Effect of Mn and C on Age Hardening of Fe–Mn–Al–C Lightweight Steels

Sung‑Won Park,Jun Young Park,Kyong Mox Cho,Jae Hoon Jang,Seong‑Jun Park,Joonoh Moon,Tae‑Ho Lee,Jong‑Ho Shin 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.3

The effects of Mn and C content on the age hardening of Fe–Mn–Al–C lightweight steels, which have austenitic or duplex(austenite and ferrite) microstructures, were investigated. An increase in Mn content induced a delay of the age hardeningthat is caused by the formation of intra-granular κ-carbides. In order to interpret the effect of Mn content, first-principlescalculations were conducted using the supercells of Fe24Al8C8,Fe24Al8C7,Fe24(Al7Mn)C8, and Fe24(Al7Mn)C7. The calculationsshowed that an increase in Mn content could be the source of the delay of the intra-granular κ-carbide formation bysuppressing C atom’ occupation of the vacancy at the body-centered site of L12. An increase in C content accelerated theformation of intra-granular κ-carbides, which induced the intense age hardening, and coarse inter-granular κ-carbides, whichresulted in significant decrease in impact absorbed energy due to inter-granular fracture.

코아-셀 구조를 가지는 전도성 폴리피롤 나노섬유를 이용한 메탄올 센서 제작

전태선 ( Tae Sun Jun1 ),이성호 ( Sung Ho Lee ),김용신 ( Yong Shin Kim ) 한국센서학회 2014 센서학회지 Vol.23 No.6

Electrically conductive polypyrrole-polyvinylpyrrolidone (PPy-PVP) nanofiber mats with a core-shell structure have been successfully fabricated by a two-step process: the formation of FeCl3-containing PVP nanofiber mat by electrospinning, and the vapor-phase polymerization (VPP) of pyrrole monomer on the mat in a sealed chamber at room temperature. Surface morphology and chemical composition of the PPy-PVP mat were characterized by SEM, EDX and FTIR analyses. The as-prepared nonwoven mat was composed of PPy-PVP nanofibers with an average diameter of 300 nm. The sheet conductivity of the nanofiber mat was measured to be approximately 0.01 S/cm by a four-point probe. We have also investigated gas-sensing properties of PPy-PVP nanofiber mat upon exposure to methanol vapor. The PPy-PVP nanofiber sensors were observed to have excellent methanol-sensing performance. The nanofiberbased core-shell nanostructure could give an opportunity to fabricate a highly sensitive and fast response sensor due to its high surfaceto-volume ratio.

소아 심장 CT 검사시 Dual Source CT의 High pitch mode를 이용한 선량감소에 관한 연구

이예나(Ya Na Lee),강헌효(Heon Hyo Kang),손성실(Sung Sil Son),박찬혁(Chan Hyuk Park),현진경(Jin Kyung Hyun),신명호(Myung Ho Shin),김준혁(Jun Hyuk Kim),강동원(Dong Won Kang) 대한CT영상기술학회 2012 대한CT영상기술학회지 Vol.14 No.1

I. Purpose This study examines if accurate images can be realized with less dose than sequential mode, one of the existing methods applying DSCT’s high-pitch mode in pediatric cardiography. II. Materials and Methods For 20 patients who came to our hospital from Jan. 1 to Jun. 30, 2011, a test was carried out using MDCT 128 channel dual source; Somatom Definition Flash (Siemens Medical System: Germany). As the test method, the veins of the lower limbs of the patients were secured and contrast medium of 7ml was injected at 0.3ml/s anda CT scan was carried out about 36 s. later. Af first, sequential mode was used, and then high-pitch mode was followed as follow-up examination. The DLP (Dose Length Product) provided by the equipment and effective dose were compared for the assessment of the dose exposed to the patients, after the CT scan. The effective does was calculated by multiplying children’s chest index: 0.021 of the effective dose rate of EUR16262 (European Guide) to DLP value. The images scaned in high-pitch method were compared and assessed quantitatively by a heart decoding specialist and 2 radiologists if the typical diseases of pediatric cardiacs such as coarctation of aorta, atresia of the pulmonary artery and Tetralogy of Fallot can be assessed. III. Results When it was compared to sequential mode, one of the existing cardiography, the effective dose exposed to the patient had decrease by 32% in high-pitch mode. As a result of a comparison with imaging assessment, it was also evaluated as a better imaging than sequential mode IV. Conclusion Pediatric Cardiography using high pitch in Dual source MDCT showed superior effects on the reduction of exposed does than sequential mode, which is considered a useful testing method. 목적 본 연구에서는 소아 심장 검사 시 DSCT의 High-pitch mode를 적용하여 기존의 검사방법 중 하나인 Sequential mode보다 적은 선량으로도 정확한 영상을 구현할 수 있는지 알아본다. 대상 및 방법 2011년 1월 1일부터 6월 30일까지 본원에 내원한 20명의 환자를 대상으로 하여 MDCT 128 channel dual source; Somatom Definition Flash(Siemens medical system: Germany) 장비를 사용하여 검사를 시행하였다. 검사방법은 환자의 하지에 정맥을 확보하고 조영제를 0.3 ml/s로 7ml를 주입한 후 36초 후에 CT검사를 하였다. 처음에는 Sequential mode로 검사한 후 추적 검사할 땐 High-pitch mode로 검사한다. 환자가 받은 피폭선량의 평가는 선량평가는 CT검사 후 장비에서 제공하는 DLP(dose length product)와 유효선량(effective dose)를 비교하였다. 유효선량은 DLP 값에 EUR16262(European Guide) 유효선량비 중 소아 흉부 지수 0,021을 곱하여 계산하였다. 검사한 영상을 심장 판독 전문의 1명과 방사선사 2명이 high-pitch mode로 검사한 영상을 소와 심장의 대표적 질환인 대동맥협착증, 폐동맥 폐쇄증, 팔로씨 사증을 평가할 수 있는지 비교하여 정성적으로 평가하였다. 결과 기존의 심장 검사방법 중 하나인 Sequential mode와 비교했을 때 High pitch mode로 검사했을 때에 32%의 선량 감소 효과가 있었다. 또한 영상 평가 비교 결과 Sequential mode 보다 좋은 영상으로 평가되었다. 결론 Dual source MDCT로 소아심장 검사를 할 때 high pitch mode를 이용하면 sequential mode로 검사했을 때보다 환아가 받는 피폭선량은 낮고 더 우수한 영상을 획득하여 심장질환을 진단하는데 유용한 검사법으로 사료된다.

실용음악 전공 학생들의 발성치료 전후 성대 및 음성 특성 비교

황연신,심미란,김철준,최용석,김상연,최찬호,선동일,Hwang, Yeon Shin,Shim, Mi Ran,Kim, Chul Jun,Choi, Yong Suk,Kim, Sang Yeon,Choi, Chan Ho,Sun, Dong Il 대한후두음성언어의학회 2016 대한후두음성언어의학회지 Vol.27 No.2

Background and Objectives : Many students major in applied music singing have various difficulties in phonation when they sing or perform. But the studies about this cause are lack. The purpose of this study is whether singing voice therapy based on vocal music is effective or not to applied music singing students that have difficulties in phonation. Materials and Methods : Singing voice therapy program had been done to 8 students major in applied music singing during 7 weeks. We did laryngeal stroboscope, perceptual, acoustic and aerodynamic examination before and after singing voice therapy to this students. And we studied post examination results have differences or improvements compared to pre examination results. Results : Four male students don't have effective improvement after singing voice therapy but they shows slight improvement in aerodynamic examination values compared to pre examination values. Four female students shows improvement in aerodynamic examination values and pitch range increasing. Above all, one student's vocal nodules disappeared after singing voice therapy. Conclusion : Singing voice therapy based on music singing is very effective to the students major in applied music singing. Above all, their curriculum in applied music singing should include phonation training based on music singing before training perform and technic practices.

[PF-0011] Identification of freesia infecting viruses based on next-generation sequencing technique in Korea

Jun-Sung Shin(Jun-Sung Shin ),Jung-Heon Han(Jung-Heon Han ),Seong-Kyeong Lee(Seong-Kyeong Lee ),Yu-Ju Shin(Yu-Ju Shin ),Myunghoon Ko(Myunghoon Ko ),Hoseong Choi(Hoseong Choi ) 한국육종학회 2022 한국육종학회 공동학술발표집 Vol.2022 No.-

The Effects of Proprioceptor Training and Vestibular Organ Training on Balance Ability of Adults

Sang Bin Lee,Ok Kon Moon,Jung Hyun Choi,Ho Jung An,Hee Joon Shin,Nyeon Jun Kim,Si Eun Park,Young Hwa Song,Kyung Ok Min 국제물리치료학회 2014 Journal of International Academy of Physical Ther Vol.5 No.1

The purpose of this study was to analysis of the effect of proprioceptor training and vestibular organ training for balance ability. The subjects was consist of two different subjects group, proprioceptor training group and vestibular organ training group. Proprioceptor training group consisted of 10 subjects and vestibular organ training group consisted of 10 subjects. Training was performed 3 times per week, 30 minutes per day, for 3 weeks. Balance ability analysis was performed using Romberg's one leg standing test and BT4 when opened eyes and closed eyes. The analysis results were as follows. There was no significant differences in balance after the training in both groups when they opened their eyes(p<.05). But there was significant differences in balance after the training in both groups when they closed their eyes(p<.05). And there was no significant difference in balance after the training between the proprioceptor training group and the vestibular organ training group when they closed their eyes(p<.05). Given the above results, proprioceptor training and vestibular organ training enhanced balance but there was no significant difference between the two methods.

Transarterial chemoembolization versus resection for intermediate-stage (BCLC B) hepatocellular carcinoma

( Jun Young Kim ),( Dong Hyun Sinn ),( Geum Youn Gwak ),( Gyu Seong Choi ),( Aldosri Meshal Saleh ),( Jae Won Joh ),( Sung Ki Cho ),( Sung Wook Shin ),( Keumhee Chough Carriere ),( Joong Hyun Ahn ),( 대한간학회 2016 Clinical and Molecular Hepatology(대한간학회지) Vol.22 No.2

Background/Aims: Several studies have suggested that surgical resection (SR) can provide a survival benefit over transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) at the intermediate stage according to the Barcelona Clinic Liver Cancer (BCLC) staging system. However, the criteria for SR remain to be determined. This study compared the long-term outcome of intermediate-stage HCC patients treated by either TACE or SR as a primary treatment modality, with the aim of identifying the patient subgroup that gained a survival benefit by either modality. Methods: In total, 277 BCLC intermediate-stage HCC patients treated by either TACE (N=225) or SR (N=52) were analyzed. Results: The overall median survival time was significantly better for SR than TACE (61 vs. 30 months, P=0.002). Decision-tree analysis divided patients into seven nodes based on tumor size and number, serum alpha-fetoprotein (AFP) level, and Child-Pugh score, and these were then simplified into four subgroups (B1.B4) based on similarities in the overall hazard rate. SR provided a significant survival benefit in subgroup B2, characterized by ‘oligo’ (2.4) nodules of intermediate size (5.10 cm) when the AFP levels was <400 ng/ml, or ‘oligo’ (2.4) nodules of small to intermediate size (<10 cm) plus a Child-Pugh score of 5 when the AFP level was ≥400 ng/mL (median survival 73 vs. 28 months for SR vs. TACE respectively; P=0.014). The survival rate did not differ significantly between SR and TACE in the other subgroups (B1 and B3). Conclusions: SR provided a survival benefit over TACE in intermediate-stage HCC, especially for patients meeting certain criteria. Re-establishing the criteria for optimal treatment modalities in this stage of HCC is needed to improve survival rates. (Clin Mol Hepatol 2016;22:250-258)

Pilot Study of Heptaplatin, UFT-E and Leucovorin in Advanced Gastric Carcinoma

Sang Cheul Oh,So Young Yoon,Jae Hong Seo,Chul Won Choi,Byung Soo Kim,Sang Won Shin,Yeul Hong Kim,Si-Young Kim,Hwi Joong Yoon,Kyung Sam Cho,Jun Suk Kim 대한암학회 2003 Cancer Research and Treatment Vol.35 No.2

Original Articles : Morphologic Analysis of Water-Cooled Bipolar Radiofrequency lesions on Egg White in Vitro

( Sang Soo Kang ),( Jung Chan Park ),( Young Jun Yoon ),( Keun Man Shin ) 대한통증학회 2012 The Korean Journal of Pain Vol.25 No.3

Background: The aim of this study was to document the optimal spacing of two cannulae to form continuous strip lesions and maximal surface area by using water-cooled bipolar radiofrequency technology. Methods: Two water-cooled needle probes (15 cm length, 18-gauge probe with 6 mm electrode tip) were placed in a parallel position 10, 20, 24, 26, and 28 mm apart and submerged in egg white. Temperatures of the probes were raised from 35oC to 90oC and the progress of lesion formation was photographed every 1 minute with the increase of the tip temperature. Approximately 30 photographs were taken. The resultant surface areas of the lesions were measured with the digital image program. Results: Continuous strip lesions were formed when the cannulae were spaced 24 mm or less apart; monopolar lesions around each cannula resulted if they were spaced more than 26 mm apart. Maximal surface areas through the formation of continuous strip lesion were 221 mm2, 375 mm2, and 476 mm2 in 10, 20, and 24 mm, respectively. Summations of maximal surface area of each monopolar lesions were 394 mm2 and 103 mm2 in 26 and 28 mm, respectively. Conclusions: Water-cooled bipolar Radiofrequency technology creates continuous "strip" lesions proportional in size to the distance between the probes till the distance between cannulae is 24 mm or less. Spacing the cannulae 24 mm apart and treating about 80oC for 24 minutes maximizes the surface area of the lesion.

Poster Session:PS 1126 ; Gastroenterology (Liver) : Spontaneous Neoplastic Remission of Hepatocellular Carcinoma

( Sung Bae Kim ),( Won Seok Kang ),( Seung Hwan Shin ),( Hee Seung Lee ),( Sang Hoon Lee ),( Gi Hong Choi ),( Jun Yong Park ) 대한내과학회 2014 대한내과학회 추계학술대회 Vol.2014 No.1

We report a case of a 57-year-old male who underwent a curative resection for hepatocellular carcinoma (HCC) with histological confi rmation of spontaneously necrotized tumor. Initial serum AFP level was 4,778ng/mL. Ultrasonography demonstrated a 3. 7cm hyperechoic mass in segment 6 of the liver and dynamic contrast-enhanced liver magnetic resonance imaging showed 3. 7×3. 1cm sized HCC. He was scheduled for curative surgical resection under the clinical diagnosis of an early stage HCC (Barcelona Clinic Liver Cancer stage A). Without any intervention, the serum AFP level rapidly declined to 50 ng/mL over three weeks. He underwent curative wedge resection of segment 6 of the liver. Histology revealed a complete necrosis of the mass rimmed by infi amed fi brous capsule on a background of HBV-related cirrhosis with infi ltration of lymphoplasma cells. Exact pathophysiology underlying this event remains unknown. Among the proposed mechanisms of spontaneous neoplastic remission of HCC, circulatory disturbance and activation of host immune response offer the most scientifi c explanation for the complete histologic necrosis of HCC in the resected mass seen in our patient.