• Composites Research
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• 제18권1호
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• pp.23-29
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• 2005

본 연구에서는 몬모릴로나이트(montmorillonite, MMT)의 오존처리가 몬모릴로나이트의 표면특성과 폴리프로필렌(polypropylene, PP) 나노복합재료의 열안정성에 미치는 영향에 대하여 살펴보았다. MMT의 표면 특성은 XRD, FT-IR 그리고 XPS를 통해 관찰하였고, 나노복합재료의 열안정성은 열중량 분석기(TGA)를 이용하여 조사하였다 실험 결과, 실리케이트의 층간 간격은 유기적으로 개질된 MMT(D-MMT)가 개질되지 않은 MMT에 비해 약 11${\AA}$ 증가한 것을 알 수 있었고, FT-IR 결과로부터 D-MMT의 경우 $2800\~2900\;cm^{-1}$ 부근에서 $CH_2$의 피크가 형성된 것을 확인할 수 있었다. 또한 오존처리는 MMT 표면에 Si-O와 $SiO_2$ 관능기를 증가시켰는데, 이는 산소를 포함하는 관능기들이 발달하기 때문으로 판단된다. 오존처리된 MMT가 도입된 나노복합재료에서 열안정성이 증가하는 것을 확인할 수 있었으며, 이는 PP와 MMT 사이의 산-염기 계면 상호작용으로부터 계면 결합력이 향상되었기 때문으로 판단된다.

• 보존과학회지
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• 제29권2호
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• pp.103-110
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• 2013

1900년대 초반에는 얇은 책의 제본에 스테이플러를 많이 이용하였다. 이러한 책들에서는 스테이플러의 심주위로 종이의 변색 및 바스라짐 현상이 관찰된다. 본 연구는 종이의 변색을 일으키는 물질의 동정 및 원인 규명을 목적으로 한다. 종이의 상태 관찰에는 광학현미경, SEM, 원소분석에는 EDX, 화학구조의 파악에는 FT-IR을 이용하였다. 또한 변색 원인 규명을 위하여, 5종류의 종이에 스테이플러 심을 박아 열화 실험을 행하였다. 그 결과, 스테이플러 심으로 사용되는 철의 산화물의 일종이 종이를 갈색으로 변색 시키며, 종이의 섬유를 짧아지게 하였다. 종이가 변색된 부분에서는 Fe가 높게 검출되었으며, FT-IR 분석 결과 $Fe_2O_3$로 밝혀졌다.

• 한국재료학회지
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• 제26권3호
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• pp.130-135
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• 2016

To alloy high melting point elements such as boron, ruthenium, and iridium with copper, heat treatment was performed using metal oxides of $B_2O_3$, $RuO_2$, and $IrO_2$ at the temperature of $1200^{\circ}C$ in vacuum for 30 minutes. The microstructure analysis of the alloyed sample was confirmed using an optical microscope and FE-SEM. Hardness and trace element analyses were performed using Vickers hardness and WD-XRF, respectively. Diffusion profile analysis was performed using D-SIMS. From the microstructure analysis results, crystal grains were found to have formed with sizes of 2.97 mm. For the copper alloys formed using metal oxides of $B_2O_3$, $RuO_2$, and $IrO_2$ the sizes of the crystal grains were 1.24, 1.77, and 2.23 mm, respectively, while these sizes were smaller than pure copper. From the Vickers hardness results, the hardness of the Ir-copper alloy was found to have increased by a maximum of 2.2 times compared to pure copper. From the trace element analysis, the copper alloy was fabricated with the expected composition. From the diffusion profile analysis results, it can be seen that 0.059 wt%, 0.030 wt%, and 0.114 wt% of B, Ru, and Ir, respectively, were alloyed in the copper, and it led to change the hardness. Therefore, we verified that alloying of high melting point elements is possible at the low temperature of $1200^{\circ}C$.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2011년도 춘계학술발표대회
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• pp.346-349
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• 2011

In this paper, we design a perceptually invisible dot pattern layout and its recognition scheme, and we apply the recognition scheme into a smart self learning aid for interactive learning aid. To increase maximum information capacity and also increase robustness to the noises, we design a ECC (error correcting code) based dot pattern with directional vector indicator. To make a smart self-learning aid, we embed the micro dot pattern (20 information bit + 15 ECC bits + 9 layout information bit) using K ink (CMYK) and extract the dot pattern using IR (infrared) LED and IR filter based camera, which is embedded in the smart pen. The reason we use K ink is that K ink is a carbon based ink in nature, and carbon is easily recognized with IR even without light. After acquiring IR camera images for the dot patterns, we perform layout adjustment using the 9 layout information bit, and extract 20 information bits from 35 data bits which is composed of 20 information bits and 15 ECC bits. To embed and extract information bits, we use topology based dot pattern recognition scheme which is robust to geometric distortion which is very usual in camera based recognition scheme. Topology based pattern recognition traces next information bit symbols using topological distance measurement from the pivot information bit. We implemented and experimented with sample patterns, and it shows that we can achieve almost 99% recognition for our embedding patterns.

• Elastomers and Composites
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• 제37권4호
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• pp.258-264
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• 2002

본 연구에서는 열처리에 의한 실리카의 표면특성과 실리카/폴리우레탄 복합재료의 기계적 계면물성에 대하여 고찰하였다. 열처리에 의한 실리카의 표면특성은 Fourier Transform-IR(FT-IR), Solid-state 29Si NMR spectroscopy, 그리고 접촉각을 통하여 알아보았으며 실리카/폴리우레탄 복합재료의 기계적 계면물성은 인열에너지 (GIIIC)를 측정하여 관찰하였다. 본 실험결과, 열처리 온도가 증가함에 따라 실리카의 Si-OH가 축합하여 Si-O-Si를 형성하고 표면자유에너지의 비극성 요소가 증가하는 것을 확인할 수 있었다. 이러한 결과로부터, 증가된 실리카의 표면자유에너지의 비극성요소는 폴리우레탄 내에 실리카의 분산성을 향상시켜 결과적으로 실리카/폴리우레탄 복합재료의 기계적 계면물성인 인열에너지가 증가된 것으로 사료된다.

• 한국전자통신학회논문지
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• 제7권2호
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• pp.439-445
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• 2012

IT융합기술은 점차적으로 인간 중심적, 저탄소 녹색성장을 모토로 하여 진화하고 있다. 증강현실 기술이란 현실 세계의 감각을 유지하면서 가상의 객체를 혼합할 수 있는 융합콘텐츠 기술이다. 시스템과 사용자 사이의 상호작용이 가능하고, 다양한 응용을 할 수 있으며, 확장성이 매우 높다. 본 논문에서는 기존의 상호작용에 대한 범위를 확장하기 위해 상황적 UX 기반의 스마트 증강현실 시스템을 제안하고자 한다. 실세계 환경 변화에 반응하는 가상 객체를 생성할 수 있는 시스템으로써 사용자는 본인의 개인적인 취향을 직접 가상 객체에 적용할 수 있다. 또한 다수의 가상 객체를 한꺼번에 영상 정합할 수 있으며, 조명의 밝기에 따라 낮과 밤에 해당하는 애니메이션을 보여주기도 한다. 이와 같이 복합적인 사용성을 갖는 시스템을 통해 사용자의 만족도를 높이고, 증강현실 콘텐츠에 대한 지속적인 사용을 유도할 수 있도록 한다.

• 한국전기전자재료학회논문지
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• 제30권9호
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• pp.577-582
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• 2017

The white light of a hybrid LED is obtained by using red and green organic fluorescent layers made of polymethylmethacrylate (PMMA) films, which function as color down-conversion layers of blue light-emitting diodes. In this research, we studied the fluorescence properties of a red organic fluorophore, employing perylene bisimide derivatives applicable to hybrid LEDs. The solubility, thermal stability, and luminous efficiency are important characteristics of organic fluorophores for use in hybrid LEDs. The perylene fluorescent compounds (1A and 1B) were prepared by the reaction of 4-bromophenol and 4-iodophenol with N,N'-bis(4-bromo-2,6-diisopropylphenyl)-1, 6,7,12-tetrachloroperylene-3,4,9,10-tetracarboxyl diimide (1) in the presence of dimethyl formaldehyde (DMF) at $70^{\circ}C$. The synthesized derivatives were characterized by using $^1H-NMR$, FT-IR, UV/Vis absorption and PL spectra, and TGA analysis. Compounds 1A and 1B showed absorption and emission at 570 nm and 604 nm in the UV/Vis spectrum. We also documented favorable solubility and thermal stability characteristics of the perylene fluorophores in our work. Perylene fluorophore 1, with the 4-bromophenol substituent 1A, exhibited particularly good thermal stability and solubility in organic solvents.

• 한국전기전자재료학회논문지
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• 제30권1호
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• pp.48-53
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• 2017

We report the studies on the red organic phosphor by using perylene bisimide derivatives. Even though perylene bisimide derivatives have excellent thermal stability and luminous efficiency, they have low solubility in organic solvents. In this research, modified perylene bisimide derivative, N,N'-Bis(4-bromo-2, 6-diisopropylphenyl)-1, 6, 7, 12-tetraphenoxyperylene-3, 4, 9, 10-tetracarboxyl bisimide (1C), has been prepared by the reaction of phenol with N,N'-Bis(4-bromo-2, 6-diisopropylphenyl)-1, 6, 7, 12-tetrachloroperylene-3, 4, 9, 10-tetracarboxyl bisimide (1B) in presence of DMF, at $70^{\circ}C$. The synthesized (1C) was characterized by using $^1H-NMR$, FT-IR, UV/V is spectroscopy, and TGA. The absorbtion and emission of (1C) was shown at 576 nm and 610 nm in UV/V is spectrum. In TGA thermogram, (1C) showed good thermal stability without significant weight loss to $220^{\circ}C$. And in the solubility analysis, (1C) with phenoxy group showed the good solubility in general organic solvents. The blended films of (1C) with PMMA (polymethyl methacrylate) at different weight % concentration such as 10, 5, 1 weight % have been prepared. The blended film was shown at 616 nm when monitored at 450 nm in PL emission spectra.

• 한국토양비료학회지
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• 제49권1호
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• pp.53-59
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• 2016

This study deals with the distribution of the clay minerals separated from clay fractions of ranch pastures in Korea and their chemical and mineralogical properties. Crystalline phases of the clay minerals were identified by powder X-ray diffraction (XRD) pattern and FT-IR spectra, and their relative chemical compositions were also analyzed by X-ray flourescence spectrometry (XRF). Primary minerals consisted mainly of quartz and mica and chlorite and kaolinite along with a trace of swelling micas were identified as secondary clay minerals. However, the relative content of these clay minerals was different with the locations, which led to significant effects on physical and chemical properties of soils like inorganic elemental composition. In particular, $SiO_2$ content was higher in Gochang ranch pasture than in other ranch pasture. Infrared (IR) spectra did not indicate any significant differences in organic functional groups among the locations. This study clearly showed that ranch pastures had different relative content of clay minerals and chemical properties depending on the location and consequently that those properties are worthy to be taken into account for soil amendment.

• Advances in Traditional Medicine
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• 제9권4호
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• pp.315-319
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• 2009

In present study evaluate the analgesic and anti-inflammatory activity of the compound obtained from the petroleum ether (40 - 60$^{\circ}C$) extract of the fruits from Dregea volubilis in Swiss albino mice and in Wister albino rats respectively. Dried and crushed fruits of Dregea volubilis were extracted by petroleum ether (40 - 60$^{\circ}C$), the proper solvent system was developed by TLC and subjected to column chromatography for obtaining the pure compound/s. IR, MASS, NMR (PMR, C13 NMR and DEPT) spectroscopic analysis were done to elucidate the structure of the compound/s. The petroleum ether (40 - 60$^{\circ}C$) extract of the fruits of Dregea volubilis led to isolation of a pentacyclic triterpenoid designated as taraxerone and characterized as D- friedoolean- 14- en, 3 one. Taraxerone had been screened for analgesic activity in Swiss albino mice and anti-inflammatory activity in Wister albino rats at the dose of 5 mg/kg body weight orally and exhibit significant analgesic and anti-inflammatory properties.