnosis as a gold standard relied on either pathological or post-operative findings. Results: Of 638 patients available for analysis, 146 were proven to be endometriomas. Of them, the simple rule and subjective impression could sonographically detect endometriomas with sensitivities of 64.4% (94/146) and 89.7% (131/146), respectively. Of 52 endometriomas with false negative tests by the simple rule, 13 were predicted as benign masses and 39 were mistaken for malignancy. Solid masses and papillary projections were the most common forms mimicking ovarian cancer, consisting of 38.5% of the missed diagnoses. However, with pattern recognition (subjective impression), 32 from 39 cases mimicking ovarian cancer were correctly predicted for endometriomas. All endometriomas subjectively predicted for ovarian malignancy were associated with high vascularization in the solid masses. Conclusions: Pattern recognition of endometriomas by subjective assessment had a higher sensitivity than the simple rule in characterization of endometriomas. Most endometriomas mimicking ovarian malignancy could be correctly predicted by subjective impression based on familiarity of pattern recognition.

소나무 수피의 총합적 이용(제6보) -미분쇄 수피의 알칼리성 아황산염-안트라퀴논 증해와 증해폐액의 특성- (Utilization of Pine Bark(Part 6) -Alkaline Sulfite-Anthraquinone Cooking of Underground Bark and Characterization of the Spent Liquor-)

  • 문성필;박성천
    • 펄프종이기술
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    • 제32권4호
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    • pp.66-73
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    • 2000
  • Alkaline sulfite-anthraquinone(AS-AQ) cooking process has been applied to unground pine bark. The properties of the spent liquor such as molecular weight distributions, sulfonic equivalent weights, degree of sulfonation, phenolic hydroxyl groups and kaolin dispersing ability have been investigated to evaluate the possibility of using this liquor as concrete additives or binders. In the case of ground bark meal, more than 90% delignification was achieved at the optimal cooking conditions. However, applying these conditions on unground bark the delignification was slightly retarded. The decrease in the degree of delignification may be attributed to less penetration and diffusion of chemicals during the cooking of the bark. Increasing the cooking temperature only by $5^{\circ}C$ improved the delignification of the bark and about 90% delignification can be achieved. These results indicate that bark can be used successfully during AS-AQ cooking without any mechanical or physical pretreatment. The properties of lignin or polyphenol sulfonates in the spent liquor after AS-AQ cooking of the bark were compared with Sunflo-R, which is commercial lignosulfonate(CLS) prepared from wood. The weight average molecular weights(Mws) estimated by gel-filteration chromatography was found to be ranging from 1,200~1,800. These are considerably lower than those in CLS. Lignin or polyphenol sulfonates in the spent liquor of bark and CLS have similar degree of sulfonation, but the phenolic hydroxyl group was 1.8 times higher than CLS. Moreover, the dispersing abilities of the spent liquors were better than that of CLS, especially after 0.1% addition to kaolin suspension.

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임진강변 퇴적층 내 탄소물질들의 분포 및 특성 연구 (A Study on the Distribution and Property of Carbonaceous Materials in the Subsurface Sediments near the Imjin River)

  • 정상조
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제15권3호
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    • pp.34-43
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    • 2010
  • The fate of hydrophobic organic contaminants (HOCs) in ground water is highly affected by the distribution and property of the carbonaceous materials (CMs) in subsurface sediments. CMs in soils consist of organic matters (e.g., cellulose, fulvic acid, humic acid, humin, etc.) and black carbon such as char, soot, etc. The distribution and property of CMs are governed by source materials and geological evolution (e.g., diagenesis, catagenesis, etc.) of them. In this study, the distribution and property of CMs in subsurface sediments near the Imjin river in the Republic of Korea and HOC sorption property to the subsurface sediments were investigated. The organic carbon contents of sand and clay/silt layers were about 0.35% and 1.37%, respectively. The carbon contents of condensed form of CMs were about 0.13% and 0.45%, respectively. The existence of black carbon was observed using scanning electron microscopes with energy dispersive spectroscopy. The specific surface areas (SSA) of CMs in heavy fraction(HFrCM) measured with N2 were $35-46m^2/g$. However, SSAs of those HFrCM mineral fraction was only $1.6-4.3m^2/g$. The results of thermogravimetric analysis show that the mass loss of HFrCM was significant at $50-200^{\circ}C$ and $350-600^{\circ}C$ due to the degradation of soft form and condensed form of CMs, respectively. The trichloroethylene (TCE) sorption capacities of sand and clay/silt layers were similar to each other, and these values were also similar to oxidzed layer of glacially deposited subsurface sediments of the Chanute Air Force Base (AFB) in Rantoul, Illinois. However, these were 7-8 times lower than TCE sorption capacity of reduced layer of the Chanute AFB sediments. For accurate prediction of the fate of hydrophobic organic contaminants in subsurface sediments, continuous studies on the development of characterization methods for CMs are required.

DEEP: KMTNet DEep Ecliptic Patrol

  • 문홍규;최영준;김명진
    • 천문학회보
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    • 제36권2호
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    • pp.122.2-122.2
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    • 2011
  • For more than a decade, NEA (Near-Earth Asteroid) survey teams equipped with 1 meter-class telescopes discovered thousands of NEAs in the northern sky. As of August 2011, some 8,200 NEAs have been cataloged, yet only five percent of them has been investigated for their physical and chemical properties. In order to improve current situation, we propose a deep ecliptic survey utilizing KMTNet, for detection and characterization of NEAs in the southern sky. Thanks to the wide-field capability (four square degrees) of the telescopes, we will be able to considerably expand the search volume carrying out precision photometry down to 21.5th magnitude. We plan to focus our survey on opposition and two "sweet spots" in the ecliptic belt. Since SDSS colors characterize mineralogical properties of NEAs, g', r', i', z' filters will be employed. Based on the round-the-clock observation, we will study their rotational properties; for multiple systems, mass, density and other physical parameters can be obtained. We plan to maintain a dedicated database of the physical and mineralogical properties of NEAs. With this archive, it is expected that our understanding on the population will see a drastic change. We also plan to participate in the GAIA Follow-Up Network for ground based observation of the Solar System Objects (GAIA-FUN-SSO). The follow- up astrometry will be performed upon alerts issued by the GAIA-FUN-SSO Central Node in France.

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