• Proceedings of the KIEE Conference
• /
• 1998.07d
• /
• pp.1276-1278
• /
• 1998

In this paper, aging characteristics of silicone rubber used for outdoor insulation have been investigated with regards to sunlight effect. For this purpose, silicone rubbers were aged under the artificial sunlight by use of xenon arc lamp(1500W) and various tests were performed such as tracking, breakdown, contact angle, stress, strain. And then, in order to elucidate the changes of material, analysis have been followed as follows; FT-IR, SEM and EDS. Regarding the effect of the sunlight, it was obs that the surface of test samples are severely da with decreased hydrophobicity, tracking resistan breakdown strength.

• Journal of Marine Bioscience and Biotechnology
• /
• v.7 no.2
• /
• pp.71-78
• /
• 2015

Sulfated polysaccharides from plants or seaweed are well known for antioxidant, anticoagulant activity or other biological activities. The aim of the present study is to optimize the condition for the isolation of water soluble polysaccharides (WSP) and evaluate the biological activity. WSP was isolated from defatted microalgae B. braunii using chlorosulfonic acid or sulfuric acid. Among WSP isolated using sulfuric acid showed the lowest the content of total carbohydrates (g/L), whereas showed the highest antioxidant activity. Also the preliminary structural analysis of WSP was performed by FT-IR spectroscopy analysis.

• Journal of Microbiology and Biotechnology
• /
• v.12 no.5
• /
• pp.760-765
• /
• 2002

Mucor miehei KCTC 6011, which grew successfully in ginseng-steaming effluents and produced a large amount of chitosan efficiently, was selected from various fungi. Approximately 120 mg of chitosan per g-dry mycelium was maximally produced in 84 h at $25^{\circ}C$ when grown in the ginseng-steaming effluent (pH 8.0) supplemented with 0.5% yeast extract and 0.002% CuSO$_4$. Chitosan produced by Mucor miehei KCTC 6011 was identified by the IR-spectra to have deacety lated approximately 56%. Viscosity and molecular weight of the chitosan were 80 cps and $1.07\times10^3$ kDa, respectively. The chitosan at 1.5 mg/ml inhibited 73.9% of the mycelium growth of Rhizoctonia solani in 60 h.

• Proceedings of the Korean Information Science Society Conference
• /
• 2006.10d
• /
• pp.152-156
• /
• 2006

기존의 가정용 건강측정기는 기기만이 독립적으로 사용되거나 기기로부터 생체정보를 전송 받아 로컬 컴퓨터에서만 처리하는 시스템이 주를 이루었다. 본 논문에서는 가정용 건강측정기 중 혈당측정기를 적외선 통신(Infrared Communication, IrDA)으로 PocketPC에 연결하여 혈당정보를 전송받는다. 이러한 정보를 PocketPC용 CDMA(Code Multiple Access) 확장 팩을 이용하여 문자메시지(Short Message Service, SMS)로 다른 휴대폰에 전송하고, 무선 랜(WLAN, IEEE 802.11)을 이용하여 웹서버에 있는 게시판에 건강측정정보를 자동 등록 하여 정보를 공유할 수 있는 시스템을 구축하였다. 특히 비공개된 혈당측정기의 프로토콜을 분석하여 통신에 사용하였으며, API(Application Programming Interface)를 제공하지 않는 CDMA 확장팩 시스템의 사용자용 프로그램을 IPC(Inter Process Communication)를 이용한 제어를 통해 필요한 태스크를 수행하는 기법을 사용하였다.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.11
• /
• pp.3788-3792
• /
• 2012

Spherical-shape melanin nanoparticles with good water-dispersibility were successfully synthesized by a simple oxidation polymerization of 3,4-dihydroxy-phenylalanin (DOPA) with $KMnO_4$. Similar features to those known from natural and synthetic melanin polymers were observed from prepared melanin nanoparticles by FT-IR, UV-Vis., and ESR spectroscopic methods. Their binding ability with several heavy metal ions from aqueous solution was quantitatively investigated, and the maximum binding capacities with melanin nanoparticles to lead, copper, and cadmium ions were obtained as 2.45, 2.17 and 1.88 mmol/g, respectively, which are much larger values than those reported from natural and synthetic melanin polymers. The large binding capacity and fast binding rate of melanin nanoparticles to metal ions can make them an excellent candidate for the remediation of contaminated water.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.1369-1370
• /
• 2007

본 논문에서는 성장된 탄소나노튜브의 열적및 화학적인 처리를 이용하여 탄소나노튜브의 화학적 변화와 구조, 분산정도를 실험 및 관찰하였다. 본 실험에 사용되어진 탄소나노 튜브는 고분산성 기술에 의하여 제조된 탄소나노튜브를 이용하였고 실험에 실시된 실험조건은 진공 중에서 열처리를 하였다. Single, Multi, Thin Mult Wall 의 탄소나노튜브를 사용하여 열처리된된 각각의 탄소나노 튜브중에 Multi Wall 이 가장큰 변화를 나타내었다. 구조적인 관찰을 위해 FE-SEM, 과 xRD를 이용하였고 화학적 결합을 알아보기위하여 FT-IR 측정을 이용하였다.

• Journal of Plant Biotechnology
• /
• v.42 no.1
• /
• pp.60-70
• /
• 2015

The aim of this study was to investigate whether fourier transform infrared (FT-IR) spectroscopy can be applied to simultaneous determination of fatty acids contents in different soybean cultivars. Total 153 lines of soybean (Glycine max Merrill) were examined by FT-IR spectroscopy. Quantification of fatty acids from the soybean lines was confirmed by quantitative gas chromatography (GC) analysis. The quantitative spectral variation among different soybean lines was observed in the amide bond region ($1,700{\sim}1,500cm^{-1}$), phosphodiester groups ($1,500{\sim}1,300cm^{-1}$) and sugar region ($1,200{\sim}1,000cm^{-1}$) of FT-IR spectra. The quantitative prediction modeling of 5 individual fatty acids contents (palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid) from soybean lines were established using partial least square regression algorithm from FT-IR spectra. In cross validation, there were high correlations ($R^2{\geq}0.97$) between predicted content of 5 individual fatty acids by PLS regression modeling from FT-IR spectra and measured content by GC. In external validation, palmitic acid ($R^2=0.8002$), oleic acid ($R^2=0.8909$) and linoleic acid ($R^2=0.815$) were predicted with good accuracy, while prediction for stearic acid ($R^2=0.4598$), linolenic acid ($R^2=0.6868$) had relatively lower accuracy. These results clearly show that FT-IR spectra combined with multivariate analysis can be used to accurately predict fatty acids contents in soybean lines. Therefore, we suggest that the PLS prediction system for fatty acid contents using FT-IR analysis could be applied as a rapid and high throughput screening tool for the breeding for modified Fatty acid composition in soybean and contribute to accelerating the conventional breeding.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.33 no.8
• /
• pp.1262-1267
• /
• 2004

An anticoagulant was purified from corn silk which has been used in Oriental Medicine. The anticoagulant from corn silk has a molecular mass of 135 kDa, and purified by 24 folds with a recovery of 11%. It was not sensitive to heat and protease treatment. However, periodate oxidation of the anticoagulant resulted in loss of activity significantly, implying that a carbohydrate was responsible for an anticoagulant activity. Galactose, glucose, mannose, fucose, glucosamine, and galactosamine were detected after acid hydrolysis by thin layer chromatography (TLC) and Bio-LC. It was confirmed that anticoagulant had OH and NH bonds by IR, supporting that the anticoagulant is composed of neutrosugar and aminosugar. Its anticoagulating activity was measured by delay in thrombin time (TT) and prothrombin time (PT) without affecting clotting by snake venom and delay in activated partial thromboplastin time (APTT). TT was more sensitive than PT, and was delayed two and three times at the concentration of 60 and 88 nM, respectively. The anticoagulating activity was reduced in the thrombin-induced clotting assay using purified fibrinogen according to the increase of fibrinogen concentration with the apparent Ki value of 23 nM.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.36 no.7
• /
• pp.675-681
• /
• 2012

The char oxidation characteristics of ashless coal with a relatively low ash content and high heating value were experimentally investigated at several temperatures (from $900^{\circ}C$ to $1300^{\circ}C$), in various oxygen concentrations (from 10% to 30%) under atmospheric pressure in a drop tube furnace. The char reaction rate was calculated from the exhaust gas concentrations (CO, $CO_2$) measured by FT-IR, and the particle temperature was measured by the two-color method. In addition, the activation energy and pre-exponential factor of ashless coal char were also calculated based on the Arrhenius equation. The results show that higher temperature and oxygen concentration result in a higher reaction rate of ashless coal, and the activation energy of ashless coal char is similar to that of bituminous coal.

• Applied Chemistry for Engineering
• /
• v.29 no.5
• /
• pp.524-532
• /
• 2018

In this study, two types of amino acids-based anionic biosurfactants such as potassium cocoyl glutamate (CTK) and sodium cocoyl glutamate (CTN) were synthesized from coconut oils and the structure elucidation of CTK and CTN was carried out by using FT-IR, $^1H-NMR$ and $^{13}C-NMR$ spectrophotometries. Measurements of interfacial properties such as static and dynamic surface tensions and emulsification activity showed that both CTK and CTN were surface-active and effective in lowering the interfacial free energy. In particular, the CTK surfactant was found to be more efficient in reducing the interfacial free energy since the larger number of CTK molecules was preferentially adsorbed at the air-water interface due to the higher hydrophobicity and larger mobility of CTK than those of using CTN, indicating possible uses in cosmetics and household products formulation.