Effect of Electrochemical Hydrogen Charging Time on Hydrogen Embrittlement of the Hot-Rolled and Accelerated Cooling Treated API X70 Steel

Dong‑Su Bae,Un‑Bong Baek,Seung‑Hoon Nahm,Ilguk Jo 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.2

This study investigated the effect of the hydrogen charging time on the hydrogen embrittlement of hot-rolled and acceleratedcoolingtreated API X70 steel by using the electrochemical hydrogen charging method. Tensile and V-notch Charpy impacttest were completed for the specimens of hydrogen charged for 0, 2, 4, and 10 h, and then microstructural observation wereperformed. The tensile and yield strength tended to decrease slightly and the total elongation started to decrease rapidly up to2 h charging time and then these gradually decreased with the hydrogen charging time. The post-uniform elongation increasedslightly after the holding time of 2 h due to the occurrence of two-step stress reduction phenomenon and its mechanismhas suggested. The effect of the hydrogen embrittlement on impact absorption energy according to the hydrogen chargingtime were also investigated. The fracture surface of the hydrogen charged ones are generally composed of cleavage fracturesurfaces. It was demonstrated that the external cracks were formed on the outside of tensile tested specimen and the externalshape of the fracture portion was fractured without large elongation at hydrogen charged specimens.

동의보감 탕액편에 기재된 식이본초의 독성유무에 대한 분류 연구

신호동(Ho-Dong Shin),정종운(Jong-Un Jeong) 대한한의학회 2011 대한한의학회지 Vol.32 No.1

최근 10년간 발생한 신손상 분석

최동은, 김원태, 김용준, 윤석중, 이상철, 김원재 충북대학교 의과대학 충북대학교 의학연구소 2012 忠北醫大學術誌 Vol.22 No.1

연구목적: 신손상은 보통 복부외상 환자의 10% 정도에서 발생하며 비뇨기계에서 발생하는 손상 중 가장 높은 빈도를 차지하고 있다. 신손상 치료의 궁극적인 목표가 환자의 생명을 구하는 것이고, 가능 하면 신조직을 최대한 보존하면서도 합병증은 최소화하여야 하므로 정확하게 평가된 진단을 내려, 혈류 역학적으로 안정된 경우 보존적 요법을 시행하는 빈도는 증가하고 있다. 본 연구에서는 10년간의 신손 상을 분석하여 손상의 원인, 정도, 치료 방법 등을 알아보고자 하였다. 대상및방법: 2000년 2월부터 2010년 6월까지 본원 응급실에 방문하여 신손상으로 진단된 59명의 환 자들을 후향적으로 분석하였다. 결과: 환자의 성별은 남자가 39례 (66.1%)였고, 여자가 20례 (33.9%)였다. 신손상의 원인은 교통 사고가 37례 (62.7%)였고, 낙상이 7례 (11.9%), 외상이 12례 (20.3%), 자상이 1례 (1.7%), 원 인미상이 2례 (3.4% )였다. 손상의 정도는 I 등급이 11례 (18.6%), II 등급이 10례 (16.9%), III 등급이 20례 (33.9%), IV 등급이 10례 (16.9%), V 등급이 8례 (13.6%)였다. 신손상 환자의 치료 는 대증치료가 46례 (77.9%)였고, 신절제술이 5례 (8.5%), 신혈관색전술이 5례 (8,5%), 그외 다른 치료들이 3례 (5.1%)였다. 결론: 신손상의 원인은 교통사고와 외상 등이 가장 많은 비중을 차지했으며, 3 등급의 손상이 가장 많 았고, 치료는 대증요법이 주를 이루었지만, 점차 신혈관색전술이 늘어나고 있다. 앞으로 지역단위로의 추가적인 연구가 필요할 것으로 생각된다.

단국대의 교수 임금체계

박동운 단국대학교 1996 論文集 Vol.30 No.-

The wage system is a word being used in relation to the composition items and determination criteria of wages. It is important that the wage system should be reasonable in any case. It is known that the professor wage system of Dankook University is unreasonable. The purpose of this study is to point out the problems of the professor wage system of Dankook University and to show the measures to improve it, on the theoretical basis. This paper is composed of five chapters. The findings of this study are as follow. First, there are 7 kinds of pay schedule at Dankook University, which may not be found in other universities. The pay schedule of Dankook university can be reduced to 3∼4 kinds. Second, there are 21 wage items at Dankook University, which also cannot be found in other universities. The wage items of Dankook University can be reduced to about 5 items. Third, the professor wage system of Dankook University is a kind of seniority system. We recommend that this kind of wage system include profit-based system. Fourth, the rate and amount of increse in wages in pay step of the professor wage system of Dankook University is unreasonable. Fifth, we cannot find any reasonable rules applied to the determination of pay step indices in the professor wage system of Dankook University. It may be expressed as 'low-generous but high-generous but high-mean'system. About 1.7 billion wons are needed to improve the current unreasonable professor wage system, which takes about 4% of the total labor costs of Dankook University.

퍼지추론을 이용한 비선형성 해석 및 자동동조의 구현

이은철,이동진,변황우 건국대학교 1994 대학원 학술논문집 Vol.38 No.-

This paper presents a new identification method which utilizes fuzzy inference in parameter identification. The proposed system has an additional control loop where a real plant is replaced by a plant model. The control system to be designed is to satisfy the following specifications: 1) It has zero steady-state error. 2) It has adequate damping characteristics. 3) 1), 2) satisfied, it has a shortest rise-time, Fuzzy rules describe the relationship between comparison results of the features and magnitude of modification in the model parameter values. This method is effective in auto-tuning because the response of the closed loop is verified. The proposed method is tested in simulation for several plants with high-order lags and dead-times.

다수의 냉동시스템에 의한 저온 저장고의 에너지 성능평가

강동언,김성만,운종호,이의준,박영하,현명택 濟州大學校 産業技術硏究所 2000 산업기술연구소논문집 Vol.11 No.1

The cool storage system(CSS) is a specific building that is required only cooling load without heating during the whole year. CSS uses a electric energy which is very expensive and is required much amount of energy due to temperature differences between interior and ambient temperatures. The purpose of this study is to assess the energy performance of the multi-unit cooler operating control system. For the prediction of its performance, two types of test (KIER). First cell is equiped with one .are installed a t Korea Institute of Energy Research large unit cooler. and second cell consists of two small unit coolers. According to the results of experiments using these cells. the multi-unit cooler operating control system is found to be effective in energy saving and beneficial for storage due to much less deviation of temperature.

政府部門의 膨脹과 인플레이션

朴東雲 단국대학교 1983 論文集 Vol.17 No.-

It is well known that inflation is one of the most serious problems in the capitalist economic system. Many competing economic theories have been tested with respect to the determinants of inflation, which are fully surveyed by M. Bronfenbrenner―F. Holzman, D. Laidler-M. Parkin, R. Gordon and H. Frish. However, a new approach to inflation in which government is a prime mover has been recently developed by the leading economists such as M. Friedman and J. Buchanan. The purpose of this study is to summarize this new view and apply it to the case of Korea. The main findings are as follows. (1) Many capitalist countries are facing with stagflation or slumpflation. (2) Leading economists such as J. Buchanan and M. Friedman criticize that inflation in the capitalist countries ise induced by government itself. (3) The source of the expansion of government sector, relatively and absoultely, can be found in the economic theory of J. Keynes, who proposed a deficit financing fiscal policy to stabilize the economy during the recession period. (4) In many countries governments utilize a deficit financing fiscal policy for the political purpose by financing budget deficits from bank loans. As a result, money supply will be excessive and inflation will occur, according to the montarist view. (5) One example of this fact can be found in many advanced capitalist countries. (6) The same fact is found in the case of Korea. (7) It is recognized that the only way to control inflation in capitalist countries is to adopt balanced-budget rule. For that purpose, the enactment of the fiscal-monetary constitution is proposed as the most convincing one. (8) Korea has experienced a serious inflation problem during the last two decades, even though she recorded the highest rate of economic growth in the world. Therefore, balanced-budget rule should be adopted to control inflation. Fortunately, the Korean government since 1980's has endeavored to tighten the government expenditure.

지역간 경제력 격차 분석

朴東雲 단국대학교 산업연구소 1989 산업연구 Vol.12 No.-

日本腦炎患者의 豫後 및 後遺症에 關한 疫學的 調査硏究

李棟培,深雲澤 충남대학교 의과대학 지역사회의학연구소 1984 충남의대잡지 Vol.11 No.1

This study was designed to find out the epidemiological features and factors influenced on the prognosis and sequelae of Japanese encephalitis on 333 patients, reported to the Health Centers in Chungnam, in 1982. The survey was conducted from June 20, 1983 through September 20, 1983. Followings are the results therefrom. 1. Among the total patients, 62.2 percent were male, 37.8 percent were female. The ratio of male to female was 1.64 to 1. 2. Main epidemic period of the outbreak was one month from the middle part of August to that of September in the year. Unvaccinated patients formed 85.3 percent and completely vaccinated 4. 5 percent. Serologically confirmed patietns formed 60. 4 percent. 3. As for the prognosis, the follow: death 13.8 percent, sequelae 49.2 percent, and complete cure 36.9 percent, the rate of sequelae after 1 year was 36.6 percent, and Japanese encephalitis sequlae of 28.4 percent disappeared within a year. 4. The main sequelae of Japanese encephalitis, during the outbreak were cognitive function impairment with 69.5 percent, motor paralysis with 45.7 percent, personality change with 44.5 percent, tremor with 35.4 percent, parkinsonism with 20. 7 percent and, choreoathetosis with 16. 4 percent. After one year, the rates of the main sequelae of Japanese encephalitis were cognitive function impairment with 63. 1 percent, personality change with 49. 1 percent, motor paralysis with 30.3 percent, tremor with 18.9 percent, parkinsonism with 12.3 percent, choreoathetosis with 10.7 percent. 5. Average duration of transient sequeae was 2.1 months, t7.5 percent of them disappeared within 6 months. 6. The prognosis of Japanese encephalitis patients have nothing to do with age and sex, types of medical facility treated and occured month. But geographical distribution, vaccination status, level of consciousness, duration of hospitalization, result of HI-test were revealed to be influencing factors to the Japanese encephalitis prognosis.

한국 재래산양에서 Bovine Viral Diarrhea, Bovine Herpesvirus-1, Parainfluenza Type-3 바이러스에 대한 혈청학적 연구

한동운,권용국,문진산,윤소라,위성환,장환,탁동섭,이태욱,강문일 한국수의공중보건학회 2003 예방수의학회지 Vol.27 No.3

The 948 goat sera were serologically tested for ten pathogens including bovine viral diarrhea (BVD), bovine herpes virus type-1 (BHV-1) and parainfluenza virus type-3 (PI-3). By viral neutralizaion test, three pathogens including BVD virus, BHV-1, PI-3 were applied for screening each neutralizing antibody and its titration. Among 948 sera, there were 215 seropositives (22.7%) against BVD virus, 25 (2.6%) against BHV-1 virus, and 161 (17.0%) against PI-3 virus, respectively. In the seropositive cases to BVD virus, provincial prevalence of them were recorded as Gyeongnam(30.8%) for the highest one, while as Jeonbuk (15.8%) and Gyeongbuk(l6.7%) relatively for the lower ones. Among them, higher than 1:8 in antibody titration was classified as 74 cases (34.4%) which were suspected the cycle of its infection in their herds. Among the seropositives to BHV-1, it was relatively lower prevalence rate ranging from 1.7% to 6.7% that those of BVD virus and PI-3, but more importantly they were prevailing across the country. Most of the seropositive cases (42.9%) to PI-3 were classified as 1:4-1:16 in titration, but also distributed all around the country. The prevalence in goats varied according to areas (15.8 to 30.8%). Related to the provincial prevalence of three viral agents in Korean goats, it seemed that three viral pathogens would be directly or indirectly involving in various disorders as primary or secondary causative agents resulting in decreased productivity.