• 분석과학
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• 제29권6호
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• pp.283-292
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• 2016

범죄현장조사에 사용되는 인체에 유해할 수 있는 일반분말에 대한 대체수단으로 천연분말(오징어 먹물분말, 청대분말, 쌀분말)을 이용하여 비 다공성표면(유리, 플라스틱, 타일)상의 잠재지문을 현출(가시화)하였다. 현출된 잠재지문을 Automatic Fingerprint Identification System (AFIS)으로 분석한 특징점의 수를 흑색분말을 사용한 결과 특징점 수와 비교하였으며 또한 객관적이고 계량적인 평가방법의 개발을 위하여 각 분말로 가시화된 지문의 이미지를 농도계 이미지분석(densitometric image analysis)을 이용한 결과 값인 융선 피크의 면적값을 비교하였다. 천연분말들의 현출효과는 표면에 따라 다양하게 나타났다. 일반적으로 오징어 먹물분말은 대부분의 표면에서 좋은 현출을 보였으며 청대분말은 타일표면에서 그리고 쌀분말은 유리표면에서 최고의 현출을 보였다. 그러나 플라스틱 표면은 천연분말에 의한 지문현출이 가장 어려운 표면이었다. Field Emission Scanning Electron Microscope (SEM)를 이용한 이미지 분석에서 융선에 적절한 흡착력을 가지는 조건으로 천연분말 입자의 크기와 형태가 중요한 인자임을 확인할 수 있었다. 비록 기술적인 어려움으로 특징점의 수와 융선 피크의 면적값과의 상관관계를 볼 수는 없었으나 공평하고 객관적인 지문의 평가방법으로 기준 이미지의 사용을 통한 이미지 보정을 통하여 가능하리라고 사료된다. 저가의 저독성 천연분말은 추가적인 실험을 통하여 적절한 잠재지문 현출제로서의 가능성을 보일 것으로 사료된다.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1996년도 춘계학술발표회 초록집
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• pp.88-96
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• 1996

The characteristic analysis of fly ash generated from a fired power plant using bunker-C oil has been investigated. Ash size distribution by an optical microscopy with image processing technique, morphological shape by a scanning electron microscope(SEM) and microscope, chemical composition by the inductively coupled plasma emission spectrometry(ICP), and resistivity measurement as a function of temperature and moisture content by the resistivity meter are performed. A study of physical, chemical and electrical characteristics of bunker-C fly ash plays an important role of improving the performance of an electrostatic precipitator and protecting air pollution. The samples of bunker-C fly ash for analysis were collected from the electrostatic precipitator hopper of Ulsan Power Plant Unit 1 and Pusan Power Plant Unit 1. Mass median diameter(MMD) of bunker-C fly ash was measured 12.7${\mu}{\textrm}{m}$, while MMD of fly ash generated from the mixture of bunker-C oil(40%) and domestic anthracitic coal(60%) was 25.7${\mu}{\textrm}{m}$. The morphological structure of bunker-C fly ash consisted of fine particles of non-spherical shape. The primary chemical components of bunker-C fly ash were composed of SiO2(2.36%), Al2O3(4.91%), Fe2O3(14.33%) and C(11.84%). Resistivity of bunker-C fly ash was found to be increased with increasing temperature at the range of 100~15$0^{\circ}C$ and was measured 103~104 ohm-cm.

• Applied Microscopy
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• 제42권3호
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• pp.129-135
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• 2012

In this study, the changes in hair quality before and after Magic straight perm have been evaluated through a hair damage measurement method. For this, a healthy high school student's (age18 years) wavy hair was selected and permed on the left and right sides. Then, the changes caused by physical methods which were applied during the fl at iron-based Magic straight perm were evaluated based on the hair damage measurement method before and after the Magic straight perm. According to the protein release test after the Magic straight perm, 1.26% in average and 0.14% was observed in Cool Magic straight perm sample. In a field emission scanning electron microscopy (FE-SEM) test, saw teeth-shaped partial desquamation of cuticle cells and impurities were observed in the warm-treated hair sample. In atomic force microscope (AFM), line-profile is a method to represent roughness data on hair. According to analysis on 3-dimensional (3D) images, the hair with Cool Magic straight perm was lower than the hair with Warm Magic perm in terms of the color change of 3D images. In addition, vertical changes were observed in the hair with Cool Magic perm. As a result, irregular surface roughness was observed. This study proposed a method to minimize hair damage by cooling down the heat with the cool hair straightener as soon as the Warm Magic was finished.

• 한국연소학회지
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• 제7권4호
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• pp.1-9
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• 2002

The morphology of deposits on $15-{\mu}m$ thin SiC filaments has been investigated with SEM and compared with UV-excited laser induced broadband fluorescences in co-flowing, propane laminar diffusion flames in a reduced oxidizer environment. The homogeneous morphology of droplet-like deposits inner flame zone and the agglomeration of condensed-phase deposits and the transition to soots from grown up droplet-like precursors with approaching the flame surface can be observed in a barely sooting flame. The average size of the mature soots deposited in the luminous flame edge is scarcely dependent on their axial position in a confined flame under reduced oxidizer condition. A double structure of PAH fluorescence is observed in near-extinction flames with further decreasing of oxidizer. A comparison of the PAH fluorescence with the morphologies of deposits indicates that appearance of the "dark" hollow zone is caused by a decreased number density of developed liquid-phase large molecules and the outer weak fluorescence zone is caused by the diffusion of gas-phase small molecules.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.406-407
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• 2008

For this study, Yttrium aluminum garnet (YAG) particles doped $Eu^{3+}$ ions were prepared via the combustion process using the 1:1 ratio of metal ions to reagents. The characteristics of the synthesized nano powder were investigated by means of X-ray diffraction (XRD), Scanning Electron Microscope (SEM), and photoluminescence (PL). The various YAG peaks, with the (420) main peak, appeared at all sintering temperature XRD patterns. The YAG phase crystallized with results that are in good agreement with the JCPDS diffraction file 33-0040. The SEM image showed that the resulting YAG:Eu powders had larger sizes with the increse in the sintering temperature. The grain size was about 50nm at $1000^{\circ}C$. The PL intensity of $Eu^{3+}$ has the line peaks of 598, 610, 632nm and has main peak at 591nm.

• 패션비즈니스
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• 제12권6호
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• pp.23-33
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• 2008

The physico-chemical characteristics by bleaching treatments were assessed by several instrumental analyses such as surface morphology, chemical structural change, color change as well as tensile strength. The change of morphological characteristic was observed through scanning electron microscope(SEM). The observation of the fine structure on hair surface by SEM showed the bleached hair had much damaged to hair cuticle, and some of cuticle surface were worn away. To investigate the chemical structural changes in hair keratin, the cross-sections of hair samples were directly analysed using Fourier transform infrared microspectroscopy(FT-IRM). The results showed the cysteic acid S=O band intensity was distinctively increased by performing the bleaching treatment. The cleavage of cystine was appeared to proceed primarily through the sulfur-sulfur (-S-S-) fission whereby cysteic acid was formed as a principal oxidation products. The distribution of amide I band in hair keratin was determined by attenuated total reflectance(ATR) FT-IR mapping image. The results showed that the outer side of hair cortex was more damaged than the inner side of the hair cortex. Also, during chemical bleaching of the hair with alkaline peroxide, the hair was turned to reddish yellow due to the oxidative degradation of eumelanin. This means the eumelanin is more unstable than pheomelanin in chemical oxidation. With bleaching, the tensile strength was also reduced as a results of the chemical oxidation.

• Advances in materials Research
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• 제11권3호
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• pp.191-209
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• 2022

Very slow degradation of synthetic based polymers has created a severe environmental issue that increased awareness towards research in polymers of biodegradable property. Soy protein isolate (SPI) is a natural biopolymer used as matrix in green composites but it has limitations of low mechanical properties and high water sensitivity. To enhance mechanical properties and reduce water sensitivity of Jute-SPI composites, SPI was modified with pine rosin which is also a natural cross-linking agent. 30% glycerol on the weight basis of a matrix was used as a plasticizer. The fibre volume fraction was kept constant at 0.2 whereas the pine rosin in SPI ranged from 5% to 30% of the matrix. The effects of pine rosin on mechanical, thermal, water sensitivity and surface morphology have been characterized using various techniques. The mechanical properties and water absorbency were found to be optimum for 15% pine rosin in Jute-SPI composite. Therefore, Jute-SPI composite without pine rosin and with 15% pine rosin were chosen for investigation through characterization by Fourier transforms infrared spectroscopy (FTIR), Thermo-gravimetric analysis (TGA), X-Ray diffraction (XRD) and Scanning electron microscope (SEM). The surface morphology of the composite was influenced by pine rosin which is shown in the SEM image. TGA measurement showed that the thermal properties improved due to the addition of pine rosin. Antimicrobial test showed antimicrobial property in the composite occurring 15% pine rosin. The research paper concludes that the modification of SPI resin with an optimum percentage of pine rosin enhanced mechanical, thermal as well as water-resistant properties of jute fibre reinforced composites.

• Journal of Electrochemical Science and Technology
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• 제14권2호
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• pp.131-138
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• 2023

The carbon felt is usually hired as electrodes for vanadium redox flow battery (VRFB). In the study, surface modification of carbon felt under CO₂ atmosphere with variables of operating various temperature ranges between 700℃ and 900℃. The qualitative and quantitative analysis were carried out such as scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) to observe degree of surface modification. Result of XPS analysis confirmed increase of carbon and oxidation functional group on the surface with increase of temperature. SEM image was discovered similar phenomena. Electrochemical characteristics such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) revealed the improved electrode performance with increase of temperature. However, the electrochemical performance under treatments temperature of 900℃ was less than that of under treatment temperature of 850℃ due to weight loss at the treatment temperature of 900℃. From the CV and EIS results, the best electrochemical characteristics was at the temperature of 850℃. That of at the temperature of 900℃ was decreased due to weight loss. The energy efficiencies (EE) obtained from full cell test were 69.37, 80.76, 82.45, and 75.47%, at the temperature of 700, 800, 850, and 900℃, respectively.

• 한국재료학회지
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• 제24권2호
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• pp.111-115
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• 2014

Titanium and its alloys are useful for implant materials. In this study, porous Ti-Nb-Zr biomaterials were successfully synthesized by powder metallurgy using a $NH_4HCO_3$ as space holder and $TiH_2$ as foaming agent. Consolidation of powder was accomplished by spark plasma sintering process(SPS) at $850^{\circ}C$ under 30 MPa condition. The effect of high energy milling time on pore size and distribution in Ti-Nb-Zr alloys with space holder($NH_4HCO_3$) was investigated by optical microscope(OM), scanning electron microscope(SEM) & energy dispersive spectroscopy(EDS) and X-ray diffraction(XRD). Microstructure observation revealed that, a lot of pores were uniformly distributed in the Ti-Nb-Zr alloys as size of about $30-100{\mu}m$ using mixed powder and milled powders. In addition, the pore ratio was found to be about 5-20% by image analysis, using an image analyzer(Image Pro Plus). Furthermore, the physical properties of specimens were improved with increasing milling time as results of hardness, relative density, compressive strength and Young's modulus. Particularly Young's modulus of the sintered alloy using 4h milled powder reached 52 GPa which is similar to bone elastic modulus.

• 공업화학
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• 제31권2호
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• pp.220-225
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• 2020

모발은 여러 가지 아미노산들을 포함하는 단백질로 이루어져 있다. 자외선(UV)은 태양광선중에서 모발손상에 가장 큰 영향을 미치며 모발 노화에 주된 역할을 한다. 본 연구의 목적은 전자현미경(SEM), 공초점현미경(CLSM) 및 적외선 현미경분광법(IR micro spectroscopy)을 이용하여 정상모발에 UVB를 조사한 후 특징적인 형태학적 및 화학적 구조변화를 알아보는 것이다. 에너지 분산형 X선 분광기가 부착된 전자현미경은 자외선 조사모발의 표면이 정상모발과 비교했을 때 거칠고 높은 산소원소의 함량을 보였다. 형광 및 3차원 위상 이미지를 CLSM으로 분석한 결과 정상모발의 초록색 형광방출이 UVB 조사모발에 비해 매우 높았다. 또한 fluorescamine 형광 염색법을 통해 UVB 조사모발은 정상모발에 비해 펩타이드 결합의 파괴로 생성된 자유 아미노기가 많음을 확인할 수 있었다. UVB 조사모발의 강한 푸른색 형광은 아미노기의 함량이 높다는 것을 의미하며, 이는 CLSM에서도 관찰되었다. 따라서 fluorescamine은 UVB 조사모발에서 펩타이드 결합의 파괴를 관찰하는데 유용한 도구가 될 수 있다. 정상모발과 UVB 조사모발의 단면을 IR micro-spectroscopy를 통해 이미지 맵핑(mapping)한 결과, UVB 조사모발은 정상 모발에 비해 모발의 표면은 물론 내부에 걸쳐 디설파이드 결합(disulfide bond)의 산화가 일어나고 있음을 확인할 수 있었다. 이러한 분광학적 방법은 단독 또는 다른 분석법과 함께 모발화장품의 개발에 응용될 수 있을 것이다.