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.

고 Mn-Cr 강의 조사손상에 미치는 전자선 조사 온도의 영향

배동수,정호신,강창용,남승훈,이해무 대한금속재료학회 2004 대한금속·재료학회지 Vol.42 No.3

The effect of electron-beam irradiation temperature on irradiation damage of 12%Cr-15%Mn austenitic steel for structural material of nuclear and/or fusion reactors from the point of view of the reduced activation was investigated by using the 1,250 keV HVEM and an energy dispersed X-ray analyzer(EDX) in a 200 keV FE-TEM with beam diameter of about 0.5 nm. Void formation was not observed in irradiated specimen. The dislocation loop growth was observed and the density and size of dislocation loop were increased with irradiation dose. Irradiation-induced segregations of Cr and Mn at grain boundary were also observed by electron-beam irradiation condition. The amount of Mn segregation was increased with irradiation temperature, however, segregation phenomenon was disappeared in the case of Cr.

약물 유해반응 보고지침 -임상시험의 안전성에 관한 정보 관리지침 -

지동현,김훈교,배진우,손동렬,김인범,전용관,박혜연 大韓臨床藥理學會 1998 臨床藥理學會誌 Vol.6 No.2

족관절 삼과골절에서 후과골절편이 외상후 관절통증에 미치는 영향

배서영,신동훈 대한골절학회 2003 대한골절학회지 Vol.16 No.1

목 적 : 족관절 삼과골절에서 후과 골절편의 정복과 고정 여부에 관하여는 논란이 있으나 골절편의 크기가 관절면의 25~30% 이상을 차지하는 경우 고정이 필요하다는 주장이 일반적으로 받아들여지고 있다. 저자들은 후과 골절편의 크기 및 고정 여부가 실제로 임상결과에 영향을 주는 가장 중요한 인자인지 알아보고자 하였다. 대상 및 방법 : 본원에서 동반손상이 없는 족근관절 삼과골절로 치료받았으면서 내과 및 외과의 해부학적 정복이 이루어진 73명중 2년 이상 추시 가능하였던 30명을 대상으로 하였다. 수상 직후와 정복 직후의 측면사진에서 후과 골절편의 크기를 관절면을 차지하는 정도(%)로 측정하고 정복 직후 사진에서 잔존하는 전위 정도를 골편 간극과 관절면의 층짐으로 나누어 측정하였다. 또한 의무기록의 조사를 통해 후과의 고정 여부, 관절운동의 시작시기, 체중부하 시작시기를 조사하였다. 임상 결과는 AOFAS(American Orthopaedic Foot and Ankle Society)의 기준에 따라 통증, 기능, 정렬에 대해 점수를 매기고 추시상 관절의 통증이 남은 군과 통증이 없는 군으로 나누어 각 인자들 중 어떤 인자에 의해 좌우되는지 로지스틱 회귀분석과 Chi-square교차분석을 통해 유의수준 5%로 알아보았다. AOFAS 점수 중 기능이나 정렬 면에서는 차이가 없었으며 관절 불안정을 보이는 경우도 없었으며 운동범위의 제한을 보이는 경우가 1예 있었다. 관절통을 호소하는 군은 7명, 통증이 없는 군은 23명이었고 두 군간에 잔존하는 골절편의 간극과 관절면의 층짐 정도는 유의한 인자였으나 골편의 크기나 고정여부, 관절운동 시작시기, 체중부하 시작시기 등에서는 유의성을 검증할 수 없었다. 결 론 : 삼과골절에서 후과 골절편은 크기나 고정 여부보다도 정복 후 골절편의 간극이나 층짐이 임상결과, 특히 관절통증에 더 영향을 미치므로 고정 여부에 상관없이 정복후 정복 상태에 대한 정확한 평가가 필요하고 골편의 크기에 상관없이 해부학적 정복이 필요할 것으로 사료된다. 또한 후과의 부정위는 내외 양과의 골절이 해부학적으로 정복된다면 족관절 기능이나 불안정보다는 통증을 유발하는 것으로 사료된다. Purpose : There are some criticisms of indication for internal fixation of the posterior malleolar fragments in trimalleolar fractures. We tried to find out clinical and radiologic factors which affect on a clinical outcome of triballerolar fractures. Materials and Methods : Thirty three patients who were treated for trimalleolar fractures and given anatomical reduction of lateral and medial malleolus were included. We divided patients into two groups, a group without the pain and the other group with the pain. Preoperative and postoperative lateral plain radiographic films were used to estimate fragment size, post-reduction gap and step off. By reviewing the medical records, other factors such as the time of ankle motion, weight loading and whether posterior malleolus was fixed. Or not were studied. A clinical outcome was evaluated by ASFAS(American Orthopaedic Foot and Ankle Society) scaling system. We performed statistical analysis using Logistic regression analysis and Chi-square test on each factors. Results : There was no definite difference between two groups on the functional outcome. There was one case showing limited ankle motion. Seven patients were involved in the group with the pain and 23 in the group without the pain. The remnant fracture gap and step off of joint surface statistically showed the meaningful corellation with the pain but a fragment size and a surgical fixation, time of motion and weight loading did not show any significances. Conclusion : We doubt the significance of the size of posterior malleolar fragment. We concluded that anatomical reduction of posterior malleolus is the most significant factor of a clinical outcome regardless of the size or internal fixation, especially the pain after trimalleolar injuries.

패류를 이용한 분말조미료의 저장안정성

배태진,강훈이,강동수 여수대학교 1998 論文集 Vol.12 No.2

Dried shellfish condiments were manufactured using low-usefulness marine shellfishes, and their stability during storage at 24±4℃ for 90 days were investigated. Moisture contents of dried shellfish condiments using pen shell and cockle shell were 3.8% and 3.7%. Total nitrogen and amino nitrogen were 78.8%, 48.9% and 74.2%, 45.4%, the ratio of amino nitrogen in total nitrogen were 61.2% and 62.1%, respectively. And drying yield, solubility and hygroscopity at Aw 0.88 were 8.2%, 73.6%, 6.1% in pen shell, 9.8%, 76.9%, 6.6% in cockle shell, respectively. When storage at 24±4℃ for 90 days, the contents of chemical composition were little changed. Dried shellfish condiments using pen shell, the contents of moisture, total nitrogen and amino nitrogen were little increased, and carbohydrate, ash, adsorption rate and solubility were littel decreased. And bacterial growth before storage and 90 days storage were 2.3ㆍ20²cfu/ml and 6.8ㆍ20²cfu/ml, respectively. And using cockle shell was similar at pen shell. Free amino acid contents in dried shellfish condiments using pen shell and cockle shell were 3,156.21mg% and 4,175.0mg%, respectively. The major free amino acids in dried shellfish condiments were glutamic acid, arginine, leucine, glycine and aspartic acid in pen shell, glutamic acid, proline, arginine, glycine and lysine in cockle shell. And their ratios in total free amino acid were above 49% and 70%, respectively. And during storage period, orders and contents of amino acid composition were not changed.

TSC합성구조 바닥판의 진동에 대한 사용성 평가

김도훈,서동기,김성배,김상모,이창남 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2(구조계)

Recently, Building floors are being larger and longer. This is contributed from the development of new design methods and high strength and light weight materials. However, as such longer span floor systems may provide less damping, and have longer period. Therefore, the vibration problem of buildings has become more important. In this research, floor vibration, natural frequency and damping ratio using TSC(T-type Steel Composite beam) composite system were measured by experiments and foreign criteria for serviceability evaluations were applied with responses obtained by walking and heel drop loads. The purpose of this study is to evaluate the serviceability for floor vibration according to the peak acceleration and natural frequency in TSC composite slabs.

대뇌 기저핵 신경세포 일차배양에서 망간에 의해 유도된 Appoptosis : 형태학적인 소견

신동훈,김상표,정용욱,배재훈,송대규,백원기 大韓産業醫學會 2000 대한직업환경의학회지 Vol.12 No.1

목적 : 본 실험은 대뇌기저핵의 신경세포를 배양하여 망간(MnCl₂)을 투여한 후 망간독성에 의한 신경세포의 apoptosis를 형태학적인 소견으로 관찰하였다. 방법 : 배양된 신경세포에 0.01에서 10μM Mnc12를 48시간동안 처리한 후 TUNEL (TdT-mediated dUTP Nick End Labelling)법 및 투과전자현미경학적으로 관찰하였다. 결과 : TUNEL방법을 이용하여 관찰한 결과 TUNEL반응에 갈색으로 양성반응을 나타내는apoptotic 세포의 수가 대조군에 비해 MnCl₂를 투여한 군에서 유의하게 높게 나타났으며(P〈0.05), 투과전자현미경학적 소견상 대조군의 신경세포들은 핵인(nucleolus)이 두드러지게 특징적으로 보이면서 핵막과 세포질내 소기관들이 잘 보존되어 있으며, 세포질내망(ER)과 사립체(mitochondria)를 특히 많이 가지고 있었다. Mnc12를 48시간 동안 처리한 군에서 이질염색질(heterochromatin)이 핵막으로 이동하면서 응집되어 있었으며, 핵내 불규칙한 형태의 염색질이 나타나 분절이 진행되는 소견을 보였고, Apoptosis의 가장 특징적인 초기 소견인 막으로 둘러싸인 반달모양의 핵내염색질의 분절편(fragment-ed chromatin)과 주위의 상대적으로 정상적인 소기관으로 구성된 apoptotic body를 관찰할 수 있었다. 결론 : 신경세포에서 망간에 의해 apoptosis가 유도됨을 형태학적인 방법으로 확인할 수 있었으며 망간에 의한 세포사망양상에 apoptosis가 하나의 기전이 될 수 있을 것이다. Objectives : Manganese is cytotoxic to the central nervous system including basal gan-glia. Its toxic mechanism is related to oxidative stress, mediated by toxic free radicals but is specultives. In the present study , we have investigated to manifest apoptosis in man-ganese-induced cytotoxicity in primary neuronal cell culture of rat basal ganglia. Methods : To detect apoptotic neuronal cells were stained by the terminal deoxynu-cleotide (TdT) -mediated dUTP nick end-labelling (TUNEL) method and apoptotic changesin nuclei of neurons were observed by electron microscopy. Results : We showed that TUNEL immunostain showed brownish signal in the nuclei of apoptotic cells and the proportions of apoptotic cells in Manganese treatment groups were more higher than controls. On transmission electron microscopy, there were chromatine condensation with margination toward nuclear membrane and condensation of cyto-plasm in the treated with luM MnCl²for 48 hours in a basal ganglia neurons. Apoptotic bodies were found and consisted of semilunar-like condensed nuclei with relatively intact cytoplasmic organelles. Conclusions : Apoptosis appears to be one mechanism in the manganese-induced net-ronal cell death. Manganese intoxication is a convenient model for apoptosis study.

당뇨병성 합병증을 가진 환자에서 혈증 Erythropoietin 농도

김동규,유기동,허광식,김상용,윤성호,조영신,권용은,김태원,김건영,정종훈,배학연 조선의대 1998 The Medical Journal of Chosun University Vol.23 No.1

紡絲工程에서의 Emulsion Fume 處理를 위한 充塡塔 適用에 관한 硏究

최동훈,박진식,장성호,김일배,서정민,김장호 동아대학교 환경문제연구소 1996 硏究報告 Vol.19 No.2

This study was carried out to interpret hydraulic behavior and component analysis of the emulsion fume, laboratory work of mass transfer in the packing tower which packed 50mm plastic Hiflow-ring. The results from experiment are as follows : 1. The component of emulsion fume is Cyclododecane, 1-Tridecene, 4-Nonene 5-butyl. The kinds of Alkene contained approxymately 76.23 percent. 2. To compare with conventional packing, 50mm Hiflow-ring could save energy because of low pressure drop under high load. 3. The unique magnituteds of packing witch was used are as follows. Cv = 5.18 × 10^(-4) , m = 0.683, n=0.462 so we can predict efficiency which occurres. 4. To require plant of the packing tower in the gas capacity factor 2.7 (Kg^(1/2) m^(-1/2) s^(1))

Capsicum chinense, 재래종 및 저항성 고추 유전자원에서 역병 저항성 계통 선발

김정훈,여승호,김동우,배수연,한정혜,황희숙,김병수 慶北大學校農業科學技術硏究所 2002 慶北大農學誌 Vol.20 No.-

2000년도에 검정에서 역병에 살아남은 개체들로부터 채종하여 육성한 Capsicum chinense 31계통에 대하여 역병 저항성을 검정한 결과 고도의 저항성을 나타내는 것은 발견되지 않았다. 2001년도의 검정에서 역병에 살아남은 개체로부터 채종한 재래종 26계통에 대하여 다시 역병 저항성 검정을 실시한 결과 KC180, KC230, KC195, KC194에서 다수의 개체가 살아남아 저항성을 나타내었다. 그러나 KC180과 KC230은 각각 AC2258과 CM334와 혼종된 것으로 관찰되었다. KC195와 KC194는 재래종의 형질을 유지하고 있는 것으로 관찰되었다. CM334의 보존 증식과정에 자연교잡이 일어난 것으로 보여 이의 순도향상을 위하여 채종년도별로 시료를 꺼내어 역병저항성 검정을 실시한 결과 가장 오래된 1992년도 채종종자에서부터 약간의 이형주가 관찰도기 시작하여 1995년부터 2001년도까지 시간이 경과함에 따라 많이 변형되어 있는 것을 알 수 있었다. 1992년도 종자에서 이형주를 제거하고 원형의 개체로부터 자식종자를 대량으로 채종하였다. 함께 공시한 AC2258은 순수한 것으로 확인되었다. 1995년도 채종 CM334 종자에서는 비록 혼종은 되었으나 측지발생이 적은 개체들이 발견되어 이들을 개체 선발하여 역병에 저항성이며 측지발생이 적은 계통으로 육성하고 있다. A total of 31 c. chinense lines selected from 2000 screening were tested again for resistance to P. capsici but resistance was not found in the lines. A total of 26 selections from Korean land races tested 2001 spring were tested again for resistance to P. capsici. KC180, KC230, KC195 and KC194 showed moderate resistance to P. capsici. However, it was apparent on the basis of hortivultural characteristics that KC180 and KC230 had been naturally crossed with AC2258 and CM334, respectively. CM334 and AC2248 seed lots that were increased in different years were taken out and tested for resistance to improve their genetic purity because the resistant genetic resources have been showing some off-types in the population. Off-types began to be found in 1992 seed lots and the proportion and degree of the offs was increasing with time up to 2001. Plants true to the type in 1992 seed lots were selected and their inbred seeds were mass produced in a net cage in the greenhouse. AC2258 included in the experiment number of lateral branching at cotyledonary axil, although they were off from the original in the experiment together was uniform. In 1995 seed lost of CM334, plants with resistance to P. capsici and low or no number of lateral branching at cotyledonary axil, although they were off from the original CM334, were found and selection was applied to breed lines fixed in the characters.