Effect of Asymmetric Hot Rolling on the Texture Evolution of Fe–3%Si Steel

Tae‑Wook Na,Hyung‑Ki Park,박창수,Hyung‑Don Joo,Jong‑Tae Park,Heung Nam Han,Nong‑Moon Hwang 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.6

In Fe–3%Si steel, the hot rolling process affects not only the hot rolling texture but also the primary recrystallization texture. Here, the effect of asymmetric hot rolling was studied by comparing the difference in the texture evolved between asymmetricand symmetric hot rolling. The effect of asymmetric hot rolling on the texture of primary recrystallized Fe–3%Si steel wasalso studied. The symmetric hot rolling of Fe–3%Si steel produces a rotated cube texture at the center but Goss and coppertextures near the surface. Asymmetric hot rolling tends to produce Goss and copper textures even at the center like thetexture near the surface. After primary recrystallization, the dominant texture at the center changes from {001} <210> to{111} <112> and the new texture has a higher fraction of the grains which make the low energy boundary with Goss grainsthan that of symmetric hot rolling.

Misorientation Characteristics at the Growth Front of Abnormally-Growing Goss Grains in Fe–3%Si Steel

Tae‑Young Kim,Tae‑Wook Na,Hyung‑Seok Shim,Yong‑Keun Ahn,Yong‑Kwon Jeong,Heung Nam Han,Nong‑Moon Hwang 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.12

Penetrating morphologies at the growth front of abnormally-growing Goss grains in Fe–3%Si steel was examined in view ofthe possibility that they are the two-dimensional section of the solid-state wetting (SSW) along the triple junction line. Toobtain the statistically meaningful data, 102 penetrated grain and 204 penetrating abnormally-growing Goss grain morphologieswere examined. The misorientation angles of penetrating and penetrated grains were measured by electron backscattereddiffraction. Among the 102 examined penetrated grain boundaries, none has low misorientation angles less than 15°,whereas 17.2% of the 204 penetrating grain boundaries have low misorientation angles, and 23.5% of them have coincidencesite lattice boundaries. Besides, boundary energies of penetrating Goss grains, which were estimated from misorientationangles of the three grains in the penetrating morphology, satisfied the energetic condition for SSW along the triple junctionline. These results imply that the abnormal grain growth of Goss grains in Fe–3%Si steel occurs by the mechanism of subboundaryenhanced SSW.

Poster Session : PS 0831 ; Upper GI Tract : Clinical Factors to Predict Angiographically Detectable Non-Variceal Upper Gastrointestinal Bleeding in Patients Refractory to Endoscopic Treatment

( Tae Hwan Ha ),( Tae Hoon Oh ),( Sung In Yu ),( Min Kim ),( Jong Wook Kim ),( Won Ki Bae ),( Jae Hyung Kim ),( Seung Suk Baek ),( Mi Jin Ryu ),( Ye Na Choi ),( Ji Young Park ),( Eileen L Yoon ),( Tae 대한내과학회 2014 대한내과학회 추계학술대회 Vol.2014 No.1

Background: Non-variceal upper GI bleeding (NVUGIB) is a common medical problem that has signifi cant association with morbidity and mortality. Angiographic detection and subsequent transarterial embolization (TAE) is a primary treatment option when medical and endoscopic treatments fail. We investigated clinical factors that could affect the success of the angiographic detection and prognosis after TAE in patients with NVUGIB refractory to endoscopic therapy. Methods: A retrospective analysis of the clinical data was done in patients with failed endoscopic treatment who underwent angiography for the treatment of acute NVUGIB between May 2002 and May 2013. Patients were divided into detection or non-detection groups according to the presence of bleeding stigmata in angiographic fi nding. Rebleeding defi ned as subsequent bleeding event within 7 days and mortality within 30days were analyzed as outcome parameters after TAE following detection in angiography. Results: A total 45 patients 37 (male, mean age, 65.9±14.9 years) were analyzed and classifi ed as a detection group (n=25, 55.5%) and non-detection group (n=20, 44.6%). Peptic ulcers were the most common cause of refractory NVUGIB. Larger transfusion amount (5.7±3.9 unit vs. 3.5±2.8 unit; P=0.03), prolonged aPTT level (34.2±17.3 sec vs. 21.8±13.8 sec; P=0.01) and short time interval between last endoscopy and angiography (17.5±25.9 hours vs. 34.3±59.5 hours; P=0.04) were found to be signifi cant factors for predicting angiographic detection. TAE was performed in all patients detected in angiography. Rebleeding (44%) was significantly associated with higher Rockall score (8.3±1.5 vs. 6.6±2.4; P=0.046) and mortality (12%) was signifi cantly associated with higher Rockall score (9.3±0.6 vs. 7.1±2.2; P=0.002) and higher level of BUN (55.3±47.4 vs. 27.6±17.4; P=0.01). Conclusions: Clinical characteristics associated with angiographic detection in patients with NVUGIB refractory to endoscopic therapy were severe bleeding, bleeding tendency and early angiographic intervention. The Rockall score is useful parameter for predicting rebleeding and mortality after TAE.

만화 과제를 이용한 정신분열병 환자의 사회인지 능력의 측정

오정은,나명현,하태현,신용욱,노규식,홍순범,이경진,신민섭,이영호,권준수 大韓神經精神醫學會 2005 신경정신의학 Vol.44 No.3

Objectives : This study is to investigate the hypothesis that schizophrenic patients have difficulty in inferring mental state of others. Methods : Twenty schizophrenic patients and twenty normal subjects were administered to the Cartoon Task required inferring the character's intention in a given context. Results : The schizophrenic patients showed a statistically significant impairment in the Cartoon Task. Both groups chose the card depicting a frequent everyday action significantly more rather than the similar card to the last picture in each story for wrong answers. Conclusion : These preliminary results suggest that schizophrenia is associated with a specific deficit of the cognitive ability referred to as social cognition, and this deficit can be detected not only in the acute phase as found in previous research studies, but also in remission. Also when subjects fail to appreciate what is going on in the minds of other people, they seem to rely on a socially familiar experience.

정신분열병에 대한 리스페리돈의 효과 및 안정성

이민수,김용구,김영훈,연병길,오병훈,윤도준,윤진상,이철,정희연,강병조,김광수,김동언,김명정,김상훈,김희철,나철,노승호,민경준,박기창,박두병,백기청,백인호,손봉기,손진욱,양병환,양창국,우행원,이정호,이종범,이홍식,임기영,전태연,정영조,정영철,정인과,정인원,지익성,채정호,한상익,한선호,한진희,서광윤 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.1

연구목적 : 본 시험의 목적은 임상시험 시작전에 연구자들을 대상으로 PANSS Workshop을 통하여 PANSS, ESRS에 대한 국내에서의 표준화 작업을 구축하고 새로운 정신병 치료제인 리스페리돈의 효과와 안정성을 재확인하여 리스페리돈 사용에 대한 적정화를 이루는데 있다. 연구방법 : 1996년 4월부터 1996년 9월까지 국내 39개 대학병원 정신과에 입원중인 혹은 증상이 악화되어 입원하는 정신분열병 환자 377명을 대상으로 다시설 개방 연구를 시행하였다. 1주일간의 약물 배설기간을 가진후, 리스페리돈을 8주간 투여하였고, 기준점, 1주, 2주, 4주, 그리고 8주후에 평가되었다. 용량은 제1일에는 리스페리돈 1mg씩 1일 2회, 제2일에는 2mg씩 1일 2회, 제3∼7일에는 3mg씩 1일 2회 투여하였다. 이후 환자의 임상상태에 따라 임의로 증량할 수 있으며, 최대 일일 16mg을 초과하지 않도록 하였다. 추체외로 증상을 조절하기 위한 투약을 허용하였다. 임상증상 및 부작용의 평가는 PANSS(Positive and Negative Syndrome Scale), CGI(Clinical Global Impression) 그리고 ESRS(Extrapyramidal Symptom Rating Scale)을 사용하였다. 연구결과 : 377명중 343명(91%)이 8주간의 연구를 완결하였다. 치료 종결시점인 8주후 PANSS 총점수가 20% 이상 호전된 경우를 약물 반응군으로 정의할때, 약물반응군은 81.3%였다. 리스페리돈에 반응하는 예측인자로는 발병연령, 이전의 입원 횟수, 유병기간이 관련 있었다. 리스페리돈은 1주후부터 PANSS양성, 음성, 및 일반정신병리 점수상에 유의한 호전을 보여 효과가 빨랐다. CGI의 경우도 기준점에 비해 1주후부터 유의한 감소를 나타내었다. ESRS의 경우, 파킨슨 평가점수는 기준점과 비교해 투여 1주, 2주, 4주후 유의하게 증가되었다가 8주후 기준점과 차이가 없었다. Dystonia 평가점수는 1주후만 유의한 증가를 보였으며, dyskinesia 평가점수는 유의한 차이가 없었다. 혈압, 맥박수의 생명징후 및 일반 혈액학 검사, 생화학적 검사, 심전도 검사에서 유의한 변화는 없었다. 결 론 : 이상의 다시설 개방 임상 연구를 통해 리스페리돈은 정신분열병 환자에서 양성증상뿐만 아니라 음성증상 및 전반적인 증상에도 효과적인 것으로 사료된다. 보다 명확한 평가를 위해서는 다른 항정신병약물과의 이중맹검 연구가 필요할 것으로 생각되며, 또한 장기적 치료에 대한 평가도 함께 이루어져야 하겠다. Objective : The purpose of this study was to investigate the efficacy and safety of risperidone in the treatment of Korean schizophrenic patients. Method : This multicenter open study included 377 schizophrenic patients drawn from 39 university hospitals. After a wash-out period of 1 week, the schizophrenic patients were treated with risperidone for 8 weeks and evaluated at 5 points ; at baseline, and 1, 2, 4 and 8 weeks of treatment. The dose was increased from 2mg/day(1mg twice daily) to 6mg/day(3mg twice daily) during the first week and adjusted to a maximum of 16mg/day over the next 7 weeks according to the patient's clinical response. Medication to control extrapyramidal symptoms was permitted. The psychiatric and neurological status of the patients was assessed by PANSS, CGI, and ESRS scales. Results : 343(91%) of 377 patients completed the 8-week trial period. Clinical improvement, as defined by a 20% or more reduction in total PANSS score at end point, was shown by 81.3% of patients. The predictors of response to risperidone were associated older age, shorter duration of illness, fewer previous hospitalization. Risperidone had rapid onset of action ; a significant decrease of the total PANSS and three PANSS factor(positive, negative, general), and CGI was already noticed at the end of first week. For the ESRS, parkinsonism rating scores were significantly increased until week 4 comparing with baseline. Dystonia rating scores were significantly increased until week 1, and dyskinesia rating scores were not significantly changed during the study. Laboratory parameters including vital sign, EKG, hematological, and biochemical values showed no significant changes during the trial. Conclusions : This study suggests that risperidone is generally safe and effective against both the positive and negative symptoms in our group of patients.

Comparison of three-dimensional morphologies of abnormally growing grains between Monte Carlo simulations and experiments of Fe-3% Si steel

Na, Tae-Wook,Cho, Da-Hee,Park, Chang-Soo,Park, Jong-Tae,Han, Heung Nam,Hwang, Nong-Moon Elsevier 2018 Materials characterization Vol.144 No.-

<P><B>Abstract</B></P> <P>Three-dimensional (3-D) Monte Carlo simulations of grain growth with sub-boundaries in the presence of precipitates were performed based on the distribution of realistic grain boundary energy data. The simulated grains with sub-boundaries grew abnormally. The simulated and experimental morphologies of the abnormally growing grains in Fe-3%Si steel were compared. The experimental 3-D morphology was reconstructed from serially sectioned images. Both the simulated and experimental 3-D morphologies of abnormally growing grains have highly irregular and complicated shapes whereas both the simulated and experimental 3-D morphologies of normally growing grains have relatively regular and simple shapes. Growth by wetting is responsible for the highly irregular shape of the experimental abnormally growing grains of Fe-3%Si steel as well as for the highly irregular shape of the simulated abnormally growing grains.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Grains with sub-boundaries grew abnormally in the MC simulation with realistic grain boundary energy. </LI> <LI> The experimental 3-D morphology of Goss grain was reconstructed from serially sectioned images. </LI> <LI> 2-D sectioned microstructures of the MC simulation and experiment have highly irregular shape. </LI> <LI> Both simulated and experimental 3-D morphologies of AGG have similar complicated shapes. </LI> </UL> </P>

Effect of laser power on oxygen and nitrogen concentration of commercially pure titanium manufactured by selective laser melting

Na, Tae-Wook,Kim, Won Rae,Yang, Seung-Min,Kwon, Ohyung,Park, Jong Min,Kim, Gun-Hee,Jung, Kyung-Hwan,Lee, Chang-Woo,Park, Hyung-Ki,Kim, Hyung Giun Elsevier 2018 Materials characterization Vol.143 No.-

<P><B>Abstract</B></P> <P>This study analyzed the variation of mechanical properties and its causes with increasing the laser power in the fabrication of pure titanium by selective laser melting (SLM). SLM samples were fabricated using commercially pure titanium grade 1 powder when the scan speed was 1000 mm/s and the laser power as 120, 200, 280, 360, and 440 W, respectively. As the laser power increased, the hardness and strength of the samples increased gradually. During the SLM processing, the concentrations of oxygen and nitrogen in the SLM samples were increased, which resulted in the increase of hardness and strength. The SLM equipment used in this study removed oxygen in the chamber by flowing high purity argon gas and fabricates the sample while preserving the oxygen concentration in the atmosphere to 0.2%. Evaluating the possibility of oxidation and nitriding during the SLM process by thermodynamic analysis, it was found that the process occurred under conditions in which temperature and residual oxygen and nitrogen partial pressure led to oxidation and nitriding.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The hardness and strength of pure titanium fabricated by SLM were increased with increasing the laser power. </LI> <LI> During the SLM processing, the concentrations of oxygen and nitrogen in the SLM parts were increased. </LI> <LI> The oxidation and nitriding were thermodynamically possible under SLM. </LI> </UL> </P>

Misorientation angle analysis near the growth front of abnormally growing grains in 5052 aluminum alloy

Na, Tae-Wook,Park, Hyung-Ki,Park, Chang-Soo,Park, Jong-Tae,Hwang, Nong-Moon Elsevier 2016 Acta materialia Vol.115 No.-

<P>Misorientation measurements at the growth front of abnormally growing grains in 5052 aluminum alloy were made using electron back-scattered diffraction (EBSD). When a three-dimensional morphology of solid-state wetting along a triple junction line is observed on a two-dimensional section, two kinds of morphologies could be observed. One is a morphology of penetrating the grain boundary when the section is parallel to the triple junction line. The other is morphology of a three or four-sided grain with a negative grain boundary curvature when the section is vertical to the triple junction line. Many morphologies of penetrating the grain boundary were observed at the growth front of abnormally growing grains. Grain boundary energies, which were estimated from misorientation measurements of the three grains in the penetrating morphology, satisfied the energetic condition for wetting along the triple junction line. Misorientation measurements showed that some matrix grains away from the growth front of abnormally growing grains had the same crystallographic orientation as that of the abnormally growing grain. Repeated EBSD measurements on each serial section show that these grains were actually identical to the abnormally growing grain, being connected three dimensionally. These results imply that the abnormal grain growth in 5052 aluminum alloy occurs by the mechanism of sub-boundary enhanced solid-state wetting. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.</P>

Genome-Wide Association Study for Cold Tolerance in Rice Seedlings under Cold-Water Treatment

( Na-eun Kim ),( Soon-wook Kwon ),( Jeonghwan Seo ),( Tae-ho Ham ),( Joohyun Lee ) 한국육종학회 2021 Plant Breeding and Biotechnology Vol.9 No.4

Rice is a temperature-sensitive crop, its yield is severely affected by low temperature, especially cold stress at the seedling stage will delay heading. To understand the genetic basis of cold tolerance, we evaluated the cold tolerance at the seedling stage of 136 rice accessions. To evaluate cold tolerance, we treated rice seedlings with cold water irrigation for ten days and scored the cold tolerance on a 1-9 scale, based on their low-temperature response and subsequent recovery. The genome-wide association study for cold tolerance revealed seven QTLs on chromosomes 1, 3, 6, 7, 10, and 12. The genomic region of the qCWS7 on chromosome 7 overlapped with a previously reported QTL associated with cold tolerance in the germinating stage. Similarly, qCWS1-1, qCWS1-2, qCWS3, qCWS6, and qCWS10 overlapped with a previously reported QTL associated with drought-stress tolerance. Subsequent bioinformatic and haplotype analyses suggested that five candidate genes affect cold tolerance: Os01g0228600 encoding a cytosolic hydroxypyruvate reductase, Os03g0115000 encoding a cupredoxin domain containing protein, Os06g0612800 encoding a stress-associated protein (SAP) gene family, Os12g0552500 encoding a universal stress protein (USP), and Os10g0482900 encoding a thioredoxin fold domain containing protein.

Evolution of nanomorphology and anisotropic conductivity in solvent-modified PEDOT:PSS films for polymeric anodes of polymer solar cells

Na, Seok-In,Wang, Gunuk,Kim, Seok-Soon,Kim, Tae-Wook,Oh, Seung-Hwan,Yu, Byung-Kwan,Lee, Takhee,Kim, Dong-Yu The Royal Society of Chemistry 2009 Journal of materials chemistry Vol.19 No.47

<p>A highly conductive poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) film, obtained by addition of a polar solvent, dimethylsulfoxide (DMSO), to an aqueous solution of PEDOT:PSS, was thoroughly investigated to gain a deeper understanding of the fundamental characteristics of the solvent-modified PEDOT:PSS film. Use of the DMSO-modified PEDOT:PSS film as a transparent anode to achieve low-cost and high-efficiency ITO-free organic solar cells (OSCs) based on poly(3-hexylthiophene) (P3HT) and 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)C<SUB>61</SUB> (PCBM) was also examined. Changes in the conductivity, morphology, surface composition, work-function, and anisotropic conductivity in both the parallel and perpendicular directions of solvent-treated PEDOT:PSS films that resulted from the addition of various amounts of DMSO were investigated to better understand the nature of the solvent-modified PEDOT:PSS film and the origin of its dramatically enhanced conductivity. Furthermore, the effects of using the modified PEDOT:PSS films as polymer anodes on solar cell performance were investigated by addition of various amounts of DMSO and by the use of PEDOT:PSS films with different thicknesses. The ITO-free OSCs with optimized PEDOT:PSS anodes had a high power conversion efficiency that was comparable to that of conventional ITO-based devices.</p> <P>Graphic Abstract</P><P>Highly conductive PEDOT:PSS films were thoroughly investigated for a deeper understanding of solvent-modified PEDOT:PSS films and their use as transparent anodes of polymer solar cells. <img src='http://pubs.rsc.org/ej/JM/2009/b915756e/b915756e-ga.gif'> </P>