• Title/Summary/Keyword: Harmful material

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Evaluation of Hydration Reactivity of Recycled Cement for the Utilization of Radioactive Waste Solidifying Materials (방사성 폐기물 고화재 활용을 위한 재생시멘트의 수화반응성 평가)

  • Choi, Yu-Jin;Kim, Ji-Hyun;Chung, Chul-Woo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2022.11a
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    • pp.167-168
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    • 2022
  • Recently, starting with the permanent suspension of Gori 1 in Korea, the importance of the disposal of concrete structures in nuclear power plants has emerged, and environmental and safety are required to be proved accordingly. Safe radioactive waste disposal technology that immobilizes harmful radioactive elements, which are by-products of nuclear power, inside a solid matrix and recycling measures are needed to secure an efficient waste disposal space. This study was conducted to confirm whether recycled cement generated in the process of radioactive concrete treatment can be used as a solidifying material for radioactive waste treatment. In order to simulate the concrete exposed to radiation, aqueous solutions of Di-water, CsCl 1M, and CoCl2 1M were used as blending water at W/B 0.5. Tricalcium phosphate and Prussian blue were substituted with 5 wt.% based on the weight of recycled cement as a binder to improve solidification performance, and their hydration characteristic was analyzed.

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Physical Propertise of Non-Cement Matrix with Red Mud (레드머드를 혼입한 무시멘트 경화체의 물리적 특성)

  • Kwon, Hyeong-Soon;Lee, Sang-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2023.05a
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    • pp.93-94
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    • 2023
  • Through the industrial revolution that began in the 18th century, the amount of carbon dioxide in the atmosphere increased rapidly as humans used fossil energy such as coal and oil as fuel for steam engines and factory machines. The amount of carbon dioxide emitted while producing cement, the main material of concrete used in construction, is large enough to account for 5-8% of the world's carbon dioxide emissions. In this study, Non cement-based matrix were used to reduce carbon dioxide emissions from cement production. Red mud is an industrial by-product generated in the manufacturing process of aluminum hydroxide using bauxite, and more than 120 million tons are produced worldwide. In addition, red mud is a porous material that can be physically adsorbed, and causes a photocatalytic reaction of TiO2 to remove harmful substances such as nitrogen oxide formaldehyde in the air and chemically adsorbs ammonia and hydrogen sulfide. Therefore, this study aims to examine the physical properties of the matrix by mixing red mud, an industrial by-product with good adsorption performance, into the Non cement-based matrix.

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Development of an Earthquake-Resistant Model for a High-Level Waste Disposal Canister (고준위 폐기물 처분용기 내진 해석 모델 개발)

  • Choi, Young-Chul;Yoon, Chan-Hoon;Kim, Hyun-Ah;Choi, Heui-Joo
    • Tunnel and Underground Space
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    • v.24 no.4
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    • pp.316-324
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    • 2014
  • In the underground 500 m depth, the high level radioactive waste disposal system is made by boring the tunnel in the base rock and putting the high level waste disposal canister that is the surrounding form with the buffer material. According to the many statistics, it is the tendency that the earthquake increases in the Korean peninsula every year. In case that the earthquake is generated, the disposal canister in the rock mass can be broken due to the shearing force in the underground. Furthermore, a major environmental problems can be caused by the radioactive harmful substances. In this study, the earthquake-proof type buffer material was developed with the protection method safely on the earthquake. The main parameter having an effect on the earthquake-resistant performance was analyzed and the earthquake-proof type buffer material was designed. The shear analysis model was developed and the performance of the earthquake-proof type buffer material was evaluated by using ABAQUS.

Study on the Effect of Corrosion Gas and Acidic Falling Materials for Conservational Wax on the Copper based Sculpture (동(銅)이 주종을 이루는 조형물 보존용 왁스의 산성강하물 및 부식 가스에서의 영향성 연구)

  • Oh, Seung-Jun;Wi, Koang-Chul
    • Journal of Conservation Science
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    • v.26 no.4
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    • pp.437-443
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    • 2010
  • The influence of noxious corrosive gas, which is the product of fossil fuel, and the acidic descent material, which becomes the reason for such reaction, on wax which protects the cultural assets, and the habitat factor were researched. It could be viewed that corrosion occurred rapidly due to the acidic descent material, which have the long staying on the material, rather than harmful corrosive gas. Also, it could be figured out that such corrosion began from whitening phenomenon of coated wax. As the acidity increased, more whitening phenomenon occurred, and eventually, it could be found out that whitening effect began due to the acidic descent material, corrosive gas and various 0.1 M acid solution, which lead to the exposure of internal metal, and corrosion occurred. The wax with the greatest resistance to the acidity due to its least changing aspect seemed to be Renaissance wax, except sulfuric acid.

An Experimental Study on the Fundamental Properties of Zeolite Concrete (제올라이트 콘크리트의 기초 물성에 관한 실험적 연구)

  • Jo, Byung Wan;Choi, Ji Sun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.16 no.1
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    • pp.1-8
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    • 2012
  • Since the cement industry is expected to face serious setbacks in the near future associated with environmental concerns. With the advent of new technologies and increased public awareness about global environmental issues, the cement industry is actively seeking to adopt new technologies as part of an effort to diversity its resources. This study is designed to assess the fundamental properties of zeolite cement concrete which consists mainly of natural zeolite, which is known for removal of and harmful gas, ion exchange capacity removing cation contaminant including heavy metals and ammonia, absorptive capacity and molecular sieving effect together with excellent insulation capacity as a porous material, and recently draws much attention for its possibility as an alternative material to cement. The study was conducted to show the compressive strength of concrete, slump, bleeding and air volume according to the changes of natural zeolite and alkali activator(NaOH). As a result of measuring the compressive strength of natural zeolite concrete, it was almost 40MPa and displayed similar to general concrete in the tests of slump, bleeding and air volume, with which it was considered that it may be used as a future high performance, high performance construction material.

Inhibition Effect of the Harmful Food-Born Microorganisms on Germination Condition of Acorn Pollen (도토리 화분의 발아 조건에 따른 식품유해균 억제효과)

  • Choi, Jun-Hyug;Yim, Ga-Young;Jang, Se-Young;Jeong, Yong-Jin
    • Food Science and Preservation
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    • v.14 no.1
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    • pp.87-93
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    • 2007
  • This study investigated the antimicrobial effect of germinated acorn pollen solution on harmful food-borne microorganisms. The antimicrobial activity when 8% (w/v) acorn pollen in 10% (w/v) sugar solution was extracted at $30^{\circ}C$ for 4 days. The minimal inhibitory concentration of this germinated acorn pollen solution was $40\;{\mu}L/mL$ for Gram-positive bacteria and $30\;{\mu}L/mL$ for Gram-negative bacteria. Acetic and lactic acids were present at high levels in germinated acom pollen solution. As pollen germination releases heat, the antimicrobial activities are heat-stable. The activities are tolerant of low pH. In summary, acorn pollen germination solution showed active antibiosis and should be developed as a natural preservative material.

Glycine max Merr enhances the viability and adhesion ability of Lactobacillus buchneri in gastrointestinal condition in vitro.

  • Seo, Jae-Bin;Park, Bog-Im;Myung, Hyun;Sim, Hyeon-Jae;Lee, Hoon-Yeon;Kim, Seong-Oh;Song, Kyoung-Ha;Lee, So-Jin;Cho, Jung Hee;Jeon, Yong-Deok;Jin, Jong-Sik
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2018.10a
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    • pp.127-127
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    • 2018
  • Probiotics are microorganisms that have beneficial effects on the health of the host. The health promoting effect by probiotics influences suppressing harmful bacteria, prevention of constipation, blood cholesterol reduction and regulation of blood pressure. Prebiotics are used to promote the growth or activity of microorganisms. Synbiotics, which are a mixture of probiotics and prebiotics, synergize in the intestines by complementing each other. Synbiotics not only improves the viability of the probiotics while passing through the gastrointestinal tract, maintain intestinal homeostasis, but also regulate balance of harmful and useful bacterial growth. Glycine max Merr (GMM) has been widely used in Asian countries to treat cancer, obesity, oxidative stress and imbalanced immune diseases. In addition, it has been reported that dietary fiber-rich grains promote bowel movements and prevent constipation. In this study, we investigated the viability of LactobacillIus buchneri (L.buchneri) strains, known as lactic acid bacteria under conditions of gastric fluid and intestinal fluid to determine the suitability of L.buchneri as probiotics. The adhesion ability of L.buchneri to caco-2 cells was also confirmed. The present studies showed that GMM extract promoted the growth and activity of L.buchneri strains as prebiotics. Also, this results suggested that the mixture of L.buchneri and GMM extract can helps maintain intestinal health and healthy body as synbiotics and health functional food material.

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A Study for Development the Air Cleaner Using Air Ionizing Phenomena and Optical Catalizer (공기전리 현상과 광촉매를 이용한 공기정화 장치 개발에 관한 연구)

  • Shim, Chung-Han;Lee, Won-Dae;Lee, Dong-Hoon;Jung, Yong-Chul
    • Journal of the Korean Society of Safety
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    • v.21 no.5 s.77
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    • pp.28-33
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    • 2006
  • The rapidly advanced industrial society takes advantage of high-technology, but it also suffered from the side effects such as various diseases by contamination. Of these problems, air pollution is considered as the most important problem nowadays. Air contamination is not only limited outdoors, but it also causes more serious effect in our indoor air environment. Depending on the notion that indoor air effects physical health seriously, the needs of the air cleaner is more earnest. Therefore, the main purpose of this study is to develop the air cleaner to meet the standard and get rid of poisonous and harmful material from the atmosphere by using a Corona Discharge. According to the purpose of this study, We set the negative ion generator, the UV, $TiO_{2}$ optical catalyzer, the electrical dust collector and the air filter in series order. It emits a lot of negative ions. We use these ions to purify harmful factors and contaminated materials. We collect the dust using static power that comes from the discharge of corona. At the same time, we try to develop the air cleaner to keep the air quality to meet the standard and kill the various viruses using UV LED and $TiO_{2}$ optical catalyzer. In this study, we use the UV LED that is smaller and efficient than a existing UV lamp. What is more, the UV LED has a features that a stabilizer occupying much space is not needed any more.

Study on Traditional Folk Wine of Korea -In the Central Region of Korea-Seoul, Kyonnggi-do, Chungchung-do- (한국의 민속주에 관한 고찰(I) -서울.경기도.강원도.충청도 지방을 중심으로-)

  • Yoon, Sook-Ja;Jang, Myung-Sook
    • Journal of the Korean Society of Food Culture
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    • v.9 no.4
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    • pp.341-353
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    • 1994
  • This study delves into the general characteristics of spirits brewed in the Central Region of Korea-Seoul, Kyonnggi-do, Chungchung-do-paying particular attention to their varieties and fermenting methods and also comparing similarities and differences of their features. It is found first of all that there are a wide range of variety in the kinds of liquors. Among the 21 spirits investigated, not a single one resembles any one of the remaining in terms of the raw material, and the brewing method and process. Secondly, all of them use locally produced grains and can be classifiable as belonging to the common category of yakju (clean spirit) with fragrant elements added for the purpose of enhancing health or decreasing any harmful effects after drink. Thirdly, these traditional folk wines are characterized by the addition of secondarily fermented spirits. The more secondarily fermented spirit a wine has, the more fragrant and palatable it becomes and also the less harmful. Fourthly, all the spirits of this region are fermented by using yeast kodupap (steamed rice). The brewing temperature is usually around $15{\sim}20^{\circ}C$ for $5{\sim}8$ days or $3{\sim}4$ days for the majority of the cases. Fifthly, purifying is done with the yongsoo (strainer), the sieve, traditional Korean paper, etc. As such, we can say that all the brewers endeavor to maintain Korean traditional methods of wine making.

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Host-Parasite System in a Red Tide Dinoflagellate Prorocentrum minimum: (1) Life Cycle Stages of the Parasitic Dinoflagellate Amoebophrya sp. (적조생물 Prorocentrum minimum의 숙주-기생자 배양체: (1) 기생성 와편모류 Amoebophrya sp.의 생활사 단계)

  • 김영길;박명길;이원호
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.7 no.4
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    • pp.2221-2221
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    • 2002
  • The first laboratory culture of host-parasite system of Prorocentrum minimum- Amoebophrya sp. was established by single cell isolation method. Here, we report the life cycle stages of the parasitic dinoflagellate. Amoebophrya sp. of the red tide dinoflagellate P. minimum as observed by light and epifluorescence microscopy. Infections developed inside the nucleus of P. minimum. The trophont developed to occupy almost all the intracellular space of the host at its late stage. The fully developed trophont finally ruptured through the host cell. “Vermiform stage”, the free-swimming extracellular lift cycle stage is followed by another stage for the sudden release of many individual dinospores. Our laboratory strain of the host-parasite system for P. minimum, a causative species fur the huge red tides in spring and summer in Korean coastal waters, could be a useful living material for the in situ biological control of harmful algal blooms.