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코로나 방전 또는 상용화제가 처리된 폴리프로필렌/케나프 섬유 펠트의 물성 연구
구선교(Sun Gyo Ku),박병수(Byeoung-Soo Park),김동원(Dong Won Kim),김기성(Ki Sung Kim),김연철(Youn Cheol Kim) 한국고분자학회 2016 폴리머 Vol.40 No.5
폴리프로필렌(polypropylene, PP)/케나프 섬유(kenaf fiber, KF) 펠트와 폴리우레탄(polyurethane, PU) 바인더의 계면 접착특성 향상을 위해 코로나 방전처리와 상용화제로 말레인산 무수물(maleic anhydride, MAH)이 그래프트된 PP-g-MAH가 적용되었다. PU 바인더의 반응온도와 시간 선정을 위해 DSC를 이용하여 등온 실험을 수행하였다. 코로나 방전처리와 상용화제 적용에 따른 PP/KF/PU 복합체의 기계적 물성 변화를 고찰하기 위해 인장, 굴곡 및 충격 특성을 평가하였다. 코로나 방전처리 및 PP-g-MAH 처리의 경우 인장특성과 충격특성이 개선되는 경향을 나타내었다. 기계적 물성의 증가는 코로나 방전처리 및 PP-g-MAH에 의한 PP의 산소기 도입으로 mPP/KF와 PU 바인더간의 상용성이 개선되었기 때문으로 해석할 수 있고, 파단면의 SEM 사진으로부터 확인되었다. In order to improve the interfacial adhesion property between polypropylene (PP)/kenaf fiber (KF) felt and polyurethane (PU) binder, corona discharge treatment and PP-g-MAH grafted maleic anhydride (MAH) were applied as a compatibilizer to PP/KF felt. Isothermal experiments were carried out by using differential scanning calorimetry (DSC) to determine the reaction temperature and time for PU binder. Tensile, flexural and impact properties were evaluated to analyze the mechanical properties of PP/KF/PU treated by corona discharge and PP-g-MAH. In case of modified-PP (mPP)/KF/PU composite treated by corona discharge and PP-g-MAH, the tensile and impact properties were improved. It may be because when the corona discharge was applied to the mPP/KF felt, the compatibilizing ability between the mPP/KF and PU binder increased due to the insertion of oxygen group in PP chain. The interface adhesion properties of the mPP/KF/PU composites were identified by SEM images of the fracture after the tension test.
EMLA�cream의 도포마취 효능에 관한 임상적 연구
김희진,강덕일,이병채,설재헌,정현구 朝鮮大學校 口腔生物學硏究所 2001 口腔生物學硏究 Vol.25 No.2
It has been suggested that all intra-oral topical anaesthetics are equally effective on reflected mucosa, however EMLA cream (an acronym for eutectic mixture of local anaesthetics), which was developed in the 1980, and produces surface anaesthesia of skin, has been shown to be more effective than conventional topical anaesthetics when used on attached gingivae. This investigation studied the effects of EMLA cream and commonly used topical an esthetics on normal mucosa using an objective measuring scale. The following were tested : 5% EMLA cream, 10% lidocaine, 20% benzocaine, and a placebo, 5% EMLA cream was superior in performance to all other topical anesthetics.
표면 개질된 활성탄소 섬유의 Propylamine 탈착과 XPS 분석
김병구,양범호,Kim Byeoung-Ku,Yang Burm-Ho 한국연초학회 2005 한국연초학회지 Vol.27 No.1
Activated carbon fiber (ACF) was surface modified by nitric acid to improve the adsorption efficiency of the propylamine. The adsorption amount of propylamine of the modified ACF increased $17\%$ more than that of as-received ACF. Desorption of propylamine from the propylamine saturated ACF was occurred in two steps, the first step started arround $50^{\circ}C$ showing the desorption of physically adsorbed propylamine and the second step started at $200^{\circ}C$ showing the decomposition of chemically adsorbed propylamine. Total desorption amount of propylamine from the modified ACF was larger than that of the as-received ACF because of increased functional groups. The oxygen and nitrogen contents on the modified ACF increased by 1.5 and 3 times compared with the as-received ACF. A part of propylamine adsorbed on ACF formed pyridine-like or pyrrolic structures with 2 carbons exposed on the surface of the ACF. It was found that propylamine reacted with strong or weak acidic functional groups such as -COOH or -OH existed on ACF surface.
張基運,金炳九 충남대학교 농업과학연구소 1989 농업과학연구 Vol.16 No.1
This experiment was conducted to study the relation between the equilibrium moisture contents and the hygroscopic components in the various tobacco matters such as NC-82, Br-21, R.T.S., and puffed stem. The order of the high equilibrium moisture contents was the puffed stem, R.T.S., NC-82, and Br-21. The H-1 grades of NC-82 and Br-21 contained high contents of total sugar had higher equilibrium moisture contents than others. The moisture contents in NC-82 and Br-21 were increased at higher temperature, 30℃ than 20℃. The grades with high amounts of water extracts and total sugar affected to increase the equilibrium moisture contents in NC-82 and Br-21. In conclusion, the equilibrium contents were related to the structure of tobacco matter, the grades, the temperature, and the amount of some chemical components such as water extracts and total sugar of the leaf tobacco.
張基運,金炳九 충남대학교 농업과학연구소 1989 농업과학연구 Vol.16 No.1
Six cigarette brands produced in Korea and U.S.A. were studied to find the effects of relative humidity, moisture sorption time, temperature, and the amounts of water extracts and total sugar in the brands on the equilibrium moisture contents. The equilibrium contents were higher in the domestic brands than foreign ones and the sorption rates of moisture were faster in the domestic cigarettes. The Korean brands with high contents of water extracts and total sugar had higher equilibrium moisture contents in the range of RH 40-80% at 20℃ for 72hours. These are the reasons that Korean brands contain higher ratio of flue-cured tobacco and American brands are blended with higher ratio of Burley tobacco.
김병구,신해근,서정규,이문용,지상운,Kim, Byeoung-Ku,Shin, Hae-Geun,Seo, Jung-Kyu,Lee, Moon-Young,Ji, Sang-Un The Korean Society of Tobacco Science 2009 한국연초학회지 Vol.31 No.1
Activated carbon fiber (ACF) was surface modified by nitric acid to improve the adsorption efficiency of the propylamine. Functional groups and textural properties of modified ACF were investigated. The total surface acidity increased about 7 times to that of as-received ACF by modification with 1 M nitric acid solution, carboxylic and phenolic groups mainly increased. However, the specific surface areas and the total pore volumes of the modified ACFs were decreased by 5-8% due to the increased blocking (or demolition) of micropores in the presence of newly introduced complexes. Despite the decrease of textural properties, it was found that the amount of propylamine adsorbed by the modified ACFs was increased by approximately 17%. The oxygen and nitrogen contents on the modified ACF increased by 1.5 and 3 times compared with the as-received ACF. From the XPS results, it was observed that propylamine reacted with strong or weak acidic groups, such as -COOH or -OH on the ACF surfaces, resulting in the formation of pyrrolic-, pyridonic- or pyridine-like structures.
Measurement of the Apparent Density of Shred and Void Fraction in a Tobacco Column
Oh, In-Hyeog,Jeh, Byong-Kwon,Ra, Do-Young,Kwak, Dae-Keun,Kim, Byeoung-Ku,Jo, Si-Hyung,Rhee, Moon-Soo The Korean Society of Tobacco Science 2007 한국연초학회지 Vol.29 No.1
The measurement of physical properties such as apparent density and void fraction of tobacco materials, which is so bulky, is a main theme with regard to tobacco process, quality control, cigarette combustion and smoke generation. Except Solution Impregnation Method, there was no alternative method for measuring those properties in the porous material so far. However, experimental processes of that method are so complicated as to cost much time and labor, the main solution such as mercury to apply to the method is usually very hazard. Therefore, we had developed a new method to determine them easily in our other paper by the mathematical equations derived from the Ergun equation for the purpose of it, and then already evaluated our method through applying some basic data from Muramatsu et at. (1979) with regard to our developed equations. Then, we found our method best fit to experimental one (Oh et al., 2001). In this study we tried to establish our method to conveniently determine those physical properties. Especially, we have focused on the development the easy way to measure surface area and the volume of single shred in a tobacco column. As a result of that, we found that the computer image analyzer was best fit for it. Then, we have finally determined apparent density and void fraction for our domestic tobacco shred.