Modified 9Cr-1Mo 강의 항온변태처리에 따른 미세조직 및 경도변화

유정훈,주성욱,허성강,신기삼,이수,정연길 국립7개대학공동논문집간행위원회 2003 공업기술연구 Vol.3 No.-

Evolution of microstructure and its relation with hardness in the modified 9%Cr-1%Mo steel which was isothermally heat-treated has been investigated in various heat-treatment temperatures and time of duration. For microstructural and crystallographic analyses, optical microscope, scanning and transmission electron microscopes, energy dispersive spectrometer, and X-ray diffractometer were used. Vickers microhardness tester were used for the measurement of hardness. Precipitates of the complex M23C6, M(C,N) formed at grain boundaries and interiors of grains had led to the secondary hardening. Normalized specimen and all of the isothermally heat-treated ones showed no evidence of retained austenite.

Al-Mg합금(Al-5wt%Mg-3wt%Zn-1wt%Mn)의 T6 열처리에 따른 미세조직 및 기계적 특성변화

유정훈,신기삼,허성강,김정민 국립7개대학공동논문집간행위원회 2005 공업기술연구 Vol.5 No.-

Al-Mg base alloys are attractive for aircraft. automobile and leisure applications because of their properties of low density, high intensity and wear resistance. The effect of Zn and Mn on the properties was studied in an Al-Mg base alloy. After T6 heat-treatment, the change of the microstructure and mechanical property was examined. Our investigations show that after T6 heat-treatment, the elongation was improved. The microstructures are investigated by TEM, which shows that the size of Al6Mn, Al57Mn12 phase is 100~500nm, and it also appears presence of the very small size MgZn₂ phase about 30nm.

Dissolved Air Flotation(DAF) 접촉조의 수리동력학적 조건이 입자의 제거에 미치는 영향

유제선,김성훈,신은허,박희경 대한상하수도학회 2003 상하수도학회지 Vol.17 No.1

Hydrodynamic conditions for optimum solids capture within the contact zone, which are governed by the geometry and flow, are not yet well understood. In this research, dimensionless parameters which represent hydrodynamic conditions in the contact zone were derived, using the Buckingham π theorem. Those parameters are Reynolds No. (Re), Froude No. (Fr), Weber No. (We), Local Weber No., and Bubble Capacity No. (Bc). The particle removal rate was investigated by changing each value of the dimensionless parameters. The experimental results indicate that particle removal rate, when gravity dominates and the flow is semi-turbulent (Fr < 0.3, Re < 8000), is higher than when inertia dominates and flow is turbulent. For the We, higher removal rates were obtained in the range of the We < 40. Relative to the Local We, smaller bubbles which are influenced more by surface tension than inertia, demonstrated a higher particle removal rate than larger bubbles. For the Bc, the optimal range is from 0.3 to 0.5. We suggest that these dimensionless parameters can be used to diagnose the performance of and to design a DAF reactor.

牛蒡子의 抗알러지 效果에 對한 硏究

兪漢鐵,金聖勳,金東熙 대한본초학회 2001 大韓本草學會誌 Vol.16 No.1

To evaluate the effectiveness of Arctii Fructus(AF) in the treatment of allergy, studies were done experimentally. The results were obtained as follows : 1. Cytotoxicity of AF extract on the mouse lung fibroblast cells was not shown below the level of 100 ㎍/㎖ concentration. 2. In the quantification of IL-1β gene development, the amount was decreased compared to control group, gut which was insignificant. 3. Gene development of IL-4 was suppressed over 70% in the concentration of 100㎍/㎖ and also the of production of IL-4 was decreased significantly in the concentration of 100㎍/㎖ compared to the control group. 4. Gene development of Il-5 was decreased to 60% in the concentration of 100 ㎍/㎖ compared to the control group. 5. Gene development of IL-4 and IL-10 were decreased compared to the control group, but which was not significant. 6. Gene development of TNF-α was suppressed over 60% in the concentration of 10 ㎍/㎖ compared to the control group. 7. The effect of suppression of IgE production was significantly decreased in the concentration of 100㎍/㎖. 8. The effect of suppression of Histamine release was decreased significantly in the concentration of 100 ㎍/㎖. According to the above results, AF has antiallergic effects and suppression of the immune response. Thus it is suggested that aqua extract of AF could be applied to the aqua-acupuncture for suppressing humoral immune response, and further research is recommended.

西歐 代替醫學의 癌 治療에 關한 硏究

兪和承,李容淵,徐祥熏,崔宇鎭,曺政孝,李淵月,孫彰奎,趙鍾寬 대한한방종양학회 2000 대한한방종양학회지 Vol.6 No.1

At here, we investigated the historical background, current stage, and concrete therapies of altematives in cancer therapy. We obatined the conclusion below. 1. Alternative medicine(AM) is a unothodoxial medical physiology, medical practice or intervension that overcome the side effects. faults, limits of coventional medicine. 2. Recentely, as emerging New-age movement, collgpse of Decarte's mecanical cosmology, and emphasis on patient rights, the interest of AM is increased, and foreign & domestic use rates of AM are risen. 3. After coventional medicine in cancer therapies tha depends on poerations, radiations, and chemotherapy is bounded, Altematives in cancer therapy are rapidly developed, and the majority of users are often considered satisfactory. 4. Alternatives in cancer therapy are classified six boundaries; Diet and Nutrition, MInd-body Technique, Integrated System, Pharmacologic and Biologictreatments, Immuno Enhanced Therapy, Immuno Enthaced Therapy, Natural and herbal medicine. 5. Looking at contents of Alternatives in cancer therapy, we get to know most of them are similar to the treatment of oriental medicine in holistic method, therapy, philosophy. If we synthesize the alternative medicine's treatment mentioned above and investigate it with oriental medical viewpoint, that may help us approach the conquest of cancer and improve the rate of cure. that may help us approach the conquest of cancer and improve the rate of cure. 6. It is certain that foreign AM will be imported reversely, and we must prepare for rebuilding of Korean traditional AM systemically, investing for activity positively, making national policy for medical system.

감나무애응애의 생활사와 화학적 방제

김상수,백채훈,유상선 順天大學校 1998 論文集 Vol.17 No.1

감나무애응애의 생활사를 27℃에서 조사한 결과, 난기간은 11.1일, 유충기간 6.9일, 전약충기간 5.6일, 후약충기간 8.0일이었다. 성충수명에서 산란전기간은 5.3일, 산란기간 18.3일, 산란후기간은 14.3일이었다. 평균 산란수는 15.4개, 성비는 1.2 : 1(암 : 수)이었다. 감나무애응애의 내적자연증가율은 0.0484, 개체군 배가기간은 14.3로 나타났다. 감나무애응애의 혼합태에 대한 약제효과 시험에서 azocyclotin 25WP, chinomethionat 25WP의 효과가 매우 우수하였으며, flufenoxuron 5DC, tetradifon+pirimiphosmethyl 33EC, hexythiazox 10WP, abamectin 1.8EC의 약효도 기대되었다. The life history of Tenuipalpus zhizhilashviliae was investigated at 27℃. The average durations of egg, larval, protonymphal and deutonymphal stages were 11.1 , 6.9, 5.6 and 8.0 days, respectively. The periods of preoviposition, oviposition and postoviposition were 5.3, 18.3 and 14.3 days, respectively. The average eggs laid by female was 15.4 and the sex-ratio was 1.2 : 1(female : male). The intrinsic rate of increase and population doubling time of Tenuipalpus zhizhilashviliae were 0.0484 and 14.3 days, respectively. As a result of chemical control, azocyclotin 25WP and chinomethionat 25WP were good effective against mixed developmental stages of Tenuipalpus zhizhilashviliae, followed by flufenoxuron 5DC, tetradifon+pirimiphosmethyl 33EC, hexythiazox 10WP, and abamectin 1.8EC.

Digital Imaging Fiber-Optic Trans-Illumination System 개발

이상민,김종수,유승훈 大韓小兒齒科學會 2009 大韓小兒齒科學會誌 Vol.36 No.2

본 연구는 기존의 DIFOTI™ 시스템의 문제점을 개선하고자 LED와 디지털 카메라를 결합한 발전된 형태의 prototype DIFOTI 시스템을 만들고, 이를 기존 시스템과 비교 평가하기 위하여 인공 우식 용액으로 탈회시킨 법랑질 시편에 대하여 1일부터 7일까지 영상을 촬영하고 분석하여 다음과 같은 결과를 얻었다. 1. 실험 기간에 따라 두 시스템 모두 우식 법랑질의 광투과도(index of transillumination)가 감소하는 양상을 보여 주었다. 2. DIFOTI™ 시스템에 비해 prototype DIFOTI 시스템에서 건전 법랑질과 탈회 법랑질 간의 발광도(intensity of luminance) 차이가 더 적게 나타나는 양상을 보였다. 이상의 결과를 종합해보면 prototype DIFOTI 시스템은 전류 소모량이 적은 LED를 사용하여 배터리를 사용한 무선 시스템으로의 개발 가능성을 보여 주었고, 디지털 카메라는 디지털 영상 기술의 발달과 함께 무선 전송 시에도 매우 높은 화질을 기대할 수 있어 차후에 보다 작고 사용이 편리한 DIFOTI 시스템을 개발할 수 있는 가능성이 크다 할 수 있다. This study was performed to improve the conventional DIFOTI™ system (EOS Inc., USA) by developing the prototype of DIFOTI system which consists of light emitting diode(LED) and digital camera. The images of enamel surfaces treated under Carbopol 907 de-mineralizing solution were taken daily during 7 days of experimental periods by both DIFOTI systems. The results of comparative analyses of obtained images can be summarized as follows: 1. Trans-illumination indices of images taken from sample enamel surfaces were decreased with time in both systems. 2. The difference of intensity of luminance between sound and de-mineralized enamel surface in prototype DIFOTI system was shown to be relatively smaller than conventional DIFOTI™ system. The application of LED light source in prototype DIFOTI system could possibly reduce the amount of current consumption and that could ultimately lead us to the successful development of wireless model with battery. The innovative development of digital camera is undoubtedly expected to create much clearer image despite of wireless transfer. LED and digital camera can be combined into a smaller size but a very important task of improving image manager and analyzing program into a simpler and easier one to manipulate has to be solved.

9-12%Cr강의 첨가원소 및 열처리에 따른 미세조직거동과 경도변화

주성욱,유정훈,신기삼,허성강,이재현,석진익,김병훈,김정태 국립7개대학공동논문집간행위원회 2004 공업기술연구 Vol.4 No.-

9-12%Cr steel are getting increasing attention for expanded application as high temperature materials applicable for gas turbine compressors, steam turbine rotors, blade and casing. For efficient and extensive application of 9-12%Cr steel, the data in addition to the improvement of mechanical properties on the correlation of microstructural evolution and mechanical properties are inevitable and thus the investigation in this study is performed for the determination for the specimens heat-treated at 600, 650 and 700℃ for 1000, 3000 and 5000hrs. The microstructure of as-received specimen was tempered martensite, with a high dislocation density and secondary phases. Upon high temperature heat-treatment, the martensite lath got larger and dislocation density decreased resulting the reduction of the strength. In addition, sharp growth of secondary phases was observed in the specimen heat-treated at 700℃ for 5000hrs. A specimen aged at 600℃ and 650℃ Laves phase was observed. The hardness showed close relationship with the secondary phase particle and dislocation density.

자궁내 태아발육지연 예측에 있어서 태아 Ponderal index의 임상적 의의

차상헌,유훈 순천향대학교 1986 논문집 Vol.9 No.3

The ponderal index describes the relationship between weight and crown-heel length of the neonate based on the equation: Neonatal ponderal index=weight/ length³×100. The ponderal index is a sensitive method to diagnose asymmetrically growth retarded infants. Until recently, calculation of ponderal indexes in the fetus has not been possible. With recent advances in the real-time ultrasound technology, it is possible to calculate the ponderal index in utero. The present study was designed to determine the relationship between the ultrasound fetal ponderal index and the neonatal ponderal index found at birth, and to evaluate the efficacy of the fetal ponderal index in predicting intrauterine growth retardation in infants with neonatal ponderal indexes below the tenth percentile for age. The results obtained were as follows: 1. There was no significant difference between the mean prenatal and postnatal values for weight, length, and ponderal index. 2. 15 of 125 cases(12%) had neonatal ponderal indexes below the tenth percentile for age at birth. Of these, 11 had also fetal ponderal indexes below the tenth percentile(sensitivity 73.3%). Of the 110 remaining infants with normal neonatal ponderal indexes, 87 had also normal fetal ponderal indexes(specificity 79.1%). 3. There were 33 infants with fetal ponderal indexes below the tenth percentile but 11 had neonatal ponderal index below the tenth percentile at birth(positive predictive value 33.3%). 4. Of the 92 with normal fetal ponderal indexes, 88 were also normal at birth(negative predictive value 95.7%). In conclusion, it is suggested that the calculated fetal ponderal index could be used to rule out fetal growth retardation with reasonable accuracy.

Flavobacterium meningosepticum에 의한 균혈증 1예

장성원,유진홍,진승원,김선우,김연식,박순민,이대훈,최민호,최주연,신완식,강문원,강지민 대한화학요법학회 1997 대한화학요법학회지 Vol.15 No.1

1996년 6월 카톨릭대학교 부천성가병원에 뇌경색으로 입원했던 61세 남자 환자의 혈액에서 Flavobacterium meningosepticum을 분리하였다. 환자는 폐렴을 동반한 패혈증의 예로 ceftriaxone과 metronidazole을 투여하였으나 입원 48시간만에 사망하였다. Flabovacterium meningosepticum is a rae cause of nosocomial infection which shows multi-drug resistance. It mainly invades patients with impaired immunity. Recently, we experienced a case of F. meningosepticum bacteremia in a patient with chronic debilitated state owing to stroke. The clinical progress was so rapid that he died within 48 hours. Blood culture revealed F. meningosepticum which showed characteristic yellow colony in blood agar plate.