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.

미국 민속학에서 물질문화에 대한 인식과 연구

배영동(Bae, Young-Dong) 비교민속학회 2014 비교민속학 Vol.0 No.55

여러 나라 민속학 연구에서 물질문화(material culture)는 후발 주자로 성립된 분야이다. 이 글은 20세기 후반 미국 민속학에서 물질문화가 과연 어떻게 인식되었고 어떻게 연구되었는지를 살핀 것이다. 다만 설화를 연구하여 공식적으로 미국 최초의 민속학박사가 되었지만, 물질문화 연구로 주전공을 재설정한 워렌 E.로버츠(Warren E. Roberts, 1924~1999)의 연구에 한정하여 그 경향성과 의의에 대해 검토하고자 하였다. 로버츠는 설화연구자로 유명한 스티스 탐슨(Stith Thompson)의 제자였으나 고국 노르웨이에서 민속학을 연구한 경험을 계기로 물질문화 연구자로 전향하였다. 그 후 인디애나대학 민속학과 교수로 물질문화 분야를 담당하였다. 그의 물질문화 연구는 민중생활(folklife)이라는 테두리 속에서 혹은 민중생활과 관련하여 예술품(art), 공예품(craft), 건축물, 그리고 제작 도구를 대상으로 하여 이루어졌다. 로버츠가 말하는 물질문화는 이와 같이 사물(물건, 물질문화자료)로 구체화된 것이었다. 그의 이러한 물질문화에 대한 인식은 물질문화 연구를 지속적으로 활성화시키는 데 걸림돌이 된다. 그럼에도 전통적 공예품을 만드는 장인들을 주목한 것은 소비자보다 생산자를 훨씬 중시했기 때문이며, 사람 본위로 물질문화를 연구하는 길을 연 것이다. 또한 농민들의 생존활동 가운데 상당 부분을 수공기술의 관점에서 이해하려 한 점, 농부들의 삶과 활동을 생계형 수공기술(subsistence crafts)의 개념으로 연구한 점이 주목된다. 그의 물질문화에 대한 기본적인 시선은 산업화와 더불어 사라지는 민중들의 전통적 물질문화를 조사·연구·보전하는 것이었다. 물질문화에 대한 접근방법은 물질문화라는 대상을 중심에 놓고 관련되는 문화요소를 최대한 풍부하게 조사하여 연구하는 것이었다. 로버츠는 역사지리학적 방법, 연대기적 방법, 기능주의적 방법, 맥락주의적 방법으로 물질문화를 연구하였다. 그의 물질문화 연구는 미국 민속학 발전 초기에 수행되었으며, 야외박물관 설립 노력과 병행되었고, 민중생활의 맥락 속에서 풍부한 현지조사를 통하여 물질문화의 변천을 설명하고 분포지도를 작성하고, 기능적 고려와 적합성을 조사하여 서술하는 형태였다. 그는 장인들의 활동에 주목하였지만, 물질문화를 ‘행위의 체계’ 속에서 연구하는 학문적 전통을 분명하게 확립하지 못한 아쉬움이 있다. Material culture in the folkloristics of many countries is a field that began to be studied relatively late. This paper has examined how material culture was perceived and studied for American folkloristics in the late 20th century. It focused on studies by Warren E. Roberts (1924~1999) and investigated their tendency and meaning. Warren E. Roberts committed himself to studying folktales and became the first titlist of Ph.D. in folklore in USA. Later he changed his major field to the study of material culture. Roberts was taught by Stith Thompson, the famous researcher of folktales. However, he changed his research field to material culture after he studied folklore in Norway, his native country. Afterwards he became a professor in charge of material culture in department of folklore at Indiana University. He studied material culture within the frame of folklife, focusing on art, craft, architecture and manufacturing tools which were related to folklife. What he referred to as material culture was what was concrete in objects (things and physical matters). His perception of material culture is an obstacle to that continuously activates the material culture studies. Nevertheless, he paid attention to artisans/craftsmen who made traditional craftworks because he valued producers much more than consumers. Such an attitude led to the research of material culture which valued human beings. It is notable that he examined farmers’ subsistence activities in terms of crafts and that he studied farmers’ lives and activities from the viewpoint of subsistence crafts. His basic job for material culture was to survey, research and preserve traditional material culture of folk which was disappearing on account of industralization. His approach was to investigate and research as many cultural elements as possible related, placing the objects of material culture at the center. Roberts used a historical-geographical method, a chronological method, functionalism and a contextual approach to study material culture. His study of material culture was characterized by the following facts: his material culture study is made early in the American folkloristics; it was made along with efforts to establish an outdoor museum; and his study investigated and narrated changes of times, distribution-map drawing, and functional consideration and propriety through a lot of field studies in the context of folklife. Regrettably, though it paid attention to artisans’ activities, this study has not firmly established an academic tradition whereby material culture can be studied in behavioral systems.

자궁경부 상피종양에서 human papillomavirus 감염과 survivin 발현

윤재호,정동준,이정은,박동명,배동한,선우재근,백무준,김창진 순천향의학연구소 2004 Journal of Soonchunhyang Medical Science Vol.10 No.1

Human papillomavirus (HPV) has been considered a causative agent of uterine cervical carcinoma. HPV is a DNA oncogenic virus, which is well known as a causative virus in uterine cervical carcinoma. The virus is classified into two groups genotypically, low risk and high risk, according to the carcinogenic potentiality, and the determination of the viral genotype is important in clinical practice. Recently, numerous genotypes can be determined by high throughput method using DNA chip. Survivin is a recently characterized inhibitor of anti-apoptosis (IAP) protein, which is abundantly expressed in most solid and hematological malignancies, but undetectable in normal adult tissues. In this study, HPV genotypes are determined by DNA chip and the expression of survivin was examined by immunohistochemistry in 80 cases of uterine cervical intraepithelial neoplasia (CIN) and invasive carcinoma to see the roles of HPV and survivin in the carciogenesis of uterine cervical epithelial neoplasia. The results were as follows: 1. HPV positive rate was 72.5%, while negative rate was 27.5% in 80 cases of CIN and invasive carcinoma. The CIN and invasive carcinoma showed higher HPV positive rate (p <0.05). 2. HPV positive rate according to the histologic grade were 60%, 65%, 77% and 90% in CINI, CINII, CINII and invasive carcinoma, respectively. HPV positive rate showed increasing tendency according to the histologic grade, though there was no statistical significance. 3. The most frequent genotype was type 16 and the next were 58, 52, 18 and 33 in order of frequency. 4. Survivin was expressed in 96.3% of CIN and invasive carcinoma. The expression rate of survivin showed no significant difference between the histologic grade of CIN and invasive carcinoma, but showed tendency of increased expression rate in invasive carcinoma. 5. Survivin was expressed in HPV positive and in HPV negative each as in 95.5% and 96.6% respectively. There was no significant difference of survivin expression between HPV positive and negative cases. The above results suggest that HPV has no effect on the regulation of survivin expresson level in the uterine cervical intraepithelial neoplasia and invasive carcinomas.

관동맥질환에서 저밀도 지단백 입자 크기의 분포

임효영,김인숙,승기배,강동헌,전두수,장기육,박준철,이수영,홍순조,최규보 대한순환기학회 1998 Korean Circulation Journal Vol.28 No.8

플라즈마 표지소자의 제작

이상윤,라병욱,박동수,황인헌,이덕동,신영남,박성배,이동욱,박용석,박형근,손상호,권태근,채경락,정경득 慶北大學校 自然科學大學 1986 自然科學論文集 Vol.4 No.-

An Ac-type Plasma Display Panel (PDP) operating with Ne-Ar(0.1%) Penning mixture gas is fabicated. The characterics of the panel with electrodes covered with thin and thick dielectric layers are studied. The brightness of the Neon-orange light emitted by the panel measured as function of applied voltage and frequency. As an application, a graphic display system equipped with PDP showing still and moving pictures is made.

도시 불량주거지의 건축물 재료특성에 관한 연구 : 인천광역시 동구 「송현지구」 주거환경개선사업지구를 중심으로 Focus on the Housing Environment Amelioration Zone of Songhyun-Dong, Dong-gu, City of Incheon

이관구,박철만,이동배 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1

The purpose of this study is to investigate the characteristics of the building materials used for the housing in the urban squatter settlement. We chose Songhyun-Dong rehabilitation project started in the city of Incheon in 2000 according to the government program of housing amelioration scheme for the deteriorated low-income settlement area Detailed survey data of the physical situation of the area made for the project were examined and processed to scrutinize the traits of materials employed for the original houses. The result is given according to the location of the housing and type of plan, elevation, structure, and roof shape of the houses.

응급센터에 내원한 소아 사망 환자에 대한 임상적 고찰

김도연,이성훈,이상배,류민혁,이동진 대한소아과학회 2004 小兒科 Vol.47 No.1

플라즈마 EGR 조합시스템 전자제어 컴먼레일 디젤기관의 성능 및 NO_(x)ㆍTHC 배출물 특성

배명환,구영진,이동윤 慶尙大學校 經營行政大學院 2004 工學硏究院論文集 Vol.20 No.-

The aim in this study is to develop the combined turbo intercooler EGR system with a non-thermal plasma reactor for reducing exhaust emissions and improving fuel economy in ECU common-rail diesel engines. At the first step, the characteristics of performance and NO_(x) · THC emissions under four kinds of engine loads are experimentally investigated by using a four-cycle, four-cylinder, direct injection type, water-cooled ECU common-rail diesel engine with a combined turbo intercooler plasma exhaust gas recirculation(EGR) system operating at three kinds of engine speeds. The EGR and turbo intercooler system are used to reduce NO_(x) emissions, and the non-thermal plasma reactor and turbo intercooler system are used to reduce THC emissions. In this study, the plasma system is a flat-to-flat type reactor operated by a plasma power supply. The fuel is sprayed by pilot and main injections at the variable injection timing between BTDC 15˚ and ATDC 1˚ according to experimental conditions. It is found that the specific fuel consumption rate with increasing EGR rate is increased, but the fuel economy is better than that of mechanical injection type diesel engine as compared with the same output. Results show that NO_(x) emissions are decreased, but THC emissions are increased, as the EGR rate is elevated. NO_(x) and THC emissions are also slightly decreased as the applied electrical voltage of the non-thermal plasma reactor is elevated.

자동차 수동 트랜스미션 기어의 손상과정 예측

베효준,조연상,김동호,서영백,박흥식 동아대학교 생산기술연구소 2000 生産技術硏究所硏究論文集 Vol.5 No.2

The wear particles is released from the moving surfaces in gear systems of transmission and its morphology is directly related to the damage and failure to gear systems from which the particles originated. It is the effective method to diagnosis damage process of gear systems of automobile transmission to observe wear particle in gear oil. We tested with new transmission and took out gear oil according to drive distance. To be applied to damage diagnosis of gear system in transmission of automobile, 4 shape parameters of wear particles in gear oil were calculated and wear volume were presumed with the image processing system.

한국 상장기업의 IT자본과 노동 및 비IT자본의 대체성에 관한 연구

문성배,홍동표 한국은행 2004 經濟分析 Vol.10 No.2

본 연구는 2000-2002년까지의 한국 164개 상장기업에 대한 자료를 이용하여 IT자본과 노동 및 비IT자본간의 대체탄력성(elasticity of substitution)을 측정하였다. 특히 생산요소간 대체성의 척도로서 널리 쓰이고 있는 Allen 대체탄력성(Allen elasticity of substitution)의 문제점을 지적하고 Allen 대체탄력성 뿐만 아니라, 가격탄력성, Morishima 대체탄력성(Morishima elasticity of substitution), 그리고 shadow 대체탄력성(shadow elasticity of substitution)을 측정하였다. 본 연구의 추정결과에 따르면, 첫째, IT자본은 노동과 비IT자본에 대한 대체재(substitute)인 것으로 나타났으며, 우리나라 기업들의 경우 IT자본이 노동을 대체하는 정도보다 IT자본이 비IT자본을 대체하는 정도가 큰 것으로 나타났다. 또한 비제조업보다는 제조업에서, 정보화가 덜 된 기업들보다는 정보화가 많이 된 기업들에서 IT자본의 노동과 비IT자본에 대한 대체성이 강한 것으로 나타났다. This paper examines the substitutability of IT capital for other inputs, such as labor and non-IT capital, using the data on 164 Korean firms from the period of 2000-2002. Estimating various elasticities of substitution between IT capital and other inputs, we find that IT capital is a substitute for labor and non-IT capital. In particular, we find that IT capital is more substitutable for non-IT capital than for labor. We also find that the estimated elasticities of substitution between IT capital and other inputs are higher for manufacturing firms than for non-manufacturing firms, and higher for IT-intensive firms than for less-IT-intensive firms.