[우리가정 이야기] 사진찍기ㆍ메모판쓰기로 단란한 분위기를

한진구 새가정사 1993 새가정 Vol.- No.-

마이크로파 전처리법을 이용한 요중연의 분석

노영만,한진구 가톨릭대학산업의학센타 산업의학연구소 1996 韓國의 産業醫學 Vol.35 No.4

요중연 농도는 혈중연에 비하여 10배 정도 낮아 이로 인해 요중연 분석시 어려움이 많고, 특히 요중에 함유되어 있는 방해물질의 영향이 크다. 또한 하루정도 시간이 경과한 뇨는 침전물이 생기게 되어 분석시의 어려운점이 많아 본 연구에서는 마이크로파 전처리법(MW)을 이용하여 기존방법(non-MW)과의 차이를 비교하고, 표준뇨(NIST, SRM 2670)를 사용하여 마이크로파 전처리법의 정확도를 산출하였고 표준뇨를 제조하여 분석의 정밀도 및 저장기간에 다른 시료의 재현성을 조사하여 우리나라의 생체시료 정도관리 및 연 특수검진시 분석의 정확도와 정밀도를 향상시킬 수 있는 분석방법을 제시하고자 하였다. 그 결과는 다음과 같다. 1. 표준뇨(SRM)을 MW로 처리한 뇨의 농도는 저농도가 23.1±1.6㎍/1 이고 고농도가 105.0±4.6㎍/1로 고농도 측정치가 기준값에 근접하는 수치를 보였고, 저농도와 고농도에서 모두 MW뇨와 non-MW뇨 사이에 통계적으로 유의한 차이가 있었다. 2. 표준뇨를 3가지 농도로 제작하여 전처리 방법에 따른 회수율의 차이를 보았는데 non-MW뇨의 회수율은 85.5%이었고 MW뇨의 경우는 101.56%이었으며 고농도 MW뇨의 경우 표준편차는 4.6㎍/1로 표준뇨(SRM)의 기준값고 근접하는 범위내에 들었다. 3. 제작한 표준뇨의 각농도에서 저장기간에 따른 요중연 농도변화를 보았는데 두 전처리 방법이 저장기간에 따른 변화양상이 동일하고 유의하게 감소하고 있었으며 또한 두 전처리 방법간에 있어 농도간의 차이가 있었다. 4. MW 방법으로 분석한 정상인의 요중연 농도는 남성이 33±7.8㎍/1이고 여성은 31.9±6.5㎍/1 이었다. 이상의 결과로 볼 때 마이크로파 전처리법을 이용한 요중연농도 분석법은 분석의 정확도와 정밀도가 우수하였고, 시료의 저장기간에 따른 농도의 변화도 적어 연노출근로자의 특수검진 및 생물학적 노출지표를 측정하기 위한 유용한 방법으로 이용될 수 있을 것이다. Two digestion methods of urine, the traditional (non-MW) and the microwave (MW) methods, were compared in order to improve the accuracy and precision of lead in urine analysis. The accuracy and precision of the MW method was determined with the standard reference material prepared by NIST and the urine samples prepared by our laboratory. The effect of storage condition on lead level in urine was determined by analyzing samples at three day interval for three weeks. 1. The mean leak concentrations of the NIST samples containing low level of lead treated with MW and with non-MW were 23.1?1.6 and 31.0?3.8?/1,respectively. A statistically significantly higher lead concentration was found in the non-MW method. For the NIST samples containing high level of urine, the mean lead conenbtration in urine treated with MW was 105.0?406 while that with noMW was 129.0?0.5?/1. The accuracy of the MW method which was compared with the NIST reference levels was better than that of the non-MW method. 2. The mean of recovery rate of MW in urine spiked lead at three levels were higher than that in non-MW. 3. The changes of concentrations in urine added known amounts at three levels reduced to show same tendency in MW and non-MW, but there was a significant difference between them. 4.The mean of lead level with MW in no previous occupational exposure in lead were 33?708?/1 for male and 31.9?6.5?/1 for female. The results obtained in this study shows that the MW digestion method is capable of improving the accuracy and precision of measuring lead levels in urine. Therefore, it is recommended to use the method when analyzing urine samples for lead determination.

주조 상태 및 용체화처리한 AZ91-4%RE 마그네슘 합금의 부식 거동

한진구 ( Jin-gu Han ),현승균 ( Soong-keun Hyun ),전중환 ( Joong-hwan Jun ) 한국열처리공학회 2018 熱處理工學會誌 Vol.31 No.5

The objective of this study is to investigate the effect of solution treatment on the microstructure and corrosion behavior of cast AZ91-4%RE magnesium alloy. In the as-cast state, microstructure of the AZ91-4%RE alloy was characterized by intermetallic β(Mg₁₇Al₁₂), Al₁₁RE₃ and Al2RE phase particles distributed in α-(Mg) matrix. After solution treatment, the β particles with low melting point dissolved into the matrix, but Al-RE phases still remained due to their high thermal stabilities. It was found from the immersion and potentiodynamic polarization tests that corrosion rate of the AZ91-4%RE alloy increased after the solution treatment. On the contrary, EIS tests and EDS compositional analyses on the surface corrosion products indicated that the stability of the corrosion product was improved after the solution treatment. Examinations on the corroded microstructures for the ascast and solution-treated samples revealed that dissolution of the β particles which play a beneficial role in suppressing corrosion propagation, would be responsible for the deterioration of corrosion resistance after the solution treatment. This result implies that the microstructural features such as amount, size and distribution of secondary phases that determine corrosion mechanism, are more influential on the corrosion rate in comparison with the stability of surface corrosion product. (Received August 7, 2018; Revised August 31, 2018; Accepted September 6, 2018)

Mg-4%Zn 주조 합금의 부식 거동에 미치는 Sn 첨가의 영향

한진구 ( Jin-gu Han ),전중환 ( Joong-hwan Jun ) 한국주조공학회 2017 한국주조공학회지 Vol.37 No.3

In the present study, effects of an addition of Sn on the microstructure and corrosion behavior were investigated in Mg-4%Zn-(0-3)%Sn casting alloys. With an increase in the Sn content, the α-(Mg) dendritic cell size was reduced, whereas the total amount of precipitates increased due to the formation of the Mg₂Sn phase. It was found in immersion and electrochemical corrosion tests that the addition of Sn has a detrimental effect on the corrosion resistance of the Mg-4%Zn alloy. Microstructural examinations of the corrosion product and the corroded surface indicated that an accelerated micro-galvanic effect by the Mg₂Sn-phase particles and a less protective corrosion product on the surface were responsible for the increased corrosion rate at a higher Sn content.

Mg-Al 합금에서 등온 시효 중 경도 변화의 미세조직 의존성

한진구 ( Jin-gu Han ),전중환 ( Joong-hwan Jun ) 한국열처리공학회 2019 熱處理工學會誌 Vol.32 No.6

This study is intended to clarify the main microstructural factors that contribute to an increase of hardness during isothermal aging in Mg-Al alloy. For this work, Mg-9.3%Al alloy specimens were solution-treated at 688 K for 24 h followed by water quenching, and then aged at 473 K for up to 24 h. The aging at 473 K yielded nodular discontinuous precipitates (DPs) with (α+β) lamellar morphology at the grain boundaries, and the volume fraction of DPs increased from 0% to ~30% with increasing aging time up to 12 h. For the aging times longer than 12 h, further formation of DPs was substantially inhibited owing to the occurrence of significant continuous precipitation within the α-(Mg) matrix, and the density of continuous precipitates (CPs) becomes greater with increasing aging time. Hardness of the specimen was steadily increased with aging time up to 24 h. Microstructural examination on the aged specimens revealed that the increased overall hardness at the early stage of aging is associated with the increased volume fraction of DPs, but at the later stage of aging, where the amount of DPs was hardly changed, the increased hardness of the α-(Mg) matrix in response to the higher density of CPs within the matrix, plays a key role in increasing the overall hardness value. (Received October 14, 2019; Revised October 25, 2019; Accepted November 1, 2019)

생물학적 노출지표 검사의 의학적 효용성 고찰 및 기준 제안 (pp.176-184)

김형렬,한진구,홍정연,박용선 대한직업환경의학회 2010 대한직업환경의학회 학술대회 논문집 Vol.45 No.-

敎育大學 藝體能 敎育課程 改善 方案의 硏究 : 國民學校 藝體能 敎科擔任敎師 養成을 中心으로 With Special Reference to the Training of the Teachers in Charge of Arts and Physical Education of the Elementary Schools

成義鏞,韓進九,朱完珣 春川敎育大學 1977 論文集 Vol.17 No.-

RAW 264.7 세포에 대한 중국산 천연 광물성 섬유 TAFMAG의 독성효과

임영,한진구,김지홍,김현욱,김은경,김경아,장황신 大韓産業醫學會 1999 대한직업환경의학회지 Vol.11 No.3

Objectives : This study was designed to evaluate cytotoxicity of TAFMAG, which is a trade name of natural mineral fiber mined and produced in China. Methods : The cytotoxicity of TAFMAG was evaluated by measuring iron content, lipid peroxidation, erythrocyte hemolysis, and cytotoxicity in vitro. These results were compared with the data of chrystotile and wollastonite as a positive and negative control, respectively. Results : There was significant increase of Fenton activity in TAFMAG and chrysotile with dose-response pattern. The iron chelating agent, desferrioxamine, significantly decreased Fenton activity of the particulates except wollastonite. TAFMAG and chrysotile fibers significantly increased malondialdehyde concentration from lipid peroxidation of the red blood cell membrane. In erythrocyte hemolysis test, TAFMAG & chrysotile had stronger effect on erythrocyte hemolysis than wollastonite with the concentration of 1,000g/ml. Furthermore, TAFMAG was more hemolytic than chrysotile with the concentration of 5,000g/ml. There was a significant cytotoxic effect in TAFMAG and chrysotile on RAW cell compared with wollastonite. Conclusions : In vitro study suggested that TAFMAG may have a similar health hazard as usual asbestos.

兒童의 造形能力(繪畵, 彫塑)과 他 敎科成積과의 相關에 關한 硏究

金正熹,韓進九,李吉鍾,金相俊 春川敎育大學 1985 論文集 Vol.25 No.-

The main purpose of this sutdy is ultimately to help improve art education by clarifying and interpreting the correlation of modeling ability to that of other subjects taught in primary schools. This research covered a total of 600 children of two schools : one in Chunchon city and the other in Chunsong county. As the marks of all the subjects are scaled by the absolute achievement evaluation method, the average of the tatal subjects showed a high mark of 4.23. But our research team, having measured their modeling ability in relative evaluation method, marked only 3.31 point in average. Notwithstanding this discrepancy, the correlation between the marks of the toal subjects and the drawing revealed a strikingly low coefficient of 0. 18 and 0.23 between the total and sculpturing ; and 0.20 between the tatal and modeling as a whole. Thus, it is definite that any argument for high correlation among achievements in subjects cannot apply to art subject. The result of this research may be revised by drawing data from markings of identical evaluation method, but the difference will be of little consequence.

89하계지표조사보고 : 예천 호명면

박정숙,한진구,임정옥 안동대학 안동사연구회 1989 安東史硏究 Vol.3 No.1

작년 예천군 지보면 지역에 이어 올해는 예천군 호명면 지역을 조사하였다. 조금은 안동에서 먼 지역이고 해서 걱정이 되었지만 조사원 전체의 노력으로 큰 사고 없이 끝이 났다. 곳곳의 사정에 의해, 혹은 우천으로 인한 일정의 많은 변화를 겪었고, 미지의 지역인 탓에 여러가지 어려움도 겪었다. 산세를 모르고, 지역사정을 확실히 모르고 해서 부득이 하게 계획을 바꾸어야만 했다. 이제 3박4일간이 일정이 끝난 지금, 조사내용을 간략하게 소개하고자 한다. 지표조사는 6월 26일 활발하고 의지 있는 분위기 속에서 시작되었다.