• Title/Summary/Keyword: Hwang Do-Yeon

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Characteristics of Optimized Analytical Method of Hydrogen Cyanide in Cigarette Mainstream Smoke by Using Continuous Flow Analyzer(CFA) (Continuous Flow Analyzer(CFA)를 이용한 담배 주류연 중 Hydrogen Cyanide(HCN)의 최적 분석방법 구명)

  • Na, Seung-Ju;Eo, Sung-Je;Kim, Do-Yeon;Bock, Jin-Young;Hwang, Keon-Joong
    • Journal of the Korean Society of Tobacco Science
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    • v.31 no.1
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    • pp.39-44
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    • 2009
  • Hydrogen cyanide (HCN) is present in both the particulate and vapor phase of cigarette mainstream smoke. It is one of the 44 harmful substances on Hoffmann's list and is known to be a major ciliatoxic agent in cigarette mainstream smoke. Typically the determination of HCN in cigarette mainstream smoke has been done through colorimetric and electrochemical techniques, such as UV-spectrophotometry (UV), continuous flow analyzer (CFA), ion chromatography (IC) and capillary GC-ECD. In particular, CFA commonly has been using analysis hydrogen cyanide in cigarette smoke and the basic principle is pyridine-pyrazolone reaction. In this study, the more optimized analytical method is suggested isonicotinic acid-pyrazolone reaction method than previous pyridine-pyrazolone reaction method, a commonly used method for the determination of cyanide in water and air, by CFA. Sample collection was optimized by trapping particulate and vapor phase of smoke separately. The optimum NaOH concentration of the trapping solution was shown to be 0.2 M. HCN was stable up to 6 hours in this concentration but only 3 hours in 0.1 M solution. The sensitivity of this method was fairly good and it might be used in analysis of HCN in cigarette mainstream smoke.

Effects of Oxidation on the Order-disorder Transition in NiPt Alloy Nano Crystals

  • Seo, Ok-Gyun;Hwang, Jae-Seong;Song, Da-Hyeon;Lee, Ji-Yeon;Choe, Jeong-Won;Lee, Su-Ung;Gang, Hyeon-Cheol;No, Do-Yeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.253-253
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    • 2012
  • The effects of oxidation on the order-disorder transition in NiPt bimetallic alloy crystal have been investigated using in-situ synchrotron x-ray scattering technique. The temperature dependence of the crystal structure and the order parameter were measured during in-situ heating and cooling under vacuum and oxygen environments. The order-disorder transition temperature of NiPt alloy crystals in vacuum was between $615^{\circ}C$ and $627^{\circ}C$. On the other hand under oxygen environment, the transition temperature decreases by about $31^{\circ}C$ after the oxidation. The change of the transition temperature can be explained by the formation of NiO crust on the surface of NiPt crystal, which alters the composition of the Ni and Pt atoms. Since the transition temperature depends sensitively on the Ni-Pt composition, the transition temperature changes as Ni atoms diffuse out to form NiO.

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Sequential Approximate Optimization of Shock Absorption System for Lunar Lander by using Quadratic Polynomial Regression Meta-model (2차 다항회귀 메타모델을 이용한 달착륙선 충격흡수 시스템의 순차적 근사 최적설계)

  • Oh, Min-Hwan;Cho, Young-Min;Lee, Hee-Jun;Cho, Jin-Yeon;Hwang, Do-Soon
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.39 no.4
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    • pp.314-320
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    • 2011
  • In this work, optimization of two-stage shock absorption system for lunar lander has been carried out. Because of complexity of impact phenomena of shock absorption system, a 1-D constitutive model is proposed to describe the behavior of shock absorption system. Quadratic polynomial regression meta-model is constructed by using a commercial software ABAQUS with the proposed 1-D constitutive model, and sequential approximate optimization of two-stage shock absorption system has been carried out along with the constructed meta-model. Through the optimization, it is verified that landing impact force on lunar lander can be considerably reduced by changing the cell size and foil thickness of honeycomb structure in two-stage shock absorption system.

The effect of Gyungokgo-gamibang extract on hair growth and protein expression in mice (경옥고가미방 추출물이 생쥐의 양모 및 발모 관련 단백 발현에 미치는 영향)

  • Do, Eun-Ju;Hwang, Mee-Yul;Kim, Seung-Yeon;Lee, Jin-Sang;Yang, Dae-Seok;Yang, Chae-Ha;Kim, Mi-Ryeo
    • The Korea Journal of Herbology
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    • v.26 no.4
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    • pp.9-14
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    • 2011
  • Objective : Present study was carried out to investigate the effect of Gyungohkgo-gamibang extract on hair growth and protein expression in an alopecia model of C57BL/6 mice. Methods : Mice were divided into 3 experimental groups including normal (vehicle), Gyungohkgo-gamibang extract (YNS-10) and 5% minoxidil-treated group. The test materials were daily applied with 0.1 ml per mouse on shaved dorsal skin for 3 weeks. The hair growth was monitored by photograph at 5, 10, 15, 21 days after topical application. Then the changes of hair density and hair thickness in the hair-removed area were evaluated by phototrichogram using folliscope. Also the expression level of growth factors related to hair growth was measured by western blotting. Results : Application of minoxidil or YNS-10 stimulated the hair growth compared to vehicle treatment. Therefore hair density of minoxidil or YNS-10 application was increased about 200% and 210% more than in vehicle application on 14 day, respectively. And hair thickness of both minoxidil group and YNS-10 group was increased about 220% and 210 % more than in vehicle spreading on 14 day, respectively. Futhermore the protein expression of IGF-1 and VEGF were significantly up-regulated on 7 day in YNS-10 and minoxidil-spreaded group compared to vehicle-applied group. Conclusion : These data suggest that YNS-10 has potent stimulating activity on hair growth in C57BL/6 mice and potential usefulness as ingredients of hair tonic and hairrestore.

The Clinical Study of Lumbar Spinal Stenosis in Oriental Medical Hospital (요추관협착증의 한의학적 보존적 치료에 대한 임상적 고찰)

  • Hwang, Jae-Yeon;Do, Won-Seok
    • Journal of Acupuncture Research
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    • v.17 no.3
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    • pp.116-124
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    • 2000
  • This clinical study was carried out 15 cases with lumbar spinal stenosis patients, who had been admitted and diagnosed by Computed Tomography from June, 1999 to May, 2000, in the department of acupuncture and moxibustion. Hanseo University Oriental Medical Nospital. The results obtained from this study were as follows; 1. We investigated 10 female and 5 male patients. The age distribution was from early 20's to 70's, among which 30's and 50's were most common. 2. The most common duration of symptom was less than a year(46.7%). 3. Regarding to the number of the involved levels, one was 12 cases(80%), two was 3 cases(20.0%). In the one level cases, L4~5 was the most common involved site. 4. Regarding to the clinical symptoms, low back pain was the most common, followed by lower extremity radiating pain, intermittent claudication, lower extremity paresthesia. 5. In orthopaedic examinations, positive sign in Milgram test was 80.0%, positive sign in straight leg raising test was 40.0%, and positive sign in Braggard test was 33.3%. Inneurologic examinations, sensory loss was seen in 60.0%, motor weakness and decreased deep tendon reflex were 26.7% in each. 6. According to clinical symptom scale proposed by Chae(1989), grade I1I was the most common (53.3%), followed by grade II, grade IV, grade I . 7. According to treatment outcome scale proposed by Chae(1989), Good was the most common (73.3%), followed by Excelleat, Fair and Poor.

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Species Composition and Density of the Demersal Fishes on the Emperor Seamount in the Northwestern Pacific Ocean (북서태평양 황제해산해역 저어류의 종조성 및 자원밀도)

  • Kwon, Youjung;Hwang, Sun Do;Kim, Yeong Seung;Moon, Dae Yeon
    • Korean Journal of Ichthyology
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    • v.21 no.2
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    • pp.118-124
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    • 2009
  • A Korean trawl fishery was conducted on the Emperor Seamounts in the northwestern Pacific Ocean from 2005 to 2007. Total catches were 750 mt, 460 mt and 440 mt in 2005, 2006 and 2007, respectively. Splendid alfonsino (Beryx splendens) and North Pacific armorhead (Pseudopentaceros wheeleri) were dominant in the commercial fisheries on the Emperor Seamounts during 2005-2007. Biomass of each species was estimated by the swept area method from March 2005 to August 2007. During three years, average biomass of Splendid alfonsino and North Pacific armorhead were 791 mt and 266 mt, respectively.

Adaptive Situation of the wireless communication technology for the Medical Science Environment (무선정보통신기술의 의료과학 환경 적용현황 분석)

  • Hwang, Jin-Ok;Lee, Do-Yeon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.9
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    • pp.2100-2106
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    • 2015
  • Recently, we are increasing an interest of the health care from the developing elderly society. The need for the safety standardization is the High-tech industry that the technology of Medical science based on advanced nations with the wireless communication technology. It is urgent matter the chronic disease that is growing the total costs is everyday increased. We consider the standardization of the monitoring the medical examination based on the medical science environment with wireless communication technology. In addition, we make the environment of the powerful nation based on medical / patient care technology for the supporting of the high quality service. In this paper, we focus on description of the relationship that convergence of the medical / patient care science is need the component based on wireless communication technology.

Fabrication and Characterization of Ag Nanoparticle Dispersed Polymer Nanofiber and Ag Nanofiber Using Electrospinning Method (전기방사법을 이용한 Ag 나노입자 분산 고분자 나노파이버와 Ag 나노파이버 제조 및 특성 평가)

  • Kim, Hee-Taik;Hwang, Chi-Yong;Song, Han-Bok;Lee, Kun-Jae;Joo, Yeon-Jun;Hong, Seong-Jei;Kang, Nam-Kee;Park, Seong-Dae;Kim, Ki-Do;Cho, Yong-Ho
    • Journal of Powder Materials
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    • v.15 no.2
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    • pp.114-118
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    • 2008
  • Functional nanomaterial is expected to have improved capacities on various fields. Especially, metal nanoparticles dispersed in polymer matrix and metal nanofiber, one of the functional nanomaterials, are able to achieve improvement of property in the electric and other related fields. In this study, the fabrication of metal (Ag) nanoparticle dispersed nanofibers were attempted. The Ag nanoparticle dispersed polymer nanofiber and Ag nanofiber were fabricated by electrospinning method using electric force. First, PVP/$AgNO_3$ nanofibers were synthesized by electrospinning in $18{\sim}22kV$ voltage with the starting materials (Ag-nitrate) added polymer (PVP; poly (vinylpyrrolidone)). Then Ag nanoparticle dispersed polymer nanofibers were fabricated to reduce hydrogen reduction at $150^{\circ}C$ for 3hr. And Ag nanofibers were synthesized by the decomposited of PVP at $300{\sim}500^{\circ}C$ for 3hr. The nanofibers were analyzed by XRD, TGA, FE-SEM and TEM. The experimental results showed that the Ag nanofibers could be applied in many fields as an advanced material.

Creation of an Ethanol-Tolerant Yeast Strain by Genome Reconstruction Based on Chromosome Splitting Technology

  • Park, A-Hwang;Sugiyama, Minetaka;Harashima, Satoshi;Kim, Yeon-Hee
    • Journal of Microbiology and Biotechnology
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    • v.22 no.2
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    • pp.184-189
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    • 2012
  • We sought to breed an industrially useful yeast strain, specifically an ethanol-tolerant yeast strain that would be optimal for ethanol production, using a novel breeding method, called genome reconstruction, based on chromosome splitting technology. To induce genome reconstruction, Saccharomyces cerevisiae strain SH6310, which contains 31 chromosomes including 12 artificial mini-chromosomes, was continuously cultivated in YPD medium containing 6% to 10% ethanol for 33 days. The 12 mini-chromosomes can be randomly or specifically lost because they do not contain any genes that are essential under high-level ethanol conditions. The strains selected by inducing genome reconstruction grew about ten times more than SH6310 in 8% ethanol. To determine the effect of mini-chromosome loss on the ethanol tolerance phenotype, PCR and Southern hybridization were performed to detect the remaining mini-chromosomes. These analyses revealed the loss of mini-chromosomes no. 11 and no. 12. Mini-chromosome no. 11 contains ten genes (YKL225W, PAU16, YKL223W, YKL222C, MCH2, FRE2, COS9, SRY1, JEN1, URA1) and no. 12 contains fifteen genes (YHL050C, YKL050W-A, YHL049C, YHL048C-A, COS8, YHLComega1, ARN2, YHL046W-A, PAU13, YHL045W, YHL044W, ECM34, YHL042W, YHL041W, ARN1). We assumed that the loss of these genes resulted in the ethanol-tolerant phenotype and expect that this genome reconstruction method will be a feasible new alternative for strain improvement.

Thermal Vacuum Test of Kaistsat-4 Qm (과학위성 1호 인증모델 열진공 시험)

  • Kim, Do-Hyeong;Jeong, Yeon-Hwang;Tak, Gyeong-Mo;Lee, Jun-Ho;Cha, Won-Ho;Lee, Sang-Hyeon;Choe, Seok-Won;Mun, Gwi-Won
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.1
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    • pp.120-124
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    • 2003
  • KAISTSAT- 4, an experimental small satellite, is being developd by Satellite Technology Research Center in KAIST as a sequel mission to KITSAT-1, 2, and 3. The flight model scheduled to be launched in 2003, the qualification model construction and testing have been completed recently. The satellite subsystems of the qualification model have been tested under a thermal vacuum environment harsher than expected in the orbit. Thermal balance test has also been done in order to evaluate and tune the thermal analysis model of the qualification model. This paper describes the thermal vacuum test procedure, the results, as well as the lessons learned during the tests, which can be useful for future thermal vacuum tests of small satellites.