• Applied Chemistry for Engineering
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• v.31 no.2
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• pp.230-236
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• 2020

In this study, an adhesive tape with water and impact resistance for mobile devices was developed using a UV-curable urethane acrylate based polymer as a substrate. The substrate fabricated by UV-curable materials shows hydrophobicity and poor wettability, which significantly deteriorates the interface-adhesions between the substrate and acrylic adhesive. In order to improve the interface adhesion, 3-glycidoxy-propyl trimethoxysilane (GPTMS), a silane coupling agent having epoxy functional groups, was selected and incorporated into UV-curable urethane acrylate based polymer resins in various contents. The changes of the chemical composition according to the contents of GPTMS was studied with Fourier-transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) to know the surface bonding properties. Also mechanical properties of the substrate were characterized by tensile strength, gel fraction and water contact angle measurements. The peel strengths at 180° and 90° were measured to compare the adhesion between the substrate and adhesive according to the silane coupling agent contents. The mechanical strength of the urethane acrylate adhesive tape decreased as the silane coupling agent increased, but the adhesion between the substrate and adhesives increased remarkably at an appropriate content of 0.5~1 wt%.

• Journal of the Korean Wood Science and Technology
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• v.32 no.5
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• pp.29-38
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• 2004

In this study, we investigated the thermal properties of corn-starch filled polybutylene succinate-adipate (PBS-AD) bio-composites. Thermal analysis (TA) is used to describe the analytical method for measuring the chemical property and weight loss of composite materials as a function of temperature. The thermal stability of corn-starch was lower than that of pure PBS-AD. As corn-starch loading increased, the thermal stability and degradation temperature of the bio-composites decreased and the ash content increased. It can be seen that the degree of compatibility and interfacial adhesion of the bio-composites decreased because of the increasing mixing ratio of the corn-starch. As the content of corn-starch increased, there was no significant change in the glass transition temperature (T_g) and the melting temperature (T_m) for the bio-composites. The storage modulus (E') and loss modulus (E") of the corn-starch flour filled PBS-AD bio-composites were higher than those of PBS-AD, because of the incorporation of corn-starch increased the stiffness of the bio-composites. At higher temperatures, the decreased storage modulus (E') of bio-composites was due to the increased polymer chain mobility of the matrix polymer. From these results, we can expect that corn-starch has potential as a reinforcing filler for bio-composites. Furthermore, we recommend using a coupling agent to improve the interfacial adhesion between corn-starch and biodegradable polymer.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.2
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• pp.141-145
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• 2004

This study was pursued to measure skin feeling of cosmetics by mechanical methods. For this attempt, skin feeling of cosmetics such as spreading properties, tackiness, and residual greasy feeling after skin application was explored with the amount and kinds of cosmetic compositions-emulsifiers, waxes, thickeners, polyols, and oils. Furthermore, the relationship between these cosmetic compositions and viscometry of cosmetic products was studied. In case of emulsifiers, waxes, and thickeners, they showed strong correlation with both skin feeling and the value of phase angle, the property of viscometry, respectively, while polyols and oils were observed a special tendency neither skin feeling nor the property of viscometry. It leads to the conclusion that skin feeling may be corresponded to not values of a mechanical measure completely but a function of several properties. We expect that a better correlation can be discovered with additionally measured properties such as friction, volatility, etc.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.472-477
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• 2012

As people are being exposed to many types of fast food, rancid oil is a factor affecting public health. Monitoring of rancidity in frying oils needs to be done adequately. The chemical methods that are currently used require long periods of time and expertise. The development of a device that quickly and easily measures rancidity would be helpful to manage rancidity in frying oils adequately. Due to the fact that carbon nanotube (CNT) is sensitive to acid value, we used CNT as a sensing material for detecting oil rancidity. Polyethylenimine (PEI) was coated on CNT for stable measurements. Experiments were conducted at $100^{\circ}C$ after samples were cooled from $180^{\circ}C$. The results showed a strong correlation between acid values and resistances using CNT sensors. As the acid value of oils increased, the resistance of CNT sensors increased. Development of sensors using CNT may make it possible to determine the rancidity of frying oils in real-time and on site.

• Food Science and Preservation
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• v.20 no.6
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• pp.877-885
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• 2013

Wine extracts of four different berry fruits, such as mulberry, blueberry, strawberry, and raspberry, were investigated for antioxidant, anti-tyrosinase, and ${\alpha}$-glucosidase activities by using in vitro assays. Additionally, quantitative changes of ${\alpha}$-glucosidase inhibitor in mulberry wine were determined by HPLC according to mulberry cultivars and fermentation process. Among four berry wines examined, mulberry wine showed the most potent ${\alpha}$-glucosidase inhibitory activity with 69.37% at 0.23 mg/mL, while blueberry and strawberry wines exhibited the strongest inhibition against DPPH radical and tyrosinase activity, respectively. Four compounds were isolated and purified from mulberry wine by a series of isolation procedures, such as solvent fractionation, and Diaion HP-20, ODS-A, and Sephadex LH-20 column chromatographies. Among them, Comp. 4 exerted the strongest ${\alpha}$-glucosidase inhibitory activity ($I_C_{50}=31.57{\mu}M$), and its chemical structure was identified as quercetin by UV and NMR spectral analysis. Finally, the "Daeseongppong" (16.83 ppm) muberry wine had larger amount of quercetin than the "Iksuppong" (14.85 ppm) and "Cheongilppong" (8.92 ppm) mulberry wines, but their contents of three mulberry wines decreased considerably with aging process. These results suggest that mulberry wine containing quercetin acted as ${\alpha}$-glucosidase inhibitor may be useful as a potential functional wine for improving diabetic disorder.

• Fire Science and Engineering
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• v.30 no.5
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• pp.124-129
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• 2016

According to the current law, on-site flame resistant-treated interior decorations should pass the flame resistant performance test through a 45 degree combustion test from the district fire department. Although a 45 degree combustion test is the most accurate method for determining the flame resistant performance, it can be unreliable when tested on unauthorized samples. To avoid unauthorized sampling, this study suggests on-site flame resistant inspection by X-ray fluorescence spectrometer. Ten types of flame resistant paint were spread on plywoods and MDFs and the components were analyzed by X-ray fluorescence spectrometer. As a result, due to a difference amounts of substances in each paint, each flame resistant paints showed its own characteristic spectrum and the contents of each substance could be determined. On-site flame resistant inspections can be used efficiently when institutional procedures are created.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.6
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• pp.716-722
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• 1995

Near Infrared Reflectance Spectroscopy (NIRS) has been used as a tool for the rapid, accurate and nondestructive assay of small grain and forage quality analysis. The objective of this study was to establish the rapid, easy and accurate analysis method for major components of covered barley using NIRS system. NIRS used in this study was filter type instrument, Neotec 102. To obtain a useful calibration equation, standard regression between the data was analyzed by chemical analysis and by NIRS method. Standard errors of prediction (SEP) and simple correlations for unknown samples were calculated using obtained equation. SEPs for starch, $\beta$-glucan, protein and ash contents were 2.75%, 0.64%, 0.26% and 0.19%, respectively. The simple correlations for starch, $\beta$-glucan, protein and ash contents were 0.932, 0.588, 0.984 and 0.867, respectively. It was concluded that the NIRS method would be applicabl for the rapid determination of starch, protein and ash contents in barley grains.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.42-50
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• 2006

역들의 공간적 분포가 불균질하고 역의 크기가 큰 역암의 경우 암석 전체를 대표하는 물성치($E_m,\;c,\;\Phi$ 등) 구하기 위해서는 매우 큰 시험기기가 필요하다. 따라서 커다란 역을 포함하는 역암의 경우 직접 암석실내시험을 통한 물성치 산정은 현실적으로 거의 불가능하다. 이러한 문제를 극복하기 위하여 이 연구에서는 개별요소법을 이용하여 역암의 물성치를 산출하는 방법을 제안한다. 그 방법은다음과 같다. (1) 역암내의 역의 물성과 기질부의 물성을 각각 실내실험을 통하여 파악한 후 이들 (2) 두 물질의 거동양상을 구현할 수 있는 개별요소집합체의 개별요소간의 물성을 결정한다. (3) 역의 함량, 크기 모양 공간적 분포양상등의 역암 조직과 유사한 개별요소 수치해석시료를 만든 후, (4) 이를 수치 해석실험 (이축압축실험)에 사용한다. 이러한 수치해석실험을 통해 현재까지 만들어진 결과는 다음과 같다. 첫째, 역의 강도가 기질의 강도보다 높은 역암의 경우, 역의 양이 증가할수록 일축압축강도, 내부 마찰각, 점착력이 증가하지만 증가 양상은 선형이 아니다. 탄성계수의 경우 역의 양과 상관 없이 변화하지 않는다. 둘째, 역과 기질 사이 표면의 점착력이 약할 경우 이러한 표면에서 최초 미세 균열이 형성되기 시작하므로 이 점착력은 물성치를 산출하는 중요한 인자이다. 따라서, 향후 이에 대한 자세한 연구가 필요하다고 판단된다. 결론적으로,설계 또는 시공시 직접시험에 의한 물성치의 파악이 어려운 역암 또는 직접시험을 위해 대량의 시료를 필요로 하는 함력 미고결지층, 핵석층, 풍화암과 같은 시료의 물성치는 별도로 측정된 물성들 (예, 역과 기질)을 이용한 개별요소법을 통해 구할 수 있다.로 나타났다.TEX>, DIN/DIP비 표층수 $23.91\pm3.42$, 저층수 $23.43\pm3.38$이었으며, 전반적으로 해역별 수질기준 I등급 내지는 II등급을 유지하고 있었고, 공간적으로는 외해측으로 갈수록 외해수와 혼합 확산되어 양호한 수질을 나타내었다. 장기적인 변동특성은 세그룹으로 구분되어진다.기 실험결과 용출용매로 증류수와 해수를 이용했을 때, 제강 슬래그에서 용출되는 납, 구리, 카드뮴, 수은의 용출 경향의 차이를 확인할 수 있었고 이에 따라서, 납, 구리, 카드뮴의 용출 유해성은 낮기 때문에 해양구조물로의 제강슬래그 유효이용은 적합할 것으로 판단되었다.im80%$로 계산되었다. 열형광선량계로 측정된 방사선량은 각각 1.8, 1.2, 0.8, 1.2, 0.8 (70 cm 거리) cGy로 측정되었으며, 환자의 복부 표면에서의 서베이메터를 이용한 측정량은 10.9 mR/h였다. 차폐구조물의 사용 시 전체 치료 동안에 태아선량은 약 1 cGy 정도로 평가되었다. 결론 : AAPM Report No.50의 자료에 따르면, 임산부의 방사선 치료 시 태아의 방사선 피폭선량은 5 cGy 이하일 경우에 방사선 피폭에 따른 태아의 위험이 거의 없는 것으로 제시되고 있다. 본원에서 차폐 구조물을 설치하였을 경우에 측정된 태아선량은 약 1 cGy로 측정되었고, 고안된 차폐구조물은 태아에 도달하는 방사선량을 감소시키기에 적합한 설계임이 입증되었다. 아니라 일반종합병원에서도 CTX-M형 ESBL 생성 E. coli와 K. pneumoniae가 존재하며 확산 중임을 시사한다. 앞으로 CTX-M형 ESBL의 만연과 변종 CTX-M형 ESBL의 출연을 감시하기 위한

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.2
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• pp.196-201
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• 1993

In order to investigate some chemical components, higher alcohols, ethyl acetate and volatile compounds of Vitis vinifera red wines were analyzed by HPLC, GC and GC-MS. During the process of ripening for the content of wine and acids were much changed, particurally the content of tartaric acid was decreased largely. Content of total phenolics and phenol flavonoid in wines which manufactured with Malbec varieties as 470mg/L and 245mg/L respectively, was higher than those in Cabernet sauvignon (310mg/L, 135mg/L) and Cabernet franc (425mg/L, 125mg/L) wines, and nonflavonoid was higher in Cabernet franc wine(300mg/L) than in others. Content of acetaldehyde was higher in Malbec wine (33mg/L) than in Cabernet sauvignon (26mg/L) and Cabernet franc (28mg/L) wines. Amount of methyl alcohol, propanol and isoamyl alcohol were higher in Cabernet sauvignon wine than in others, and isobutanol was more in Malbec wine(64mg/L), ethyl acetate was more in Cabernet franc wine as 35mg/L than in Malbec(28mg/L) and in Cabernet sauvignon (23mg/L) wines. Volatile compounds were isolated about 87~91 varieties from concentrates of three red wines by GC, and thirty-five compounds including terpine-4-ol were identified by GC-MS.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.2
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• pp.127-138
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• 2000

To enable rapid and convenient soil test, new soil analytical methods, which require only one instrument, UV/Vis spectrophotometer, were developed and named "Soiltek KA-P spectrophotometric methods". The Soiltek$^{(R)}$ KA-P spectrophotometric method was compared with standard method of RDA in analytical capability for soil chemical properties. Using the 78 soils collected from upland, paddy, orchard, and vinyl house soils, soil organic matter, exchangeable K, Ca, and Mg. CEC, available $SiO_2$, and nitrate were analyzed by the two methods. The color stability(ratio of the absorbance at elapsed time t to the absorbance at time t=0) of organic matter. Ca, Mg, and available $SiO_2$ decreased to about 2% within one hour. However, that of exchangeable K, CEC, and nitrate remained constant. The results obtained with Soiltek$^{(R)}$ KA-P spectrophotometric method showed highly significant correlation with those measured by the standard method of RDA($R^2$ >0.9501), in which the slopes were near unity of $1.0{\pm}0.05$. The standard deviation values of organic matter, exchangeable K, Ca, and Mg, CEC, available $SiO_2$, and nitrate were apparently lower than ${\pm}1.8gkg^{-1}$, ${\pm}0.05cmol^+kg^{-1}$, ${\pm}0.18cmol^+kg^{-1}$, and ${\pm}0.13cmol^+kg^{-1}$, ${\pm}1.0cmol^+kg^{-1}$, ${\pm}5.0mgkg^{-1}$, and ${\pm}10.0mgkg^{-1}$, respectively. All the measurements showed coefficients of variation of less than 7~17% and were within the confidence level of 95%, which means both the methods are precise. Considering the relative simplicity, low cost, precision and accuracy, the proposed Soiltek$^{(R)}$ KA-P spectrophotometric methods could be recommended as an alternative to standard method.