• 제목/요약/키워드: diatomite

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극저농도 NDMA(N-nitrosodimethylamine) 물리적/생물학적 처리 효율 비교 평가 (Evaluation and Comparative Physical/Biological Removal Performance for Extremely Low-Concentration NDMA(N-nitrosodimethylamine))

  • 박세용;김희주;김문일
    • 한국지반환경공학회 논문집
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    • 제12권2호
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    • pp.55-61
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    • 2011
  • NDMA(N-Nitrosodimethylamine)는 극저농도(10ng/L)에서도 암을 일으킬 수 있는 물질로 알려져 있지만, 기존의 NDMA 제거율 평가 연구는 고농도의 NDMA를 대상으로 한 것이 대부분이었다. 따라서 극저농도의 NDMA 제거효율 평가가 필요하며 그 기초연구로써 호기성/혐기성 조건에서의 분말활성탄, GS(Granular Sludge), MF(Microfiltration), UF(Ultrafiltration)를 이용한 제거효율과 Silica gel(MCM-41, Diatomite, Spherical silica gel)을 이용한 제거효율을 평가하였다. 그 결과 혐기성 조건에서 GS, PAC를 접촉한 후 UF membrane을 이용한 고액분리가 65%의 제거율로 가장 높았으며, Silica gel(MCM-41)이 6%의 제거율로 가장 낮았다. 본 연구는 극저농도의 NDMA 제거의 기초 연구로서 향후 관련 연구의 기초자료로써 활용을 기대한다.

수열 합성에 의해 제조된 다공성 Wollastonite Ceramics의 특성 (Characteristics of Porous Wollastonite Ceramics Fabricated by Hydrothermal Synthesis)

  • 김병훈;나용한
    • 한국세라믹학회지
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    • 제32권8호
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    • pp.893-900
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    • 1995
  • The porous wollastonite ceramics were fabricated after firing calcium silicates, obtained using natural resources and by-products of power plants by hydrothermal synthesis, without organic fibers or asbestos for reinforcement agent. A specimen from diatomite as a SiO2 staring raw material had the highest strength owing to normal grain growth and good densification from homogeneous sperhcial C-S-H hydrates. A specimen from SiO2 sol as a SiO2 starting raw material showed tobermolite, but fly ash and mixed system did xonotlite after hydrothermal synthesis. The specimen from fly ash showed the lowest firing shirikage and strength changes in the firing range from 50$0^{\circ}C$ to 120$0^{\circ}C$. The other phases in all specimens changed to wollastonite phase after firing at 100$0^{\circ}C$. Also the average pore size was distributed from 0.2${\mu}{\textrm}{m}$ to 2${\mu}{\textrm}{m}$.

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무기소재 및 생물환경 소재로서의 규조류 활용 연구 동향 (Recent Researches for Diatom as Inorganic and Bioenvironmental Materials)

  • 장의경;신현경;백승필
    • KSBB Journal
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    • 제29권1호
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    • pp.9-21
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    • 2014
  • One of the most abundant microalgaes, diatom is characterized by its unique cell wall structures composed of nano-patterned silica. Due to its highly ordered porosity, these silica frustules, which are found as sediments called diatomite, were used as a cheap adsorption material for water purification. Recently, new emerging nanotechnology compels many researchers to have interest in such diatom's unique properties (eg, nano-scale mesoporosity, photo luminescence, light transparency, etc.) as biogenic inorganic materials as well as the biomass resource (conventional usage of microalgae). In this review, we will focus on the current knowledge about the diatoms research and the possibility of its applications.

베어링용 흑연재 Bushing 개발 (Development of Graphite Bushing for Bearing)

  • 김경자;조광연;정윤중;임연수
    • 한국세라믹학회지
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    • 제34권8호
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    • pp.797-802
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    • 1997
  • The use of carbon materials in mechanical components such as bearings, seals, and bushings that do not require lubricants is increasing rapidly. This paper reports on establishing the optimal condition for resin-bonded carbon materials. We fixed the content ratio of materials, which include graphite powder and diatomite as a lubricant modifier and a friction modifier, respectably, with resin used as a bonding material. We then produced bushings using hot-pressing within the temperature range of resin curing. The properties of bushing, the friction coefficient, wear rate and the mechanical strengths are discussed in relation to the content of respective materials, with correlation of friction coefficient and sliding distance. Finally, we examined the friction coefficient changes according to the applied load on bushing and the friction coefficient changes according to contact speed of bushing.

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단열성능 향상 콘크리트의 현장 적용성 평가에 관한 연구 (Study on the Field Application of Insulation Performance Improvement Concrete)

  • 강성혁;김정호;추경남;박영신
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2014년도 추계 학술논문 발표대회
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    • pp.17-18
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    • 2014
  • Recently, climate change have increased consumption of building heating and cooling energy. Therefore, various actions to reduce greenhouse gas and energy consumption have been prepared by world developed countries. The energy consumption by buildings approximately reaches 25% of total korea energy consumption. The greatest part in the buildings of the energy consumption is building facade. Especially the outer covering of the building has been made of concrete more than 70%. But a few research projects on concrete comprising more than 70% of outsider of buildings has been tried. This research is structural insulation concrete what improved insulation performance using Micro Form Admixture and Calcined Diatomite Powder and Lightweight Aggregate.

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GC/FPD를 利用한 ${\beta}$-락탐系 抗生物質의 分析(II) (Determination of ${\beta}$-Lactam Antibiotics by Gas-Chromatography with Flame Photometric Detector (II))

  • 박만기;조영현;양정선;박정일
    • 약학회지
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    • 제28권4호
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    • pp.243-248
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    • 1984
  • For gas chromatographic determination with the sulfur-specific flame photometric detector, nine ${\beta}$-lactam antibiotics without ${\alpha}$-amino group were esterified with borontrifluoride-methanol complex and then N-benzoylated with benzoyl chloride. The gas chromatographic separation of these products was successfully carried out on various silicon polymers (OV-1, OV-101, OV-17, OV-225, and QF-1) coated on the acid washed, silanized diatomite. The structure of the esterified and N-benzoylated product was confirmed by mass spectromer.

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실리카겔을 활용한 흡착 경화체의 열전도율 특성 (Thermal Conductivity Properties of Adsorption Matrix According to Silica Gel)

  • 권오한;임현웅;이동훈;이상수
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2017년도 추계 학술논문 발표대회
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    • pp.109-110
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    • 2017
  • In recent years, it has been urgently required to develop and study a product that adsorbs and reduces lardon gas due to the risk of lardon gas in Korea. Therefore, this study develops a board for adsorbing lardon gas into the inside and outside of the room. The thermal conductivity was measured in order to carry out an adiabatic test for satisfying the following conditions. Experimental level and factors were substituted with silica gel. In addition, silica gel was used by dry mixing and prewetting, and 10, 20, and 30% of cement was substituted for each. As a result of the test, the thermal conductivity decreased to 0.45 W/mK with increasing the amount of replacement, and reached a similar level when compared with diatomite.

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단열성능향상 재료를 사용한 콘크리트의 열적 특성에 관한 연구 (Study on the Thermal Characteristics of Concrete Using Insulation Performance Improve Material)

  • 박영신;김정호;강연우;염광수;전현규
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2013년도 춘계 학술논문 발표대회
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    • pp.227-228
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    • 2013
  • Recently, it is certain that the increase of heating and cooling energy consumption by radical change in climate condition has caused serious problems related to environmental and energy concerns associated with increase of fossil fuel usage and carbon dioxide production as well as global warming. So, various actions to reduce greenhouse gas exhaustion and energy consumption have been prepared by world developed countries. The energy consumption by buildings approximately reaches 25% of total korea energy consumption. The greatest part in the buildings of the energy consumption is building facade. but a few research projects on concrete comprising more than 70% of outsider of buildings has been tried. This research structural insulation concrete what improved insulation performance using insulation performance improve material.

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쓰레기 소각재 사용 콘크리트의 품질특성에 대한 실험적 연구 (An Experimental Study on the Quality of Concrete with Municipal Solid Waste Incineration Ash)

  • 김재우;최재진;문대중
    • 한국건설순환자원학회논문집
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    • 제2권4호
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    • pp.335-344
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    • 2014
  • 쓰레기 소각재(소각재)를 콘크리트용 재료로 재활용하기 위하여 소각재의 품질특성에 대하여 분석하였으며, 소각재를 사용한 콘크리트의 유동특성 및 강도특성에 대하여 검토하였다. 소각재의 화학성분은 CaO 성분이 50%이상을 차지하고 있었으며, 소각재의 누적입도분포 50%의 평균입경은 $25{\mu}m$ 정도를 나타내었다. 소각재 IA1의 입자형상은 미세입자가 뭉쳐져 구형상을 나타내고 있으며, 소각재 IA2의 입자형상은 미세입자가 판상 형상으로 겹쳐져 있는 구조로 제조공정에 따라 다르게 나타났다. 소각재를 사용하므로써 콘크리트의 품질특성에도 크게 영향을 미쳤으며, 소각재 IA2를 사용한 경우 슬럼프가 증가하고 고성능감 수제 사용량이 감소하였으나, 압축강도 발현은 저하하였다. 소각재 IA2와 규조분말을 병용하여 혼합하므로써 목표슬럼프를 얻기 위한 고성능감수제의 사용량은 증가하였으나, 재령 28일 압축강도는 향상되는 효과가 있었다. 또한, 압축강도와 인장강도와의 비는 CEB-FIP 코드의 85%~105% 범위내에 있었다.

Penicillium sp. GL-101의 액침배양중 Mycelial Pellet 크기에 영향을 주는 배양조건 및 첨가물 (Culture Conditions and Additives Affecting to the Mycelial Pellet Size of Penicillium sp. GL-101 in the Submerged Culture)

  • 이동규;하철규;이태근;강선철
    • Applied Biological Chemistry
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    • 제42권3호
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    • pp.188-192
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    • 1999
  • 유리인산 생성균 Penicillium sp. GL-101의 액침배양증 mycelial pellet 형성을 억제하기 위하여 배양조건(배지 종류, 초기접종량)과 배지 첨가물(점토광물, 계면활성제, PEG 200)의 종류에 따라 pellet 형성에 미치는 영향을 조사하였다. 그결과 이 균주는 배지종류를 달리하여 배양했을 때 YPD > SBD > PDB 순으로 pellet 크기가 감소하였다. 또한 이 균주는 $1{\times}10^3{\sim}1{\times}10^6$ conidia/ml 범위의 초기접종농도에서는 농도가 높을수록 pellet의 크기는 감소하였으며, $1{\times}10^7{\sim}1{\times}10^8$ conidia/ml 범위의 농도에서는 무정형의 불규칙적인 pellet을 형성하였다. 점토광물인 zeolite와 diatomite를 각각 1.0% 농도로 첨가하였을 경우에는 pellet이 3/4과 1/2로 감소하였으나, bentonite를 1.0% 첨가하였을 경우에는 오히려 pellet 크기가 2.5배 증가하였다. 계면활성제 역시 이 균주의 mycelial pellet 형성에 영향을 미쳤다. 즉 Triton X-100과 Tween 80을 각각 1.0%로 첨가하였을 경우 pellet 크기가 1/10과 1/4로 감소하였고, SDS를 첨가할 경우에는 이 균의 성장이 완전히 저해되었다. 그리고 PEG 200을 1.0% 농도로 첨가했을 경우에 직경 $0.2{\pm}0.1\;mm$의 pellet이 형성되었으며, 이는 대조군에 비하여 1/25의 크기로 이 실험에 사용된 배지 첨가물 중에서 가장 효과적으로 pellet 형성을 억제하였다.

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