• 한국응용과학기술학회지
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• 제30권2호
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• pp.297-304
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• 2013

Free-radical copolymerization of glycidyl methacrylate(GMA) and N-phthalimidoethyl acrylate(NPEA) were carried out at $60^{\circ}C$ in dimethylformamide(DMF) solution in the presence of benzoylperoxide(BPO) at low conversion. The polymers were characterized by IR and $^1H$-NMR. The compositions of the copolymer was analyzed by ultra violet(UV/Vis) spectrophotometry. The reactivity ratios of the monomer was determined by the application of Fineman-Ross(FR) and Kelen-T$\ddot{u}$d$\ddot{o}$s(KT) methods. The monomer reactivity ratios of the system and Alfrey-Price's resonance effect(Q) and polar effect(e) value for NIEA were determined as follow. The reactivity ratios of the monomer obtained from FR and KT are found to be $r_1$=0.87, $r_2$=0.98 and $r_1$=0.88, $r_2$=0.99 respectively. The Q and e values of poly(GMA-co-NPEM) calculated from $r_1$ and $r_2$ was Q= 1.31, e=0.75 respectively.

• 한국생활과학회지
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• 제15권2호
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• pp.275-281
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• 2006

The purpose of this study is to investigate hand and sensibility of PET treated by Ultra-Violet (UV). The 4-channel PET knit fabric was treated by a self-made UV instrument in 5cm distance with different time frames-0min, 30min, and 90min. For hand evaluation, mechanical properties were measured by the KES-FB system. The environmental condition was controlled at 29$^{\circ}C$, 75% (R.H.)-summer standard climate. Twenty female students evaluated 'roughness', 'smoothness', 'wetness', 'stiffness', 'coolness', 'touch', 'preference', and 'comfort'. The outcomes of the experiment are as follows: The surface roughness of mechanical properties showed significant differences and the value of PET irradiated by UV for 90min was highest. The order of primary hand value such as NUMERI and FUKURAMI was in a following order-Untreated > 30min treated > 90min treated. Total hand value showed that PET irradiated by UV for 90min was appropriate for using summer fabric. The results of subjective sensibility were that the untreated and 30min treated PET were recognized as similar and had a good evaluation on 'comfort', 'preference' and 'the sense of touch'. This consequence disagreed with total hand value, because it was considered that subjects' hand sensibility was dependent on the feel of smoothness.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.207-207
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• 2010

Both ZnO and GaN have excellent physical properties in optoelectronic devices such as blue light emitting diode (LED), blue laser diode (LD), and ultra-violet (UV) detector. The ZnO/GaN heterostructure, which has a potential to achieve the cost efficient LED technology, has been fabricated by using radio frequency (RF) sputtering, pyrolysis, metal organic chemical vapor deposition (MOCVD), direct current (DC) arc plasmatron, and pulsed laser deposition (PLD) methods. Among them, the PLD system has a benefit to control the composition ratio of the grown film from the mixture target. A 500-nm-thick ZnO film was grown by PLD technique on c-plane GaN/sapphire substrates. The post annealing process was executed at some varied temperature between from $300^{\circ}C$ to $900^{\circ}C$. The morphology and crystal structural properties obtained by using atomic force microscope (AFM) and x-ray diffraction (XRD) showed that the crystal quality of ZnO thin films can be improved as increasing the annealing temperature. We will discuss the post-treatment effect on film quality (uniformity and reliability) of ZnO/GaN heterostructures.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.331-331
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• 2014

3족 질화물에 기반한 발광다이오드는 비소화물이나 인화물에 비해 여러 가지 장점을 가져 각광받아왔다. 특히, (Al)GaN 에 기반한 자외선 영역 발광 다이오드는 자외선 경화, 소독 등의 여러 가지 응용 가능성을 가진다 [1]. 하지만, 심자외선 영역으로 갈수록 높은 접촉 저항과 투명전극에서의 광흡수에 의해 전류주입 효율과 광추출 효율이 감소하여 결국 외부양자 효율이 더욱 열화되는 특성을 보인다. 이는 넓은 밴드갭을 가지는 물질을 이용하여 p-(Al)GaN 층에서 오믹접촉을 이루어야만 해결이 가능하지만 아직까지 이러한 결과가 보고된 바 없다. 본 연구에서는, 우리는 넓은 밴드갭을 가지는 silicon dioxide (SiO2) 에 전기장을 인가하여 p-GaN, and p-AlGaN 층에 전도성 필라멘트를 형성하여 전기전도도를 부여하는 연구를 진행하였다. p-GaN 과 p-AlGaN 위에서 5 nm 두께의 SiO2는 schottky 한 특성과 280 nm의 파장대역에서 약 97%의 투과율을 보였다. 비록 schottky 장벽이 형성되었지만, 전기전도도가 크게 향상되었으며 심자외선 영역에서 매우 낮은 흡수율을 보였다. 이는 기존의 증착후 열처리를 거쳐 제조된 전극에 비하여 우수한 특성을 지니며 향후 심자외선 영역 발광다이오드의 p-(Al)GaN 층 위에 오믹접촉을 이룰수 있는 가능성을 제시한다.

• 분석과학
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• 제9권4호
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• pp.355-363
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• 1996

인도네시아 Manado만의 Sulawesi에서 채집한 KB cancer cell line에 대해 in vitro로 활성을 가지고 있는 것으로 추정되는 해면 Luffariella sp.로부터 Aaptamine(1) 및 Demethyl(oxy)aaptamine(2)을 분리하였다. 이들 화합물의 화학구조는 $^1H-$, $^{13}C-NMR$, $^1H-^{13}C$(1 bond) heteronuclear multiple quantum coherence spectroscopy(HMQC), electron ionization mass spectroscopy(EIMS), UV 및 IR에 의해 밝혔다.

• Journal of Astronomy and Space Sciences
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• 제21권2호
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• pp.109-120
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• 2004

2003년 9월 발사된 과학기술위성 1호의 탑재체 원자외선 분광기(FIMS)기는 우주 및 오로라 관측을 주 임무로 하고있다. 본 논문에서는 원자외선 분광기의 성공적인 천문 관측을 지원하기 위해, 탑재 컴퓨터와 원자외선 분광기와의 간단하고 신뢰성 있는 시간 동기화 기법을 소개한다. 이것은 과학기술위성 1호라는 특별한 환경 하에서 위성의 신뢰성을 줄이지 않으면서 시간 동기화를 이루도록 고안된 방법이다. 정확도가 서로 다른 두 가지 방법이 제시되었으며, 주된 방법을 사용할 수 없을 때 정확도가 낮은 방법을 사용함으로써 고장에 대처할 수 있도록 하였다. 이 기법들은 위성 시스템의 변경을 최소화하고 간단한 회로를 사용함으로써 구현에 따른 비용을 절감하고 고도의 신뢰성을 유지하도록 설계되었다.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
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• pp.257-263
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• 2006

This paper examines the physico-chemical properties and structural features of thio lignin and alcohol lignin preparations extracted from fast-growing poplar wood. The lignin preparations were characterized using UV, IR and alkaline nitrobenzene oxidation methods. The yield was higher in thiolignin due to its preparation from wood under drastic alkaline conditions and almost the total amount of alkaline degraded lignin was precipitated except acid soluble lignin. In case of ethanol lignin, structural modifications were comparatively less and form a cream colored lignin more or less similar to its original natural color. The methoxyl values were higher due to syringyl unit present in hard wood lignin in addition to guaicyl unit present in soft wood. The higher values of methoxyl content of isolated lignin revealed that it was built up of high syringyl units. The elementary analysis, methoxyl group and hydroxyl groups were presented by $C_{9}$ formula indicated that it was made up of phenyl propane monomers. Nitrobenzene oxidation of thio lignin and ethanol lignin yield more or less the chromatograms of similar pattern, except difference in relative percentage. The ultra violet spectra of lignins were quite similar, irrespective of the source and method of isolation. Infrared spectroscopy studies of poplar deltoides, thio and ethanol lignin shown different absorption bands which have been utilized for structural investigations.

• 한국식품과학회지
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• 제25권5호
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• pp.417-420
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• 1993

건조방법을 달리한 께묵(Hololeion maximowiczii) 뿌리의 색도변화에 대해서 조사하였다. Hunter value에서 분말의 경우에는 HADB가 더 진한 편이었으나 용액의 경우에는 HADB가 제일 연한 색깔을 띄었다. 수용액 색소의 420nm에서의 흡광도는 FD group이, 자외부에서 흡광도는 HADB group이 가장 강하였다. 께묵의 색소는 분말상태에서보다 용액상태에서 더 불안정하였으며, 색소분해에 대한 활성화에너지는$(90{\sim}100^{\circ}C)$ 약 20.9kcal/mole이었다.

• 한국식품과학회지
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• 제1권1호
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• pp.78-84
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• 1969

An attempt has been made to investigate the possible occurrence of aflatoxins, a group of micotoxin which are toxic metabolites produced by Aspergillus flavus, and aflatoxin like substances in fungal fermented soybean products such as meju and soybean paste. Chloroform extracts from 15 samples which has been defated with petroleum ether are subjected to separations with thin-layer chromatography on silica gel washed with methanol prior to film coating, improves the chromatographic separation and ultraviolet absorption spectral identification. In addition to fluorescencing spot having an Rf value which is same as aflatoxin $B_1$, many of the fluorescencing spots have been occurred in every sample examined. Each fluorescencing spot is scratched and the ethanol extracts are subjected to further separation with thin-layer chromatography. Each fluorescence substance is eluted with ultra violet transparent absolute ethanol and the ultraviolet absorption spectra are checked. None of the absorption curve of eluates shsow accordance with the curve of aflatoxin. 2, 4-Dinitrophenyl hydrazine reagent, Tollen's reagent and ninhydrin reagent are applied on the chromatogram- The data show that aflatoxin is not present in any of the fungal preparations examined.

• 환경위생공학
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• 제6권2호
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• pp.17-31
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• 1991

The effects of environmental agents on health are great concern for all. It was recognized that each human has differential susceptibility to environmental effects. Susceptibility are changed by many factors includin gdevelopmpntal processes, genetic factors, nutritional stratus, preexisting disease conditions, life style and personal habits. Of all factors nutritional factors seem to be the area most modifiable. Consequently, It is an area that must be more thoroughly evaluated. In this paper, nutrient and environment interactions are reviewed briefly with published literatures. This paper deals with the influence of micronutrients(energy, protein and fat), Vitamins (vitamin 4, vitamin B-complex, vitamin C, vitamin D and vitamin I) and Minerals(calcium, iron, selenium, zinc and other minerls) on environmental effects. The role of arch nutrient was assessed in modifyine the expression of environmental pollutant toxicity with available litertures. In each nutrient section, the effect of environment was considered in following agents : heavy metals(lead, cadmium, mercury, silver and etc), inorganic agents(nitwits, sulfite, fluoride and etc), organic agents(benzene, carbon tatra-chloride, aflatoxin, auto dye, dialbrin etc), Irritant gas(ozone, carbon monooxide and etc), physical agents(X-irradiation, ultra violet, temperature and noise) and insectcides. The extent to which nutritional status modifies environmental effects 3nd its converse, how envirollments affects nutritional status is very complex. In deed, at the present time there are more than 50 chelnical/phycical agents that affect the nutrient metabolism and/or have their toxicity either directly diminished or enhanced by nutrients of those agents, small number of agents for each nutrients have sufficient evidence to warrant any reasonable degree of confidence in their hypothesized associtation. With these information at this present time it is hard to conclude that the recommended dietary allowance for each nutrient should be reconsidered.