• 대한임상독성학회지
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• 제3권1호
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• pp.60-62
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• 2005

A previously healthy 57-year-old woman with dyspnea and wheezing presented to the emergency department a few minutes after exposure to unknown gas from mixing bleach (sodium hypochlorite) and cleaning agent (hydrochloric acid) at work place. Initial physical examination revealed severe wheezing on both whole lung fields, but the chest radiograph was normal. Arterial blood gas analysis showed only moderate hypoxemia. The patient was treated with oxygen, $\beta$adrenergic bronchodilators, antihistamines and corticosteroids, after then symptoms were improved. And the patient discharged against medical advice. We report a rare case of reactive airways dysfuntion syndrome from chlorine gas exposure.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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• pp.369-374
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• 1997

This study is the experimental results on the flowing properties of the super flowing concrete (SFC) using limestone (LS), which is to develop the SFC in level of ordinary strength. And this study is described with respect to basic concept, confined water ratio ($\beta_p$) of binder (cement+limestone) in paste, relationship between volume ratio of water-binder (w/b) and addition ratio of superplasticizer in mortar, flowing velocity and funneling time and compressive strength in concrete to replacement ratio of LS. The results of this study is improved to flowing properties in fleshly concrete with increasing replacement ratio of LS. The optimal mixing condition of the SFC using LS in level of ordinary strength is proved W/C 55%, LS 40% and W/C 60%, LS 50%.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2002년도 제25회 KOSCI SYMPOSIUM 논문집
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• pp.11-17
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• 2002

The first-order conditional moment closure (CMC) model is applied to $CH_4$/Air turbulent jet diffusion flames(Sandia Flame D, E and F). The flow and mixing fields are calculated by fast chemistry assumption and a beta function pdf for mixture fraction. Reacting scalar fields are calculated by elliptic CMC formulation. The results for Flame D show reasonable agreement with the measured conditional mean temperature and mass fractions of major species, although with discrepancy on the fuel rich side. The discrepancy tends to increase as the level of local extinction increases. Second-order CMC may be needed for better prediction of these near-extinction flames.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1091-1092
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• 2006

Silicon nitride - silicon carbide composite was developed by using an abrasive SiC powders as a raw material. The composites were prepared by mixing abrasive SiC powder with silicon, pressing and sintering at $1400^{\circ}C$ under nitrogen atmosphere in atmosphere controlled vacuum furnace. The proportion of silicon in the initial mixtures varied from 20 to 50 wt%. After sintering, crystalline phases and microstructure were characterized. All composites consisted of ${\alpha}-Si_3N_4$ and ${\beta}-Si_3N_4$ as the bonding phases in SiC matrix. Their physical and mechanical properties were also determined. It was found that the density of the obtained composites increased with an increase in the $Si_3N_4$ content formed in the reaction.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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• pp.278-284
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• 1997

This study dealt with the flowing properties of the super flowing concrete for class F fly ash producted thermal power plant and the application for concrete industry. For this purpose, fly ash is analyzed for confined water ratio($\beta_p$)and the super flowing concrete is tested the flowing properties including flowing velocity, funneling time, height difference of box test and compressive strength. As the result, in order to satisfy the flowing properties of the super flowing concrete using class F fly ash, the optimum mixing conditions are determined water-bindrer ratio 37$\pm$2%, volume ratio of fine aggregates(Sr) 47$\pm$2% and coarse aggregates(Gv) 51$\pm$1%.

• 한국세라믹학회지
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• 제31권4호
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• pp.399-406
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• 1994

The SiC/MoSi2 composite material was prepared by infiltration with the mixture of metal Si and MoSi2 into the preform of $\alpha$-SiC and graphite under the vacuum atmosphere of 10-1 torr. The mechanical properties, phases and microstructural characteristics have been investigated by employing an universal testing machine, scanning electron microscope and X-ray diffractometer. With the increase of MoSi2/Si mixing content, the quantity of the residual silicon phase was decreased and the hardness and fracture toughness of composite materials were increased. Also, as the infiltration temperature increased, a lot of fine-grained $\beta$-SiC phases, which were produced from the reaction of graphite and liquid silicon melt, were transformed to $\alpha$-SiC phases.

• 한국염색가공학회지
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• 제9권6호
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• pp.18-25
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• 1997

The change of crystalline structure and mechanical properties of i-PP films which had before isothermally annealed at various temperature and times have been studied. The following results were abtain The crystallinity and crystallite size of the samples showed increasing above the annealing temperature of 13$0^{\circ}C$ and these are equilibrated after an annealing time of 30min. When the crystalline form was at annealling condition were below 13$0^{\circ}C$, 2min, subsequently achieving an $\alpha$, $\beta$ mixing form and at 13$0^{\circ}C$, 10min, the crystalline form entered an $\alpha$ form transition. It is achieved a typical $\alpha$ form at 15$0^{\circ}C$. The value of T'm was increasing until 13$0^{\circ}C$ but it was not founded at 15$0^{\circ}C$. The slopes which represented crystalline form in an Avrami plot differed from each other within the range of this experiment.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2012년도 춘계학술발표회 논문집
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• pp.254-254
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• 2012

The purposed of this work was to determine surface charateristics of anodized Ti-30Nb-xTa alloys with Ta content. Samples were prepared by arc melting, followed by followed by homogenization for 12 hr at $1000^{\circ}C$ in argon atmosphere. The electrolyte for anodization treatment was prepared by mixing 465ml $H_2O$ with 35M $H_3PO_4$ and anodized at 180V to 220V. The microstructures of the alloys were examined by X-ray diffractometer (XRD) and optical microscopy (OM). Surface characteristics of anodized Ti-30Nb-xTa alloys was investigated by potentiodynamic test and potentiostatic in 0.9% Nacl solution at $36.5{\pm}1^{\circ}C$. It was observed that the changed ${\alpha}$ phase to ${\beta}$ phase with Ta content.

• 대한화장품학회지
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• 제37권4호
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• pp.337-345
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• 2011

약용식물은 피부와 모발을 보호하는 잠재적 기능을 가지고 있다고 알려져 있다. 약용식물의 유용 성분들은 대부분 비수용성 약용성분들이므로 수용성 분자 담지체인 ${\beta}$-cyclodextrin을 이용하여 초분자 복합체를 형성시켜 기능성의 변화를 살펴보았다. 약용식물의 유용 성분이 함유된 크림, 샴푸, 바디워시, 그리고 헤어토닉은 계면활성제, 방향제, 약용식물 추출물과 ${\beta}$-cyclodextrin을 혼합하여 제조하였다. 복합체를 함유한 샴푸 및 바디워시에서 그람 양성균들과 비듬균으로 알려져 있는 효모에 대한 항균활성과 균 성장억제 효과를 확인하였다. HDF (human dermal fibroblast)에 대한 초분자체의 독성실험결과, 초분자체의 함량이 1 mg/mL 이하의 경우에서는 세포 독성이 나타나지 않았다. 본 연구결과는 약용식물 추출물과 약용성분 초분자 복합체에 대한 세포무독성을 확인하고 항균활성을 확인함으로써 향후 기능성화장품 제조 시 안정성과 기능성의 과학적 근거를 확보하였다고 사료된다.

• 한국안광학회지
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• 제14권1호
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• pp.47-56
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• 2009

목적: 시감도가 최적화된 투과필터의 칼라위치를 추정한다. 방법: 시감도 최적화를 위한 칼라를 Y(Yellow), G(green)과 P(Red)를 이용하여 CR-39에 담그기 법으로 $Y_{1-x}G_{x}$, $Y_{1-x}P_{x}$를 제작하였다. 투과광에서 최종 비시감도의 추정방법 모델은 파장에 따른 눈의 시감도와 렌즈의 투과율 세기의 곱($P_f$ ($P_f({\lambda}=T({\lambda}){\cdot}P({\lambda}).)$.)으로 나타낸다. 400~700 nm 영역에서 투과광의 평가는 비시감도 곡선의 면적, Peak, 폭, 최고높이 값으로 평가한다. 결과: $Y_{1-x}G_{x}$에서 x=0.04, x=0.08, x=0.10, x=0.12, x=0.14, x=0.5에서 ${\beta}=S_1/S_0{\cdot}100$ 값은 각각 76.1, 77.9, 80.7, 81.6, 80.2, 18.6을 갖는다. $Y_{1-x}P_{x}$에서 x=1.00, x=0.2, x=0.6, x=0.8에서 ${\beta}=S_1/S_0{\cdot}100$ 값은 각각 74.3, 74.0, 70.5, 33.0을 갖는다. 투과광의 면적과 최고높이를 평가한 결과는 $Y_{1-x}P_{x}$보다 $Y_{1-x}G_{x}$가 더 큰 값을 갖게 되어 비시감도 최적화에 접근하였다. 결론: 비시감도 최적화는 $Y_{1-x}G_{x}$에서 X=0.12~0.14의 값을 갖는다.