• 한국물환경학회지
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• 제28권2호
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• pp.277-284
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• 2012

This study developed a new ceramics in which natural zeolite was mixed and calcined with industrial by-product such as converter slag, red mud, and fly ash and evaluated the feasibility of the ceramics for removal of heavy metals in acid wastewater. The removal rate of heavy metal by ceramics increased in the order of ZS (zeolite and slag) > ZR (zeolite and red mud) > ZF (zeolite and fly ash) ceramics. The alkalinity increment and coherence of ceramics were increased in the order of ZS > ZR > ZF ceramics. The mixing ratio of natural zeolite to industrial by-product for maximum removal efficiency of heavy metal was 1:1 for ZS ceramics and 1:3 for ZR and ZF ceramics. The order of removal efficiency of heavy metal was observed to be ZS > ZR > ZF ceramics under the mixing ratio of 1:1 for ZS ceramics and 1:3 for ZR and ZF ceramics. The removal efficiency of heavy metal by ZS ceramics with 1:1 mixing ratio was Al 100%, Cd 54.6%, Cr 99.9%, Cu 98.7%, Fe 99.9%, Mn 42.2%, Ni 59.9%, Pb 99.8%, Zn 87.6%, respectively. In addition, the removal capacity of heavy metal by ZS ceramics was observed to be Al 2.01 mM/g, Cd 0.27 mM/g, Cr 1.02 mM/g, Cu 0.83 mM/g, Fe 0.95 mM/g, Mn 0.41 mM/g, Ni 0.55 mM/g, Pb 0.25 mM/g, Zn 0.70 mM/g, respectively. The comparative evaluation in the light of removal capacity, alkalinity increment, and coherence of ceramics showed the ZS ceramics had higher feasibility as a media than others for removal of heavy metals in acid wastewater.

• 한국항해항만학회지
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• 제27권1호
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• pp.75-80
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• 2003

천연세라믹, 옻칠, 그리고 고무의 전파흡수능을 조사하였다. 천연세라믹은 2.5GHz~4.5GHz의 주파수 범위에서 2.5dB이상의 전파흡수능을 나타내었으며 옻칠의 전파흡수능이 기존에 전파흡수체의 지지재로 이용되는 고무에 비해 우수한 전파흡수능을 갖고 있음을 확인하였다. 페라이트에 옻칠을 지지재로 이용한 전파흡수체에 대하여 시뮬레이션 한 결과 0.5GHz~10GHz의 주파수 범위에서 16dB 이상의 우수한 전파흡수능을 나타내었다. 따라서 기종에 지지재로 이용하던 고무대신 본 연구에서 새롭게 제안하는 옻칠을 전파흡수체의 지지재로 이용하는 것이 광대역에서 우수한 전파흡수체를 얻을 수 있을 것으로 예상된다.

• Journal of Biosystems Engineering
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• 제39권3호
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• pp.227-234
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• 2014

Purpose: The aim of this research was to develop and evaluate natural hydroxyapatite (HA) ceramics produced from the heat treatment of pig bones. Methods: The properties of natural HA ceramics produced from pig bones were assessed in two parts. Firstly, the raw materials were characterized. A temperature of $1,200^{\circ}C$ was chosen as the calcination temperature. Fine bone powders (BPs) were produced via calcinations and a milling process. Sintered BPs were then characterized using field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared (FTIR) spectroscopy, and a 2-year in vitro degradability test. Secondly, an indirect cytotoxicity test was conducted on human osteoblast-like cells, MG63, treated with the BPs. Results: The average particle size of the BPs was $20{\pm}5{\mu}m$. FE-SEM showed a non-uniform distribution of the particle size. The phase obtained from XRD analysis confirmed the structure of HA. Elemental analysis using XRF detected phosphorus (P) and calcium (Ca) with the Ca/P ratio of 1.6. Functional groups examined by FTIR detected phosphate ($PO{_4}^{3-}$), hydroxyl ($OH^-$), and carbonate ($CO{_3}^{2-}$). The EDX, XRF, and FTIR analysis of BPs indicated the absence of organic compounds, which were completely removed after annealing at $1,200^{\circ}C$. The BPs were mostly stable in a simulated body fluid (SBF) solution for 2 years. An indirect cytotoxicity test on natural HA ceramics showed no threat to the cells. Conclusions: In conclusion, the sintering temperature of $1,200^{\circ}C$ affected the microstructure, phase, and biological characteristics of natural HA ceramics consisting of calcium phosphate. The Ca-P-based natural ceramics are bioactive materials with good biocompatibility; our results indicate that the prepared HA ceramics have great potential for agricultural and biological applications.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.737-745
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• 1996

In recent years, with the increase in the consumption of natural resources and energy, global environmental problems have appeared. This is a very serious environmental load on worldwide food production. For this reason, innovative techniques for production of low entropy by using effectively the energy for the ecosystemic agriculture have been expected. In this study, granular ceramics of 2 to 3mm in diameter having electrical charges at the surface were produced, using the natural raw materials of silicate minerals haing excellent moldabilities and sintering properties . Production of water having functions was attempted by effective use of the electrochemical energy of the ceramics with an efficient water treatment apparatus in which the ceramics were fluidized in water, differently from conventional systems. In the experimental results, the EC of water treated with the ceramics was not changed, but the ORP and also the pH and the DO were changed. The speed of oxidation -re uction reaction was high, and the ceramics -treated water enhanced the vigor of seeds. It can be expected that this treatment system, by which the ORP of water can be moderately controlled, is advantageous in controlling the growth of plants.

• 접착 및 계면
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• 제14권3호
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• pp.128-134
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• 2013

본 연구에서는 합성수지 접착제를 대체하여 토기 유물에 활용할 수 있는 천연접착제를 개발하기 위해 옻과 아교를 배합하여 시료를 제조하였고 이에 대한 구조적 물리적 특성을 분석하였다. 구조분석 결과 옻에 배합하는 아교의 비율이 높아질수록 carbonyl (C=O), amine (N-H), aromatic (C=C) 결합이 증가하는 것을 확인하였다. 또한 제조한 천연접착제를 합성수지 접착제와 비교하였을 때 낮은 접착강도를 가진 Paraloid B-72부터 높은 접착강도의 Araldite rapid type에 상응하는 다양한 점도와 접착강도를 가지고 있음을 확인하였다. 이를 바탕으로 하여 향후 체계적이고 심화된 분석이 이루어 진다면 훼손된 토기 유물의 접착 및 복원을 위한 친환경 천연접착제의 실용화가 가능할 것으로 사료된다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2002년도 춘계학술대회논문집
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• pp.53-57
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• 2002

In this paper, we explain new EM(electromagnetic) wave absorber that mixed NC (Natural Ceramics) and Ferrite with NL(Natural Lacquer). At first, a mixed NC and Ferrite(NC : F = (0.1~30)wt% : (99.9~70)wt%) bum at 95$0^{\circ}C$~125$0^{\circ}C$. And then, it is comminuted and injected into NL((NC+F) . NL = (30~80)wt% (70~20)wt%), finally we made Ferrite-NL EM wave absorber. Generally, conventional labor Ferrite covers only 500 MHz to 10 GHz under tolerance limits of 2 to 6 dB in absorption, and Ferrite-NL is over 8 ~ 14 dB. However, NCFerrite-NL huts superior absorption ability. It is over 16 to 19 dB through 500 MHz to 10 GHz.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1996년도 춘계학술대회 논문집
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• pp.41-46
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• 1996

In this study, unsintered and pre-sintered low purity alumina ceramics were machined with various tools to clarify the machinability, optimum tool materials and optimum cutting conditions. The main conclusions obtained were as follows. (1)In the case of dry cutting, the sintered diamond and natural diamond tools exhibit better performance in machining of the ceramic pre-sintered at lower temperature, and the tool lives of both tools in machining the ceramics pre-sintered at high temperature becomes extremely short. (2)The performance of CBN tool becomes better in dry machining of the ceramics pre-sintered at higher temperature. (3)When the pre-sintered ceramics were wet machined with sintered diamond, the tool life becomes considerably long, and higher cutting speed can be used than in the case of the CBN and ceramic tools, the tool lives becomes shorter at wet cutting than at dry cutting, especially exhibiting extremely short tool life in wet cutting with ceramic tool.

• 한국지반환경공학회 논문집
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• 제18권12호
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• pp.25-36
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• 2017

본 연구에서는 천연 제올라이트와 제강전로슬래그를 혼합 소성한 ZS 세라믹을 이용한 산성광산배수 내 중금속 및 황산이온의 제거 특성을 파악함으로써 산성광산배수 처리를 위한 ZS 세라믹의 적용 가능성을 평가하고자 하였다. 펠렛형 ZS(Zelolite-Slag) 세라믹을 이용한 회분식 실험에서 ZS 세라믹 내 천연 제올라이트에 대한 제강전로슬래그의 배합비가 증가할수록 중금속 제거효율 및 황산이온의 제거효율은 증가하였다. ZS 세라믹의 결합력 및 알칼리 공급능력, 중금속 및 황산이온 제거능력, 에너지 비용 측면에서 평가할 때 산성광산배수의 처리를 위한 ZS 세라믹의 최적의 제작 조건은 Z:S 배합비 1:2~1:3, 소성온도 $600{\sim}800^{\circ}C$, 소성시간 2시간인 것으로 파악되었다. 최적의 조건에서 제작된 ZS 세라믹에 의한 산성광산배수 처리 실험결과 중금속(Al, As, Cd, Cu, Fe, Mn, Pb, Zn)은 거의 100%에 가까운 매우 높은 제거효율을 얻을 수 있었으며, 황산이온에 대해서는 77.1%의 제거효율을 나타내고 있었다. 본 연구의 실험결과를 통해 판단해 볼 때 천연 제올라이트와 제강전로슬래그를 혼합 소성한 ZS 세라믹은 산성광산배수의 효과적인 처리제로서 적용될 가능성이 높을 것으로 기대된다.

• 한국세라믹학회지
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• 제41권8호
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• pp.628-632
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• 2004

생체친화성 인공골 개발을 위하여 해면골과 매우 유사한 기공구조를 갖는 천연 산호(CaCO$_3$, aragonite phase)를 수열처리하여 수산화아파타이트 다공체를 제조하였다. 생체 친화성을 증진시키기 위하여 산호를 수열 처리하는 과정에서 실리콘을 치환시키는 실험을 하였다. 수열합성과 solvothermal 방법을 반복적으로 사용하여 실리콘이 치환된 수산화아파타이트를 합성하였으며 이들의 각 온도에 따른 상변화 및 실리콘 농도를 XRD, ICP, EDS 등을 통하여 분석하였다. 분석결과로부터 실리콘이 수산화아파타이트 골격 내에 균일하게 분산되어 있음을 확인하였다.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 1986년도 Priceedings Of The Third Korea-Japan Seminar On New Ceramics
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• pp.156-161
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• 1986

Sialon $Si_3N_4$ and SiC powders and ceramics were prepared from Korean natural resources. The properties of the powders and sintered ceramics obtained in this work are considered to be comparable to those of foreign articles.