• 제목/요약/키워드: mud

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머드플랩이 개선된 KTX차량의 궤도구간별 실내소음 특성에 관한 연구 (A Study on the Interior Noise Characteristics of KTX with Improved Mud Flap for Various Track Conditions)

  • 김진호;김우리;박대근
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2006년도 추계학술대회 논문집
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    • pp.345-349
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    • 2006
  • There has been an increasing demand for the mitigation of noise and vibration caused by KTX. One of considered noise reduction methods which is to enlarge mud-flap in gangway was selected and the replacement of all KTX mud-flaps by improved mud-flaps was completed recently. To investigate the noise characteristics of KTX with improved mud-flap, the measurement was performed. Based on the measurement results, the assessment of noise level, noise characteristics by speed and pure tone analysis for various track conditions was executed. It is shown that the use of improved mud-flap is effective to reduce the interior noise of KTX.

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지표레이다(GPR) 탐사에 의한 하상퇴적물 조사

  • 장현삼;정성태
    • 지구물리
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    • 제5권1호
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    • pp.51-62
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    • 2002
  • 지표레이다(GPR)를 이용하여 하상 퇴적물 조사를 수행하였다. 조사지역은 수심이 약 2.5 m 정도로 얕고, 물이 흐르지 않는 호수이며, 조사대상인 뻘(mud)층의 두께가 얇아 GPR이 매우 효율적인 탐사방법이다. 조사결과 수심하부 층서구조, 즉 mud층, 모래층, 자갈 및 기반암의 구조를 확실하게 파악할 수 있었다. 특히 mud층의 분포 및 총 퇴적량은 향후 이 지역에서의 준설을 위한 기초자료로 매우 중요하게 사용될 수 있을 것이다.

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질산 중화 레드머드를 첨가한 시멘트 페이스트의 초기강도 특성 (Initial Strength Characteristics of Cement Paste Added with Nitric Acid Neutralized Red Mud)

  • 강혜주;강석표
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2021년도 봄 학술논문 발표대회
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    • pp.70-71
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    • 2021
  • An increasing amount of red mud (RM) is being generated globally with the growth in alumi-num production. To avoid the RM becoming a pollutant, methods for effectively recycling RM at a low cost are being investigated. This study proposes a method for recycling RM as a construc-tion material. The cement paste with neutralized liquefied red mud had higher compressive strength than that of plain cement paste and cement paste with liquefied red mud without neutralization at 1 d of aging; this indicates that nitric acid neu-tralization increases the early-age strength.

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서해안 갯벌 쏙(Upogebia major) 서식지와 비 서식지의 퇴적환경 특성 (Comparison of Sedimentary Environmental Characteristic of Tidal Flats on the West Coast of Korea Depending on the Habitation of Mud Shrimp Upogebia major)

  • 전승렬;홍석진;최용현;조윤식;송재희
    • 한국수산과학회지
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    • 제52권6호
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    • pp.656-665
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    • 2019
  • Environmental monitoring was conducted to identify the characteristics and patterns of sedimentary environments of tidal flats in 12 areas on the west coast of Korea. The habitat of the mud shrimp Upogebia major contained higher organic and mud contents compared to the habitat of the manila clam Ruditapes philippinarum. In particular, the mud content increased from 84.38% to 89.18% in the Seongam-4 area, where the mud shrimp and manila clam coexist, and the mean grain size exhibited a finer particle size, from 5.48 Φ to 5.80 Φ. In the mud shrimp habitat, the sediment mud content was > 60% and the mean grain size was > 5 Φ. Additionally, the mud shrimp only inhabited open coast tidal flat areas. The management of shellfish aquaculture farms by physical methods should be continued based on comparison of the sedimentary environments in the Boryeong and Seongam areas in response to the damage to the mud shrimp habitat.

축제식(築堤式) 폐양식장을 활용한 고창 갯벌 복원계획 수립 (A Establishment of Mud Flat Restoration Plan in Gochang Using Abandoned Embanked Farms)

  • 최희선;김효창
    • 한국환경복원기술학회지
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    • 제13권2호
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    • pp.124-137
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    • 2010
  • This study was started with the objective of restoring abandoned embanked farms, which are recently increasing, to mud flat by putting in least amount of energy in the aspect of environmental restoration. For the direction and establishment of the proposal for the restoration of mud flat using embanked farms, a case of Maipo Wetland in Hongkong was analyzed, and a proposal was prepared considering the condition of mud flat in Gochang. The restoration of mud flat in Gochang is intended to create various wetland ecological spaces as well as to provide opportunities for experience, education, recreation, and tourism. Effort was made to development an environment closest to the local ecological environment considering the shape and topographical condition of existing abandoned farms. For construction of the habitat, a target species was chosen and the plan for selection, planting, and management of species of trees suitable for the target species was established. In addition, the water level will be controlled by water gates to conform to the resting, spawning, breeding, and migration period considering the behavioral pattern of waders, the target species. The research on the restoration of mud flat in Korea is in incipient stage and this study provided an opportunity to review the possibility of restoration of abandoned embanked farms to mud flat. For the success of mud flat restoration from a long-term perspective, development of acclimating design infrastructure, technology improvement for mud flat restoration, and basis of partnership for the maintenance should be prepared in a systematical way.

레드머드 대체율에 따른 폴리머 혼입 알칼리활성화 슬래그-레드머드 시멘트모르타르의 강도 및 기공특성 (Strength and Pore Characteristics of Alkali-activated Slag-Red Mud Cement Mortar used Polymer According to Red Mud Content)

  • 권성준;강석표
    • 한국구조물진단유지관리공학회 논문집
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    • 제20권2호
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    • pp.26-33
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    • 2016
  • 알칼리활성화 슬래그-레드머드 시멘트는 알칼리활성화 시멘트 연구의 일환으로서 시멘트 조성에서 알칼리자극제, 고로슬래그와 레드머드로 구성되어져 있으며, 포틀랜트 시멘트를 사용하지 않는 클링커 프리 시멘트(Clinker Free Cement)를 의미한다. 본 논문에서는 포틀랜트 시멘트를 전혀 사용하지 않고 고분자 유기화합물인 재유화형 분말 폴리머를 혼입한 알칼리활성화 슬래그 시멘트에 레드머드의 대체율을 달리하여 강도특성, 기공특성 등을 기존 포틀랜트 시멘트와 비교 평가하였다. 그 결과 알칼리활성화 시멘트에 레드머드를 대체할 경우 C-S-H 광물상과 에트린가이트가 주요 수화생성물로 포틀랜트 시멘트와 비교하여 조직이 치밀하고 대체율 10%까지는 압축강도 및 휨강도가 증가하였다.

Red mud와 제지회를 혼합한 CLSM의 적정 혼합비 산정 (The Estimation of Optimal Mixing Ratio of CLSM Mixed with Red Mud and Paper Sludge Ash)

  • 노성오;김태연;이봉직
    • 한국지반환경공학회 논문집
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    • 제23권4호
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    • pp.21-27
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    • 2022
  • 최근 GGBS 및 Fly ash 등과 같은 산업부산물과 알칼리 자극제를 활용한 알칼리 활성화 시멘트에 대한 연구가 활발히 진행되고 있다. 알칼리 활성화 시멘트는 산업부산물에 알칼리 자극제를 혼합함으로 시멘트를 사용하지 않고 강도를 발휘하는 결합재의 일종으로 대표적인 탄소저감 기술이나, 알칼리 활성화를 위해 사용되는 알칼리 자극제는 고가이며 강알칼리성으로 인한 위험성으로 현장적용에 여러 어려움이 있다. 이에 본 연구에서는 알칼리 자극제의 대체재로 Red mud의 활용방안을 모색하고자 Red mud와 제지회를 결합재로 활용한 CLSM의 유동특성, 강도특성 등의 공학적 특성과 토양오염 발생가능성을 평가하였으며, Red mud와 제지회를 혼합한 CLSM의 적정 혼합비를 제시하였다.

마우스에서 황토국화 추출물의 급성독성 연구 (Acute Toxicity Study on Mud chrysanthemum Indicum in Mice)

  • 마진열;박화용;최한;지옥표;이재훈
    • 대한본초학회지
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    • 제23권2호
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    • pp.81-85
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    • 2008
  • Objectives : The aim of this study is to collect data for toxicity and safety of Mud chrysanthemum indicum. Methods : In this study, we investigated the acute toxicity for buthanol-extracted Mud schrysanthemum indicum, 25 male and 25 female mice were observed for 14days after one day oral administration of Mud chrysanthemum indicum at the respective doses of 0(control group), 1024, 1280, 1600 and 2000mg/kg. Results : We observed survival rates, general toxicity, change of body weight and autopsy. No abnormality was found for all cases. Conclusions : The data confirmed that Mud chrysanthemum indicum is free from, the toxicity and safety problems. Compared with the control group, we could not find any toxic alteration in all treated groups (1024, 1280, 1600 and 2000mg/kg), In conclusion, LD50 of Mud chrysanthemum indicum was over 2000 mg/kg and it is very safe to mice.

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전통주택 흙벽을 대신할 수 있는 건식벽체 성능평가에 관한 연구 (A Study of Dry-Wall Performance Evaluation - An Alternative to Korean Traditional Mud Walling -)

  • 황용운
    • 한국주거학회논문집
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    • 제22권6호
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    • pp.61-69
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    • 2011
  • Korea's traditional house type, the Hanok, has been the essence of Korean domestic culture for hundreds of years. However, Hanok, have begun to disappear as result of urbanization. Because mud walls are crude and weak in water walls are also easily broken by impact. There are further problems in that construction cost is expensive and takes more time than modern house construction, and that the maintenance of Hanok is more difficult than people sometimes predict. Despite much interest in Hanok construction, there is a lack of in younger generation. Thus seeking new ways of maintaining Korea's traditional housing culture and extending Korean traditional houses is important. This study proposes directions for creating new residential environments for the future generation of Korea. A Dry-wall alternative to the Korean traditional mud wall is particularly needed. Dry-walling, made by sustainable materials such as mud board and wood, can strengthen the advantages and make up for the weaknesses of the Korea traditional mud wall. In this study, both wall types underwent various evaluations in terms of their performance in insulation testing, freezing and thawing testing, impacting testing and weight measuring (the size of material in this experiment was $69cm{\times}105cm$). On all of these tests, findings revealed that the dry-wall alternative performed better than traditional mud wall.

순환골재를 사용한 알칼리활성화 슬래그-레드머드 흙포장재의 특성 (Properties of Alkali-activated Slag-Red Mud Soil Pavement Using Recycled Aggregate)

  • 강석표
    • 한국건설순환자원학회논문집
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    • 제4권3호
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    • pp.276-283
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    • 2016
  • 레드머드는 보오크사이트 원광석에서 생산되는 알루미나의 선광과정에서 발생되는 무기질 부산물이다. 인 레드머드를 활용하고자 하는 연구가 국내에서 이루어지고 있다. 강알카리성의 레드머드를 건설산업용 촉진제로서 활용하고자 하는 연구로서 알칼리활성화 슬래그-레드머드 시멘트가 국내외적으로 발표되고 있다. 본 논문은 순환골재 대체율에 따른 알칼리활성화 슬래그-레드머드 건식 흙포장재의 최적함수율, 압축강도, 흡수율, 백화발생 특성에 대하여 비교 검토하였다. 그 결과 순환골재 대체율이 증가할수록 알칼리활성화 슬래그-레드머드 흙포장재의 최적 함수비, 물흡수계수, 백화면적은 증가하고 압축강도는 감소하였다.