Hydrogen Behavior in Ti-Added Reduced Activation Ferritic-Martensitic Steels

Kang‑Mook Ryu,Dae Geon Lee,Joonoh Moon,Chang‑Hoon Lee,Tae‑Ho Lee,Jae Sang Lee,Dong‑Woo Suh 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.3

Hydrogen behavior and corresponding mechanical degradation were examined in TaTi-RAFM and EUROFER97 steels. Increased Ta content with Ti addition decelerates the hydrogen diffusion but increases the solubility in the lattice. It ismainly led by the higher fraction of Ta-rich MC carbides and dislocation density in TaTi-RAFM steel. Overall activationenergy of hydrogen trapping of investigated steels is evaluated to be 25.3 ~ 25.6 kJ/mol in the tempered condition. The activationenergy increases to nearly 30 kJ/mol when the steels are re-austenitized and quenched. Higher activation energy withincreased dislocation density indicates that the dislocation provides for trap site with higher activation energy than Ta-richMC carbide. Mechanical degradation by hydrogen with respect to the yield strength, tensile strength and uniform elongationcould not be observed in all investigated steels. The presence of hydrogen only has influence on the loss of post-uniformelongation. For a given charging time, the loss of post-uniform elongation is more remarkable in TaTi-RAFM steel due tothe larger hydrogen uptake.

Examining Generalizability of Kang's (1999) Model of Structural Relationship between ESL Learning Strategy Use and Language Proficiency

Kang, Sung-Woo 한국영어어문교육학회 2001 영어어문교육 Vol.7 No.2

The present study examined whether Kang's (1999) model of the relationships among language learning strategy use and language proficiency for the Asian students could e applied to a more heterogeneous group. In Kang's study, he collected information of language learning strategies of 957 foreign students learning English as a second language in American colleges through a questionnaire. He also measured the subjects' language proficiency with the Institutional Testing Program TOEFL(Test of English as a Foreign Language). This study analyzed the same data with out the limitation of cultural identity. Structural equation modeling was used to model the relationships among strategy use and language proficiency, Then, the model of the present study was descriptively compared with Kang's (1999) model for the Asian students. The overall flow of the relationship paths appeared to vary very little across the two models, which would have indicated that the generalizability of Kang's (1999) model could be extended more than originally examined. (156)

Piezoelectric Materials: All‐Solution‐Processed Flexible Thin Film Piezoelectric Nanogenerator (Adv. Mater. 45/2012)

Chung, Sung Yun,Kim, Sunyoung,Lee, Ju‐,Hyuck,Kim, Kyongjun,Kim, Sang‐,Woo,Kang, Chong‐,Yun,Yoon, Seok‐,Jin,Kim, Youn Sang WILEY‐VCH Verlag 2012 ADVANCED MATERIALS Vol.24 No.45

<P>An all‐solution‐processed flexible piezoelectric nanogenerator, composed of polycrystalline ZnO thin film and functional polymer layers such as P3HT/PCBM and PEDOT:PSS, generates energy through a mechanical rolling and muscle stretching system. On page 6022, Youn Sang Kim, Sang‐Woo Kim, and co‐workers show that this all‐solution‐processed nanogenerator is feasible as a piezoelectric patchable device and is promising for use in future energy harvesters such as wearable human patches and mobile electronics. </P>

Examining Generalizability of Kang's (1999) Model of Structural Relationships between ESL Learning Strategy Use and Language Proficiency

강성우,Kang, Sung-Woo The English Teachers Association in Korea 2002 영어어문교육 Vol.7 No.2

The present study examined whether Kang's (1999) model of the relationships among language learning strategy use and language proficiency for the Asian students could be applied to a more heterogeneous group. In Kang's study, he collected information of language learning strategies of 957 foreign students learning English as a second language in American colleges through a questionnaire. He also measured the subjects' language proficiency with the Institutional Testing Program TOEFL (Test of English as a Foreign Language). This study analyzed the same data without the limitation of cultural identity. Structural equation modeling was used to model the relationships among strategy use and language proficiency. Then, the model of the present study was descriptively compared with Kang's (1999) model for the Asian students. The overall flow of the relationship paths appeared to vary very little across the two models, which would have indicated that the generalizability of Kang's (1999) model could be extended more than originally examined. (156)

Corifollitropin alfa versus daily recombinant fsh treatment for controlled ovarian stimulation in poor responders

( Chung Hoon Kim ),( Jei Won Moon ),( Jin Young Min ),( Jun Woo Ahn ),( Sung Hoon Kim ),( Hee Dong Chae ),( Byung Moon Kang1 ) 대한산부인과학회 2014 대한산부인과학회 학술대회 Vol.100 No.-

목적: To compare the effect of long-acting recombinant FSH (rFSH), corifollitropin alfa with daily rFSH administered during 1st 7days of controlled ovarian stimulation (COS) using GnRH antagonist multiple dose protocol (MDP) in poor responders undergoing IVF/intracytoplasmic sperm injection (ICSI). 방법: In this prospective randomized study total of 90 poor responders who were scheduled for IVF/ICSI were enrolled and divided into the corifollitropin alfa group (study group) or the daily rFSH group (control group). The diagnosis of poor responder was based on the Bologna criteria of the 2011 ESHRE consensus. In all subjects, GnRH antagonist MDP was used for COS. 결과: There were no differences in patients` characteristics between the two groups. Duration of COS was comparable between the study and control groups. The numbers of oocytes retrieved and grade I or II embryos were also similar in the two groups. However, the number of mature oocytes was higher in the study group with a borderline significance (p< .07) and the ratio of mature oocytes among total oocytes retrieved was significantly higher in the study group of 78.6 ± 13.0%, compared with 61.2 ± 16.0% in control group (p< .001). There were no differences in the clinical pregnancy rate per cycle initiated, embryo implantation rate and miscarriage rate between the two groups. 결론: Corifollitropin alfa is at least as effective as daily rFSH treatment for COS using GnRH antagonist MDP, and may improve the synchrony of follicular development in poor responders undergoing IVF/ICSI. Therefore, corifollitropin alfa may be a feasible, patient-friendly alternative for poor responders.

하악 제3대구치의 존재여부 및 매복양상이 하악 우각부 골절과 과두 골절의 발생에 미치는 영향

이영주(Young-Joo Lee),송윤정(Yun-Jung Song),홍순민(Soon-Min Hong),채상식(Sang-Sik Chae),강현우(Hyeon-Woo Kang),최동주(Dong-Ju Choi),박준우(Jun-Woo Park) 대한치과의사협회 2012 대한치과의사협회지 Vol.50 No.9

Purpose : This study evaluated the impact of the presence and aspect of mandibular third molars to the mandible angle fracture or condyle fractures in Korean. Materials and Methods : A retrospective study was designed for patients attending the division of Oral and Maxillofacial Surgery, Kang-dong sacred heart hospital for treatment of mandibular fracture from January 2006 to September 2010. The primary variable was the presence of mandibular third molar and the secondary variable was the aspects of third molar impaction. Mandibular third molars were classified by the impaction depth and the available space as Pell & Gregory system. Outcome variables were the presence of mandibular angle fracture or condyle fracture. Also the source of trauma, age, sex were studied. Hospital charts, radiographs were used for study. Statistic analysis was done with descriptive statistics, the X2-test, linear-bylinear association. P value under 0.05 was considered significant statistically. Results : The number of involved patients was 86. The ratio of male to female patients was about 9:1 for angle fracture and 7:3 for condyle fracture. The most common source of trauma was assault for angle fracture and fall down for condyle fracture. The presence of mandibular third molar increased frequency of angle fracture and decreased condyle fracture with larger impaction depth. But available space of mandibular third molar did not show high association with angle or condyle fractures. Conclusion : Preventive extraction of mandibular third molar is recommended for patients with high risk of angle fracture. Male patients at their third decade or martial artists, police officer could be the case. But it is not recommended for patients with low risk of angle fracture and high risk of condyle fracture relatively. Elder female patients without any symptom on their third molar could be the case.

Construction of Stably Transformed Bm 5 Cells by Using Autographa californica Nuclear Polyhedrosis Virus IE 0 Gene

Cho, Eun Sook,Jin, Byung Rae,Sohn, Hung Dae,Choi, Kwang Ho,Kim, Soung Ryul,Kang, Seok Woo,Yun, Eun Young,Kim, Sang Hyun,Kim, Keun Young,Je, Yeon Ho,Kang, Seok Kwon 한국잠사학회 1998 한국잠사곤충학회지 Vol.40 No.2

To construct transfurmed Bm5 cells, Autographa californica nuclear polyhedrosis virus(AcNPV) IE1 gene, an immediate early viral gene was firstly used in this study. AcNPV IE1 gene, which shares on 95.3% nucleotide sequence homology with Bombyx mori nuclear polyhedrosis virus (BmNPV) IE1 gene, was isolated and cloned into pBluescript. Neomycin gene from pKO-neo was inserted under the control of the IE1 promoter to yield pAcIE1-neo. The plasmid pAcIE1-neo was transfected into Bm5 or Sf9 cells, and neomycin-resistant cells were selected in TC100 medium containing 10% fetal bovine serum (FBS) and 1 mg/ml G4l8 for two weeks. Individual clones were picked and each was amplified for further characterization. The genomic DNA from neomycin-resistant cells was isolated and characterized by PCR using AcNPV IEI gene-specific primers and by Southern blot analysis using neomycin gene probe. We concluded that AcNPV IE1 gene was functional in B. mori-derived Bm5 cells as well as Spodoptera fugjprrda-derived Sf9 cells to produce stably-transformed insect cells

Effect of Spore-forming Eumycetes on the Chemical Change of Korean Ginseng Components

Kang Wan Han(韓康完),Chang Woo Nam(南昌祐),Jae Sun Jo(曺哉銑),Sung Ki Oh(吳成基) 한국식품과학회 1981 한국식품과학회지 Vol.13 No.3

Effect of Cs₂CO₃ in Li/K and Li/Na Carbonate on the Oxygen Reduction Reaction for MCFC

Kang, Min Goo,Park, Hyun S.,Ham, Hyung Chul,Jang, Seong-Cheol,Yoon, Chang Won,Han, Jonghee,Nam, Suk Woo,Kim, Sung Hyun,Yoon, Sung Pil The Electrochemical Society 2016 Journal of the Electrochemical Society Vol.163 No.8

<P>Electrolyte properties are significantly important for the long-term stability and performance of molten carbonate fuel cells (MCFCs). The Li/Na carbonate is considered an attractive electrolyte for MCFCs due to its high ionic conductivity and low volatility. However, low oxygen solubility is a serious drawback in Li/Na carbonate electrolytes, which hinders the oxygen reduction reaction (ORR) at the MCFC cathode. Several additives have been found to enhance the oxygen solubility in alkali carbonate electrolytes. In this study, the effect of Cs2CO3 in Li/Na and Li/K carbonate mixtures was investigated by cyclic voltammetry and electrochemical impedance spectroscopy. The oxygen reduction activity improved with the increasing Cs concentration (1, 3, and 5 mol%) in all the studied carbonate melts. The addition of Cs2CO3 (5 mol%) to the Li/Na carbonate (68.0/32.0) resulted in an approximately 30% increase of the mass transfer parameter (C-0 root D-0) of the dissolved oxygen species from 0.99 x 10(-9) to 1.29 x 10(-9) mol/cm(2) s(1/2) at 620 degrees C. The changes in the ionic conductivity of the molten electrolytes with the Cs additive were also studied. (C) 2016 The Electrochemical Society. All rights reserved.</P>

Appropriate determination of the surgical transepicondylar axis can be achieved following distal femur resection in navigation-assisted total knee arthroplasty

( Sang Jun Song ),( Hyun Woo Lee ),( Kang Il Kim ),( Cheol Hee Park ) 대한슬관절학회 2021 대한슬관절학회지 Vol.33 No.-

Background: Many surgeons have determined the surgical transepicondylar axis (sTEA) after distal femur resection in total knee arthroplasty (TKA). However, in most navigation systems, the registration of the sTEA precedes the distal femur resection. This sequential difference can influence the accuracy of intraoperative determination for sTEA when considering the proximal location of the anatomical references for sTEA and the arthritic environment. We compared the accuracy and precision in determinations of the sTEA between before and after distal femur resection during navigation-assisted TKA. Methods: Ninety TKAs with Attune posterior-stabilized prostheses were performed under imageless navigation. The sTEA was registered before distal femur resection, then reassessed and adjusted after distal resection. The femoral component was implanted finally according to the sTEA determined after distal femur resection. Computed tomography (CT) was performed postoperatively to analyze the true sTEA (the line connecting the tip of the lateral femoral epicondyle to the lowest point of the medial femoral epicondylar sulcus on axial CT images) and femoral component rotation (FCR) axis. The FCR angle after distal femur resection (FCRA-aR) was defined as the angle between the FCR axis and true sTEA on CT images. The FCR angle before distal resection (FCRA-bR) could be presumed to be the value of FCRA-aR minus the difference between the intraoperatively determined sTEAs before and after distal resection as indicated by the navigation system. It was considered that the FCRA-bR or FCRA-aR represented the differences between the sTEA determined before or after distal femur resection and the true sTEA, respectively. Results: The FCRA-bR was -1.3 ± 2.4° and FCRA-aR was 0.3 ± 1.7° (p < 0.001). The range of FCRA-bR was from -6.6° to 4.1° and that of FCRA-aR was from -2.7° to 3.3°. The proportion of appropriate FCRA (≤ ±3°) was significantly higher after distal femur resection than that before resection (91.1% versus 70%; p < 0.001). Conclusions: The FCR was more appropriate when the sTEA was determined after distal femur resection than before resection in navigation-assisted TKA. The reassessment and adjusted registration of sTEA after distal femur resection could improve the rotational alignment of the femoral component in navigation-assisted TKA.