3D flexible Si based-composite (Si@Si₃N₄)/CNF electrode with enhanced cyclability and high rate capability for lithium-ion batteries

Kim, Si-Jin,Kim, Min-Cheol,Han, Sang-Beom,Lee, Gyu-Ho,Choe, Hui-Seon,Kwak, Da-Hee,Choi, Sun-Yong,Son, Byung-Goo,Shin, Myoung-Sun,Park, Kyung-Won Elsevier 2016 Nano energy Vol.27 No.-

<P><B>Abstract</B></P> <P>Despite extremely high capacity of Si-based anodes in lithium-ion batteries (LIB), Si-based materials have shown a structural collapse caused by a volumetric expansion/contraction during the cycling process. The conventional electrode structure, which consists of active materials, a current collector, a conducting agent, and a binder, actually showed a low loading of active material due to the other heavy components. In this study, we prepared a 3D flexible Si-composite electrode consisting of core (Si)-shell (Si<SUB>3</SUB>N<SUB>4</SUB>) NPs (Si@Si<SUB>3</SUB>N<SUB>4</SUB>) and carbon nanofibers (denoted as Si-composite/CNF). The Si-composite/CNF was directly utilized as an anode in the absence of the other components was electrochemically evaluated using a coin-type cell. The Si-composite/CNF showed a high capacity of 665mAhg<SUP>−1</SUP> at a fairly high current density of 10Ag<SUP>−1</SUP> and an extremely low capacity loss for 2000 cycles.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We prepared Si-composite/CNF exhibits a 3D flexible Si-composite electrode. </LI> <LI> The electrode consists of core (Si)-shell (Si<SUB>3</SUB>N<SUB>4</SUB>) NPs (Si@Si<SUB>3</SUB>N<SUB>4</SUB>) and carbon nanofibers. </LI> <LI> The Si-composite/CNF was directly utilized as an anode. </LI> <LI> Si-composite /CNF exhibited high specific capacity and improved high rate cycling performance. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

가압가열 및 Microwave 처리가 생면의 품질에 미치는 영향

박시우,김꽃봉우리,김민지,강보경,박원민,김보람,박홍민,최정수,최호덕,안동현,Bark, Si-Woo,Kim, Koth-Bong-Woo-Ri,Kim, Min-Ji,Kang, Bo-Kyeong,Pak, Won-Min,Kim, Bo-Ram,Park, Hong-Min,Choi, Jung-Su,Choi, Ho-Duk,Ahn, Dong-Hyun 한국식품영양학회 2013 韓國食品營養學會誌 Vol.26 No.4

중력분을 이용하여 제면한 후 가압가열, microwave 및 가압가열과 microwave 병행 처리한 후, 생면 및 삶은 면의 품질에 미치는 영향에 대하여 알아보았다. 생면의 pH는 microwave 1 min 처리구에서 무처리구와 유의적인 차이를 보이지 않았으며, 수분 함량은 autoclave 50 min 처리구에서 무처리구와 유의적인 차이를 보이지 않았고, 그 외의 처리구에서는 모두 수분 함량이 감소함을 확인하였다. 면의 색도 측정 결과는 명도는 무처리구에 비해 모든 처리구에서 감소하였으며, 적색도는 microwave 1 min 처리구는 감소한 반면, 나머지 처리구는 증가하였다. 황색도는 autoclave 50 min 처리구와 autoclave 50 min/microwave 1 min 병행 처리구에서 증가한 반면, 나머지 물리적 처리구에서는 감소하였다. 삶은 면의 색도에서는 명도, 적색도, 황색도 모두에서 무처리구에 비하여 물리적 처리구에서 증가한 값을 나타내었다. 물성 측정 결과는 경도, 부착성, 응집성, 검성, 복원성에서 무처리구와 비교시 microwave 1 min 처리구는 유의적으로 감소하였으며, 그 외 처리구에서는 유의적으로 증가한 값을 나타내었다. 탄력성과 전단력은 모든 처리구에서 유의적으로 증가하였으며, 인장력은 가압가열 30 min 처리구와 무처리구가 유의적인 차이를 보이지 않았으나, 나머지 물리적 처리구에서는 유의적으로 증가하였다. 관능 평가 결과는 생면의 경우 색 항목에서 물리적 처리구들이 유의적으로 낮은 점수를 받았다. 맛, 질감, 향 항목에서는 무처리구와 물리적 처리구간 유의적 차이를 보이지 않았다. 전체적인 기호도에서는 microwave 1 min 처리구가 가장 높은 점수를 얻었으며, 가압가열(50 min)과 microwave(1 min) 병행 처리구는 무처리구와 비슷한 점수를 얻었다. 따라서 제면 후 가압가열 및 microwave 처리가 생면 및 삶은 면에 있어서 색과 질감 항목을 보완, 개선시킨다면 알러겐성이 저감화된 면을 제품화하는데 적합할 것으로 사료되어진다. This study was conducted to determine the effects of physical treatments for quality of wet noodles. Noodles were being tried with a microwave (for 1 min), an autoclave (for 30 or 50 min), and both autoclave and microwave (for 30/1 min or 50/1 min). The results showed that the pH levels were slightly decreased after treatments of autoclave and autoclave/microwave. The moisture contents were considerably decreased as compared to the control except autoclave (50 min). After all treatments, the lightness was decreased in all samples, but, redness was increased (except microwave) and the yellowness was increased after autoclave (50 min) and autoclave/microwave (50/1 min). Texture was increased as compared to the control except microwave. In the sensory evaluation, the noodles treated with microwave, autoclave (50 min), and autoclave/ microwave (50/1 min) showed a high score in overall preference. From these results, both the autoclave and microwave methods can be applied to the wet noodles without diminishing its quality to a great extent.

Comparison of time and cost between conventional surgical planning and virtual surgical planning in orthognathic surgery in Korea

Park, Si-Yeon,Hwang, Dae-Seok,Song, Jae-Min,Kim, Uk-Kyu Korean Association of Maxillofacial Plastic and Re 2019 Maxillofacial Plastic Reconstructive Surgery Vol.41 No.-

Background: The purpose of this study was to measure the time of the conventional surgical planning (CSP) and virtual surgical planning (VSP) in orthognathic surgery and to compare them in terms of cost. Material and method: This is a retrospective study of the patients who underwent orthognathic surgery at the Pusan National University Dental Hospital from December 2017 to August 2018. All the patients were analyzed through both CSP and VSP, and all the surgical stents were fabricated through manual and three-dimensional (3D) printing. The predictor variables were the planning method (CSP vs. VSP) and the surgery type (group I: Le Fort I osteotomy + bilateral sagittal split osteotomy [LFI+BSSO] or group II: only bilateral sagittal split osteotomy [BSSO]), and the outcomes were the time and cost. The results were analyzed using the paired t test. Results: Thirty patients (12 females, 18 males) met the inclusion criteria, and 17 patients were excluded from the study due to missing or incomplete data. There were 20 group I patients (LFI+BSSO regardless of genioplasty) and 10 group II patients (BSSO regardless of genioplasty). The average time of CSP for group I was 385 ± 7.8 min, and that for group II was 195 ± 8.33 min. The time reduction rate of VSP compared with CSP was 62.8% in group I and 41.5% in group II. On the other hand, there was no statistically significant cost reduction. Conclusions: The time investment in VSP in this study was significantly smaller than that in CSP, and the difference was greater in group I than in group II.

An automated quality assurance system with deep learning for small cube-ball phantom localization in noisy megavoltage images

Park Min-Jae,Lee Gyemin,Kwak Jungwon,Jeong Chiyoung,Goh YoungMoon,Kim Sung-woo,Cho Byungchul,Song Si Yeol,Kim Jong Hoon,Jung Jinhong,Shin Young Seob,Oh Jungsu 한국물리학회 2024 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.84 No.9

To enhance effi ciency and minimize errors, we automated the quality assurance (QA) process in radiation oncology, specifi - cally laser localization. Additionally, we explored the use of a convolutional neural network (CNN) to enhance the detection of small cube-ball phantoms in noisy images. Laser localizations were measured manually on the acquired images. To automate the QA workfl ow, we developed a Linux server equipped with database and web servers. Digital Imaging and Communications in Medicine (DICOM) fi les were retrieved 40 times for 10 linear accelerators (LINACs). The center of the cube-ball phantoms was estimated through Gaussian fi tting. We applied CNN using 6,968 stored results to improve the estimation performance in noisy megavoltage (MV) images. Subsequently, both analysis time and accuracy were compared. Our hospital has been employing the automated QA system since 2018, notably reducing the time for laser localization from 30 min to just 1 min. The average and standard deviation (SD) of inter-observer variability in the X- and Y-axes were 0.06 ± 0.01 mm and 0.05 ± 0.01 mm, respectively. Absolute diff erences between manual assessment and Gaussian fi tting presented average and SD values of 0.40 ± 0.51 mm and 0.23 ± 0.24 mm, respectively. In contrast, absolute diff erences between manual assessment and CNN presented average and SD values of 0.12 ± 0.10 mm and 0.11 ± 0.09 mm, respectively. Overall, the automated QA system signifi cantly hastened procedures in our large hospital and improved the estimation of the cube-ball phantom’s position in noisy images through deep learning.

Development of electrochemical biosensor for detection of pathogenic microorganism in Asian dust events

Yoo, Min-Sang,Shin, Minguk,Kim, Younghun,Jang, Min,Choi, Yoon-E,Park, Si Jae,Choi, Jonghoon,Lee, Jinyoung,Park, Chulhwan Elsevier 2017 CHEMOSPHERE - Vol.175 No.-

<P><B>Abstract</B></P> <P>We developed a single-walled carbon nanotubes (SWCNTs)-based electrochemical biosensor for the detection of <I>Bacillus subtilis,</I> one of the microorganisms observed in Asian dust events, which causes respiratory diseases such as asthma and pneumonia. SWCNTs plays the role of a transducer in biological antigen/antibody reaction for the electrical signal while 1-pyrenebutanoic acid succinimidyl ester (1-PBSE) and ant-<I>B. subtilis</I> were performed as a chemical linker and an acceptor, respectively, for the adhesion of target microorganism in the developed biosensor. The detection range (10<SUP>2</SUP>–10<SUP>10</SUP> CFU/mL) and the detection limit (10<SUP>2</SUP> CFU/mL) of the developed biosensor were identified while the response time was 10 min. The amount of target <I>B. subtilis</I> was the highest in the specificity test of the developed biosensor, compared with the other tested microorganisms (<I>Staphylococcus aureus</I>, <I>Flavobacterium psychrolimnae</I>, and <I>Aquabacterium commune</I>). In addition, target <I>B. subtilis</I> detected by the developed biosensor was observed by scanning electron microscope (SEM) analysis.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A SWCNTs-based biosensor was developed for the detection of <I>Bacillus subtilis.</I> </LI> <LI> The biosensor was composed of SWCNTs, 1-PBSE, and anti-<I>B. subtilis</I> antibody. </LI> <LI> The performance of the biosensor was assessed using a sensor sensitivity and specificity tests. </LI> <LI> The detection limit and detection range were 10<SUP>2</SUP> and 10<SUP>2</SUP>–10<SUP>10</SUP> CFU/mL, respectively. </LI> <LI> The detection time of the biosensor was identified as 10 min. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

석면함유 슬레이트 지붕 물받이 퇴적물 중 석면 섬유 함유율

임지현,한솔민,김현석,신유민,박시은,허정윤,김민영,장봉기 순천향대학교 기초과학연구소 2022 순천향자연과학연구 논문집 Vol.28 No.1,2

This study attempted to determine the degree of asbestos release from the aging slate roof by comparing the asbestos content in the slate roof rain gutter with a colored steel plate (tin plate) over the slate roof. Four slate roof houses located in Haengmok-ri, Asan-si, Chungcheongnam-do, and one house constructed with a colored steel plate on the slate roof were selected to collect the sediment of the roof rain gutter. The asbestos fiber content was calculated by a point counting method using a polarization microscope after pretreatment with conversion treatment and hydrochloric acid treatment. The average asbestos content of the four slate roof rain gutter were 1.89%. However, asbestos was not detected in the Slate covering roof rain gutter, which were constructed on the slate roof. Asbestos fiber content was the highest at 2.89% in the slate roof rain gutter installed in 1976, followed by 2.44% in 1953. From the above results, it is necessary to minimize secondary damage as asbestos fibers released from slate roof houses to the surrounding atmosphere or leaked from slate roofs as rainwater may cause soil pollution and seriously affect residents' health. Although covering with colored steel plates (tin plates) has been shown to prevent the leakage of asbestos fibers to some extent, it is believed that a policy alternative to remove the slate roof as soon as possible is needed to solve the fundamental problem.

기능성 위장관 장애에서 혈청 IL-1β, IL-2,IL-6의 변화 : 우울증 및 스트레스와의 상관성

박시성,이상신,박무인,구자영,박제민,김명정 한국정신신체의학회 2002 정신신체의학 Vol.10 No.2

Mitomycin-C 적용시간에 따른 누낭비강연결술의 수술결과

박근성,임진호,민병무,최시환,김창식,김용백 충남대학교 의학연구소 2001 충남의대잡지 Vol.28 No.2

To determine the usefulness of application of Mitomycin-C (MMC) and effectiveness of different concentration of MMC in external DCR. A total of 100 eyes of 87 patients diagnosed with primary acquired nasolacrimal duct obstruction were assigned randomly to either a MMC group or control group. The surgical procedures in both groups were same. In MMC group, a piece of neurosurgical cottonoid soaked with 0.4 mg/ml MMC was applied to the osteotomy site and then was removed after 5 and 10 minutes differently. Nasoendoscopic examination was performed at 1 month, 3 months, and 6 months after surgery for all patients. The causes of epiphora as trauma (20 cases), failed DCR (1 case), sinus surgery (2 cases), unknown (77 cases). The overall anatomical success rate of the procedure was 88% and functional success rate was 79%. Obstruction site was related to anatomical surgical results. Anatomical surgical outcome at lower lacrimal sac level group of patients showed a statistically significant success rate, but functional surgical outcome showed no significant difference between the two groups. The anatomical success rate was 87.7% and the functional success rate was 84.2% in MMC group. The anatomical success rate was 88.3% and the functional success rate was 74.4% in control group. Application of MMC and it's application time were not related to surgical results.

음전하를 띤 Microsphere 에 의한 정전기적 반발력이 정밀여과에서 투과 플럭스에 미치는 영향 고찰

박정민,최성욱,방시원,함승주,김중현,김우식 한국화학공학회 2001 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.39 No.6

본 연구에서는 일정 압력하에서 음전하를 띤 microspheres의 정전기적 반발력에 따른 투과 플럭스의 변화에 관하여 고찰하였다. Microsphere의 정전기적 반발력에 관한 영향을 관찰하기 위해 표면전하 밀도(N_c: 0.45, 5.94, 10.25)가 각각 다른 poly(Styrene/Methacrylic acid) microspheres를 제조하였다. 교반속도는 300, 400, 600 rpm, 이온강도는 0.1, 0.01, 0.001로 변화시켜 실험하였다. 투과 플럭스는 표면전하밀도, 교반속도, 이온강도에 큰 영향을 받음을 알 수 있었으며, 투과 플럭스는 표면전하밀도가 클수록, 교반속도가 증가할수록, 이온강도가 작을수록 증가함을 알 수 있었다. 교반속도가 크면 막표면의 농도분극층의 두께가 얇아지기 때문에 투과 플럭스는 증가한다. 이온강도가 작을수록, 표면전하밀도(surface charge density)가 클수록 투과 플럭스가 커지는 원인은 microspheres의 정전기적 이중 층의 두께가 두꺼워짐에 따라 입자 사이의 거리가 멀어져 공극률(porosity)이 커지기 때문이다. 정상상태 플럭스 자료로부터 비 저항 정의식을 이용하여 케이크층의 공극률을 구할 수 있었다. 전하를 나타내지 않는 polystyrene microspheres의 입자크기가 480㎚일 때 농도분극 층의 이론적인 공극률은 0.211이었고, microspheres의 표면이 methacrylic acid로 완전히 개질된 것은 비 저항정의식에 의해 3.04로 계산되었다. 또한 microspheres들간의 정전기적 상호작용력이 작아지면 농도분극층의 공극률도 줄어드는 것을 알 수 있었다. The effect of the surface charge density(N_c: 0.45, 5.94, 9.14 and 10.25) and the stirrer speed(300, 400 and 600 rpm) on the variation of permeate flux was investigated in a stirred cell filled with negatively charged microspheres under constant pressure. It was found that the permeate flux depended on the surface charge density, the ionic strength and the stirrer speed. High permeate flux was obtained in the condition of high surface charge density, low ionic strength and high stirrer speed due to the force of electrostatic interaction between microspheres. The porosity of a cake layer was calculated from the steady-state flux data. It was found that the reduction of porosity was due to a decrease in repulsive interaction between microspheres.

재발성 다발성 연골염

박용범,이시훈,정상윤,이수곤,홍순원,김정민,이창률 대한내과학회 2001 대한내과학회지 Vol.61 No.3