• Proceedings of the Korean Fiber Society Conference
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• 2003.10a
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• pp.71-72
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• 2003

The aim of our study is to prepare nanocomposites consisting polymer/inorganic nanoparticles and investigate their physical properties as a functional material. In this study, a nanocomposite of copper sulfide (CuS) nanoparticles introduced into a poly(acrylic acid) matrix was prepared and the optical absorption property was measured. The composite exhibited strong absorption of both ultraviolet and near-infrared rays, indicating that the composite is applicable to a solar radiation shielding filter. The wavelength of the near infrared absorption was controlled from ca.1000 nm to 1700 nm by heat and acidic solution treatments.

• Progress in Superconductivity
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• v.4 no.2
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• pp.121-126
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• 2003

The single layer direct-coupled YBCO SQUID magnetometers have been fabricated and characterized for the purpose of the measurement of weak magnetic signals in unshielded environment. Two types of magnetometers have been designed and fabricated using 10 mm$\times$ 10 mm substrates. We could operate the conventional 3-mm-wide solid pickup loop magnetometers more stably than the 12-parallel-line pickup loop magnetometers in laboratory environment. We developed a first-order electronic gradiometer system using the SQUID sensors with axial displacement of 80 mm without any mechanical alignment of magnetometers. The system with a software filter using calculation of discrete Fourier transform could record clearly weak pulse signal of 100 pT in a magnetically disturbed environment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.961-963
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• 2002

Organic electroluminesencent device have been studied because of its easy fabrication and high brightness for plate panel display instead of cathode ray tube. There are some device structure for full color filter system can be applicable to the full color application if the blue light organic electroluminesencent device(OELD) is developed. In this study, we fabricated OELD of ITO/CuPc/PBD/LiF/Al using mixed of 500, 600, $700[{\AA}]$ by vacuum method as a emitting layer. We studied the voltage-current, voltage-luminance characteristics and blue light emission of OELD,

• Journal of radiological science and technology
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• v.12 no.1
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• pp.17-23
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• 1989

We have developed of the exposure technique for the chest radiography to get different contrast in left and right lung fields simultaneously for the effective diagnosis, I.E., get high contrast to detect tuberculosis, dispersal shadow or exudative lesions of early tuberculosis and get better sharpness and wider latitude to detect growing lesions of lung cancer or lesions overlapped with bones. As a result, by using an additional filter Cu 1.2mm with BX-III screen side and sheet of yellow cellophane on BF-III screen side at the conventional KV ($80KV{\sim}100KV$) for the chest X-ray, we can get similar densities in both left and right lung fields and, thus, this method is considered to be very effective for the quality diagnosis for the routine chest radiography.

• Fashion & Textile Research Journal
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• v.6 no.3
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• pp.384-392
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• 2004

The purpose of this study is in development of effective filter-type polymer adsorbent for removal of pollutants from wastewater by UV irradiation graft polymerization. Photografting of acrylic acid (AA) on polypropylene (PP) nonwoven fabric using benzophenone (BP) as a photosensitizer was investigated. Inhibition of homopolymerization was achieved by adding various concentrations of $FeSO_4{\cdot}7H_2O$, $CuSO_4{\cdot}5H_2O$ and Mohr's salt. As AA concentration was increased, the degree of grafting was increased as to a specific value and then decreased, and the effect of BP concentration showed the same tendency. It was also found that the degree of grafting increased with reaction time and reaction temperature. Addition of the polyfunctional monomers and $H_2SO_4$ to the grafting system accelerated the photografting. The melting temperature, molecular weight and breaking stress and breaking strain were decreased with the increase in the degree of grafting.

• Bulletin of the Korean Chemical Society
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• v.29 no.2
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• pp.389-392
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• 2008

High purity carbon nano fibers/tubes (CNF/Ts) which contain 97% pure graphitic carbon are prepared by a new catalytic method. These carbon nano fibers/tubes are ready to use without any further purification. The striking feature of this method is the production of carbon nano fibers/tubes of narrow distribution range. The developed catalytic method also produces pure hydrogen. An additional advantage of this catalytic method is that catalyst can be reused without reactivation. Ni:Cu catalyst system is embodied into SCHOTT-DURAN filter disc of large pore size (40-100 mm). Due to the production of hydrogen in the reaction catalyst stability is enhanced and deactivation process is considerably slowed down.

• Environmental Engineering Research
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• v.9 no.5
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• pp.193-200
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• 2004

A study of the treatment of piggery wastes using a multilayered metal-activated carbon system followed by carbon bed filtration was carried out at bench scale. From the physicochemical properties obtained from samples treated with aqueous solutions containing metallic ions such as Ag$^+$, Cu$^{2+}$, Na$^{-}$, K$^+$ and Mn$^{2+}$, main inspections are subjected to isothem shape, pore distribution with micropore, SEM and EDX. Multilayered metal-activated carbons were contacted to waste water to inwestigate the simultaneous catalytic effect for the COD, BOD, T-N and T-P removal. From these removal performance was achieved. The high efficiency of the multilayered metal-activated carbon bed, satisfactory removal performance was achieved. The high efficiency of the multilayered metal-activated carbon bed was derermined by the properties of this material for trapping, catalytic effect and adsorption of organic solid particles.

• The Journal of the Acoustical Society of Korea
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• v.17 no.8
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• pp.41-47
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• 1998

이중 통신(Duplexer) 필터를 설계 및 개발하기 위한 최적조건을 구하기 위해 36° LiTaO3 기판 표면에 빗살무늬 변환기를 사용한 모의 실험을 수행하였으며, 전극 재료로는 Cu-Al(W3%)합금을 이용하였다. 제작한 듀플렉스 필터의 사다리(Lader)형 구조로서 직렬 공진기와 병렬 공진기의 결합으로 필터를 구성하였다. 적절한 통과대역과 저지대역을 형성 하기 위하여 직렬 공진기와 병렬 공지기의 주파수 차이를 30MHz로 했으며, 낮은 저지대역 을 형성하기 위하여 두 공진기의 전기용량의 비는 1로 하였고, 전극의 두께는 2,500Å으로 하였을 때 설계 조건과 일치하는 주파수 응답을 얻었다. 제작한 듀플렉서 필터의 주파수 특 성은 중심 주파수는 836.5MHz와 881.5MHz, 통과대역 폭은 25MHz, 삽입손실은 2.5dB 이하 및 저지대역은 -35dB이하로 나타났다.

• Journal of the Korean Ceramic Society
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• v.29 no.8
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• pp.639-645
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• 1992

Effects of additives on electromagnetic properties of a Ni-Cu-Zn ferrite for a noise filter in high frequency regions were studied. Both resistivity and permeability were increased with the amount of Mn2O3 up to 1wt%, then decreased with further addition. Addition of Co2O3 decreased the permeability of the ferrite and shifted the resonance frequency to a higher frequency region, which was thought due to the stabilization of domain walls. Therefore it was possible to improve both the permeability and the loss and to control the cut-off frequency by the concurrent addition of Mn2O3 and Co2O3.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.425-428
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• 2000

본 논문에서는 영동산 일라이트가 갖는 기능성을 이용하여 정수기용 필터로써의 가능성을 검토한다. 대장균 실험을 통하여 항균성을 평가하였고, 여러 가지 중금속(Zn, Pb, Cu, Cd, Fe$^{2+}$)의 흡착능력을 평가하였다 정수기 필터재료로 사용하기 위한 성형조건을 실험하였고, 물 필터하우징에 성형된 illite ceramic을 충진하여 물을 정수 처리하여 버섯 재배에 적용하였다. 결과적으로 항균성은 white-yellow-red 순이었고 중금속흡착능력은 원소에 따라서 yellow가 white보다 크게 나타났고, 이에 착안하여 버섯재배에 적용한 결과 수율 향상에 크게 기여하는 것으로 나타났다. 본 논문에서 illite ceramic이 필터재료로서의 가능성을 나타내고 이를 개발, 보고 하고자 한다.