다공성 매질내에서 CMC로 표면개질된 영가철 나노입자의 이동 특성에 관한 연구

조윤철,최상일,Cho, Yun-Chul,Choi, Sang-Il 한국지하수토양환경학회 2009 지하수토양환경 Vol.14 No.6

카르복시메틸 셀룰로즈(carboxymethyl cellulose, CMC)와 같은 안정화제는 오염된 지하대수층에서 영가철 나노입자의 이동을 촉진할 수 있다. 본 연구에서는 CMC로 개질된 영가철 나노입자의 이동성을 컬럼실험을 통해 조사하였다. CMC로 개질된 100 mg/L 영가철 나노입자는 모래로 이루어진 공극매체에서 이동이 가능하였다. 하지만 비개질된 영가철 나노입자는 제조된 용액에서 쉽게 엉김현상이 나타났고, 모래로 이루어진 공극매체에서 통과하지 못했다. pH가 7일 때 영가철 나노입자 약 80%가 컬럼을 통과하여 흘러나왔다. pH가 5이하로 감소할 때는, 100%의 CMC로 개질 된 영가철 나노입자는 100%가 흘러나왔다. 이온강도세기 실험에서 $Na^+$과 $Ca^{2+}$ 이온의 농도가 증가함에 따라 CMC로 개질된 영가철의 이동성이 다소 감소하는 것으로 나타났다. 점토과 자연유기물(natural organic matter, NOM) 영향 실험에서는, 1과 5%의 점토와 100과 1000 mg/L의 자연유기물질은 CMC로 개질된 영가철 나노입자의 이동성에는 크게 영향을 주지 못하는 것으로 나타났다. 본 실험의 결과로부터 CMC로 개질된 영가철 나노입자는 다양한 이온세기, 자연유기물농도 및 점토함량을 가진 토양내에서도 효과적으로 이동될 것으로 기대된다. Carboxymethyl cellulose (CMC) as stabilizer is expected to facilitate in-situ delivery of zero-valent iron (ZVI) nanoparticles in a contaminated aquifer because it increases dispersity of ZVI nanoparticles. This work investigated the transport of CMC-stabilized ZVI nanoparticles (CMC-Fe) using column breakthrough experiments. The ZVI nanoparticles (100 mg/L Fe) were transportable through sand porous media. In contrast, non-stabilized ZVI nanoparticles rapidly agglomerate in solution and are stopped in sand porous media. At pH 7 of solution approximately 80% CMC-Fe were eluted. When the pH of solution is below 5, 100% CMC-Fe were eluted. These results suggest that the mobility of CMCFe was increased as pH decreases. In the mobility test under different ionic strengths using $Na^+$ and $Ca^{2+}$ ions, there was no signigficant difference in the mobility of CMC-Fe. Also, in the experiments of effect of clay and natural organic mater (NOM) on the mobility of ZVI, there was no significant difference in the mobility of CMC-Fe not only between 1 and 5% clay, but 100 and 1000 mg/L NOM. The results from this work suggests that the CMC-Fe nanoparticles could be easily delivered into the subsurface over a broad range of ionic strength, clay and NOM.

2P-511 A Preliminary Study on the Fabrication of 3D Printable Electrode Ink for Li-ion Batteries

조윤철,강석현,이창우 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.1

With advent of the forth industrial revolution, 3D printing technic has become emerging technology along with internet of things (IoT), artificial intelligence (AI) and so on. Various shape of batteries would be required that could be applied to variety of things which did not require the energy source in the past. In this study, we have focused on optimization of composition and rheology for electrode ink. The electrode which is fabricated by attempted electrode ink is characterized and compared with the electrode produced by traditional method.

사진과 저작권

조윤철 한국사진학회 1999 AURA Vol.6 No.1

Raw 파일 변환을 통한 디지털 존 시스템

조윤철,하동환,손영호 영상예술학회 2006 영상예술연구 Vol.9 No.-

유기점토를 이용한 p-자일렌 흡착 제거

조윤철,김태성,한선기,이채영 대한상하수도학회 2012 상하수도학회지 Vol.26 No.6

The purpose of this study was to investigate adsorption characteristics of organo-clays for removal of p-xylene. As part of efforts to examine the adsorption capacities of some organo-clays for p-xylene, batch isotherm tests were carried out. Organo-clay minerals were synthesized under hydrothermal conditions using Na-montmorillonite as host clay and dimethyldioctadecylammonium (DMDA) bromide and benzyldimethyldodecylammonium (BDDA) chloride as organic surfactants, respectively. All synthetic organo-clay minerals were characterized by powder x-ray diffraction (XRD), scanning electron microscope (SEM) and energy-dispersive x-ray spectroscopy (EDX). The modification using dimethyldioctadecylammonium (DMDA) bromide showed the higher adsorption ability for p-xylene than benzyldimethyldodecylammonium (BDDA) chloride. On the other hand, the maximum adsorption capacity, Qmax of DMDA modified montmorillonite estimated by Langmuir model was 27.0 mg/g, which was the higher value than other organo-clays.

자외선 사진 연구

조윤철 한국사진학회 2000 AURA Vol.7 No.1

Many scientists informed us not only that light helps us to see a thing but also that it includes invisible light which can hardly be conceived but exists still as a part of light. Among the pictures using such invisible light, ultraviolet picture is one of the most commonly known type together with infrared photography. The main purpose of the ultraviolet photography lies in providing information unavailable from other photographs using other lights such as visible light and infrared light. Unlike the way of visible light to show the peculiar color in things through reflection and extinction of the light, some things absorb ultraviolet light, while other things reflect it, fully or partially. This kind of effect can be recorded in the ultraviolet photos. Presently, in terms of infrared picture, it is rather well-known and many good works of such photos have been introduced in Korea. However, compared to it, ultraviolet photo seems to be relatively unfamiliar. Thus, I've tried to introduce the use of ultraviolet light in photograph, focusing on the fact that such invisible but definitely existing part of light responds to most of the currently used photographic emulsion. Considering that we photographers are more interested in creative use of such technique for more diverse and colorful works in its application, than the experimental characteristics of scientific pictures. If we take it over and develop it in other ways helpful for the creation of original works. it will furnish us with quite useful tool for indefinite variations.

공기중에서 지르칼로이 산화 거동 : 흡착물의 영향 Effects of Adsorbate

조윤철,박광헌 慶熙大學校 材料科學技術硏究所 1994 材料科學技術硏究論集 Vol.7 No.-

In order to get the results about the data for the corrosion of the Zircaloy-4 specimens which were purely etched, adsorbated on the LiOH and NaCl, and oxidized to the "Post-Transition" point in air, the specimens were oxidized in the electrical furnace set at the temperature of the 400℃, 450℃, and 500℃ for long time(approximately 700 hours). According to the results of the oxidation velocities among the specimens, the velocities of the adsorbated specimens on the NaCl, LiOH and the post-transition showed higher than the specimens of the purely etched specimens. Compared to the results of the Suzuki, the results of the purely etched specimens showed close similiarity to each other.

뇌 종양내 항암제 치료를 위한 항암제 방출용 생분해성 폴리머 개발- 체외실험 결과

조윤철,조한진,안정호,이원정,윤수한 대한신경외과학회 2004 Journal of Korean neurosurgical society Vol.35 No.4

Objective : The authors present two polymers as carriers of anti-neoplastic agents for intratumoral chemotherapy. We investigated in vitro tumor cytotoxicity againt C6 glioma cells with 20ul cis-platinum(CDDP)-polymer. Methods : We firstly developed new two thermosensitive sol-gel reversible polymer(poly-2 and poly-6) by random copolyerization from ethylene glycol and caprolactone polymer that is sol state over 50°C but changed gradually to gel less than 50°C We evaluated the time-related release profiles of 10mg cisplatin from CDDP-Poly 2 and CDDPPoly 6 in 25ml of pH 7.4 phosphate buffer saline using UV spectrophotometer during 31days. We cultured C6 glioma cell line in 10cm round plates for 2 days and added 20㎕ of CDDP-polymer containing 30uM of CDDP into the center of each plate. We counted C6 cell number every 12 hours for 72 hours at same 3 sites of each 6 well plates. Results : UV spevtrophotometry showed total 12.6% of CDDP released from CDDP-poly2 and total 56.9% of CDDP from CDDP-poly6 on 31 days. Both carrier polymer showed total released amount of CDDP directly correlated with time without initial dumping effect. The CDDP released from 20㎕ of CDDP-poly2 and CDDP-poly6 in 48 hours showed cytotoxicity to C6 glioma cells more than 50% in vitro cell culture system. Conclusion : This results suggest that less than 20㎕ CDDP-polymer could be applied in vivo brain tumor model to show significant cytotoxicity.

가변구조 제어기를 이용한 인공위성의 자세 제어 ( Attitude Control of Satellite by Variable Structure Controller )

조윤철,박수홍,조겸래 대한전자공학회 1990 대한전자공학회 학술대회 Vol.1990 No.01

해군 빅데이터 분석체계 발전방향

조윤철 대한조선학회 2020 大韓造船學會誌 Vol.57 No.1