• 폴리머
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• 제29권3호
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• pp.221-230
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• 2005

복합재료에 있어서 계면상호작용과 상계면은 이를 구성하고 있는 성분의 함량이나 형태 또는 구조와는 관계없이 입자가 충전된 고분자 또는 고분자 블렌드, 섬유강화 복합재료, 나노복합재료 그리고 생체재료 등의 기본적 물성에 매우 중요한 역할을 한다 계면접착에 영향을 미치는 주요 성분들의 역할에 대한 인식과 이에 따른 적절한 표면처리는 관련기술로의 적용뿐만 아니라 다른 여러 연구 및 개발 분야에도 중요한 기술적 진보를 가져다준다. 그러나 모든 복합재료에서 계면과 상계면의 역할이 중요할지라도 이러한 표면처리 방법은 특정 시스템의 특성뿐만 아니라 그 목적에 맞게 적절하게 선택되어야 한다. 본 연구에서는 복합재료 시스템의 두 성분간의 계면상호작용을 향상시켜 최종 복합재료의 요구 물성을 증가시키기 위하여 여러 종류의 표면처리를 행하였으며, 그 결과들에 대하여 고찰하였다.

• 임상간호연구
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• 제21권1호
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• pp.43-52
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• 2015

Purpose: This study was aimed to develop the multicomponent intervention for preventing delirium among postoperative patients in a surgical intensive care unit (SICU). Methods: Using a quasi-experimental pre & post-test design with a non-equivalent control group, a total of 88 hospitalized patients in a SICU participated in this study. The 44 patients were allocated in each experimental and control group. The experimental group received the multicomponent intervention for delirium prevention including a delirium assessment and nursing intervention using a checklist, whereas the control group was provided with a standard care. The primary outcome of this study was the delirium incidence during the course of hospitalization. Results: There were no significant differences in the demographic and clinical characteristics between the two groups. The delirium occurred in 19.2% in the experimental group, whereas 38.6% in the control group ($x^2=4.526$, p<.05). Conclusion: The findings of the study demonstrated an effect of the multicomponent delirium prevention intervention in decreasing the delirium incidence rate over the standard care among the patients in SICU.

• 한국재료학회지
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• 제21권7호
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• pp.371-376
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• 2011

We report on the effects of $TiO_2$ doping power on the characteristics of multicomponent $TiO_2$-ITO (TITO) electrodes prepared by a multi-target sputtering system with tilted cathode guns. Both as-deposited and annealed TITO electrodes showed linearly increased sheet resistance and resistivity with increasing $TiO_2$ doping power. However, the TITO electrodes exhibited a fairly high optical transmittance regardless of the $TiO_2$ doping power due to the high transparency of the $TiO_2$. Although the annealed TITO showed much lower sheet resistance and resistivity relative to the as-deposited samples, the electrical properties of the annealed samples exhibited similar dependence on the $TiO_2$ power to the as-deposited samples. In addition, it was found that doping of an anatase $TiO_2$ in the ITO electrode prevented the preferred (222) orientation of the TITO electrodes. Although the TITO electrode showed higher sheet resistance and resistivity than that of the pure ITO electrode, it offers a very smooth surface and usage of a low-cost Ti element. It is thus considered a promising multicomponent transparent conducting electrode for cost-efficient flat panel displays and photovoltatics.

• Journal of Ginseng Research
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• 제43권1호
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• pp.27-37
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• 2019

Background: The structural conversions in ginsenosides induced by steaming or heating or acidic condition could improve red ginseng bioactivities significantly. In this paper, the chemical transformations of red American ginseng from fresh Panax quinquefolium L. under steaming were investigated, and the possible mechanisms were discussed. Methods: A method with reversed-phase high-performance liquid chromatography coupled with linear ion trap mass spectrometry ($HPLC-MS^n$)-equipped electrospray ionization ion source was developed for structural analysis and quantitation of ginsenosides in dried and red American ginseng. Results: In total, 59 ginsenosides of protopanaxadiol, protopanaxatriol, oleanane, and ocotillol types were identified in American ginseng before and after steaming process by matching the molecular weight and/or comparing $MS^n$ fragmentation with that of standards and/or known published compounds, and some of them were determined to be disappeared or newly generated under different steaming time and temperature. The specific fragments of each aglycone-type ginsenosides were determined as well as aglycone hydrated and dehydrated ones. The mechanisms were deduced as hydrolysis, hydration, dehydration, and isomerization of neutral and acidic ginsenosides. Furthermore, the relative peak areas of detected compounds were calculated based on peak areas ratio. Conclusion: The multicomponent assessment of American ginseng was conducted by $HPLC-MS^n$. The result is expected to provide possibility for holistic evaluation of the processing procedures of red American ginseng and a scientific basis for the usage of American ginseng in prescription.

• 한국분말재료학회지
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• 제26권5호
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• pp.375-382
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• 2019

Homogeneous multicomponent indium gallium zinc oxide (IGZO) ceramics for transparent electrode targets are prepared from the oxides and nitrates as the source materials, and their properties are characterized. The selected compositions were $In_2O_3:Ga_2O_3:ZnO$ = 1:1:2, 1:1:6, and 1:1:12 in mole ratio based on oxide. As revealed by X-ray diffraction analysis, calcination of the selected oxide or nitrides at $1200^{\circ}C$ results in the formation of $InGaZnO_4$, $InGaZn_3O_6$, and $InGaZn_5O_8$ phases. The 1:1:2, 1:1:6, and 1:1:12 oxide samples pressed in the form of discs exhibit relative densities of 96.9, 93.2, and 84.1%, respectively, after sintering at $1450^{\circ}C$ for 12 h. The $InGaZn_3O_6$ ceramics prepared from the oxide or nitrate batches comprise large grains and exhibit homogeneous elemental distribution. Under optimized conditions, IGZO multicomponent ceramics with controlled phases, high densities, and homogeneous microstructures (grain and elemental distribution) are obtained.

• 한국광물학회지
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• 제29권3호
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• pp.155-165
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• 2016

붕소가 포함된 다성분계 규산염 용융체의 원자 구조를 규명하는 것은 화산의 분화 양상을 포함한 다양한 지구화학적 과정의 원자 단위 기작을 밝히는데 중요하다. 붕소를 포함한 소듐 알루미노규산염 용융체의 붕소 및 알루미늄 주위의 원자 환경에 관한 자세한 정보는 수용액과 핵폐기물 유리(nuclear waste glasses)의 반응도(reactivity)에 대한 미시적인 설명을 제공한다. 본 연구에서는 붕소가 포함된 비정질 물질의 원자 구조 규명에 가장 적합한 고상 핵자기 공명 분광분석(solid-state nuclear magnetic resonance, solid-state NMR)을 이용하여 붕소의 함량이 비정질 소듐 보레이트($Na_2O-B_2O_3$)와 붕소를 포함한 다성분계 규산염 용융체[말린코아이트(malinkoite, $NaBSiO_4$)와 네펠린(nepheline, $NaAlSiO_4$)의 유사 이원계]의 원자 구조에 미치는 영향을 규명하였다. 비정질 소듐 보레이트의 $^{11}B$ MAS NMR 스펙트럼을 통해 붕소의 함량이 증가함에 따라 배위수가 3인 붕소($^{[3]}B$)가 증가한다는 것이 확인되었다. 비정질 말린코아이트와 네펠린의 유사 이원계의 $^{11}B$ MAS NMR 스펙트럼을 통해 $X_{Ma}$ [$=NaBSiO_4/(NaBSiO_4+NaAlSiO_4)$]가 증가함에 따라 배위수가 4인 붕소($^{[4]}B$)는 증가하는 반면 $^{[3]}B$는 감소하는 것이 관찰되었다. 다성분계 용융체의 $^{27}Al$ MAS NMR 실험 결과, 모든 조성의 용융체에서 배위수가 4인 알루미늄($^{[4]}Al$) 피크가 지배적으로 나타났다. 또한 네펠린 용융체에 붕소가 첨가되었을때 $^{[4]}Al$ 피크의 폭이 크게 감소하였고, 이는 붕소의 첨가가 네펠린 용융체 내의 알루미늄 주위의 구조적 위상학적 무질서도를 감소시킨다는 것을 지시한다. 붕소를 포함한 이원계 및 다성분계 비정질 물질의 $^{11}B$ MAS NMR 스펙트럼으로부터 시뮬레이션을 하여 붕소의 함량에 따른 붕소 원자 환경의 상대적인 존재비를 정량적으로 분석하였고, 이 결과는 붕소가 포함된 비정질 물질의 거시적 성질 변화에 대한 미시적 기작의 근원을 제시할 가능성을 보여준다.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2013년도 춘계학술대회 논문집
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• pp.168-168
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• 2013

• Bulletin of the Korean Chemical Society
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• 제30권8호
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• pp.1877-1880
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• 2009

• 한국막학회:학술대회논문집
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• 한국막학회 2004년도 Proceedings of the second conference of aseanian membrane society
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• pp.11-11
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• 2004

Under the coordination of GKSS a new European project in the field of membrane development started recently. This project focuses on the development of novel nanostructured materials for selective material transport and separation. Two classes of materials will be developed in this project: nanostructured organic/inorganic hybrid materials and functional self-organized supramolecular copolymers.(omitted)

• 한국연소학회:학술대회논문집
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• 한국연소학회 2005년도 제31회 KOSCO SYMPOSIUM 논문집
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• pp.120-131
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• 2005

The evaporation characteristics of single and multicomponent droplets hanging at the tip of a quartz fiber are studied experimentally at the different environmental conditions under normal gravity. Heptane and Hexadecane are selected as two fuels with different evaporation rates and boiling temperatures. At the first step, the evaporation of single component droplet of both fuels has been examined separately. At the next step the evaporation of several blends of these two fuels, as a binary component droplet, has been studied. The temperature and pressure range is selected between 400 and 700 $^{\circ}C$, and 0.1 and 2.5 MPa, respectively. High temperature environment has been provided by a falling electrical furnace. The initial diameter of droplet was in range of 1.1 and 1.3 mm. The evaporation process was recorded by a high speed CCD camera. The results of binary droplet evaporation show the three staged evaporation. In the the first stage the more volatile component evaporates. The droplet temperature rises after an almost non evaporating period and in the third stage a quasi linear evaporation takes place. The evaporation of the binary droplet at low pressure is accompanied with bubble formation and droplet fragmentation and leads to incomplete microexplosion. The component concentration affects the evaporation behavior of the first two stages. The bubble formation and droplet distortion does not appear at high environment pressure. Nomenclature