Cathodic electrophoretic deposition (EPD) of phenylenediamine-modified graphene oxide (GO) for anti-corrosion protection of metal surfaces

Hwang, Min-Ju,Kim, Myeong-Gi,Kim, Sanghoon,Kim, Ye Chan,Seo, Hee Won,Cho, Jung Keun,Park, In-Kyung,Suhr, Jonghwan,Moon, Hyungpil,Koo, Ja Choon,Choi, Hyouk Ryeol,Kim, Kwang Jin,Tak, Yongsug,Nam, Jae-Do Elsevier 2019 Carbon Vol.142 No.-

<P><B>Abstract</B></P> <P>Anti-corrosion metal protection of the 2D structured graphene oxide (GO) was investigated in this study using its intrinsic impermeability against reactive molecules stemming from the small geometric pore size and π-orbital repelling fields of graphene. The electrophoretic deposition (EPD) of GO sheets on metals is an attractive coating method but the negatively-charged GO only allows the anodic EPD process, which makes it difficult to achieve high-quality coating layers due to gas bubbling and electrochemical oxidation of metals. Thus, we imposed the positive charge to GO sheets using <I>p</I>-phenylenediamine (PPD) and successfully carried out the cathodic EPD in the ethanol aqueous solution. The cathodic EPD of GO on cupper provided a linear growth rate with both deposition time and voltage providing the thickness over 6.0 μm in a void-free and robust feature, which could hardly be achieved by other coating methods. Converting the GO coating to the reduced GO (RGO) by thermal reduction, we successfully increased the RGO adhesion strength up to the highest adhesion grade of 5B in the cross-cut adhesion test. An excellent anti-corrosion protection capability of the developed RGO coating was demonstrated by a decreased corrosion current density and increased corrosion potential in potentiodynamic polarization analysis.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

종교성이 폭력범죄와 재산범죄 정당화에 미치는 영향: 도덕공동체이론에 기반한 다수준적 접근

홍명기 ( Myeong-gi Hong ),차유정 ( Yoo-jung Cha ),황의갑 ( Eui-gab Hwang ) 대한범죄학회 2017 한국범죄학 Vol.11 No.2

종교가 도덕성을 사회에 제공함으로써 현대사회를 통합시키는 기능을 얼마나 수행할 수 있는지에 대한 여러 연구가 있었으나 주로 종교성과 범죄 혹은 비행 행위의 관계를 개인수준에서 다루었다. 개인수준에서의 선행연구에 더하여 본 연구는 종교가 도덕성에 미치는 영향을 사회적 맥락 속에서 설명한 도덕공동체이론을 근거로 종교다양성, 종교특성 등 국가수준 종교요인들이 폭력범죄와 재산범죄 정당화에 미치는 영향을 고려한 다수준 진단을 시도하였다. 52개국의 국제통계 자료와 70,978명에 대한 세계가치관조사자료를 통합하여 분석한 결과 개인수준에서는 신을 중요하게 생각하는 정도로 표현되는 신앙심이 높을수록 폭력범죄와 재산범죄를 정당화하는 인식이 줄어드는 영향을 보인 반면에, 종교행사참석빈도는 유의미한 영향을 미치지 않았다. 또한, 소속종교에 있어서 개신교도에 비해 유대교도와 종교가 없는 사람들의 재산범죄 정당화 정도가 높았다. 국가수준에서는 종교다양성지표(RDI)가 폭력범죄 정당화를 높이는 효과를 보임으로써 종교의 단일성이라는 사회적 맥락이 있을 때 도덕성에 미치는 종교의 효과가 크다는 도덕공동체이론에서의 주장과 일관된 결과를 확인할 수 있었다. 종교의 특성과 관련하여 도덕성을 강조하지 않는 신(Impersonal God)을 신봉하는 국가에서의 범죄 정당화 효과는 통계적으로 유의미하지 않았다. 인구밀도와 살인율 등 국가수준의 통제변인도 폭력범죄 정당화에 유의미한 영향을 미쳤다. 이러한 결과를 토대로 후속연구에 대한 시사점을 논하였다. Based on moral community thesis, this study analyzed individual-level and country-level factors of religiosity on justification of violent and property crimes. For individual-level variables, religiosity, frequency of attending religious service were considered based on the survey data gathered from 70,978 respondents as a part of the World Value Survey. As for country-level variables, total of 52 countries were analyzed with indices that represents contextual religiosity indices such as religion diversity index, type of religion(impersonal God versus personal God), etc. Results showed that individual-level religiosity had positive effects on justification of both violent and property crimes, while frequency of attending religious service did not have any significant effect. Among country level variables, Religious Diversity Index(RDI) had a positive effect on justifying violent crimes, hence supporting the moral community thesis. On the other hand, type of religion(impersonal God versus personal God) did not have statistically significant effects. Importantly, however, these country-level variables influenced people`s justification of violent and property crimes through the significant cross-level interactions with individual-level religiosity. Overall, the result implies the importance of considering the social context of religiosity in our approach to the relationship between religiosity and crime. Based on these findings, implications for policies and future research were discussed.

흡연자에서 관상동맥 내피세포 의존성 심근 혈류 예비능: H2(15)O PET 찬물자극 검사에 의한 평가

황경훈 ( Hwang Gyeong Hun ),이동수 ( Lee Dong Su ),이병일 ( Lee Byeong Il ),이재성 ( Lee Jae Seong ),이호영 ( Lee Ho Yeong ),정준기 ( Jeong Jun Gi ),이명철 ( Lee Myeong Cheol ) 대한핵의학회 2004 핵의학 분자영상 Vol.38 No.1

목적: 젊은 흡연자 및 비흡연자에게 찬물자극 후 심근혈류 예비능을 H_(2)^(15)O PET을 이용하여 측정한 후 비교함으로써 흡연에 의한 관상동맥 내피세포의 기능저하를 평가하고자 하였다. 대상 및 방법: 젊은 흡연자 9명(23.8±1.1 세; 6.6±2.5 pack-years) 및 비흡연자 9명(23.8±2.9 세)에 대하여 안정상태 및 찬물자극 후, 그리고 아데노신 주입 중에 H_(2)^(15)O를 순간주사하고 동적 PET영상을 획득한 뒤, NMF 방법으로 입력 방사능곡선 및 조직 방사능곡선을 처리하여 심근혈류량을 산출하였다. 결과: 흡연자군 및 비흡연자군 사이에 심박수혈압곱 및 안정시 혈류량에는 유의한 차이가 없었다. 그러나, 찬물자극 자극 후에는 심근혈류가 합연자군에서 비흡연가군에 비하여 유의하게 낮았으며(흡연자군 심근혈류=1.59±0.29 ml/g/min; p==0.019), 특히 안정시 심근혈류에 대한 찬물자극 후의 심근혈류의 비(내피세포 기능에 의한 심근혈류의 예비능)도 흡연자에서 유의하게 낮았다(흡연자군 = 90±24%, 비흡연자군 = 122±28% ; p=0.024). 한편, 아데노신 주입시으 심근혈류는 두군 간에 유의한 차이가 관찰되지 않았다(흡연자군 심근혈류 = 5.81±1.99 ml/g/min, 비흡연자군 심근혈류 = 5.11±1.31 ml/g/min ; p=NS). 결론: 젊은 흡연자에서 찬물자극 후에 H_(2)^(15)O PET을 이용하여 측정하여 산출한 심근혈류의 예비능이 젊은 비흡연자에 비하여 감소되어 있어서 흡연에 의한 관상동맥 내피세포의 기능장애를 확인 할 수 있었다. Purpose: Much evidence suggests long-term cigarette smoking alters coronary vascular endothelial response. In this study, we applied nonnegative matrix factorization(NMF), and unsupervised learning algorithm, to CO-less H_(2)^(15)O-PET to investigate coronary endothlial dysfunction caused by smoking noninvasively. Materials and methods: This study enrolled eighteen young male volunteers consisting of 9 smokers (23.8±1.1 yr, 6.6±2.5 pack-years) and 9 nonsmokers (23.8±2.9 yr). They do not have any cardiovascular risk factor or disease history. Myocardial H_(2)^(15)O-PET was performed at rest, during cold (5°C) pressor stimulation and during adenosine infusion. Left ventricular blood pool and myocardium were segmented on dynamic PET data by NMF method. Myocardial blood flow (MBF) was calculated from input and tissue functions by a single compartmental model with correction of partial volume and spillover effects. Results: There were no significant difference in resting MBF between the two groups (Smokers: 1.43 0.41 ml/g/min and non-smikersL: 1.37±0.41 ml/g/min; p = NS). during cold pressor Stimulation, MBF in smokers was significantly lower than that in non-smokers (1.25±0.34 ml/g/min vs 1.59±0.29 ml/g/min ; p=0.019). The difference in the ratio of cold pressor MBF to resting MBF between the two groups was also significant )p=0.024; 90±24% in smokers and 122±28% in non-smokers.). During adenosine infusion, however, hyperemic MBF did not differ significantly between smokers and non-smokers (5.81±1.99 ml/g/min vs 5.11±1.31 ml/g/min ; p=NS). Conclusion: In smokers, MBF during cold pressor stimulation was significantly lower compared with nonsmokers, reflecting smoking-induced endothelial dysfunction. However, there was no significant difference in MBF during adenosine-induced hyperemia between the two groups.

Improvement in Device Performance of Vertical Thin-Film Transistors Using Atomic Layer Deposited IGZO Channel and Polyimide Spacer

Yeo-Myeong Kim,Han-Byeol Kang,Gi-Heon Kim,Chi-Sun Hwang,Sung-Min Yoon IEEE 2017 IEEE electron device letters Vol.38 No.10

<P>Technical strategies for improving the device characteristics of the In-Ga-Zn-O (IGZO) vertical channel thin-film transistors (VTFTs) were presented and investigated. The vertical sidewall was constructed by dry-etch process and subsequently covered with IGZO, Al2O3, and AZO as active, gate insulator, and gate electrode layers by means of conformal atomic-layer-deposition. An abrupt profile and flat back-channel were achieved by employing the spin-coated polyimide (PI) spacer. The Off-current was additionally alleviated simply by cutting the area of an active layer. The fabricated IGZO VTFT using PI spacer with an 'active-cut' structure exhibited an On/off ratio of 10(3), a linear mobility of 7.1 cm(2)/Vs, and a subthreshold swing of 1.2 V/decade.</P>

Is the Oscillometric blood pressure measuring device in accord with the intra-arterial invasive blood pressure measuring method ?

Kim, Gi Hyun,Joo, Hye Jin,Lee, Won-luk,Lee, Ju-Hee,Lee, Sang Yeub,Bae, Jang-Whan,Hwang, Kyung-Kuk,Kim, Dong-Woon,Cho, Myeong-Chan 충북대학교 의과대학 충북대학교 의학연구소 2010 忠北醫大學術誌 Vol.20 No.1

Purpose: Hypertension is closely related to the occurrence and aggravation of major incidents in cardiovascular system. However, there is not much elucidated about the accordance of blood pressure (BP) measurement with oscillometric device and invasice BP from patients having the risks of cardiovascular disease. We have checked the accordance of non-invasive BP using the oscillometric device in comparison with invasive BP through redial artery catheter in performing coronary angiography. Subjects and methods: We compared the BP measured through redial artery and electronic sphygomanometer (Omron HEM-747IC, Japan) from the brachial for 104 patients who had gone through coronary artery angiography by visiting Chungbuk university hospital from September, 2007 till April, 2008. Results: The BP measured with oscillometric device was mostly in accordance with invasive BP for all systolic, diastolic and average BP. However, the group of stage 1 hypertension by the standards of Seventh Report of the Joint National Committee showed low accordance between the two methods in diastolic BP. For non hypertension group and pre-hypertension group, systolic BP showed a pattern where systolic BP was underestimated, but for the first and second stage hypertension groups, the BP measured with oscillometric device displayed an overestimated patten Conclusion: Most of the blood pressures measured with automated sphygomanometer showed good agreement with invasive BP. However, it needs attention in using because the diastolic BP is not in accordance with invasive BP form the first stage hypertension patients. 연구 목적 : 고혈압은 심혈관계 주요사건 발생과 악화에 밀접한 관계가 있다. 그러나 아직까지 심혈관 질환의 위험성을 가진 환자에서 전자 혈압계를 통한 혈압 측정과 침습적 혈압과 일치여부에 대해서 잘 밝혀진 바가 없다. 우리는 관상동맥 조영술을 실시하면서 노동맥 도관을 통한 침습적 혈압과 비교하여 전자열합계를 이용한 비침급적 혈압의 일치도를 확인하였다. 대상 및 방법 : 2007년 9월부터 2008년 4월까지 충북대학교 병원을 방문하여 관상동맥 조영술을 시행 받은 104명의 환자들을 대상으로 노동맥을 통한 혈압 측정과 상완에서 전자 혈압계 (Omron HEM-747IC, 일본)로 측정한 혈압을 비교하였다. 결과 : 자동 혈압계로 측정한 혈압은 대체로 수축기, 확장기 및 평균 혈압 모두 침습적 혈압 값과 일치하였다. 그러나 Seventh Report of the Joint National Committee 기준으로 1단계 고혈압을 갖는 집단은 이완기 혈압이 저평가되는 양상을 보였으니 1단계 및 2단계 고혈압 군에서는 자동 혈압계로 측정한 혈압이 고평가되었다. 확장기 혈압 및 평균 혈압은 모든 단계에서 고평가 되는 양상을 보였다. 결론 : 자동 혈압계로 측정한 혈압의 대부분은 침습적 혈압과 좋은 일치도를 보인다. 그러나 1단계 고혈압 환자군에서는 확장기 혈압이 침습적 혈압과 일치하지 않으므로 사용에 주의가 필요하겠다.

매설형 삭마 깊이 계측용 센서 개발

김명기(Myeong-Gi Kim),김상우(Sang-Woo Kim),함희철(Heecheol Ham),황태경(Tae-Kyung Hwang) 한국항공우주학회 2022 한국항공우주학회 학술발표회 논문집 Vol.2022 No.4

Preoperative left portal vein embolization for left liver resection in high-risk hepatobiliary malignancy patients

Shin Hwang,Gi-Won Song,Gi-Young Ko,Dong-Il Gwon,Myeong-Hwan Kim,Sung-Koo Lee 한국간담췌외과학회 2016 한국간담췌외과학회 학술대회지 Vol.2016 No.4

실시간 삭마 깊이 계측용 센서 통전 실험

김명기(Myeong-Gi Kim),김상우(Sang-Woo Kim),함희철(Heecheol Ham),황태경(Tae-Kyung Hwang) 한국항공우주학회 2020 한국항공우주학회 학술발표회 논문집 Vol.2020 No.7

복싱선수들의 체중감량 시 블랙초코베리 섭취가 과산화 지질과 항산화 효소 및 면역기능에 미치는 영향

황영철(Hwang, Young-Chul),박상서(Park, Sang-Seo),이성환(Lee, Sung-Hwang),김경태(Kim, Kyung-Tea),김준희(Kim, Jun-Hee),김보경(Kim, Bo Kyung),정석률(Jung, Suk-Yool),김명기(Kim, Myeong-Gi),심영제(Sim, Young-Je) 한국사회체육학회 2014 한국사회체육학회지 Vol.0 No.58

Present study is to investigate an impact of black chokeberry on the lipid peroxidation, antioxidant enzymes and immunity for boxers while they are trying to loose weight1. 3male boxers are subjected to two weeks of weight reduction training, assigned randomly in two groups : an experimental group taking the black chokeberry and the placebo group. The impact on the lipid peroxidant enzymes and immunity are as the followings: 1. There was no significant difference in MDA concentration in blood between the two groups during two weeks of weight reduction training while the experimental group showed a significant difference in MDA concentration after the training by decrease(p<.05) 2. There was no significant difference in GPX concentration in blood between the experimental control groups. 3. There was no significant difference in immune globlin(IgG, IgA, IgM)between the two groups in two weeks while the experimental group showed a significant difference in IgA concentration in blood after the training by increase(p<.05). Therefore, two weeks of antioxidant intake dose not make any significant difference between two groups, however, since the experimental group taking the black chokeberry showed a slightly significant decrease in MDA and a slightly significant increase in IgA indicated that taking antioxidant while under a intense training and weight reduction can be performance enhancing for athletes.

THE DESIGN AND IMPLEMENTATION OF EFFICIENT NATIVE PROCESSING MODULE TO IMPROVE SPEED OF INTERACTIVE DTV MIDDLEWARE

Dong-Gi Im,Cheul-Jun Hwang,Sang-Myeong Shin,Min-Soo Jung 한국멀티미디어학회 2006 한국멀티미디어학회 국제학술대회 Vol.2006 No.-

In recent years, interactive TV(ITV) has become the "next big thing" for the broadcasting industry as broadcasters and network operators seek new ways of making money and keeping viewers watching. The development of efficient ITV middleware is essential by the reason. However, the main concern of ITV middleware is now its low execution speed caused by the hardware limitation. In this paper, we propose several ideas about how to improve an execution speed of ITV middleware by an added Java Native Interface APIs and concurrent native modules. With our approach, the execute time of native thread module reduced by 32% and 60%.