CaCO₃을 이용한 혼합매질분리막의 이산화탄소 투과도 향상

박철훈,정정표,이재훈,김종학,Park, Cheol Hun,Jung, Jung Pyo,Lee, Jae Hun,Kim, Jong Hak 한국막학회 2018 멤브레인 Vol.28 No.1

급진적인 산업발전에 따른 무분별한 이산화탄소 배출로 인하여 지구온난화, 이상 기후 등의 문제가 불거지고 있으며 이는 한 나라에만 국한되지 않은 국제적인 문제가 되었다. 위와 같은 문제를 해결하고자 본 연구에서는 이산화탄소에 대해 높은 친화도를 가지고 있는 PEGBEM-g-POEM 가지형 공중합체를 합성하였으며 $CaCO_3$염을 첨가하여 염의 중량에 따른 혼합매질분리막의 이산화탄소/질소 투과 성능을 관찰하였다. $CaCO_3$염이 고분자 중량 대비 50% 첨가되었을 때 최적의 이산화탄소/질소 분리 투과성능을 보였으며, 선택도는 염을 추가하기 전 44.7에서 45.42로 크게 변하지 않은 반면 이산화탄소 투과도는 염을 첨가하기 전 22.5 GPU에서 28.16 GPU로 약 25% 향상되었다. 이는 첨가한 염과 이산화탄소간의 상호작용으로 인하여 향상된 고분자 복합막의 이산화탄소에 대한 용해도에 기인하는 것으로 생각된다. 또한 염을 과량으로 첨가한 경우에는 고분자가 복합막의 표면을 충분히 메우지 못하여 계면결함이 생성되었으며 이로 인해 이산화탄소 기체 분리성능이 감소하였다. 기체분리성능 향상을 위해서는 적정량의 염 첨가가 필수적인 것으로 분석되었다. With vigorous development of petroleum and chemical industry, emission of carbon dioxide has attracted tremendous attention globally due to global warming problem and abnormal climate change. To address these problems, in this study, a PEGBEM-g-POEM graft copolymer with high $CO_2$ affinity was synthesized and $CaCO_3$ was incorporated to form mixed matrix membranes (MMMs) for enhancement of $CO_2$ permeance. By varying the addition weight of $CaCO_3$ in MMMs, high separation performance of $CO_2$ over $N_2$ was obtained. At 50 wt% loading of $CaCO_3$, the greatest separation performance was obtained with an enhanced $CO_2$ permeance from 22.5 to 28.16 GPU and slightly increased $CO_2/N_2$ selectivity from 44.7 to 45.42. It resulted from the increased $CO_2$ solubility of MMMs due to specific interaction between $CaCO_3$ and $CO_2$ molecules. Upon excess loading of $CaCO_3$, MMMs exhibited loss of $CO_2$ separation performance due to the formation of interfacial defects. Based on this result, it is considered that the proper addition of $CaCO_3$ is crucial for improvement of $CO_2$ separation performance.

증례 : 과점조도증후군을 동반한 IgA 다발성골수종 1 예 보고

이성동 ( Sung Dong Lee ),여운재 ( Woon Jae Lyo ),정정표 ( Jung Pyo Chung ) 대한내과학회 1976 대한내과학회지 Vol.19 No.6

NC 선반의 평면 운동정도 측정장치의 개발

김영석(Young Seuk Kim),한지희(Ji Hee Han),정정표(Jung Pyo Jung),윤원주(Won Ju Yun),송인석(In Suk Song) Korean Society for Precision Engineering 2004 한국정밀공학회지 Vol.21 No.7

Measurements of linear motion accuracy for one axis of NC lathe have achieved with laser interferometer system, but measurement of plane motion accuracy for two axes on zx-plane of NC lathe have not achieved with the above system. Therefore in this study, measuring unit system is organized using two optical linear scales in order to acquire error data during of plane motion of ATC(Automatic Tool Changer) of NC lathe by reading zx-plane coordinates. Two optical linear scales of measuring unit are fixed on zx-plane of NC lathe, and moving part of the scales are fixed to the ATC and then error motion data of z, x-coordinates of the ATC are received from the scales through the PC counter card inserted in computer at constant time intervals using tick pulses coming out from computer. And then, error motion data files acquired from measuring are saved in computer memory and the aspect of plane motion are modeled to plots, and range of the error data, means, average deviations, and standard deviations etc. are calculated by means of statistical treatments using computer programs.

Head CT 검사 시 안구 차폐용 Bismuth사용에 의한 수정체 선량 감소에 대한 평가

조평곤(Pyong-Kon Cho),김유현(You-Hyun Kim),최인자(In-Ja Choi),정정표(Jung-Pyo Chung),장상규(Sang-Gyu Chang),이현(Hyun Lee),김장섭(Jang-Seob Kim),신동철(Dong-Cheol Shin),최종학(Jong-Hak Choi),이기성(Ki-Sung Lee),이원호(Won-Ho Lee) 대한방사선과학회(구 대한방사선기술학회) 2008 방사선기술과학 Vol.31 No.2

  본 연구는 두부 전산화 단층촬영 시 차폐용 bismuth를 사용하여 수정체 선량의 감소와 차폐용 bismuth의 유용성을 평가하기 위해 수행되었다. 인체모형 팬텀과 열형광 선량계를 이용하여 (a) 안구를 포함한 두부 CT촬영 (b) 두부 전체가 포함된 CT촬영 (c) 안구를 배제하고 20°를 준 두부 CT촬영 시의 수정체 선량을 평가하였다. 수정체 선량의 감소효과는 안구를 포함한 두부 CT촬영에서 43.2%, 두부 전체가 포함된 CT촬영에서 36.0%, 20° 각도를 준 두부 CT촬영에서 1.4%로 나타나 두부 전체가 포함된 CT촬영과 안구를 포함한 두부 CT촬영에서는 상당한 감소효과가 있지만 안구를 제외한 20° 각도를 준 두부촬영에서는 감소효과가 적었다. 즉, 차폐용 bismuth를 사용한 수정체 선량감소는 안구가 촬영부위에 포함된 경우에는 유의한 것으로 나타났으나 안구가 포함되지 않은 두부 CT촬영일 경우에는 유의하지 않은 것으로 나타났다. 따라서 두부 CT촬영 시차폐용 bismuth의 사용은 안구가 포함되는 일부의 CT촬영에서만 제한적으로 사용되는 것이 바람직하다.   The aim of this study is to assess the dose reduction of eye lens and availability of bismuth garments resulting from the use of radioprotective bismuth garments to shield the eyes of patients undergoing head CT. Rando phantom and TLDs were used to determine the amount of dose reduction by bismuth shielding of the eye in the following simulated CT scans: (a) scanning of the head including orbits, (b) scanning of the whole head, and (c) 20° angled scanning of the head excluding orbits.<BR>  The average dose reduction of eye lens was 43.2%, 36.0% and 1.4% for the three CT scans listed above. Significant reduction in the eye lens dose was achieved by using superficial orbital bismuth shielding during head CT scans. However, bismuth shields should not be used for the patients when their eyes are excluded from the primarily exposed region.

증례 : 선천성 개방성동맥관이 합병된 단측성우측 폐동맥부재의 1 예 보고

차홍도 ( Hong Do Cha ),노원식 ( Won Sik Loh ),김성순 ( Sung Soon Kim ),선우일남 ( Il Nam Sunwoo ),정정표 ( Jung Pyo Chung ) 대한내과학회 1976 대한내과학회지 Vol.19 No.4

NC 선반의 직선 사이클 평면 위치결정 정도 측정 및 분석

김영석,정정표,한지희,윤원주 朝鮮大學校 機械技術硏究所 2003 機械技術硏究 Vol.6 No.2

It is very important t o measure linear cycle plane positioning accuracy of NC lathes because the plane positioning accuracy affects accuracy, performance, interchange-ability and quality of machine parts machined by the NC lathes in industries. Until now, linear cycle plane positioning accuracy test of NC lathes has not been carried out because the two axes of NC lathe are moving simultaneously crossing a t right angle each other. while positioning accuracy test of one axis of NC lathe is briskly carried out using a laser interferometer system in industries. So, in this study, a measuring units system to measure simultaneously two axes' plane. positioning accuracy of NC lathe was composed of two optical linear scales installed on the. z and x-axis of work coordinate system on NC lathe and a computer inserted with PC counter card enables to obtain measuring data. Here, ATC(Automatic Tool Changer) and moving part of linear scale are fixed with magnet bases in order to measure displacement of the ATC of NC lathe. And next, computer software was developed in order to measure the lathe under resolution of 0.1㎛ by the linear scales, and also computer soft measuring data could be modeled on plots and be analyzed to numerically.

NC 선반의 직선 사이클 평면 위치결정 정도 측정에 관한 연구

김영석,송인석,정정표,한지희,윤원주 한국공작기계학회 2003 한국생산제조학회지 Vol.12 No.2

It is very important to measure linear cycle plane positioning accuracy of NC lathe as it affects all other parts of machines machined by them in industries. If the plane positioning accuracy of NC lathe is bad, the dimension accuracy and the change-ability of works will be bad in the assembly of machine parts. In this paper, computer software systems are organized to measure linear cycle plane positioning displacements of ATC(Automatic tool changer) on zx plane of NC lathe using two linear scales and the time pulses comming out from computer in order to get data at constant time intervals from the linear scales. And each sets of error data obtained from the test is discripted to plots and the results of linear cycle plane positioning errors are expressed as numerics by computer treatment.

리니어 스케일을 이용한 NC 선반의 원 운동정도 측정 시스템의 구성

김영석,김재열,김종관,한지희,정정표 한국공작기계학회 2004 한국생산제조학회지 Vol.13 No.5

Measurements of circular motion accuracy of NC lathe have achieved with ball bar systems proposed by Bryan, but the ball bar systems have influenced on the measuring data by way of the accuracy of the balls and the contacts of balls and bar seats. Therefore in this study, error data during of circular motion of ATC(Automatic Tool Changer) of NC lathe will be acquired by reading zx plane coordinates using two optical linear scales. Two optical linear scales of measuring unit are fixed on z-x plane of NC lathe, and the moving part is fixed to ATC and then is made to receive data of coordinates of the ATC at constant time intervals using tick pulses comming out from computer. And then, error data files of radial direction of circular motion are calculated with the data read, and the aspect of circular motion are modeled to plots, and are analysed by means of statistical treatments of circularity, means, standard deviations etc.

NC 선반에서 직선 사이클 평면 위치결정 정도 측정 시스템의 구성

김영석,김재열,송인석,곽이구,정정표,한지희 한국공작기계학회 2002 한국공작기계학회 추계학술대회논문집 Vol.2002 No.-

It is very important to measure linear cycle plane positioning accuracy of NC lathes as they affect those of all other machines machined by them in industries. For example, if the linear cycle plane positioning accuracy of each, axes directions is had, the accuracy of works will be wrong and the change-ability will be bad in the assembly of machine parts. In this paper, computer software systems are organized to measure linear displacements of ATC(Automatic tool changer) of NC lathes using linear scale and time pulses comming out from computer in order to get data at constant time intervals from the sensors. And each sets of error data gotten from the test is expressed to plots by computer treatment and the results of linear cycle plane positioning error motion estimated to numerics by statistical treatments.