Effects of Test Temperature on Low Cycle Fatigue Behaviors in Large Mold Steel

Jong‑Ho Shin,Jehyun Lee 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.7

A mold steel for plastic injection was subjected to low cycle fatigue (LCF) tests at temperatures of 25, 200, and 250 °C. LCFtests were carried out at a total strain amplitude (Δεt/2) from 0.004 to 0.012 under a constant strain rate of 0.01 s–1. Transmissionelectron microscope images showed that cyclic loading accelerated dislocation recovery as the LCF test temperatureincreased. The LCF life increased as a result of improvement in the ductility associated with dislocation recovery as the testtemperature increased. The LCF behavior at the test temperature range followed the Coffin–Manson equation. Empiricalequation was proposed to predict the LCF life of the mold steel within the test temperature range.

Modified Microstructure Selection Map and Growth Conditions of the Band Structure in Directionally Solidified Hypo-Peritectic Alloys

Jong‑Ho Shin,Jehyun Lee 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.5

Considering the variation of the solid/liquid interface morphology with a growth condition, microstructure selection map inperitectic system was modified by comparing growing α (primary phase) interface tip temperature and β (peritectic phase)nucleation temperature. The results were proved experimentally in hypo-peritectic Sn–Cd alloys by delicate directionalsolidification experiment under the diffusive growth condition using capillary thin tube. When β-phase took over α-phaseand grew a short distance as the leading phase, the instability of β-phase was first observed experimentally. This phenomenawas explained by constitutional undercooling, which was present temporarily in liquid ahead of the β/l interface.

Nrf2-Heme oxygenase-1 modulates autophagy and inhibits apoptosis triggered by elevated glucose levels in renal tubule cells

Joo Heon Kim,김경민,Jin Uk Jeong,Jong-Ho Shin,신재민,방기태 대한신장학회 2019 Kidney Research and Clinical Practice Vol.38 No.3

Background: Autophagy is a highly balanced process in which lysosomes remove aged and damaged organelles and cellular proteins. Autophagy is essential to maintain homeostasis in the kidneys. Methods: Using human renal tubule cells HK-2, we assessed the impact of high glucose (HG) on autophagy. We also evaluated the capability of sulforaphane (SFN) to protect the HK-2 cells from HG-induced apoptosis by modulating autophagy. Results: SFN modulated autophagy and decreased apoptosis in the HK-2 cells that were cultured in 250 mM glucose medium for two days. The reactive oxygen species (ROS) levels increased, as expected, in the cells cultured in the 250 mM glucose medium. However, the SFN decreased the ROS levels in the HK-2 cells. The overexpression of heme oxygenase-1 (HO-1) by SFN decreased the expression of LC3 and beclin-1. LC3 and beclin-1 were involved in the downregulation of caspase-3 that was observed in the HG-induced cells. Conclusion: The activation of nuclear factor E2-related factor 2 (Nrf2)-HO-1 inhibited ROS expression and subsequently attenuated autophagy and cell apoptosis after HG injury was decreased. HG injury led to the activation of autophagy and HO-1 in order to combat oxidative stress and protect against cell apoptosis. Therefore, HO-1 activation can prevent ROS development and oxidative stress during HG injury, which considerably decreases autophagy and apoptosis.

척수신경세포에서의 아포프토시스 관련인자에 관한 면역조직화학 연구

김종민,정윤희,신정민,박경한,조사선,백상호,차중익 대한해부학회 1999 Anatomy & Cell Biology Vol.32 No.4

말 기생충성 동맥염 2예

신태균,김승호,배종희,이두식,임윤규,이수길 濟州大學校 農科大學 動物科學硏究所 1992 動物科學論叢 Vol.7 No.1

Two cases of verminous arteritis were chosen for this case. These horses were originally submitted for necropsy in the Cheju horse race. Case 1 : At necropy, there was increased ascite, thickened ab-dominal aorta at junction of cranial mesenteric artery. In the aorta, there was a long thrombus embed-ded with strongylus vulgaris larvae. Some larvae were also firmly attached in the aortic intima Histologically, there was infiltration of neutropliils, eosinophils, and macrophages in the tunica media. At the junction of thrombus and arterial intima, there was proliferation of vessels. Case 2 : At necropsy, there was thickened abdominal aorta, which showed typical verminous arteritis with thrombus. Histologically, ceseous tissues with haematopoietic tissue was recognized in the aortic wall.

鷄龍山 森林土壤의 特性에 關하여

辛昌男,宋鎬京,朴鍾聲 忠南大學校 環境問題硏究所 1983 環境硏究 Vol.1 No.2

In order to determine the characteristics of soil in Mt. Gyeryong, the content of primary minerals and chemical and physical properties of forest soil were analyzed. The parent rock of forest soil were consisted of pink feldspar granite and gneissose granite. The weathered parent rock contained about 64% of plagioclase and quartz. The content of available phosphorus of soil resulted from weathering process of pink feldspar granite was higher than that of the gneissose granite soil. But the contents of K and of the latter were higher than those of the former. Both types of soil texture were mainly loam and clay loam The differences of chemical soil properties between Pinetum consociation and Quercetum consociation were as follows:the contents of the organic matter, total exchangeable bases, NO^-_3-N and NH^+_4-N of Quercetum consociation were higher than as compared to those Pinetum consociation in the pink feldspar granite region, the contents of total nitrogen, available phosphorus, total exchangeable bases, Mg^++ and NO^-_3-N of Quercetum consociation were higher than as compared to those of Pinetum consociation in the gneissose granite region.

웨이브렛 계수 Zero Crossings를 이용한 영상의 잡음제거 및 압축

신재호,이용준,은종숙,이성우 동국대학교 산업기술연구원 1997 산업기술논문집 Vol.10 No.-

윤곽선이나 에지같은 영상 데이터의 중요한 성분들은 웨이브렛 계수의 zero crossings를 통해 검출할 수 있다. 이런 방법은 영상의 패턴 인식에 관한 연구에서 sharp variation points를 검출하는데 사용되었다. 웨이브렛 변환과 zero-crossings를 거쳐 국부 극치의 위치를 검출하는데 이 방법을 적용하여서 영상의 잡음제거에 사용하도록 개선하였다. 더욱이 영상 데이터에서 전체 영상의 픽셀과 정보를 저장하는 대신, 대부분의 중요한 성분을 효과적으로 몇몇 국부 극치값으로 압축하였다. 그 결과 새로 개선된 기법은 패턴 인식 분야에서만 아니라 높은 압축률의 잡음 제거에도 사용될 수 있다. The important image data components such as contours and edges could be detected by zero crossings of wavelet coefficient. This method has been used for the studies on pattern recognition of images to detect sharp variation points. We have applied it to detection of the position of local maxima through zero-crossings and wavelet transform, so that it is improved to be used for noise-eliminating of image. In addition it could compress the image data into a few of local maxima which held the most of important component efficiently without saving All image pixels and information. As the result, the newly improved method could be implemented not merely for the field of pattern recognition but for that of noise removal at the higher compression ratio.

지역복지 정보네트워크의 구축에 관한 연구

신동면,한상연,김종호,이호창,김민용 한국정책학회 2004 韓國政策學會報 Vol.13 No.1

이 논문에서는 정보기술이 지역복지 전달체계의 개편에 기여할 수 있다는 인식을 바탕으로 지역복지 정보네트워크를 구축하기 위한 모델과 지역복지 정보네트워크를 위한 컨텐츠 구성 방안 등에 대하여 논의하고 있다. 정보의 공유와 상호협력 관계를 충실하게 구혈할 수 있는 정보네트워크 구축방식은 지역복지 전달과정에 관련된 공급자, 수혜자, 후원자, 그리고 정부를 포함한 모든 당사자들을 상호 연결하는 e-허브 모델이 바람직하다. 지역복지 네트워크 허브는 지역복지 전달과정에서 각 주체들이 정보네트워크에 올린 원시정보를 분류?축적?갱신함으로써 사회복지서비스의 수급을 연결시키는 역할을 담당하기 때문에 지방자치단체가 운영의 책임을 져야 한다. 지역복지 정보네트워크는 지역복지 전달과정에서 5C 활동-컨텐츠(Contents), 의사소통(Communication), 커뮤너티(Community), 협업(Collaboration), 기여(Contribution) -을 촉진할 것이다. 이중에서 특히 컨텐츠의 수준은 지역복지 정보네트워크가 효과적으로 운영되기 위한 관건이 된다. 이에 본 논문에서는 공급자, 수혜자, 후원자, 그리고 정부가 지역복지 정보네트워크의 운영을 위하여 제공해야 할 컨텐츠를 구체적으로 예시하고 있다. 지역복지 정보네트워크는 5C 활동을 통하여 지역복지 전달과정에서 관련 당사자들 간의 상호, 협력적 관계를 지속시킴으로써 지역복지 전달체계의 효율성, 적절성, 통합성, 전문성, 접근성을 제고하는 데 기여할 것이다.

몰리브덴이 첨가된 Stellite 6 합금의 마모와 부식특성

申種喆,金在洙,李德悅,梁在雄,尹珍國,盧大虎,李種權 대한금속재료학회 2002 대한금속·재료학회지 Vol.40 No.10

Hardfacing layers of Stellite 6 with different molybdenum content are deposited on AISI 1045-carbon steel using Plasma Transferred Arc welding(PTA) machine. The microstructures, wear and corrosion resistances of the hardfacing layer are investigated in order to clarify the effect of molybdenum in Stellite 6 alloys. The microstructural characterizations of the hardfacing layers are performed using X-ray diffraction, back scattered electron images, and scanning electron microscopy. With an increase of Mo contents, M_6C type carbide are formed instead of Cr-rich type carbides, and so this microstructural change enhanced the mechanical properties such as wear and corrosion resistance of a Mo-modified Stellite 6 alloy.

구미지역 상설시장의 유통업 현황분석 및 활성화 방안

신호균,김정태,송종호 한국의사결정학회 2002 경영과학연구 Vol.11 No.-

Due to a great difficulty of permanent market with the advent of great discount stores and foreign distributors, this paper is to analyze the current situation and to present suggestions for the development of the permanent market Gumi. To achieve the objective, a field study has been conducted using the questionaires for the consumers and the interviews with the merchants of the 5 major permanent markets in Gumi area. The study is based on the pilot study by civil servants and the representatives of the merchants. Considering the problems the permanent market in Gumi it is suggested that we approach not from the viewpoint of competitive relationship but from that of mutually cooperative relationship. Then, the distribution industry will be able to enhance the life quality of citizen and develop regional community.