스펙트럼 영역 빛간섭단층촬영을 이용한 연령과 성별에 따른 황반형태 연구

채민병,김재석,Min Byung Chae,MD,Jae Suk Kim,MD,PhD 대한안과학회 2014 대한안과학회지 Vol.55 No.10

Purpose: To compare foveal shapes in Koreans according to age and gender using spectral domain optical coherence tomography (SD-OCT). Methods: This study included 230 eyes of 115 healthy adults. The subjects were divided into three groups: group 1 (20-39 years of age), group 2 (40-59 years of age) and group 3 (60-79 years of age). Using spectralis OCT, we measured central foveal thickness (CFT), regional maximal retinal thickness (MRT), pit diameter and pit depth and compared the differences between the groups. Results: The MRT of the superior, inferior and nasal sides in group 1 was higher than in groups 2 and 3 (<EM>p</EM> < 0.05). No significant difference was observed in the MRT of the temporal side. Regarding differences based on age, no significant differences in CFT, pit diameter and pit depth were observed. Regarding differences in gender, the temporal regional MRT of males in group 3 was significantly lower than in group 1 and the pit depth of males in group 1 was significantly higher than in groups 2 and 3. Therefore, differences were observed according to gender.Conclusions: In the present study, differences in foveal shape were found according to age and gender which should be considered when foveal diseases are evaluated.J Korean Ophthalmol Soc 2014;55(10):1504-1510

외상 후 발생한 양안 중심장액맥락망막병증 1예

채민병,송미령,김태진,하효신,박정현,Min Byung Chae,Mi Ryoung Song,Tai Jin Kim,Hyo Shin Ha,Jung Hyun Park 대한안과학회 2014 대한안과학회지 Vol.55 No.8

Purpose: To report a case of bilateral central serous chorioretinopathy (CSC) after blunt trauma with rapid remission. Case summary: A 44-year-old man visited our clinic after blunt trauma around the right eye. At the first examination, no ocular problem was detected except a periorbital contusion. After one week, the patient complained of visual disturbance in his right eye. Fundus examination showed subretinal fluid in his right eye, and fluorescein angiography (FAG) showed typical smokestack pattern leakage, which lead to a diagnosis of CSC. Three days later, the patient complained of visual disturbance in his left eye, which was then also diagnosed as CSC. After 2 more weeks, the subretinal fluid in the right and left eyes had decreased. After 3 weeks, the subretinal fluid was almost completely absorbed in both eyes. Conclusions: Central serous chorioretinopathy can develop after blunt trauma, especially with a rapid clinical course. Thus, periodic ophthalmologic examination is needed after the first examination for blunt trauma of the eye. J Korean Ophthalmol Soc 2014;55(8):1248-1252

림프절병증 환자에서 Bartonella henselae와 Bartonella quintana에 대한 항체 양성률

채민병,이지영,곽이경,박성학,임희정,박상우,정문현,김미경,강재승 대한감염학회 2002 감염 Vol.34 No.5

초음파화학법으로 합성한 광촉매 산화아연 나노입자와 PCM 마이크로캡슐을 복합한 잠수복용 고무 시트의 보온성 및 항균성

채하늘,이승한,민병길 한국섬유공학회 2023 한국섬유공학회지 Vol.60 No.3

Photocatalytic ZnO nanoparticles were synthesized through sonochemical synthesisprocess for depositing them onto PCM microcapsules for the purpose to providewarming ability and antibacterial activity to rubber sheets for diving suit. Spherical ZnOnanoparticles having average diameter of 50 nm could be synthesized in deionized waterunder ultrasonic irradiation for 30 min at pH 11.5. However, needle-like ZnO nanoparticleswere obtained in ammonium hydroxide instead of deionized water as medium. It wasfound that spherical shape is more favorable for the sonochemical coating thereof ontoPCM microcapsules. The formation of ZnO nanopartcles through Zn(OH)2 microparticleswere confirmed using UV-Vis spectroscopy and X-ray diffractometry. Composite rubbersheets containing 0-25 wt% of PCM microcapsules with or without ZnO nanoparicles wereprepared by solution casting. The composite rubber sheets exhibited much better warmingability compared than neat rubber sheet in cold water due to exothermic heat by PCMmicrocapsules. Moreover, The composite rubber sheets with ZnO nanoparicles showedexcellent antibacterial activity against bacteria of S. aureus by showing 99.9 % reduction ofbacteria.

저전력 멀티미디어 응용을 위한 10b 100 MSample/s $1.4\;mm^2$ 56 mW 0.18 um CMOS A/D 변환기

민병한,박희원,채희성,사두환,이승훈,Min Byoung-Han,Park Hee-Won,Chae Hee-Sung,Sa Doo-Hwan,Lee Seung-Hoon 대한전자공학회 2005 電子工學會論文誌-SD (Semiconductor and devices) Vol.42 No.12

This work proposes a 10b 100 MS/s $1.4\;mm^2$ CMOS ADC for low-power multimedia applications. The proposed two-step pipeline ADC minimizes chip area and power dissipation at the target resolution and sampling rate. The wide-band SHA employs a gate-bootstrapping circuit to handle both single-ended and differential inputs with 1.2 Vp-p at 10b accuracy while the second-stage flash ADC employs open-loop offset sampling techniques to achieve 6b resolution. A 3-D fully symmetrical layout reduces the capacitor and device mismatch of the first-stage MDAC. The low-noise references are integrated on chip with optional off-chip voltage references. The prototype 10b ADC implemented in a 0.18 um CMOS shows the maximum measured DNL and INL of 0.59 LSB and 0.77 LSB, respectively. The ADC demonstrates the SNDR of 54 dB, the SFDR of 62 dB, and the power dissipation of 56 mW at 100 MS/s. 본 논문에서는 저 전력 멀티미디어 응용을 위한 10b 100 MS/s $1.4\;mm^2$ CMOS A/D 변환기(ADC)를 제안한다. 제안하는 ADC는 해상도 및 속도 사양을 만족시키면서, 면적 및 전력 소모를 최소화하기 위해 기존의 다단 구조가 아닌 2단 파이프라인 구조를 사용하였다. 그리고 10 비트 해상도에서 1.2 Vp-p의 단일 및 차동 입력 신호 처리 대역폭을 넓히기 위해 입력 샘플-앤-홀드 증폭기에는 게이트-부트스트래핑 회로를 적용하며, 6 비트 해상도를 필요로 하는 두 번째 단의 flash ADC에는 오픈-루프 오프셋 샘플링 기법을 적용하였다. 또한 커패시터 등 소자 부정합에 의해 해상도에 크게 영향을 줄 수 있는 MDAC의 커패시터에는 3차원 완전 대칭 구조를 갖는 레이아웃 기법을 제안하였다. 기준 전류/전압 발생기는 온-칩으로 집적하여 잡음 에너지를 줄였으며, 필요시 선택적으로 다른 크기의 기준 전압을 외부에서 인가하도록 설계하였다. 제안하는 10b 시제품 ADC는 0.18 um CMOS 공정으로 제작되었고, 측정된 DNL 및 INL은 각각 0.59 LSB, 0.77 LSB 수준을 보여준다. 또한 100 MS/s의 샘플링 속도에서 SNDR 및 SFDR이 각각 54 dB, 62 dB 수준을 보였으며, 전력 소모는 56 mW이다.

상전이물질 마이크로캡슐의 표면에 초음파화학 코팅법으로 항균성 구리 나노입자의 도입

이지헌,채하늘,민병길 한국섬유공학회 2022 한국섬유공학회지 Vol.59 No.1

In this study, phase change material (PCM) microcapsules were prepared, andcopper nanoparticles were coated on the microcapsule surface through the sonochemicalcoating process for temperature regulation and antibacterial activities. n-octadecane andmelamine–formaldehyde resin were used as the PCM core and wall materials of microcapsules,respectively. It was observed that applying high-speed stirring above 7,000 rpm wascritical to form n-octadecane droplets in O/W emulsion with 3.5±0.5 μm in diameter usinga homogenizer. Spherical PCM microcapsules with 6.0±2 μm in diameter could beobtained at lower than pH 6. Copper nanoparticles could be successfully embedded onthe surface of PCM microcapsules through the sonochemical coating process. The PCMmicrocapsules coated with copper nanoparticles exhibited excellent antibacterial activitiesagainst S. aureus and K. pneumonia.

In situ Shape-Stabilization of n-Octadecane PCM in Alginate Matrix through Formation of Emulsion and Solidification by Ionic Crosslinking

이승한,채하늘,김남윤,민병길 한국섬유공학회 2022 Fibers and polymers Vol.23 No.9

A novel in situ shape-stabilization process of paraffinic phase change material (PCM) in alginate matrix wasinvestigated for the purpose of temperature regulating application. n-Octadecane was selected as a paraffinic PCM because ofits adequate thermal transition temperature for applying to human body. As the size control of n-octadecane in polymermatrix less than 10 μm is a core factor for textile application, oil-in-water (O/W) emulsion of n-octadecane in water wereadopted for the size control in shape-stabilization of PCM (SSPCM) in polymer matrix. The micelle size of the PCMemulsion could be controlled in the range of 3-8 μm through O/W emulsion process with high-speed stirring at 3,000-7,000 rpm and small amount of surfactant. The size of micelles in the emulsion decreased with increasing of homogenizingspeed and the amount of surfactant. It was also confirmed that the PCM micelle size was maintained in alginate-PCM hybridsolution that was prepared by mixing the O/W emulsion and aqueous sodium alginate solution. The SSPCM films containing10-30 wt% of n-octadecane in alginate could be successfully prepared by casting the hybrid solution followed by coagulatingthe cast film in aq. CaCl2 resulting solidification and insolubilization of alginate through intermolecular ionic crosslinking byCa2+. It was interesting that the shape of n-octadecane in alginate matrix was not spherical but disk shape parallel to the filmsurface. It was presumed that the discus-type shape-stabilized form of n-octadecane in alginate matrix was originated byvertical compressive force applied during rapid coagulation of the hybrid solution having very low concentration of sodiumalginate (4 wt%). The shape of paraffinic PCM stabilized in polymer matrix through O/W emulsion is expected to becontrolled when the other polymeric system with thick concentration.

알긴산/PVA 블렌드에 동시형태고정화된 상전이물질 옥타데칸의 형상변화 및 계면 형태가 용융잠열에 미치는 영향

이승한,채하늘,신창민,홍성민,민병길 한국고분자학회 2023 폴리머 Vol.47 No.1

수용성 고분자인 알긴산/poly(vinyl alcohol)(PVA) 블렌드 수용액에 상전이물질인 옥타데칸이 동시형태고정화된 복합필름을 제조하여 옥타데칸의 상분리 형상과 계면 특성이 잠열효율에 미치는 영향을 분석하였다. 고분자의농도를 4-18 wt%까지 조절하면서 옥타데칸을 동시형태고정화 시켰을 때, 낮은 농도에서는 디스크 형상으로 형태고정화 되었으나 고분자 농도가 증가함에 따라 종횡비가 낮아지면서 구형에 가까운 형상으로 형태고정됨을 알 수 있었다. 종횡비가 낮아질수록 계면의 비표면적이 작아지고 이에 따라 결정화에 방해를 받는 계면에 존재하는 옥타데칸의 비율이 낮아짐으로써 잠열효율이 증가하는 결과를 나타내었다. 또한 알긴산/PVA를 가교반응으로 개질하였을경우 동일조건에서 옥타데칸의 잠열효율이 낮아지는 것으로 나타났는데, 이는 가교에 따라 계면에 미세 요철이 발달되어 결과적으로 옥타데칸의 결정화가 방해된 것에 기인한 것으로 판단된다.

초음파화학 공정에 의한 파라핀계 상전이물질의 에멀전 형성과 이로 부터 멜라민-포름알데히드 수지를 벽 재료로 사용한 마이크로캡슐의 제조

한창훈,채하늘,민병길,Han, Chang-Hoon,Chae, Haneul,Min, Byung Gil 한국섬유공학회 2021 한국섬유공학회지 Vol.58 No.4

An O/W emulsion of paraffinic phase change material (PCM) was prepared through a sonochemical process for microencapsulation using melamine-formaldehyde resin as the wall material. It was found that the octadecane micelles selected as PCM were successfully formed in water with a diameter of 1-3 ㎛ through ultrasonication for 5 min. Anionic surfactants were found to be more effective than non-ionic surfactants in the formation of emulsions consisting of PCM micelles through a sonochemical process. Spherical PCM microcapsules were obtained from the PCM emulsion and melamine-formaldehyde prepolymer, which was used as the wall material. The diameter of the PCM microcapsules increased with increasing microencapsulation time and the prepolymer to PCM weight ratio.

한국인 원발폐쇄각녹내장 환자의 중심각막두께

장인범,채민병,박정현,김태진,김재석,In Boem Chang,Min Byung Chae,Jung Hyun Park,Tai Jin Kim,Jae Suk Kim 대한안과학회 2014 대한안과학회지 Vol.55 No.3

Purpose: To compare the central corneal thickness (CCT) in eyes of Korean subjects with primary angle-closure glaucoma (PACG) to other patients with glaucoma and control subjects. Methods: Medical records of patients who underwent examination for glaucoma and pre-operative examination for cataract surgery between March 2009 and August 2012 in our clinic were reviewed. CCT was compared in normal control eyes, primary open angle glaucoma (POAG) eyes and normal tension glaucoma (NTG) eyes. Results: The mean CCT of POAG eyes was significantly larger than that of normal control eyes, NTG eyes and PACG eyes (p = 0.027, 0.009 and 0.008, respectively). There was no significant difference in mean CCT between normal control eyes, NTG eyes or PACG eyes. Conclusions: PACG eyes had a CCT similar to that of NTG or normal eyes in Korean subjects. J Korean Ophthalmol Soc 2014;55(3):402-407