칼슘이 용출된 모르타르 시험체의 염소이온 침투 저항성

최윤석,장연주,박지영 한국구조물진단유지관리공학회 2019 한국구조물진단유지관리공학회 학술발표대회 논문집 Vol.2019 No.04

In this study, the effect of calcium leaching on chloride ion penetration resistance of mortar specimens was evaluated. According to test results, the penetration depth of chloride ion was increased after the calcium leaching attack.

2P-546 : Introducing ordered mesoporous structure to Si/SiO_x nanocomposites

최윤석,이지혜,김지만 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

Among the competitive materials for next-generation LiB anodes, Si based materials have attracted substantial interest as a high energy density anode due to their high theoretical capacity. Nevertheless, practical use of Si-based anode materials is obstructed owing to their drastic volume changes during the lithium insertion and extraction which result in capacity fading. Introducing nanopores could be an adequate approach to relieve volumetric tension. Nanoporous structure not only provides buffer space for volume changes but facilitates efficient transportation of Li ions and electrons. On the other hand, SiO_x (x < 2), contains nano-sized Si particles dispersed in a matrix of SiO₂, has gradually adopted as compatible Si-based anode material. Based on the above-mentioned strategy, we synthesized ordered mesoporous Si/SiO_x for LiB anode materials and Si nanoparticle embedded ordered mesoporous Si/SiO_x nanocomposites.

포르만트를 이용한 한국어 단모음 분류 시스템의 개발에 관한 연구 ( A Study on The Development of The Korean Vowel Discrimination System Using Formant )

최윤석,김기석,황희웅 대한전자공학회 1987 대한전자공학회 학술대회 Vol.1987 No.7

한국인에서 Medpor를 이용한 비주지주 술식의 유용성

최윤석,윤석영,장태영 대한이비인후과학회 2007 대한이비인후과학회지 두경부외과학 Vol.50 No.9

Background and Objectives:Nasal tip plasty is a dificult procedure especially in Koreans who have a thick skin, abundant sub-cutaneous tisue and weak cartilage. Columela strut using autologus cartip supporting procedure, is frequently used in Koreans. Autologus graft material suply is often limited and harvesting entails aditional morbidity. So, the purpose of this study is to investigate the usefulnes of Medpor as columella strut material and its complication. Subjects and Method:We studied 38 patients who underwent nasal tip plasty. Case group (n= 19) underwent tip plasty using Medpor as columela strut material. However, the other group (n= 19)The result of surgery was evaluated on the basis of pre-operative, one and twelve months post-operative photographic analyses. All results were statistically analyzed. Results:Tip projection was 10.3% in the Medpor used group, 5.8% in the cartilage used group at one month after surgery. Tip projection were 8.7% and 4.4% in each group at twelve months after surgery. The degree of tip cephalic rotation was 10.1 degre for the Medpor used cases, and 5.3 degres for cartilage used cases at 1 month after surgery. f tip projection and tip rotation was measured 1.9% and 1.2 degrees in the Medpor used group and 2.4% and 2.1 degrees in the cartilage used group. There was only one case of complication;the extrusion of Medpor into the nasal cavity. Conclusion:Med-por can be a good substitute for columella strut material for Koreans who have weak and small amount of cartilages. (Korean J Otorhinolaryngol-Head Neck Surg 2007 ;50 :773-8)

HWSD와 정밀토양도를 이용한 유출해석시 토양 매개변수 특성 비교 평가

최윤석,정영훈,김주훈,김경탁,Choi, Yun Seok,Jung, Young Hun,Kim, Joo Hun,Kim, Kyung-Tak 한국농공학회 2016 한국농공학회논문집 Vol.58 No.4

Harmonized World Soil Database (HWSD) including the global soil information has been implemented to the runoff analysis in many watersheds of the world. However, its accuracy can be a critical issue in the modeling because of the limitation the low resolution reflecting the physical properties of soil in a watershed. Accordingly, this study attempted to assess the effect of HWSD in modeling by comparing parameters of the rainfall-runoff model using HWSD with the detailed soil map. For this, Grid based Rainfall-runoff Model (GRM) was employed in the Hyangseok watershed. The results showed that both of two soil maps in the rainfall-runoff model are able to well capture the observed runoff. However, compared with the detailed soil map, HWSD produced more uncertainty in the GRM parameters related to soil depth and hydraulic conductivity during the calibrations than the detailed soil map. Therefore, the uncertainty from the limited information on soil texture in HWSD should be considered for better calibration of a rainfall-runoff model.

Can the Initial Electrical Performance of Pacemaker Lead Predict the Lead Longevity?

최윤석,오용석,이동현,김지훈,신우승,박철수,윤호중,정욱성,이만영,승기배,노태호,김재형,최규보,홍순조 대한내과학회 2005 대한내과학회 추계학술대회 Vol.2005 No.1

전핵 미세 주입법으로 생산된 한국흑염소 수정란의 이식 조건이 수태율에 미치는 영향

최윤석,신현국,장성근,양홍석,이옥근,이두수,조종기,신상태 韓國受精卵移植學會 2007 한국동물생명공학회지 Vol.22 No.1

본 연구는 PI한 한국흑염소 수정란의 이식 결과를 통해 수란 흑염소의 수태율에 영향을 미칠 것으로 생각되는 여러 가지 요인을 분석함으로써, 높은 수태율을 얻을 수 있는 수란 흑염소의 최적 조건을 찾아낼 목적으로 수행하였다. 분석 결과, 수태율에 유의적인 영향을 주는 요인들은 발정형태, 수술 빈도, 이식 부위, 황체의 발육 단계, 수정란의 발육단계, 이식된 수정란의 수 등이었다. 자연 발정이 관찰되어 이식된 흑염소(59.1%, 13/22)들이 로 발정이 This study was investigated factors affecting the pregnancy rates after transfer of pronuclear microinjected embryos for the production of transgenic Korean black goats. Embryo transfer was carried out in 343 recipient Korean black goats from September 1999 to June 2000. Estrus was induced by the insertion of intravaginal progesterone devices for 2 weeks. A single injection of 400 IU equine chorionic gonadotropin was administered at 48h before removal to increase the proportion of does cycling and ovulation rate. Good quality embryos were prepared by microinjection of DNA into the pronuclei of fertilized goat oocyte and cultured in vitro. Pronuclear microinjected cell stage embryos were surgically transferred into the oviducts of the recipient at day 4 or 5 following removal, and morula to blastocyst stage embryos were surgically transferred into uterus at day 9. Pregnancy was diagnosed by transrectal ultrasound scanning at and 8 weeks following embryo transfer. The pregnancy rate was affected by several factors, such as estrus induction, the number of previous transfer, transfer site, stage of CL (corpus luteum), the number of recipient CL, stage of embryos and the number of transferred embryo. The pregnancy rate was significantly higher in recipients that came into estrus naturally than recipients that induced to come into estrus with (59.1% vs. 36.8%; P<0.05). The pregnancy rate was higher when the embryos were transferred into the left oviduct than transferred into the right oviduct (42.9% vs. 35.3%; P<0.05). The pregnancy rate of recipients with (early) stage corpus hemorrhagicum in ovary was hi틴or than recipient with (late) stage hemorrhagicum (47.5% vs. 17.9%; P<0.01). Higher pregnancy rates were obtained by transfer of 1-cell stage embryos into oviduct while late blastocysts (51.6% vs. 66.7%; P<0.01) into uterus. The pregnancy rates when 3 embryos were transferred to recipients were significantly higher than when 2 embryos we.e transferred (47.6% vs. 27.0%; P<0.05). Although there were no significant difference among the group, adhesion of reproductive organs, uterine size, ovulation rate of recipients, presence of large follicle and difficulty of transfer affected pregnancy rate of recipient. Higher pregnancy rates were obtained in the recipients with diameter uterine horn as compared to the recipients with <5m diameter or >20mm diameter uterine hem (38.9%, 20% vs. 18.2%), in the recipients with large follicle in the ovulated ovary ipsilaterally (53.6% vs. 37.1%) and in the transfer which was carried out easily (39.2% vs. 27.8%, 0%). In conclusion, the high rate of pregnancy was achieved following transfer of pronuclear microinjected embryos when three or four 1-cell stage embryos were transferred into oviduct with stage corpus hemorrhagicum in the ovary of recipient which came into estrus naturally.

18F-FDG Carotid PET CT is Predictive of Degree of Inflammation in Carotid Plaque

최윤석,윤호중,박정환,오수성,이동현,박철수,오용석,정욱성,정용안,손형선 한국지질동맥경화학회(구 한국지질학회) 2007 한국지질동맥경화학회 추계학술발표논문집 Vol.2007 No.-

1P-521 : 3D networked porous MoS₂ and its application to lithium ion battery anode

최윤석,유대종,김지만 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1

MoS₂ has superior electrochemical properties suit for lithium ion battery, such as high theoretical capacity (670 mAh/g), low volume expansion during cycle (~103%) and the week vdw forces between layers, which offers facile route for Li+. The lithium storage mechanism of MoS₂ is widely known as an irreversible intercalation reaction in the first cycle and reversible conversion reactions (MoS₂ + 4Li⁺ + 4e^- ↔ Mo + 2Li₂S). However, some recent studies contradict above mentioned pathway and suggest different reversible reaction path (Li₂S ↔ 2Li⁺ + S^2-), similar to the Li-S battery reaction. In order to clarify the reaction process, we synthesized ordered mesoporous MoS₂ as a model structure to ascertain the complete reaction by obtaining the maximum reversible capacity from this material. We also utilized synchrotron radiation based characterization techniques to directly observe local and bulk structural changes in the well-synthesized mesoporous MoS₂ during the electrochemical cycling.

적층제조 용융풀(Melt Pool) 모니터링 기술 개발 동향

최윤석,김재웅,이슬비 대한금속재료학회(구 대한금속학회) 2019 재료마당 Vol.32 No.5