Hierarchically nanoporous pyropolymer nanofibers for surface-induced sodium-ion storage

Yoon, Hyeon Ji,Lee, Min Eui,Kim, Na Rae,Yang, Seung Jae,Jin, Hyoung-Joon,Yun, Young Soo Pergamon Press 2017 Electrochimica Acta Vol. No.

<P><B>Abstract</B></P> <P>Surface-driven charge storage materials based on both electrochemical double layer (EDL) formation and pseudocapacitive behavior can deliver high energy and power capabilities with long-lasting cycling performance. On the other hand, the electrochemical performance is strongly dependent on the material properties, requiring sophisticated electrode design with a high active surface area and a large number of redox-active sites. In this study, hierarchically nanoporous pyropolymer nanofibers (HN-PNFs) were fabricated from electrospun polyacrylonitrile nanofibers by simple heating with KOH. The HN-PNFs have a hierarchically nanoporous structure and an exceptionally high specific surface area of 3,950.7m<SUP>2</SUP> g<SUP>−1</SUP> as well as numerous redox-active heteroatoms (C/O and C/N ratio of 10.6 and 16.8, respectively). These unique material properties of HN-PNFs resulted in high reversible Na-ion capacity of ∼292mAhg<SUP>−1</SUP> as well as rapid kinetics and stable cycling performance in the cathodic potential range (1-4.5V vs. Na<SUP>+</SUP>/Na). Furthermore, energy storage devices based on HN-PNFs showed a remarkably high specific energy of ∼258 Wh kg<SUP>−1</SUP> at ∼245Wkg<SUP>−1</SUP> as well as a high specific power of ∼21,500Wkg<SUP>−1</SUP> at ∼78 Wh kg<SUP>−1</SUP>, with long and stable cycling behaviors over 2,000 cycles.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Hierarchically nanoporous pyropolymer nanofibers (HN-PNFs) were fabricated. </LI> <LI> HN-PNFs have a high specific surface area of ∼3,950m<SUP>2</SUP> g<SUP>−1</SUP> and numerous heteroatoms. </LI> <LI> HN-PNFs exhibit high capacities of ∼292mAhg<SUP>−1</SUP> and great rate/cycling performances. </LI> <LI> High energy (258Whkg<SUP>−1</SUP>) and high power (21,500Wkg<SUP>−1</SUP>) are achieved. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Hierarchically nanoporous pyropolymer nanofibers (HN-PNFs) fabricated from electrospun polyacrylonitrile nanofibers by simple heating with KOH exhibited high electrochemical performance for Na-ion storage.</P> <P>[DISPLAY OMISSION]</P>

실시간 홀로그래픽 간섭법을 이용한 압력기용기의 내부결함 측정법

姜永準,羅義均 全北大學校 1995 論文集 Vol.40 No.-

Conventional measurement methods using ultrasonic wave or x-ray, eddy current for non-destructive testing(NDT) in nuclear power plants and other industrial plants have been performed as the method of contact with objects to be inspected. With this reason these methods have been taken relatively much time and the inspected area is limited by the location of probe or film. But holographic interferometry which is a non-contact optical measurement method using a coherent light source has an advantage that the quantitative measurement can be performed at a time. In this paper a new method using realtime golographic interferometry and image processing for detecting internal flaws of pressure vessels is presented.

질산화 작용이 있는 Aeromonas hydrophila의 동정 및 특성

엄미나,장재철,유영희,지의상 한국식품영양학회 2000 韓國食品營養學會誌 Vol.13 No.6

폐수처리 중 생물학적 처리에 활용할 수 있는 질소분해 능력을 가진 미생물을 분리하여 동정하고자 경기도내 하천 6지점에서 채취한 시료로부터 50개 균주를 선별하였다. 형태학적, 생화학적 및 배양학적 실험결과 Bergey's mannual of systematic bacteriology의 색인을 통하여 Aeromonas hydrophila로 동정하였다. Aeromonas hydrophila(AH-1). (AH-3), (AH-4), (AH-6) 균이 질산화 능력이 우수하였다. 4개 균주 모두 amoxillin, ampicillin, cephalothin과 ticarcillin에 내성을 나타내었다. 본 실험에서 분리한 .Aeromonas hydrophila의 질산화의 최적조건은 균 농도 1.0×l0exp(6) cells/ml, 배양온도 37℃로 나타났다. For the purpose of the isolation of microorganisms which have the capability of nitrification, we isolated the microorganisms in 6 samples collected from the stream of Kyonggi area. 60 strains were isolated. The selected strain were identified as a Aeromonas hydrophila based on the data obtained from the morphological, biochemical and cultural characteristics defined experiments. Among them Aeromonas hydrophila (AH-1), (AH-3), (AH-4), (AH-6) showed the highest nitrification capability. All isolates were resistant to amoxillin, ampicillin, cephalothin and ticarcillin. Optimum culture conditions of isolates were 37℃ and 1×10exp(8) cells/ml for 4 hours in the nitrate medium.

열공형과 비열공형 피질하 혈관성 치매에서 위험인자의 차이에 관한 비교 연구

배희준,정지향,유경호,나덕렬,김상윤,최경규,양동원,손의주,이상도,김재우,박경원,김응규,이재홍,박미영,한일우,함동석,최문성,하충건,최성혜,이애영,이병철,한설희 대한치매학회 2003 Dementia and Neurocognitive Disorders Vol.2 No.2

Backgrounds and Objectives: Vascular dementia is a group of dementing disoders arising from various stroke syndrome. Among these. subcortical ischemic vascular dementia (SIVD) is regarded as a relatively distinct clinical entity. However, MRI patterns of SIVD are not homogenous. In some patients, lacunes are dominant, and in others, subcortical white matter changes are. This study was designed to compare risk factor profiles between SIVD with and without multiple lacunes. Methods: We divided 47 subjects (22 males, mean age. 68 years) recruited from VADAPET (Multicenter Trial For Evaluation Of The Changes In the PET Images Of Subcortical Vascular Dementia Patient) study into two groups one with more than 5 lacunes in deep gray matter (lacune group) and the other with 5 or less(non-lacune group) Clinical characteristics and laboratory findings of two groups were compared. Results: Nineteen of 47 patients (40%) belonged to the lacune group. The lacune and non-lacune groups d d not differ in the following variables: age, hypertension, diabetes mellitus, hyperlipidemia heart disease, history of stroke or TIA, history of trauma or major surgery, family history of hypertension stroke, or dementia, age at diagnosis of dementia, body mass index, white blood cell count, ESR, CRP, fibrinogen, hemoglobin A1C, total cholesterol. LDL cholesterol creatinine, proteinuria, glucosuria, and microhematuria. However, male sex, smoking alcohol. hemoglobin, and HDL cholesterol were possibly associated more with lacune group SIVD than with non-lacune group (p<0 1) Multivariate analyses revealed that smoking, hemoglobin, and HDL cholesterol were independent predictors of SIVD with multiple lacunes Conclusion: Our study suggests that SIVD with multiple lacunes may be significantly different in smoking habits hemoglobin, and HDL cholesterol from SIVD without multiple lacunes.

Real-time sitting posture monitoring system based on random forest using pressure sensor array

Eui-Jin Koo(구의진),Seung-Hyeon Lee(이승현),Da-Young Go(고다영),Gi-Na Yoon(윤지나),Min-Seon Lee(이민선),Ah-Young Jung(정아영),Han-Hee Lee(이한희),Jun-Chang Yang(양준창),Steve Park(스티브박),Young-Jin Na(나영진),Soo-Young Kim(김수영),W 대한기계학회 2023 대한기계학회 춘추학술대회 Vol.2023 No.4

Considerations of Environmental Factors Affecting the Detection of Underwater Acoustic Signals in the Continental Regions of the East Coast Sea of Korea

Na, Young-Nam,Kim, Young-Gyu,Kim, Young-Sun,Park, Joung-Soo,Kim, Eui-Hyung,Chae, Jin-Hyuk The Acoustical Society of Korea 2001 韓國音響學會誌 Vol.20 No.e2

This study considers the environmental factors affecting propagation loss and sonar performance in the continental regions of the East Coast Sea of Korea. Water mass distributions appear to change dramatically in a few weeks. Simple calculation with the case when the NKCW (North Korean Cold Water) develops shows that the difference in propagation loss may reach in the worst up to 10dB over range 5km. Another factor, an eddy, has typical dimensions of 100-200km in diameter and 150-200m in thickness. Employing a typical eddy and assuming frequency to be 100Hz, its effects on propagation loss appear to make lower the normal formation of convergence zones with which sonars are possible to detect long-range targets. The change of convergence zones may result in 10dB difference in received signals in a given depth. Thermal fronts also appear to be critical restrictions to operating sonars in shallow waters. Assuming frequency to be 200Hz, thermal fronts can make 10dB difference in propagation loss between with and without them over range 20km. An observation made in one site in the East Coast Sea of Korea reveals that internal waves may appear in near-inertial period and their spectra may exist in periods 2-17min. A simulation employing simple internal wave packets gives that they break convergence zones on the bottom, causing the performance degradation of FOM as much as 4dB in frequency 1kHz. An acoustic experiment, using fixed source and receiver at the same site, shows that the received signals fluctuate tremendously with time reaching up to 6.5dB in frequencies 1kHz or less. Ambient noises give negative effects directly on sonar performance. Measurements at some sites in the East Coast Sea of Korea suggest that the noise levels greatly fluctuate with time, for example noon and early morning, mainly due to ship traffics. The average difference in a day may reach 10dB in frequency 200Hz. Another experiment using an array of hydrophones gives that the spectrum levels of ambient noises are highly directional, their difference being as large as 10dB with vertical or horizontal angles. This fact strongly implies that we should obtain in-situ information of noise levels to estimate reasonable sonar performance. As one of non-stationary noise sources, an eel may give serious problems to sonar operation on or under the sea bottoms. Observed eel noises in a pier of water depth 14m appear to have duration time of about 0.4 seconds and frequency ranges of 0.2-2.8kHz. The 'song'of an eel increases ambient noise levels to average 2.16dB in the frequencies concerned, being large enough to degrade detection performance of the sonars on or below sediments. An experiment using hydrophones in water and sediment gives that sensitivity drops of 3-4dB are expected for the hydrophones laid in sediment at frequencies of 0.5-1.5kHz. The SNR difference between in water and in sediment, however, shows large fluctuations rather than stable patterns with the source-receiver ranges.

OECD 급성경구투여독성시험 지침의 국내 확립 및 검증

조영래 ( Young Rae Cho ),염영나 ( Young Na Yum ),한의식 ( Eui Sik Han ),곽승준 ( Seung Jun Kwack ),김형섭 ( Hyung Sub Kim ),강미선 ( Mi Sun Kang ),이진영 ( Jin Young Lee ),오재호 ( Jae Ho Oh ),임채형 ( Chae Hyung Lim ),김대성 ( Da 한국동물실험대체법학회 2008 동물실험대체법학회지 Vol.2 No.2

As the study about the non-animal tests came to be internationally active and the interest in the animal welfare gradually became increased, OECD TG (Test Guideline) 401 that has been used since 1987 was abolished in 2002. Because TG401 is acute oral toxicity method depending on survival and death of many animals, it was heavily criticized. Therefore, the three alternative methods were developed. OECD TG420 and TG423 determine the class of chemicals according to GHS (Globally Harmonized Classification System for Chemical Substances and Mixtures) classification and OECD TG425 suggests the predicted LD50 of chemicals using AOT425 program. In this study, 10 chemicals were selected. The internationally admitted TG420, TG423 and TG425 were introduced and established through the method that these chemicals were orally administrated to SD female rats and then, the results were observed. Each chemical belonged to already known GHS class in the study using TG420 and TG423 and predicted LD50 was same or higher in the study using TG425 compared to already known LD50 value. In conclusion, the result of our study confirmed the decrease in the animal number and validated. The international harmonization of the non-animal tests will be pursued through this validation study.

Identification of a Marker Protein for Cardiac Ischemia and Reperfusion Injury by Two-Dimensional Gel Electrophoresis and Matrix-Assisted Laser Desorption Ionization Mass Spectrometry

Lee, Young-Suk,Kim, Na-Ri,Kim, Hyun-Ju,Joo, Hyun,Kim, Young-Nam,Jeong, Dae-Hoon,Cuong, Dang Van,Kim, Eui-Yong,Hur, Dae-Young,Park, Young-Shik,Hong, Yong-Geun,Lee, Sang-Kyung,Chung, Joon-Yong,Seog, Dae The Korean Society of Pharmacology 2004 The Korean Journal of Physiology & Pharmacology Vol.8 No.4

The purpose of the present study was to evaluate the expression of cardiac marker protein in rabbit cardiac tissue that was exposed to ischemic preconditioning (IPC), or ischemiareperfusion injury (IR) using two-dimensional gel electrophoresis (2DE) and matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS). We compared 2DE gels of control (uninjured) cardiac tissue with those of IPC and IR cardiac tissue. Expression of one protein was detected in IR heart tissue, however the protein was not detected in the samples of control and IPC tissue. To further characterize the detected protein molecule, the protein in the 2D gel was isolated and subjected to trypsin digestion, followed by MALDI-MS. The protein was identified as myoglobin, which was confirmed also by Western blot analysis. These results are consistent with previous studies of cardiac markers in ischemic hearts, indicating myoglobin as a suitable marker of myocardial injury. In addition, the present use of multiple techniques indicates that proteomic analysis is an appropriate means to identify cardiac markers in studies of IPC and IR.

Clinical significance of single-port laparoscopic splenectomy

Eui Soo Han,Young Kyoung You,Dong Goo Kim,Jun Suh Lee,Eun Young Kim,Soo Ho Lee,Tae Ho Hong,Gun Hyung Na 대한외과학회 2015 Annals of Surgical Treatment and Research(ASRT) Vol.89 No.2

Purpose: Single-port laparoscopic splenectomy has been performed sporadically. The aim of this study is to assess our experience with single-port laparoscopic splenectomy compared to conventional multiport laparoscopic surgery for the usual treatment modality for various kinds of splenic disease. Methods: Between October 2008 to February 2014, 29 patients underwent single-port laparoscopic splenectomy and 32 patients received multiport laparoscopic splenectomy. We retrospectively analyzed the clinical outcomes of single-port group and multiport group. Results: The body mass index and disease profiles of the both groups were similar. The operative times of single-port and multiport group were 113.6 ± 39.9 and 95.9 ± 38.9 minutes, respectively (P = 0.946). The operative blood loss of the two groups were 295.8 ± 301.3 and 322.5 ± 254.5 mL (P = 0.582). Postoperative retrieved splenic weight of the single-port and multiport groups were 283.9 ± 300.7 and 362.3 ± 471.8 g, respectively (P = 0.261). One single-port partial splenectomy and 6 multiport partial splenectomies were performed in this study. There was one intraoperative gastric wall injury. It occurred in single-port group, which was successfully managed during the operation. Each case was converted to laparotomy in both groups due to bleeding. There was one mortality case in the multiport laparoscopic splenectomy group, which was not related to the splenectomy. Mean hospital stay of the single-port and multiport group was 5.8 ± 2.5 and 7.3 ± 5.2 days respectively (P = 0.140). Conclusion: Single-port laparoscopic splenectomy seems to be a feasible approach for various kinds of splenic disease compared to multiport laparoscopic surgery.

Development of an Equine Antitoxin by Immunizing the Halla Horse with the Receptor-Binding Domain of Botulinum Neurotoxin Type A1

( Na Young Kim ),( Kyung-eui Park ),( Yong Jin Lee ),( Yeong Mun Kim ),( Sung Hyun Hong ),( Won Rak Son ),( Sungyoul Hong ),( Saehyung Lee ),( Hye Bin Ahn ),( Jaehyuk Yang ),( Jong-pil Seo ),( Yoon-Ky 한국미생물생명공학회 2019 Journal of microbiology and biotechnology Vol.29 No.7

Botulinum neurotoxins (BoNTs), produced by Clostridium botulinum, are the most toxic substances known. However, the number of currently approved medical countermeasures for these toxins is very limited. Therefore, studies on therapeutic antitoxins are essential to prepare for toxin-related emergencies. Currently, more than 10,000 Halla horses, a crossbreed between the native Jeju and Thoroughbred horses, are being raised in Jeju Island of Korea. They can be used for equine antitoxin experiments and production of hyperimmune serum against BoNT/A1. Instead of the inactivated BoNT/A1 toxoid, Halla horse was immunized with the receptor-binding domain present in the C-terminus of heavy chain of BoNT/A1 (BoNT/A1-HCR) expressed in Escherichia coli. The anti-BoNT/A1-HCR antibody titer increased rapidly by week 4, and this level was maintained for several weeks after boosting immunization. Notably, 20 μl of the week-24 BoNT/A1-HCR(-immunized) equine serum showed an in vitro neutralizing activity of over 8 international units (IU) of a reference equine antitoxin. Furthermore, 20 μl of equine serum and 100 μg of purified equine F(ab’)₂ showed 100% neutralization of 10,000 LD₅₀ in vivo. The results of this study shall contribute towards optimizing antitoxin production for BoNT/A1, which is essential for emergency preparedness and response.