NtrC-Sensed Nitrogen Availability Is Important for Oxidative Stress Defense in Pseudomonas putida KT2440

Sujin Yeom,Jinki Yeom,박우준 한국미생물학회 2010 The journal of microbiology Vol.48 No.2

The zwf, which encodes glucose-6-phosphate dehydrogenase, is repressed by NtrC under nitrogen-limited condition. Previously, we demonstrated that induction of zwf-1 is required for protecting Pseudomonas putida cells under oxidative stress, which could be possible probably because of derepression of HexR on the zwf-1gene under oxidative stress. These findings led us investigate that NtrC still represses the zwf-1 under nitrogen-limited oxidative stress condition, which makes cells more sensitive under such condition. Interestingly, deletion of the ntrC gene significantly reduces growth rate, but renders cells more resistant to oxidative stress, under nitrogen limited condition in P. putida. More vitality of the ntrC mutant under oxidative stress condition was also confirmed by the fluorogenic redox dye using flow cytometry. The results of transcriptome analysis demonstrated that the derepression of several oxidative stress genes along with the zwf-1 gene might confer high resistance to oxidative stress in the ntrC mutant. Here, we presented the data for the first time, showing that different sets of genes are involved in nitrogen-rich and nitrogen-limited oxidative stress conditions and NtrC-sensed nitrogen availability is one of the most important prerequisite for full cellular defense against oxidative stress in P. putida.

Molecular characterization of FinR, a novel redox-sensing transcriptional regulator in Pseudomonas putida KT2440

Yeom, Sujin,Yeom, Jinki,Park, Woojun Microbiology Society 2010 Microbiology Vol.156 No.5

마이크로 λ-분기점의 주입각도가 액적 형성에 미치는 영향

염수진(Sujin Yeom),이상용(Sang Yong Lee) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.11

The effects of working fluid injection angle on the drop formation regime and size were studied at micro λ-junctions. The channel has a rectangular cross-section and the injection angle of working fluid was varied as 30, 60, 90, 120, and 150 degree. The drop formation regimes(superficial velocity ranges for drop formation) were compared depend on the injection angle. When the injection angle is 90 degree, the largest drop formation regime is observed. Thus, it is the most suitable injection angle for drop formation in our experimental ranges. Furthermore, the effect of injection angle on drop size is studied. It is observed that the drop size has its minimum value at 120 degree. However, the effect of injection angle on drop size is insignificant compared to the other variable(in this paper, channel depth). Therefore, it is concluded that the drop dispenser has the best performance(large drop formation regime) when the injection angle is 90 degree in our experimental range.

핀-관 열교환기용 분배기에서의 2상 유체 집중 압력강하에 대한 실험적 연구

염수진(Sujin Yeom),조성근(Sung Geun Jo),이상용(Sang Yong Lee) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.5

수조 비등에서 표면 특성이 CHF에 미치는 영향에 대한 연구 동향 고찰

염수진(Sujin Yeom),안상모(Sang Mo An),이승섭(Seung S. Lee),이상용(Sang Yong Lee) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11

In predicting the critical heat flux (CHF) in pool boiling systems, the contact angle between the boiling surface and the liquid and the surface roughness are considered to be the important parameters. From the microscopic viewpoint, those are affected by the micro/nano structure of the surface. Several studies have been reported on the dependence of CHF on the surface microstructure such as height and width of the cavities and distances between them. In this paper, the effects of the boiling surface characteristics on CHF are reviewed and the future research issues are discussed for better prediction of CHF.

마이크로 T-분기점에서 액적 생성시 항력계수에 관한 연구

염수진(Sujin Yeom),이상용(Sang Yong Lee) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.11

Generation of micro drops dispersed in continuous liquid flow at micro T-junction was studied through a series of experiments. The drop generation behavior was classified into three regimes based on the drop size and the location of detachment: Premature detachment, full-growth detachment Ⅰ, and full growth detachment Ⅱ. Among them, the regime of the full-growth detachment Ⅰ turned out to be stable in operation and the drag coefficient was obtained taking account of the effects of the drop geometry and wall confinement.

마이크로 T-분기점에서의 액체-액체 2상 유동의 액적 생성에 관한 연구

염수진(Sujin Yeom),이치영(Chi Young Lee),이상용(Sang Yong Lee) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.5

In the present study, generation pattern of droplets in liquid-liquid two-phase flow at a micro T-junction were classified based on the uniformity of the generated droplet sizes. We observed three different patterns of liquid droplet generation: dripping, jetting, and stratified flow. When the superficial velocity of the disperse phase is low, the dripping occurred. In this regime, droplets were highly uniform in size, determined by the balance between drag and surface tension forces. When the superficial velocity of the disperse phase became high, the stratified flow appeared. In this regime, both phases flowed in parallel without any droplet generation. The jetting phenomenon occurred as the transition regime between the dripping and the stratified flow patterns. In this regime droplets were generated by the hydrodynamic instability at the interface between two streams and their sizes were very irregular. Transition criteria between the regimes observed in the present study will be sought as a future study.

유아교사의 문제행동지도 효능감에 따른 유아의 문제행동 및 사회적 능력

염수진(Sujin Yeom),이희영(Heeyeong Lee),최태진(Taejin Choi) 부경대학교 인문사회과학연구소 2022 인문사회과학연구 Vol.23 No.3

유아교육현장의 교사들은 유아 문제행동 개선을 위해 지속적인 노력을 기울이고 있음에도 불구하고 오늘날 현장의 많은 교사들이 유아 문제행동 지도에 많은 어려움을 겪고 있다. 이와 관련하여 최근 문제행동지도 효능감이라는 새로운 개념이 소개되어 주목을 받고 있다. 이에 본 연구에서는 유아교사의 문제행동지도 효능감에 따른 유아의 문제행동 및 사회적 능력의 차이와 유아교사의 문제행동지도 효능감에 따라 차이를 보이는 구체적인 유아의 문제행동과 사회적 능력과 관련된 행동을 살펴보았다. 본 연구를 위하여 부산광역시에 소재하고 있는 유치원과 어린이집 교사 268명과 유아 1072명(교사 268명× 4명) 을 대상으로 우편발송, 직접 방문, 구글 폼 설문지, 이메일을 통해 자료를 수집하였다. 수집된 자료는 먼저 예비분석 절차로 기술통계량을 산출하였으며, 이들 변인 간 적률상관계수를 산출하였다. 다음으로 유아교사의 문제행동지도 효능감 수준에 따라 3가지 집단으로 분류하고, 이들 3개 집단 간 유아의 문제행동과, 사회적 능력 하위 변인 점수에 대하여 일원분산분석을 수행한 후 Scheffe 사후분석과 개별문항 분석을 하였다. 본 연구의 주요 결과는 다음과 같다. 첫째, 유아교사가 가진 문제행동지도 효능감의 수준에 따라서 유아의 문제행동에는 차이가 있는 것으로 나타났다. 둘째, 유아교사의 문제행동지도 효능감 수준에 따라서 유아의 사회적 능력에 차이가 있었다. 또한 본 연구에서는 각각의 개별 문항 탐색을 통하여 유아교사의 문제행동지도 효능감 수준에 따라 유의미한 차이를 보이는 구체적인 문제행동과 사회적 능력과 관련된 행동을 확인하였다. 본 연구는 선행연구에서 간과했던 유아교사가 지닌 문제행동지도 효능감의 수준에 따른 유아의 문제행동과 사회적 능력 관련 행동을 확인했다는 점에서 연구의 의의를 찾을 수 있다. 본 연구의 결과는 유아 생활지도와 관련 교사 교육의 소중한 기초자료가 될 수 있을 것으로 기대된다. Although teachers in the early childhood education field are making continuous efforts to improve the problem behaviors of young children, many teachers in the field today are having a lot of difficulty in guiding the problem behaviors of young children. In relation to this issue, a new concept which is called as problem behavior guidance efficacy has been recently introduced and attracted attention. This study attempted to investigated the difference in problem behavior and social ability of young children according to the early childhood teacher's problem behavior guidance efficacy and the specific problem behavior and social ability-related behavior of the early childhood teacher showing differences according to the problem behavior guidance efficacy of the early childhood teacher. Data were collected from 268 kindergarten and daycare center teachers and 1,072 infants (268 teachers × 4) located in Busan Metropolitan City through postal mail, direct visit, Google Form questionnaire, and e-mail. Collected data were analyzed in the following manner. First, descriptive statistics were calculated using a preliminary analysis procedure, and the moment correlation coefficients between these variables were calculated. Next, the problem behavior guidance of early childhood teachers was classified into three groups according to the level of efficacy, and one-way ANOVA was performed on the problem behaviors of young children between these three groups and the scores of the social ability sub-variables, followed by Scheffe post-hoc analysis and individual questions. analyses were performed. The main results of this study were as follows. First, there were differences in the problem behaviors of early childhood teachers according to the level of efficacy of problem behavior guidance. Second, there were differences in the social ability of children according to the level of efficacy of the early childhood teacher's problem behavior guidance. In addition, this study identified specific problem behaviors and behaviors related to social abilities that showed significant differences according to the level of effectiveness of early childhood teachers' problem behavior guidance by searching each item. This study is significant in terms of confirming problem behaviors and social ability-related behaviors of young children according to the level of efficacy of problem behavior guidance of early childhood teachers, which has been overlooked in previous studies. The results of this study are expected to be valuable basic data for early childhood guidance and related teacher education.

Native Void Space for Maximum Volumetric Capacity in Silicon-Based Anodes

Yeom, Su Jeong,Lee, Cheolmin,Kang, Sujin,Wi, Tae-Ung,Lee, Chanhee,Chae, Sujong,Cho, Jaephil,Shin, Dong Ok,Ryu, Jungki,Lee, Hyun-Wook American Chemical Society 2019 NANO LETTERS Vol.19 No.12

<P>Volumetric energy density is considered a primary factor in developing high-energy batteries. Despite its significance, less efforts have been devoted to its improvement. Silicon-based materials have emerged as next-generation anodes for lithium-ion batteries due to their high specific capacity. However, their volumetric capacities are limited by the volume expansion rate of silicon, which restricts mass loading in the electrodes. To address this challenge, we introduce porous silicon templated from earth-abundant minerals with native internal voids, capable of alleviating volumetric expansion during repeated cycles. In situ transmission electron microscopy analysis allows the precise determination of the expansion rate of silicon, thus presenting an analytical model for finding the optimal content in silicon/graphite composites. The inner pores in silicon reduce problems associated with its expansion and allow higher silicon loading of 42% beyond the conventional limitations of 13-14%. Consequently, the anode designed in this work can deliver a volumetric capacity of 978 mAh cc<SUP>-1</SUP>. Thus, suppressing volume expansion with natural abundant template-assisted materials opens new avenues for cost-effective fabrication of high volumetric capacity batteries.</P> [FIG OMISSION]</BR>

신경망을 이용한 DES 암호분석에 관한 연구

권수진(Sujin Kwon),임형신(Hyoungshin Yim),강주성(Ju-Sung Kang),염용진(Yongjin Yeom) 한국통신학회 2020 한국통신학회 학술대회논문집 Vol.2020 No.8