STD 61종 금형강의 이온질화처리에 관한 연구(Ⅰ)

안병만,김용길,차병묵,피윤섭,윤재홍,김진관 國立 昌原大學校 産業技術硏究所 1994 産技硏論文集 Vol.8 No.-

STD61종 열간금형강의 수명향상을 위하여 ion nitriding처리를 실시하였다. 이온질화전의 모재의 열처리시에는 1030˚C에서 quenching한 후 530˚C에서 2시간 tempering했을 때 Hv=600의 높은 경도값을 나타내었다. 580˚C, 600˚C에서 2시간 tempering했을 때는 각각 Hv=500, Hv=400으로 경도값이 오히려 감소했다. 이온질화 처리시에는 처리시간이 길고 N₂와 Ar첨가유량이 많을 수록 깊은 화합물층과 확산층을 얻었다. 그리고 각 처리조건에서 안정된 Hv=1150의 질화물층을 얻을 수 있다. Ion nitriding treatment has been practiced to improve the life of hot die steel of STD61. Before nitriding the parent STD61 tempered at 530˚C, 2hrs after quenching at 1030˚C, It showed the high hardness distribution of Hv=600. The hardness distribution has decreased by Hv=400, Hv=500 when tempered for 2hrs at 580˚C, 600˚C. In the ion nitriding, the more treat-time and the more N₂and Ar flux, the deeper the compounded layer and the diffused layer. The stable hardness, Hv=1150, of nitride layer was obtained at various treatment condition.

축소 플랜트를 이용한 PID 제어기 설계

안두수,임윤식,김민형,이재춘,이한석 成均館大學校 科學技術硏究所 1995 論文集 Vol.46 No.1

In this paper, a simple method is developed for desiging a single loop PID contriller using a computer oriented algebraic approach which is based on general polynomial. Specifically, the proposed PID controller can approximately achieve an arbitrarily specified closed-loop response, which satisfies time domain specifications such as rising time, overshoot and settling time. The design technique is straightforward, and the paramaters of the PID controller are determined by solving a set of linear equations using the least squares method. It does not involve any trial and error proceduer, hence the difficulty of the conventional approach can be avoided.

톨루엔 디이소시아네이트 폭로 근로자들의 생물학적 모니터링

안연순,노재훈,김치년,박윤정,정상혁 大韓産業醫學會 1995 대한직업환경의학회지 Vol.7 No.2

Toluene diisocyanate(TDI) is widely used in the production of flexible polyurethane foams, as well as in the formulation of polyurethane paints and coatings. The commercial material is generally a mixture of 2,4- and 2, 6-TDI, the predominant mix being 80% 2,4 and 20% 2,6-TDI. The 2,4-isomer is considerably more reactive than the 2,6-TDI at ambient temperatures due to steric factors involving the positions of the isocyanate groups relative to the ring methyl group. Because of this difference in the reactivities of the isomers, it seemed probable that there might be an increase in the amount of 2,6-TDI offgased relative to the 2,4-isomer. Therefore a relative enrichment of the 2,6-TDI has been found in industrial atmospheres. Toluene diamines, which are metabolites of TDI, in urine have a linear relation with exposure to TDI, so that urianry TDA could be used as a biological index of the exposure to TDI. This study was conducted to investigate the distribution of TDI isomer in industrial atmospheres and to propose proper biological monitoring methods by identifying the relationships between the environmental TDI exposure and concentration of TDA in urine. Concentrations of 2, 4-TDI and 2, 6-TDI in air were 4.38㎍/㎥ and 25.43㎍/㎥, respectively. The Threshold Limited Value of 40㎍/㎥ was exceeded for the 2, 6-TDI in about 46.8%(22 samples) of the samples, while the 2, 4-TDI was not at all exceeded. The ratio between 2, 4-TDI and 2, 6-TDI varied in air samples in the range of 2.4%:97.6%-51.0%:49.0%. There was an enrichment of 2, 6-TDI in air relative to the 2, 4-TDI. Concentrations of 2, 4-TDA and 2, 6-TDA in urine were 1.31㎍/g creatinine and 4.16㎍/g creatinine, respectively. The ratio between 2, 4-TDA and 2, 6-TDA varied in urine samples in the range of 1.4%:98.6%-99.9%:0.1%. There was an enrichment of 2, 6-TDA in urine relative to the 2, 4-TDA. No relation between the concerations of TDA isomer in urine and concerations of TDI isomer in air was found. Above results of this study, workers were more exposed to the 2, 6-TDI relative to the 2, 4-TDI in industrial atmospheres. Therefore, the establishment of TLV for 2, 6-TDI should be considered. Also, the further studies on biological monitorigs of workers exposed to TDI should be continued.

랫드 배양배아에서 ginsenosides가 superoxide dismutase 유전자 발현에 미치는 영향

김재승, 이세라, 김연, 연정민, 백인정, 안병우, 김윤배, 이범준, 윤영원, 남상윤 충북대학교 동물의학연구소 2006 Journal of Biomedical and Translational Research Vol.7 No.2

본문참고

보육시설 교사를 대상으로 하는 환경교육 프로그램의 개발

안지연,윤재웅,안옥희 영남대학교 지역발전연구소 1999 새마을지역개발연구 Vol.25 No.-

It is very important for preschool child to environment education in child care and education institution. However only few studies concerned to concrete education program. Therefore this study was environment education program for teacher in child care and education institution. Environment education program were consist of four steps; general idea of environment education, component abstract of environment education program for child, give motivation with development to environment education program, application of environment education program.

강관지주의 구조성능 평가에 관한 실험적 연구

이재연,안용선,윤현도,김성수 牧園大學校 建築·都市硏究센터 1998 建築·都市環境硏究 Vol.6 No.-

This paper describes the test procedures and results on the estimation of structural performance of temporary pipe supports being used in most construction fields. In order to propose the limit eccentricity of pipe supports for structural safety, 46 specimens were tested with the parameters of support lengths, eccentricities, and support end conditions. From the test results, it is found that the limit eccentricity of the supports is 1.0D, where D is outer diameter of the supports.

수증기 개질반응용 니켈촉매에 첨가된 리튬의 효과

최재석,윤정숙,임태훈,홍성안,이호인 한국공업화학회 2005 응용화학 Vol.9 No.1

In the direct internal reforming type molten carbonate fuel cell, alkali carbonates used as electrolyte in the cell are transported to reforming catalyst of which activity drastically decreases. In our previous work, the deactivation of the nickel catalyst was studied with increasing the amount of added lithium. Unexpectedly, the increase of activity was observed with a small amount of lithium less than 1wt%. The results of TPR, XRD and chemisorption showed no significant difference between the fresh catalyst and the Li-added one, implying that lithium did not cause the change of morphological property of the supported nickel. To elucidate the effect of lithium the methanation of CO was applied to the catalysts, which was considered as the reverse reaction of the key elementary step of methane steam reforming. It can be seen by an online mass spectrometer that the small injection of CO/H₂ mixture into the Li-added catalyst reactor at 650 ℃ showed the longer tail of produced methane than into the fresh one. The delay should be originated from the effect of lithium, which determined the overall rate on the Li-added catalyst.

강관지주의 구조성능 평가에 관한 연구 : Field Surveys on the Use of Temporary Pipe Supports 강관지주의 운용에 관한 현장조사를 중심으로

이재연,안용선,김성수,윤승조,윤현도 牧園大學校 建築·都市硏究센터 1997 建築·都市環境硏究 Vol.5 No.-

This paper describes the procedures and results of field surveys on the use of temporary pipe supports as a preliminary research on the estimation of structural performance of the supports. Question surveys and measuring surveys for the supports were performed in 25 construction fields. From the field survey results, the problems and improvement methods in the use of the supports were presented, and the experiment data for the estimation of structural performance of the supports were accumulated.

소재 관련업체 및 기관과 신소재연구소의 상호 정보교환 시스템 구축

박재윤,안영철,전병세 경남대학교 신소재연구소 2002 신소재연구 Vol.14 No.-

현재 국내 부품소재 산업은 제조업 총 생산액의 약 30%를 차지하는 주요산업이며, 향후 그 규모가 확대될 전망이다. 그러나, 산학간의 관계에 있어서는 상대방에 대한 정보가 제한되어 있기 때문에 중소기업의 애로기술을 해결하기 위한 산학협동이 어려운 실정이다. 따라서 경남대학교 신소재연구소에서는 산학간의 정보교환을 원활하게 하고 중소기업의 애로기술을 해결하고자 부품소재관련 전문 홈페이지를 구축하였다. 본 연구에서는 중소기업 및 경남대학교의 구성원이 신소재연구소의 홈페이지를 쉽게 사용할 수 있도록 홈페이지의 내용을 설명하고자 한다. Currently, parts and materials industry is the major part of the domestic manufacturing industry occupying 30% of the market and the share is expected to increasingly grow. However, as far as the relationship between the industry and the university is concerned, it is very difficult to develop an industry-university cooperation to solve a technological difficulties of the medium and small sized enterprises because of the limited amount of informations between them. Therefore, a homepage for parts and materials has been constructed in the Institute for Advanced Materials in Kyungnam University to facilitate free exchange of informations between industry and university and to solve technological difficulties of the industry. In this study, the contents of the homepage are introduced in detail for the users in the medium and small sized enterprises and Kyungnam University.

Lipopolysaccharide 로 유발된 생쥐 무릎관절낭 염증에 관한 형태학적 연구 : 윤활관절막과 섬유관절막의 변화를 중심으로 Based on the Morphological Changes of Synovial Membrane and Fibrous Membrane

김진택,안상현,최난희,정재만,박인식,강윤호,김호현,이해풍 동국대학교 한의학연구소 1999 東國韓醫學硏究所論文集 Vol.7 No.2

본 연구는 관절염 유발시 일어나는 관절낭의 형태학적 변화를 조사하기위해 ljpopolysaccharide(LPS)주사로 인위적 관절낭 염증을 유발시킨 후 시간경과에 따른 윤활관절막과 섬유관절막의 형태 변화를 관찰하였다. BALB/C 암컷 생쥐 오른쪽 무릎관절낭에 LPS 300㎍/㎏를 주사한 후 3, 7 그리고 14일에 무릎관절을 얻었다. 무릎관절은 4주동안 EDTA용액에 탈회한 후 통상적 방법으로 paraffin에 포매하였다. 또한 윤활관절막의 미세구조변화는 embed812로 포매한 후 관찰하였다. LPS 주사후 관절연골 인접부위의 윤활관절막에서 시작된 세포과형성(hyperplasia)은 시간 경과후 전체 윤활관절막으로 확대되었다. 윤활관절막내의 미세구조의 변화로는 윤활포식세포(type 1)가 관절강내로의 많은 돌기(filopodia)를 내었고, 잘 발달된 과립형질내세망을 가지는 type 2 윤활분비세포의 숫적 증가가 보였다. 한편 LPS 주사후 섬유관절막에서 나타나는 형태학적 변화는 collagen fiber 생성에 의한 섬유화가 증가되며, 이러한 섬유화를 주도하는 섬유모세포의 이주증가파 관찰되었다. 또한 혈관 주위에서는 백혈구의 이주 증가가 나타났으며, 탈과립형(degranulated type) 비만세포가 많이 관찰되었다. 이상의 결과로 LPS 주사로 관절낭에서 염증이 유발되어 윤활관전막과 섬유관절막에서 형태학적 변화가 나타났다. 이러한 일련의 형태학적 변화는 발병초기 류마티스성 관절염에서 나타나는 병리학적 소건과 동일한 결과로서, 앞으로 진행될 치료제 개발과 유발기전에 관한 해석을 위한 in vivo 실험의 적절한 모델로 기여한 것으로 기대된다. Synovial joint of BALB/C mice were injeced with Lipopolysaccharide(LPS) were observed to investigate the morphological changes of synovial capsule caused by rheumatoid arthritis(RA). The RA on female Balb/c mice were induced by LPS injection, as dose of 300㎍/㎏, into synovial cavity of knee joint. And then these specimen were fixed in 10% neutral buffered formalin and were decalcificated in EDTA solution for 4 weeks. The hyperplasia of synovium were appeared in synovial membrane. The filopodia of phagocytic like synoviocyte(type Ⅰ synoviocyte) projected into synovial cavity and the number of fibroblast like synoviocyte(type Ⅱ synoviocyte) with well-developed endoplasmic reticulum were increased in synovium. In fibrous membrane, the fibrosis induced by synthesis of collagen fiber were enlarged to all fibrous membrane, and the number of fibroblast were increased. A great number of inflammation component cell as Iymphocyte and neutrophil leukocyte were infiltrated around capillary and the degranulate typed mast cell were increased. As results indicated that the hyperplasia of synovium induced by LPS, subsequently to cause the fibrosis, infiltration of imflammation component cell, and increase of degranulated type mast call as same as symptoms of RA.