인공 및 천연 CaCO₃의 염료흡착 특성

조명찬 東西大學校 2000 동서논문집 Vol.6 No.-

원주의 가공기술을 개발하기 위한 초기 연구로써 진주 층 및 삽입 핵(CaCO3)을 사용하여 염료의 흡착 특성을 조사해 보았다. 진주 염색에 사용되는 것으로 알려져 있는 Rhodamine 6G, Rhodamine B, Methylene Blue를 염료로 선택하여 물, 메탄올, 에탄올, 아세톤 등의 용매를 사용하여 용해시킨 결과 염료용액 제조시 염료의 용해도로 인한 문제는 없는 것으로 판단되었다. 진주 층과 삽입 핵(CaCO3)을 60 micron크기로 파쇄한 후 Porosimeter를 사용하여 기공크기 면적과 내부표면적을 측정해 보았다. 측정 결과 기공크기, 기공체적, 내부표면적은 진주 층의 경우 대략 100 Å, 0.035 cm3/g, 1 m2/g, 삽입 핵은 대략 200 Å, 0.0116 cm3/g, 2m2/g 정도인 것으로 나타났다. Rhodamine 6G를 염료로 사용하여 진주 층과 삽입 핵에의 회분식 흡착 실험 결과 대략 20시간과 30시간 후에 각각 평형에 도달하는 것으로 나타났다. 평형 흡착 능의 경우 삽입핵에의 흡착 량은 진주 층에의 흡착 량의 약 20%에 해당되는 것으로 나타나 진주 핵에도 염료가 일부 흡착된다는 사실을 확인하였다. 탈착실험 결과 탈착률은 대략 13% 정도로 동일하나 삽입 핵의 탈착 평형 시간은 대략 10시간 정도로 진주 층의 50시간에 비해 5배 빠른 것으로 나타났다. This study represents characteristics of dye adsorption onto pearl and pearl nucleus (CaCO3). Three basic dyes such as Rhodamine 6G, Rhodimine B, and Methylene Blue were selected as model compounds for adsorption experiments because they were known to be used for processing pearls. Solubility of the dyes were investigated with various solvents such as distilled water, methanol, ethanol, and acetone and were found to be out of the range of precipitation. Pearl and pearl nucleus were reduced to powder of 60 ㎛ size and the pore characteristics of the powders were investigated using porosimeter. The pore size, pore volume, and surface area were found to be approximately 100 Å, 0.035 cm3/g, 1 m2/g for pearl and 200 Å, 0.0116 cm3/g, 2m2/g for pearl nucleus. From the batch adsorption experiment using Rhodamine 6G, it was found that equilibrium reached after 20 hours for pearl and 30 hours for pearl nucleus, respectively. Adsorption loading for pearl was 5 times larger than that for pearl nucleus. Desorption experiment showed that desorption percent was 13% for both adsorbents. However, time for desorption equilibrium for pearl nucleus was 10 hours and was 5 times shorter than that for pearl.

피혁폐수의 수질오염 현상에 관한 고찰

조명찬,노병일,신춘환 동서대학교부설연구소 1997 연구소 논문집 Vol.2 No.-

피혁의 최종처리공정 중 코딩공정은 피혁제품의 품질을 결정하는 중요한 기술로 자리잡고 있다. 피혁 코팅에 사용되는 수지들은 분산매의 종류에 따라 유성 Polyurethane(PU) 계열 및 수성 PU계열로 크게 구별되며 근래에 와서는 작업환경의 개선 및 환경오염 방지 측면에서 수용성 PU의 사용이 보편화 되면서 이들의 수질오염에 미치는 영향을 제시할 필요성이 대두되었다. 따라서 본 실험에서는 수용성 PU가 수계에 유입되었을 경우 COFD, BOD, SS의 상승효과를 측정함으로써 기초자료로 활용하고자 하며 특히 수용성 PU는 polyol 및 diisocyanate의 중 부가반응에 의해 생성되는 고분자 물질로서 수중에서는 분자 Chain이 절단되는 aging effect현상이 현저할 것으로 예상하여 수용성 PU가 유입된 수계의 aging effect와 BOD 및 COD와의 상관성을 도출하여 방류수 처리의 기초자료로 제공하고자 한다.

외상성 고관절 탈구의 예후에 영향을 주는 요인

박찬상,조준,유병대,서영조,이명갑,이동필 대한응급의학회 1999 대한응급의학회지 Vol.10 No.4

Background : Incidence of traumatic hip dislocation have been increased with development of transportation. Traumatic hip dislocation demands early recognition as an emergency and prompt reduction. So we designed this study to determine what kinds of factors affect the prognosis of the patient. Methods ; Eighty five patients who admitted emergency department of our hospital with the traumatic hip dislocation were enrolled in this study. Cause of injury, type of dislocation, method of reduction, the time from dislocation to reduction, age, gender and associated patellar injury were evaluated by retrospective chart reviews. Results : Average age of excellent good group(E&G) is 28±17.8 and fair and poor group(F&P) is 39±18.6, so the older the age the more poor prognosis.(P<0.05). The time to take reduction of E&G group is 18±8.2 hours and F&P group is 25±12.6 hours, so the faster the better prognosis.(P<0.05) We classify the type of hip dislocation by Thompson and Epstein method, type Ⅰ to type Ⅴ. The prognosis of type Ⅰ is better than type Ⅴ(P<0.05). Fifty five case were associated with patellar injury and they had poor prognosis than the other cases that were not associated with knee joint injury. Conclusion : In traumatic dislocated hip patients, the prognosis was poor in old age, delay in reduction, higher type of dislocation and associated with knee joint injury.

DC 마그네트론 스퍼터링에 의한 알루미늄 박막의 증착과 그 특성

정귀상,조명찬 東西大學校 1996 동서논문집 Vol.2 No.1

This paper describes the physical, electrical and optical characteristics of Aluminum(AI) thin films deposited on corning glass substrate by DC magnetron sputtering. The AL thin films were investigated as variations of the input power, pressure and deposition time. The deposition rate was increased linearly as the input power increased. When Ar gas pressure was increased, the deposition rate was reduced. The maximum of deposition rate efficiency was obtained at 3 mtorr. The columnar growth and stable grain growth of AL thin films were observed through SEM on condition that the input power was increased and Ar gas pressure was decreased. The crystal qualities of AL thin films were also observed by XRD. In the XRD patterns, (111) oriented direction was only appeared at 38.5℃ The intensity of XRD peak was increased with increasing input power but decreased with increasing Ar gas pressure. The resistivity and Sheet resistivity were 4.85μΩ.cm and 0.052Ω/□, respectively, under input power(9W/㎠), pressure(7mtorr) and deposition time(10min). Depending on the input power, reflectance ranged from 84% to 94%. However, Ar gas pressure don't have influence on the reflectance. The maximum reflectance of the Al thin films was obtained at input power, 3W/㎠ and pressure, 3mtorr.

Siriraj Stroke Score 따른 뇌졸중 환자 감별의 적합성

유병대,이명갑,서영조,조준,박찬상,이동필 대한응급의학회 2000 대한응급의학회지 Vol.11 No.4

Background: The differentiation between hemorrhagic(HS) and norhemorrhagic(NHS) stroke is the most important first step in the management of acute stroke because clinical management of the two disorders differs substantially. Neuroimaging studies are useful in diagnosing and distinctioning between HS and NHS. The use of clinical variables, such as Siriraj stroke scores(SSS), has led to good sensitivity, specificity and predictive values. The aim of our study was to evaluate the use of the SSS in the Korean population and assess whether it could aid to expedite treatment decisions. Methods: We reviewed 111 cases of stroke patients admitted to our hospital via the emergency department over a 6 months period from July to December 1998. Levels of consciousness, vomiting, headache, and atheroma markers used in the SSS were applied to these patients who met the criteria for a stroke. Results: Of the 111 patients, the SSS classified 83 with sensitivities of 81.1%(NHS) and 73.3%(HS) and positive predictive values of 84.3% and 68.8%, respectively. The overall accuracy rate was 78.3%. Conclusion: Our results suggest that the SSS is not reliable in distinguishing stroke types in the Korean population. Definite neuroimaging studies are needed prior to thrombolytic therapy.

종이상자포장기의 개발에 관한 연구

권경우,권병철,류봉조,명태식,박찬호,이광원 한밭대학교 산업과학기술연구소 1994 논문집 Vol.2 No.-

The paper describes the development of a new automatic wrapping machine using paper films as it has not been used so far. The most of the automatic wrapping machine have used the vinyl film causing environmental pollution, the paper films, however, have a weak point in the aspect of high temperature adhesion. Therefore, the mechanism of the existing wrapping machine should be altered to prevent it from curling effect through the technical know-how. A new method and technology reducing the curling effect in the automnatic wrapping machine are demonstrated by using developed blower. Thus it is exqection and will decrease environmental pollution.

Potentiostatic Testing of Stress Resistance of PECVD Silicon Nitride Thin Film

Jo,Myung-Chan,Chung,Gwiy-Sang 東西大學校 1996 동서논문집 Vol.2 No.1

RECVD silicon nitride 박막의 thermal stress로 인한 cracking에 대한 저항을 전기화학적 방법으로 측정하였다. 두께가 약 0.5 micron인 박막이 4가지 다른 반응조건에서 0.9mm두께의 stainless steel 304 strip과 CERDIP test chip위에 증착되었다. 박막의 ultimate strain이 fourpoint bending 방법에 의하여 측정되었다. Cracking의 시작은 전기화학적 방법으로 검출하였다. 4가지 박막의 ultimate strain은 residual stress에 관계없이 모두 0.2%로 일정하였다. 박막의 residual stress가 thermal stress에 대한 저항에 어떻게 연관되어지는지를 조사하기 위하여 thermal shock and cycling test를 실시하였다. 시험후에 CERDIP test chip 위의 cracked bondpad수와 stainless steel substrate위의 박막에 형성된 crack을 통한 부식전류의 양을 측정하였다. 그 결과 좀 더 tensile stress를 받는 박막이 thermal stress로 인한 cracking에 대한 저항이 약하였다. Thermal stress-induced cracking resistance of Plasma-Enhanced Chemical Vapor Deposited(PECVD) silicon nitride thin film was investigated by potentiostatic method. Four different silicon nitride thin films in thicknesses of about 5kÅ were deposited on 0.9 mm thick stainless steel substrates and CERDIP test chips by varying deposition parameters. Ultimate strain of the film was measured by applying four-point bending to the substrate until the film went into tensile failure. The onset of cracking was detected by potentiostatic method. The ultimate strain of these films was constant at about 0.2% regardless of residual stress. Thermal shock and cycling test was conducted with the films on the substrate and the CERDIP chips. After the test, the number of cracked bondpads on the CERDIP test chip and corrosion current through the cracks of the films on the stainless steel substrate were measured. The results showed that more tensile films were more susceptible to crack-induced failure.

Reuse of Oyster Shell Waste as Antimicrobial Water Treatment Agent by Silver Ion Exchange

Jo, Myung-Chan,Byeong-II Noh,Shin, Choon-Hwan The Korean Environmental Sciences Society 2000 Environmental sciences Vol.4 No.3

A water treatment agent with antimicrobial activity(Ag-Os) was created by exchanging silver ion($Ag^{+}$) on calcined oyster shell powder. The desorption of the exchanged silver ion was negligible, thereby indicating a stable antimicrobial water treatment agent. The sterilization effect of Ag-Os on underwater microorganisms was then investigated. An MIC (Minimum Inhibitory Concentration) test result indicated that Ag-Os had an excellent sterilization effect on G-germs, such as Escherichia coli and Pseudomonas aeruginosa. Most germs were annihilated with an Ag-Os concentration of 200 ppm and contact time of 60 minutes. The sterilization effect was mainly dependent on the contact time. The zeta potential of the Ag-Os powder adsorbed on sand was measured relative to the concentration of exchanged silver ion. As the concentration of the exchanged silver ion increased, the surface charge density of the anions on the surface of the Ag-Os powder adsorbed on sand also increased. Accordingly, this result indicated that a higher silver ion than ion exchange capacity was present on the particle surface due to adsorption. Consequently, this increased concentration of exchanged silver ion would appear to significantly enhance the sterilization power.

A Study on the Feasibility of Silicon Nitride Thin Film as Diffusion Barriers over IC Chip Packaging

Myung-Chan Jo,Byeong-Il Noh 한국공업화학회 2002 Journal of Industrial and Engineering Chemistry Vol.8 No.5

INVESTIGATION OF FEEDPIPE BACKMIXING IN AN AGITATED VESSEL

Jo, Myung Chan,Song, Seung Hwan,Noh, Byeong Il,Kim, Jong Hyun 한국화학공학회 1996 Korean Journal of Chemical Engineering Vol.13 No.4

Feedpipe backmixing in an agitated vessel was investigated using a newly developed conductivity technique. By this technique, the onset of feedpipe backmixing could be detected and the penetration depth of the vessel fluid into a feedpipe was determined. For a given feedpipe flowrate. critical agitator speeds to eliminate feedpipe backmixing were determined using Rushton six-bladed disk turbine impeller (6BD) and high efficiency, axial-flow type 3-bladed impeller (HE-3) of 8.89 and 12.70 cm diameters in 11.2 liter reactor. The ratio of the feedpipe velocity to the critical agitator speed (v_f/v_t) was determined as a function of feedpipe Reynolds number (Na_(Ret)). The conductivity technique was successful either in the laminar regime, the transitional regime, or in the turbulent regime in the feedpipe.